Related papers: Resolution of the LHCb $\eta_c$ anomaly
Motivated by the increased precision expected from LHC Run 3, equally accurate theory predictions are mandatory. As supersymmetry mass limits increase, predictions can be improved by threshold resummation. We examine the effects of…
The $X(6900)$ resonance, originally discovered by the \texttt{LHCb} collaboration and later confirmed by both \texttt{ATLAS} and \texttt{CMS} experiments, has sparked broad interests in the fully-charmed tetraquark states. Relative to the…
To clarify the outstanding problem in charmonium production that existing theories cannot explain the observed cross sections of $\chi_{cJ}$ (J=0,1,2) and ratio $R_{\chi_c}=\sigma_{\chi_{c2}}/\sigma_{\chi_{c1}}\approx 0.75$ (in contrast to…
The dominant production process for heavy charged Higgs bosons at the LHC is the associated production with heavy quarks. We have calculated the next-to-leading-order supersymmetric QCD corrections to charged-Higgs production through the…
In this paper, we present the study of the hadroproduction rate of $h_c$ at next-to-leading order in $\alpha_s$ under the nonrelativisitic QCD (NRQCD) factorization framework, using long-distance matrix elements obtained from the fit of…
It is shown how nonrelativistic QCD (NRQCD) can be used to determine next-to-next-to-leading order relativistic and short-distance contributions to the total $t\bar t$ production cross section in the threshold regime at lepton colliders. A…
We analyze the exclusive charmonium $J/\psi+\eta_c$ pair production in $e^+e^-$ annihilation using the nonfactorized perturbative QCD and the light-front quark model(LFQM) that goes beyond the peaking approximation. We effectively include…
Within the framework of nonrelativistic-QCD (NRQCD) factorization, we perform a comprehensive investigation of the color singlet (CS) contribution to prompt $J/\psi$ pair production at the CERN Large Hadron Collider at next-to-leading order…
We present calculations of heavy quark and quarkonium production at CERN LEP2 in the k_T-factorization QCD approach. Both direct and resolved photon contribution are taken into account. The conservative error analisys is performed. The…
One of the most challenging open problems in heavy quarkonium physics is the double charm production in $e^+e^-$ annihilation at B factories. The measured cross section of $e^+ e^- \to J/\psi + \eta_c$ is much larger than leading order (LO)…
Heavy quarkonium production in the framework of the non-relativistic quantum chromodynamics and leading order of the parton Reggeization approach at the Tevatron and LHC is discussed. In this note, we compare our predictions for the…
Using new experimental data on photoproduction and $\Lambda_b^0$ decays, we derive constraints on the properties of the LHCb $P_c$ states. We conclude that $P_c(4312)$, $P_c(4380)$ and $P_c(4440)$ can be described as $\Sigma_c\bar D$,…
Recently we have proved the NRQCD factorization in heavy quarkonium production at high energy colliders at all orders in coupling constant. In this paper we extend this to non-equilibrium QCD and prove the NRQCD factorization in heavy…
We study J/\psi production at fixed-target energies, including the colour-octet production mechanisms predicted by NRQCD. In an earlier paper, we found that the octet components were crucial in understanding p_T-integrated forward (x_F > 0)…
We apply a Color Glass Condensate+Non-Relativistic QCD (CGC+NRQCD) framework to compute $J/\psi$ production in deuteron-nucleus collisions at RHIC and proton-nucleus collisions at the LHC. Our results match smoothly at high $p_\perp$ to a…
A global analysis of ATLAS and CMS measurements reveals that, at mid-rapidity, the directly-produced $\chi_{c1}$, $\chi_{c2}$ and J/$\psi$ mesons have differential cross sections of seemingly identical shapes, when presented as a function…
We study theoretical uncertainties in predicting top-quark pair-production near threshold at the LHC using the non-relativistic QCD framework. We include variations in the top-quark mass and width, the strong coupling $\alpha_s$,…
The asymmetry in the forward region production cross section of D^\pm is calculated using the heavy-quark recombination mechanism for pp collisions at 7 TeV. By suitable choices of four non-perturbative parameters, our calculated results…
We study the associated production of prompt $J/\psi$ mesons and $W$ or $Z$ bosons within the factorization approach of nonrelativistic QCD (NRQCD) at next-to-leading order in $\alpha_s$, via intermediate color singlet ${^3}S_1^{[1]}$ and…
We present predictions for top anti-top bottom anti-bottom production at the LHC in next-to-leading order QCD. The precise description of this background process is a prerequisite to observe associated top anti-top Higgs production in the…