300 likes | 440 Views
Probing Properties of QCD Matter with Strange and Heavy Quarks. Huan Zhong Huang 黄焕中 Department of Physics and Astronomy University of California Los Angeles, CA 90095-1547 May 28-June 1, 2012, NN2012@San Antonio. Outline. Parton Degrees of Freedom from QCD Matter
E N D
Probing Properties of QCD Matter with Strange and Heavy Quarks Huan Zhong Huang 黄焕中 Department of Physics and Astronomy University of California Los Angeles, CA 90095-1547 May 28-June 1, 2012, NN2012@San Antonio
Outline • Parton Degrees of Freedom from QCD Matter • Parton Energy Loss and Jet-Medium Interaction • Heavy Ion Collisions as Exotic Factory Facility • Outlook
partonic hadronic A QCD Partonic Matter in Heavy Ion Collisions Properties of QCD Partonic Matter QCD Phases and Phase Boundary
Image the drop after a time-of-flight v distribution from BE condensate drop !!
Volcanic mediate pT – Spatter (clumps) An Equilibrated Partonic System L X W Use coalescence picture to study partons at the phase boundary 5
W and f are special • – (sss) state; m = 1672.45 MeV • f -- (ss) state; m = 1019.456 MeV Strange quark constituents produced in collisions No decay feeddown contributions Small hadronic re-scattering cross sections Messengers from quark-hadron phase boundary !
Strangeness from Bulk Partonic Matter RCP X L Constituent Quark Number Scaling -- Hadronization through quark clustering -- Effective DOF – constituent quarks quasi-hadrons at Tc ? Lattice QCD picture? W f(ss) 7
Parton PT Distributions at Hadronization If baryons of pT are mostly formed from coalescence of partons at pT/3 and mesons of pT are mostly formed from coalescence of partons at pT/2 • and f particles have no decay feeddown contribution ! • decay contribution is small These particles have small hadronic rescattering cross sections 8
Strange and down quark distributions s distribution harder than d distribution perhaps related to different s and d quarks in partonic evolution Independent Test – f/s should be consistent with s quark distribution Yes ! 9
Test on s/d Quark Ratios s/d quark ratios = W/X = X/L yes! but with large uncertainties due to decay feeddown corrections in L 10
Effective Parton Distribution in the QM Drop at Hadronization L Parton Spectroscopy at RHIC X W f Use particle emission to measure partonpT distribution and angular anisotropy (v2) in the dense parton drop !! More theoretical development – He, Fries and Rapp, Phys.Rev. C82 (2010) 034907
RHIC Beam Energy Scan Program RHIC BES data: 39.0, 11.5, 7.7 GeVAu+Au year 2010 27.0, 19.6 GeVAu+Au year 2011 -- Is there a transition from parton dominated matter to hadronic matter in the RHIC low energy region? -- Possible Structure of QCD phases – critical point? 12
phi meson v2 deviates from partonic picture @ 11.5 GeV • π+, K0S, p, Λ and Ξ- approximately follow one common curve • -mesons @ 11.5 GeV does not follow the trend of other hadrons. Mean deviation from the other distribution: 2.6 σ
W/f ratios @ 11.5 GeV also deviates from 39-200 GeV What is the collision energy where the deviation from partonic dominated matter becomes eminent? -- 2011 data from 19.6 and 27.0 GeVAu+Au collisions -- Perhaps more scan between 11.5 and 19.6 needed
Ratio of anti-Omega/Omega S quarks are pair-produced: why are there NET baryon numbers in W? Any dynamical process responsible for the baryon number transport? Direct Transport Through Gluon Junctions … W + K + K + K + (X) Note the anti-Lambda/Lambda ratio is much smaller where u/d quarks can carry the net quark number from baryon number stopping ! 15
Ratios of anti-L/L and anti-X/X at mid-rapidity Solid red: STAR BES Solid blue: STAR published Open blue: NA49 Baryon dynamics important at low beam energy collisions
Intriguing Features for Baryon Rich Matter Baryon and anti-baryon v2differences: ~10% at higher energiesincrease dramatically @ 7.7 and 11.5 GeV Chiral magnetic wave? Baryon transport? Hadronic potential?
