Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userAssociated Charmonium Production in Low Energy p-pbar Annihilation
123
0
0.0
(
0
)
Authors
T.Barnes Physics Division
Ask ChatGPT about the research
No Arabic abstract
The QCD mechanisms underlying the exclusive strong decays and hadronic production amplitudes of charmonium remain poorly understood, despite decades of study and an increasingly detaled body of experimental information. One set of hadronic channels of special interest are those that include baryon-antibaryon states. These are being investigated experimentally at BES and CLEO-c in terms of their baryon resonance content, and are also of interest for the future PANDA experiment, in which charmonium and charmonium hybrids will be produced in p-pbar annihilation in association with light mesons. In this paper we develop a simple initial-state light meson emission model of the near-threshold associated charmonium production processes p pbar -> pi0 ccbar, and evaluate the differential and total cross sections for these reactions in this model. (Here we consider the ccbar states eta_c, J/psi, psi, chi_0 and chi_1.) The predicted near-threshold cross section for p pbar -> pi0 J/psi is found to be numerically similar to two previous theoretical estimates, and is roughly comparable to the (sparse) existing data for this process. The theoretical charmonium angular distributions predicted by this model are far from isotropic, which may be of interest for PANDA detector design studies.
rate research
Read More
In this paper we summarize our recent results for low energy associated charmonium production cross sections, using 1) crossing symmetry, and 2) an explicit hadronic model. These predictions are of relevance to the planned charmonium and charmonium hybrid production experiment PANDA at GSI.
The cross sections for the charmonium production processes p pbar -> m Psi, where m is a light meson and Psi is a charmonium state, are of great interest for the planned p-pbar experiment PANDA. In this paper we estimate these cross sections using known results for the decays Psi -> m p pbar which are related to these reactions by crossing. In lieu of detailed experimental data on the decay Dalitz plots, we assume a constant amplitude as a first approximation; this implies a simple relation between the cross sections and decay widths. The single measured exclusive cross section of this type is p pbar -> pi0 J/psi, which was reported by E760 to be 130 +/- 25 pb near sqrt(s) = 3.5-3.6 GeV. In comparison, our constant amplitude estimate is about 300 pb at this energy. This suggests that our approach is useful as a simple estimate, but should be refined through detailed modeling of resonances and other energy-dependent effects in the experimental Psi -> m p pbar Dalitz plots.
The production cross sections of $J/psi~eta_b$, $Upsilon;eta_c$ pairs in a single boson $e^+e^-$ annihilation have been studied in a wide range of energies, which will be achieved at future $e^+e^-$ colliders. The main color singlet contributions to the production processes are taken into account, including the one loop QCD contribution.
We propose to investigate various charmonium states using their common decay channel to p pbar at LHC. Having the branching ratios for charmonium decaying into the p pbar final state measured or calculated, we propose to measure the charmonium production rate for both hadroproduction including soft-diffraction and inclusive production from b-hadron decays. We discuss the theoretical impacts in QCD of measuring different charmonium production rates and also the experimental prospects at LHCb, in particular, those for yet unmeasured eta_c and h_c.
The energy dependence of the cross sections of $pbar p$, $nbar n$, and meson production in $e^+e^-$ annihilation in the vicinity of the $pbar p$ and $nbar n$ thresholds is studied. The proton-neutron mass difference and the $pbar p$ Coulomb interaction are taken into account. The values of the cross sections are very sensitive to the parameters of the optical potential. It is shown that the commonly accepted factorization approach for the account of the Coulomb interaction does not work well enough in the vicinity of the threshold due to the finite size of the optical potential well.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
