Sep. 17, 2003 KTB

• The future GSI facility

• Physics with antiprotons at the GSI future facility

• The PANDA detector

• Target options and vertex detector, triggers

• Summary and outlook

PANDA at the GSI Future Facility

Kai-Thomas Brinkmann

Sep. 17, 2003

VERTEX 2003

Low Wood, Lake Windermere

supported by BMBF

Sep. 17, 2003 KTB

Press Release 16/2003, http://www.bmbf.de

05.02.2003

Bulmahn gives green light for large-scale research equipment "We are securing an international top position for German basic research"

...Basic research in the natural sciences has a long tradition in Germany. Its success is inseparably linked with the use of large-scale equipment at national and international research centres. "With the new concept, basic research in Germany will start from an excellent position when entering a new decade of successful work", Minister Bulmahn said.

Together with European partners, the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt shall extend its equipment in a phased approach and become a leading European physics centre. At least 25% of the costs amounting to €675 million are to be supplied by foreign partners.

Sep. 17, 2003 KTB

Intensity upgrade of the existing accelerator complex

1012/s, 1.5 A GeV 238U28+

Acceleration in SIS 100

2(4)·1013/s 30 GeV protons

1010/s 238U73+ to 25 (- 35) A GeV

Storage in SIS 200

Technical prerequisitesBeam cooling

Fast-ramping superconducting magnets

Primary BeamsPrimary Beams

SIS 100/200

SIS 18

http://www-new.gsi.de/zukunftsprojekt/index_e.html

Sep. 17, 2003 KTB

Secondary beams

Radioactive beams from 1.5 to 2 A GeV, 104 more intensive than at present

Antiprotons from 3 (0) to 30 GeV

Storage rings, beam coolingRadioactive beams

e – A collider

1011 stored and cooled antiprotons of 0.8 to 14.5 GeV/c

Secondary BeamsSecondary Beams

HESRNESR

CR SuperFRS

Sep. 17, 2003 KTB

Extraction into HESR for experiments

1011 stored antiprotons0.8 to 14.5 GeVx/x ≥ 100 µm

Secondary Beams – AntiprotonsSecondary Beams – Antiprotons

L = 2·1032 cm-2s-1 p/p ≥ 10-4

L = 1·1031 cm-2s-1 p/p ≥ 10-5

Sep. 17, 2003 KTB

antiPProton ANANnihilation experiment located at the new

accelerator facility at DADArmstadt ..in short: PANDAPANDA• Many open questions in non-perturbative QCD

- Charmonium spectroscopy - Hybrids - New states

• Chiral symmetry in SU(3) and SU(4)

- Hadrons in nuclear matter

• Hypernuclei: “3rd dimension of the chart of nuclides“

CP violation in the charm sector, virtual Compton scattering, baryon spectroscopy, antiproton physics at low energies ...

Sep. 17, 2003 KTB

Charmonium spectroscopy

Superior resolution in formation formation

Structure of Hadrons: Quark-Gluon DynamicsStructure of Hadrons: Quark-Gluon Dynamics

BallCrystalee

100 keV

pp

Sep. 17, 2003 KTB

HybridsQuarks in mesons are well-localized objects connected

by gluons which can be excited (qqg, gg states)

Structure of Hadrons: Quark-Gluon DynamicsStructure of Hadrons: Quark-Gluon Dynamics

Expectation: Hybrid states better separated from fewer states in charm region

Sep. 17, 2003 KTB

Hadrons in nuclear matter and chiral restoration

Mesons in coldcold baryonic matter: production with antiprotons

p - beams

SIS 18

SIS 200T [MeV]

300

LHC

RHIC

SPS

Mesons in Nuclear MatterMesons in Nuclear Matter

Sep. 17, 2003 KTB

Mesons in Nuclear MatterMesons in Nuclear Matter

SIS: increased K- yield in nuclei through medium modification

Interpretation: effective mass in the medium differs from the free mass

FOPI, KaoS, ANKE

pionic atoms

GSI CBM and PANDA

Sep. 17, 2003 KTB

Hadrons in nuclei D effective mass opens strong decay channels

→ properties of (vector) mesons changed

Mesons in Nuclear MatterMesons in Nuclear Matter

Sep. 17, 2003 KTB

DetectorsDetectors

C. Schwarz, GSI

Fixed-target experiment

Forward-backward asymmetry required

Solenoid + dipole

Granularity increase with decreasing scattering angle

Lower quality requirements for backward hemisphere

Access to most detectors will be possible through the upstream end of the detector (e.g. DIRC) only.

