We show that we can reproduce all the features of bottomonium suppression in both proton-nucleus and nucleus-nucleus collisions at LHC energies in a comover-interaction picture. For each collisions system, we use the measured {\it relative} suppression of the excited $Υ$(2S) and $Υ$(3S) states to $Υ$(1S) by ATLAS and CMS to parametrise the scattering cross sections of all $S$- and $P$-wave bottomonia with the comoving particles created during the collisions. In addition to a single nonpertubative parameter, these cross sections depend on the momentum distribution of these comovers which we found to be the same for proton-nucleus and nucleus-nucleus collisions as well as for partonic and hadronic comovers. Moreover, we can also reproduce the {\it absolute} suppresion rates measured by ALICE, ATLAS, CMS and LHCb when the nuclear modifications of the parton densities are taken into account.
We show that we can reach a global and coherent description of bottomonium suppression in both proton-nucleus and nucleus-nucleus collisions at the LHC energies. The measured relative suppression of the excited bottomonium states as compared to their ground state allows us to constrain the scattering cross sections between the bottomonia and the comovers created during the collisions. Our result hints at a similar energy distribution of these comovers in the environment created by proton-nucleus and nucleus-nucleus collisions. Along the way of our study, we also update our knowledge for the bo…
In this proceedings contribution I review recent work which computes the suppression of bottomonium production in heavy-ion collisions using open quantum systems methods applied within the potential non-relativistic quantum chromodynamics (pNRQCD) effective field theory. I discuss how the computation of bottomonium suppression can be reduced to solving a Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) quantum master equation for the evolution of the b-bbar reduced density matrix. The open quantum systems approach used allows one to take into account the non-equilibrium dynamics and decoherence of…
The strong suppression of heavy quarkonia is a good indicator that one has generated a quark-gluon plasma (QGP) in an ultrarelativistic heavy ion collision. Recent advancements in first principles calculations of the heavy quark potential provide additional insight into this suppression and can be used to further pin down the in-medium properties of the QGP. Realistic 3+1d dissipative hydrodynamical models can be used to simulate the QGP and, with bottomonium as a probe, one can make inferences for the initial temperature of the QGP and other phenomenological parameters such as the shear visco…
Semiclassical treatment of bottomonium suppression and regeneration in $p+{\rm Pb}$ collisions
Kent State University（肯特州立大学）；Texas A&M University（德克萨斯农工大学）；Lawrence Livermore National Laboratory（劳伦斯利弗莫尔国家实验室）；University of California at Davis（加州大学戴维斯分校）
We compute the suppression and elliptic flow of bottomonium using real-time solutions to the Schrödinger equation with a realistic in-medium complex-valued potential. To model the initial production, we assume that, in the limit of heavy quark masses, the wave-function can be described by a lattice-smeared (Gaussian) Dirac delta wave-function. The resulting final-state quantum-mechanical overlaps provide the survival probability of all bottomonium eigenstates. Our results are in good agreement with available data for $R_{AA}$ as a function of $N_{\rm part}$ and $p_T$ collected at $\sqrt{s_{\rm…
We compute bottomonium suppression and elliptic flow within the pNRQCD effective field theory using an open quantum systems approach. For the hydrodynamical background, we use 2+1D MUSIC second-order viscous hydrodynamics with IP-Glasma initial conditions and evolve bottom/antibottom quantum wave packets in real time in these backgrounds. We find that the impact of fluctuating initial conditions is small when compared to results obtained using smooth initial conditions. Including the effect of fluctuating initial conditions, we find that the Upsilon(1S) integrated elliptic flow is v_2[1S] = 0.…
In the present article, we have studied the equation of state and dissociation temperature of bottomonium state by correcting the full Cornell potential in isotropic medium by employing the effective fugacity quasi-particle Debye mass. We had also calculated the bottomonium suppression in an expanding, dissipative strongly interacting QGP medium produced in relativistic heavy-ion collisions. Finally we compared our results with experimental data from RHIC 200GeV/nucleon Au-Au collisions, LHC 2.76 TeV/nucleon Pb-Pb, and LHC 5.02 TeV/nucleon Pb-Pb collisions as a function of number of participan…
The strong suppression of bottomonia production in ultra-relativistic heavy-ion collisions is a smoking gun for the creation of a deconfined quark-gluon plasma (QGP). In this proceedings contribution, I review recent work that aims to provide a more comprehensive and systematic understanding of bottomonium dynamics in the QGP through the use of pNRQCD and an open quantum systems approach. This approach allows one to evolve the heavy-quarkonium reduced density matrix, taking into account non-unitary effective Hamiltonian evolution of the wave-function and quantum jumps between different angular…
