DATE 
PLACE 
TITLE 
SPEAKER 
HOST 
2013

11 Jul 2013

(507)

TBA
Abstract
TBA

Dr. Jennifer Nebreda
U. Complutense Madrid

Prof. A. Ramos

27 Jun 2013

(507)

Discrete symmetry, topological charges and the angular momentum of the photon
Abstract
TBA

Dr. Albert Ferrando
U. Valencia

Dr. M. A. GarciaMarch

20 Jun 2013

(507)

Confronting the quantum manybody problem: an overview
of the coupled cluster method and its applications in physics
Abstract
Examples of quantum manybody systems abound in Nature. Thus, it is clear that in
fields like molecular, solidstate, and nuclear physics most of the fundamental objects of
discourse are interacting manybody systems. But even in elementary particle physics
one is usually dealing with more than one particle. For example, at some level of reality a
nucleon comprises three quarks interacting via gluons and surrounded by a cloud of
mesons, which are themselves made of quarkantiquark pairs. Even more fundamentally,
even the “physical vacuum” of any quantum field theory is endowed with an enormously
complex infinite manybody structure due to virtual excitations. A key central role in
modern physics is thus occupied by quantum manybody theory, where we are especially
interested in the possible existence of any universal techniques that are powerful enough
to treat the full range of manybody and fieldtheoretic systems. One such method is the
coupled cluster method [14]. This has become one of the most pervasive (possibly the
most pervasive), most powerful, and most successful of all fully microscopic formulations
of quantum manybody theory. It has been applied to more systems in quantum field
theory, quantum chemistry, nuclear, subnuclear, condensed matter and other areas of
physics than any other competing method. It has yielded numerical results which are
among the most accurate available for an incredibly wide range of both finite and
extended systems on either a spatial continuum or a regular discrete lattice. In this
seminar I aim to give an overview of the method itself and some illustrative examples of its
power and range of applicability. Specific examples will include finite atomic nuclei and
nuclear matter, the electron gas, pionnucleon pseudoscalar field theory, U(1) lattice
gauge field theory, and spinlattice models of quantum magnetism.
References
[1] R.F. Bishop and H.G. Kümmel, Physics Today 40(3), 52 (1987).
[2] R.F. Bishop, Theor. Chim. Acta 80, 95 (1991).
[3] R.F. Bishop, in "Microscopic Quantum ManyBody Theories and Their Applications," edited by
J. Navarro and A. Polls, Lecture Notes in Physics 510, SpringerVerlag, Berlin, p.1 (1998).
[4] D.J.J. Farnell and R.F. Bishop, in “Quantum Magnetism,” edited by U. Schollwöck, J. Richter,
D.J.J. Farnell and R.F. Bishop, Lecture Notes in Physics 645, SpringerVerlag, Berlin, p. 307
(2004).

Dr. R. Bishop (Feenberg Medal)
U. Manchester

Prof. A. Polls

6 Jun 2013

(507)

Heavy flavor diffusion in a hot hadronic gas
Abstract
Current abstract:
I will review the recent results concerning the
diffusion and relaxation of heavy mesons in a hadronic gas
at finite temperature. I will describe the dynamics of D
and B mesons interacting with light mesons and show how the
drag force and diffusion coefficients can be extracted using
the FokkerPlanck equation. Results including baryons will also
be presented.

Dr. J.M. TorresRincon
IEECUAB

Prof. J. Soto

27 May 2013

(507)

Illuminating the neutron skin
Abstract
Current abstract:
An accurate determination of the distribution of neutrons in the atomic nucleus has proven
elusive despite decades of study. This gap in our knowlege is an impediment to obtaining a
detailed understanding of nuclear structure, neutron rich matter and neutron stars. This
talk will present a new measurement of the matter distribution of 208Pb using coherent
neutral pion photoproduction near the reaction threshold. The measurement utilised the large
acceptance Crystal Ball detector at the MAMI tagged photon beam facility in Mainz, Germany.
Preliminary measurement of the size and diffuseness of the neutron skin forming on the
surface of 208Pb will be presented. Future plans will also be discussed.

Prof. Daniel Watts
U. Edinburgh

Prof. M. Centelles

24 May 2013

(507)

Nucleon Resonance Structure from Exclusive Meson Electroproduction
Abstract
Current abstract:
The CLAS detector at Jefferson Lab is a unique instrument, which has provided the lion's share of the world's data on meson photo and electroproduction in the resonance excitation region. The electroexcitation amplitudes for the lowlying resonances $P_{33}(1232)$, $P_{11}(1440)$, $D_{13}(1520)$, and $S_{11}(1535)$ were determined over a wide range of Q^2 < 5.0 GeV^ in a comprehensive analysis of exclusive singlemeson ( $\pi^+n$, $\pi^0p$) reactions in the electroproduction off protons. Further, CLAS was able to precisely measure $\pi^+\pi^p$ electroproduction differential cross sections provided by the nearly full kinematic coverage of the detector. The electrocouplings of the $P_{11}(1440)$ and $D_{13}(1520)$ excited states are determined from the exclusive$\pi^+\pi^p$ reaction. Consistent results on the electrocouplings from twoindependent analyses (single and doublepion electroproduction) have provided compelling evidence for the reliable extraction of the $N^*$ electrocouplings. Preliminary results on the electrocouplings of the $S_{31}(1620)$, $S_{11}(1650)$, $D_{33}(1700)$, and $P_{13}(1720)$ states have recently become available. Theoretical analyses of these results have revealed that there are two major contributions to the resonance structure: a) an internal quark core and b) an external mesonbaryon cloud. These CLAS results have had considerable impact on QCDbased studies on $N^*$ structure and in the search for manifestations of the dynamical masses of the dressed quarks. Future CLAS12 $N^*$ structure studies at high photon virtualities will considerably extend our capabilities in exploring the nature of confinement in baryons.

Dr. Phil Cole
U. Idaho (USA)

Dr. B. JuliaDiaz

30 Apr 2013

(507)

A study of coherently coupled twocomponent condensates
Abstract
We present a selfconsistent study of coherently coupled twocomponent BoseEinstein condensates. The presence of the Rabi coupling prevents phase separation, but introduces a (secondorder) phase transition between an unpolarized to a polarized ground state. We analyze the excitation spectrum and the structure factor along the transition for a homogeneous system, pointing out the main differences between a coherently coupled gas and a twocomponent mixture. Lastly, we discuss how the situation changes in the inhomogeneous case, when the trapping potentials for the two components are the same or different, and especially when one of them is an optical lattice.

Dr. M. Abad
BEC/U. Trento

Prof. M. Guilleumas

25 Apr 2013

(507) (RESCHEDULED)

Heavy flavor diffusion in a hot hadronic gas
Abstract
Current abstract:
I will review the recent results concerning the
diffusion and relaxation of heavy mesons in a hadronic gas
at finite temperature. I will describe the dynamics of D
and B mesons interacting with light mesons and show how the
drag force and diffusion coefficients can be extracted using
the FokkerPlanck equation. Results including baryons will also
be presented.

Dr. J.M. TorresRincon
IEECUAB

Prof. J. Soto

18 Apr 2013

(507)

Tunneling, self trapping and manipulation of higher modes of a BEC in a double well
Abstract
Current abstract:
We study the dynamical behavior of four modes of atomic BoseEinstein condensates (BEC) trapped in a one dimensional double well trap. A general Hamiltonian is given in terms of the creation and annihilation operators as well as in the macroscopic limit. Three regimes of interaction are studied, each showing different degree of tunneling and self trapping in the two energy levels. Influence of initial conditions in the ground modes on the excited modes is also studied. The presence of chaos in the system is also noted.

Dr. J. Gillet
U. Okinawa

Dr. M. A. GarciaMarch

9 Apr 2013

(507)

NucleonNucleon scattering from the dispersive N/D method: Nexttoleading study
Abstract
Current abstract:
We consider nucleonnucleon interactions from Chiral Effective Field Theory applying the N/D method. We calculate the discontinuity of the NN partialwave amplitudes across the lefthand cut (LHC) by including onepion exchange, onceiterated OPE and leading irreducible twopion exchange calculated in Chiral Perturbation Theory. We discuss both uncoupled and coupled partialwaves. Phase shifts and mixing angles are typically quite well reproduced, and a clear improvement of the results obtained previously with only OPE is manifest. We are also able to predict the Swave effective ranges, once the scattering length are fixed without any other experimental input. In this way, we justify the correlation between scattering length and effective range in Swaves making use of the analytical properties of NN partial waves without any further assumption. We also show that the contributions to the discontinuity across the LHC are amenable to a chiral expansion.

