21 26 Aug 2005, Rio de Janeiro, Brazil The PANDA project at GSI.

2126 Aug 2005, Rio de Janeiro, Brazil

The PANDA project at GSI

PANDA

antiProton ANnihilationat DArmstadt

PANDAPANDA is an experiment that will use a very high intensity

p beam with momentum from 1.5 GeV/c up to15 GeV/c on a fixed proton target :

√s from 2.25 up to 5.47 GeV

It will continue and extend the successful physics programinitiated at facilities like LEAR at CERN and FERMILAB

Physics topics covered in PANDAPhysics topics covered in PANDA• Charmonium• Exotics : hybrids, glueballs and other exotics• Mesons in nuclear matter• Charmonium absorption in nuclear matter• Hypernuclear physics• Open charm factory : CP violation, and D physics• Crossed-channel Compton scattering and related exclusive processes• Electromagnetic form factors of the proton in the time-like region

The PANDA collaboration

PANDA Collaboration

• At present a group of 340 physicists from 47 institutions of 16 countries

Basel, Beijing, Bochum, Bonn, IFIN Bucharest, Catania, Cracow, Dresden, Edinburg, Erlangen, Ferrara, Frankfurt, Genova, Giessen, Glasgow, KVI Groningen, GSI, Inst. of Physics Helsinki, FZ Jülich,

JINR, Katowice, Lanzhou, LNF, Mainz, Milano, Minsk, TU München, Münster, Northwestern, BINP Novosibirsk, Pavia, Piemonte Orientale,

IPN Orsay, IHEP Protvino, PNPI St. Petersburg, Stockholm, Dep. A. Avogadro Torino, Dep. Fis.

Sperimentale Torino, Torino Politecnico,Trieste, TSL Uppsala, Tübingen, Uppsala, Valencia, SINS Warsaw, TU Warsaw, AAS Wien

Spokesperson: Ulrich Wiedner – Uppsaladeputy Paola Gianotti, INFN-LNF

Austria – Belaruz - China - Finland - France - Germany – Holland - Italy – Poland –Romania-Russia – Spain - Sweden – Switzerland – U.K. – U.S.A..

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The PANDA experimental site at the

Gesellschaft für Schwer Ionenforschung(GSI)

facility in Darmstadt - Germany

High Intensity Mode:Luminosity 2x1032 cm-2s-1 (2x107Hz)p/p (st. cooling) ~10-4

High Resolution Mode:Luminosity 2x1031 cms p/p (electron cooling) ~10-5

For a detailed descriptionof the FAIR facilityproject at GSI see talk by K. Peters onMonday morningplenary session

The PANDA experiment site within FAIR The PANDA experiment site within FAIR

The PANDA detector

The PANDA detectorThe PANDA detector

Detector requirements• full angular acceptance and angular resolution for charged particles and

• particle identification (, K , e, ) in the range up to ~ 8 GeV/c• high momentum resolution in a wide energy range• high rate capabilities, especially in interaction point region and forward detector : expected interaction rate ~ 107


• beam of p of momentum from 1.5 up to 15 GeV/c• proton pellet target (or gas jet target)• Micro Vertex Detector• Inner Time of Flight detector (still under discussion)• Tracking detector : Straw Tubes Tracker or TPC• DIRC• Electromagnetic Calorimeter• 2 Tesla solenoid• scintillation muon counters• 2 stations of Multiwire Drift Chambers

Target region Spectrometer

also wire targets or foil targetsfor nuclear target physics

carbon target interleaved withsilicon detector for hypernuclearphysics


• 6 stations of Multiwire Drift Chambers• analysing dipole : 2 Tesla·meter• Forward DIRC and RICH• Forward Electromagnetic Calorimeters• Time of Flight counters• Hadron Calorimeter

Forward SpectrometerTop View

The pellet targetThe pellet target

• To achieve design luminosity required effective target thickness of 3.8x1015 atoms/cm2

