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Rajiv V. Gavai

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I am Raja Ramanna Fellow in Physics Department, IISER Bhopal. My areas of research are i) Quantum Field Theory on Lattice, and under extreme temperatures and densities, ii) Hard probes of Quark-Gluon Plasma, iii) Heavy Ion Collisions and phase transitions in the Early Universe. I was in TIFR, Mumbai (1986-2019), Bielefeld, Germany (2019-20) and many other places such as BNL, New Yoek, Minn. U, CEA, Saclay, Tsukuba, Japan etc.

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Papers by Rajiv V. Gavai

Conundrums at Finite Density

Acta Physica Polonica B Proceedings Supplement, 2021

Extending the successes of lattice quantum chromodynamics(QCD) at zero as well as nonzero tempera... more Extending the successes of lattice quantum chromodynamics(QCD) at zero as well as nonzero temperatures to nonzero density is extremely desirable in view of the quest for the QCD phase diagram both theoretically and experimentally. It turns out though to give rise to some conundrums whose resolution may assist progress in this exciting but difficult area, and should therefore be sought actively.

Temperature dependence of the static quark diffusion coefficient

The energy loss pattern of a low momentum heavy quark in a deconfined quark-gluon plasma can be u... more The energy loss pattern of a low momentum heavy quark in a deconfined quark-gluon plasma can be understood in terms of a Langevin description. In thermal equilibrium, the motion can then be parametrized in terms of a single heavy quark momentum diffusion coefficient κ, which needs to be determined nonperturbatively. In this work, we study the temperature dependence of κ for a static quark in a gluonic plasma, with a particular emphasis on the temperature range of interest for heavy ion collision experiments.

Unravelling Medium Effects in Heavy Ion Collisions with Zeal

arXiv: High Energy Physics - Phenomenology, 2015

We propose a new observable, called zeal, to analyze events with jets in heavy ion collisions. Th... more We propose a new observable, called zeal, to analyze events with jets in heavy ion collisions. The observable measures how a thermal medium affects the multiplicity and distribution of energetic particles in a jet. Using few known models for energy loss and jet quenching, we demonstrate its capability to distinguish the physics of these models.

North-Holland, Amsterdam MONTE CARLO SIMULATION OF FERMIONIC FIELDS*

Monte Carlo simulation has become a prime tool in the study of nonperturbative phenomena in quant... more Monte Carlo simulation has become a prime tool in the study of nonperturbative phenomena in quantum field theory. The results for pure gauge fields have been spectacular, giving some of our first quantitative information on the solution of the SU(3) gauge theory of the strong interactions [1]. Despite the successes, progress has been considerably slower in attempts to extend these calculations to include fermionic fields. While numerical algorithms have in principle been found for simulating the dynamical quarks of the strong interactions, they are all extremely intensive in their demands for computer time [2-7]. This means that necessary checks for finite size effects, cutoff independence, and other sources of systematic error have been severely limited. I t is unlikely that the problem with fermions is merely one of not yet having found the optimal algorithm. The complexity of maintaining antisymmetry in the wave function of a filled Dirac sea requires detailed information on an e...

WHEPP6 QCD Working Group Report

ipht.cea.fr

This is the report of the QCD working group at WHEPP 6. Discussions and work on heavy ion collisi... more

∗ Speaker. c ○ Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence

We investigate the critical end point (CEP) of QCD with two flavours of light dynamical quarks at... more We investigate the critical end point (CEP) of QCD with two flavours of light dynamical quarks at finite lattice cutoff a = 1/4T using a Taylor expansion of the baryon number susceptibility. We find a strong volume dependence of the position of the critical end point. In the large volume limit we obtain T E /Tc ≈ 0.95 and µ E B /T E ≈ 1.1, where Tc is the cross over temperature at zero chemical potential, and T E and µ E B are the temperature and the baryon chemical potential at the critical end point. The small value of µ E B places it in the range of observability in energy scans at the RHIC. PoS(LAT2005)160

A Fresh Look at the Chemical Potential on the Lattice

Lattice techniques are the most reliable ones to investigate the QCD phase diagram in the tempera... more Lattice techniques are the most reliable ones to investigate the QCD phase diagram in the temperature-baryon density (chemical potential) plane. These techniques are, however, wellknown to be saddled with a variety of problems at nonzero density. I address here the old question of placing the baryonic (quark) chemical potential on the lattice and point out its important consequences for the current and future experimental searches of the QCD critical point.

