http://www.recercat.cat:80/handle/2072/169514 www.ub.edu Sat, 25 May 2013 16:22:16 GMT 2013-05-25T16:22:16Z http://www.recercat.cat:80/bitstream/id/26415/ http://www.recercat.cat:80/handle/2072/169514 http://www.recercat.cat:80/handle/2072/179986 Cherenkov mesons as in-medium quark energy loss Casalderrey-Solana, Jorge; Fernández Moreno, Daniel; Mateos, David (Mateos Solé) We recently showed that a heavy quark moving su ciently fast through a quark-gluon plasma may lose energy by Cherenkov-radiating mesons [1]. Here we review our previous holographic calculation of the energy loss in N = 4 Super Yang-Mills and extend it to longitudinal vector mesons and scalar mesons. We also discuss phenomenological implications for heavy-ion collision experiments. Although the Cherenkov energy loss is an O(1=Nc) effect, a ballpark estimate yields a value of dE/dx for Nc = 3 which is comparable to that of other mechanisms. http://www.recercat.cat:80/handle/2072/179986 http://www.recercat.cat:80/handle/2072/179983 Single-inclusive production of large-pT charged particles in hadronic collisions at TeV energies and perturbative QCD predictions Arleo, François; Enterria i Adan, David G. d'; Yoon, Andre S. http://www.recercat.cat:80/handle/2072/179983 http://www.recercat.cat:80/handle/2072/179985 Holographic superconductors from gauged supergravity Aprile, Francesco; Roest, Diederik; Russo, J. G. http://www.recercat.cat:80/handle/2072/179985 http://www.recercat.cat:80/handle/2072/179984 An AdS/QCD model from tachyon condensation: II Iatrakis, Ioannis; Kiritsis, Elias; Paredes, Ángel A simple holographic model is presented and analyzed that describes chiral symmetry breaking and the physics of the meson sector in QCD. This is a bottom-up model that incorporates string theory ingredients like tachyon condensation which is expected to be the main manifestation of chiral symmetry breaking in the holographic context. As a model for glue the Kuperstein-Sonnenschein background is used. The structure of the flavor vacuum is analyzed in the quenched approximation. Chiral symmetry breaking is shown at zero temperature. Above the deconfinement transition chiral symmetry is restored. A complete holographic renormalization is performed and the chiral condensate is calculated for different quark masses both at zero and non-zero temperatures. The 0++, 0¿+, 1++, 1¿¿ meson trajectories are analyzed and their masses and decay constants are computed. The asymptotic trajectories are linear. The model has one phenomenological parameter beyond those of QCD that affects the 1++, 0¿+ sectors. Fitting this parameter we obtain very good agreement with data. The model improves in several ways the popular hard-wall and soft wall bottom-up models. http://www.recercat.cat:80/handle/2072/179984 http://www.recercat.cat:80/handle/2072/179458 Weakly linked binary mixtures of F = 1 87Rb Bose-Einstein condensates Melé Messeguer, Marina; Juliá-Diaz, Bruno; Guilleumas, Montserrat; Polls Martí, Artur; Sanpera Trigueros, Anna We present a study of binary mixtures of Bose-Einstein condensates confined in a double-well potential within the framework of the mean field Gross-Pitaevskii (GP) equation. We re-examine both the single component and the binary mixture cases for such a potential, and we investigate what are the situations in which a simpler two-mode approach leads to an accurate description of their dynamics. We also estimate the validity of the most usual dimensionality reductions used to solve the GP equations. To this end, we compare both the semi-analytical two-mode approaches and the numerical simulations of the one-dimensional (1D) reductions with the full 3D numerical solutions of the GP equation. Our analysis provides a guide to clarify the validity of several simplified models that describe mean-field nonlinear dynamics, using an experimentally feasible binary mixture of an F = 1 spinor condensate with two of its Zeeman manifolds populated, m = ±1. http://www.recercat.cat:80/handle/2072/179458 http://www.recercat.cat:80/handle/2072/169572 Open-charm mesons in nuclear matter at finite temperature beyond the zero-range approximation Jiménez-Tejero, C. E.; Ramos Gómez, Àngels; Tolós Rigueiro, Laura; Vidaña Haro, Isaac http://www.recercat.cat:80/handle/2072/169572 http://www.recercat.cat:80/handle/2072/169571 Constraints on effective field theory parameters for the Lambda N -> NN transition Perez Obiol, Axel; Parreño García, Assumpta; Juliá-Diaz, Bruno The relation between the low-energy constants appearing in the effective field theory description of the Lambda N -& NN transition potential and the parameters of the one-meson-exchange model previously developed is obtained. We extract the relative importance of the different exchange mechanisms included in the meson picture by means of a comparison to the corresponding operational structures appearing in the effective approach. The ability of this procedure to obtain the weak baryon-baryon-meson couplings for a possible scalar exchange is also discussed. http://www.recercat.cat:80/handle/2072/169571