Related papers: Testing J/psi Production and Decay Properties in H…
In the presence of an electric dipole coupling of the top quark to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- -> t tbar leads to the polarization of the top and anti-top. This polarization…
We investigate the effects of jet production on the following parameters: pseudorapidity, transverse momentum and transverse mass distributions of secondary charged particles produced in pp-collisions at 1.8 TeV, using the HIJING code.…
The shapes of invariant differential cross section for charged particle production as function of transverse momentum measured in heavy-ion collisions are analyzed. The data measured at RHIC and LHC are treated as function of energy density…
We compute leading-power fragmentation corrections to $J/\psi$ production at the Tevatron and the LHC. We find that, when these corrections are combined with perturbative corrections through next-to-leading order in the strong coupling…
The electroproduction of J/psi and psi(2S) mesons is studied in elastic, quasi-elastic and inclusive reactions for four momentum transfers 2 < Q^2 < 80 GeV^2 and photon-proton centre of mass energies 25 < W < 180 GeV. The data were taken…
Production of J/$\psi$ from nucleus-nucleus reactions depends sensitively on the dissociation cross section with light hadrons. Effective lagrangian methods are used to describe the hadronic degrees of freedom, including strangeness and…
We study the net dielectron production rates from an ensemble of thermal mesons, using an effective Lagrangian to model their interaction. The coupling between the electromagnetic and the hadronic sectors is done through the vector meson…
The short-distance Hamiltonian describing b->s(d)e^-e^+ in the standard model is used to obtain the decay spectrum of \bar{B}->K^-pi^+e^-e^+ and \bar{B}->pi^-pi^+e^-e^+, assuming the Kpi and pipi systems to be the decay products of K^* and…
We calculate the partonic cross sections for the hadroproduction of polarized chi_{cJ} mesons using the factorization formalism of nonrelativistic QCD. We also describe how the polarization is passed on to the J/psi mesons in the radiative…
An analysis of inelastic photoproduction of J/Psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80pb-1. Differential and double differential cross sections are measured…
Theoretical analyses of the results on quarkonium production at large transverse momentum ($p_T$) in $p\bar p$ collisions, at the Tevatron have revealed two novel features of the physics of quarkonium production : 1) the contribution of…
Linearly polarized gluons inside an unpolarized proton contribute to the transverse momentum distributions of (pseudo)scalar particles produced in hadronic collisions, such as Higgs bosons and quarkonia with even charge conjugation…
Based on the effective invariant amplitudes of the transitions $J/\psi\to\gamma X(J^P)$ and $X(J^P)\to\phi\phi$, the spin dependence of the $J/\psi\to\gamma X(J^P)\to\gamma\phi\phi$ decay amplitude is obtained in the case of the…
Recent DESY-HERA data on $J/\Psi$ elasticity distribution show that it emerges mostly as a fast particle. Interpreting photoproduction as a collision between a pre-formed charmed hadron and the proton, the outcoming $J/\Psi$ is a leading…
The reaction gamma p -> J/Psi p has been studied in ep interactions using the ZEUS detector at HERA. The cross section for elastic J/Psi photoproduction has been measured as a function of the photon-proton centre of mass energy W in the…
We consider a contribution to J/psi hadroproduction in which the meson production is mediated by three-gluon partonic state, with two gluons coming from the target and one gluon from the projectile. This mechanism involves double gluon…
Future planned lepton colliders, both in the circular and linear configurations, can effectively work as virtual and quasi-real photon-photon colliders and are expected to stimulate an intense physics program in the next few years. In this…
The production of J/psi and Upsilon mesons in pp collisions at sqrt(s) = 8 TeV is studied with the LHCb detector. The J/psi and Upsilon mesons are reconstructed in the mu+mu- decay mode and the signal yields are determined with a fit to the…
We calculate the transverse momentum p_T distribution for production of the Upsilon states in hadronic reactions. For small $p_T (\leq M_\Upsilon)$, we resum to all orders in the strong coupling alpha_s the process-independent large…
We study $J/\psi$ suppression in Pb+Pb collisions at CERN-SPS energies in hadronic matter with energy- and temperature-dependent charmonium dissociation cross sections calculated in the quark-interchange model of Barnes and Swanson. We find…