Post on 29-Jan-2021
transcript
Egle Tomasi-Gustafsson
(on behalf of the Panda Collaboration) IRFU, SPhN-Saclay,
and
IN2P3 - IPN Orsay France
Egle Tomasi-Gustafsson
Anti-Proton
ANnihilation at
DArmstadt
@
Antiprotons physics with
Suzdal, 4-VI-2014 1
Quarks - 2014, Suzdal, Russia, 2-8 June
Egle Tomasi-Gustafsson
• How are color neutral
objects formed?
• Confinement: why free quarks are not observed?
• Origin of the hadron mass: the Higgs mechanism accounts for some percent of the hadron mass
• Establish existence and
properties of exotics, hybrids, glueballs
• Structure of the nucleon (charge, magnetic, spin distributions)
Suzdal, 4-VI-2014 2
Open questions in QCD (some..)
Egle Tomasi-Gustafsson
• From high intermediate energy complexity
Suzdal, 4-VI-2014 3
Hadron Physics
Quark model (Gell-Mann 1964) Hadrons are formed by quarks
which interact via gluons Baryons are hadrons formed by
3 quarks Mesons are hadrons formed by
quark-antiquark
Hadrons consist of bound systems of non-relativistic heavy constituents, coupling is small: non perturbative effects or higher order corrections can be neglected
10-15 10-17
0.2
0.8
PANDA (Antiproton
Anihilation at Darmstadt) :
hadron physics
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014
About 3000 scientists from around the world will carry out experiments to understand the fundamental structure of matter, to explore exotic forms of it and to find answers of how the universe evolved from its primordial state into what we see today. FAIR covering four major fields: allows to carry out several physics programs in parallel:
APPA Physics - Atomic, Plasma Physics and Applications
CBM - Compressed Baryonic Matter
NUSTAR Physics – Nuclear Structure,
Astrophysics and Reactions
http://www.fair-center.de
4
Egle Tomasi-Gustafsson
• Introduction • The antiproton probe
• Conclusions
• The PANDA detector • The experimental programme
• Hadron spectroscopy Charmonium spectroscopy Open charm Gluonic excitations
• Interaction of hadrons Hypernuclear Physics In medium modification of mesons Color transparency
• Hadron structure TDA, GDA, Drell Yan, Electromagnetic Proton Form Factors
Suzdal, 4-VI-2014
arXiv:0903.3905v1
5
Plan
Egle Tomasi-Gustafsson
• First accelerated at LEAR (1983) • 2-3 109 pbar per hour • Momentum range 100 MeV/c -2 GeV/c
• p/p≤ 0.8x10-3
• Polarized antiprotons at Fermilab
• Parity-violating (in flight) decay of anti-L0 hyperons P=45%, I(p)~ 104 s-1 (physics!) • Stern-Gerlach separation in inhomogeneous
magnetic field (too expensive) • Elastic scattering on C, LH2…
• and also channelling, penning traps, stochastic techniques, dynamic nuclear polarization
Suzdal, 4-VI-2014 6
Antiprotons
• Discovery of antiproton (Segré, Chamberlain,1955)
Egle Tomasi-Gustafsson
GSI – PAX
Unpolarized p beam
Polarized H target
Polarized p beam
F. Rathmann (Juelich)
Suzdal, 4-VI-2014 7
Egle Tomasi-Gustafsson
HESR
SIS 100/300
SIS18
RESR/CR
30 GeV Protons
50 MeV p-Linac
Cu Target
107 p/s @ 3 GeV
Collecting
Accumulating
Precooling
Accelerating
Cooling
100m
PANDA
pbar production •proton Linac 50 MeV •accelerate p in SIS18/SIS100 •produce pbar on target •collect pbar in CR, •cooling in RESR
http://www-panda.gsi.de/ http://www.fair-center.eu/
Parameters of HESR • Injection of pbar at 3.7 GeV • Slow synchrotron (1.5-14.5 GeV/c) • Storage ring for internal target operation • Luminosity up to L~ 2x1032 cm-2s-1
• Beam cooling (stochastic & electron) 8
Antiprotons at FAIR
Suzdal, 4-VI-2014
p
• Dedicated experiments in the past decades for
– Hadron spectroscopy
– Hadron structure
– Interaction of Hadrons
Egle Tomasi-Gustafsson
need of • Highest Rates • Good Resolution • Good Particle Identification
Fixed target experiment
and
Internal experiment