Prof. J. A. Oller
U. Murcia

Prof. A. Ramos

13 Mar 2013

(507)

Halfday meeting on ultracold atoms @ BCN
Abstract
Current abstract:

V. Ahufinger, G. Astrakharchik, J. Douglas
B. JuliaDiaz, P. Massignan, A. Sanpera
UAB/UPC/UB/ICFO

Dr. B. JuliaDiaz

7 Mar 2013

(507)

Integrated MachZehnder interferometer with BoseEinstein condensates
Abstract
Quantum mechanical particlewave duality allows the construction of interferometers for matter waves, which may complement lasers in precision measurement devices such as gravimeters or gyroscopes. This requires the development of new atomoptics analogs to beam splitters, phase shifters, and recombiners. Realizing and integrating these elements into a transportable device has been a longstanding goal.
I will present our recent realization of a full MachZehnder sequence with trapped atomic BoseEinstein condensates (BEC) confined on an atom chip. Particle interactions in our BEC matter waves lead to an intrinsic nonlinearity, absent in photon optics. We exploit these interactions to generate a nonclassical state with reduced number fluctuations, which is injected into the interferometer. Making use of spatially separated wave packets, a controlled phase shift is applied and read out by a diabatic matter wave recombiner. We demonstrate coherence times a factor three beyond what is expected for a classical coherent state, highlighting the potential of entanglement as a resource for metrology.

Dr. JeanFrancois Schaff
TU Wien

Dr. B. JuliaDiaz

26 Feb 2013

(507)

Why is lead so kinky?
Abstract
The charge radius of even lead isotopes changes abruptly across the N=126 shell gap. A full theoretical explanation for this kink in charge radii is still missing. Recent experimental data on polonium isotopes suggests that "kinkiness" is a rather general feature in this mass region. We will argue that the mechanism underlying this phenomenon is the occupation of the neutron 1i11/2 orbital. I will review a few mechanisms that could provide such an occupation and suggest further experimental evidence that can validate this picture.
Reference:
P. M. Goddard, P. D. Stevenson, and A. Rios,
Phys. Rev. Lett. 110, 032503

Dr. Arnau Rios
U. Surrey

Prof. A. Polls

22 Jan 2013

(507)

Weak response of cold symmetric nuclear matter at threebody cluster level
Abstract
I will present our study of the Fermi and GamowTeller responses of cold symmetric nuclear matter within a unified dynamical model, suitable to account for both shortand longrange correlation effects. The formalism of correlated basis functions has been used to construct twobody effective interactions and onebody effective weak operators. The inclusion of the threebody cluster term allowed for the incorporation in our scheme of a realistic model of three nucleon interactions, referred to as Urbana IX. Moreover, our results show that the sizable dependence of the effective weak operator on the details of the correlation functions is in fact unphysical, an disappears once the threebody cluster term is taken into account.

Dr. Alessandro Lovato
Argonne National Laboratory

Prof. A. Polls

09 Jan 2013

(507)

Condensate fraction in ultracold Fermi atoms and in neutron matter
Abstract
We analyze theoretically the condensate fraction of fermionic pairs
for a uniform twocomponent atomic
Fermi gas in the crossover from the BardeenCooperSchrieffer (BCS)
state of weaklyinteracting Cooper
pairs to the BoseEinstein Condensate (BEC) of molecular dimers. We
derive explicit formulas for condensate
density and condensate fraction as a function of the chemical
potential and the energy gap both in three [1] and two dimensions [2].
We also consider the case of threecomponent atomic Fermi superfluid
with U(3) invariant attractive interaction [3].
Finally, we investigate the condensate fraction of fermionic pairs in
the uniform neutron matter [4] and in the crust of neutron stars.
[1] L. Salasnich, N. Manini, A. Parola, Phys. Rev. A 72, 023621 (2005).
[2] L. Salasnich, Phys. Rev. A 76, 015601 (2007).
[3] L. Salasnich, Phys. Rev. A 83, 033630 (2011).
[4] L. Salasnich, Phys. Rev. C 84, 067301 (2011).

Prof. Luca Salasnich
U. Padova

Dr. B. JuliaDiaz

2012

15 Nov 2012

(507)

Desorption dynamics of photoexcited atoms in helium nanodroplets
Abstract
Superfluidity is a widely known and accepted phenomenon displayed by quantum liquids such as helium at low temperatures. However, it is not completely clear how superfluidity appears at the microscopic scale and whether a helium cluster made of a few thousand atoms presents all the features characteristic from superfluid behavior.
The motion of a silver atom inside a helium nanodroplet upon photoexcitation presents a unique opportunity to probe superfluidity in finite clusters, both experimental and theoretically. Because the silver atom resides in the bulk of the drop, the velocity at which it is expelled depends critically on the interaction with the surrounding helium and the damping it introduces.
In this talk I will present results for the dynamical desorption of silver computed by means of a timedependent density functional approach. This allow us to examine the behavior of He excitations during the process and compare the limiting velocity of the impurity with the experimental data.

David Mateo
ECM


08 Nov 2012

(507)

High momentum components in the nuclear symmetry energy
Abstract
The shortrange and tensor correlations associated to realistic nucleonnucleon interactions induce a population of highmomentum components in the manybody nuclear wave function.We study the impact of such highmomentum components on bulk observables associated to isospin asymmetric matter. The kinetic part of the symmetry energy is strongly reduced by correlations when compared to the noninteracting case. The origin of this behaviour is elucidated using realistic interactions with different shortrange and tensor structures.

Arianna Carbone
ECM


24 Oct 2012

(507)

Strongly correlated ultracold bosons as impurities immersed in a BoseEinstein condensate
Abstract
Impurities, such as fermions or ions, immersed in a cloud of weakly interacting bosons
forming a condensate have attracted recent interest because they conform versatile,
highly controllable, and experimentally feasible systems for studying quantum correlations.
In this talk I will discuss an exact many body description of a mixture of ultracold bosons in
which a few strongly interacting atoms play the role of impurities immersed in a second species of a
much bigger cloud of weakly interacting atoms. The latter species acts as a tunable environment,
whose effect over the impurities can be controlled through the interspecies interactions. What is the
behaviour of the quantum correlations within or between both species through the process of phase
separation? How do they behave along with the dynamics of the impurities within the environment?
Can we mimic the tools of quantum optics to analyse these quantum correlations? Within the
introduced theoretical framework I will offer answers to these questions. I will also derive a
simple semiclassical description of the system and henceforth discuss the experimental
feasibility and technological applications of such a system.

Dr. Miguel Angel Garcia March
ECM


8 Oct 2012

(507)

Gaussian Expansion Method and application to 4He tetramer system
Abstract
Many important problems in physics can be addressed by solving with high
precision, Schroedinger equation for fewbody systems. For the study of
such problems with accurate calculations required, the Gaussian Expansion
method (GEM), an ab initio variational method for fewbody systems, was
proposed by Kamimura [1]. When one proceeds to fourbody systems,
calculation of the Hamiltonian matrix elements become much laborious. In
order to make the fourbody calculation tractable even for complicated
interactions, I proposed the infinitesimallyshifted Gaussian lobe basis
function [2]. The GEM with the techinique of the infinitesimallyshifted
Gaussian lobe basis function have been applied to various three, four
and fivebody calculations in hypernuclei, the fournucleon system, ultra
cold atom systems, etc. In this seminar, I will give a talk about our
method, GEM, and application to ultra cold atom physics, especially,
tetramer of 4He atoms using realistic 4He4He atomic potential.
[1] M. Kamimura, Phys. Rev. A38 (1988) 621.
[2] E. Hiyama, Y. Kino and M. Kamimura, Prog. Part. Nucl. Phys. 51 223
(2003).

Dr. Emiko Hiyama
RIKEN (Japan)

Prof. A. Parreño

26 Jun 2012

(505)

Nuclear physics from first principles: a status report
Abstract
I will discuss recent progress in calculating nuclear physics
interactions and properties using lattice QCD. I will focus on an
area in which lattice QCD will soon be competitive with experiment;
specifically, I will consider simple hypernuclear processes which are
essential input into the nuclear equation of state relevant for a
description of dense astrophysical objects, and very recent
calculations of the spectrum of light nuclei and hypernuclei
at the flavor SU(3) symmetric point.

