Higgs mass in the Particle class from HepMC

[Sylvie Braibant]

Dear Delphes authors,

I am creating a Delphes root file reading a HepMC file attached below. It is a file containing a H -> ZZ _ 4 muons. The Higgs mass is 125 GeV.
When I check the Higgs mass in the Delphes GenParticle, it is found to be 80 (see a simple output here below) ! The Z mass and muons masses are correct. Can you help me ?

Particle 0 25 Status 22 Mass 80 M1 0 M2 1 D1 8 D2 8
Particle 1 25 Status 44 Mass 80 M1 3 M2 -1 D1 70 D2 70
Particle 2 25 Status 44 Mass 80 M1 8 M2 -1 D1 437 D2 437
Particle 3 25 Status 62 Mass 80 M1 70 M2 -1 D1 567 D2 568
Particle 4 23 Status 22 Mass 91.187 M1 437 M2 -1 D1 569 D2 570
Particle 5 23 Status 22 Mass 91.187 M1 437 M2 -1 D1 574 D2 575
Particle 6 13 Status 23 Mass 0.105658 M1 567 M2 -1 D1 573 D2 573
Particle 7 -13 Status 23 Mass 0.105658 M1 567 M2 -1 D1 571 D2 572
Particle 8 -13 Status 1 Mass 0.105658 M1 570 M2 -1 D1 -1 D2 -1
Particle 9 13 Status 1 Mass 0.105658 M1 569 M2 -1 D1 -1 D2 -1
Particle 10 13 Status 23 Mass 0.105658 M1 568 M2 -1 D1 578 D2 578
Particle 11 -13 Status 23 Mass 0.105658 M1 568 M2 -1 D1 576 D2 577
Particle 12 -13 Status 51 Mass 0.105658 M1 575 M2 -1 D1 579 D2 580
Particle 13 13 Status 52 Mass 0.105658 M1 574 M2 -1 D1 581 D2 581
Particle 14 -13 Status 1 Mass 0.105658 M1 576 M2 -1 D1 -1 D2 -1
Particle 15 13 Status 1 Mass 0.105658 M1 578 M2 -1 D1 -1 D2 -1

[Sylvie Braibant]

HepMC File

[Sylvie Braibant]

Just added the hepMC file.

[Sylvie Braibant]

Just to let you know that I also noticed that the Z mass is always set to the same value 91.187.
But in my case the masses must be read from the hep mc file because the Z might be virtual.

P 1623 23 1.6077243908697550e+01 -1.3144099292684137e+01 -4.6268937077963727e+01 5.5160602834717295e+01 2.1694064830021201e+01 22 0 0 -1259 0
P 1624 23 1.1360516483254251e+01 -2.9653404447860647e+00 -3.5120328291328129e+01 9.7357092487708542e+01 9.0039499219230422e+01 22 0 0 -1260 0
V -1259 0 0 0 0 0 0 2 0
P 1625 13 2.9971726710116289e+00 -1.2967942563467082e+01 -1.0129203049925483e+01 1.6726102259984536e+01 1.0566000000000000e-01 1 0 0 0 0
P 1626 -13 1.3080071237685926e+01 -1.7615672921705666e-01 -3.6139734028038255e+01 3.8434500574732752e+01 1.0566000000000000e-01 1 0 0 0 0
V -1260 0 0 0 0 0 0 2 0
P 1627 13 1.4278096498231942e+01 3.5949326069991912e+01 -4.2687663376930267e+01 5.7606126871341864e+01 1.0566000000000000e-01 1 0 0 0 0
P 1628 -13 -2.9175800149776894e+00 -3.8914666514777970e+01 7.5673350856021342e+00 3.9750965616366663e+01 1.0566000000000000e-01 1 0 0 0 0

[Pavel Demin]

To read mass from the HepMC file you can replace line 340

  candidate->Mass = pdgParticle ? pdgParticle->Mass() : -999.9;

with

  candidate->Mass = fMass;

in classes/DelphesHepMCReader.cc

[Pavel Demin]

I've modified all the readers to use the mass from the event record.

Here is a preliminary version:

​​http://cp3.irmp.ucl.ac.be/downloads/Delphes-3.0.10.pre8.tar.gz

Could you, please check if this version works better?

[Pavel Demin]

New readers that read masses from the MC event files are available in the new release 3.0.10.