simulation studies of the panda detector at gsi

DPG 2003 Tübingen C. Schwarz

Simulation studies of the PANDA detector at GSI

Carsten Schwarz for the Antiproton Physics Study Group

PANDA = Proton ANtiproton at DArmstadt

IntroductionHESR (High Energy Storage Ring)Physics program

Simulation of Detector componentsMicro Vertex TrackerStraw Tube TrackerDIRCRICHCalorimeter

Summary & Outlook


HESR@Future GSI

High Energy Storage Ring

Momenta 1.5-15 GeV/c Spread 10-4

10-5 (<8 GeV/c) Beam Ø 100 um p stored in ring 5 x 1010

L (pellet target) 2 x 1032 cm-2 s-1

Int. L 10 pb-1/day

HESR


Physics Program

Charmoniumspectroscopy

Medium modificationsof D mesons and J/Ψ in nuclei

HypernucleiCP violation

GlueballsHybrids


Simulation framework: C++ Geant4 Root

Event Generation

DPM pbar+p background

UrQMD pbar+A

PndEvtGen (Pluto)

PndSimApp

GEANT4 modelling of the detector

PndRecoApp

Tracking, EMC-cluster finding, RICH rings...

PandaApp

'user analysis', PID, spectra

Full simulation

Fast simulation


Angular AcceptanceFormation of ψ’ and decay in muons

ψ’ µ+ µ-

µ+µ-

ψ’ J/ψ + X

similarly electrons:-->for large angles calorimeter needed.


PANDA Detector

Target spectrometer Forward spectrometer


Micro Vertex Detector (MVD)

7.2 mio. barrel pixels50 x 300 µm

2 mio. forward pixels100 x 150 µm

beam pipe

pelle

t pip

e

Readout: ASICs (ATLAS/CMS) 0.37% X0

or pixel one side - readout other side (TESLA)

Layers 5 barrel, 5 endcapthickness 200 µmthick. 5 layers 1-3.5 % X0

resolution σφz ≈ 25 ... 100 µm


MVD geometry

x

y

zD0

Z0


Geant4 and multiple scattering

�

0

� 13.6 MeV

�

pcz

xX0

1

�

0.038lnxX0


MVD

DIRC

STT

Straw tubes

Number of double layersSkew angle of double layers 1 and 15 Skew angle of double layers 2-14

150o

2o-3o

Straw tube wall thicknessWire thicknessGasLengthDiameter of tubes in double layers 1-5, 6-10, and 11-15Number of straw tubes

26 µm20 µm90%He+10%C4H10 150 cm4, 6, 8 mm8734

Transverse resolution σx,y

Longitudinal resolution σz

150 µm 1 mm

Event example:pp --> φφ --> 4K


DIRC

less space than aerogelscosts of calorimeterno problems with field

Detecting Internally Reflected -light

PID: tracking --> p, RICH --> β --> m


DIRC

K eff.

π miss-id.

reaction pp � � � φφ at √s = 3.6 GeV/c2

degree

degree

degr

ee

degr

ee

χ2/n=2.4pion beta=0.974547 photons


DIRC Time Of Propagation

∆T ,

T2

T1 (discussed at Belle)

⇒reduced # of PMT for Kaon PID ⇒very good time resolution required (~ 100 ps)


DIRC radiator qualityEdge losses

Edge thickn.

Sharpness of edges should be ≈ 50 µm


Forward RICH Search for good combination radiator ↔ photon detector ↕ magnetic field

4 10 cm

Aerogel (n=1.02) ↔ visible light PD HPD

C6F14 (n=1.24) ↔ CsI coated photo cath.

(λ < 210 nm = UV)

Proximity "focussing"compact detector


Aerogel and Rayleigh scatteringP

hoto

n # generated

Rayleigh scattered

Detected

Det. Eff.

Wavelength [nm]

Combination of aerogel radiator and CsI-photo cathode is not working.

Visible light???

Wavelength [nm]

Aerogel C6F14


Forward RICH

Aerogel n=1.02

Multi pad gasDetector

Mismatch photons<->CsI photon conversion

LHCb

proximity focusing ��

mirrors


Calorimeter

PbWO4

Length = 17 X0

APD readout (in field)σ(E) = 1.54% / E½ + 0.3% (PM)

pp → J/ψ + η γγ


Summary & Outlook

Status

Design of PANDA for GSI Future Project

Simulations in a framework of C++, Geant4, and ROOT

Target spectrometer nearly implemented

Future tasks

Completion of detector implementation (forward spectrometer)

Intensive background simulations

Annihilations ~ 100 mb Reactions nb need 108 events for each valid event to prove background supression --> fast simulation


Antiproton Physics Study Group

T. Barnes1, D. Bettoni2, R. Calabrese2, W. Cassing3, M. Düren3, P.Thörngren Engblom4, S. Ganzhur5, A. Gillitzer6, O. Hartmann7, V. Hejny6, P. Kienle8, H. Koch5, W. Kühn3, Agnes Lundborg9, Elin Lundström9, U. Lynen7, R. Meier10, V. Metag3, P. Moskal6, Örjan Nordhage9, H. Orth7, S. Paul8, K. Peters5, J. Pochodzalla11, J. Ritman3, Y. Rogov12, H. Rohdjess13, M. Sapozhnikov12, L. Schmitt8, C. Schwarz7, K. Seth14, A. Sokolov7, V. Uzhinsky12, N. Vlassov12, W. Weise8, U. Wiedner9

1) University of Tennessee, Knoxville2) INFN, Ferrara3) Universität Gießen4) Uppsala University5) Experimentalphysik 1, Bochum6) Institut für Kernphysik, FZ Jülich7) GSI Darmstadt8) Technische Universität München9) ISV, Uppsala10) Physikalisches Institut, Tübingen11) Institut für Kernphysik, Mainz12) JINR, Dubna13)Universität Bonn14) Northwestern University, Evanston

simulation studies of the panda detector at gsi

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