Dr. Silas Beane
U. New Hampshire

Prof. A. Parreño

20 Jun 2012

(507)

Momentum and density dependence of nuclear mean field and equation
of state of nuclear matter.
Abstract
Nuclear mean field is the fundamental quantity in the study of nuclear
matter. Momentum dependent mean field that reproduces the flow data
corresponds to a value of incompressibility of the nuclear matter which is
in agreement with the giant monopole resonance studies.The behaviour of
the mean field at Fermi momentum is directly connected with the equation
of state of nuclear matter. The existing deficiencies in our present
understanding on these two important aspects,namely, momentum and density
dependence of nuclear mean field shall be discussed in the present talk.

Dr. T.R.Routray
U. Sambalpur

Prof. X. Vinyas

21 May 2012

(507)

How to speed up quantum adiabatic processes
Abstract
Quantum adiabatic processes are slow and ideally robust versus
parameter variations, but often they take too long or get spoiled by
noise and decoherence. I'll review different "shortcuts to
adiabaticity" that speed them up for atomic transport, expansions, or
internal state preparation, emphasizing our most recent results

Dr. Juan Gonzalo Muga
U. Pais Vasco

Prof. Joan Martorell

25 Aprl 2012

(507)

Heavy meson phenomenology in a constituent quark model
Abstract
An investigation of heavy meson properties within the framework of a nonrelativistic
constituent quark model is presented. We study possible assignments of the new particles
as q q states. Besides meson spectra, we calculate other properties that can provide
valuable
information on the meson structure as electromagnetic decays and strong and weak
reactions.
The description of theoretical approaches used and the discussion of some relevant results,
comparing them with the experimental data and also with the results coming from
diﬀerent theoretical approaches, can be followed along the talk.

D. Jorge Segovia
U. Salamanca

Dr. B. JuliaDiaz

1619 Aprl 2012

(507)

Curs: Emergent Phenomena on quantum manybody physics
Abstract
Everyone is familiar with single particle quantum mechanics from
course work: we all learn
about quantum tunneling through a barrier, probability waves, and the
Hydrogen atom as
undergraduates,and move on as graduate students to path integrals, the
Dyson series,
and density matrix formalism. But what are the quantum properties of
many particles? Is
it enough to write down the symmetrization postulate and decide that
the Universe is divided
into bosons and fermions, and derive a quantum version of statistical
mechanics? Or, is there
more to the story? In this course, we will explore the new, emergent
properties that appear in
quantum many body systems, from quantum phase transitions to vortices
in quantum hydrodynamics.

Prof. Lincoln D. Carr
Colorado School of Mines & U. Heidelberg

Dr. B. JuliaDiaz

1 Feb 2012

(507)

A new interpretation for the Ds2(2573), the prediction of novel exotic charmed mesons and narrow N*, Lambda* resonances around 4.3 GeV
Abstract
In this talk we review the vectorvector interaction within the hidden gauge formalism in a coupled channel unitary approach. We study the vectorvector interaction for all the sectors not studied before: /C/= 0; /S/ = 1 (hiddencharm), /C/= 1, /S/= 1, and the flavor exotic sectors /C/= 1; /S/= 1,2 and /C/=2; /S/= 0,1,2. By looking for poles in the complex plane, we find nine states, four of them in the /C/= 1; /S/= 1 sector, where one can be identified with the /D//s/2*(2573) and it is interpreted as a /D/*/K/* molecular state. The other five resonances are found in the flavor exotic sectors /C/ = 1; /S/ = 1, /C/ = 2; /S/ = 0,1 and can be considered as /D/*/K?/*, /D/*/D/* and /D//s/*/D/* molecular states. Nevertheless, there is not experimental evidence of such states yet. In addition, a
series of mesonbaryon dynamically generated relatively narrow N^* and Lambda^? resonances are predicted
around 4.3 GeV in the hidden charm sector. We make estimates of production cross sections of
these predicted resonances in ppbar collisions for PANDA at the forthcoming FAIR facilities.

Dr. Raquel Molina
IFIC (Valencia)

Prof. A. Ramos

18 Jan 2012

(507)

Nuclear Forces in Chiral EFT
Abstract
In recent years, there has been substantial progress in the derivation
of nuclear
forces from Chiral Effective Field Theory (EFT). Accurate twonucleon forces
has been constructed at nexttonexttonexttoleading order (N3LO) and
applied to nuclear few and many body systems. I will make a short
introduction
to Chiral EFT and show how nuclear forces emerges in this framework showing
some results. I will also give some remarks about multinucleon forces
and problems still open.

Dr. David R. Entem
U. Salamanca

Dr. B. JuliaDiaz

2011

21 Dec, 2011, 11:45

(507)

Seeing topological order with ultracold atoms
Abstract
Topological phases of matter are a field of increasing interest because of their potential technological applications ranging from sensitive detectors to quantum computation. Their observation has been up to now, however, limited to indirect measurements due to the nonlocal character of the corresponding order parameters. We have developed a general method to directly observe a topological phase with coldatom systems on optical lattices. I will first introduce the idea of topological order and then discuss our proposal to realize a characteristic topological model introduced by Haldane and how to detect it in setups of ultracold atoms confined in optical lattices.
E. Alba et al., Phys. Rev. Lett 107, 235301 (2011).

Dr. J. MurPetit
CSIC

Dr. B. JuliaDiaz

14 Dec, 2011, 11:45

(507)

Elementary excitations in homogeneous Neutron Star matter.
Abstract
The elementary excitations of superfluid matter below the crust of Neutron
Stars are relevan for many phenomena and properties, like neutrino mean
free path, heath capacity, thermal conductivity and others.
I will present a study of the spectral functions of these elementary
excitations. The theory is based on the conserving approximation scheme,
generalized to the superfluid case. We apply the method to the proton and
electron components, where both pairing and Coulomb interactions are
introduced. The interplay of these two interactions in determining the
overall structure of the spectrum and of the corresponding
strength functions is discussed in detail. I will discuss the apearence of
a pseudoGoldstone mode, characterized by a sharp peak in the strength
function, and whose velocity is determined by both Coulomb and pairing
interaction. This mode merges into the usual Goldstone mode when the
Coulomb interaction is switched off, i.e. in pure superfluid, where it is
a consequence of the breaking of gauge invariance. Also the branch
corresponding to the pairbreaking mode is clearly identified. The
pseudoGoldstone and the pairbreaking mode undergo a quasicrossing close
to twice the pairing gap Delta, above which, at increasing value of the
momentum, the upper pseudoGoldstone branch merges into the sound mode of
the normal fluid, while the lower pairbreaking mode corresponds to the
overdamped mode also present in the normal fluid. At increasing value of
the pairing gap the spectrum above 2*Delta shrinks and finally disappears
at large enough value of the gap. Besides these branches, the electron
plasmon appears at higher energy. Even at moderately values of the gap,
such as 100200 KeV, the electron plasmon mode actually disappears. The
nuclear particlehole interaction for the proton component is briefly
discussed and it is argued that its role is marginal.

Prof. M. Baldo
INFN, Catania

Prof. X. Vinyas

30 Nov, 2011, 11:45

(507)

Adsorption of classical and quantum fluids
on nanostructured substrates from atomistic simulations
Abstract
I will illustrate some recent applications of
computational methods (based on semiempirical and "ab initio"
Density Functional theory, and Grand Canonical Monte Carlo techniques)
to the adsorption of classical and quantum fluids
on substrates that are structured at the nanoscale.
An essential ingredient of such calculations is
the adatomsubstrate potential: the importance of
"ab initio" electronic structure calculations
in computing the van der Waals contribution to the
adatomsurface interactions will be discussed, which allow
to obtain more accurate and reliable physisorption
potentials.