The critical end point of QCD

We investigate the critical end point of QCD with two flavours of light dynamical quarks at finit... more We investigate the critical end point of QCD with two flavours of light dynamical quarks at finite lattice cutoff a=1/4T using a Taylor expansion of the baryon number susceptibility. We find a strong volume dependence of the position of the critical end point. In the large volume limit we obtain T^E/T_c \~ 0.95 and mu_B^E/T^E ~ 1.1, where T_c is the cross over temperature at zero chemical potential, and T^E and mu_B^E are the temperature and the baryon chemical potential at the critical end point. The small value of mu_B^E places it in the range of observability in energy scans at the RHIC.

Chemical potential on the lattice: Universal or Unique?

Lattice techniques are the most reliable ones to investigate non-perturbative aspects of quantum ... more Lattice techniques are the most reliable ones to investigate non-perturbative aspects of quantum chromodynamics (QCD) such as its phase diagram in the temperature-baryon density plane. They are, however, well-known to be beset with a variety of problems as one increases the density. We address here the old question of placing the baryonic (quark) chemical potential on the lattice. We point out that it may have important consequences for the current and future experimental searches of QCD critical point.

Sizing up the Nuclear Glue in J/ψ-production

Nuclear gluon densities are of great importance to the physics of relativistic heavy ion collisio... more Nuclear gluon densities are of great importance to the physics of relativistic heavy ion collisions, in particular, in assessing the origin of J/ψ-suppression. We describe our attempts to distinguish various models of the gluonic EMC-effect, using the existing J/ψ-production data in proton-nucleus collisions. We find that no model is capable of explaining all the features of the high precision E772 data although the overall trend suggests this to be more a matter of fine-tuning the models than the presence of new physical effects.

Lattice QCD predictions for shapes of event distributions along the freezeout curve in heavy-ion collisions

We present lattice QCD results along the freezeout curve of heavy-ion collisions for the ongoing ... more We present lattice QCD results along the freezeout curve of heavy-ion collisions for the ongoing RHIC energy scan as well as the LHC heavy-ion runs planned for this year. The skew and kurtosis of the event distribution of baryon number are positive at all energies studied, We predict three ratios of non-linear susceptibilities along the freezeout curve as functions of the colliding energy, Sqrt[S_NN]. They have smooth behaviour except in the vicinity of a critical point; this can have multiple benefits.

Phase Transitions in SO(3) Lattice Gauge Theory

The phase diagram of SO(3) lattice gauge theory is investigated by Monte Carlo techniques on both... more The phase diagram of SO(3) lattice gauge theory is investigated by Monte Carlo techniques on both symmetric and asymmetric lattices with a view (i) to understanding the relationship between the bulk transition and the deconfinement transition, and (ii) to resolving the current ambiguity about the nature of the high temperature phase. A number of tests, including an introduction of a magnetic field and measurement of different correlation functions in the phases with positive and negative values for the adjoint Polyakov line, lead to the conclusion that the two phases correspond to the same physical state. Studies on lattices of different sizes reveal only one phase transition for this theory on all of them and it appears to have a deconfining nature.

A Study of the Bulk Phase Transitions of the SU(2) Lattice Gauge Theory with Mixed Action

Using the finite size scaling theory, we re-examine the nature of the bulk phase transition in th... more Using the finite size scaling theory, we re-examine the nature of the bulk phase transition in the fundamental-adjoint coupling plane of the SU(2) lattice gauge theory at β_A = 1.25 where previous finite size scaling investigations of the deconfinement phase transition showed it to be of first order for temporal lattices with four sites. Our simulations on N^4 lattices with N=6, 8, 10, 12 and 16 show an absence of a first order bulk phase transition. We find the discontinuity in the average plaquette to decrease approximately linearly with N. Correspondingly, the plaquette susceptibility grows a lot slower with the 4-volume of the lattice than expected from a first order bulk phase transition.