• Frozen droplets of hydrogen (pallets) successfully operating at CELSIUS/WASA facility very close now to requirements (2.8x1015 atoms/cm2), still working to reach goal• pellet beam pipe 6 mm diameter

The microvertex detectorThe microvertex detector

Baseline requirements :1. vertex spatial resolution ~100 m (charm vertices)2. low material thickness to avoid MCS and conversions3. forward angular coverage since PANDA is fixed target4. radiation hardness technology

pellet targetpipe : 6 mm

beam

forward diskbarrel

present design : barrel geometry with 5 layers. First 3 layers: pixel 400x50 m2 ,2 outer layers : double sided strips are forseen to reduce material

5 forward wheels, pixel dimensions : 150x50 m2, 2 outer layers : double sided strips to reduce material

barrel innermost3 layers, pixels50x400 m2

mm

~ 7.2 million pixels in barrel~ 2 million pixel forward disks



Pixel technologyHybrid technology used in LHC, pixel total thickness :

250m (sensor)+200m(frontend)= 450 mdigitization performed locally with time over threshold method (as in Atlas)

Forseen 0.13 m technology for readout chip probably standard of the near future:smaller chips and lower power consumption than 0.25 m technology

Pixel technologyHybrid technology used in LHC, pixel total thickness :

250m (sensor)+200m(frontend)= 450 mdigitization performed locally with time over threshold method (as in Atlas)

Forseen 0.13 m technology for readout chip probably standard of the near future:smaller chips and lower power consumption than 0.25 m technology

Under investigation option 100x100 m2 pixel detectorUnder investigation option 100x100 m2 pixel detector

The PANDA detector : central tracker, straw tube optionThe PANDA detector : central tracker, straw tube option

11 double-layers of 150 cm long straw drift tubes. First and last double-layers parallel to beamaxis, remaining arranget at skew angles from 2° to 3° allowing z position measurement at 1cmprecision. Left-right ambiguity resolution thanks to double and staggered layers.

beam

Straw diameter : from 4mm innermost to 8 mm outermostwire diameter : 20m , wall thickness : 30 m~ 9000 straws

Also charge division for measuringposition along beam axis.

Prototype straws

typical momentum resolution for particles between 2 and 8 GeV/c in relevant physicschannels : 1%

Expected x and y resolution :150 m

Ar-CO2 mixture with gasgain ~ 105 for long operationtime

outer radius42 cm

inner radius15 cm

The PANDA detector : central tracker, TPC optionThe PANDA detector : central tracker, TPC option

Gas Electron Multiplier detectors for charge readout at the end caps : new solutionfrom CERN

inner radius : 15 cmouter radius : 42 cmlength : 150 cmgas volume : 700 liters

typical momentum resolution for particles between 2 and 8 GeV/c in relevant physicschannels : (0.5 – 2 )%

more challenging : collection ofcharge in ungated mode andtracks of different eventsE field along beam axis

The PANDA detector : multiwire drift chambersThe PANDA detector : multiwire drift chambers

Dc1 and Dc2 option under study:cathod foil drift chambers

2 stations inside solenoid to track particles below 22° placed1.4 and 2. m downstram target.Octagonal frames

high flux rates expected near beam pipe : 3x104cmsneeded detector resistent to ageingminimal detector material : X0 ~ 1%

6 stations forward,2 before dipole2 inside dipole, 2 downstream dipole

detector planes arrangedin staggered pairs to resolve

left/right ambiguity

forward MDC inside dipoleor downstream it, is made of3 pairs of detection planes

vertical, +45° , 45°rectangular shape to match

dipole symmetry

forward MDC before dipoleis made of 4 pairs of detection planes

vertical, +45° , 45°, horizontaloctagonal shape to match

solenoid azimuthal symmetry

Coverage of very highforward momentum tracksand low momentum spiralizing

expected resolutionof MDC system for3 GeV/c protons :p/p = 0.2 %

Charged particle identification for angles > 22° : the DircCharged particle identification for angles > 22° : the DircCharged particle ID essential in PANDA . Achieved with DIRC, RICH, dE/dx , ToF

