Exploring QCD dynamics in medium energy γA\gamma A semiexclusive collisions

We demonstrate that studies of the semiexclusive large angle photon - nucleus reactions: $\gamma + A\to h_1+h_2 +(A-1)^*$ with tagged photon beams of energies $6 \div 10$ GeV which can be performed in Hall D at Thomas Jefferson National Acceleration Facility (TJNAF) would allow to probe several aspects of the QCD dynamics: establish the $t$-range in which transition from soft to hard dynamics occurs, compare the strength of the interaction of various mesons and baryons with nucleons at the energies of few GeV, as well as look for the color transparency effects.Comment: 13 pages, 6 figures, minor revisions, version accepted in Phys. Lett.

Rescattering effects in antiproton-induced exclusive J/ψJ/\psi and ψ′\psi^\prime production on the deuteron

On the basis of the generalized eikonal approximation we study the exclusive reactions $\bar p d \to J/\psi\, n$ and $\bar p d \to \psi^\prime\, n$ in vicinity of the thresholds for charmonium production on a free proton target. It is shown that the rescattering of the incoming antiproton and outgoing charmonium on the spectator neutron leads to a depletion of the charmonium production at low- and to an enhancement at high transverse momenta. This is in qualitative agreement with previous studies of hard proton knockout in proton-deuteron collisions. We analyze different physical sources of uncertainty which may influence the extraction of the total charmonium-neutron cross section. The color transparency effect for the incoming $\bar p$ largely compensates the influence of charmonium rescattering both at low and high transverse momenta. Different choices of the deuteron wave function lead to significant uncertainties at high transverse momenta. As an outcome of the calculations of charmonium production, we also provide predictions on the production of open charm hadrons due to the dissociation of the charmonium on the neutron. It is shown that the open charm production cross section is proportional to the total charmonium-nucleon cross section and quite stable with respect to the variation of other parameters of the model. We thus suggest that open charm channels are most suited for future studies of charmonium-nucleon interactions at PANDA with a deuteron target.Comment: 28 pages, 8 figures, modified sec. 1 and 2, new Fig. 2, added references, results unchanged, version accepted in EPJ

Kaon production from 1 to 40 A GeV

Kaon production is studied within the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) model. Results are compared with experiment and with other models. The influence of the kaon potential on the kaon azimuthal distributions at SIS energies is considered. We also discuss the role of the many-body collisions at high-density phase of reaction.Comment: 6 pages, 4 figures, Proc. of the Int. Workshop on Hot and Dense Matter in Relativistic Heavy Ion Collisions, 09-12.04.2006, Budapes

Determination of the structure of the X(3872)X(3872) in pˉA\bar p A collisions

Currently, the structure of the $X(3872)$ meson is unknown. Different competing models of the $c\bar c$ exotic state $X(3872)$ exist, including the possibilities that this state is either a mesonic molecule with dominating $D^0 \bar D^{*0} +c.c.$ composition, a $c \bar c q \bar q$ tetraquark, or a $c \bar c$-gluon hybrid state. It is expected that the $X(3872)$ state is rather strongly coupled to the $\bar p p$ channel and, therefore, can be produced in $\bar p p$ and $\bar pA$ collisions at PANDA. We propose to test the hypothetical molecular structure of $X(3872)$ by studying the $D$ or $\bar D^{*}$ stripping reactions on a nuclear residue.Comment: 19 pages, 8 figures; version accepted in PL

Kaon production from 1 to 40 A GeV

Kaon production is studied within the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) model. Results are compared with experiment and with other models. The influence of the kaon potential on the kaon azimuthal distributions at SIS energies is considered. We also discuss the role of the many-body collisions at high-density phase of reaction.Comment: 6 pages, 4 figures, Proc. of the Int. Workshop on Hot and Dense Matter in Relativistic Heavy Ion Collisions, 09-12.04.2006, Budapes