The PANDA Experiment at FAIR Marco Destefanis Università degli Studi di Torino Hadron Structure...
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Transcript of The PANDA Experiment at FAIR Marco Destefanis Università degli Studi di Torino Hadron Structure...
The PANDA ExperimentThe PANDA Experiment
at FAIRat FAIR
Marco Destefanis Università degli Studi di Torino
Hadron Structure 2013
Tatranské Matliare (Slovakia)June 30- July 04, 2013
for the PANDA Collaboration
OverviewOverview
• Physics topics @ PANDA
• Form Factors
• Drell-Yan process and background
• Hypernuclei
• PANDA spectrometer
• Summary
Primary beams:• Proton• Heavy Ions• Factor 100-1000 over present in intensity
Future GSI andFuture GSI andFacility for Antiproton Facility for Antiproton
and Ion Researchand Ion Research
Secondary Beams:• Radioactive beams• Antiprotons 3 - 30 GeV 1-2 107 /s
Storage and Cooler Rings:
• Radioactive beams• e – A collider
• 1011 stored and cooled
0.8 - 14.5 GeV antiprotons
High Energy Storage High Energy Storage RingRing
HESR
High res. mode: L = 1031 cm-2 s-1 p/p < 10-5
High lum. mode: L = 2·1032 cm-2 s-1 p/p < 10-4
Cooling: electron/stochastic
Pmax = 15 GeV/cLmax = 2·1032 cm-2 s-1
Ø < 100 mp/p < 10-5
internal target
Characteristics
1011 stored and cooled 0.8-15 GeV/c antiprotons
Antiproton powerAntiproton powerpbar beams can be cooled -> excellent resonance resolution
Preliminary expectation
The PANDA PhysicsThe PANDA Physics
• Confinement Why are there no free quarks?
• Hadron mass Where is the mass of the proton coming from?
• Are there other color neutral objects?
• What is the structure of the nucleon?
• What are the spin degrees of freedom?
J. Ritman, Status of PANDA, 8th International Workshop on Heavy Quarkonium 2011
• Meson spectroscopy*: • D mesons• charmonium • glueballs, hybrids, tetraquarks, molecules
• Charmed and multi-strange baryon spectroscopy*
• Electromagnetic processes (FF, pp→e+e-, pp→, Drell-Yan)
• Properties of single and double hypernuclei
• Properties of hadrons in nuclear matter
The PANDA PhysicsThe PANDA Physics
* Presented by V. Mochalov
The PANDA PotentialThe PANDA Potential
• All JPC allowed for qq are accessible in pp
T. Johansson, PANDA at FAIR, Excited QCD 2012, Peniche (Portugal)
Formation
• JPC not allowed for qq possible
Production
The experimental data set available is far from being complete. All strange hyperons and single charmed hyperons are energetically accessible in pp collisions at PANDA.
By comparing several reactionsinvolving different quark flavoursthe OZI rule and its possible violation, can be tested
In PANDA pp ΛΛ, ΛΞ, ΛΞ, ΞΞ , ΣΣ, ΩΩ, ΛcΛc, ΣcΣc, ΩcΩc
can be produced allowing the study of the dependences on spin observables.
QCD DynamicsQCD Dynamics
E. Tomasi-Gustafsson, M.P. Rekalo, PLB 504 (2001) 291
Generator:
|GM| = 22.5 (1 + q2 / 0.71)-2 (1 + q2 / 3.6)-1
= |GE|/|GM|
lower sensitivity @ higher q2
M. Sudol et al., EPJ A44 (2010) 373
p+pbar -> e+e- events p+pbar -> e+e- events generationgenerationL = 2 10 32 cm s → 2 fb-1 in 100 days
R=|GE|/|GM|
BaBAR
PS170PANDA sim
L = 2 10 32 cm s → 2 fb-1 in 100 days
M. Sudol et al., EPJ A44 (2010) 373
BABAR: B. Aubert et al. PRD 73 (2006) 012005
PS170: G. Bardin et al., NPB 411 (1994) 3
pQCD inspired: V. A. Matveev et al., LNC 7 (1973) 719 S. J. Brodsky et al., PRL 31 (1973) 1153
VDM: F. Iachello, PLB 43 (1973) 191
Extended VDM: E.L.Lomon, PRC 66 (2002) 045501
Individual determination of
|GE| and |GM| up to q2 14 (GeV/c)2 !!