In this proceedings contribution I review recent progress concerning the suppression of bottomonium production in the quark-gluon plasma. Making use of open quantum system methods applied to potential non-relativistic quantum chromodynamics one can show that the dynamics of heavy-quarkonium bound states satisfying the scale hierarchy 1/a_0 >> pi T ~ m_D >> E obey a Lindblad equation whose solution provides the quantum evolution of the heavy-quarkonium reduced density matrix. To solve the resulting Lindblad equation we use a quantum trajectories algorithm which allows one to include all possibl…
We introduce a framework called Heavy Quarkonium Quantum Dynamics (HQQD) which can be used to compute the dynamical suppression of heavy quarkonia propagating in the quark-gluon plasma using real-time in-medium quantum evolution. Using HQQD we compute large sets of real-time solutions to the Schrödinger equation using a realistic in-medium complex-valued potential. We sample 2 million quarkonia wave packet trajectories and evolve them through the QGP using HQQD to obtain their survival probabilities. The computation is performed using three different HQQD model parameter sets in order to estim…
The suppression of bottomonia in ultrarelativistic heavy-ion collisions is a smoking gun for the production of a strongly interacting final state in ultrarelativistic heavy-ion collisions. Furthermore, these final state interactions are consistent with the production of a hot hydrodynamically expanding quark-gluon plasma with initial temperatures on the order of 600-700 MeV at LHC collision energies. Models which incorporate plasma screening and bound-state breakup based on high-temperature quantum chromodynamics are in good agreement with the centrality, transverse-momentum, and rapidity depe…
System-size dependence of bottomonium suppression from Pb-Pb to light-ion collisions
Technical University of Munich（慕尼黑工业大学）；Institute for Advanced Study, Technische Universität München（慕尼黑工业大学高等研究院）；Munich Data Science Institute, Technische Universität München（慕尼黑工业大学慕尼黑数据科学研究所）
We had been gradually working towards building a comprehensive quarkonia suppression formalism to explain all 3 dependencies of quarkonium suppression obtained from heavy-ion collision experiments. We present here the improved version of quarkonia suppression framework. It assumes bottomonia produced in the early stage which dissociates due to color screening, gluonic dissociation, and collisional damping in addition to the shadowing as an initial state effect. The QGP medium formed in the collisions is assumed to evolve under ($3+1$)-dimensional relativistic viscous hydrodynamics which is mod…
We solve the Lindblad equation describing the Brownian motion of a Coulombic heavy quark-antiquark pair in a strongly coupled quark-gluon plasma using the highly efficient Monte Carlo wave-function method. The Lindblad equation has been derived in the framework of pNRQCD and fully accounts for the quantum and non-Abelian nature of the system. The hydrodynamics of the plasma is realistically implemented through a 3+1D dissipative hydrodynamics code. We compute the bottomonium nuclear modification factor and compare with the most recent LHC data. The computation does not rely on any free paramet…
In this proceedings contribution, I review recent work that aims to provide a more comprehensive and systematic understanding of bottomonium dynamics in the quark-gluon plasma using an open quantum system (OQS) approach that is applied in the framework of the potential non-relativistic QCD (pNRQCD) effective field theory and coupled to realistic hydrodynamical backgrounds that have been tuned to soft hadron observables. I review how the computation of bottomonium suppression can be reduced to solving a Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) equation for the evolution of the b-bbar reduce…
The spectroscopic properties of heavy quarkonia are substantially different in the quark-gluon plasma (QGP) that is created in relativistic heavy-ion collisions as compared to the vacuum situation that can be tested in pp collisions at the same center-of-mass energy. In this article, a series of recent works about the dissociation of the Y(nS) and chi_b(nP) states in the hot QGP is summarized. Quarkonia dissociation occurs due to (1) screening of the real quark-antiquark potential, (2) collisional damping through the imaginary part of the potential, and (3) gluon-induced dissociation. In addit…
We estimate differential rapidity cross sections for $J/Ψ$, $Ψ(2S)$, $Υ(1S)$, $Υ(2S)$, and $Υ(3S)$ production; and $Ψ(2S)$ to $J/Ψ(1S)$, $Υ(3S)$ to $Υ(1S)$ suppression via Xe-Xe collisions at proton-proton energy $\equiv \sqrt{s_{pp}}$ =5.44 TeV. For the $Ψ(2S)$, $Υ(3S)$ states we use the mixed heavy quark hybrid theory, with these states being approximately 50\% standard and 50\% hybrid charmonium, bottomonium meson states.