Lattice Computations of Small-x Parton Distributions in a Model of Parton Densities in Very Large Nuclei

Using weak coupling methods McLerran and Venugopalan LV1 expressed the parton distributions in la... more Using weak coupling methods McLerran and Venugopalan LV1 expressed the parton distributions in large nuclei as correlation functions of a two dimensional Euclidean field theory. The theory has the dimensionful coupling g^2 μ , where μ^2∼ A^1/3 is the valence quark color charge squared per unit area. We use a lattice regularization to investigate these correlation functions both analytically and numerically for the simplified case of SU(2) gauge theory. In weak coupling (g^2μ L<< 5), where L is the transverse size of the nucleus, the numerical results agree with the analytic lattice weak coupling results. For g^2μ L>> 5, no solutions exist at O(a^4) where a is the lattice spacing. This suggests an ill-defined infrared behavior for the two dimensional theory. A recent proposal of McLerran et al. Kovner for an analytic solution of the classical problem is discussed briefly.

The phase transition in QCD with broken SU(2) flavour symmetry

We report the first investigation of the QCD transition temperature, T_c, for two flavours of sta... more We report the first investigation of the QCD transition temperature, T_c, for two flavours of staggered quarks with unequal masses at lattice spacings of 1/4T. On changing the u/d quark mass ratio in such a way that m(pi_0)^2/m(pi_+)^2 changes from 1 to 0.78, thus bracketing the physical value of this ratio, we find that T_c remains unchanged in units of both m_rho and Lambda_MSbar.

Quasi-static probes of the QCD plasma

Screening correlators and masses were studied at finite temperature in QCD with two flavours of d... more Screening correlators and masses were studied at finite temperature in QCD with two flavours of dynamical staggered quarks on a lattice. The spectrum of screening masses show a hierarchical approach to chiral symmetry restoration. Control of explicit chiral symmetry breaking through the quark mass was shown to be an important step to understanding this phenomenon. No sign of decays was found in the finite temperature scalar meson-like correlators in the confined phase.

Lattice QCD equation of state : improving the differential method

We propose an improvement of the differential method for the computation of the equation of state... more We propose an improvement of the differential method for the computation of the equation of state of QCD from lattice simulations. In contrast to the earlier differential method our technique yields positive pressure for all temperatures including in the transition region. Employing it on temporal lattices of 8, 10 and 12 sites and by extrapolating to zero lattice spacing we obtained the pressure, energy density, entropy density, specific heat and speed of sound in quenched QCD for 0.9 < T/Tc < 3. A comparison of our results is made with those from the dimensional reduction approach and a conformal symmetric theory at high-temperature.

Z2 Monopoles, Vortices, and the Deconfinement Transition in Mixed Action SU(2) Gauge Theory

Adding separate chemical potentials lambda and gamma for Z2 monopoles and vortices respectively i... more Adding separate chemical potentials lambda and gamma for Z2 monopoles and vortices respectively in the Villain form of the mixed fundamental-adjoint action for the SU(2) lattice gauge theory, we investigate their role in the interplay between the deconfinement and bulk phase transitions using Monte Carlo techniques. Setting lambda to be nonzero, we find that the line of deconfinement transitions is shifted in the coupling plane but it behaves curiously also like the bulk transition line for large enough adjoint coupling, as for lambda=0. In a narrow range of couplings, however, we find separate deconfinement and bulk phase transitions on the same lattice for nonzero and large lambda, suggesting the two to be indeed coincident in the region where a first order deconfinement phase transition is seen. In the limit of large lambda and gamma, we obtain only lines of second order deconfinement phase transitions, as expected from universality.

Thermodynamics of free Domain Wall fermions

Studying various thermodynamic quantities for the free domain wall fermions for both finite and i... more Studying various thermodynamic quantities for the free domain wall fermions for both finite and infinite fifth dimensional extent N_5, we find that the lattice corrections are minimum for N_T≥10 for both energy density and susceptibility, for its irrelevant parameter M in the range 1.45-1.50. The correction terms are, however, quite large for small lattice sizes of N_T≤8. We propose modifications of the domain wall operator, as well as the overlap operator, to reduce the finite cut-off effects to within 10 continuum results of the thermodynamic quantities for the currently used N_T=6-8 lattices. Incorporating chemical potential, we show that μ^2 divergences are absent for a large class of such domain wall fermion actions although the chiral symmetry is broken for μ≠0.

