Related papers: Charmonium Production at the LHC
In this work we study charmonium production in high multiplicity proton-proton collisions. We investigate the role of the spatial distribution of partons in the protons and assume that the proton has a Y shape. In this configuration quarks…
Gluon fragmentation to $\chicJ(1P)$ followed by single photon emission represents the dominant source of prompt $J/\Psi$'s at the Tevatron for $p_\perp \gtap 6 \GeV$. Since fragmenting gluons are approximately transverse, their products are…
It has been proposed that the large cross sections for prompt $\psi$, $\psi'$, and $\chi_c$ production at the Fermilab Tevatron $p\bar p$ collider can be explained by a dominant color-octet term in the fragmentation function for a gluon to…
The conventional description of heavy-flavour hadron production in pp collisions is based on a factorisation approach, assuming universal fragmentation functions among collision systems. Recent results on heavy-flavour baryon measurements…
Charmonia hadro- and photo-production are analyzed in the framework of the color-octet model taking into account higher-order effects induced by initial-state radiation of gluons. We argue that color-octet matrix elements obtained from…
We study the charmonium coherent photoproduction and hadroproduction consistently with modifications from both cold and hot nuclear matters. The strong electromagnetic fields from fast moving nucleus interact with the other target nucleus,…
We calculate the fragmentation function for charm quark into J/psi at the QCD next-to-leading-order (NLO) and find that the produced J/psi is of larger momentum fraction than it is at the leading-order. Based on the fragmentation function…
The production rate of prompt $\psi'$'s at large transverse momentum at the Tevatron is larger than theoretical expectations by about a factor of 30. As a solution to this puzzle, we suggest that the dominant $\psi'$ production mechanism is…
We report on forward-rapidity charmonium production in pp collisions at a center of mass energy $\sqrt{s} = 13$ TeV, as measured by ALICE at the LHC. Differential cross sections for both J/{\psi} and {\psi}(2S) are presented as a function…
The production of $\jpsi$ at large transverse momenta ($\pt > M_\jpsi$) in $p\bar p$ collisions is considered by including the mechanism of fragmentation. Both contributions of fragmentation to $\jpsi$ and of fragmentation to $\chi$ states…
We compute the contributions to large-$p_T$ $J/\psi$ production at HERA coming from fragmentation of gluons and charm quarks. We find that the charm quark fragmentation contribution dominates over the direct production of $J/\psi$ via…
Fragmentation is the dominant production mechanism for heavy hadronic bound states with large transverse momentum. We numerically calculate the initial $g\rightarrow H(Q\bar{Q})$ fragmentation functions (FFs) using the nonrelativistic QCD…
Charmonium production from the hadron gas formed in ultra-relativistic heavy-ion collisions is studied. Using the $J/\psi$-hadron absorption cross section determined from the nonperturbative quark-exchange model, which has a peak value…
We consider the charmonium production in thermalized hadronic medium created in ultrarelativistic heavy ion collisions at LHC energy. The calculations for the secondary $J/\psi$ and $\psi^,$ production by $D\bar D$ annihilation are…
Recent data from the Tevatron have revealed that the production rate of prompt charmonium is more than an order of magnitude larger than the best theoretical predictions of a few years ago. This surprising result can be understood by taking…
We present a calculation of the leading order QCD fragmentation functions for gluons to split into spin-triplet D-wave quarkonia. We apply them to evaluate the gluon fragmentation contributions to inclusive ^3D_J quarkonium production at…
We investigate the production of hadrons in nuclear collisions within the framework of the thermal (or statistical hadronization) model. We discuss both the ligh-quark hadrons as well as charmonium and provide predictions for the LHC…
Heavy charged lepton productions via gluon fusion at the LHC are revisited. Full loop calculations are adopted with an updated parton distribution function and electroweak data. Including contribution from new generation quarks in the loop,…
The hadroproduction of lepton pairs with mass $Q$ and finite transverse momentum $Q_T$ is dominated by quark-gluon scattering in the region $Q_T > Q/2$. This feature provides a new independent method for constraining the gluon density with…
We compute the cross section for exclusive double-diffractive gamma-gamma production at the Tevatron, $p{\bar p} \to p + \gamma\gamma + {\bar p}$, and the LHC. We evaluate both the gluon-gluon and quark-antiquark t-channel exchange…