PANDA Scenario: Expected PANDA Scenario: Expected Results Results
M. Sudol et al., EPJ A44 (2010) 373
L = 2 10 32 cm s → 2 fb-1 in 100 days
Absolute accessibleup to q2 28 (GeV/c)2
BABAR: B. Aubert et al. PRD 73 (2006) 012005E835: M. Andreotti et al., PLB 559 (2003) 20 M. Ambrogiani et al., PRD 60 (1999) 032002Fenice: A. Antonelli et al., NPB 517 (1998) 3PS170: G. Bardin et al., NPB 411 (1994) 3E760: T. A. Armstrong et al., PRD 56 (1997) 2509CLEO: T. K. Pedlar et al. , PRL 95 (2005) 261803DM1: B. Delcourt et al., PLB 86 (1979) 395DM2: D. Bisello et al., NPB 224 (1983) 379BES: M. Ablikim et al., PLB 630 (2005) 14
PANDA Scenario: Expected PANDA Scenario: Expected Results Results
E. Tomasi-Gustafsson, 12th International Conference on Nuclear Reaction Mechanisms, Villa Monastero, Varenna, Italy, 15 - 19 Jun 2009, pp.447, arXiv:0907.4442v1 [nucl-th]
L = 2 10 32 cm s → 2 fb-1 in 100 daysBABAR:
B. Aubert et al. PRD 73 (2006) 012005E835: M. Andreotti et al., PLB 559 (2003) 20 M. Ambrogiani et al., PRD 60 (1999) 032002Fenice: A. Antonelli et al., NPB 517 (1998) 3PS170: G. Bardin et al., NPB 411 (1994) 3E760: T. A. Armstrong et al., PRD 56 (1997) 2509CLEO: T. K. Pedlar et al. , PRL 95 (2005) 261803DM1: B. Delcourt et al., PLB 86 (1979) 395DM2: D. Bisello et al., NPB 224 (1983) 379BES: M. Ablikim et al., PLB 630 (2005) 14
Probing the Phragmèn-Lindelöf theorem:
PANDA Scenario: Asymptotic PANDA Scenario: Asymptotic BehavioursBehaviours
TMD: KTMD: KTT-dependent Parton Distributions-dependent Parton Distributions
Twist-2 PDFs )k,x(fkd)x(f T1T2
1
Distribution functions
Chirality
even odd
Twist-2
U
L
T
, h1,
Transversity
Boer-Mulders
Sivers
1hL1h
T1h
Tf1 Tg1
1f
1g
TMD PDF InvestigationTMD PDF Investigation
➠ Process SIDIS → convolution with FF
Drell-Yan → PDF only
pp annihilations: each valence quark can
contribute to the diagram
➠ Energies
@ FAIR unique energy range up to s~30 GeV2 with PANDA up to s~200 GeV2 with PAX
@ much higher energies → big contribution from sea-quarks
Drell-Yan ProcessDrell-Yan Process
• Drell-Yan: pp -> +-X
Collins-Soper frameCollins-Soper frame
Kinematics
x1,2 = mom fraction
of parton1,2
= x1 • x2 =
M2/s
xF = x1 - x2
Collins-Soper frame: Phys. Rev. D16 (1977) 2219.
SINGLE-POLARISED
UNPOLARISED
.
Drell-Yan Cross SectionDrell-Yan Cross Section
R.D. Tangerman and P.J. Mulders, Phys. Rev. D51, 3357-3372 (1995)
U = N(cos2φ>0)
D = N(cos2φ<0) DUDU
A
Asymmetry
CERN NA51 450 GeV/c
Fermilab E866 800
GeV/c
Di-Lepton ProductionDi-Lepton Production
pppp -> -> ll++ll--XX
A. Baldit et al., Phys. Lett. 332-B, 244 (1994)
R.S. Towell et al., Phys. Rev. D 64, 052002 (2001)
Phase space for Drell-Yan processesPhase space for Drell-Yan processes
x1,2 = mom fraction of parton1,2
= x1 • x2
xF = x1 - x2
= const: hyperbolaexF = const: diagonal
PAX @ HESR
symmetric HESR collider
1
1.5 GeV/c2 ≤ M ≤ 2.5 GeV/c2
PANDA
Drell-Yan Process and BackgroundDrell-Yan Process and Background
• Background studies: needed rejection factor of 107
• Drell-Yan: pp -> +-X
cross section 1 nb @ s = 30 GeV2
• Background: pp -> +-X, 2+2-X,……
cross section 20-30 b
m = 105 MeV/c2; m 145 MeV/c2
average primary pion pairs: 1.5
DY Asymmetries @ VertexDY Asymmetries @ VertexUNPOLARISED SINGLE-POLARISED
500KEv included in asymmetries
Acceptance
corrections crucial!
