Download Physics with p at the Future GSI Facility

Physics with p at the Future GSI Facility
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Physics program
Detector set-up
p
High Energy Storage Ring
HESR
e- cooler
High luminosity mode
Pmax = 1.5-15 GeV/c
Lmax < 2·1032 cm-2 s-1
Δ p/p ~ 10-4 (stochastic cooling)
detector
High resolution mode
Pmax = 1.5-8 GeV/c
Lmax 1031 cm-2 s-1
Δ p/p ~ 10-5 (electron cooling)
STORI’02
Carsten Schwarz
Physics program
Glueballs
Hybrids
Charmonium
spectroscopy
Medium modifications
of D mesons and
J/Ψ in nuclei
CP violation
STORI’02
Hypernuclei
Carsten Schwarz
James Ritman Univ. Giessen
STORI’02
Carsten Schwarz
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Charmonium
spectroscopy
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Charmonium gives information about QCD
confinement potential.
Many states are still missing.
pp: direct formation of all states.
HESR allows investigation of states above DD
threshold.
Cooled beams with Δp/p=10-4…10-5 allow high
precision scan of resonances.
Crystal Ball
e +e -
40 keV
STORI’02
Carsten Schwarz
Charmonium
spectroscopy
STORI’02
Crystal Ball
e +e -
Carsten Schwarz
Meson
Hybrid
Glueball
qq
qqg
ggg
Glueballs
Hybrids
Normal meson: 2 fermions
P = (-1)L+1
C = (-1)L+S
Excited glue:
bosonic degree of freedom
→ exotic quantum numbers
eg. JPC=1-+, 0--, 0+-, 2+-…
→ normal quantum numbers
STORI’02
Signal:
exotic quantum numbers:
partial wave analysis
normal quantum numbers:
model comparison (LGT)
mixing with normal mesons
charm sector: few resonances
with small widths
Carsten Schwarz
Glueballs
Hybrids
STORI’02
Carsten Schwarz
Mass modifications of mesons
Medium modifications
of D mesons and
J/Ψ in nuclei
Continuation of present GSI physics
FOPI, KAOS, HADES,
…HESR
Signal: medium modification of
production threshold,
resonance width
e.g. Ψ’, χ2
Absorption cross section of
J/Ψ in nuclei (ρ=ρ0).
STORI’02
pionic atoms
π
KAOS/FOPI
K
π25 MeV
π+
K+
100 MeV
HESR
D
vacuum
KD50 MeV ?
D+
nuclear medium
ρ = ρ0
Carsten Schwarz
Hypernuclei
K+K
Trigger
p
_
X
3 GeV/c
X-
X-(dss) p(uud)  L(uds)
L(uds)
study of L L interaction
secondary target
STORI’02
Carsten Schwarz
CP violation
in Hyperon decay
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p + p → Λ +Λ
↓ ↓
pπ- pπ+
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Measure decay asymmetry of angular
distribution of p relative to Λ-Hyperon
momentum.
Ip(θp) ~ 1+α cos(θp)
for Λ
Ip(θp) ~ 1+α cos(θp)
for Λ
CP conservation: α = - α
STORI’02
Signal for CP violation:
Theoretical prediction:
 
A
 10-4 ... 10-5
 
Experiment:
1010 reconstructed ΛΛ
L=2·1032 cm-2 s-1 → >1 year running
Carsten Schwarz
Angular acceptance
Formation of Ψ’ and decay in myons
electrons similar
→ calorimeter for
large angles.
Ψ’→μ+μ-
Ψ’→J/Ψ + X
↓
μ+μSTORI’02
Carsten Schwarz
HESR Detector
target spectrometer
forward spectrometer
Internal target
top view
Heavy charmed mesons decay in
light products with large pt.
Solenoid is important.
STORI’02
Carsten Schwarz
Particle identification
p+p → ΦΦ→ 4K
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s½ =3.6 GeV
Forward angles need π/K separation up to 3 GeV/c:
Backward: higher value of n.
STORI’02
Cherenkov n=1.02
Carsten Schwarz
STORI’02
Carsten Schwarz
Tracking, Micro Vertex Detector
2 mio. forward pixels
100 x 150 μm
7.2 mio. barrel pixels
50 x 300 μm
pellet pipe
beam pipe
Readout:
ASICs (ATLAS/CMS) 0.37% X0
or pixel one side – readout other side (TESLA)
STORI’02
Carsten Schwarz
MVD, single track resolution
σD0=51 μm
σZ0=82 μm
pp
8.5 GeV
2π+ 2π-
y
z
D0
Z0
x
STORI’02
Vertex resolution is sufficient for D-physics
c(D) = 314 μm, c(D0) = 124 μm
Carsten Schwarz
Target spectrometer,
momentum resolution
MVD
straw tubes
MDC
σM=
1.2%
???
pp(s = 4.4 GeV/c2)  J/f.
STORI’02
Carsten Schwarz
Particle identification
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PID from
– 00<Θ<50 hadronic calorimeter
– 50<Θ<220 Aerogel Cherenkov
Counters
– 220<Θ<1400 DIRC (BABAR@SLAC)
DIRC thickness: 0.19 X0
STORI’02
Carsten Schwarz
Particle
identification
STORI’02
pp(s = 4.4 GeV/c2)  J/f.
Carsten Schwarz
Calorimeter
22o
o
140
5o
PbWO4
Length = 17 X0
APD readout (in field)
σ(E) = 1.54% / E½ + 0.3% (PM)
pp  J/Ψ + η
γγ
STORI’02
Carsten Schwarz
Edep (GeV/c)
e±/π±
sep.
10
8
e+/-
6
4
π+
2
0
2
4
6
8
p (GeV/c)
π+ probability
10-3
electron/pion
separation  10-3
0
STORI’02
2
4
6
8
p (GeV/c)
Carsten Schwarz
Pellet target
1 mm
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STORI’02
Frozen hydrogen pellets 2040μm
Δx=±1 mm (±0.04o)
60 m/s
70000 pellets/sec.
1014-1016 atoms/cm2 (avg.)
Carsten Schwarz