SEMINARIS INTERNS FT/UB (2008-2009)


  • Title: "Extracting chiral low-energy couplings from lattice QCD"


           Speaker:Pilar Hernández (U. Valčncia)
           Date: Divendres 21-novembre-2008; 12:00h
           Place: Aula 507

    I will discuss a method to determine the chiral low-energy constants of QCD, as well as those of the weak Effective Hamiltonian, from lattice QCD simulations using finite-size scaling techniques. I will also review the present status of the lattice computations of these constants.


  • Title: "The top Yukawa Coupling at the ILC "


           Speaker:Cailin Farrell (UB-ECM)
           Date: Divendres 7-novembre-2008; 12:00h
           Place: Aula 507

    Since the values of the Yukawa Couplings are predictions of the Standard Model, any deviation from the predicted values would indicate new physics. A precise determination of the Yukawa Couplings is therefore necessary, both on the theoretical side and on the experimental side. The focus of this talk lies on the top Yukawa Coupling which is extracted from the process e^+e^- --> t t-bar H. The corresponding measurement is one of the important tasks of the future International Linear Collider (ILC). For the theoretical prediction, it is crucial to include threshold effects. After an introduction to velocity Non-Relativistic QCD (vNRQCD), which is an effective theory of the Standard Model accounting for these threshold effects, I present the results for the full next-to-leading logarithmic cross section. I will also comment on the prospects of measuring the top Yukawa coupling at the ILC.

  • Title: "Quarks, gluons and black holes"


           Speaker: David Mateos (ICREA & FFN)
           Date: Divendres 17-octubre-2008; 12:00h
           Place: Aula 507

    RHIC, the Relativistic Heavy Ion Collider in Brookhaven, New York, made a fascinating announcement in 2005: A new state of matter, dubbed the Quark-Gluon Plasma, had been created. Some of the properties of this soup of deconfined quarks and gluons are extremely surprising, both from the viewpoint of QCD and because they are seemingly related to the properties of black holes in string theory. I will describe this fascinating connection and explain how it can be used to make a universal prediction for the heavy ion collision experiments that will take place in the near future at the Large Hadron Collider at CERN, Geneva.


  • Title: "Non-zero baryon density on the lattice with the method of analytic continuation"


           Speaker: Alessandro Papa (Universita della Calabria & INFN, sezione di Cosenza)
           Date: Divendres 10-octubre-2008; 12:00h
           Place: Aula 507

    QCD at non-zero baryon density can be studied on the lattice by means of the method of analytic continuation from imaginary chemical potential. This method is carefully tested in a theory, 2-color QCD, which does not suffer from the sign problem and therefore permits the comparison of the analytic continuation with the result of direct Monte Carlo simulations. The case of SU(3) with finite isospin density is also considered.