High-Energy Photoproduction of Charmed States

Deconfinement: Concept, Theory, Test

“…The ideal way to cm .. c6 [ub] 2.00 in Fig. 6 it is seen that they agree well with the heavy quark theory result (19). with 2u = s --mz and 2u,, = M3, + 2M,],m;,.…”

“…with 2u = s --mz and 2u,, = M3, + 2M,],m;,. For this process, there are data [19], and (19) mt-c¤($) 2 12 nb (1 -vt/v)"» result is to calculate the cross section for the photoproduction of open charm, 0.,;,..,cE(s). The (18) is in fact quite well satisfied.…”

“…However, the "generalized spin" deconfinement threshold of 1 GeV/fm3 OCR Output cms energy per nucleon-nucleon collision), the initial energy density will be above the to reach thermal equilibrium. And for high enough incident energies (15)(16)(17)(18)(19)(20) produced in the collisions is expected to provide a rapid increase in entropy sufficient Abundant multiple scattering among the incident nucleons and the many secondaries to obtain them in small volumes and for short times in high energy nuclear collisions.…”

Exclusive Production of Neutral Vector Mesons at the Electron-Proton Collider HERA

“…Indeed, a suppression factor of about a factor of three was observed in elastic φ photoproduction at low energies [48] and for J/ψ photoproduction [64] this suppression was shown to be more than two orders of magnitude. On a model-independent basis it is reasonable to expect the symmetry to be restored for Q 2 ≫ M 2 V .…”

“…Soon after their discovery, the J/ψ and ψ(2S) mesons were observed in photoproduction at Cornell [61], FNAL [62], and SLAC [63], the FNAL measurements extending the photon energy range to 100 GeV. Photoproduction of charm states prior to 1985 is covered in the review by Holmes et al [64]. The production of J/ψ and ψ(2S) mesons was studied using fixed-target spectrometers in tagged and wideband photon beams for photon energies up to 225 GeV at FNAL [65].…”