Dr. F. Ancilotto
U. Padova

Dr. M. Pi

23 Nov, 2011, 11:45

(507)

Supersolidity in 4He: a Path Integral Monte Carlo study
Abstract
The existence of a supersolid state of matter, that is a phase characterized at the same time by crystalline order
and superfluidity, has been speculated for many decades. In the last years, the observation of non classical rotati
onal inertia effects in samples of solid $^4$He [1] has notably increased the interest in the topic of supersolidit
y. However, the interpretation of the experimental data is rather difficult and a model able to give an exhaustive
description of the supersolidity phenomenon is still lacking. From the theoretical point of view, Quantum Monte Car
lo techniques have been widely used in the microscopic study of quantum crystals. In particular, Path Integral Mont
e Carlo turns out to be one of the most powerful method in the study of solid $^4$He, providing an easy picture for
superfluidity in manybosons systems and giving exact results for the averages of the physical observables.
In this talk, I will discuss the quantum properties of solid $^4$He as obtained in Path Integral Monte Carlo simula
tions. After a short introduction of the physical system and of the computational technique, I will show results of
the BoseEinstein condensation and superfluidity properties of the solid sample, considering different microscopic
configurations of the $^4$He atoms: the perfect crystal, the crystal with vacancies and the amorphous solid. The m
ain objective of this study is to investigate which of these models provides results in better agreement with the e
xperimental measurements [2].
[1] Kim and Chan, Nature 425, 227 (2004).
[2] Rota and Boronat, arXiv:1110.3988 (2011).

Mr. R. Rota
UPC

Dr. A. Polls

16 Nov, 2011, 11:45

(507)

Semiclassical approach to pairing in finite Fermi systems:
nuclei, neutron stars and cold atoms
Abstract
Two issues are treated in this talk: (i) the generic fact that if a fermionic superfluid in the BCS regime overflows from a narrow container into a much wider one, pairing is much suppressed at the overflow point. Physical examples in cold atoms, neutron stars and nuclei where this feature may play an important role are discussed. (ii) A ThomasFermi (TF)
approach to inhomogeneous superfluid Fermisystems is presented and shown that it works well in cases where the Local Density Approximation (LDA) breaks down.

Prof. X. Viñas
ECM


9 Nov, 2011, 11:45

(507)

Ansatz for the manybody function in a harmonic trap: from few to many...
Abstract
Is it possible to reproduce and understand the properties of a manybody system by a generalization of the exact function of a single pair? How 'different' is 'more'? I develop an analytical manybody wave function to accurately describe the crossover of a onedimensional bosonic system from weak to strong interactions in a harmonic trap. The explicit wave function, which is based on the exact twobody states, consists of symmetric multiple products of the corresponding parabolic cylinder functions, and respects the analytically known limits of zero and infinite repulsion for arbitrary number of particles. For intermediate interaction strengths we demonstrate, that the energies, as well as the reduced densities of first and second order, are in excellent agreement with large scale numerical calculations.

Mr. I. Brouzos
ILP, Hamburg

Dr. B. JuliaDiaz

14 Oct, 2011, 11:45

(507)

Nuclear Physics from Lattice QCD
Abstract
Recent Lattice QCD techniques and results applied to Nuclear Physics
will be reviewed, including the extraction of twobody bound states.

Prof. Martin Savage
U. Washington

Prof. A. Parreño

5 Oct, 2011, 11:45

(507)

Comparative study of threenucleon potentials in nuclear matter
Abstract
A new generation of local threebody potentials providing an excellent description of the properties of light nuclei, as well as of the neutrondeuteron doublet scattering length, has been recently derived.
We have performed a comparative analysis of the equations of state of both pure neutron matter and symmetric nuclear matter obtained using these models of threenucleon forces. None of the considered potentials simultaneously explains the empirical equilibrium density and binding energy of symmetric nuclear matter. However, two of them provide reasonable values of the saturation
density. The ambiguity concerning the treatment of the contact term of the chiral inspired potentials is discussed.

Mr. Alessandro Lovato
SISSA, Italy

Dr. A. Polls

21 Sep, 2011, 11:45

(507)

Hyperons in massive neutron stars: test of hadronic physics at high densities
Abstract
The constituents of dense matter in neutron stars are still far from being understood. As strangeness is not conserved in weak interactions, and timescales associated with neutron stars are much greater than those associated with weak interactions, the conversion of nucleons to hyperons in the neutron star core is energetically favoured. The highest neutron star mass that can be supported depends crucially on its constituents; presence of additional degrees of freedom such as hyperons above nuclear saturation density results in a softer EoS and a smaller maximum mass neutron star. A neutron star containing hyperons in its interior cannot be more massive than about 1.8 M⊙ according to existing models. Recently, Shapiro delay measurements from radio timing observations of a binary millisecond pulsar indicated a mass of 1.97 ± 0.04 M⊙ of the neutron star. Such measurements of large neutron star masses provide strong constraints on the presence of hyperons. It is to be investigated whether the nonexistence of hyperons in massive neutron stars is an artifact of our limited understanding of the behaviour of hadrons at high densities.

Dr. Debarati Chatterjee
University of Heidelberg, Germany

Dr. L. Tolos

05 Jul, 2011, 11:45

(507)

Injection of atoms and molecules into a freestanding
superfluid helium fountain
Abstract
Copper atoms and Cu2 molecules are produced by laser ablation in a cold helium gas at 1.7
K and their spatial and frequency domain visualization was carried out by using the laser
induced fluorescence technique. Due to collisions in the cold buffer gas, Cu/Cu2 thermalize
effectively within 1 ms of their creation, after which their spatial distribution expands slowly
due to thermal diffusion. A 200 micrometer diameter superfluid helium fountain is operated within
1 mm distance from the ablation target and the interaction of Cu/Cu2 with the fountain is
characterized. The spatial images show that Cu atoms pileup in front of the fountain and a
deficit of Cu atoms develops behind the fountain. Cu2 on the other hand accumulates in the
fountain. The deficit exceeds the pileup in the front indicating an additional loss channel
for Cu atoms. Ab initio electronic structure calculations were carried out to characterize
the CuHe interaction giving an estimate for the binding energy, 6.6 K. Cu2 interaction is
about twice as deep. Timeindependent bosonic density functional theory (DFT) predicts
that Cu is heliophobic and Cu2 heliophilic. By using the timedependent formalism, it was
established that the thermal kinetic energy of classical Cu atoms is not sufficiently high for
penetrating the fountain whereas Cu2 penetrate the fountain. The calculations demonstrate
that the atoms accelerate significantly near the fountain surface due to the Cu/Cu_2 H en
attraction. The atom/molecule looses all of its kinetic energy at the fountain surface through
a multiphonon process and finally localizes at the fountain surface.

Dr. Jussi Eloranta
Department of Chemistry and Biochemistry, California State University

Dr. M. Pi

29 Jun, 2011, 11:45

(507)

Symmetry energy effects in finite nuclei and nuclear matter
Abstract
The symmetry energy and its density dependence play an important
role to understand the structure of systems as diverse as atomic nucleus and
the neutron star. In this talk, the effect of symmetry energy constrained from
the measured neutron skin thickness of finite nuclei on neutron star properties
and liquid gas phase transition in hot asymmetric nuclear matter, using relativistic
mean field (RMF) model will be discussed.

Dr. Bharat Sharma
ECM

Dr. X. Viñas

31 May, 2011

(507)

Warm alphanucleon matter
Abstract
Properties of warm dilute alphanucleon matter are studied
in a variational approach in the ThomasFermi approximation, starting from
an effective nucleonnucleon interaction. The equation of state of such a
matter, its symmetry energy and incompressibility are calculated and
compared to those obtained from the modelindependent Smatrix approach.

Prof. J. N. De
Saha Institute of Nuclear Physics, Kolkata, India

Dr. X. Viñas

30 May, 2011

(507)

A multiscale computational method to simulate flow of fluids with a memory effect
Abstract
We present a multiscale computational method to simulate flow of fluid systems with a large spatial extent. We simulate small parts of the system using molecular dynamics, and only occasionally pass information among these parts based on a continuum fluid mechanics framework. This method does not rely on any constitutive equation, and hence is wellsuited for a fluid the flow of which suffers from memoryeffects. In addition, the simulation scheme can be parallelized in the sense that the molecular dynamics simulations of the different parts of the system can be performed on several individual computers.

Prof. S. De
Indiana University Southeast

Dr. X. Viñas

25 May, 2011

(507)

A century of nuclear physics ... and beyond!
Abstract
In May 1911, Rutherford postulated his atomic model based on the
GeigerMardsen experiment.
At the center of the atom, a new physical system was born: the atomic
nucleus. This marked the
birth of a new discipline, nuclear physics, that bloomed shortly after
its inception and had a major
historical impact. In this talk, I will briefly comment on the history
of nuclear physics, discuss some
of its applications, and, most of all, emphasize the future
perspectives of nuclear theory and
experiments in the XXIst Century.

