10 research outputs found
Study of f_0(980) and f_0(1500) from B_s \to f_0(980)K, f_0(1500)K Decays
In this paper, we calculate the branching ratios and CP-violating asymmetries
for \bar B^0_s \to f_0(980)K, f_0(1500)K within Perturbative QCD approach based
on k_T factorization. If the mixing angle falls into the range of
25^\circ<\theta<40^\circ, the branching ratio of \bar B^0_s\to f_0(980)K is
2.0\times 10^{-6}<{\cal B}(\bar B^0_s\to f_0(980)K)<2.6\times 10^{-6}, while
lies in the range of 140^\circ<\theta<165^\circ, {\cal B}(\bar
B^0_s\to f_0(980)K) is about 6.5\times 10^{-7}. As to the decay {\cal B}(\bar
B^0_s\to f_0(1500)K), when the mixing scheme \mid f_0(1500)>=0.84\mid s\bar
s>-0.54\mid n\bar n> for f_0(1500) is used, it is difficult to determine which
scenario is more preferable than the other one from the branching ratios for
these two scenarios, because they are both close to 1.0\times10^{-6}. But there
exists large difference in the form factor F^{\bar B_s^0\to f_0(1500)} for two
scenarios.Comment: 14 pages, 3 figures, submitted to J. Phys.
Charmless hadronic decays in the perturbative QCD approach
In this work, we calculate the branching ratios (BRs) and the polarization
fractions of sixty two charmless two-body meson decays into final states
involving one vector and one axial-vector meson () or two axial-vector
mesons() within the framework of perturbative QCD (pQCD) approach
systematically, where is either a or axial-vector meson.
All considered decay channels can only occur through the annihilation
topologies in the standard model. Based on the perturbative calculations and
phenomenological analysis, we find the following results: (i) the CP-averaged
BRs of the considered sixty two decays are in the range of to
; (ii) since the behavior for meson is much different from
that of meson, the BRs of decays are
generally larger than that of decays in the
pQCD approach; (iii) many considered decays modes, such as , , etc, have sizable BRs within the reach of the LHCb
experiments; (iv) the longitudinal polarization fractions of most considered
decays are large and play the dominant role; (v) the pQCD predictions for
several decays involving mixtures of and/or mesons are highly
sensitive to the values of the mixing angles, which will be tested by the
ongoing LHC and forthcoming Super-B experiments; (vi) the CP-violating
asymmetries of these considered decays are absent in the standard model
because only one type tree operator is involved.Comment: 31 pages, 1 figur
eta_c production at the Large Hadron Collider
We have studied the production of the 1S_0 charmonium state, eta_c, at the
Large Hadron Collider (LHC) in the framework of Non-Relativistic Quantum
Chromodynamics (NRQCD) using heavy-quark symmetry. We find that NRQCD predicts
a large production cross-section for this resonance at the LHC even after
taking account the small branching ratio of eta_c into two photons. We show
that it will be possible to test NRQCD through its predictions for eta_c, with
the statistics that will be achieved at the early stage of the LHC, running at
a center of mass energy of 7 TeV with an integrated luminosity of 100 pb^{-1}Comment: 8 pages, 2 figure
Theoretical issues in J/psi suppression
Two decades ago Matsui and Satz suggested that Debye screening in the
quark-gluon plasma would result in J/psi suppression in heavy ion collisions.
Much has happened in the subsequent years, and the picture of quark-gluon
plasma at present is rapidly evolving - what does it imply for the J/psi
suppression? What are the recent RHIC and SPS results trying to tell us? What
else has to be done? This talk is an attempt to address these questions.Comment: 8 pages, 6 figures, invited plenary talk at Quark Matter -2006,
Shanghai, China, November 14-20, 200
pQCD Calculations of Heavy Quark and J/psi Production
We review the present status of theoretical predictions for both closed
(J/psi) and open heavy quark production in high energy collisions, and their
comparisons to experimental data.Comment: 8 pages, invited talk given at Quark Matter 2006, Shanghai, China,
14-20 November 200
and coupling constants in QCD sum rules
The coupling constants and
are calculated in the framework of
three-point QCD sum rules. The correlation functions responsible for these
coupling constants are evaluated considering contributions of both and
mesons as off-shell states, but in the absence of radiative
corrections. The results, and are
obtained for the considered strong coupling constants.Comment: 13 Pages and 11 Figure