The DIRC for angles > 22°Measure Cerenkov cone calculate angle of emission

of Cerenkov light measure of the particleFused silica with n= 1.47 will allow K identification starting at 460 MeV/c

PMT option : read out by 7000 PMT located outside magnetic field, with ultrapurified water as optical coupling

APD option : read out by APD’s (Geiger mode) just outside the quartz barsR&D in progress for self-quenching Geiger mode APD’s

Alternative option : measure precisely time of arrival of lightinstead of Cerenkov cone reduce PMT’s down to 120

They should be placed in contact with silica bars work in highB field use microchannel PMT’s already available

(25 m microchannel)ACTIVE R&D in progress

quartz bar cross section :17 mm x 30 mm

Charged particle identification for angles < 22° : the forward Dirc and the RichCharged particle identification for angles < 22° : the forward Dirc and the Rich

forward Dirc : fused silica disk (or proximity imaging RICH)angle coverage between 10° and 22°

RICH, located downstream of dipoleangle coverage < 10°

Forward DIRC present design ideas :fused silica (n= 1.47)read out by 2304 pixels 10mm x 5° + 864 pixels 10mm x 10°lower momentum/K separation ~ 1 GeV/cupper momentum /K separation : 10 GeV/c at =0 , 5 GeV/c at = 25°

RICH present design ideas :3rd generation aerogel, hydrophobic, > 80% transmittance and no Hermes ‘meniscus’ difectread out : new type of multipixel hybrid photocatode GaAsP photocatode (60% q.e. in 300-700 nm range) multipixel avalanche diode, 64 pixels 2mm x 2mm, with < 100 ps time resolution in 1.5 T field

Gianluigi Boca, Rio de Janeiro, Brazil, 21-26 Aug 2005

Charged particle identification : dE/dx, ToFCharged particle identification : dE/dx, ToF

A cylindrical Time of Flight scintillation counteris placed around the DIRC

96 strips of fast scintillator like BC404 : decay constant 1.8 nsthickness 0.5 cm

mechanically mounted together with DIRCphototubes : channel plate photomultipliers, can work up to

2.2 Tesla field/K separation at 3 level up to 430 MeV/c at = 90° and

up to 760 MeV/c at = 22°

dE/dx measurements to separate /K/p typically below 800 MeV/cIf TPC will be implemented, it will be ideal device but also Straw Tubes since

working in proportional mode and the MicroVertex Detecor pixels can measure dE/dx

Time of Flight in the Target Region

Gianluigi Boca, Rio de Janeiro, Brazil, 21-26 Aug 2005

the ToF wall in the forward regionthe ToF wall in the forward region

particle identification with momentum < 5 GeV/cdistance ToF wall from target : 7 m; 5.6 m wide, 1.4 m tall60 vertical strips of scintillator 5-10 cm wide

side ToF wallinside dipole5 vertical strips10 cm wide, 1 m long

Simulations show that with thehelp of the tracking system, a timeresolution of 50 ps can be achieved for thisToF system

The PANDA detector : identification system

The PANDA detector : identification system

muon system only for pattern recognitionmomentum measured in MVDCoverage up to 60°Scintillator counters : 96 strips 10 cm wide 200 cm long, 1 cm thickMini Drift Tube counters : stations of double layer of 4 or 6 drift tube planes

scintillatorcounters

MDT

Required fast, high resolution, radiation hard scintillator for between 20 MeV - 4 GeVPresently favored solution : PbWO4 (PWO) crystals 22 cm2 22 X0 read out by APD’sused for the presence of strong magnetic field. Expected resolutions of < 2%/√E + 1%

The PANDA detector : the EM calorimetersThe PANDA detector : the EM calorimeters

EM calorimeter locatedin three positions : central barrel end caps forward

upstream end cap : 0.34 m radius,816 crystals, segmentation in 16 slices

Central Barrel

Barrel : 2.5 m long, 0.54 m radius, 11360 crystals downstream end cap : 1 m radius,6864 crystals