Results from Lattice QCD

I present our recent results on the critical end point in the \mu_B-T phase diagram of QCD with t... more I present our recent results on the critical end point in the \mu_B-T phase diagram of QCD with two flavours of light dynamical quarks and compare them with similar results from other groups. Implications for a possible energy scan at the RHIC are discussed. I also comment briefly on the new results of great relevance to heavy ion collisions from finite temperature lattice QCD simulations on speed of sound, specific heat and on the fate of J/\psi.

Conundrums at Finite Density

Acta Physica Polonica B Proceedings Supplement, 2021

Extending the successes of lattice quantum chromodynamics(QCD) at zero as well as nonzero tempera... more Extending the successes of lattice quantum chromodynamics(QCD) at zero as well as nonzero temperatures to nonzero density is extremely desirable in view of the quest for the QCD phase diagram both theoretically and experimentally. It turns out though to give rise to some conundrums whose resolution may assist progress in this exciting but difficult area, and should therefore be sought actively.

Temperature dependence of the static quark diffusion coefficient

The energy loss pattern of a low momentum heavy quark in a deconfined quark-gluon plasma can be u... more The energy loss pattern of a low momentum heavy quark in a deconfined quark-gluon plasma can be understood in terms of a Langevin description. In thermal equilibrium, the motion can then be parametrized in terms of a single heavy quark momentum diffusion coefficient κ, which needs to be determined nonperturbatively. In this work, we study the temperature dependence of κ for a static quark in a gluonic plasma, with a particular emphasis on the temperature range of interest for heavy ion collision experiments.

Unravelling Medium Effects in Heavy Ion Collisions with Zeal

arXiv: High Energy Physics - Phenomenology, 2015

We propose a new observable, called zeal, to analyze events with jets in heavy ion collisions. Th... more We propose a new observable, called zeal, to analyze events with jets in heavy ion collisions. The observable measures how a thermal medium affects the multiplicity and distribution of energetic particles in a jet. Using few known models for energy loss and jet quenching, we demonstrate its capability to distinguish the physics of these models.

North-Holland, Amsterdam MONTE CARLO SIMULATION OF FERMIONIC FIELDS*

Monte Carlo simulation has become a prime tool in the study of nonperturbative phenomena in quant... more Monte Carlo simulation has become a prime tool in the study of nonperturbative phenomena in quantum field theory. The results for pure gauge fields have been spectacular, giving some of our first quantitative information on the solution of the SU(3) gauge theory of the strong interactions [1]. Despite the successes, progress has been considerably slower in attempts to extend these calculations to include fermionic fields. While numerical algorithms have in principle been found for simulating the dynamical quarks of the strong interactions, they are all extremely intensive in their demands for computer time [2-7]. This means that necessary checks for finite size effects, cutoff independence, and other sources of systematic error have been severely limited. I t is unlikely that the problem with fermions is merely one of not yet having found the optimal algorithm. The complexity of maintaining antisymmetry in the wave function of a filled Dirac sea requires detailed information on an e...

WHEPP6 QCD Working Group Report

ipht.cea.fr

This is the report of the QCD working group at WHEPP 6. Discussions and work on heavy ion collisi... more

∗ Speaker. c ○ Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence

We investigate the critical end point (CEP) of QCD with two flavours of light dynamical quarks at... more We investigate the critical end point (CEP) of QCD with two flavours of light dynamical quarks at finite lattice cutoff a = 1/4T using a Taylor expansion of the baryon number susceptibility. We find a strong volume dependence of the position of the critical end point. In the large volume limit we obtain T E /Tc ≈ 0.95 and µ E B /T E ≈ 1.1, where Tc is the cross over temperature at zero chemical potential, and T E and µ E B are the temperature and the baryon chemical potential at the critical end point. The small value of µ E B places it in the range of observability in energy scans at the RHIC. PoS(LAT2005)160

A Fresh Look at the Chemical Potential on the Lattice

Lattice techniques are the most reliable ones to investigate the QCD phase diagram in the tempera... more Lattice techniques are the most reliable ones to investigate the QCD phase diagram in the temperature-baryon density (chemical potential) plane. These techniques are, however, wellknown to be saddled with a variety of problems at nonzero density. I address here the old question of placing the baryonic (quark) chemical potential on the lattice and point out its important consequences for the current and future experimental searches of the QCD critical point.

