R. Soltz for PHENIX - Quark Matter 2014 12014-05-20

Beam Energy Scan ResultsRon Soltz for PHENIX

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BES Motivation = CEP

• Limited theoretical guidance, need data2014-05-20

Baryon Chemical Potential B (GeV)

LQCD EoS and behavior of chiral susceptibility

Chiral effective models

?

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PHENIX Data and Measurements

• QM12– p0 suppression• PRL.109.152301

– J/psi• PRC.86.064901

– Flow, Fluctuations• This talk– Multiplicity– HBT Radii– Fluctuations

2014-05-20

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Multiplicity (quark) scaling10.1103/PhysRevC.89.044905

2014-05-20

Participant quark scaling works well √sNN= 62-200 GeV

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Nucleon Scaling

2014-05-20

Participant nucleon scaling works well √sNN <= 27 GeV

Implications for CEP and associated signatures?

see poster B-10 by Jeff Mitchel

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HBT BES Results

2014-05-20

see poster I-02 by Alex Mwai

- 3D Gaussian fits- Bertsch-Pratt coord.- LCMS (p1z+p2z=0)- Coulomb Corrected

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Ye Olde HBT formulae• Formerly used to understand dynamics before era of multi-stage models, assumptions too restrictive

2014-05-20

Chapman, Scotto, Heinz, PRL.74.4400 (95)

Makhlin, Sinyukov, ZPC.39.69 (88) (R2out-R2

side) sensitive to emission duration

empiricalfit just aseffective

Anticipate extended emission duration with 1st order transition

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mT scaling

• PHENIX and STAR consistent arxiv:1403.4972

• all radii linear– Ri=a+b/√mT

• Used to interpolate to common mT

2014-05-20

Rlong Rout Rside

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Geometric Scaling

2014-05-20

All radii linear in R, all slopes linear in 1/√mT

For 0-5% central R = σx/√2 = σy/√2

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HBT radii vs. √sNN

• PHENIX,STAR,ALICE data• mT=0.26 GeV interpolations

• Rlong decreasing with √sNN

• Rout,Rlong curvature differ from Rside

• construct ratios and differences

2014-05-20

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Measures of emission duration

• Non-monotonicity in Rout/Rside

• Subtract √2R to (over) estimate expansion2014-05-20

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Emission duration and expansion/lifetime

• Non-monotonicity magnified with (Rout)2 – (Rside)2

• Rside/Rlong indicative of expansion/lifetime2014-05-20

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Fluctuations in (s)PHENIX

2014-05-20

• Sensitive to correlation length, ξ [LQCD]Variance : 2 = <(N)2> ~ 2 [x(2)/x(1)]Skewness: S = <(N)3>/2 ~ 5.5 [x(3)/x(2)]Kurtosis: K 2 = <(N)4>/2-3 2~ 9 [x(4)/x(2)]

• Quark susc., x, LQCD calculate directly (μ=0)– for μ>0, higher order terms needed

• sPHENIX in 2019 (timing is of the essence)strong interest in BES-2 physicslarge acceptance detectors: VTX, Si, TPC

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BES2 sPHENIX (wishful) projections

2014-05-20

http://www.phenix.bnl.gov/plans.html - BES2 Whitepaper

PRL.105.022302

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Summary Conclusions• Nucleon Scaling below 27 GeV– implications for other CEP signatures ?!

• Non-monotonic behavior in Rout:Rside ratios and differences, Rside:Rlong (expansion/lifetime)– if location at softest EoS, peak height holds key to

transition order – consider change to nucleon dominated freeze-out – multi-stage modeling needed for HBT

• sPHENIX has strong interest in BES-2 physics2014-05-20

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Backup

• Starts here.

2014-05-20

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STAR Results

2014-05-20

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HBT radii vs. √sNN

• STAR arxiv:1403.4972

• evidence for 1st order behavior not readily apparent

• construct ratios and differences• interpolate to common mT

2014-05-20

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mT = 0.19 GeV

2014-05-20

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mT = 0.19 GeV

2014-05-20

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mT = 0.33 GeV

2014-05-20

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mT = 0.33 GeV

2014-05-20

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Net Charge Distributions

• Correlation length related to moments of conserved quantities including net charge• Correlation length should diverge at the critical point in the phase diagram

Net-charge (Nq = N+ - N- ) Net-charge (Nq = N+ - N- )

2014-05-20

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Net Charge Moments

They scale as correlation length

2014-05-20

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√sNN Dependence of Net Charge Fluctuations

• Neither K nor S vary with centrality at 7.7, 39, 62.4 and 200 GeV • Kurtosis vs energy is flat within errors• Skewness tracks UrQMD prediction• Analysis of data sets from √s = 19.6, 27 GeV still to be completed

UrQMD

2014-05-20