The PANDA detector : the EM calorimetersThe PANDA detector : the EM calorimeters

the end caps

Forward : Shashlyk modules composed of lead absorbers and scintillators

(E)E

(1.960.1)%(2.740.05)%E GeV

The forward hadronic calorimeterThe forward hadronic calorimeter

Detect neutrons, KL and to trigger on forward hadronic showersFilter for muon counters.Located 8 m downstream the targetPlan to refurbish and use the calorimeter MIRAC from WA8020 + 20 modules arranged in 2 rowsEach module contains 100 layers steel-scintillator, 1.12 m long for atotal 4.8 absorption lengths. Including phototubes and light guidesis 170 cm long.Read out with WLS fibers into phototubes

MIRAC calorimeter

PANDA arrangment

beamdirection

Geant 4 simulation showsresolution /E = 0.40/√E

Physics topicsin more detail

Charmonium physicsCharmonium physics1 Charmonium masses and widths below and above the open charm threshold are predicted by non-relativistic potential models + relativistic corrections

2 In a p p experiment like PANDA ALL c c states can be formed and not just (as in e+e experiments)

3 Excellent resolution of mass and width of all states driven by resolution on p beam momentum and not by detector performances

E 8

35

ev./

pb

3500 3520 MeV3510

CB

all e

v./

2 M

eV

100

ECM

1000c1

CBallE835

PDG 2005 :M(c)

MeV MeV

Discovery of c by Belle in Bc(KK)confirmed by BaBar, Cleo

Belle

Charmonium physics below the DD threshold : the c issueCharmonium physics below the DD threshold : the c issue

Disagreement of experiments on themass and with early findings byCrystal Ball. Only marginal consistencywith most theoretical predictions.Width measured only at 50 % precision.New high statistic measurement neededto settle the question

Poor agreement among experiments on the mass and the width of the state.Width measured only at 10 % precisionNew high statistic measurement neededto settle the matter

Charmonium physics below the DD threshold : the c issueCharmonium physics below the DD threshold : the c issue

The radiative decays of the cJThe radiative decays of the cJ

Radiative decays like cJ J/ and cJ are described by a dominatingdipole term and multipoles arising from relativistic treatment of interaction between charmonium

and electromagnetic field.This can be checked measuring the angular distributions of the

c0 c1 and c2 radiative decays

Charmonium physics below the DD threshold : the hc issueCharmonium physics below the DD threshold : the hc issue

pp hc c

E835

M±0.2 MeV/c2

C. Patrignani, BEACH04 presentation

e+e 0hc hcc

hc c chadrons

M(hc)MeV/c2

Cleo

A. Tomaradze, QWG04 presentation

This singlet P resonance is very important in determining the spin dependent componentsof the the qq confinement potential . Two recent results presented at conferences and an early E760 result. Agreement on the mass at the 8.5 % level.New high statistic measurement needed !

E760 : M(hc)±0.19 MeV/c2

In hcJ/0 (1992)

What is the X(3872) ?Charmonium 13D2 or 13D3.D0D0* molecule.Charmonium hybrid (ccg).

PDG 2005M=3871.70.6MeV/c2

2.3MeV(90%C.L.)

Good agreement on Xmass of the 4 experiments

Charmonium physics above the DD threshold : the X discoveryCharmonium physics above the DD threshold : the X discovery

Discovery of X(3872) by Belle (2003)

B K X(3872) (and XJ/

confirmed by CDF(2004),D0(2004), BaBar (2005)

Belle

Charmonium physics above the DD thresholdCharmonium physics above the DD threshold

Structures at 4040, 4160 and 4415 need confirmation

relatively narrow states expected by potential model

Above DD threshold charmonium spectrum poorlyknow with measures of R in large steps

What PANDA can do for charmonium physicsWhat PANDA can do for charmonium physics

• At 21032cm-2s-1 accumulate 8 pb-1/day (assuming 50 % overall efficiency) 104107 (cc) states/day.

