Related papers: Digluon contribution to $J/\psi$ production
The analyses of large transverse momentum charmonium production at the Tevatron have shown that fragmentation of gluons is an important production mechanism. We study large-$p_T$ charmonium production in $pp$ collisions at the LHC, and find…
We discuss inclusive production of pairs of $J/\psi$ quarkonia. Both leading-order single parton (box) contribution and double-parton contributions are included. In addition we discuss a contribution of higher-order two-gluon exchange and a…
We consider a contribution to J/psi hadroproduction in which the meson production is mediated by three-gluon partonic state, with two gluons coming from the target and one gluon from the projectile. This mechanism involves double gluon…
We compute the contributions due to gluon and heavy-quark fragmentation to quarkonium production at large transverse momentum in $\bar p p$ and $p p$ collisions. For inclusive $J/\psi$ production, there is a large contribution from the $g…
We consider the production of $J/\psi$ and $\psi(2S)$ mesons originating from the decays of $b$-flavored hadrons at the LHC using the $k_T$-factorization approach. Our analysis covers both inclusive charmonia production and production of…
The three-gluon contribution to $J/\psi$ hadroproduction is calculated within perturbative QCD in the $k_T$ factorization framework. This mechanism involves double gluon density and enters at a non-leading twist, but it is enhanced at large…
A contribution to $J/\psi$ hadroproduction is analyzed in which the meson production is mediated by three-gluon partonic state, with two gluons coming from the target and one gluon from the projectile. This mechanism involves double gluon…
We consider the process of double $J/\psi$ production in $pp$ collisions at the LHC in the framework of $k_T$-factorization approach. We focus on the gluon fragmentation mechanism which is related to multiple gluon emission in the initial…
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…
We study the contribution of gluon induced partonic subprocesses to Z gamma pair production at hadron colliders. These processes contribute only at next-to-next-to-leading order but are potentially enhanced by two factors of the gluon…
We consider the associated production of $J/\psi$ mesons and muons originating from the $b$-flavored hadron decays and non-prompt double $J/\psi$ production at the LHC using the $k_T$-factorization approach. To describe the inclusive…
The standard model production of two photons is one of the most important backgrounds to light Higgs boson production at the LHC. In this talk we discuss the di-photon background, with emphasis on the effects of the recently calculated…
We investigate how charmonium hadroproduction at fixed-target energies can be used to constrain the gluon distribution in pions. Using nonrelativistic QCD (NRQCD) formulation, the $J/\psi$ and $\psi(2S)$ cross sections as a function of…
In the present work we study production of $J/\psi + \chi_c$ and $J/\psi + J/\psi$ in LHC. The first process is forbidden at the leading order in gluon fusion due to the $C$-parity conservation, and the first non-vanishing contribution is…
In a previous paper [Phys. Rev. D 68, 034017 (2003)], we investigated the inclusive production of prompt J/psi mesons in polarized hadron-hadron, photon-hadron, and photon-photon collisions in the factorization formalism of nonrelativistic…
The dominance of chi_0 in the data for e+e- to psi + chi_J(c\bar{c}) is shown to violate OZI factorization. Single gluon exchange gives a non-factorizing effective S.L interaction that generates a large scalar production amplitude. This…
We present the preliminary results of a calculation of the fragmentation contribution to charmonium production at large transverse momentum in $p\bar{p}$ colliders. The fragmentation of gluons and charm quarks is the dominant direct…
Using the two-component model that includes charmonium production from initial nucleon-nucleon hard scattering and regeneration in the produced quark-gluon plasma, we study $J/\psi$ production in heavy ion collisions at SPS, RHIC and LHC.…
We study open b\bar{b} production at large rapidity at the LHC in an attempt to pin down the gluon distribution at very low x. For the LHC energy of 7 TeV, at next-to-leading order (NLO), there is a large factorization scale uncertainty. We…
We study high mass dilepton production from gluon-induced processes, $g q \to q \gamma^*$, $g \bar q \to \bar q \gamma^*$, and $g g \to q \bar q \gamma^*$, in a thermally equilibrated but chemically under-saturated partonic matter that is…