Deconfined QCD matter in heavy-ion collisions has been a topic of paramount interest for many years. Quarkonia suppression in heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) experiments indicate the quark-gluon plasma (QGP) formation in such collisions. Recent experiments at LHC has given some indications of hot matter effect in asymmetric p$-$Pb nuclear collisions. Here, we employ a theoretical model to investigate the bottomonium suppression in Pb$-$Pb at $\sqrt{s_{NN}}=2.76$, $5.02$ TeV, and in p$-$Pb at $\sqrt{s_{NN}}=5.02$ TeV center-of-m…
The present article is the follow-up of our work Bottomonium suppression in quasi-particle model, where we have extended the study for charmonium states using quasi-particle model in terms of quasi-gluons and quasi quarks/antiquarks as a equation of state. By employing medium modification to a heavy quark potential thermodynamic observables {\em viz.} pressure, energy density, speed of sound etc. have been calculated which nicely fit with the lattice equation of state for gluon, massless and as well {\em massive} flavored plasma. For obtaining the thermodynamic observables we employed the deby…
Comprehensive study of $Υ$($n$S) production in Oxygen+Oxygen collisions at LHC
Kent State University（肯特州立大学）；Lawrence Livermore National Laboratory（劳伦斯利弗莫尔国家实验室）；University of California at Davis（加州大学戴维斯分校）；Texas A&M University（德克萨斯农工大学）
We report predictions for the suppression and elliptic flow of the $Υ(1S)$, $Υ(2S)$, and $Υ(3S)$ as a function of centrality and transverse momentum in ultra-relativistic heavy-ion collisions. We obtain our predictions by numerically solving a Lindblad equation for the evolution of the heavy-quarkonium reduced density matrix derived using potential nonrelativistic QCD and the formalism of open quantum systems. To numerically solve the Lindblad equation, we make use of a stochastic unraveling called the quantum trajectories algorithm. This unraveling allows us to solve the Lindblad evolution eq…
Charmonium dynamics in nucleus-nucleus collisions at SPS and FAIR energies
本文用HSD输运方法研究了SPS能区In+In和Pb+Pb反应中粲偶素的产生和抑制。对J/Psi抑制和Psi素数与J/Psi比值的输运计算结果与NA 50和NA 60合作的最新数据进行了比较。我们发现，对于所有的数据集，具有单个参数|M_0| ^2的转换吸收模型表现得最好。的“阈值方案”-在不同的假设熔化能量密度-产生一个合理的抑制J/PSI，但未能再现的PSI总理的J/PSI的比例为Pb+Pb在158 A GeV。预测金+金反应的轰击能量为25 A GeV的不同的情况下，这将允许一个明确的区别模型从实验方面在未来的FAIR设施。
Charmonium suppression in fixed target proton-nucleus collisions
Variable Energy Cyclotron Centre（变能回旋加速器中心）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；Bali Ram Bhagat College（巴里·拉姆·巴加特学院）；Indian Institute of Technology Goa（印度理工学院果阿分校）