Dr. Arnau Rios
U. Surrey

Dr. B. JuliaDiaz

18 May, 2011

(507)

The nuclear Yukawa model on a lattice
Abstract
We present the results of the quantum field theory approach to the nuclear Yukawa model
obtained by standard lattice techniques. We have considered the simplest case of two identical fermions
interacting via a scalar meson exchange. Calculations have been performed using Wilson fermions in the
quenched approximation. We found the existence of a critical coupling constant above which the model
cannot be numerically solved. The range of the accessible coupling constants is below the threshold value
for producing twobody bound states. Twobody scattering lengths have been obtained and compared to
the nonrelativistic results.

Prof. Jaume Carbonell
LPSC, Grenoble

Dr. J. Soto

6 Abril 2011

(507)

Bound states in Lattice QCD. The Hdibaryon
Abstract
I will discuss recent results of baryonbaryon interactions at low energies obtained by the NPLQCD Collaboration, at a pion mass of ~ 390 MeV, with a lattice volume of L ~ 2.5 fm and a lattice spacing of ~ 0.123 fm. Studying the volume dependence of our simulations performed at four different volumes, L ~ 2.0, 2.5, 3.0 and 3.9 fm, I will present evidence for a bound I=0, J=0, s=2 state (the Hdibaryon) , as well as, present constraints for its existence at the physical pion mass.

Dr. Assumpta Parreño
ECM


29 Mar 2011

(507)

Dynamical symmetry breaking in dualcore nonlinear systems
Abstract
Fundamental models of various physical media based on configurations with two parallel cores (waveguides) amount to systems of linearly coupled equations. A known example is the model of dualcore optical fibers or planar waveguides, which amounts a system of coupled nonlinear Schroedinger (NLS) equations. In such systems, obvious symmetric soliton solutions lose their stability through symmetrybreaking bifurcations, when the energy exceeds a certain critical value. The bifurcations simultaneously gives rise to stable asymmetric solitons. The talk aims to present an overview of basic models, results, and physical applications of the symmetrybreaking phenomena in conservative and dissipative nonlinear media.

Prof. Boris Malomed
Tel Aviv University

Dr. B. JuliaDiaz

23 Mar 2011, 11:45

(507)

Quantum simulations of thermodynamic and kinetic properties
of strongly coupled electromagnetic and quarkgluon plasmas.
Abstract
Determining the properties of strongly coupled hydrogen, electron – hole or quark – gluon plasmas is one of the main challenges of stronginteraction physics. We propose a stochastic simulations of thermodynamic and kinetic properties of the strongly correlated Coulomb systems in a wide range of temperature, density and quasiparticle masses. We use the direct quantum path integral Monte Carlo method (PIMC) developed for finite temperature within Feynman formulation of quantum mechanics to do calculations of internal energy, pressure and pair correlation functions.

Dr. Vladimir Filinov
JIHT


2
Feb 2011, 11:45 
(507)

Muonic hydrogen at finite temperature with of nonrelativistic effective field theories
Abstract
At high temperatures QCD undergoes a phase transition into the so called quarkgluon plasma (QGP). At temperatures above this phase transition heavy quarkonium (HQ) states melt, and it has been proposed that the disappearance of different HQ states can be used as a thermometer for heavyion collisions at accelerators that try to create the QGP experimentally. However, our current understanding of HQ at finite
temperature still does not allow to do this in a reliable way. Muonic hydrogen shares a number of properties with HQ that make the study of
muonic hydrogen at finite temperature a very good toy model for understanding HQ. In addition it is nowadays produced in large
samples and hence the finite temperature effects on it may also be measured experimentally.
In this talk I will review nonrelativistic effective field theories and the way how they are able to easily conect QCD with potentials models. Next I will use these techniques to study muonic hydrogen at finite temperature and I will also comment their application to HQ.

Mr. Miguel Angel Escobedo
ECM

Dr. J. Soto

19
Jan 2011, 11:45 
(507)

Anomalous isentropic effects in ultracold attractively interacting fermions loaded into an optical lattice
Abstract
Dilute atomic gases cooled down to quantum degeneracy constitute an exceptional toolbox to investigate quantum manybody phenomena. In this sense, the high control and tunability achieved in ultracold gases loaded into an optical lattice a standing wave created by interfering two counterpropagating laser beams acting on the atoms as a spatially periodic potential turn them into promising candidates to simulate manybody systems in the strongly correlated regime.\\
In this regime the correlations existing between particles are revealed not only in the ground state and lowlying excitations but also they can be manifested as counterintuitive thermodynamic effects. We have studied theoretically an ultracold mixture of attractively interacting fermionic atoms loaded into an optical lattice at finite entropy. In this system a redistribution of the entropy leads to an anomalous expansion of the cloud when adiabatically increasing the attractive interaction, as a consequence of the enhancement of pairing between particles. This effect has been observed experimentally in qualitative agreement with the theoretical analysis [1].\\
In this talk, I will briefly introduce how optical lattices are experimentally realized and the model used to describe these systems (the celebrated Hubbard model). Next I will focus on the different approaches we have performed to analyze theoretically the thermodynamics of the fermionic mixture in the presence of the lattice.\\
[1] L. Hackermüller, U. Schneider, M. MorenoCardoner, T. Kitagawa, Th. Best, S. Will, E. Demler, E. Altman, I. Bloch, and B. Paredes, Science \bf 327 \rm, 1621 (2010)

Ms. Maria MorenoCardoner
U. Munich

Dr. B. JuliaDiaz

2010

21
Dec 2010, 11:45 
(507)

Boltzmann equation for the collective modes of cold trapped Fermi gases
Abstract
In this seminar I will talk about three methods to solve the Boltzmann
equation: the method of averages, the moments method and the testparticle
method. The first two are widely used semianalytical methods, whereas the latter
is a numerical one that has been traditionally used in nuclear physics to simulate
heavyion collisions, but is rarely used for cold trapped atoms.
I will discuss some results obtained with these methods for the collective modes in
trapped Fermi gases at finite temperature and in the normal fluid phase.
In particular, I will present two studies:
the dipole oscillations in multicomponent fermionic mixtures via the averages
method and the comparison between moments and numerical method for the
quadrupole mode in a twocomponent mixture. This comparison
shows that the moments method at lowest order (that is the commonly used one)
gives qualitatively good results. However, it is necessary to go beyond the lowest
order approach to obtain quantitatively reliable predictions for modes, as the
quadrupole mode, that are sensitive to spatial nonhomogeneities.
 Dr. Silvia Chiacchiera
Centro de Fisica Computacional, U. Coimbra

Dr. B. JuliaDiaz

15
Dec 2010, 11:45 
(507)

DN interaction from meson exchange
Abstract
A model of the DN interaction is developed in close analogy to the mesonexchange $\bar KN$
potential of the Juelich group utilizing SU(4) symmetry constraints. The main ingredients of the interaction are provided by vector meson exchange and higherorder box diagrams. The coupling of $DN$ to the $\pi\Lambda_c$ and $\pi\Sigma_c$ channels is taken into account. The interaction model generates the $\Lambda_c$(2595) resonance dynamically as a $DN$ quasibound state. Results for $DN$ total and differential cross sections are presented and compared with predictions of two interaction models that
are based on the leadingorder WeinbergTomozawa term. Some features of the $\Lambda_c$(2595)$ resonance are discussed and the role of the nearby $\pi\Sigma_c$ threshold is emphasized.
Selected predictions of the original $\bar KN$ model are reported too. Specifically, it is pointed out that the model generates two poles in the partial wave corresponding to the $\Lambda$(1405) resonance.

