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RHIC HBT in a larger context. Zbigniew Chaj ę cki, OSU for the Experiment. Outline. HBT in Heavy-Ion Collisions at RHIC Multiplicity as universal scaling R(m T ) - direct probe of flow scenario Femtoscopy in p+p [reminder] - PowerPoint PPT Presentation
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Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 1
RHIC HBT RHIC HBT in a larger contextin a larger context
Zbigniew Chajęcki, OSU
for the Experiment
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 2
OutlineOutline
HBT in Heavy-Ion Collisions at RHIC
Multiplicity as universal scaling
R(mT) - direct probe of flow scenario
Femtoscopy in p+p [reminder]
mT scaling of HBT radii (AA/pp) [reminder]
Energy and Momentum Conservation Induced Correlations in p+p
STAR results from p+p (all fits)
world systematics : Rinv(N,mT), Ro,s,l(mT)
How different is pp from AA at the end?
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 3
Heavy ions at RHICHeavy ions at RHIC
Multidimensional analysis at RHIC
R(√SNN, mT, b, Npart, A, B, PID)
... but is there a scaling variable?
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 4
Multiplicity scaling of HBT radii at Multiplicity scaling of HBT radii at RHICRHIC
Radii scale with multiplicity
Lisa, Pratt, Soltz, Wiedemann, Ann.Rev.Nucl.Part.Sci. 55 (2005) 357-402
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 5
Flow is the most important bulk feature at RHIC mT-dependence of femtoscopy probes flow
the most directly quantitative agreement w/p-only observables
Au+Au@19.6GeV0-10% centrality
mmTT dependence of pion HBT dependence of pion HBT radiiradii
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 6
Femtoscopy - direct evidence of Femtoscopy - direct evidence of flowflow
Spectra
v2
HBT
Flow-dominated “Blast-wave”toy models capture main characteristicse.g. PRC70 044907 (2004)
KR
(fm
)
mT (GeV/c)
STAR PRL 91 262301 (2003)
space-momentum substructure mapped in detail
6
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 7
Id-pion correlations in p+pId-pion correlations in p+p
STAR preliminary
mT [GeV/c2] mT [GeV/c2]
p+p and A+A measured in thesame experiment
great opportunity to compare physics
what causes pT-dependence in p+p?
same cause as in A+A?
€
mT = kT2 + mπ
2
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 8
Femtoscopy in pp vs heavy Femtoscopy in pp vs heavy ionsions
pp, dAu, CuCu - STAR preliminary
Ratio of (AuAu, CuCu, dAu) HBT radii by ppHBT radii scale with pp
Scary coincidence or something deeper?
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 9
Z.Ch., Gutierrez, Lisa, Lopez-Noriega, [nucl-ex/0505009]
Pratt, Danielewicz [nucl-th/0501003]
Non-femto correlations / SH Non-femto correlations / SH representationrepresentation
d+Au: peripheral collisions
STAR preliminary
∑→→ ΔΔ
=binsall
iiiiimlml QCYQA
.
,cos
, ),cos|,(|),(4
|)(| φθφθπ
φθ
STAR preliminary
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 10
Decomposition of CF onto Spherical Decomposition of CF onto Spherical HarmonicsHarmonics
Au+Au: central collisions
C(Qout)
C(Qside)
C(Qlong)
∑→→ ΔΔ
=binsall
iiiiimlml QCYQA
.
,cos
, ),cos|,(|),(4
|)(| φθφθπ
φθ
Z.Ch., Gutierrez, Lisa, Lopez-Noriega, [nucl-ex/0505009]
Pratt, Danielewicz [nucl-th/0501003]
Qx<0.03 GeV/c
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 11
Non-femtoscopic correlations in Non-femtoscopic correlations in STARSTAR
Baseline problem is increasing
with decreasing multiplicity
STAR preliminary
N-dep. of non-femtoscopic correlations in p+p
STAR preliminary
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 12
EMCICs in other experimentsEMCICs in other experiments
CLEO PRD32 (1985) 2294
NA22, Z. Phys. C71 (1996) 405
Qx<0.04 GeV/cOPAL, Eur. Phys. J. C52 (2007) 787-803
Qx<0.2 GeV/cNA23, Z. Phys. C43 (1989) 341
E766, PRD 49 (1994) 4373M
ultip
licity
incr
ease
s
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 13
€
C(qo,qs,ql ) = C femto(qo,qs,ql ) ⋅F(qo,qs,ql )
€
F(qo,qs,ql ) = 1+ δo qo + δs qs + δl ql
€
F(qo,qs,ql ) = 1+ δoqo + δsqs + δlql
• MC simulations
• ‘ad-hoc’ parameterizations
• OPAL, NA22, …
Common approaches to „remove” Common approaches to „remove” non-femtoscopic correlationsnon-femtoscopic correlations
• An alternative explanation:Energy and Momentum Conservation Induced Correlations, Z.Ch. and Mike Lisa [ArXiv:0803.022, sub. to PRC]
• “zeta-beta” fit by STAR [parameterization of non-femtoscopic correlations in Alm’s]
€
C( p1, p2 ) ≅ C femto p1, p2( ) 1−1
N2
r p T ,1 ⋅
r p T,2
pT2
+pz,1 ⋅ pz,2
pz2
+E1 − E( ) ⋅ E2 − E( )
E 2 − E2
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
⎡
⎣
⎢ ⎢ ⎢
⎤
⎦
⎥ ⎥ ⎥
|Q| |Q|
|Q|
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 14
How do EMCICs look?How do EMCICs look?