in HESR storage ring
(not interacting antiprotons
recirculate)
detector
Suzdal, 4-VI-2014 9
Hadron Physics with Antiprotons
Accelerator and Detector
are built and optimized together
for the best performances
• 4p acceptance • high rate capability (average
interaction rate 20 MHz) • excellent tracking capabilities,
momentum resolution 1% • Vertex reonstruction for D, Ks ,
hyperons • good PID ( e, m, p, K, p )
Čerenkov, ToF, dE/dx
• g detection 3 MeV- 10 GeV PWO crystal calorimeter
• flexible and modular design • continuous data acquisition, no hardware trigger, intelligent software trigger
Detector requirements
QCD bound states Hadrons in nuclear matter Electroweak physics Electromagnetic processes Hypernuclear Physics
Physic topics
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 10
p
detector
G.Boca GSI, Germany & U. Pavia, Italy
Solenoid Magnet (2T)
Dipole Magnet (1T)
Target System
Micro Vertex Detector
Straw Central Tracker
GEM Detectors
Straw Chambers
SciTil
Target System and Tracking Devices
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 11
p
detector
G.Boca GSI, Germany & U. Pavia, Italy
Disc DIRC Forward RICH
Forward ToF
Muon Detection
Barrel DIRC
Particle ID detectors
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 12
PWO Barrel EMC Forward EM Calorimeter
PWO Fwd Endcap
PWO Backward Endcap
G.Boca GSI, Germany & U. Pavia, Italy
detector Calorimetry
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 13
Egle Tomasi-Gustafsson
• Hadron spectroscopy
Charmonium spectroscopy Open charm Gluonic excitations
Suzdal, 4-VI-2014 14
Experimental Program
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 15
Recent findings at B-factories: X,Y,Z
Search for glueballs,hybrids…
Egle Tomasi-Gustafsson
Dalitz Plot
700000 events f0(1500)
M=1505±23 MeV
Γ=111±12 MeV
The lightest glueball? - No « flavor blind » decay - Mixing?
JPC = 0++
High statistics needed!
Suzdal, 4-VI-2014
•The resonance decays into two pseudoscalars:0+0-0- •The third pseudoscalar removes the excess energy
000ppppp
Crystal Barrel (LEAR)
05ppp
0'ppp0ppp
0p
LLKKpp
16
Lightest glueball: a scalar with JPC = 0++
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 17
Hadron spectroscopy at PANDA
JPC = 0--,0+-, 1-+, 2+-, 3-+
• hybrids
Gluon 1– (TM) 1+(TE)
1S0, 0–+ 1++ 1––
3S1, 1–– 0+- 0–+
1+- 1–+
2+- 2–+
Egle Tomasi-Gustafsson
Resonance production
JPC = 1- -
J = 0,2,.. C = +
J = 1,.. C = -
Formation: -> (precision physics)
Suzdal, 4-VI-2014 18
e+e− →ψ '→γχ1,2 →γ (γ J /ψ )→γγ e+e− Invariant mass reconstruction → detector resolution ≈ 10 MeV (radiative decay)
pp→χ1,2 →γ J /ψ →γ e+e− resonance scan: the precision depends on the beam resolution. • gluon-rich environment
• all qq allowed quantum numbers
• q-qbar annihilate into gluons
Egle Tomasi-Gustafsson
Appearance of a resonance in production mode and disappearance in formation mode sign its exotic nature
Very precise scan of a resonance in formation mode: depends on HESR beam momentum resolution p/p~10-5
Search for glueballs,hybrids…
Suzdal, 4-VI-2014
Mass resolution e+e- : 10 MeV FermiLab 240 keV HESR 30 keV
19
Egle Tomasi-
Gustafsson
About pp cross sections
PANDA
Crystal Barrel E760/E835
Obelix
PS185
Jetset
[mb]
Suzdal, 4-VI-2014 20
Source: PDG
pp cross sections
•Cross sections expectations for – glueballs and light hybrids
• rates comparable to light hadrons
– charmed hybrids and molecules
• rates comparable to charmed hadrons
100 mb
10 mb
1 mb
100 μb
10 μb
1 μb
100 nb
10 nb
1 nb
ηc
χc0
χc2
ηcπ0
Hybrids
Glueballs
X(3872)
Suzdal, 4-VI-2014
21 Egle Tomasi-Gustafsson
[mb]
[nb]
[mb]
Egle Tomasi-Gustafsson
Panda will have: - Better luminosity - Better beam momentum resolution - Better detector (coverage, PID,magnetic field..)
