Cheuk-Yin Wong

Heavy quarkonia in quark-gluon plasma

Q in quenched QCD, we study the binding energies and wave functions of heavy quarkonia in a quark-gluon plasma. By minimizing the grand potential in a simplified schematic model, we find that the proper color-singlet Q- ¯ Q potential can be obtained from the total internal energy U1 by subtracting the gluon internal energy contributions. We carry out this subtraction in the local energy-density approximation in which the gluon energy density can be related to the local gluon pressure by the quark-gluon plasma equation of state. We find in this approximation that the proper color-singlet Q- ¯ Q potential is approximately F1 for T ∼ Tc and it changes to 3 F1 + 1 U1 at high temperatures. In this potential model, the J/ ψ is weakly bound above the phase-transition temperature Tc, and it dissociates spontaneously above 1.62Tc, whereas χc and ψ � are unbound in the quark-gluon plasma. The bottomium states ϒ, χb ,a ndϒ � are bound in the quark-gluon plasma and they dissociate at 4.1Tc, 1.18Tc, and 1.38Tc respectively. For comparison, we evaluate the heavy quarkonium binding energies also in other models using the free energy F1 or the total internal energy U1 as the Q- ¯ Q potential. The comparison shows that the model with the new Q- ¯ Q potential proposed here gives dissociation temperatures that agree best with those from spectral function analyses. We evaluate the cross section for σ (g + J/ ψ → c + ¯ c) and its inverse process to determine the J/ ψdissociation width and the rate of J/ ψ production by recombining c and ¯ c in the quark-gluon plasma.

Tsallis fits to p T spectra and multiple hard scattering in p p collisions at the LHC

Phenomenological Tsallis fits to the CMS, ATLAS, and ALICE transverse momentum spectra of hadrons for

Molecular states of heavy quark mesons

pp

Landau Hydrodynamics Reexamined

collisions at LHC were recently found to extend over a large range of the transverse momentum. We investigate whether the few degrees of freedom in the Tsallis parametrization may arise from the relativistic parton-parton hard-scattering and related processes. The effects of the multiple hard-scattering and parton showering processes on the power law are discussed. We find empirically that whereas the transverse spectra of both hadrons and jets exhibit power-law behavior of

Toroidal and spherical bubble nuclei

1/{p}_{T}^{n}

Dynamics of nuclear fluid: (I). Foundation

at high

Tsallis Fits to p_t Spectra for pp Collisions at LHC

{p}_{T}

From QCD-based hard-scattering to nonextensive statistical mechanical descriptions of transverse momentum spectra in high-energy pp and pp¯ collisions

, the power indices

Fusion threshold energy in heavy-ion reactions

n

Elastic and inelastic proton scattering from 112, 114Cd

for hadrons are systematically greater than those for jets, for which