1,211 research outputs found
Production of Black Holes in TeV-Scale Gravity
Copious production of microscopic black holes is one of the least
model-dependent predictions of TeV-scale gravity scenarios. We review the
arguments behind this assertion and discuss opportunities to track the striking
associated signatures in the near future. These include searches at neutrino
telescopes, such as AMANDA and RICE, at cosmic ray air shower facilities, such
as the Pierre Auger Observatory, and at colliders, such as the Large Hadron
Collider.Comment: 8 pages, 10 figures, fortschritte.sty (included); talk presented at
the 35th International Symposium Ahrenshoop on the Theory of Elementary
Particles, Aug. 26-30, 2002, Berlin-Schmoeckwitz, German
Zooming-in on Instantons at HERA
In view of the intriguing, preliminary search results for instanton-induced
events at HERA from the H1 collaboration, some important remaining theoretical
issues are discussed. Notably, the question is addressed, to which extent the
H1 analysis may be directly compared to our original predictions from
instanton-perturbation theory, since certain fiducial cuts are lacking in the
H1 data. Various theoretical uncertainties are evaluated and their impact on
the observed excess is discussed. An improved understanding of the experimental
findings along with an encouraging over-all agreement with our original
predictions seems to emerge.Comment: 13 pages, 12 figure
QCDINS 2.0 - A Monte Carlo generator for instanton-induced processes in deep-inelastic scattering
We describe a Monte Carlo event generator for the simulation of QCD-instanton
induced processes in deep-inelastic scattering (HERA). The QCDINS package is
designed as an ``add-on'' hard process generator interfaced to the general
hadronic event simulation package HERWIG. It incorporates the theoretically
predicted production rate for instanton-induced events as well as the essential
characteristics that have been derived theoretically for the partonic final
state of instanton-induced processes: notably, the flavour democratic and
isotropic production of the partonic final state, energy weight factors
different for gluons and quarks, and a high average multiplicity O(10) of
produced partons with a Poisson distribution of the gluon multiplicity. While
the subsequent perturbative evolution of the generated partons is always
handled by the HERWIG package, the final hadronization step may optionally be
performed also by means of the general hadronic event simulation package
JETSET.Comment: 51 pages, 3 figure
Phenomenology of Multi-W Processes in Cosmic Rays
We report on a study of the potential of various cosmic ray physics
experiments to search for Standard Model processes involving the
nonperturbative production of O(30) weak gauge bosons. Whereas present and
near-future experiments are insensitive to proton-induced processes,
neutrino-induced processes give rise to promising signatures and rates in
AMANDA, DUMAND, MACRO and NESTOR provided that a cosmic neutrino flux exists at
levels suggested by recent models of active galactic nuclei. The Fly's Eye
currently constrains the largest region of parameter space characterizing
multi-W phenomena.Comment: (Invited talk presented by A. Ringwald at 17th Johns Hopkins Workshop
on Current Problems in Particle Theory, Particles and the Universe, July
30-August 1, 1993, Budapest, Hungary), 16 pages (LaTeX) + 10 uuencoded
PostScript figures, CERN-TH.7005/93, UCLA/93/TEP/3
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