Suzdal, 4-VI-2014
Antiproton facilities
22
(Low energy beams)
The detector
Interaction of hadrons
Hypernuclear Physics In medium modification of mesons Color transparency
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 23
Experimental Program
Egle Tomasi-Gustafsson
Suzdal, 4-VI-2014 24
U. Wiedner
Hypernuclei: replacing u or d with s-quark 3rd dimension: strangeness
35 L-hypernuclei, few LL-hypernuclei known no antihyperons in nuclei observed search for H-dibaryon: uuddss
New approach: Capture and conversion: 5-10% Double mesonic decay: 10% Data taking efficiency: 50% Several tens of LL-hypernuclei/day expected
•Hyperon is not limited by the Pauli principle •Baryon-baryon interactions: *L−N interaction: short L lifetime * L-L scattering : exp. Impossible
•Shell model parameters •Weak decays: LN ->NN, LL->NN
25 Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson
Double Hypernuclei
capture
of Ξ- in
secondary
target:
atomic
transition
Egle Tomasi-Gustafsson
• Hadron structure
Electromagnetic Form Factors TDA, GDA,Drell Yan
Suzdal, 4-VI-2014 26
Experimental Program
Suzdal, 4-VI-2014 27
_ _
q20
e-
e+ p
p
q2 q2=4mp2
Time-Like
FFs are complex Space-like
FFs are real Un
ph
ysic
al
reg
ion
GE=GM
GE(0)=1
GM(0)=mp
Asymptotics
- QCD
- analyticity
p+p ↔ e++e- e+p e+p
p+
p ↔
e++
e- +
p0
Egle Tomasi-Gustafsson
Hadron Electromagnetic Form factors )2q(
2F
M2
qi)2q(
1F
m
mgm
Egle Tomasi-Gustafsson 28
The polarization induces a term in the cross section proportional to GE GM
Polarized beam and target or
polarized beam and recoil proton polarization Suzdal, 4-VI-2014
The polarization method (theory:1967)
Egle Tomasi-Gustafsson 29
The simultaneous measurement of Pt and Pl reduces the systematic errors
Suzdal, 4-VI-2014
C. Perdrisat et al, JLab-GEp
collaboration
The polarization method (exp: 2000)
A.I. Akhiezer and M.P. Rekalo, 1967
Jlab-GEp collaboration 1) "standard" dipole function
for the nucleon magnetic FFs GMp and GMn
2) linear deviation from the dipole function for the electric proton FF Gep
3) QCD scaling not reached
3) Zero crossing of Gep?
4) contradiction between polarized and unpolarized measurements
Suzdal, 4-VI-2014 30 Egle Tomasi-Gustafsson
A.J.R. Puckett et al, PRL (2010), PRC (2012)
Polarization experiments
Egle Tomasi-Gustafsson 31
•Some models (IJL 73, Di-quark, soliton..) predicted such behavior before the data appeared
• Simultaneous description of the four nucleon form factors...
• ...in the space-like and in the time-like regions
• Consequences for the light ions description
• When pQCD starts to apply?
• Source of the discrepancy
BUT
Suzdal, 4-VI-2014
Issues
Time-like observables: | GE| 2 and | GM| 2 .
Suzdal, 4-VI-2014 32
As in SL region: - Dependence on q2 contained in FFs - Even dependence on cos2q (1g exchange) - No dependence on sign of FFs - Enhancement of magnetic term but TL form factors are complex!