pT Scales and Physical Processes RCP Three PT Regions: -- Fragmentation -- multi-parton dynamics (recombination or coalescence or …) -- Hydrodynamics (constituent quarks ? parton dynamics from gluons to constituent quarks? )
Jet – Medium Interactions Leading particle jet energy loss Jet and/or medium induced particle emission (trigger) Near-Side Away-Side Trig-hadron angular correlations Df = ftrig-fhadron
Conic Emission or V3 Initial Geometry More particles are emitted in a cone direction on the away-side !! Dynamics: Mach cone effect from supersonic jets passing thru the medium? Gluon radiation? parton scattering? Geometry: v3 initial state Use Heavy Quarks!! pTtrig= 2.5-4.0 GeV/c; pTasso= 1.0-2.5 GeV/c Au+Au Mark Horner (for STAR Collaboration): J. Phys. G: Nucl. Part. Phys. 34 (2007) S995
How does the dense medium couple to heavy quarks ? Does heavy quark participate in bulk collective flow ? thermalization of quarks/gluons Does heavy quark jet-medium interactiongenerate broad away-side emissions? Trigger on non-photonic electrons from heavy quark decays
Non-photonic electron -- hadron correlation 3 < pTtrig< 6 GeV/c & 0.15 < pTasso< 0.5 GeV/c dAu • Away side for d+Au is fit well by p+pPYTHIA • The Cu+Cu and Au+Au data cannot match the PYTHIA result – there is an away side broadening STAR Preliminary STAR Preliminary 0-20 % CuCu 0-20% AuAu
V2 and RAA are Related Precise value of v2 at pT> 6, 10 GeV/c ? RAA at pT > 10 GeV/c at RHIC should RAA approach unity at higher pT ? Future measurements will shed more lights on possible physical scenarios for parton energy loss dynamics ! Heavy Quarks will be special -- Lorentz g dependence on partonELoss on jet-medium interaction near-side vs away-side?
Features of Partonic Matter Central Au+Au Collisions at RHIC Bulk Partonic Matter -- 1) parton collectivity, multi- parton dynamics coalescence/recombination 2) v2 and pT distributions for effective quarks -- evolution from gluons – constituent quarks 3) Intriguing dynamics of baryon rich matter at low energy L X W 4) Major shift in DOF between 11-39 GeV?!
Remarks on Parton E Loss Parton Energy Loss Hadron PT Scale > 5-6 GeV/c Intrinsically a Dynamical Evolution System (path length?) ! -- Rapid Decrease of Energy Density with Evolution Time -- Even partons originated from the center of the hot/dense fireball may escape Theoretically Eloss calculations – dynamic issue simultaneous calculation of RAA and v2 at high pT !! Medium Response to Jets Plowing Through -- Heavy quark interactions with medium - non-photonic electron – hadron correlations - D – h correlations -- Separate Charm and Bottom energy loss – Heavy Flavor Tracker Upgrade– F. Videbaek’s talk!
Potential exotic particles/phenomena: penta-quark states (uudds, uudds!) di-baryons H – (L-L, uuddss) [W-W] (ssssss) strange quark matter meta-stable Parity/CP odd vacuum bubbles disoriented chiral condensate …… Discoveries from Unexpected Areas?! RHIC -- Frontier for bulk partonic matter formation (quark clustering and rapid hadronization) -- Factory for exotic particles/phenomena STAR’s capability has been enhanced greatly with recent upgrades !! 26
Search for di-hyperons and study hyperon-hyperon interactions from correlation measurement • The scattering length (a0) and the effective range (reff) with no, weak, medium, and strongcoupling to -N : a0 (fm) reff (fm) No coupling -2.42 -6.36 weak (Set.A) -2.47 -6.65 medium (Set.B) -2.98 -13.53 strong (Set.C) -2.27 -2.61 • Current fit parameters is consistent with non-existence of a strongly bound state of • 0-40% Au+Au @ 200 GeV STAR Preliminary Set A – Weak N coupling Set B – Medium N coupling Set C – Strong N coupling Fit A. Ohnishi and T. Furumoto
RHIC – a dedicated QCD Facility Having a great run! Even greater potential for future discoveries ! (Deconfinement Phase Transition) AA Exotic AA pA pp pp pA (CGC,EMC) (spin)
Volcanic high pT -- Strombolian eruption Volcanic mediate pT – Spatter (clumps) Volcanic low pT – Bulk matter flows Nucleus-Nucleus Collisions and Volcanic Eruption 30