<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Rivet will need HepMC 2.03.04 or later in order for the VetoedFinalState projection to work properly (see below) <div> <div>Begin forwarded message:</div> <blockquote type="cite"><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">From: "noreply [Lynn Garren]" <<a href="mailto:noreply-savannah@cern.ch">noreply-savannah@cern.ch</a>></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Date: 5 February 2008 17:08:19 GMT</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">To: Lars Sonnenschein <<a href="mailto:Lars.Sonnenschein@cern.ch">Lars.Sonnenschein@cern.ch</a>>, Lynn Garren <<a href="mailto:garren@fnal.gov">garren@fnal.gov</a>>, James Monk <<a href="mailto:jmonk@hep.ucl.ac.uk">jmonk@hep.ucl.ac.uk</a>>, Andreas Pfeiffer <<a href="mailto:andreas.pfeiffer@cern.ch">andreas.pfeiffer@cern.ch</a>>, Pere Mato <<a href="mailto:pere.mato@cern.ch">pere.mato@cern.ch</a>></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Subject: [bug #33077] Outgoing Z boson not stored in hard process vertex</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "> </div> </div> This is an automated notification sent by LCG Savannah. It relates to: bugs #33077, project HepMC - a C++ Event Record for Monte Carlo Generators ============================================================================== LATEST MODIFICATIONS of bugs #33077: ============================================================================== Update of bug #33077 (project hepmc):                  Status:                    None => Fixed                               Open/Closed:                    Open => Closed                     _______________________________________________________ Follow-up Comment #3: The fix for this has been made available by Atlas.  It is in cvs now and will be available in the forthcoming releases 2.01.10 and 2.03.04. ============================================================================== OVERVIEW of bugs #33077: ============================================================================== URL:  <<a href="http://savannah.cern.ch/bugs/?33077">http://savannah.cern.ch/bugs/?33077</a>>                 Summary: Outgoing Z boson not stored in hard process vertex                 Project: HepMC - a C++ Event Record for Monte Carlo Generators            Submitted by: None            Submitted on: 2008-01-29 15:32                Category: None                Severity: 3 - Normal                Priority: 5 - Normal              Item Group: None                  Status: Fixed                 Privacy: Public             Assigned to: sonne        Originator Email: <a href="mailto:jmonk@hep.ucl.ac.uk">jmonk@hep.ucl.ac.uk</a>             Open/Closed: Closed         Discussion Lock: Any    _______________________________________________________ Hi, I've been trying to remove (from a Rivet projection) the decay products of the Z boson in some fortran Herwig Drell-Yan events.  The obvious way to do this is to look through the ancestors of the lepton's production vertex for a Z.  When I tried this I noticed there weren't very many events with final state leptons connected to a Z (or gamma), so I compared the hepevt common from Herwig with the HepMC record.  I found that the HepMC record is missing the Z that is present in the hepevt common: (hepevt): ***** HEPEVT Common Event#: 1, 235 particles (max 10000) ***** Double Precision 4-byte integers, 8-byte floating point numbers, 10000-allocated entries. Indx Stat Par- chil-       (  P_x,       P_y,       P_z,    Energy,       M )      ID  ents dren    Prod (   X,         Y,         Z,        cT)      [mm] ________________________________________________________________________________   1 +101    0    0    (        0,         0,       300,       300,     0.938)    +2212    0    0    (        0,         0,         0,         0)   2 +102    0    0    (        0,         0,      -300,       300,     0.938)    -2212    0    0    (        0,         0,         0,         0)   3 +103    1    0    (        0,         0,         0,       600,       600)       +0    2    0    (        0,         0,         0,         0)   4 +121    6    9    (        