verte

x

detector

1m

Sep. 17, 2003 KTB

DetectorsDetectors

PANDA, top view

PANDA, side view

Sep. 17, 2003 KTB

Pellet target: 1016 atoms/cm2 , pellets of 20-40 µm diameter

1 mm

L = 1031 cm-2s-1 with 5·1010 p in HESR, suited for high resolution mode, p/p ~ 10-5, with e--cooling (up to 8 GeV)

TargetsTargets

Sep. 17, 2003 KTB

Cluster jet target: Up to 1015 atoms/cm2

about 1 cm long in interaction region

Superfluid Helium targets: 1015 atoms/cm2, droplets, 0.5-100 µm ø with little divergence only (<0.1°)

Heavy ion targets: heavy gases, wires, and foils

L=2·1032/cm2s with 2·1011 p in HESR

(p/p ~ 10-4 with stochastic cooling)

A. Khoukaz, U Münster

TargetsTargets

Sep. 17, 2003 KTB

• Panda will have to cope with an extended interaction region

• Primary vertex often unknown

• Wires and (perhaps) pellets define z with ~20 µm accuracy, displacement observable

• 107 interactions per second have to be handled and efficiently searched for events of desired shape

Targets and TriggerTargets and Trigger

Sep. 17, 2003 KTB

Detectors: Forward SpectrometerDetectors: Forward Spectrometer

C. Schwarz, GSI

Forward dipole:• Max. B-field 2 Tm, actual field given by beam energy

• 1 m gap

• Tracking with drift chambers

• PID with Cherenkov

• e-m calorimeter

• Hadronic calorimeter

• Muon chambers

Sep. 17, 2003 KTB

Detectors: e-m Calorimeter BarrelDetectors: e-m Calorimeter Barrel

material PbWO4

size of crystals 3.5 X 3.5 X 15 cm3

thickness 17 X0

energy resolution 1.54% / (E/GeV) + 0.3%

time resolution < 150 ps

no of crystals 7150

angular coverage 96% of 4π

APD readout,

fast scintillator to

handle high rate

Sep. 17, 2003 KTB

Detectors: DIRCDetectors: DIRC

PID (e, , , K, p):below 50 hadronic calorimeter

50<Θ<220 aerogel Cherenkov counter

or forward RICH

220<Θ<1400 DIRC (BABAR@SLAC)

Simulated DIRC response:

/ K sep.

Sep. 17, 2003 KTB

DIRC provides particle ID above 700 MeV/c only,

but dynamic range of particles extends down to much lower momenta, esp. in backward direction

Time-of-flight and/or energy loss measurement required!

Add plastic barrel, use Silicon detector pulse height …

DetectorsDetectors

Sep. 17, 2003 KTB

Detectors: Outer TrackerDetectors: Outer Tracker

Straw tubes Alternating tilted layers • 15 double layers• 9000 tubes• Layers 2-14 are inclined with skew angles between 4-9o

• Tube length –1.5 m• Tube diameters – 4, 6, 8 mm• 20 µm aluminized mylar, anode wire 20 µm thick

• Light materials

• Self-supporting structure

• High rate capability due to single-straw readout

Sep. 17, 2003 KTB

Detectors: Outer TrackerDetectors: Outer Tracker

pp

Performance studies (GEANT4)

KTB Feb. 04, 2003

Transverse resolution 150 µm

Longitudinal resolution 1 mm

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

Micro-vertex detectorConceptual design adopts state-of-the-art silicon sensor techniques (ATLAS/CMS/ALICE inner tracker layers)

A. Sokolov, GSI

Design features:• 5 layers forward of 90°

• Barrel and forward disk structures• Smallest possible inner radius• Fast readout

Sep. 17, 2003 KTB

7.2M barrel pixels, 50 μm x 300 μm

2M forward pixels, 100 μm x 150 μm

5 layers, 200 μm thick sensors (0.25%X0)

Bump-bonded readout, 300 µm thick (0.37% X0)

Detectors: Inner VertexDetectors: Inner Vertex

forward wheels

pixels 100 µm X 150 µm

beam pipe

pelle

t pip

e

barrel

pixels 50 µm X 300 µm

ToF

total area < 0.2 m2

Sep. 17, 2003 KTB

Radial deviation Longitudinal dev.

