37 research outputs found
Closing the Low-mass Axigluon Window
In this report, I will present the current status of the low-mass axigluon.
The axigluon is a massive, color octet, axial vector boson, predicted in, e.g.,
chiral color models and some technicolor models, with a mass of order the
electroweak scale. Axigluons with a mass larger than about 125 GeV to nearly 1
TeV can be eliminated by di-jet production at hadron colliders like the
TEVATRON, but a low-mass window exists that the di-jet search can not probe.
Upsilon decays can rule out axigluons with a mass up to 25 GeV, and low energy
e^+ e^- (PEP and PETRA) can rule out axigluons with a mass up to 50 GeV using a
measurement of R. Top production at the TEVATRON disfavors a light axigluon. A
measurement of R at LEP strongly disfavors a light axigluon, and rules out an
axigluon with mass < 365 GeV.Comment: 8 pages, LaTeX, 4 .eps figures, uses aipproc.sty and psfi
Leptoquark Production and Identification at High Energy Lepton Colliders
Leptoquarks can be produced in substantial numbers for masses very close to
the collider centre of mass energy in , , and
collisions due to the quark content of the photon resulting in equivalently
high discovery limits. Using polarization asymmetries in an collider
the ten different types of leptoquarks listed by Buchm\"uller, R\"uckl and
Wyler can be distinquished from one another for leptoquark masses essentially
up to the kinematic limit. Thus, if a leptoquark were discovered, an
collider could play a crucial role in determining its origins.Comment: LaTex file uses aipproc.sty, epsfig, and rotating. 9 pages with 8
postscript figures. Talk given at 20th Annual MRST
(Montreal-Rochester-Syracuse-Toronto) Meeting on High-Energy Physics: MRST
98: Toward the Theory of Everything, Montreal, Canada, 13-15 May 199
What Can We Learn About Leptoquarks At LEP200?
We investigate the discovery potential for first generation leptoquarks at
the LEP200 collider. We consider direct leptoquark searches using
single leptoquark production via resolved photon contributions which offers a
much higher kinematic limit than the more commonly considered leptoquark pair
production process. Depending on the coupling strength of the leptoquark,
search limits can be obtained to within a few GeV of . We also
consider LQ limits that can be obtained from t-channel interferences effects in
.Comment: Latex file uses revtex version 3, epsfig, and rotate, 5 postscript
figures are attache
Recoil Corrections of Order to the Hydrogen Energy Levels Revisited
The recoil correction of order to the hydrogen energy
levels is recalculated and a discrepancy existing in the literature on this
correction for the 1S energy level, is resolved. An analytic expression for the
correction to the S-levels with arbitrary principal quantum number is obtained.Comment: 17 pages, ReVTe
Fragmentation production of doubly heavy baryons
Baryons with a single heavy quark are being studied experimentally at
present. Baryons with two units of heavy flavor will be abundantly produced not
only at future colliders, but also at existing facilities. In this paper we
study the production via heavy quark fragmentation of baryons containing two
heavy quarks at the Tevatron, the LHC, HERA, and the NLC. The production rate
is woefully small at HERA and at the NLC, but significant at and
machines. We present distributions in various kinematical variables
in addition to the integrated cross sections at hadron colliders.Comment: 13 pages, macro package epsfig needed, 6 .eps figure files in a
separate uuencoded, compressed and tarred file; complete paper available at
http://www.physics.carleton.ca/~mad/papers/paper.p
Photon-Photon and Electron-Photon Colliders with Energies Below a TeV
We investigate the potential for detecting and studying Higgs bosons in and collisions at future linear colliders with energies below a TeV. Our study incorporates realistic spectra based on available laser technology, and NLC and CLIC acceleration techniques. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson based on a devoted low energy machine with GeV; b) the heavy MSSM Higgs bosons; and c) charged Higgs bosons in collisions.We investigate the potential for detecting and studying Higgs bosons in and collisions at future linear colliders with energies below a TeV. Our study incorporates realistic spectra based on available laser technology, and NLC and CLIC acceleration techniques. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson based on a devoted low energy machine with GeV; b) the heavy MSSM Higgs bosons; and c) charged Higgs bosons in collisions