schwerionen- und hadronenphysik an und claudia höhne, gsi darmstadt khuk jahrestagung,...
TRANSCRIPT
Schwerionen- und
Hadronenphysik an
und
Claudia Höhne, GSI Darmstadt
KHuK Jahrestagung, 25./26.10.2007, GSI Darmstadt
• Einleitung
• GSI FOPI & HADES
• FAIR HADES & CBM
• Zusammenfassung & Ausblick
2 Claudia Höhne KHuK Jahrestagung, 2007, GSI
The QCD phase diagramaim of heavy ion physics
• explore the QCD phase diagram!• study hadronic properties at high baryon densities• chiral symmetry restoration?
FOPI & HADES @GSI
A+A collisions at < 2 GeV/nucleon
HADES@FAIR
A+A collisions at 2-10 GeV/nucleon
CBM@FAIR
A+A collisions at 10 – 45 GeV/nucleon
[A
nd
ron
ic e
t a
l. N
ucl
. P
hys
. A
77
2,
16
7 (
20
06
).
3 Claudia Höhne KHuK Jahrestagung, 2007, GSI
The SIS18 heavy ion regime
10 20 30
t [fm/c]
≈ 10 fm/c
Probing nuclear matter at “moderate" baryon density and temperature
A long life time of the dense system (up tp 10 fm/c)
The all-dominant presence of baryonic resonances
(“resonance matter”), N/Apart ≈ 10%
The sub-threshold production of Kaons and Vector Mesons: Multi-step processes confined to the dense phase
4 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Kaons in medium
Modified properties of hadrons in dense baryonic matter?→ mass, width, phase-space and angular distributions
in-medium kaon energy↔ equation of state in dense matter?
attractive K- N potential
repulsive K+ N potential
(yellow area: envelope of several microscopic calculations: all predict the same trend !)
5 Claudia Höhne KHuK Jahrestagung, 2007, GSI
FOPI – strangeness @ SIS
• Motivationhadronic properties in dense medium (1-3 0)?strangeness! (production close to threshold)→ sensitive probe!
• Kaons in mediumyields, phase space distributions, flow
• Strange Resonances Baryons! Excited hyperon *(1385)→ total strangeness, thermalisation?
• Exotica – kaonic bound states
IPNE Bucharest, Romania ITEP Moscow, RussiaCRIP/KFKI Budapest, Hungary Kurchatov Institute Moscow, RussiaLPC Clermont-Ferrand, France Korea University, Seoul, KoreaGSI Darmstadt, Germany IReS Strasbourg, France + IMP Lanzhou, ChinaFZ Rossendorf, Germany Univ. of Heidelberg, Germany + SMI Vienna, AustriaUniv. of Warsaw, Poland RBI Zagreb, Croatia + TUM, Munich, Germany
6 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Kaon – flow measurements
directed flow:
elliptic flow:
Sensitivity of collective flow to depth of kaon potential → U(K+) = + 20 MeV,
For K- no consistent description yet by transport models: HSD ↔ IQMD
Y.J.Kim (FOPI) Ni+Ni @ 1.93 AGeV
7 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Strange resonances* (
13
85
) s
ub
thre
sh
old
pro
du
cti
on
, X
. Lop
ez e
t al.
(FO
PI
coll
abor
atio
n), s
ubm
itte
d to
PR
L (
2007
)
• for investigation of total strangeness production baryons (!) are important!
→ test thermalization/ chemical equlibrium with statistical model
• short lived resonances (e.g. *) are expected to be also sensitive to dense medium!
• due to short lifetime * should probe finite density!
• Broadening of the width not yet observed (needs more statistics)
* in-medium:
Γ = 76 MeV at ρ = ρ0
Mean mass: attractive potential ≈ - 45 MeV at ρ0
* + (88 2%) = 39.4 MeV c = 5 fm
8 Claudia Höhne KHuK Jahrestagung, 2007, GSI
FOPI TOF upgrade completed!
