WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak,...

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WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai, A.M. Srivastava, G.C. Mishra, A.P. Mishra, A.K. Rath, P.K. Sahu Some formal talks and some ‘informal’ talks led to discussions and identifying problems

description

TOPICS DISCUSSED Contd. 6. Bound states above critical temperature 7. Higher order susceptibilities 8. Ads/CFT – QCD/QGP ? 9. Neutrino emission from crystalline color superconducting quark matter

Transcript of WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak,...

Page 1: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S.

Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai, A.M. Srivastava, G.C. Mishra, A.P. Mishra, A.K. Rath, P.K. Sahu

Some formal talks and some ‘informal’ talks led to discussions and identifying

problems

Page 2: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

TOPICS DISCUSSED1. Charmonium Suppression2. Jets3. Thermal and Direct Photons4. Hydrodynamic description of elliptic flow

Experimental data, unanswered questions Theory, Predictions Implementation and comparing techniques

5. Phi production at RHIC

Page 3: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

TOPICS DISCUSSED Contd.

6. Bound states above critical temperature

7. Higher order susceptibilities8. Ads/CFT – QCD/QGP ?9. Neutrino emission from crystalline

color superconducting quark matter

Page 4: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

1. Charmonium Suppression Talk by Luciano Ramello (INFN, Italy)

Results from NA50 and NA60 experiment. • Improved technique for background• J/Ψ absorption σ ~ 4.3 mb (p-A data only)

• earlier using S+U also, obtained ~7mb• Significant suppression in Pb+Pb and In+In• Suppression observed in RHIC• New models also including charm

recombination• No single model able to describe details of

the data on In+In and Pb+Pb• Recombination needed at RHIC

Page 5: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

2. Jets Identify jets using Fourier expansion (S.C.Phatak) Method based on analysis of pT weighted flow coeff.

To be tested with jets in events in relativistic heavy ion collision environment

Cone algorithm, kT algorithm (Kosower, Contreras) Some features that test goodness of the algorithms

• Infrared safe, Collinear safe, Independent of renormalization and factorization scale

• Amenable to comparison between theory and experiment

Suggested a problem for the LHC nvironment:• Study the dependence on the number, energy,

rapidity of the jets and the influence of the underlying event which may include mini jets

Page 6: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

3. Thermal and Direct Photons Discussion led by Terry Awes

NLO pQCD predictions describe direct photon p+p data well, at low √s where kT broadening has been introduced to explain.

Direct photons observed in Pb+Pb collisions at SPS energies (√s =17.GeV) can be described by • thermal emission (QGP+HG) with high initial

temperature (~300MeV). • additional kT broadening.

Direct photons at RHIC agree with NLO pQCD in p+p and at high pT in central Au+Au. Results for central Au+Au are consistent with thermal emission with initial T up to ~600MeV.

Other new techniques to extract low pT direct photon signal such as - HBT, - flow, and low mass electron pairs are being pursued.

Page 7: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

4. Hydrodynamic Description of Elliptic Flow

Discussion led by R. Bhalerao Ideal hydrodynamics does not quantitatively reproduce

pT-dependent flow of identified particles in centrality-selected bins

Estimated Mach, Knudsen and Reynolds numbers for RHIC and argued inadequacy of ideal hydrodynamics

Emphasised the need for Relativistic Dissipative Hydrodynamics…described the broad framework

“Three pT regions” of elliptic flow at RHIC Comparison of different techniques for different

experimental conditions (Standard Method, Lee-Yang zeroes)

Page 8: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

5. Phi production at RHIC Talk by Jajati Nayak

Production and evolution of strange particles Extract effective degrees of freedom that

characterize the coexisting phase and set a lower limit on Tc and geff

Overproduction takes place in mixed phase if Tc beyond 160 MeV

Page 9: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

6. Bound states above Tc

R. Ray, S. K. Ghosh & M. G. Mustafa

New lattice results indicate bound states above Tc

Spectral analysis for bound states J/, ’ etc. Heavier bound states survive up to larger T (~2Tc)

Lattice equation of state deviates from SB• Quarks and gluons not free

Pressure puzzle: resolved by putting colored b.s. (quasiparticles, coloured & colourless b.s.)

These have large σ…..leading to collective flow and low viscosity…..the sQGP Existence of binding potential

Tasks: Improvise on potential and equation of motion, improve determination of m, MD, s

Page 10: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

7. Higher Order Susceptibilities Discussion led by R.Gavai

Lattice results on quark number susceptibilities provide new insights

2 behaves like an order parameter

4 and 6 also behave drastically around Tc

pQCD and existing models failed to explain these results

need for improved models !!!

Model which can explain EOS as well as all

Page 11: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

8. Ads/CFT – QCD/QGP ? Discussion led by Balram

RHIC results indicate formation of “perfect liquid”

• η/S ~ 0.1 – 0.2, strongly coupled system, motivating description as hydrodynamic behaviour with low η

Need reliable estimates of transport coefficients in FT-QCD in strong coupling limit

AdS/CFT correspondence with N = 4 supersymmetric YM theory with FT in strong coupling limit may put a lower bound η/S ~ 0.1 (Liquid He ~9, Water ~380)

AdS/CFT QCD/QGP ? (coincidence or reality?)

Page 12: WG4 (QGP) REPORT Sudhir Raniwala, MG. Mustafa, S.K. Ghosh, R.S. Bahalerao, L. Ramello, Jajati Nayak, Rajarshi Ray, S.C. Phatak, V.K. Tiwari, R.V. Gavai,

9. Neutrino emission from crystalline color superconducting quark matter

P.Jaikumar and H. Mishra Identifying the proper ground state

Determine the excitation spectrum (considering simple case)

Use dispersion relation to compute neutrino emissivity and specific heat capacity

Determine the cooling rate and compare with data on observed Neutron Star temperature