Dr. Laura Tolós
Institut de Ciències de l'Espai

Dr. B. JuliaDiaz

24
Nov 2010, 11:45 
(507)

Dressing manybody lattice systems of ultracold atoms by shaking
Abstract
Strong timeperiodic potential modulations (beyond the regime of linear
response) can be a robust and powerful tool for the manipulation of manybody systems as they are realized experimentally with ultracold atoms. Such novel control schemes are reminiscent of manipulating internal atomic or molecular degrees of freedom by means of coherent radiation. We describe them theoretically by an approach similar to the dressed atom picture, taking into account the possibly strong interaction between the particles [13]. A striking example is given by a recent experiment (proposed in [1]): In a system of bosonic atoms in an optical lattice the transition from a superfluid to a Mottinsulator (and back) has been induced by smoothly switching on (and off again) the amplitude of a timeperiodic acceleration of the whole lattice
potential [4]. This phenomenon relies on a complex dynamics being a combination of both diabatic and adiabatic following of manybody Floquet states [1,3]. In a recent proposal, we suggest to induce a sign change of the hopping matrix elements in a system of repulsively interacting bosons in a triangular lattice. The sign change can be achieved by dressing the system with a fast elliptical lattice acceleration [5]. The system then behaves as a frustrated antiferromagnet  a classical one in the limit of weak interaction and a quantum antiferromagnet (with large coupling matrix elements on the order of the boson hopping) in the limit of hardcore bosons. For the latter, N\'eelordered (spiral or staggered) superfuid phases and gapped spinliquid phases are predicted [56].
[1] A. Eckardt, C. Weiss, and M. Holthaus, "SuperfluidInsulator Transition in a Periodically Driven Optical Lattice",
Phys. Rev. Lett. 95, 260404 (2005)
[2] A. Eckardt and M. Holthaus, "ACinduced superfluidity",
EPL 80, 50004 (2007)
[3] A. Eckardt and M. Holthaus, "Avoided level crossing spectroscopy with dressed matter waves", Phys. Rev. Lett. 101, 245302 (2008)
[4] A. Zenesini, H. Lignier, D. Ciampini, O. Morsch, and
E. Arimondo, "Coherent Control of Dressed Matter Waves",
Phys. Rev. Lett. 102, 100403 (2009)
[5] A. Eckardt, P. Hauke, P. SoltanPanahi, C. Becker,
K. Sengstock, and M. Lewenstein, "Frustrated quantum antiferromagnetism with ultracold bosons in a triangular lattice",
EPL 89, 10010 (2010).
[6] R. Schmied, T. Roscilde, V. Murg, D. Porras, and J. I. Cirac, "Quantum phases of trapped ions in an optical lattice", New J. Phys. 10, 045017 (2008)

Dr. Andre Eckardt
ICFO

Dr. B. JuliaDiaz

17
Nov 2010, 11:45 
(507)

Dipolar condensates in a toroidal trap
Abstract
In contrast to usual alkali BoseEinstein condensates, where the swave
contact interaction is dominant, dipolar condensates show a new kind of
interaction: the dipolar interaction, which is anisotropic, nonlocal and
longrange. We will show that when such a condensate is confined in a
toroidal trap, the anisotropic character of the interaction is enhanced
and the condensate shows an azimuthal density distribution depending on
the relative strength of the two interactions. For small scattering
lengths, this density distribution resembles that of a condensate in a
ringshaped doublewell potential, but now the potential barrier
separating the two wells is selfinduced by the dipolar interaction.
Although the density is not uniform along the torus, the system admits
vortex states and persistent currents. In addition, the selfinduced
double well is capable of sustaining Josephson oscillations, as well as a
selftrapping regime.

Ms. Marta Abad Garcia
ECM


27
Oct 2010, 11:45 
(507)

Evolution of the excited electron bubble in
liquidhelium and the appearance of fissionlike processes
Abstract
When an electron is injected into liquidhelium, it
forces open a cavity from which the helium atoms are
excluded. The electron can then be photoexcited to a 1P state,
triggering a dynamical process in which the surrounding
helium atoms adapt to the excited electron wavefunction.
We have studied the evolution of an excited electron bubble
in superﬂuid helium and found that the relaxation path it follows
strongly depends on pressure. While for pressures below 1 bar
the electron bubble can radiatively decay to a deformed metastable
state and then relax to the spherical ground state, we have found that
above 1 bar the bubble splits in two distinct
baby bubbles in the course of the dynamical evolution, pointing to
a different relaxation path in which the electron may be
localized in one of the baby bubbles while the other collapses,
allowing for a pure radiationless deexcitation.
The dynamics of the electron bubble has been computed within a
density functional approach for liquidhelium and an
adiabatic aproximation for the electron evolution. Results for
the evolution of the excitated 2P electron, in which the adiabatic
approximaion breaks at an early stage of the evolution,will be also shown.

Mr. David Mateo
ECM


20
Oct 2010, 11:45 
(507)

Superconducting quantum circuits:
Quantum information and circuit quantum electrodynamics
Abstract
Quantum effects in superconducting circuits have been a focus of intense study in the past years. Progress has been made to couple several qubits to each other and to perform quantum gates between them. Coupling to onchip superconducting resonators has also been achieved. This has opened the possibility to couple remote qubits using the resonator, and it has allowed studying the qubitphoton interaction to regimes of parameters unattainable in experiments in the field of cavity quantum electrodynamics (QED) in quantum optics.
In this talk I will present the superconducting flux qubit in the context of circuit QED. First the coherent coupling of a flux qubit and an LC resonator will be described. In the second part of the talk a system consisting in another flux qubit very strongly coupled to a resonator will be presented, and the observation of effects beyond the rotating wave approximation in the Jaynes Cummings model in this system will be shown.

Dr. Pol Forn Diaz
Delft University of Technology

Mr. J.M. Escartin

13
Oct 2010, 11:45 
(507)

Ultraintense laser opportunities
Abstract
"Laser light" and "ionizing radiation" are traditionally completely unconnected concepts. However, in the early 80’s Tajima and Dawson predicted theoretically that electrons can be accelerated in plasmas generated by ultraintense laser pulses. The later development of the Chirped Pulse Amplification (CPA) technique allowed Tajima's prediction becoming a reality. In our days, electrons, as well other particles like protons, can be accelerated using lasers. Monochromatic electron beams of 100 MeV [and 1pC charge] have been already produced. Moreover, reaching 1 GeV electron energies is now also possible. These facts open the door to the design of a new class of laserbased accelerators, which represent major prospect of improvement in accelerators technologies (much shorter accelerations distances, more compact equipments, high charge beams, etc.).
In this talk, we will introduce the Centro de Láseres Pulsados (CLPU), at Salamanca, where shortly these ultraintense lasers will be installed, allowing the Spanish scientific community having access to nuclear laser physics, lasermatter interactions physics, and laserbased accelerator technology.

Dr. David Bote Paz
University of Salamanca

Dr. B. JuliaDiaz

5
Oct 2010, 10:00 
(507)

An efficient realspace density
functional algorithm
Abstract

Prof. Eckhard Krotscheck
Linz University

Dr. M. Barranco

15
Sep 2010, 11:45 
(505)

Microscopic Approach to Nucleon Spectra in Hypernuclear
NonMesonic Weak Decay
Abstract
A consistent microscopic diagrammatic approach is applied for the first
time to the calculation of the nucleon emission spectra in the
nonmesonic weak decay of $\Lambda$hypernuclei. We adopt a nuclear
matter formalism extended to finite nuclei via the local density
approximation, a onemeson exchange weak transition potential including
the exchange of the complete octets of pseudoscalar and vector mesons and
a Bonn nucleonnucleon strong potential. Ground state correlations and
final state interactions, at second order in the nucleonnucleon
interaction, are introduced on the same footing for all the isospin
channels of one and two nucleon induced decays. Single and
doublecoincidence nucleon spectra are predicted for $^{12}_{\Lambda}$C
and compared with recent KEK and FINUDA data. The key role layed by
quantum interference terms allows us to improve Discrepancies with data
remain for proton emission.

Dr. Eduardo Bauer
Universidad Nacional de La Plata and IFLP CONICET

Dr. A. Parreño

30
Jun 2010, 15:00 
(507)

Electromagnetic polarisabilities in lattice QCD
Abstract
Electromagnetic and spin polarisabilities are important in describing the quasistatic
response of hadrons to the presence of of external electromagnetic fields. I will report on
recent progress in determining electric polarisabilities and magnetic moments of both
charged and neutral hadrons using lattice techniques.

