Related papers: Resolving negative cross section of quarkonium had…
We study soft-gluon corrections for the associated production of a single top quark and a $Z$ boson ($tqZ$ production) at hadron colliders. We find that the radiative corrections are dominated by soft-gluon emission. We calculate the…
We calculate the ${\cal O}(\alpha_s^3)$ short-distance, QCD collinear-factorized coefficient functions for all partonic channels that include the production of a heavy quark pair at short distances. This provides the first power correction…
We use fragmenting jet functions (FJFs) in the context of quarkonia to study the production channels predicted by NRQCD (3S_1^(1), 3S_1^(8), 1S_0^(8), 3P_J^(8)). We choose a set of FJFs that give the probability to find a quarkonium with a…
We have determined the theoretical predictions for the cross-sections of squark and gluino production at $\ppb$ and $pp$ colliders (Tevatron and LHC) in next-to-leading order of supersymmetric QCD. By reducing the dependence on the…
We argue that the collinear factorization of the fragmentation functions in high energy hadron and nuclei collisions breaks down at transverse momenta kT < Qs/g due to high parton densities in the colliding hadrons and/or nuclei. We…
We show that when the factorized cross section for heavy quarkonium production includes next-to-leading power (NLP) contributions associated with the production of the heavy quark pair at short distances, it naturally reproduces all high…
We introduce the transverse momentum dependent fragmenting jet function (TMDFJF), which appears in factorization theorems for cross sections for jets with an identified hadron. These are functions of $z$, the hadron's longitudinal momentum…
The cross section for top quark pair production factorizes at small transverse momentum of the heavy quark pair, $q_T$. One of the key ingredients that appears in the factorization formula is the soft function, which mediates soft gluon…
The quarkonium hadroproduction in association with a photon at high energies provides a probe of the dynamics of the strong interactions as it is dependent on the nuclear gluon distribution. Therefore, it could be used to constrain the…
The near-threshold photo- and electroproduction of heavy vector quarkonia off the proton provides direct access to its gluonic structure. In particular, the cross section for $J/\Psi$ photoproduction near threshold is governed by the…
We compute fragmentation corrections to hadroproduction of the quarkonium states $J/\psi$, $\chi_{cJ}$, and $\psi(2S)$ at leading power in $m_c^2/p_T^2$, where $m_c$ is the charm-quark mass and $p_T$ is the quarkonium transverse momentum.…
We study diffractive photoproduction of $J/\psi$ by taking the charm quark as a heavy quark. A description of nonperturbative effect related to $J/\psi$ can be made by using NRQCD. In the forward region of the kinematics, the interaction…
The production of gluons in a jet is considered in limited phase space, either with a cut in transverse momentum with respect to the jet axis $k_\perp<k_\perp^{cut}$ or with a cut in absolute momentum $|\vec{k} | <k^{cut}$. It is shown in…
This talk presents a review of recent results for quarkonium production at the LHC from ATLAS, CMS, LHCb, and ALICE. Production cross sections for $J/\psi$, $\psi(2S)$, and $\Upsilon(mS)$, and production ratios for $\chi_{c,bJ}$ are found…
A QCD factorization formalism was recently proposed for evaluating heavy quarkonium production at large $p_T$ at collider energies. With systematically calculated short-distance partonic hard parts and evolution kernels of fragmentation…
We extend to large transverse momentum pt an approach to quarkonium hadroproduction previously suggested for low pt. The dynamics involves a perturbative rescattering of the heavy quark pair off a comoving color field which originates from…
We explore the role of soft gluon exchange in heavy quarkonium production at large transverse momentum. We find uncanceled infrared poles at NNLO that are not matched by conventional NRQCD matrix elements. We show, however, that gauge…
In this work, we present a thorough analysis of scalar $P$-wave $\chi_{Q0}$, $Q=c,b$ quarkonia electromagnetic form factors for the $\gamma^* \gamma^* \to \chi_{Q0}$ couplings, as well as their hadroproduction observables in…
Quarkonium production at low transverse momentum in hadron collisions can be used to extract Transverse-Momentum-Dependent(TMD) gluon distribution functions, if TMD factorization holds there. We show that TMD factorization for the case of…
$J/\psi$ suppression/production is one of the main signature of quark-gluon plasma detection at RHIC and LHC. In order to study $j/\psi$ suppression/production in high energy heavy-ion collisions at RHIC and LHC, one needs to prove the…