(hep-ph/9707355)
published in Mod.Phys.Lett.A12:3143-3152,1997
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A short summary of this Startup Meeting .....
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1) Leptoquarks
==============
Interactions with theorists (thanks to M.Spira) allowed already
to benefit from NLO calculations for LQ.
This is important for HERA since NLO corrections can enhance
the production cross-section of a LQ by an important factor
(e.g. ~30% for a 200 GeV LQ coupling to e+ + d).
See M. Spira et al. paper for more details.
2) Projects
===========
Two main tasks/projects have been defined during the startup meeting.
a) R-parity violating SUSY
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We do not have any event generator to deal with cascade
decays of squarks (e.g. decays into charginos are missing
and can be of high importance).
=> Project = write a (user friendly) tool for Rp Susy
generation in ep collisions (something like SUSYGEN
which exists for e+e-, or ISASUSY for pp/ppbar)
We should be able not to start from scratch, but use
stuff from available packages (SUSYGEN,SPYTHIA,GRACE..)
We hope to agree on a common strategy by next (June) meeting.
It would be fine to have a first version of this complete tool
by the end of the year.
b) W Production at HERA
=======================
a "hot" topic for ZEUS and H1 !
Both H1 and ZEUS use EPVEC generator for W production.
Recent calculation of this process using COMPHEP package
showed some disagreements with EPVEC (regions of phase
space absent in EPVEC)
=> Project = compare deeply into details W production
calculation by EPVEC, COMPHEP and GRACE, understand
the differences.
Consider higher order corrections.
Many people are interested by working on this/these topics.
3) Organisation
===============
o It has been decided that minutes were not necessary.
Copies of transparencies are available on request at
DESY library.
o Next meeting : scheduled on Wednesday 10 June, 1 pm,
at DESY (the room will be specified later)
Contributions are welcome !
o Reminder : mid-term meeting will take place at DESY,
most likely from 5 to 9 October
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