242 research outputs found
Excited mesons in decays
In the presented paper exclusive decays and
are analyzed. It is shown that contributions of the
excited mesons should be taken into account to describe these decays. It
is also shown that, unlike the corresponding lepton decays, peaks in
distributions caused by these resonances are clearly seen and can
be easily separated. Theoretical predictions for the branching fractions of the
reactions and distributions are also presented.Comment: 6 pages, 5 figure
Production at LHC
Inclusive production of pair in proton-proton interation at
LHCb is considered. This process is forbidden at leading order of perturbation
theory, so such channels as double parton scattering, pair
production with subsequent radiative decays of -wave quarkonia,
contributions of color-octet states, and NLO corrections are studied in
details. For all these channels we present theoretical predictions of total
cross sections at LHCb and distributions over different kinematical variables.
According to presented in the paper results, double parton interaction gives
main contribution to the cross section of the considered reaction.Comment: 8 pages, 4 figures, 1 table. To be published in the proceedings of
CHARM-2015, Detroit, MI, 18-22 May 201
Production of K mesons in exclusive decays
The paper is devoted to investigation of mesons production in exclusive
decays and . In the framework of resonance approximation we
obtain theoretical predictions for branching fractions of these decays and
present distributions over different kinematical variables.Comment: minor changes, typos correcte
Leading order NRQCD and Light-Cone Analysis of Exclusive Charmonia Production in Radiative -boson Decays
The presented paper is devoted to theoretical analysis of charmonium mesons
, , , and production in exclusive
radiative boson decays in the frameworks of Nonrelativistic Chromodynamic
and amplitude expansion on the light-cone. In the framework of light-cone
expansion amplitudes and widths of all processes are described with one
universal relation. It is interesting to note that from this relation it
follows automatically which component of boson (either vector or axial)
gives contribution to the width of the particular decay. It is shown that the
effect of internal quark motion almost doubles theoretical predictions for
production of -wave charmonia and meson.Comment: Minor changes, some references adde
Charmonia Production in Decays
In the presented paper production of charmonium state in
exclusive decays is analyzed in the framework of
both leading order Nonrelativistic Quantum Chromodynamics (NRQCD) and
light-cone expansion (LC) models. Analytical and numerical predictions for the
branching fractions of these decays in both approaches are given. The typical
value of the branching fractions is and it turns out the LC
results are about 4 times lager than NRQCD ones, so the effect of internal
quark should be taken into account. Some estimates of color-octet contributions
are presented and it is shown, that these contributions could be comparable
with color-singlet results.Comment: 9 pages, 4 figures, 2 table
Initial state radiation corrections to double charmonium production in one-photon electron-positron annihilation
In this paper initial state radiation corrections to double production of
charmonium mesons on one-photon electron-positron annihilation at center of
mass energy \sqrt{s}=10.6\GeV are studied. It is shown, that these
corrections have noticeable effect and must be taken into consideration.Comment: 5 pages, 5 figures, minor change
On double charmonium production through two-photon \e^+ e^- annihilation at
Recent measurements of the Belle Collaboration of the exclusive production of
two charmonia in the annihilation differ substantially from
theoretical predictions. Recently it was suggested that a significant part of
this discrepancy can be explained by the process and value
for its cross-section was published. In this paper it is shown, that these
results are incorrect and the values for the cross-sections of the production
of different vector charmonia are presented.Comment: 4 pages, 2 figures; minor change
Charmonium production in hadronic experiments at the energy 70 GeV
The production of the charmonium states in hadronic experiments is considered
in NLO at the strong coupling constant. It is shown, that such an approach
solves some significant problems, arising when only leading order processes are
considered. In particular, in such a consideration distributions over the
transverse momentum of the final charmonium can be obtained. There appears also
a natural explanation to the existence of -meson in final state,
that is observed experimentally and cannot be produced in leading order
processes.Comment: 28 pages, 13 figure
Weak decays of doubly heavy baryons: decays to system of mesons
In the presented article we consider exclusive weak decays of doubly heavy
baryons with spin with production of leptonic pair or a set of light
mesons. Using QCD factorization theorem and spectral functions approach we
obtain theoretical predictions for the partial probabilities of these decays
and distributions over various kinematic variables. According to the obtaining
results partial probabilities of some of researched decays are large enough to
be observed experimentally.Comment: Small changes (spectral functions' parametrization updated, some of
the branching fractions have slightly change, affiliation information is
updated). Accepted for publication in Phys.Rev.
Double Charmonia Production in Exclusive Boson Decays
This article is devoted to systematic analysis of double charmonium
production in exclusive boson decays in the framework of Nonrelativistic
Quantum Chromodynamic (NRQCD) and leading twist light-cone (LC) models.
Theoretical predictions for branching fractions of all considered decays are
presented. According to obtained results in the case of allowed by helicity
suppression rule processes the effect of internal quark motion increases the
branching fraction by a factor 1.5, while for forbidden reactions LC
predictions are strictly zero, while NRQCD ones are significantly smaller than
for allowed.Comment: 10 pages, 2 figures, 2 tables. arXiv admin note: substantial text
overlap with arXiv:1706.0409
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