Download presentation
Presentation is loading. Please wait.
Published byValentine Powell Modified over 6 years ago
1
Extra Energy in Inelastic Hadronic Interactions in GHEISHA / GEANT4
David Bailey University of Toronto Intend to look hadronic interactions in FCAL, … But first checked basic characteristics of hadronic interactions in MC ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
2
Extra Energy in GHEISHA - David Bailey
Basic Parameters GEANT ref 2 PhysicsList copied from example N02 GEANT 3.21 Particles generated at centre of huge uniform cubes side half-length = 105 km material either Liquid Hydrogen or Iron “Total Energy” is the sum of step energy losses neutrino energies ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
3
Extra Energy in GHEISHA - David Bailey
100 GeV/c2 + in Iron ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
4
Total Energy for 100 GeV/c2 + in hydrogen
ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
5
Total Energy for 1 GeV/c2 neutrons in hydrogen
ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
6
Sample GEANT4 1 GeV/c2 proton in Hydrogen event printout
ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
7
Kinetic Energies of some GEANT4 interactions
proton 985 MeV 0 MeV proton (438 MeV) pi0 (456 MeV) neutron (248 MeV) pi+ (503 MeV) ∆Q=936MeV neutron 543 MeV proton 0 MeV proton (389 MeV) pi0 (297 MeV) neutron (543 MeV) ∆Q=821MeV ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
8
Extra Energy in GHEISHA - David Bailey
Gheisha Fortran Gheisha seems to calculate the target particle mass by counting the number of outgoing baryons. SUBROUTINE TWOCLU(IPPP,NFL,AVERN) / SUBROUTINE GENXPT(IPPP,NFL,AVERN) C *** GENERATION OF X- AND PT- VALUES FOR ALL PRODUCED PARTICLES *** C *** NVE 01-AUG-1988 CERN GENEVA *** … C** LORENTZ TRANSFORMATION IN LAB SYSTEM C** 27 TARG=0. DO 36 I=1,NT IF(PV(5,I).GT.0.5) TARG=TARG+1. CALL LOR(I,MX2,I) 36 CONTINUE C*DCB --> David Bailey modification to prevent counting C*DCB incoming baryon as a target particle if (amas.gt.0.5) targ=targ-1. ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
9
1 GeV/c2 neutron in hydrogen, Total Energy
ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
10
Total Energy of 100 GeV/c2 pi+ in Iron
ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
11
Extra Energy in GHEISHA - David Bailey
GEANT 4 has similar code same place as fix to previous energy non-conservation bug // $Id: G4HEInelastic.cc,v /07/09 09:48:35 hpw Exp $ … // Lorentz transformation in lab system targ = 0; for( i=0; i < vecLen; i++ ) { if( pv[i].getType() == baryonType )targ++; if(verboseLevel > 1) pv[i].Print(i); pv[i].Lor( pv[i], pvmx[1] ); } if ( targ <1) targ = 1; (Twice) but my first attempt (yesterday) to “fix” it failed, and I noticed something else … ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
12
Total Energy for 1 GeV/c2 antineutrons in hydrogen
ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
13
Extra Energy in GHEISHA - David Bailey
Summary GHEISHA inelastic hadronic interactions have some “peculiarities”. These are old enough that they must be considered GEANT3 “features”. GEANT4 accurately reproduces these “features”. Do we want these “features” in GEANT4? ATLAS GEANT4 - 6 November 2000 Extra Energy in GHEISHA - David Bailey
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.