• Total integrated luminosity 1.5 fb-1/year (at 21032cm-2s-1, assuming 6 months/year data taking).

• Improvements with respect to Fermilab E760/E835:– Up to ten times higher instantaneous luminosity.– Better beam momentum resolution p/p = 10-5 (GSI)

vs 210-4 (FNAL)– Better detector (higher angular coverage, magnetic

field, ability to detect hadronic decay modes).

Gluonic excitations (hybrids, glueballs) and other exoticsGluonic excitations (hybrids, glueballs) and other exotics

• QCD allows for richer spectrum than quark model because gluons

can became principal components of new hadrons : glueballs and

hybrids. Additional gluons allow to have an exotic Jpc forbidden for

regular hadrons. Their properties are determined by the long

distance features of QCD studying them is fundamental !!

Also hadrons with more than qq or 3 quarks are expected to exist.

• Hybryds : qqg

• Glueballs : states of pure glue Oddballs : states of pure glue with exotic quantum numbers: ( etc.)• Other exotics : tetraquarks, pentaquarks.• Exotic JPC will be a powerful signature for experimental detection. • LQCD calculations improved precision along the years in prediction of masses and widths of these states.

_

Gluonic excitationsGluonic excitations

charmonium hybrids

non-charmonium hybrids

Exoti

c c c

g

4000MeV/c2

Exoti

c lig

ht

qq

g

1 -- 1-+

0 200010-2

1

102

ProductionAll Quantumnumberspossible

RecoilMeson

FormationQuantumnumberslike pp

potential and wavefunctions energy levels

1-g exchange

excited glue

excited glueK. Juge, J. Kuti, C. MorningstarPRL 90 (2003) 161601

overlap with manybroad states

overlap with fewnarrow states

see also K.Juge talk at thisconference, parallel sessionon Thursday

Gluonic excitations : glueballs and oddballsGluonic excitations : glueballs and oddballs

Morningstar,Peardon, PRD60(1999)34509Morningstar,Peardon, PRD56(1997)4043

0+-

2+-

Investigation of glueballs is essential to understand long-distance QCD.LQCD predicts 15 glueball states with mass accessibleto PANDA, some with exotic quantum numbers (oddballs).

Glueballs can mix with normal hadronicresonances in same mass range while oddballs, due toexotic JPC are predicted to be narrower and easier tofind in partial wave analysis

Predicted width ~ 100 MeVGlueball color blindness : can dacay in uu, dd,ss and cc

First oddball 2predicted at 4.3 GeV/c2 very wellin the reach of PANDA in formation or production.

Glueballs decays most favourable to PANDA are or if mass < 3.6 GeV/c2 or to J/ orJ/above 3.6 GeV/c2

PANDA can form and produce glueballs (oddbals) : • ppstatistics 2 orders of magnitude better than Jetset at LEAR• also measure pp KK*

• study of (1475)KKseen by Obelix at LEAR

exotic

Other exotics : tetraquarks, pentaquarksOther exotics : tetraquarks, pentaquarks

Recent hints of pentaquarks qqqqq discoveries have been claimed

The(1540) decaying into pKs or nK+ has been seen by 10 experiments.

The weighted average of the mass is1533.6 ± 1.2 MeV/c2

but unfortunately compatibility of 10 measurements is only

1.6x105

Pentaquark with strange content

decaying into with Mass = 1862±2 MeV/c2

and < 18 MeV/c2

claimed by NA49 in 2004

Pentaquarks with charm content decaying into D* pwith Mass = 3099±3±5MeV/c2 and =12 ±3 MeV/c2

claimed by H in 2004

PANDA can access to pentaquarks and tetraquarks (qqqq) up to ~ 2700 MeV/c2

The p p reaction could be studied near threshold

PANDA can access to pentaquarks and tetraquarks (qqqq) up to ~ 2700 MeV/c2

The p p reaction could be studied near threshold

: substantial shifts predicted. Experimental goal of HADES at GSI

Hadrons in nuclear matterHadrons in nuclear matter

DMesons: theoretical predictions on size of mass splitting depending on the model. Important to measure experimentally

Hayaski, PLB 487 (2000) 96Morath, Lee, Weise, priv. Comm.