1 < qT < 2 GeV/c
2 < qT < 3 GeV/c
xP xP
xP
xP
xPxP
Physics Performance Report for PANDA arXiv:0903.3905
R = L·σ·ɛ
= 2·1032cm-2s-1 × x 0.8·10-33cm2× 0.33
= 0.05 s-1 ~ 130
Kev/month
Statistical errors for 500KEv generated
xP
)
)xP
xPPhysics Performance Report for PANDA arXiv:0903.3905
DY Asymmetries @ VertexDY Asymmetries @ Vertex
3 different systems contain double strangeness (S = -2)
Doubly strange hypernucleus:
Double hypernucleus:
Exotic hyperatom:
p
p
n
n
pp
n
n
p
e-
n pn Interactions: --nucleus: interplay between
the Coulomb and nuclear potential
Interactions: -N
Interactions:
From - hypernucleus to hypernucleus: after N
STORI’11 - F. Iazzi Politecnico di Torino&INFN
From hyperatom to - hypernucleus: absorption
Double Strange SystemsDouble Strange Systems
in the region close to the nucleus:
• Atomic orbitals overlap nucleus: Coulomb and Nuclear interaction shift the levels and broad them
• shift and width can be measured (only last level )
p
e-
np
n
-: M = 1.32132 [GeV/c2]; = 16.39.10-11 [s]; S = -2
• Stopped X- are captured into atomic (high) levels • X- undergoes an hyperatomic cascade• X-rays are emitted in the range 0÷1.2 MeV (12C) • Absorption from an atomic level into nucleus ends
the atomic cascade• Bohr radius in lowest levels(n=2,3): ≈ 15 – 25 [fm]
STORI’11 - F. Iazzi Politecnico di Torino&INFN
X-ray spectroscopy (from -) in the range: ≈ 0.1 – 1 [MeV]
No existing data!
Which Physics with Hyperatoms?Which Physics with Hyperatoms?
Physics (I): ΛΛ strong interaction (only possible in double hypernuclei)•Quarks: s-s interaction • YY potential: attractive/repulsive?
In One Boson Exchange mechanism: ΛΛ ΛΛ : only non strange, I =0 meson exchange (w,h...)• hyperfragments distribution: dependence on YY potential
Physics (II): ΛΛ weak interaction (only possible in double hypernuclei)Non Mesonic Hyperon Induced Decay:
• ΛΛ Λ n : (expected ΓΛn << Γfree ) (pΛ/N = 433 MeV/c)
• ΛΛ Σ-p : (expected ΓΣp << Γfree ) (pΣ/N = 321 MeV/c)
MeasurementsStrong interaction: • DBΛΛ(AZΛΛ) = BΛΛ(AZΛΛ ) - 2BΛ(A-1ZΛ) (from g spectroscopy)
Weak interaction: •momentum of p from decay•momentum of p from –p•momentum of – from , decay
p
p
n
n
STORI’11 - F. Iazzi Politecnico di Torino&INFNSeveral A data core of ΛΛ interaction
Formed by X- p ΛΛ reaction inside nucleus
Which Physics with Which Physics with ΛΛΛΛ Hypernuclei?Hypernuclei?
B
B.E.
A
The PANDA DetectorThe PANDA Detector
STT Detectors
Physics Performance Report for PANDA arXiv:0903.3905
The PANDA DetectorThe PANDA Detector
STT Detectors
Physics Performance Report for PANDA arXiv:0903.3905
Detector requirements:
• nearly 4 solid angle (partial wave analysis)
• high rate capability (2·107 annihilations/s)
• good PID (, e, , , K, p)
• momentum resolution (~1%)
• vertex info for D, K0S, (cτ =123 m for D0, p/m ≈
2)
• efficient trigger (e, , K, D, )
• no hardware trigger (raw data rate ~ TB/s)
MDT layoutMDT cross section
Muon Detector SystemMuon Detector System
Iarocci Tubes working in proportional mode
Ar+CO2 gas mixture
Prototype readyFE electronics in production
TDR for the PANDA Muon System, 2nd Draft (May 2011)
JINR - Dubna
Muon Detector Muon Detector LayoutLayout MDT’s Wires Strips
Barrel 2133 17064 49916
End Cap 618 4944 8911
Muon Filter 424 3392 6876
Forward Range System 576 4608 7128
Total 3751 30008 72831
Range System Range System PrototypePrototype
JINR - Dubna
DIRCDIRCMVDMVD
EMCEMC
Physics Performance Report for PANDA arXiv:0903.3905
STTSTT
PANDA PID Requirements:
particle identification essential for PANDA momentum range 200 MeV/c – 10 GeV/c Extreme high rates 2·107 Hz good particle separation (K-e)
different detectors needed for PID
Particle Particle IdentificationIdentification
All the details of the PANDA experimental program are reported in the “Physics Performance Report”.
Within this document, we present the results of detailed simulations performed to evaluate detector performance on many benchmark channels.
arXiv:0903.3905v1
PANDA Phyisics PANDA Phyisics Performance ReportPerformance Report