https://web2.ph.utexas.edu/~cmarkert/matsui.pdf

$J/\psi$ Suppression by Quark-Gluon Plasma Formation

Critical phenomena and renormalization-group theory

A golden age for heavy-quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the B-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations at BESIII, the LHC, RHIC, FAIR, the Super Flavor and/or Tau-Charm factories, JLab, the ILC, and beyond. The list of newly found conventional states expanded to include h(c)(1P), chi(c2)(2P), B-c(+), and eta(b)(1S). In addition, the unexpected and still-fascinating X(3872) has been joined by more than a dozen other charmonium- and bottomonium-like "XYZ" states that appear to lie outside the quark model. Many of these still need experimental confirmation. The plethora of new states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c (c) over bar, b (b) over bar, and b (c) over bar bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. Lattice QCD has grown from a tool with computational possibilities to an industrial-strength effort now dependent more on insight and innovation than pure computational power. New effective field theories for the description of quarkonium in different regimes have been developed and brought to a high degree of sophistication, thus enabling precise and solid theoretical predictions. Many expected decays and transitions have either been measured with precision or for the first time, but the confusing patterns of decays, both above and below open-flavor thresholds, endure and have deepened. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.

/pdf/heavy-quarkonium-progress-puzzles-and-opportunities-2tru0l8jyp.pdf

Heavy quarkonium: progress, puzzles, and opportunities

http://cds.cern.ch/record/257993/files/9401310.pdf

QCD phenomenology based on a chiral effective Lagrangian

Neutron Stars 1: Equation of State and Structure

Quarks and gluons at high temperatures and densities

We investigate the Taylor expansion of the baryon number susceptibility, and hence, pressure, in a series in the baryon chemical potential (${\ensuremath{\mu}}_{B}$) through a lattice simulation with two flavors of light dynamical staggered quarks at a finer lattice cutoff $a=1/6T$. We determine the QCD cross over coupling at ${\ensuremath{\mu}}_{B}=0$. We find the radius of convergence of the series at various temperatures, and bound the location of the QCD critical point to be ${T}^{E}/{T}_{c}\ensuremath{\approx}0.94$ and ${\ensuremath{\mu}}_{B}^{E}/Tl1.8$. We also investigate the extrapolation of various susceptibilities and linkages to finite chemical potential.

QCD at finite chemical potential with six time slices

The momentum diffusion coefficient for heavy quarks is studied in a deconfined gluon plasma in the static approximation by investigating a correlation function of the color electric field using Monte Carlo techniques. The diffusion coefficient is extracted from the long-distance behavior of such a correlator. For temperatures ${T}_{c}lT\ensuremath{\lesssim}2{T}_{c}$, our nonperturbative estimate of the diffusion coefficient is found to be very different from the leading-order perturbation theory and is in the right ballpark to explain the heavy quark flow seen by the PHENIX Collaboration at the RHIC experiment.

Heavy quark momentum diffusion coefficient from lattice QCD

In this talk I present the logic behind, and examine the reliability of, estimates of the critical end point (CEP) of QCD using the Taylor expansion method.

https://theory.tifr.res.in/~sgupta/talks/08stariitb.pdf

On the critical end point of QCD

We summarize the theoretical description of charmonium and bottonium production in hadronic collisions and compare it to the available data from hadron-nucleon interactions. With the parameters of the theory established by these data, we obtain predictions for quarkonium production at RHIC and LHC energies.

Rajiv V. Gavai

Papers

Quarks and gluons at high temperatures and densities

QCD at finite chemical potential with six time slices

Heavy quark momentum diffusion coefficient from lattice QCD

On the critical end point of QCD

Quarkonium production in hadronic collisions