The critical end point of QCD

We investigate the critical end point of QCD with two flavours of light dynamical quarks at finit... more We investigate the critical end point of QCD with two flavours of light dynamical quarks at finite lattice cutoff a=1/4T using a Taylor expansion of the baryon number susceptibility. We find a strong volume dependence of the position of the critical end point. In the large volume limit we obtain T^E/T_c \~ 0.95 and mu_B^E/T^E ~ 1.1, where T_c is the cross over temperature at zero chemical potential, and T^E and mu_B^E are the temperature and the baryon chemical potential at the critical end point. The small value of mu_B^E places it in the range of observability in energy scans at the RHIC.

Chemical potential on the lattice: Universal or Unique?

Lattice techniques are the most reliable ones to investigate non-perturbative aspects of quantum ... more Lattice techniques are the most reliable ones to investigate non-perturbative aspects of quantum chromodynamics (QCD) such as its phase diagram in the temperature-baryon density plane. They are, however, well-known to be beset with a variety of problems as one increases the density. We address here the old question of placing the baryonic (quark) chemical potential on the lattice. We point out that it may have important consequences for the current and future experimental searches of QCD critical point.

Sizing up the Nuclear Glue in J/ψ-production

Nuclear gluon densities are of great importance to the physics of relativistic heavy ion collisio... more Nuclear gluon densities are of great importance to the physics of relativistic heavy ion collisions, in particular, in assessing the origin of J/ψ-suppression. We describe our attempts to distinguish various models of the gluonic EMC-effect, using the existing J/ψ-production data in proton-nucleus collisions. We find that no model is capable of explaining all the features of the high precision E772 data although the overall trend suggests this to be more a matter of fine-tuning the models than the presence of new physical effects.

Lattice QCD predictions for shapes of event distributions along the freezeout curve in heavy-ion collisions

We present lattice QCD results along the freezeout curve of heavy-ion collisions for the ongoing ... more We present lattice QCD results along the freezeout curve of heavy-ion collisions for the ongoing RHIC energy scan as well as the LHC heavy-ion runs planned for this year. The skew and kurtosis of the event distribution of baryon number are positive at all energies studied, We predict three ratios of non-linear susceptibilities along the freezeout curve as functions of the colliding energy, Sqrt[S_NN]. They have smooth behaviour except in the vicinity of a critical point; this can have multiple benefits.

Phase Transitions in SO(3) Lattice Gauge Theory

The phase diagram of SO(3) lattice gauge theory is investigated by Monte Carlo techniques on both... more The phase diagram of SO(3) lattice gauge theory is investigated by Monte Carlo techniques on both symmetric and asymmetric lattices with a view (i) to understanding the relationship between the bulk transition and the deconfinement transition, and (ii) to resolving the current ambiguity about the nature of the high temperature phase. A number of tests, including an introduction of a magnetic field and measurement of different correlation functions in the phases with positive and negative values for the adjoint Polyakov line, lead to the conclusion that the two phases correspond to the same physical state. Studies on lattices of different sizes reveal only one phase transition for this theory on all of them and it appears to have a deconfining nature.

A Study of the Bulk Phase Transitions of the SU(2) Lattice Gauge Theory with Mixed Action

Using the finite size scaling theory, we re-examine the nature of the bulk phase transition in th... more Using the finite size scaling theory, we re-examine the nature of the bulk phase transition in the fundamental-adjoint coupling plane of the SU(2) lattice gauge theory at β_A = 1.25 where previous finite size scaling investigations of the deconfinement phase transition showed it to be of first order for temporal lattices with four sites. Our simulations on N^4 lattices with N=6, 8, 10, 12 and 16 show an absence of a first order bulk phase transition. We find the discontinuity in the average plaquette to decrease approximately linearly with N. Correspondingly, the plaquette susceptibility grows a lot slower with the 4-volume of the lattice than expected from a first order bulk phase transition.

Lattice Computations of Small-x Parton Distributions in a Model of Parton Densities in Very Large Nuclei

Using weak coupling methods McLerran and Venugopalan LV1 expressed the parton distributions in la... more Using weak coupling methods McLerran and Venugopalan LV1 expressed the parton distributions in large nuclei as correlation functions of a two dimensional Euclidean field theory. The theory has the dimensionful coupling g^2 μ , where μ^2∼ A^1/3 is the valence quark color charge squared per unit area. We use a lattice regularization to investigate these correlation functions both analytically and numerically for the simplified case of SU(2) gauge theory. In weak coupling (g^2μ L<< 5), where L is the transverse size of the nucleus, the numerical results agree with the analytic lattice weak coupling results. For g^2μ L>> 5, no solutions exist at O(a^4) where a is the lattice spacing. This suggests an ill-defined infrared behavior for the two dimensional theory. A recent proposal of McLerran et al. Kovner for an analytic solution of the classical problem is discussed briefly.