A. Zichichi, S. M. Berman, N. Cabibbo, R. Gatto, Il Nuovo Cimento XXIV, 170 (1962)
B. Bilenkii, C. Giunti, V. Wataghin, Z. Phys. C 59, 475 (1993).
G. Gakh, E.T-G., Nucl. Phys. A761,120 (2005).
Egle Tomasi-Gustafsson
arXiv:0810.4245 DAPNIA-04-10
Individual determination of |GE| and |GM|
pQCD
VMD
F. Iachello et al., Phys. Rev. C 69 (2004) 055204
E. L. Lomon, Phys. Rev. C 66 (2002) 045501 V. A. Matveev, S. J. Brodsky , D. V. Shirkov….
E. A. Kuraev et al., Phys. Lett. B 712, (2012)
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 33
Panda Simulations
A. Dbeyssi PhD
Suzdal, 4-VI-2014 34
Proton form factors at large q2
E. T-G. and M. P. Rekalo, Phys. Lett. B 504, 291 (2001)
Egle Tomasi-Gustafsson
L = 2 10 32 cm-2 s-1 100 days
Applies to NN and NN Interaction (Pomeranchuk theorem) t=0 : not a QCD regime!
Connection with QCD asymptotics?
Phragmèn-Lindelöf theorem
Analyticity
Panda
Efficiency extrapolation
• Experimental statistical error ~ 1/ V e
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 35
V e e
Hadronic background
Channels with more than two charged particles in the final state can be rejected using the kinematics (missing mass)
5.4 8.2 13.9
>99% >99% >99.9%
>5% >5% >6%
N of fired crystals
in the EMC
>5 >5 >5
[178°-182°] [178°-182°] [175°-185°]
[178°-182°] [178°-182°] [175°-185°]
Invariant mass [GeV] No cut > 2.14 GeV > 2.5 GeV
Background [Events] 0 0 0
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 36
Starting from 107 events:
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 37
Most probable in the mb region : - Five pion production - Charge exchange
A.Dbeyssi amd ETG, Panda-note AD-12-12-13
About cross sections…
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 38
At rest
p=5 GeV/c
p=10 GeV/c
Five pions are preferentially created in annihilation at rest
• Quark-gluon dynamics (similar to quark-gluon plasma)
• Statistical models • Quasi-two-body dorway
states • ……
Role of the different contribution to the NN potential (dynamical selection rules)
Exclusive final states
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 39
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 40
April 2014: FAIR employees planted
10000 trees for forest conversion
Stabilizing the ground
On-line web camera
GSI today
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 41
Conclusions
• FAIR will provide antiproton and ion beams with unprecedented intensity and quality.
• In the final construction FAIR consists of eight ring colliders with up to 1,100 meters in circumference, two linear accelerators and ~3.5 kilometers beam control tubes.
• Timeline • Construction MOU in preparation • Start construction • Preassembly in Juelich in 2016/17 • Mounting at FAIR in 2017/18 • Commissioning end 2018
• Major advances in different fields of physics are expected!
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson
Thank you for attention!
42
благодарю за внимание
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 43
• Almost 600,000 cubic metres of concrete • Over 35,000 tonnes of steel • 500,000 tonnes of other construction material will be used
to build FAIR. • Over one million cubic metres of soil will be excavated
during construction and used at a later stage to cover underground structures.
• Work on the foundations is set to start shortly. This will involve embedding around 1,500 piles, with diameters of 1.2 metres, up to 65 metres into the ground to create a suitable foundation for the buildings.
• During the most intensive construction periods, up to 600 construction workers, technicians and engineers will be working at the site.
More numbers
Egle Tomasi-Gustafsson
Suzdal, 4-VI-2014
44
Crossing Symmetry
Scattering and annihilation
channels:
- Described by the same amplitude :
- function of two kinematical variables, s and t
k2 → – k2
- which scan different kinematical regions
p2 → – p2
GPD,GDA,TDA….(x,x,t)
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014
0p
- eepp
0/ p Jpp
45
ggpp
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014
Open charm
The quark model was expected to describe well the excited states of Ds (cs)
Two new states 0+ and 1+
do not fit the potential predictions
46
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014
More excited states were discovered... quantum numbers were assigned
… by studying DK,D*K distributions 47
Open charm
The detector
Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson 48
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 49
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 50
Models in T.L. Region (polarization)
VDM : IJL
Ext. VDM
‘QCD inspired’
R
Ay Axx Ayy
Axz
Azz
E. T-G., F. Lacroix, C. Duterte, G.I. Gakh, EPJA 24, 419(2005)
X(3872)
