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    • 11:00 11:10
      Update on invisible decay study 10m
      Speaker: Satoshi Kawaguchi (Tokyo Institute of Technology (JP))
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      Speaker: Masahiro Tanaka (Tokyo Institute of Technology (JP))
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      Liverpool studies 10m

      Pythia8 versus Pythia-6-Dis-modified
      From Uta KleinAdd contact
      To Lhec-phys-higgs TopAdd contact
      Date 2017-04-12 17:19
      Contact photo
      Message Body
      Dear All,

      I had a quick look at the default Pythia8 installation.
      In particular, I checked the NC DIS process
      define j = g u d s c b u~ d~ s~ c~ b~
      define p = g u d s c b u~ d~ s~ c~ b~
      generate p e- > j e- j

      for some pt>6.5 GeV cuts for all particles species (jets, electrons, photons)

      For technical reasons I was using 2 slightly different MG5 versions,
      but as tested multiple times, this doesn't matter, and I got the same cross section of 1.33*10^4 pb for both versions (so another check)
      I was always using Delphes 3.4 and the FCC-eh detector.

      Here the comparison on Delphes-level

          Pythia8     Pythia6-Dis-modified

      jetsize 2.266 2.448
      eta-jet 3.495 1.165 -> the distributions look totally different,
      and 'ill' for Pythia8 (like 'ears' of a hare, nothing central)
      pt-jet 10.76GeV 11.22GeV
      el-size 4860 5000
      eta-el 1.527 -1.806 -> looks totally wrong for Pythia8
      MET> 7.256GeV 2.539GeV -> about factor 2 higher for Pythia8

      So, although nominal Pythia8 has a survival rate of 4860 out of 5000 events (our Dis modified Pythia has 5000 out of 5000), for me it looks like that something is going wrong and may need a further adjustment for a pe-collider.

      Please let me know your observations. The kinematics for NC-pe DIS can be easily checked. Jets have to be more central/forward (0 to +eta ranges) while electrons are scattered backwards (-eta range) - at least for the small pT-jets that I was using here.

      Any other observations?
      Thanks and cheers, Uta.

      Speaker: Uta Klein (University of Liverpool (GB))

      I will comment of Pythia8 mysteries

    • 11:30 11:40
      H to phiphi to 4b 10m
      Speaker: Mr. Chen Zhang (Peking University)
    • 11:40 11:50
      Status of RPC SUSY 10m
      Speaker: Dr. Kechen Wang (DESY / IHEP)
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      Status of Wits Studies 10m
      Speakers: Mukesh Kumar (University of the Witwatersrand (ZA)) , Xifeng Ruan (University of the Witwatersrand (ZA))
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      FCNC top-Higgs couplings 10m
      Speaker: hao sun (DaLian University of Technology)
    • 12:10 12:20
      Top-q-gamma FCNC 10m
      Speakers: Orhan CAKIR (Ankara University) , Orhan Cakir (University of Ankara) , Prof. Orhan Cakir (Ankara University (TR)) , Orhan Cakir (University of Ankara (TR)) , Orhan Cakir (University of Ankara (TR))
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