Related papers: Gluon Fragmentation into $^3P_J$ Quarkonium
Next-to-leading order corrections to fragmentation functions in a light-cone gauge are discussed. This gauge simplifies the calculation by eliminating many Feynman diagrams at the expense of introducing spurious poles in loop integrals. As…
Recent experiments have found spin alignment of $J/\psi$ with respect to event plane in heavy ion collisions, suggesting a medium effect that is spin dependent. We propose a possible mechanism with polarized dissociation from the motion of…
For radially excited heavy quarkonia $ V=\psi(2S) $ and $ \Upsilon(2S) $, the nodal structure of their wave function renders the three-gluon decay $ V\to ggg $ acutely sensitive to relativistic corrections, presenting a longstanding…
We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting…
We study the transverse-momentum spectrum of quarkonium production from single light-parton fragmentation mechanism. In the case of semi-inclusive deep inelastic scattering, we observe that there are two possible initiating processes,…
We calculate the transverse momentum dependent gluon-to-gluon splitting function within $k_T$-factorization, generalizing the framework employed in the calculation of the quark splitting functions in [1-3] and demonstrate at the same time…
The geometric clustering of partons in the transverse plane of nuclear collisions leads for increasing A or sqrt(s) to percolation. In the resulting condensate, the partons are deconfined but not yet in thermal equilibrium. We discuss…
Fragmentation functions are determined for pions, kaons, and nucleons by a global analysis of charged-hadron production data in electron-positron annihilation. The optimum functions are obtained in both leading order (LO) and…
We calculate the heavy quarkonium energy levels and decay widths in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> T >> m alpha_s^2 >> m_D (m being the heavy-quark mass), at order m…
The leading order non-relativistic QCD result for the quarkonium-hadron interaction cross section is derived by using the QCD factorization formula combined with the Bethe-Salpeter amplitude for the heavy quark bound state. Our result shows…
Recent lattice calculations showed that the quarkonia will survive beyond the phase transition temperature, and will dissolve at different temperatures depending on the type of the quarkonium. In this work, we calculate the thermal width of…
The interaction of quarkonium with nuclei is studied in the $m_Q\rightarrow \infty$ limit of QCD, where the binding energy is found to be exactly computable. The dominant contribution to the interaction is from two-gluon operators. The…
Recent results on the total production and angular distribution of charged particles originated from the fragmentation of quark and gluon jets are presented. Experimental studies of the multiplicity as a function of the quark and gluon jet…
Fragmentation functions and their uncertainties are determined for pion, kaon, and proton by a global $\chi^2$ analysis of charged-hadron production data in electron-positron annihilation and by the Hessian method for error estimation. It…
We present new sets of fragmentation functions for charged pions, charged kaons, and protons, both at the leading and next-to-leading orders. They are fitted to the scaled-momentum distributions of these hadrons measured in e+e-…
The phase between three-gluon and one-photon amplitudes in psi(2S) and psi(3770) decays is analyzed.
We develop a formalism for resumming threshold double logarithms that appear in fragmentation functions for production of heavy quarkonia. Threshold singularities appear in fixed-order calculations of quarkonium fragmentation functions in…
We discuss diffractive dissociation of gluons into heavy quark pairs. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks. The amplitude for the $g p \to Q \bar Q p$ is derived in the impact…
We review the physics of quarkonium production at high energy colliders, with a specific emphasis on production $via$ fragmentation. We discuss the fragmentation picture for the production of quarkonia at large-$p_T$ at the Tevatron and…
We present new sets of proton fragmentation functions describing the production of protons from the gluon and each of the quarks, obtained by a global fit to all relevant data sets extracted from the single-inclusive electron-positron…