beam energy scan results
DESCRIPTION
Beam Energy Scan Results. Ron Soltz for PHENIX. Baryon Chemical Potential B (GeV). BES Motivation = CEP. LQCD EoS and behavior of chiral susceptibility. Limited theoretical guidance, need data. ?. Chiral effective models. PHENIX Data and Measurements. QM12 p 0 suppression - PowerPoint PPT PresentationTRANSCRIPT
R. Soltz for PHENIX - Quark Matter 2014 12014-05-20
Beam Energy Scan ResultsRon Soltz for PHENIX
R. Soltz for PHENIX - Quark Matter 2014 2
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
?
R. Soltz for PHENIX - Quark Matter 2014 3
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