tracky

x

z

µm51D µm82Z

p)GeV5.8(p

KTB April 24, 2003

Detectors: Inner VertexDetectors: Inner Vertex

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

Micro-vertex detector optimisation

Minimum distance to vertex “point”

Beam pipe diameter needed for accelerator reasons, exhaust rate of targets, radiation load

Number of track points

Detector thickness (scattering, conversion)

Pixel size Extrapolation of present-day technology;

estimation of potential of technologies which are currently under development

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

Micro-vertex detector optimisation

distance / mm

Change in beam pipe diameter2 cm 4 cm(may be neededfor vacuum and pumping)

p)GeV2Pc(p

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

Barrel 90 staves, forward 120 staves

Thickness: staves 0.32% X0

cooling 0.4% X0

TOTAL 0.96% to 3.6% X0

Beam pipe now BeAl alloy, 500 µm

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

Present round of

simulations

(A. Sokolov, GSI)

Conversion probabilities (from pp 30 at 8 GeV/c)

Beam pipe 0.9%

Vertex detector 3.1%

Straw tracker 3.5% (2% from support)

DIRC 20%

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

/ deg / deg

/ m

m

/ m

m

Spatial

resolution

Layer (or disk) number

Detector Resolution [m]

Multiple scattering for different polar angles [m]

Z(R) 90o 30o 9o

1 12 (40) 70 (25) 0 0 8

2 12 (40) 70 (25) 5 14 35

3 12 (40) 70 (25) 13 38 120

4 70 (40) 12 (25) 26 68 180

5 70 (40) 12 (25) 45 132 250

Multiple scattering of µ with Pc = 1 GeV

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

Modification of pixel orientation (size 50 µm x 400 µm)

1st and 3rd – 5th layers with pads to beam

2nd layer || to beam direction

Pad intrinsic resolution 12 µm x 70 µm

Mean resolution for pp4 events at 8 GeV

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

(3770) D+D- K++K-+2++2-

D [mm] Z [mm]

Only longitudinal coordinate sensitive to D-mesons

Sep. 17, 2003 KTB

8 GeV/c

Detectors: Inner VertexDetectors: Inner Vertex

Sep. 17, 2003 KTB

other theof Capture

one ofDetection

pp

HypernucleiHypernuclei

Sep. 17, 2003 KTB

Detectors: Inner VertexDetectors: Inner Vertex

Considerations on radiation hardness

Multiplicity of neutrons/protons, p+Fe, 7 GeV/c, about 10 (total particle multiplicity 30)

[UrQMD, Galoyan&Polanski hep-ph/0304196]

Neutron flux: HI targets aiming at 107 interactions/s, Mn = 10

=> Φn 106 cm-2s-1 in innermost layer (r = 1 cm)

3·1013 neutrons per year, probably less in case of Hydrogen targets

Sep. 17, 2003 KTB

DAQ and TriggerDAQ and Trigger

• Self-triggered detector readout• Flash ADCs • Synchronization via distributed clock, 50 ps resolution• NO trigger signals, but FPGA-based flexible data reduction, feature extraction and filtering on the fly• High-performance computer nodes and high-bandwidth connections, Gbit Ethernet• Hardware: PC memories and FPGAs

Self-Triggered Data Push Architecture to allow parallel selection of different event types

Sep. 17, 2003 KTB

SummarySummary

PANDA @ GSI will have a rich physics programme.

A broad range of physics topics will be covered with one multi-purpose detector setup.

For most of these topics, a micro-vertex detector is essential.

Studies for the detector layout are under way.Also under investigation: alternative designs, e.g. employing MAPS and/or strip detectors.

Sep. 17, 2003 KTB

U BochumU BonnU & INFN BresciaU CataniaU CracowGSI Darmstadt TU DresdenJINR Dubna I + IIU ErlangenNWU EvanstonU & INFN FerraraU FrankfurtLNF-INFN FrascatiU & INFN GenovaU GlasgowU Gießen

KVI Groningen IKP Jülich I + IIU KatowiceLANL Los AlamosU MainzTU MünchenU MünsterBINP NovosibirskU PaviaU of SilesiaU TorinoPolitechnico di TorinoU & INFN TriesteU TübingenU & TSL UppsalaÖAdW ViennaSINS Warsaw

40 Institutes (32 Locations) from 9 Countries:Austria - Germany – Italy – Netherlands – Poland

– Russia – Sweden – United Kingdom – USA