FOPI – RPC detector: 4500 electronic channels, 6m2 active area
9 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Online performance from 1. experiment (Sep.2007)
K+ - identification by momentum – TOF analysis up to plab=1GeV/c
System time resolution estimate from fast pions: t = 100 ps
P (
GeV
/c)
v (cm/ns)t = tmeas – ttracking (ns)
p>0.5GeV/c
+
-
K+
p
10 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Summary of FOPI physics program (2008 – 2010)
2008 (S338): Heavy ion reactions
Ru + Ru @ 1.7 AGeV, 4 weeks Strange resonance production
Ni + Pb @ 2 AGeV, 2 weeks and flow K- - potential
2009 (S339): Pion induced reactions
+ LH2, C, Pb @ 1.7 GeV/c, 2 weeks Strangeness production
K- - potential at = 0
2010 (S349): Proton induced reactions
p + p @ 3 GeV, 2 weeks Search for ppK- - bound state
(accepted proposals by G-PAC)
11 Claudia Höhne KHuK Jahrestagung, 2007, GSI
In-medium properties of hadrons (electromagnetic-probes)
[Rapp, Wambach, Adv. Nucl. Phys. 25 (2000) 1, hep-ph/9909229]
• -meson couples to the medium, direct radiation from the early phase
• vector-meson dominance!
• vacuum lifetime 0 = 1.3 fm/c → dileptons = penetrating probe
• connection to chiral symmetry restoration?
pn
++
p
e+, μ+
e-, μ-
-meson spectral function
12 Claudia Höhne KHuK Jahrestagung, 2007, GSI
HADES
High Acceptance DiElectron Spectrometer
– Focus on the spectroscopy of vector mesons ()
– Consistent picture in pp, pA, A and AA reactions
– Supplemented by hadron spectroscopy, incl. K0
s, ,
Spectrometer with a …
– High geometric acceptance & invariant mass resolution
– High background rejection & rate capability, dedicated LVL2 trigger
Instrumental challenge!
→ e+e- rare probe:
1 e+e- decay from vector mesons per 1-10 Million reactions!
– Large background from conversion and 0-Dalitz decay
13 Claudia Höhne KHuK Jahrestagung, 2007, GSI
preliminary
Dileptons from C+C• excess of dilepton yield above cocktail!
• relative excess for 1 GeV/nucleon is larger than for 2 GeV/nucleon shape of relative excess similar
"cocktail A" = 0 + + (long lived)
[HA
DE
S,
PR
L 98
, 05
2301
(20
07)
]
14 Claudia Höhne KHuK Jahrestagung, 2007, GSI
• Quantitative analysis: deduce the absolute excess yield Yexc (beyond η), making use of the TAPS η data:
C + C 2 AGeV Phys. Rev. Lett. 98, 052302 (2007)
Yexc(2.0)/Yexc(1.0) = 2.3
± 0.6(stat) ± 1.0(sys)
Dileptons from C+C (II)
preliminary
• HADES confirms DLS!• excess (beyond η) scales like pions
→ importance of resonances!• discussions ongoing
15 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Comparison to DLS
DLS data (C+C, 1AGeV) confirmed by HADES!
preliminary
DLS Data:
R.J. Porter et al.: PRL 79(97)1229
• extrapolation of HADES data to DLS acceptance
• theory is challenged to explain data!
16 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Comparison HSD - HADES
• comparison of HADES data to HSD (new version including new isospin dependent Bremsstrahlung)
• lively discussions ongoing!
→ compare to p+p and p+n data!
[E. Bratkovskaya, priv. comm.]
HADES strategy:
• establish experimental "cocktail" of long and short lived e+e- pairs from pp and pn data
(s<sthres for production)
• study exclusive channels (e.g. +) in pp by missing mass spectroscopy
17 Claudia Höhne KHuK Jahrestagung, 2007, GSI
100% statistic analyzed :38877 signal pairs, 607 for M>150 MeV/c2
50% statistic analyzed:37800 signal pairs, 1230 for M>150 MeV/c2
Online spectrum (data from May 2007 )Preliminary not efficiency corrected spectrum
preliminary
preliminary
p+p, d+pe+e- X, 1.25 GeV
18 Claudia Höhne KHuK Jahrestagung, 2007, GSI
HADES schedule
Physics Runs in…
p, d, - induced A + A Status/Comment
2002 C + C 2 AGeV Published! (PRL)
2004 C + C 1 AGeV Analysis finished
2004 p + p 2.2 GeV Analysis finished
2005 Ar + KCl 1,75 AGeV Analysis ongoing
2006 p + p 1.25 GeV Analysis ongoing
2007 p + p 3.5 GeV
d + p 1.25 AGeV
… online results!