mike lisa - Nuclear Physics & RIKEN Theory Seminar 8 Aug 2008 14
€
C(p1,p2) ≅1−1
N2
r p T,1 ⋅
r p T,2
pT2
+pz,1 ⋅pz,2
pz2
+E1 − E( ) ⋅ E 2 − E( )
E 2 − E2
⎛
⎝ ⎜ ⎜
⎞
⎠ ⎟ ⎟
€
Detailed shape depends on:
N, E , E 2 , pT2 , pZ
2
and kinematic cuts
GenBod calculations
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 15
EMCIC fit to STAR p+p dataEMCIC fit to STAR p+p data
15
λ = 0.38 ± 0.01 Ro = 0.65 ± 0.01 fmRs = 0.85 ± 0.02 fmRl = 1.42 ± 0.02 fm
λ = 0.38 ± 0.01 Ro = 0.65 ± 0.01 fmRs = 0.85 ± 0.02 fmRl = 1.42 ± 0.02 fm
15
λ = 0.69 ± 0.01 Ro = 0.98 ± 0.03 fmRs = 0.94 ± 0.02 fmRl = 1.46 ± 0.03 fm
λ = 0.69 ± 0.01 Ro = 0.98 ± 0.03 fmRs = 0.94 ± 0.02 fmRl = 1.46 ± 0.03 fm
N = 15<E> = 0.39 GeV<E2> = 0.19 GeV2
<pT2> = 0.5 GeV2
<pz2> = 0.25 GeV2
N = 15<E> = 0.39 GeV<E2> = 0.19 GeV2
<pT2> = 0.5 GeV2
<pz2> = 0.25 GeV2
STAR preliminary
€
C femto(qo,qs,ql ) = 1− λ( ) + λ ⋅Kc (qinv ) 1+ e−qo2 Ro
2 −qs2 Rs
2 −ql2 Rl
2
[ ]
standard fit
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 16
EMCIC fit to STAR p+p dataEMCIC fit to STAR p+p data
16
λ = 0.69 ± 0.01 Ro = 0.96 ± 0.04 fmRs = 0.98 ± 0.03 fmRl = 1.26 ± 0.02 fm
λ = 0.69 ± 0.01 Ro = 0.96 ± 0.04 fmRs = 0.98 ± 0.03 fmRl = 1.26 ± 0.02 fm
N = 10.3<E> = 0.61 GeV<E2> = 0.43 GeV2
<pT2> = 0.2 GeV2
<pz2> = 0.4 GeV2
N = 10.3<E> = 0.61 GeV<E2> = 0.43 GeV2
<pT2> = 0.2 GeV2
<pz2> = 0.4 GeV2
λ = 0.38 ± 0.01 Ro = 0.65 ± 0.01 fmRs = 0.85 ± 0.02 fmRl = 1.42 ± 0.02 fm
λ = 0.38 ± 0.01 Ro = 0.65 ± 0.01 fmRs = 0.85 ± 0.02 fmRl = 1.42 ± 0.02 fm
STAR preliminary
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 17
Various fits to STAR p+p dataVarious fits to STAR p+p data
STAR preliminary
STAR preliminary
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 18
mmTT scaling of HBT radii scaling of HBT radii
Various fits give different radii but mT scaling of HBT radii is preserved in all fits
p+p HBT looks like flow!
