J.RItman PANDA Collab. Meeting, May 2003 Status of the PANDA Simulations Event Generator UrQMD p A MVD Resolution Time of Flight Estimates of Data Rates

J.RItmanPANDA Collab. Meeting, May 2003

Status of the PANDA Simulations

Event Generator UrQMD p A MVD Resolution Time of Flight Estimates of Data Rates “Complete” Analysis of pp(3770)DD Updated “to-do” list


Using UrQMD for pA (A.Galoyan)

UrQMD ~OK but must be modified Galoyan&Polanski hep-ph/0304196

Multiplicity distribution Produced Particlesp (7 GeV/c) + Fe (10K events)

Multiplicity Mass [GeV/c2]

p,n


Phase Space Distribution

All particles vs P Neutron dN/d


MVD Resolution (A.Sokolov)

Investigate MVD resolution with pp4(8GeV) Take small angle scattering into account with a

reduced weight for hits in outer layers Modify pad orientation:

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

2nd layer || to beam direction Pad intrinsic resolution 12x70 m Increase diameter of the the beam pipe


Vertex Resolution

D0 = radial distance Z0 = longitudinal distance

polar angle polar angle polar angle


Increased Beam Pipe Diameter


Z0 Resolution, R=40 mm Beam Pipe

Z0 increasesfrom ~13 m to ~18 m


Systematic Error in Z0


Momentum Resolution

mean resolution for pp4 events at 8 GeV


Time of Flight (C.Schwarz)

Kaon ID in the DIRC starts at about 600 MeV/c Can Reduce # of DIRC PMTs with ToF Redundancy Fast trigger Resolution ~ 100 ps

Detector type: RPC or scintillator?

TOP (Time of Propagation)

DIRC vs ToF

DIRC is needed for P>600 MeV/c and ToF for P<600 MeV/c


Estimated Data Rates (P.Salabura+JR)

Number of Readout Channels Mean Multiplicity Data per Event Event rate (107 Hz interactions)


Number of Readout Channels

MVD 9.2x106 pixels STT 8.7x103 wires MDCT 1.7x103 wires DIRC 1.0x104 PMTs EMCT 7.5x103 crystals RICH 4.5x104 pads MuonT 3.2x104 cells +ToF+FS …


Mean Multiplicities (pp 8 GeV/c)

MVD 12 hits/evt x 2.5 pads/hit = 30 STT 94 MDCT 37 DIRC 7 bars/evt x 20 PMTs/hit x ½ 70 EMCT 82 RICH 1 hit/evt x 15 pads/hit 15 MuonT 0.26 +ToF+FS ???


Number of bits per Hit (rounded)

MVD Layer(4)+Coordinate(2x10)+sysID(8) = 32 STT Layer(4)+Wire(10)+Time(2x10)+sysID(8)= 48 MDCTLayer(4)+Wire(8)+Time(10)+sysID(8) = 32 DIRC PMT(14)+E(12)+T(12)+sysID(8) = 48 EMCT Crystal(13)+E(15)+sysID(8) = 48 RICH PadNumber(2x8)+sysID(8) = 24 MuonT Cell(12)+T(12)+ sysID(8) =

32 +ToF+FS …


Total Data Rates (107 Hz)

Detector bits/hit Multiplicity Total (GBytes/sec)

MVD 32 30 1.2 STT 48 94 5.6 MDCT 32 37 1.5 DIRC 48 70 4.2 EMCT 48 82 5 RICH 24 15 0.5 MuonT 32 0.25 0.01 +ToF+FS … ?7?

25 GB/s


Analysis of pp(3770)DD (JR)

Single D±K±± Selector (BR=9.1%) pp(3770)DD Background Estimates

report at GSI Docuserver:

http://www-new.gsi.de/onTEAM/tree/temp/1053448016/191053014637.ps


Vertex Resolution (1 D per event)

Force the decay at V=(0.1,0.1,0.4) mm PD=3.3GeV/c

Combine + - - or -++ tracks (i.e. no PID) for reconstruction

M=1865 M=7.3 MeV/c2 ~ 0.71

Z=22 m

VR [mm] VZ [mm]


(3770) DD K+K-2++2-

M+-- [GeV]

10,000 Events


Decay Vertex Location

Transverse Longitudinal

D [mm] Z [mm]

Only longitudinal coordinate sensitive to D-mesons !


Proper Lifetime Determination

N(x) ~ exp{ - |V| M / (P c) }

|V|M/P

c = 292 ± 3 m

input 317 m


DD Kinematical Variables

Missing Mass Squared Invariant Mass

(Mmiss)2 [GeV2] Minv [GeV]

N.B. (M)2 ~ 0.02 GeV2 ~ 31% (no PID)


Fake D-Candidates from Background

Vertex Z - Location + - - Inv. Mass

Vz [mm] Minv [GeV/c2]

80,000 Events


Background Suppression Factors

80,000 input background events 6.6 GeV/c

3,144 D-Candidates (no PID!)

196 events with Vz > 0.1 mm

100 events with 2/dof < 10 (vertex fit)

0 events with a D+ & D- candidate

estimate of remaining cuts by widening cuts above

1/16000 for the second D candidate

1/50 |(Mmiss)2| < 0.002 GeV2

1/10 Minv ~ s


Peak to Background Ratio

Assume a (3770) formation cross section of 160 nb

58

101

501

160001

80000100

31.0091.0

45

160

background

signal

2

2

mb

nb

BRbackground

signal

background

signal

L=1032 140 Counts/hour

(still without PID!!!)


Summary

Event Generator UrQMD p A MVD Resolution Time of Flight Estimates of Data Rates “Complete” Analysis of pp(3770)DD

Outlook (Feb 2003 Meeting)

• pbar-A background generator• Generation of 107 pbar-p background events• Introduction of the absolute time, (in progress) to allow studies of pileup• Add more dead areas/materials• Detailed studies of thresholds, etc.• Layer of ToF between DIRC and EMC• CsI at backward angles?• Can e+e- be selected/triggered (conversion in MVD…)• Improvement of the FastSim• Evaluation of signal/background ratio• Input for Trigger/DAQ• Hypernucleus experiments…

StatusMay 2003


Outlook 2

Target (start detector?) Tof FS 3D Fieldmap Tracking (Kalman) Kinematic fitters Trigger simulations Physics Analysis for specific channels

(e.g. Glueballs, DD, leptons,, *)

group meeting Wed. 11-13

Documents

J.RItman PANDA Collab. Meeting, May 2003 Status of the PANDA Simulations Event Generator UrQMD p A MVD Resolution Time of Flight Estimates of Data Rates