Dr. William Detmold
College of William & Mary / Jefferson Lab

Dr. A. Parreño

28/29
Jun 2010, 11:30 
(507)

Bosonic Josephson Junctions
Abstract
Bosonic Josephson Junctions:
In the two lecture I will give an overview of the experimental work on
bosonic Josephson junctions in Heidelberg and put it in context with
related
work. After the detailed introduction of the experimental tools allowing
the
realization of internal and external bosonic Josephson junctions, I will
discuss in the first part of the lecture series in detail the meanfield
dynamics. In the second part the quantum description in the framework of
two
mode Bose Hubbard model will be presented and corresponding experimental
results discussed.
1) The steps towards experiments with ultracold gases
a) Generation of ultracold gases in two mode situations
b) How to look at the atoms at atom shot noise level
2) Meanfield limit of N Particles  external and internal bosonic
Josephson
junction
a) Meanfield description
a) Dynamics  from Rabi to Josephson physics
b) Thermal Equilibrium properties  Phase noise thermometry
3) Beyond meanfield
a) Quantum Dimer, Two mode Bose Hubbard, LipkinMeshkovGlick
Hamiltonian
b) Squeezing  adiabatic, diabatic
c) Quantum Metrology  atom interferometry beyond classical
precision limit


Prof. Markus Oberthaler
U. Heidelberg

Dr. M. Guilleumas

16
Jun 2010, 11:45 
(507)

Symmetry energy, neutron star crust and neutron star thickness
Abstract
We perform a systematic analysis of the density dependence of nuclear symmetry energy within the microscopic BruecknerHartreeFock (BHF) approach using
the realistic Argonne V18 nucleonnucleon potential plus a phenomenological threebody force of Urbana type. Our results are compared thoroughly with those arising from several Skyrme and relativistic effective models. The values of the parameters characterizing the BHF equation of state of isospin asymmetric nuclear matter fall within the trends predicted by those models and are compatible with recent constraints coming from heavy ion collisions, giant monopole resonances, or isobaric analog states. In particular we find a value of the slope parameter L=66.5 MeV, compatible with recent experimental constraints from isospin
diffusion, L=88±25 MeV. The correlation between the neutron skin thickness of neutronrich isotopes and the slope L and curvature Ksym parameters of the symmetry energy is studied. Our BHF results are in very good agreement with the correlations already predicted by other authors using nonrelativistic and relativistic effective models. The correlations of these two parameters and the neutron skin thickness with the transition density from nonuniform to ?stable matter in neutron stars are also analyzed. Our results confirm that there is an inverse correlation between the neutron skin thickness and the transition density.

Dr. Isaac Vidaña
U. Coimbra

Dr. A. Polls

15
Jun 2010, 11:45 
(507)

Nuclear symmetry energy deduced
from dipole excitations: a comparision with other constraints
Abstract
In this seminar, we briefly review the amount of
general information concerning the nucleonnucleon interaction
and the nuclear equation of state (EOS) that has been extracted
from giant resonances. We then focus on one of the most
debated questions at present, namely the density dependence
of the nuclear symmetry energy. We have investigated correlations
between the parameters governing the symmetry energy, the neutron
skins, and the percentage of energyweighted sum rule
(EWSR) exhausted by the Pygmy Dipole Resonance (PDR) in $^{68}$Ni
and $^{132}$Sn. These correlations are found within different
Random Phase Approximation (RPA) models for the dipole response, based on
both a representative set of Skyrme effective forces and also mesonexchange
effective Lagrangians. We show that the comparison with the experimental
data has
allowed to constrain the value of the derivative of the symmetry
energy at saturation. We finally compare this constrain with
the findings of quite different methods.

Prof. Gianluca Colo
INFN Milano

Dr. X. Vinyas

711
Jun 2010, 11:13: 
(505)

(CURSO) Chiral Effective Theory for Electromagnetic Interactions with Light Nuclei
Abstract
Day 1: Introduction to Effective Field Theory (EFT)
Discussion of EFT as a general principle.
Examples from Classical Electrodynamics (Multipole expansion, Thomson scattering). Examples from Quantum Field Theory (Fermi electroweak theory, phi4 theory in six dimesions).
Day 2: Chiral Symmetry and hadronhadron interactions
Chiral symmetry of QCD and the hidden nature of chiral symmetry in lowenergy hadronhadron interactions.
Goldstone bosons.
Chiral perturbation theory (ChiPT) as the lowenergy EFT of QCD.
ChiPT with baryons.
ChiPT predictions for nucleonnucleon (NN) interactions.
Day 3: Why and how we iterate
The problem with perturbative calculations of the NN amplitude.
The LippmannSchwinger equation and how to solve it.
ChiPT calculation of the leadingorder NN potential.
Renormalization of the leadingorder potential.
Subleading potentials.
Predictions for NN and NNN scattering.
Issues regarding renormalization.
Day 4: Electron scattering from light nuclei
ChiPT predictions for nucleon electromagnetic form factors.
Introduction to electrondeuteron scattering.
Predictions for deuteron electromagnetic form factors in chiral effective theory.
Form factors for the trinucleons and electroninduced breakup of the deuterium nucleus.
Day 5: Compton scattering from light nuclei
Introduction to Compton scattering on the proton and neutron; overview of proton Compton experiments.
ChiPT predictions for Compton scattering from the proton.
ChiPT predictions for Compton scattering from the deuteron.
Comparison with data.
Issue associated with the nuclear bound state.
ChiPT predictions for Compton scattering from Helium3.
Compton scattering outlook.

Dr. Daniel Phillips
Ohio University

Dr. A. Parreño

1922
Apr 2010 
(507)

(CURSO, MASTER PHOTONICS) Light induced control of cold atoms
Abstract
COURSE CONTENTS:
1. Maxwell’s demon
2. The atom diode
3. The magic mirror: stopping and cooling particles by moving barriers
4. Shortcut to adiabaticity
5. Time and clocks
6. Atomic clocks, interferometers and cold atoms
7. Arrival times and atomic fluorescence
8. Trapped ions in metrology and quantum information
9. Einstein beyond E=mc2
10. Zeno effect

Prof. J. G. Muga
U. Pais Vasco

Dr. J. Martorell

7
Apr 2010, 11:45 
(507)

NucleonNucleon Interactions from the Quark Model
Abstract
We report on investigations of the applicability of nonrelativistic
constituent quark models to the lowenergy nucleonnucleon (NN)
interaction. The major innovations of the resulting NN potential are
the use of the $^3$P$_0$ decay model and quark model wave functions to
derive nucleonnucleonmeson formfactors, and the use of a colored
spinspin contact hyperfine repulsive core rather than the heavy meson
exchange mechanism used in the meson exchange theory of nuclear
forces. We assess the ability and limitations of the model to
reproduce experimental free NN scattering phase shifts and $^1$S$_0$
scattering lengths and effective ranges. We also present the nuclear
matter Equation of State in the BruecknerHartreeFock approximation
for the potential. Theoretical implications and plans for future
study are discussed.

Dr. Clark Downum
ECM

Dr. J. Soto

17
Mar 2010, 11:45 
(507)

The magic of getting peaks with cuts in experiments: An explanation
for the "Theta+ pentaquark" peak.
Abstract
We present a calculation of the $\gamma d \to K^+ K^ n p $ reaction with the aim of seeing if the experimental peak observed in the $K^+ n$ invariant mass around 1526 MeV, from where evidence for the existence of the $\Theta^+$ has been claimed, can be obtained without this resonance as a consequence of the particular dynamics of the process and the cuts applied in the experimental set up. We find that a combination of facts leads indeed to a peak around 1530 MeV for the invariant mass of $K^+ n$ without the need to invoke any new resonance around this energy. This, together with statistical fluctuations that we prove to be large with the statistics of the experiment, is likely to produce the narrower peak observed there.

Prof. Eulogio Oset
Universidad de Valencia

Dr. A. Ramos

11
Mar 2010, 11:45 
(505)

Neutron Star Structure with Hyperons and Quarks
Abstract
The highdensity nuclear equation of state within the BruecknerHartreeFock
approach is discussed. Particular attention is paid to the effects of
nucleonic threebody forces, the presence of hyperons, and the joining
with an eventual quark matter phase.
The resulting properties of neutron stars, in particular the
massradius relation, are determined. It turns out that in our
approach the maximum mass is about 1.7 solar masses and that stars
heavier than about 1.4 solar masses contain necessarily quark matter.

Dr. HansJosef Schulze
INFN Catania Italia

Dr. A. Polls

27
Jan 2010, 11:45 
(507)

Radial distributions in heavylight mesons and $B^0$$\bar B^0$ mixing amplitude in the static limit.
Abstract
Phenomenology of the heavylight mesons is investigated by using QCD simulations on the lattice 
in particular, the light quark dynamics when the heavy quark is infinitely heavy.
We present a new method which allows for the first lattice determination of
the pion emission in the transition between the first excited and the lowest lying heavylight meson.
High accuracy results for coupling to pions also obtained through improvements over previous lattice calculations.
These couplings are necessary ingredients for
the description of heavylight mesons by an effective theory known as the Heavy Meson Chiral Perturbation Theory.
They are also essential in the chiral extrapolations of the lattice results for the quantities relevant
to the $B$physics phenomenology.
We then make a detailed study of the matrix elements of all parity conserving fourquark $\Delta B=2$
operators which enter the theoretical description of the $B^0$$\bar B^0$ mixing amplitude in the Standard Model,
and in its supersymmetric extensions.
This is the first such study in fully unquenched lattice QCD. With an improved static quark propagator,
the spurious mixing of operators computed on the lattice is much smaller with
respect to what has been done in the past.
We close with a short discussion of impact of the results on the $B$physics phenomenology.