2008 p + A 3.5 GeV
2008/9 Upgrade RPC, DAQ
> 2008 + N, A Ni + Ni
Au + Au
planned
> 2014 Hades goes FAIR (8 AGeV)
"DLS puzzle"
elementary reactions!exclusive channels-beam!
chiral symmetry restoration for =0 in controled system
heavy systems!
19 Claudia Höhne KHuK Jahrestagung, 2007, GSI
HADES upgrade for heavier systems
• RPC (TOF with higher granularity, 80ps time resolution)
• DAQ (LVL1 rates beyond 30 KHz)
HADES at FAIR
20 Claudia Höhne KHuK Jahrestagung, 2007, GSI
High density matter at FAIR
[Bra
tkov
skay
a et
al.,
PR
C 6
9 (2
004)
054
907
]
UrQMD calculation of T, B as function of reaction time
(open symbols – nonequilibrium,
full symbols – appr. pressure equilibrium)
CBM • rare probes! (charm, dileptons) sensitive to medium• ... and bulk properties• aim for microscopic understanding
• higher energies (2-45 GeV/nucleon) → higher baryon densities, temperatures, energy densities created; but still over time span of 5-10 fm/c
• discovery potential: 1st order deconfinement phase transition? critical point? chiral phase transition?
21 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Charm production at threshold
[W. Cassing et al., Nucl. Phys. A 691 (2001) 753]
HSD simulations
• CBM will measure charm production at threshold
→ after primordial production, the survival and momentum of the charm quarks depends on the interactions with the dense and hot medium!
→ direct probe of the medium!
• do c and c quarks behave differently in baryon-rich matter?
• charmonium (cc) in hot and dense matter?
• relation to deconfinement?
22 Claudia Höhne KHuK Jahrestagung, 2007, GSI
CBM: Physics topics and Observables
Onset of chiral symmetry restoration at high B
• in-medium modifications of hadrons (,, e+e-(μ+μ-), D)
Deconfinement phase transition at high B • excitation function and flow of strangeness (K, , , , )• excitation function and flow of charm (J/ψ, ψ', D0, D, c)• charmonium suppression, sequential for J/ψ and ψ' ?
The equation-of-state at high B
• collective flow of identified hadrons• particle production at threshold energies (open charm)
QCD critical endpoint• excitation function of event-by-event fluctuations (K/π,...)
• mostly new measurements• CBM Physics Book (theory) in preparation
23 Claudia Höhne KHuK Jahrestagung, 2007, GSI
CBM collaborationRussia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. Petersburg
China:CCNU WuhanUSTC Hefei
Croatia:
University of SplitRBI, Zagreb
Portugal: LIP Coimbra
Romania: NIPNE Bucharest
Poland:Krakow Univ.Warsaw Univ.Silesia Univ. KatowiceNucl. Phys. Inst. Krakow
LIT, JINR DubnaMEPHI MoscowObninsk State Univ.PNPI GatchinaSINP, Moscow State Univ. St. Petersburg Polytec. U.
Ukraine: Shevchenko Univ. , Kiev
Univ. MünsterFZ RossendorfGSI Darmstadt
Czech Republic:CAS, RezTechn. Univ. Prague
France: IPHC StrasbourgGermany: Univ. Heidelberg, Phys. Inst.Univ. HD, Kirchhoff Inst. Univ. FrankfurtUniv. Mannheim
Hungaria:KFKI BudapestEötvös Univ. BudapestIndia:Aligarh Muslim Univ., AligarhIOP BhubaneswarPanjab Univ., ChandigarhUniv. Rajasthan, JaipurUniv. Jammu, JammuIIT KharagpurSAHA KolkataUniv Calcutta, KolkataVECC KolkataUniv. Kashmir, SrinagarBanaras Hindu Univ., Varanasi
Korea:Korea Univ. SeoulPusan National Univ.
Norway:Univ. Bergen
Kurchatov Inst. MoscowLHE, JINR DubnaLPP, JINR Dubna
51 institutions, > 400 members
Dresden, September 2007
Cyprus: Nikosia Univ.
24 Claudia Höhne KHuK Jahrestagung, 2007, GSI
The CBM experiment• tracking, momentum determination, vertex reconstruction: radiation hard silicon pixel/strip detectors (STS) in a magnetic dipole field
• hadron ID: TOF (& RICH)• photons, 0, : ECAL
• electron ID: RICH & TRD suppression 104
• PSD for event characterization• high speed DAQ and trigger (up to 10 MHz int. rates) → rare probes!