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014
New state discovered by Belle in
e+e-Y(4S)BB; BK X X (J/ y p+p-), J/y µ+µ- or e+e-
M = 3872.0 0.6 0.5 MeV
2.3 MeV (90 % C.L.)
X(3872) seen also by CDF
ppX+all; X D0 D*0 (p0),
M = 3871.4 0.7 0.4 MeV
PRL 91, 262001 (2003)
Seen also by
51
Narrow width
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014
X(3872) highlights
X(3872) J/ y p+p- M = 3871.57 0.25 MeV M(D0 D*0 )= 3871.94 0.33 MeV
X 2.3 MeV (90 % C.L.)
Very close to DD* threshold
p+p- invariant mass (Belle 03) X(3872)J/y g- (Belle 05) C-parity =+
p+p- angular distr. (Belle 05) (CDF 06) J
PC = 1+(?)
X0,+ J/ yr0,+ (Babar 05) I=0
Br[X J/ y p+p- p0] Br[X J/ y p+p-] =
1.0±0.4 ±0.3 (Belle 05)
0.8±0.3 (Babar 10)
I=0
I=1
Large Isospin
violation
52
Egle Tomasi-Gustafsson Suzdal, 4-VI-2014 53
Time-Like Electromagnetic Form Factors
Antiparticles, antihadrons, antimatter
Egle Tomasi-Gustafsson
• The relativistic equation for e- has a second solution with the same mass but opposite sign (e+)
(Dirac, 1930) • Discovery of the positron (Anderson, 1933)
(cosmic rays)
• Generalization to the strong interaction, invariance by C-parity (Wick, 1958)
Suzdal, 4-VI-2014
• CPT invariance (Lee, 1957) • Discovery of antiproton,
(Segré, Chamberlain,1955) • Discovery of antineutron
(Cork, 1956) • Discovery of antideuteron
(Zichichi, 1965)
54
d = 150 mm
d = 20 mm
p
by cortesy of D. Rodriguez
Dedicated beam pipe
Backward End Cap Calorimeter and MVD will be not used
Modular structure HPGe encapsulated crystal attached to the X-Cooler
Modular design
55 Suzdal, 4-VI-2014 Egle Tomasi-Gustafsson
Unité mixte de recherche
CNRS-IN2P3
Université Paris-Sud 11
91406 Orsay cedex
Tél. : +33 1 69 15 73 40
Fax : +33 1 69 15 64 70
http://ipnweb.in2p3.fr
PANDA IPNO –R&D Détecteurs Department – septembre 2012
Prototype
120 PbWO4 II crystals operated at
-25°± 0.2°
g (3 MeV-10 GeV) and e detection
• Fully designed at IPN Orsay
• Under construction
• To be tested with cosmics and
photon beam (2012/13)
Barrel Calorimeter
• 11000 PWO type II Crystals
• Large Area Avalanche Photodiodes
(APD) readout, (2) 7x 14 mm2
• σ(E)/E1.%/√E + const (
Egle Tomasi-Gustafsson 57
The Rosenbluth separation
)2(2)2(2
)1(
1Q
MGQ
EG
Mottd
d
d
d
e
2M4
2Q
,
1
2
e2)tan1(21
-
qe
2M
G2E
GR
e
Holds for 1g exchange only
Linearity of the reduced cross section
PRL 94, 142301 (2005)
tan2qe dependence e
Q2 f
ixed
Suzdal, 4-VI-2014
Egle Tomasi-Gustafsson 58
Proton Form Factors ...before
Rosenbluth separation/ Polarization observables
Dipole approximation: GD=(1+Q2/0.71 GeV2)-2
Suzdal, 4-VI-2014
Egle Tomasi-
Gustafsson
S1
S2
S=S1+S2
J=L+S
P=(-1)L+1
C=(-1)L+S
L
Exotic Quantum Numbers with Simple Hybrids
Gluon 1– (TM) 1+(TE)
1S0, 0–+ 1++ 1––
3S1, 1–– 0+- 0–+
1+- 1–+
2+- 2–+
JPC exotic impossible for qq
JPC = 0--,0+-, 1-+, 2+-, 3-+
• hybrids
Production -> All possible quantum numbers Discovery potential!
Suzdal, 4-VI-2014 59