Dr. Emmanuel Chang
U. Barcelona


2009

22
Dec 2009, 11:45 
(507)

Mixtures of Bose gases confined in concentrically coupled toroidal traps
Abstract
A twocomponent BoseEinstein condensate confined in an axiallysymmetric potential with two local minima,
resembling two concentric toroidal traps, is investigated. The system shows a number of quantum phase transitions
that result from the competition between phase coexistence, and radial/azimuthal phase separation. The groundstate
phase diagram, as well as the rotational properties, including the (meta)stability of currents in this system, are analyzed.

Dr. Francesc Malet
U. Lund

Dr. M. Barranco

21
Dec 2009, 11:45 
(507)

A guided tour in Non Equilibrium Green functions and an application to strongly correlated Hubbard systems
Abstract
In this talk I will give an introduction of the timedependent KadanoffBaym equations (KBE), which are a cornerstone in microscopic theory of nonequilibrium quantum processes. We
have recently solved the KBE for a Hubbard chain within different manybody approximations (HartreeFock, 2$^{nd}$ Born, GW and Tmatrix approximations) and the results are compared to those of the exact solution.
Benchmarking approximate results against exact ones allows us to address two rather fundamental issues in the non equilibrium dynamics of strongly correlated systems. I) A characterization of the performance of several standard MBAs in the nonequilibrium regime. Having a definite notion of how good a specific MBA can be is highly relevant to its application to cases
(typically, infinite systems) where exact solutions are not available. Our results show that the Tmatrix approximation is overall superior to the other MBAs, at all electron densities. II) A scrutiny of the whole idea of Many Body Perturbation Theory in the KadanoffBaym sense, when applied to finite systems. The surprising outcome of our study is that during the time evolution, the KBE develop an unphysical steady state solution. This is a genuinely novel feature of the timedependent KBE, i.e. is not inherited from possible limitations/approximations in the calculation
of the initial state. Our extensive numerical characterization gives robust evidence that the problem occurs in general, whenever MBPT is applied to finite systems, and approximate self energies based upon infinite partial summations are used.
In the end I will briefly discuss the work in progress and some future directions.

Marc Puig von Friesen
U. Lund

Dr. A. Polls

16
Dec 2009, 11:45 
(507)

Isospin breaking effects in the dynamically generated X(3872) resonance.
Abstract
We have studied isospin breaking effects in the X(3872) resonance and
found a natural explanation for the branching fraction of the X
decaying to Jpsi with two and three pions being close to unit. Within
our framework the X(3872) is a dynamically generated resonance in
coupled channels. The simultaneous investigation of the X decay to D^0
Dbar^*0 and Jpsi pi pi shows that the preferred structure for the X is
a slightly unbound, virtual state of D\bar D^* and D^* \bar D. We also
comment on the relationship between wave functions and couplings for
bound states, and apply it for the X(3872).

Mr. Daniel Gamermann,
IFICU. Valencia

Dr. A. Ramos

4
Nov 2009, 11:45 
(507)

Heaviest nuclei
Abstract
The production of new superheavy nuclei (Z>108)
through heavy ion reactions of actinides with 48Ca
is explained. The decays of these new elements are
analyzed and their stability properties are discussed.
Predictions of new magic numbers beyond N=126 and Z=82
are also given.

Prof. Yu. Oganesyan (JINR, DUBNA)
JINRDUBNA

Dr. X. Vinyes

28
Oct 2009, 11:45 
(507)

Excitation spectra of small paraHydrogen clusters
Abstract
Small (pH2)N clusters have been produced in a cryogenic free jet expansion
and studied by Raman spectroscopy. Clusters with N=28 molecules have been
unambiguously identified, and broad maxima were observed at N#13, 33, and
perhaps 55, indicating the existence of magic sizes related to geometric
shells. Quantum Monte Carlo methods have been used in recent years as a
theoretical tool to study (pH2)N clusters. Both diffusion Monte Carlo
(DMC) and path integral Monte Carlo (PIMC) calculations show that these
clusters exhibit a clear structural order, with the molecules occupying
concentric spherical shells, which could be related to some polyhedral
arrangement. Whereas up to N#22 these calculations are substantially in
agreement, for heavier clusters there are noticeable differences between
DMC and PIMC magic sizes. We present here DMC simulations for clusters
with N=340. The energies of all stabilized excitations with angular
momentum from L=1 to 13 have been calculated, as well as those of the
first L=0 vibrational excited state. Parahydrogen clusters exhibit very
rich spectra and no regular pattern can been guessed in terms of the
angular momenta and the size of the cluster, at variance with the situation
found for helium droplets. The partition function has been calculated from
the excitation spectra, thus allowing for an estimate of finite
temperature effects. An enhanced production is predicted for cluster sizes
N=13, 26, 31 and 36, at any temperature, and also for N=19, 29 and 34 at
some specific temperatures. The DMC and PIMC differences in the predicted
magic sizes are thus explained as being mostly due to thermal effects.

Prof. J. Navarro
CSICU. Valencia

Dr. M. Pi

23
Sep 2009, 11:45 
(507)

Spin and charge excitations
in multielectron QDs: the strongly correlated regime
Abstract
Correlation among particles in finite quantum systems leads to
complex behaviour and novel states of matter. Semiconductor quantum dots
containing a few excess electrons (electron molecule) are a protoype
system in this respect, whereby fewbody correlations beyond meanfield
effects can be obtained by detailed spectroscopy of their charge and spin
excitations.
In this seminar I will discuss our recent theoretical studies of charge
and spin excitations in strongly correlated quantum dots, in connection
with recent experiments, with focus on two specific aspects: 1) the
development of molecular excitations of the Wigner type in lowdensity
quantum dots; 2) the magnetic field dependence of the spin excitation
relaxation time.

Prof. Guido Goldoni
University of Modena and Reggio
Emilia

Dr. M. Pi

16
Jul 2009, 11:45 
(507) 
Through a phase transition in ion chains
Abstract
We propose an experiment to test the production of topological defects
following the KibbleZurek mechanism on trapped ions. Ions in a
harmonic trap undergo a structural secondorder phase t
ransition when a threshold ratio between the axial and transverse
frequency of the trap is crossed. Under weakening of the transverse
confinement, the system evolves
from a high symmetry phase (linear chain) to a doublydegenerated
groundstate manifold (zigzag chains), with the possible formation of
topological defects (kinks, an
tikinks, breathers). The density of defects is shown to obey the
scaling predicted by the Kibble Zurek mechanism in different
configurations amenable to experimental realization 
Dr.
A. del Campo
Imperial College (London)

Dr. N. Barberan 
02
Sep 2009, 11:45 
(507) 
Timedependent Green's functions description of nuclear
meanfield dynamics
Abstract
The timedependent Green's functions formalism allows for a consistent
description of the time evolution of quantum manybody systems within
the meanfield approximation or within more sophisticated correlated
approaches. An attempt to apply this formalism to the meanfield
dynamics of symmetric reactions for onedimensional nuclear slabs will
be discussed. Particular attention will be paid to the offdiagonal
elements of the Green's functions and their effect on the time
evolution. The importance of these will be quantified via a
superoperator cutoff field technique and their relevance for the
global time evolution as well as for time reversibility will be
assessed. The impact of offdiagonal elements in the associated Wigner
distributions will be briefly discussed. 
Dr.
A. Rios
University of Surrey

Dr. A. Polls 
20
Jul 2009, 11:45 
(507) 
Entanglement
production with trapped Bose atoms.
Abstract BoseEinstein condensate in a deep insulating optical
lattice is considered. Each lattice site contains many Bosecondensed
atoms. By resonance modulation of the trapping lattice field, it is
possible to create in each lattice site coherent topological modes
corresponding to nongroundstate condensates. These modes demonstrate a
rich variety of properties: dynamic phase transitions, squeezing, and
entanglement. The dynamics of the modes can be regulated by means of
external fields. 
Prof.
V.I. Yukalov 
Dr.
M Guilleumas 