Investigating the transverse momentum dependent gluon Sivers function in quarkonium production at $pp$ colliders

重离子碰撞中夸克偶素集体性的研究

Investigating quarkonium collectivity in heavy-ion collisions

本研究利用2023年Run 3重离子碰撞数据，采用多种实验方法测量夸克偶素的流系数，以探究其集体性，为QGP中重夸克的产生与热化研究提供新约束，深化相关理论认知。

Quarkonium Physics at a Fixed-Target Experiment using the LHC Beams

We outline the many quarkonium-physics opportunities offered by a multi-purpose fixed-target experiment using the p and Pb LHC beams extracted by a bent crystal. This provides an integrated luminosity of 0.5 fb-1 per year on a typical 1cm-long target. Such an extraction mode does not alter the performance of the collider experiments at the LHC. With such a high luminosity, one can analyse quarkonium production in great details in pp, pd and pA collisions at sqrt(sNN)~115 GeV and at sqrt(sNN)~72 GeV in PbA collisions. In a typical pp (pA) run, the obtained quarkonium yields per unit of rapidity…

Investigating the heavy quarkonium radiative transitions with the effective Lagrangian method

In this work, we study the radiative decay of heavy quarkonium states by using the effective Lagrangian approach. Firstly, we construct the spin-breaking terms in the effective Lagrangian for the $nP\leftrightarrow mS$ transitions and determine the some of the coupling constants by fitting the experimental data. Our results show that in $χ_{cJ}$, $ψ(2S)$, $Υ(2S)$, and $Υ(3S)$ radiative decays, the spin-breaking effect is so small that can be ignored. Secondly, we investigate the radiative decay widths of the $c\bar{c}(1D)$ states and find the if $ψ(3770)$ is a pure $^3D_1$ state its radiative …

Transverse Single Spin Asymmetry in $J/ψ$ Production

We estimate transverse single spin asymmetry (TSSA) in electroproduction of $J/ψ$ for J-Lab and EIC energies. We present estimates of TSSAs in $J/ψ$ production within generalized parton model (GPM) using recent parametrizations of gluon Sivers function (GSF) and compare the results obtained using color singlet model (CSM) with those obtained using color evaporation model (CEM) of quarkonium production.

Prospects for quarkonium studies at the high-luminosity LHC

Prospects for quarkonium-production studies accessible during the upcoming high-luminosity phases of the CERN Large Hadron Collider operation after 2021 are reviewed. Current experimental and theoretical open issues in the field are assessed together with the potential for future studies in quarkonium-related physics. This will be possible through the exploitation of the huge data samples to be collected in proton-proton, proton-nucleus and nucleus-nucleus collisions, both in the collider and fixed-target modes. Such investigations include, among others, those of: (i) J/psi and Upsilon produce…

Heavy Quarkonium in the Quark Gluon Plasma from Effective Field Theories and Potentials

The measurements of heavy quarkonium suppression at RHIC and LHC urge theory to develop intuitive as well as quantitative methods for the description of $Q\bar{Q}$ melting in the quark-gluon plasma. Here I will present a brief sketch on the effective field theory strategies underlying the definition of the heavy quark static potential and report on two recent advances in the extraction and interpretation of such a potential. On the one side, progress has been made in obtaining its values from lattice QCD, which promises to make possible investigating its real and imaginary part non-perturbativ…

夸克极化和横向动量对强子碰撞中双夸克onium生产的影响

Quark polarization and transverse momentum effects on double quarkonium production in hadronic collisions

基于极化和横向动量影响，研究强子碰撞中双夸克onium生产，采用非相对论QCD论证和色单态模型，揭示夸克分布及Sivers函数的进一步验证可能。

Unpolarised TMD PDFs and FFs and the role of transverse momentum dependence in azimuthal spin asymmetries

In the TMD approach, the average transverse momentum of the unpolarised TMD PDFs and FFs is crucial not only to reproduce unpolarised cross sections and hadron multiplicities, but also for the understanding of azimuthal and spin asymmetries. Information on these transverse momenta is nowadays obtained mainly by fitting multiplicities data for SIDIS, where the intrinsic motion in the initial parton distributions and in the hadronisation process are strongly correlated and difficult to estimate separately without ambiguities. In this contribution we discuss the consequences of this correlation e…

Quarkonia production and polarization at the hadron colliders

This talk presents a review of recent results for quarkonium production at the LHC from ATLAS, CMS, LHCb, and ALICE. Production cross sections for $J/ψ$, $ψ(2S)$, and $Υ(mS)$, and production ratios for $χ_{c,bJ}$ are found to be in good agreement with predictions from non-relativistic QCD. In contrast, spin-alignment (polarization) measurements seem to disagree with all theoretical predictions. Some other production channels useful for investigating quarkonium hadroproduction mechanisms are also considered.

Hadro-quarkonium from Lattice QCD

The hadro-quarkonium picture [S. Dubinskiy and M.B. Voloshin, Phys. Lett. B 666, 344 (2008)] provides one possible interpretation for the pentaquark candidates with hidden charm, recently reported by the LHCb Collaboration, as well as for some of the charmonium-like "X,Y,Z" states. In this picture, a heavy quarkonium core resides within a light hadron giving rise to four- or five-quark/antiquark bound states. We test this scenario in the heavy quark limit by investigating the modification of the potential between a static quark-antiquark pair induced by the presence of a hadron. Our lattice QC…

粲偶素光生过程中的质子胶子引力形状因子

Gluon gravitational form factors of protons from charmonium photoproduction

本文通过全局拟合近阈J/ψ光生实验数据提取质子胶子引力形状因子，并结合夸克D项贡献研究质子力学性质，为胶子GFFs的QCD约束提供新视角。

电子-离子对撞机上 $J/ψ$ 加喷注产生的方位角关联

Azimuthal angular correlation of $J/ψ$ plus jet production at the electron-ion collider

本研究提出利用 EIC 上 $J/ψ$ 加喷注的方位角关联区分重夸克偶素的色单态与色八重态产生机制，并给出两类理论框架下的不对称性数值预言。

胶子碎裂函数的次领先阶近似分析

An analysis of the fragmentation function of gluon at next-to-leading order approximation

该研究基于DGLAP演化方程，利用拉普拉斯变换技术研究大横动量重夸克-反夸克束缚态的胶子碎裂函数演化，计算了两和四个夸克偶素态的数值解，并通过与文献结果比较准确确定了其在标度$μ$下的演化行为。