Wrong MC data in file, generated with runMC.C
Wrong pseudorapidity for certain particles which has MC points in TPC.
There are particles with MC points in TPC
and with motherId == -1 (i.e. primary particles)
which have |pseudorapidity| > 3
Pseudorapidity is denoted by eta.
I manually calculated maximum eta for our TPC geometry,
eta = -ln(tan(theta/2))
if max Z = 163.879
and the minimum radius = 40.7
then it turned out that always |eta of primary particle| < 2.1
How to reproduce:
get test.f14.gz file.
It was generated by UrQMD with the following inputfile:
pro 197 79
tar 197 79
nev 1000
imp -20.
ecm 7
tim 200 200
rsd 1979
f13
#f14
f15
f16
f19
f20
xxx
Then checkout mpdroot version (last for 06 october 2023)
$ git checkout a8816513ca8e3f8715d158e682a5bf3b29c1b4b7
fix Z target to 0:
git diff whole repository
$ git diff
diff --git a/macros/common/runMC.C b/macros/common/runMC.C
index 7ff473e3..c0a6384b 100644
--- a/macros/common/runMC.C
+++ b/macros/common/runMC.C
@@ -100,7 +100,7 @@ void runMC(EGenerators generator = EGenerators::BOX, EVMCType vmc = EVMCType::GE
// smearing of beam interaction point
primGen->SetBeam(0.0, 0.0, 0.1, 0.1); // for fix-target set all to 0.0
- primGen->SetTarget(0.0, 24.0); // for fix-target set (-115.0, 0.0)
+ primGen->SetTarget(0.0, 0.0); // for fix-target set (-115.0, 0.0)
primGen->SmearGausVertexZ(kTRUE); // for fix-target set kFALSE
primGen->SmearVertexXY(kTRUE); // for fix-target set kFALSE
build & install mpdroot
run runMC.C
$ root -q -b 'runMC.C(EGenerators::URQMD,EVMCType::GEANT3,0,"test.f14","evetest.root",0,1000,kFALSE,0)'
it will generate evetest.root
For this evetest.root calculate pseudorapidity with macro printEta.C (attached to the issue)
$ root -q 'printEta.C("evetest.root")'
------------------------------------------------------------------
| Welcome to ROOT 6.26/10 https://root.cern |
| (c) 1995-2021, The ROOT Team; conception: R. Brun, F. Rademakers |
| Built for linuxx8664gcc on Aug 17 2023, 08:42:00 |
| From tags/v6-26-10@v6-26-10 |
| With c++ (GCC) 10.2.0 |
| Try '.help', '.demo', '.license', '.credits', '.quit'/'.q' |
------------------------------------------------------------------
Processing printEta.C("evetest.root")...
event 105; trackId: 421; nMCPoints: 13; eta: 3.47782
event 120; trackId: 692; nMCPoints: 21; eta: -3.61608
event 198; trackId: 338; nMCPoints: 25; eta: 3.31506
event 431; trackId: 851; nMCPoints: 17; eta: 3.31008
event 444; trackId: 644; nMCPoints: 86; eta: 3.01901
event 480; trackId: 449; nMCPoints: 3; eta: -3.16936
event 604; trackId: 577; nMCPoints: 30; eta: -3.24977
event 651; trackId: 821; nMCPoints: 49; eta: 3.25251
event 744; trackId: 778; nMCPoints: 50; eta: 3.06697
event 759; trackId: 1099; nMCPoints: 2; eta: -3.05895
event 875; trackId: 1059; nMCPoints: 59; eta: 3.01935
event 975; trackId: 599; nMCPoints: 94; eta: 3.10228
event 975; trackId: 705; nMCPoints: 88; eta: 3.45026