31 research outputs found
Rare semileptonic decay of meson In QCD
The rare semileptonic decay
is analyzed, by using the three-point QCD sum rules. Taking into account the
two-gluon condensate contributions, the transition form factors related to this
decay are calculated and are used to determine the total decay width and
branching fraction. Our findings may be approved by future experiments.Comment: 15,
Coupling constants of bottom (charmed) mesons with pion from three point QCD sum rules
In this article, the three point QCD sum rules is used to compute the strong
coupling constants of vertices containing the strange bottomed ( charmed )
mesons with pion. The coupling constants are calculated, when both the bottom (
charm ) and pion states are off-shell. A comparison of the obtained results of
coupling constants with the existing predictions is also made. Key words:
strong coupling constant, meson, QCD sum rules, bottom, charm.Comment: 17pages, Latex. arXiv admin note: text overlap with arXiv:1104.2864,
arXiv:1103.0943, arXiv:hep-ph/0304193 by other author
Semileptonic and nonleptonic decays in three--point QCD sum rules and factorization approach
We analyze the semileptonic transition with , in the framework of the three--point QCD sum rules and the nonleptonic
decay within the QCD factorization approach. We study to
and transition form factors by separating the mixture
of the and states. Using the transition form factors of
the , we analyze the nonleptonic decay. We also
present the decay amplitude and decay width of these decays in terms of the
transition form factors. The branching ratios of these channel modes are also
calculated at different values of the mixing angle and compared
with the existing experimental data for the nonleptonic case.Comment: 28 Pages, 20 Figures and 9 Table
Semileptonic transition in three--point QCD sum rules and HQET with gluon condensate corrections
Taking into account the gluon condensate contributions, the form factors of
the semileptonic transition with are
calculated in the framework of the three point QCD sum rules. The heavy quark
effective theory limit of the form factors are also computed. The relevant
total decay width as well as the branching ratio are evaluated and compared
with the predictions of the other non-perturbative approaches.Comment: 27 Pages, 4 Figures and 4 Table
B_c meson rare decays in the light-cone quark model
We investigate the rare decays
and in the framework of the
light-cone quark model (LCQM). The transition form factors are calculated in
the space-like region and then analytically continued to the time-like region
via exponential parametrization. The branching ratios and longitudinal lepton
polarization asymmetries (LPAs) for the two decays are given and compared with
each other. The results are helpful to investigating the structure of
meson and to testing the unitarity of CKM quark mixing matrix. All these
results can be tested in the future experiments at the LHC.Comment: 9 pages, 11 figures, version accepted for publication in EPJ
Study of the rare B-s(0) and B-0 decays into the pi(+) pi(-) mu(+) mu(-) final state
A search for the rare decays and is performed in a data set corresponding to an integrated
luminosity of 3.0 fb collected by the LHCb detector in proton-proton
collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with
pion pairs that have invariant mass in the range 0.5-1.3 GeV/ and with
muon pairs that do not originate from a resonance are considered. The first
observation of the decay and the first
evidence of the decay are obtained and the
branching fractions, restricted to the dipion-mass range considered, are
measured to be and
, where the third
uncertainty is due to the branching fraction of the decay , used as a normalisation.Comment: 21 pages, 3 figures, 2 Table
Synthesis and decay process of superheavy nuclei with Z=119-122 via hot-fusion reactions
In this research article attempts have been made to calculate the superheavy-nuclei synthesis characteristics including, the potential energy parameters, fusion probability, fusion and evaporation residue (ER) cross sections as well as, decay properties of compound nucleus and the residue nuclei formation probability for elements with Z=119-122 by using the hot-fusion reactions. It is concluded that, although a selection of double magic projectiles such as 48Ca with high binding energy, simplifies the calculations significantly due to spherical symmetric shape of the projectile, resulting in high evaporation residue cross section, unfortunately, nuclei with do not exist in quantities sufficient for constructing targets for the hot-fusion reactions. Therefore, practically our selection is fusion reactions with titanium projectile because the mass production of target nuclei for experimental purposes is more feasible. Based upon our findings, it is necessary, for new superheavy-nuclei production with , to use neutron-rich projectiles and target nuclei. Finally, the maximal evaporation residue cross sections for the synthesis of superheavy elements with Z=119-122 have been calculated and compared with the previously founded ones in the literature