• muon ID: absorber + detector layer sandwich move out absorbers for hadron runs
MVD + STS
... measuring both channels would be the best crosscheck of results we can ever do!
25 Claudia Höhne KHuK Jahrestagung, 2007, GSI
STS tracking – heart of CBM
Challenge: high track density 600 charged particles in 25o
Task
• track reconstruction:
0.1 GeV/c < p 10-12 GeV/c
p/p ~ 1% (p=1 GeV/c)
• primary and secondary vertex reconstruction (resolution 50 m)
• V0 track pattern recognition
D+ → ++K- (c = 317 m)
D0 → K-+ (c = 124 m)
silicon pixel
and strip detectors
→ drives CBM layout!
26 Claudia Höhne KHuK Jahrestagung, 2007, GSI
STS and FEE R&D
Strip sensor development with CIS ErfurtFirst test sensor delivered spring 2007
Fast self-triggered readout chip n-XYTER in collaboration with DETNIprospect: CBM-XYTER
27 Claudia Höhne KHuK Jahrestagung, 2007, GSI
CbmRoot simulation framework• detector simulation (GEANT3)
• full event reconstruction: track reconstruction, add RICH, TRD and TOF info
• result from feasibility studies in the following: central Au+Au collisions at 25 AGeV beam energy (UrQMD)
28 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Open charm production• D0 → K-+ and D0 → K+- (c= 124 m), full event reconstruction
• <D0 + D0> = 1.5 ∙ 10-4 (central Au+Au collisions, 25 AGeV)
• first pixel detector (MAPS) at 10cm
• ~53 m secondary vertex resolution
• proton identification with TOF
1012 central Au+Au collisions, 25 AGeV
25 AGeVcentral AuAu
29 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Low mass vector mesons
invariant mass spectra
• electrons: pt > 0.2 GeV/c background dominated by physical sources (75%)
• muons: intrinsic p>1.5 GeV cut (125 cm Fe absorber), use TOF information
electrons: 200k events background 4 ∙108 events – signal 20k ev.All eAll e++ee--
Comb. bgComb. bgρρ ee++ee--
ee++ee--
φφ ee++ee--
ππ0 0 γγee++ee--
ππ00ee++ee--
ηη γγee++ee--
m = 14 MeV/c2 m = 11 MeV/c2
25 AGeVcentral AuAu
30 Claudia Höhne KHuK Jahrestagung, 2007, GSI
electrons: 2.4 ∙1010 events
J/ m = 38 MeV/c2
' m = 45 MeV/c2
J/ and '
invariant mass spectra
• electrons: p < 11 GeV/c, pt > 1 GeV, 1‰ interaction target (25 m Au)
• muons: 225 cm Fe absorber, no pt-cut
muons: 4 ∙108 events
J/ m = 22 MeV/c2
' m = 33 MeV/c2
25 AGeVcentral AuAu
31 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Summary & Outlook
• succesful investigation of hadronic matter at moderate densities (1-3 0)
• data on elementary interactions and serious theoretical effort essential!
• FOPI → sensitivity of kaons to dense medium demonstrated→ quantify medium modifications for strange hadrons
→ multi-strange clusters?
• HADES → "DLS puzzle" solved→ setup completed, production phase of high quality data→ broad program (e.g. p,A, Au+Au), upgrade and move to FAIR
• investigate high baryon density region of QCD phase diagram (deconfinement phase transition, chiral symmetry restoration)
• CBM → comprehensive investigation including rare probes (dileptons and charm) → detailed simulations, R&D ongoing
• complementary effort to LHC
32 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Backup
33 Claudia Höhne KHuK Jahrestagung, 2007, GSI
Vector Mesons: p+p, 3.5 GeV
May 2007May 2007, preliminary, online results! No final calibration/alignment!
Hadron analysis: missing mass Hadron analysis: missing mass techniquetechnique:
– pp 4-prong (+++-)-selection – <2% of statistics– pppp+0-
– ppppK+K-
ee++ee-- pair analysis pair analysis: not shifted! Preliminary
calibration… – Extra yield below VM pole
mass.
pp missing mass (GeV/c2)
yiel
d (
a.u
.)
η
pppp+0-
pp missing mass (GeV/c2)
Yie
l (a
.u.)
ppppK+K-
S/BS/B1010
11
0.5 1.0 0.5 1.0
MMeeee
Preliminary
Preliminary
PRELIMINARY