The phase transition in QCD with broken SU(2) flavour symmetry

We report the first investigation of the QCD transition temperature, T_c, for two flavours of sta... more We report the first investigation of the QCD transition temperature, T_c, for two flavours of staggered quarks with unequal masses at lattice spacings of 1/4T. On changing the u/d quark mass ratio in such a way that m(pi_0)^2/m(pi_+)^2 changes from 1 to 0.78, thus bracketing the physical value of this ratio, we find that T_c remains unchanged in units of both m_rho and Lambda_MSbar.

Quasi-static probes of the QCD plasma

Screening correlators and masses were studied at finite temperature in QCD with two flavours of d... more Screening correlators and masses were studied at finite temperature in QCD with two flavours of dynamical staggered quarks on a lattice. The spectrum of screening masses show a hierarchical approach to chiral symmetry restoration. Control of explicit chiral symmetry breaking through the quark mass was shown to be an important step to understanding this phenomenon. No sign of decays was found in the finite temperature scalar meson-like correlators in the confined phase.

Lattice QCD equation of state : improving the differential method

We propose an improvement of the differential method for the computation of the equation of state... more We propose an improvement of the differential method for the computation of the equation of state of QCD from lattice simulations. In contrast to the earlier differential method our technique yields positive pressure for all temperatures including in the transition region. Employing it on temporal lattices of 8, 10 and 12 sites and by extrapolating to zero lattice spacing we obtained the pressure, energy density, entropy density, specific heat and speed of sound in quenched QCD for 0.9 < T/Tc < 3. A comparison of our results is made with those from the dimensional reduction approach and a conformal symmetric theory at high-temperature.

Z2 Monopoles, Vortices, and the Deconfinement Transition in Mixed Action SU(2) Gauge Theory

Adding separate chemical potentials lambda and gamma for Z2 monopoles and vortices respectively i... more Adding separate chemical potentials lambda and gamma for Z2 monopoles and vortices respectively in the Villain form of the mixed fundamental-adjoint action for the SU(2) lattice gauge theory, we investigate their role in the interplay between the deconfinement and bulk phase transitions using Monte Carlo techniques. Setting lambda to be nonzero, we find that the line of deconfinement transitions is shifted in the coupling plane but it behaves curiously also like the bulk transition line for large enough adjoint coupling, as for lambda=0. In a narrow range of couplings, however, we find separate deconfinement and bulk phase transitions on the same lattice for nonzero and large lambda, suggesting the two to be indeed coincident in the region where a first order deconfinement phase transition is seen. In the limit of large lambda and gamma, we obtain only lines of second order deconfinement phase transitions, as expected from universality.

Thermodynamics of free Domain Wall fermions

Studying various thermodynamic quantities for the free domain wall fermions for both finite and i... more Studying various thermodynamic quantities for the free domain wall fermions for both finite and infinite fifth dimensional extent N_5, we find that the lattice corrections are minimum for N_T≥10 for both energy density and susceptibility, for its irrelevant parameter M in the range 1.45-1.50. The correction terms are, however, quite large for small lattice sizes of N_T≤8. We propose modifications of the domain wall operator, as well as the overlap operator, to reduce the finite cut-off effects to within 10 continuum results of the thermodynamic quantities for the currently used N_T=6-8 lattices. Incorporating chemical potential, we show that μ^2 divergences are absent for a large class of such domain wall fermion actions although the chiral symmetry is broken for μ≠0.

Results from Lattice QCD

I present our recent results on the critical end point in the \mu_B-T phase diagram of QCD with t... more I present our recent results on the critical end point in the \mu_B-T phase diagram of QCD with two flavours of light dynamical quarks and compare them with similar results from other groups. Implications for a possible energy scan at the RHIC are discussed. I also comment briefly on the new results of great relevance to heavy ion collisions from finite temperature lattice QCD simulations on speed of sound, specific heat and on the fate of J/\psi.