STAR preliminary
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 19
Multiplicity dependence in p+pMultiplicity dependence in p+p
200 GeV
Rin
v [
fm]
STAR preliminary
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 20
p+p vs heavy ions - R(N,mp+p vs heavy ions - R(N,mTT))STAR preliminary
Similar mT and multiplicity dependence of HBT radii in p+p and heavy ions in STAR
Is STAR p+p unique? Let’s look at world’s results on HBT in elementary particle collisions …
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 21
Femtoscopy in small systemsFemtoscopy in small systemsSystem √s [GeV] Facility Experiment
p-p 7.2 AGS E766
17 SPS NA49 -prelim
26 SPS NA23
27.4 SPS NA27
31-62 ISR AFS
44,62 ISR ABCDHW
200 SPS NA05
200 RHIC STAR
~1.9 LEAR CPLEAR
p-p 53 ISR AFS
200 SPS NA05
200-900 SPS UA1
1800 Tevatron E735
- 126 ISR AFS
h-p 21.7 SPS EHS/NA22
System √s[GeV] Facility Experiment
e+e- 3 SLAC Mark-II
10 CESR CLEO
29 SLAC TPC
34 TASSO
58 TRISTAN AMY
91 LEP OPAL
91 LEP L3
91 LEP DELPHI
91 LEP ALEPH
e-p HERA ZEUS
e-A HERA HERMES
R ≈ 0.5 - 1.5 fm
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 22
My first impression My first impression
€
C = 1+ λ exp −Rinv2 Qinv
2( )
€
C = 1+ λ exp −RG2 QG
2 + Q02τ 2
( )
€
C = 1+ λ2J1 qT RB( )
qT RB
⎡
⎣ ⎢ ⎢
⎤
⎦ ⎥ ⎥
2
1+ qocτ( )−1
€
C = 1+ λ exp −Rinv2 Qinv
2( )[ ] 1+ δ ⋅Qinv( )
€
C = 1+ λ exp −Rinv2 Qinv
2( )[ ] 1+ δ ⋅Qinv
2( )
€
C = 1+ λ exp −RG2 QG
2( )
€
C = 1+ λ2J1 qT RB( )
qT RB
⎛
⎝ ⎜ ⎜
⎞
⎠ ⎟ ⎟
2 ⎡
⎣
⎢ ⎢ ⎢
⎤
⎦
⎥ ⎥ ⎥1+ δB ⋅qT( )
€
C = 1+ λ exp −Re Qinv( )
€
C = 1+ λ1 exp −R12Q2
( ) + λ2 exp −R22Q2
( )
€
C = 1+ λ exp −Rinv2 Qinv
2( )[ ] 1+ ε ⋅Qinv + δ ⋅Qinv
2( )
€
C = 1+ λ2J1 qT RB( )
qT RB
⎡
⎣ ⎢ ⎢
⎤
⎦ ⎥ ⎥
2
1+ qocτ( )2 ⎛
⎝ ⎜
⎞ ⎠ ⎟−1
€
C = 1+ λ exp −Rinv2 Qinv
2( )[ ] 1+ δ ⋅Qinv
2( )
−1
€
C = 1+ λ2J1 qT RB( )
qT RB
⎡
⎣ ⎢ ⎢
⎤
⎦ ⎥ ⎥
2
1+ qLcτ( )−1
Can we do a direct comparison between experiments?
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 23
Parameterizations of 1D CF used in Parameterizations of 1D CF used in comparision b/w experimentscomparision b/w experiments
€
C = 1+ λ exp −Rinv2 Qinv
2( )
€
C = 1+ λ exp −RG2 QG
2 + Q02τ 2
( )
€
C = 1+ λ2J1 qT RB( )
qT RB
⎡
⎣ ⎢ ⎢
⎤
⎦ ⎥ ⎥
2
1+ qocτ( )−1
€
⎫
⎬
⎪ ⎪ ⎪
⎭
⎪ ⎪ ⎪
RB≈2·RG
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 24
• Femtoscopy similar in p+p as in Au+Au @ STAR• “World results” show both pT and N dependence!• EMCICs seen in small systems• differences observed in pT spectra consistent with EMCIC “distortion” of unchanging parent distribution (soft sector) - talk by Mike Lisa & arXiv:0807.3569Same physics in p+p as in Au+Au and the only difference
due to phase-space effects?possibilities:
1.spectra and HBT are insensitive to underlying physics (flow etc)
2.they are sensitive & the very different physics of A+A and p+p look coincidentally identical
3.they are sensitive, and driving physics is the same
24
SummarySummary
Z. Ch. - WPCF 2008, Krakow, Poland, Sep. 11-14 2008 25
www.femtoscopy.orgwww.femtoscopy.org Database of talks/proceedings on particle correlations and related topics
Femtoscopy.org in numbers• Meetings : 24 records• Speakers : 117 records• Talks : 248 records• Files : 295 records
25
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