D

50 MeV

D

D+

vacuumvacuum nuclear mediumnuclear medium

K100 MeV

K+

K

25 MeV

cc mesons sensitive only to gluoncondensate in nuclei due to heavyc mass predicted only 510 MeVmass reduction for J/ and c but

40 MeV for cJ, 100 MeV for and 140 MeV for (3770)

Mass shifts caused by potentialin nuclear matter

Calculation: A. Sibirtsev et al., Eur. Phys. J A6 (1999) 351

high intensity p beam up to 15 GeV/c opens up the possibility of :• study of nuclear bound states with slow Kor produced inside nuclei• study of mass shifts of charmonium states, produced in nuclei and decaying into leptons or • study of production yield of DD pairs produced below threshold in nuclei. Increase of cross section due to increased phase space• dependence of all above on nucleus size• study of the possible effect of the opening, in nuclei, of the DD decay channel to states normally below threshold like (3770), , c2

c J/ c 0,1,2 (3686) (3770)Expected Mass shift

-5 MeV to

-8 MeV

-7 MeV to

-10 MeV

-40 MeV to

-60 MeV

-100 MeV to

-130 MeV

-120 MeV to

-140 MeV

Observation

through e+e-/+- J/ e+e-/+- e+e-/+-

Predicted rates at L = 1032 cm-2s-1: few 10 … few 100 events/day S.H. Lee, nucl-th/0310080

p_

~ 1 fm

final state =e+e- / +- / / J/

t ~ 10…20 fm/c

10 fm/c (collisional broadening)

Hadrons in nuclear matter, physics reach in PANDAHadrons in nuclear matter, physics reach in PANDA

J/ absorption in nuclear matterJ/ absorption in nuclear matter

p + A J/ + (A-1) ; detect J/ +- (e+e-)

J/ absorption cross section in nuclear matter, scarce experimental data

can be used later by experiments that study J/ suppression

as signal for Quark Gluon Plasma

_

Hypernuclear physicsHypernuclear physics

In hypenuclei one (or more) substitute one (or more) nucleon. A whole newset of states can exist containing an extra degree of freedom : strangeness.

The lighter single strangeness ( hypernuclei ) energy levels are predicted inthe frame of the shell model, where the particle is subject to an effective singleparticle potential. Heavier hypernuclei and hypernuclei are described bymore complicated models.

Experimental situation : ~35 hypernuclei established since 50 years agoOnly 6 hypernuclei

produce at threshold in pp use a secondary target where is captured in a hyperatom and then interacts in nucleus

+ AZ A+1(Z)* A+1

(Z1) + ’s)detected in apparatus

A+1(Z+1) +

detect with high resolution germanium detector in coincidence with tag.A+1

(Z-1) subequently decays via pionic cascade into normal nucleus.

-hypernuclei production and detection in PANDA-hypernuclei production and detection in PANDA

-(dss) p(uud) → (uds) (uds)

-2.6 GeV/c

Tag_

secondary target

p

X ray

excitedhyp.nucl.

ground state

hyp.nucl.

‘s)detected

in apparatus

normalnucleus

hypernucleuspionic decay

detecteddetected

Hypernuclei physics : detector requirementsHypernuclei physics : detector requirements

Solid state detector (diamond or silicon)compact : thickness ~ 3 cmhigh rate capabilityhigh resolutioncapillar (2D) or pixel (3D)

position sensitive Germanium detector (like Vega or Agata)

Current state of the art detection resolution : 2 KeV (KEK E419) Current state of the art p detection resolution : E = 1.29 MeV Finuda Collaboration, PLB622: 3544, 2005

