A technique to study the elastic and inelastic interaction of quarkonium with hadrons using femtoscopic correlations

On the Sum Rule Approach to Quarkonium-Hadron Interactions

We extend a recent sum rule calculation for inelastic quarkonium-hadron interactions to realistic parton distribution functions; we also include finite target-mass corrections. Both modifications are shown to have no significant effect on the resulting cross section behaviour but the performed analysis gives useful insights on the sum-rule approach in general.

A QCD Calculation of the Interaction of Quarkonium with Nuclei

The interaction of quarkonium with nuclei is studied in the $m_Q\rightarrow \infty$ limit of QCD, where the binding energy is found to be exactly computable. The dominant contribution to the interaction is from two-gluon operators. The forward matrix elements of these two-gluon operators can be determined from the QCD scale anomaly, and from deep inelastic scattering. We apply our results to the $Υ$ and $J/ψ$, treating the $\qqbar$ interaction as purely Coulombic. We find the $Υ$ binds in nuclear matter with a binding energy of a few $\mev$, while for the $J/ψ$ binding is of order 10 $\mev$. F…

Issues in Quarkonium Production

In this talk, I start with a brief introduction to Non-Relativistic QCD (NRQCD) and its applications to quarkonium physics. This theory has provided a consistent framework for the physics of quarkonia, in particular, the colour-octet Fock components predicted by NRQCD have important implications for the phenomenology of charmonium production in experiments. The applications of NRQCD to $J/ψ$ production at Tevatron and the tests of the theory in other experiments is discussed. In particular, the apparent disagreement of NRQCD with results from HERA on inelastic photoproduction of $J/ψ$ is discu…

Beyond The Colour-Singlet Model For Inelastic J/ψPhotoproduction

Bound-state corrections to $J/ψ$ production from almost real photons are calculated in the colour-singlet model. A systematic, gauge-invariant, theory of hard quarkonium processes is used upto $O(v^2)$, where $v$ is the relative velocity of the quarks. The internal structure of the meson is characterised by two parameters, $ε_B/M$ and $\nabla^2 ϕ(0)/M^2 ϕ(0)$, in addition to the usual wavefunction at the origin $ϕ(0)$. These parameters are constrained to be consistent with measured leptonic decay of the $J/ψ$ and hadronic and radiative decays of $η_c$.

Charmonium and bottomonium production in heavy-ion collisions

We review the present status in the theoretical and phenomenological understanding of charmonium and bottomonium production in heavy-ion collisions. We start by recapitulating the basic notion of "anomalous quarkonium suppression" in heavy-ion collisions and its recent amendments involving regeneration reactions. We then survey in some detail concepts and ingredients needed for a comprehensive approach to utilize heavy quarkonia as a probe of hot and dense matter. The theoretical discussion encompasses recent lattice QCD computations of quarkonium properties in the Quark-Gluon Plasma, their in…

利用关联数据对$\Lambda\bar\Lambda$和$p\bar\Lambda$相互作用的新约束

Novel constraints on $Λ\barΛ$ and $p\barΛ$ interactions using correlation data

本研究利用ALICE实验的关联数据，借助新型iCATS框架首次提取Λ-反Λ和质子-反Λ系统的散射参数，发现两系统湮灭特征不同，挑战了重子-反重子动力学普适性假设，验证了飞秒关联方法的有效性。

Nonperturbative Heavy-Quark Interactions in the QGP

We adopt a $T$-matrix approach to study quarkonium properties and heavy-quark transport in a Quark-Gluon Plasma. The $T$-matrix approach is well suited to implement potential scattering and thus provides a common framework for low-momentum transfer interactions in heavy-heavy and heavy-light quark systems. We assume that the underlying potentials can be estimated from the heavy-quark free energy computed in lattice QCD. We discuss constraints from vacuum spectroscopy, uncertainties arising from different choices of the potential, and the role of elastic and inelastic widths which are naturally…

Non-equilibrium charmonium regeneration in strongly coupled quark-gluon plasma

The evaluation of quarkonium regeneration in ultrarelativistic heavy-ion collisions (URHICs) requires the knowledge of the heavy-quark phase space distributions in the expanding quark-gluon plasma (QGP) fireball. We employ a semi-classical charmonium transport approach where regeneration processes explicitly account for the time-dependent spectra of charm quarks via Langevin simulations of their diffusion. The inelastic charmonium rates and charm-quark transport coefficients are computed from the same charm-medium interaction. The latter is modeled by perturbative rates, augmented with a $K$-f…