0,         0,      46.5,      46.5,      0.32)       +2    6    9    (        0,         0,         0,         0)   5 +122    6   14    (        0,         0,     -45.2,      45.2,      0.32)       -2    6   14    (        0,         0,         0,         0)   6 +120    4    7    (    -5.18,     -2.02,      1.28,      91.9,      91.7)      +23    5    8    (        0,         0,         0,         0)      ^^^^ (HepMC) GenParticle: 1 ID:2212 (P,E)=0,0,300,300.001 Stat:101 PV:0 EV:-2 Pol:(-0,0) F:0 GenParticle: 2 ID:-2212 (P,E)=0,0,-300,300.001 Stat:102 PV:0 EV:-3 Pol:(-0,0) F:0 GenParticle: 3 ID:2 (P,E)=0,0,46.4977,46.4988 Stat:121 PV:-2 EV:-1 Pol:(-0,0) F:0 GenParticle: 4 ID:-2 (P,E)=0,0,-45.2188,45.2199 Stat:122 PV:-3 EV:-1 Pol:(-0,0) F:0 GenParticle: 5 ID:14 (P,E)=6.63997,-1.33916,45.9957,46.4918 Stat:123 PV:-1 EV:-4 Pol:(-0,0) F:0 GenParticle: 6 ID:-14 (P,E)=-6.63997,1.33916,-44.7168,45.2269 Stat:124 PV:-1 EV:-5 Pol:(-0,0) F:0 GenParticle: 7 ID:2 (P,E)=-2.94741,-0.764536,48.0059,47.5284 Stat:141 PV:-1 EV:-6 Pol:(-0,0) F:0 GenParticle: 8 ID:21 (P,E)=2.07153,0.266261,6.91286,7.26033 Stat:2 PV:-6 EV:-7 Pol:(-0,0) F:0 GenParticle: 9 ID:21 (P,E)=0.875875,0.498275,5.94509,6.07635 Stat:2 PV:-6 EV:-8 Pol:(-0,0) F:0 .... GenParticle: 231 ID:22 (P,E)=-0.125745,-0.17355,-13.4178,13.4195 Stat:1 PV:-119 EV:0 Pol:(-0,0) F:0 So there is no pdg_id 23 particle in the HepMC record and it contains four fewer particles than the hepevt record. Comparing to ATLAS' implementation of IO_HERWIG (<a href="http://atlas-sw.cern.ch/cgi-bin/viewcvs-atlas.cgi/offline/Simulation/HepMC/src/IO_HERWIG.cxx?view=markup">http://atlas-sw.cern.ch/cgi-bin/viewcvs-atlas.cgi/offline/Simulation/HepMC/src/IO_HERWIG.cxx?view=markup</a>) I see that ATLAS have added a section of code especially to retain the boson at the hard vertex (line 148-169): //BPK-> index_hard retained if it is a boson    int index_hard = 0;    for ( int i = 1; i <=HEPEVT_Wrapper::number_entries(); i++ ) {      if ( HEPEVT_Wrapper::status(i)==120 ) index_hard=i;      if ( index_hard!=0 ) break;    }        if ( index_hard!=0) {      hard_vtx->add_particle_out( hepevt_particle[index_hard] );      GenVertex* hard_vtx2 = new GenVertex();      hard_vtx2->add_particle_in( hepevt_particle[index_hard] );  for ( int i = 1; i <= HEPEVT_Wrapper::number_entries(); ++i ) { if (  HEPEVT_Wrapper::first_parent(i)==index_hard ) {  hard_vtx2->add_particle_out( hepevt_particle[i] ); }      }      evt->set_signal_process_vertex( hard_vtx );      evt->set_signal_process_vertex( hard_vtx2 );    }    else {      evt->set_signal_process_vertex( hard_vtx );    } Is it intentional that HepMC removes the Z boson from the event record (if so, why?) or is this a bug in the official HepMC that ATLAS have fixed in their private implementation? thanks, James    _______________________________________________________ Follow-up Comments: ------------------------------------------------------- Date: 2008-02-05 17:08              By: Lynn Garren <garren> The fix for this has been made available by Atlas.  It is in cvs now and will be available in the forthcoming releases 2.01.10 and 2.03.04. ------------------------------------------------------- Date: 2008-01-29 16:59              By: Anonymous I saw this behaviour both with the current 2.03.03 version and the previous 2.02.01 that I had been using. James ------------------------------------------------------- Date: 2008-01-29 16:54              By: Lynn Garren <garren> Which version of HepMC?    _______________________________________________________ Carbon-Copy List: CC Address                          | Comment ------------------------------------+----------------------------- 466                                 | -COM- <a href="mailto:jmonk@hep.ucl.ac.uk">jmonk@hep.ucl.ac.uk</a>                 | -SUB- ============================================================================== This item URL is:  <<a href="http://savannah.cern.ch/bugs/?33077">http://savannah.cern.ch/bugs/?33077</a>> _______________________________________________  Message sent via/by LCG Savannah  <a href="http://savannah.cern.ch/">http://savannah.cern.ch/</a> </blockquote></div> </body></html>