4,773 research outputs found
Evading 1/m_b-suppressed IR divergencies in QCDF: Bs-->KK Decays and B_{d,s} mixing
We analyze the deviations of the mixing induced CP asymmetry in B-->phi Ks
from sin(2beta), as well as the deviations of the asymmetries in Bs-->K*K*,
Bs-->phi K* and Bs-->phi phi from sin(2beta_s), that arise in SM due to penguin
pollution. We use a theoretical input which is short-distance dominated in
QCD-factorization and thus free of IR-divergencies. We also provide alternative
ways to extract angles of the unitarity triangle from penguin-mediated decays,
and give predictions for Bs-->K*K* observables.Comment: 5 pages. Talk given at the International Workshop on Quantum
Chromodynamics: QCD@Work 2007, Martina Franca, Italy, June 200
Instabilities in two flavor quark matter
I discuss briefly the instabilities of two flavor quark matter, paying
attention to the gradient instability which develops in the g2SC phase in the
Goldstone sector.Comment: 6 pages. Talk given at QCD@Work07, Martina Franca (Italy). Some typos
corrected, one reference adde
Possible crossover from BCS superconductivity to Bose-Einstein condensate in quark matter
The possibility of the crossover from the BCS pairing to the Bose-Einstein
condensate (BEC) of diquarks with going down in density is discussed in the
framework of in the Nambu Jona-Lasinio (NJL) model. We find that the quark
matter at moderate density may be close to the intermediate of the crossover,
the precursory regime to the BEC phase.Comment: 6 pages, 4 figures, Contributed to International Workshop on Quantum
Chromodynamics: QCD@Work 2007, Martina Franca, Valle d'Itria, Italy, 16-20
Jun 200
Chiral Lagrangians with tensor sources
The implementation of tensor sources in Chiral Lagrangians allows the
computation of Green functions and form factors involving tensor currents, that
is, quark bilinears of the form \bar{q}_i\sigma^{\mu\nu}q_j. Whereas only four
new terms show up at O(p^4), we find around a hundred of them at O(p^6). So it
becomes essential to ensure that this set o operators is indeed minimal and
non-redundant (i.e., it is a basis). We discuss two phenomenological
applications in the context of vector meson resonances and the radiative pion
decay.Comment: Talk given at the 4th International Worshop on Quantum
ChromoDynamics, Theory and experiment, June 16-20, 2007. Martina Franca -
Valle d'Itria - Ital
Instabilities in two flavor quark matter
I discuss briefly the instabilities of two flavor quark matter, paying
attention to the gradient instability which develops in the g2SC phase in the
Goldstone sector.Comment: 6 pages. Talk given at QCD@Work07, Martina Franca (Italy). Some typos
corrected, one reference adde
Holographic description of glueballs in a deformed AdS-dilaton background
We investigate the mass spectra of scalar and vector glueballs in the
so-called bottom-up approach of the AdS/QCD correspondence. The holographic
model of QCD includes a static dilaton background field. We study the
constraints on the masses coming from perturbing the dilaton field and the
geometry of the bulk.Comment: Talk given at the International Workshop on Quantum Chromodynamics:
QCD@Work 2007, Martina Franca, Italy, 16-20 June 200
Probing Universal Extra Dimensions through rare decays induced by transition
A few and decays induced by transition are
studied in the Standard Model and in the framework of the Appelquist, Cheng and
Dobrescu (ACD) model, which is a New Physics scenario where a single universal
extra dimension is considered. In particular, we investigate the sensitivity of
the observables to the radius of the compactified extra dimension.Comment: LaTex, 7 pages, 4 eps figures. Contribution to the International
Workshop QCD@Work 2007, June 16-20, Martina Franca - Ital
Determining chiral couplings at NLO
We present a general method that allows to estimate the low-energy constants
of Chiral Perturbation Theory up to next-to-leading corrections in the 1/N(C)
expansion, that is, keeping full control of the renormalization scale
dependence. As a first step we have determined L(8) and C(38), the couplings
related to the difference of the two-point correlation functions of two scalar
and pseudoscalar currents, L(8)(mu_0) = (0.6 \pm 0.4) 10^{-3} and C(38)(mu_0) =
(2 \pm 6) 10^{-6}$, with mu_0 = 0.77 GeV. As in many effective approaches, one
of the main ingredients of this method is the matching procedure: some comments
related to this topic are presented here.Comment: Talk given at the International Workshop on Quantum Chromodynamics
QCD@work 2007, 16th-20th June (2007), Martina Franca (Italy). 6 p
Chromomagnetic Instability and Gluonic Phase at Nonzero Temperature
We describe the results of recent studies of a chromomagnetic instability and
a gluonic phase in neutral two-flavor quark matter at nonzero temperature.Comment: 6 pages, 3 figures, prepared for International Workshop on Quantum
Chromodynamics: QCD@Work 2007, Martina Franca, Valle d'Itria, Italy, 16-20
Jun 200
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