Hypernuclei physics : expected rates in PANDAHypernuclei physics : expected rates in PANDA

using a 12C wire as primary target

at L = 2 x1032 cm-2 sPANDA will produce ~ 7x102 / sec

pp() = 2 b @ 3 GeV/c pA() = A2/3 pp()

joint escape probability : 5x10

(trigger on and 100 < P < 500 MeV/c)

reconstruction efficiency : ~ 50 % stopping and capture probability : ~ 20 %

~ 3x103 captured /day

p conversion probability : 5% ~ 150 -hypernuclei /day

emission probability: 50% Ge photopeak efficiency : 10%

~ 7 golden events/day

K+K+ trigger ~ 700 events /day

PANDA as an open charm factoryPANDA as an open charm factory

Running at full luminosity of 2x107, above the 3.73 GeV open charm threshold orat the (3770), assuming (ppDD) ~ 1 b, with 50 % reconstruction efficiencyin the D golden modes from MC calculations, and 107 s running time in a year,PANDA will detect ~ 109/year DD golden mode pairs per year in a SUPER CLEANalmost backgroundless type of event.

PANDA will be the mecca for all those who want to do the D mesons charm physics.The only forseeable next generation charm factory, with possibly 103 times today’sBaBar charm yields. It will continue the very successful program in charm physicsof experiments like Cleo, Focus, BaBar, Belle.

PANDA as an open charm factoryPANDA as an open charm factory

Possibility of studying a large part of the physics issues concerning charm physics :

direct CP violationT-violation

mixing in the D0D0 systemrare and forbidden decays

D+ l+ semileptonic decay and form factors

Dalitz plotsrelative and ABSOLUTE branching ratios

singly and doubly Cabibbo forbidden decaysmultihadronic decays

new D decays

Crossed-channel Compton scattering and related exclusive processesCrossed-channel Compton scattering and related exclusive processes

Recently shown this reaction can be described in terms of Generalized Parton Distributions

pp

Using a hand bag diagram the process separates into a soft part parametrized by GPDs and a hard part described by a quasi-free qq scattering into

Lately a new approach appliedthe same formalism to

pp e+ e

pp

pp + vector meson ()

The production of a hard di-lepton pair is a hardsubprocess that is assumed to factorize from thelower part that is described by a hadron to transition amplitude

Crossed-channel Compton scattering and related exclusive processesCrossed-channel Compton scattering and related exclusive processes

Expected rates at PANDA at

L = 2x1032 cms and √3.2 GeV

Conservative : 103 events/month

Optimistic : 5x104 events/month

PANDA has a great potential for and e detection

Electromagnetic form factors of the proton in the time-like region Electromagnetic form factors of the proton in the time-like region

Electromagnetic form factors in timelike region can be studied inpp ee

to first order QCD (E,P energy, momentum p in cms) :

data at high Q2 are crucial :check Q2 behaviour

check spaceliketimelike equality for corresponding Q2


Proton timelike f.f.measured by severalexperiments at low Q2

at high Q2 only E760and E835 up to

Q2~15 GeV2

but due to lowstatistics measuredonly |GE| and |GM|under assumption

|GE| = |GM|


possibility of measuring form factorsfrom threshold up to 29 GeV2 !

in PANDA :

much wider angular acceptance and higher statistics

possibility of measuring |GE| and |GM| separately

29 GeV2

Time schedule of the project

• 2005 (Jan 15) Technical Proposal (TP) with milestones.

Evaluation and green light for construction.• 2005 (May) Project starts (mainly civil infrastructure).• 2005-2008 Technical Design Report (TDR) according

to milestones set in TP.• 2006 High-intensity running at SIS18.• 2009 SIS100 tunnel ready for installation.• 2010 SIS100 commissioning followed by Physics.• 2011-2013 Step-by-step commissioning of the full

facility.

Time schedule of the projectTime schedule of the project

21 26 Aug 2005, Rio de Janeiro, Brazil The PANDA project at GSI.

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Transcript of 21 26 Aug 2005, Rio de Janeiro, Brazil The PANDA project at GSI.