32 research outputs found
Resonant Bound State Production at e- e- Colliders
Observation of a sequence of resonances at an e-e- collider would suggest
bound states of strongly coupled constituents carrying lepton number. Obvious
candidates for these exotic constituents are leptoquarks and leptogluons. We
show that under reasonable assumptions, the existence of one leptogluon flavor
of appropriate mass can give rise to sizeable ``leptoglueball'' production
rates and observable resonance peaks. In contrast, one needs two leptoquark
flavors in order to produce the analogous ``leptoquarkonium'' states. Moreover,
cross-generational leptoquark couplings are necessary to give observable event
rates in many cases, and leptoquarkonium mass splittings are too small to
resolve with realistic beam energy resolutions.Comment: 8 pages, 1 table, plain TeX, requires harvmac. Brief comparison to
leptoglueball production at e+e- colliders added. Other minor changes. To
appear in Physics Letters
Lepto-mesons, Leptoquarkonium and the QCD Potential
We consider bound states of heavy leptoquark-antiquark pairs (lepto-mesons)
as well as leptoquark-antileptoquark pairs (leptoquarkonium). Unlike the
situation for top quarks, leptoquarks (if they exist) may live long enough for
these hadrons to form. We study the spectra and decay widths of these states in
the context of a nonrelativistic potential model which matches the recently
calculated two-loop QCD potential at short distances to a successful
phenomenological quarkonium potential at intermediate distances. We also
compute the expected number of events for these states at future colliders.Comment: 12 pages, 1 figure, 3 tables, plain TeX, requires harvmac. References
updated and minor clarifications made. To appear in Physics Letters
A Comparison of the Use of Binary Decision Trees and Neural Networks in Top Quark Detection
The use of neural networks for signal vs.~background discrimination in
high-energy physics experiment has been investigated and has compared favorably
with the efficiency of traditional kinematic cuts. Recent work in top quark
identification produced a neural network that, for a given top quark mass,
yielded a higher signal to background ratio in Monte Carlo simulation than a
corresponding set of conventional cuts. In this article we discuss another
pattern-recognition algorithm, the binary decision tree. We have applied a
binary decision tree to top quark identification at the Tevatron and found it
to be comparable in performance to the neural network. Furthermore,
reservations about the "black box" nature of neural network discriminators do
not apply to binary decision trees; a binary decision tree may be reduced to a
set of kinematic cuts subject to conventional error analysis.Comment: 14pp. Plain TeX + mtexsis.tex (latter available through 'get
mtexsis.tex'.) Two postscript files avail. by emai