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March 1, 2003University of Rochester - Graduate Student Days 1
Nuclear Physics at the University of Rochester
Steven ManlyGrad. Student DaysMarch 1, 2003
[email protected]://hertz.pas.rochester.edu/smanly/
Gammasphere
March 1, 2003University of Rochester - Graduate Student Days 2
Nuclear physics faculty• Theory
Prof. D. Koltun
• Experiment Prof. D. Cline Prof. S. Manly Prof. U. SchrÖder
(chemistry) Prof. F. Wolfs
Plus close connection and some collaboration with HEP
March 1, 2003University of Rochester - Graduate Student Days 3
Theoretical Nuclear Physics - Koltun
March 1, 2003University of Rochester - Graduate Student Days 4
Experimental Nuclear Physics• Cline:
– Coulomb excitation (gammasphere, chico)
– Direct reactions– exotic nuclei
• Manly:– Relativistic heavy ion collisions– Neutrinos– HEP {Zo(SLD), ILC}
• SchrÖder:– Dissipative collisions (superball)
• Wolfs:– Relativistic heavy ion collisions– Direct reactions (Apex, E917)
BNL (AGS and RHIC), MSU, Berkeley, Argonne, FNAL
March 1, 2003University of Rochester - Graduate Student Days 5
SchrÖder: Dissipative collisions, how nuclei fragment
Superball neutron calorimeter at National Superconducting Cyclotron Laboratory
March 1, 2003University of Rochester - Graduate Student Days 6
Cline: Coulomb excitation, gamma spectroscopy
March 1, 2003University of Rochester - Graduate Student Days 7
Gammasphere/CHICO (Lawrence Berkeley National Laboratory)
March 1, 2003University of Rochester - Graduate Student Days 8
Relativistic heavy ion physics with PHOBOS
Manly and Wolfs
March 1, 2003University of Rochester - Graduate Student Days 9
quarks leptonsGauge bosons
u c t
d s b
e
e
W, Z, , g, Gg
Hadrons
Baryons qqq qq mesons
p = uud
n = udd
K = us or us
= ud or ud
Strong interaction
nuclei
e
atomsElectromagnetic
interaction
March 1, 2003University of Rochester - Graduate Student Days 10
Quantum Chromodynamics - QCD
Gauge field carries the charge
q q
distance
energy density, temperature
rela
tive
stre
ngth
asymptotic freedom
qq qq
confinement
q q
March 1, 2003University of Rochester - Graduate Student Days 11
March 1, 2003University of Rochester - Graduate Student Days 12
March 1, 2003University of Rochester - Graduate Student Days 13
Relativistic heavy ions
•Two concentric superconducting magnet rings, 3.8 km circum.
•A-A (up to Au), p-A, p-p collisions, eventual polarized protons
•Funded by U.S. Dept. of Energy $616 million
•Construction began Jan. 1991, first collisions June 2000
•Annual operating cost $100 million
•Reached 10% of design luminosity in 2000 (1st physics run)!!
•AGS: fixed target, 4.8 GeV/nucleon pair
•SPS: fixed target, 17 GeV/nucleon pair
•RHIC: collider, 200 GeV/nucleon pair
•LHC: collider, 5.4 TeV/nucleon pair
March 1, 2003University of Rochester - Graduate Student Days 14
March 1, 2003University of Rochester - Graduate Student Days 15
March 1, 2003University of Rochester - Graduate Student Days 16
March 1, 2003University of Rochester - Graduate Student Days 17
Au-Au collision in the STAR detector
March 1, 2003University of Rochester - Graduate Student Days 18
The PHOBOS Detector (2001)
Ring Counters
Time of Flight
Spectrometer
• 4 Multiplicity Array
- Octagon, Vertex & Ring Counters• Mid-rapidity Spectrometer• TOF wall for high-momentum PID• Triggering
- Scintillator Paddles Counters- Zero Degree Calorimeter (ZDC)
Vertex
Octagon
ZDC
z
yx
Paddle Trigger Counter
Cerenkov
137000 silicon pad readout channels
1m
March 1, 2003University of Rochester - Graduate Student Days 19
Central Part of the Detector
(not to scale)
0.5m
March 1, 2003University of Rochester - Graduate Student Days 20
Au-Au event in the PHOBOS detector
March 1, 2003University of Rochester - Graduate Student Days 21
Signatures/observables
Energy density or number of participants
Measured value
•Strange particle enhancement and particle yields
•Temperature
•J/ and ’ production/suppression
•Vector meson masses and widths
•identical particle quantum correlations
•DCC - isospin fluctuations
•Flow of particles/energy (azimuthal asymmetries)
•jet quenching
Each variable has different experimental systematics and model dependences on extraction and interpretation
MUST CORRELATE VARIABLES
March 1, 2003University of Rochester - Graduate Student Days 22
Collision region is an extruded football/rugby ball shape
March 1, 2003University of Rochester - Graduate Student Days 23
Elliptic flow
12
63
9
12 3 6 9 12
Num
ber
of p
arti
cles
March 1, 2003University of Rochester - Graduate Student Days 24
12
63
9
Num
ber
of P
arti
cles
12 3 6 9 12
March 1, 2003University of Rochester - Graduate Student Days 25
Elliptic Flow at 130 GeV
(PHOBOS : Normalized Paddle Signal)
Hydrodynamic limit
STAR: PRL86 (2001) 402
PHOBOS preliminary
Hydrodynamic limit
STAR: PRL86 (2001) 402
PHOBOS preliminary
Thanks to M. Kaneta
March 1, 2003University of Rochester - Graduate Student Days 26
What does the future hold for ultrarelativistic heavy ion physics?
Long RHIC program - move from characterization to study, hopefully
• more data, esp. for J/
• species, energy changes
• build a self-consistent model
• tie in with CERN results
LHC - Pb beams at 5.4 TeV/nucleon pair
March 1, 2003University of Rochester - Graduate Student Days 27
March 1, 2003University of Rochester - Graduate Student Days 28
Isometric of PHENIX Detector
March 1, 2003University of Rochester - Graduate Student Days 29
Brahms experiment
From F.Videbœk
