48 research outputs found
Search for Production via Trilepton Final States in collisions at TeV
We have searched for associated production of the lightest chargino,
, and next-to-lightest neutralino, , of the
Minimal Supersymmetric Standard Model in collisions at
\mbox{ = 1.8 TeV} using the \D0 detector at the Fermilab Tevatron
collider. Data corresponding to an integrated luminosity of 12.5 \ipb
were examined for events containing three isolated leptons. No evidence for
pair production was found. Limits on
BrBr are
presented.Comment: 17 pages (13 + 1 page table + 3 pages figures). 3 PostScript figures
will follow in a UUEncoded, gzip'd, tar file. Text in LaTex format. Submitted
to Physical Review Letters. Replace comments - Had to resumbmit version with
EPSF directive
Measurement of the Boson Mass
A measurement of the mass of the boson is presented based on a sample of
5982 decays observed in collisions at
= 1.8~TeV with the D\O\ detector during the 1992--1993 run. From a
fit to the transverse mass spectrum, combined with measurements of the
boson mass, the boson mass is measured to be .Comment: 12 pages, LaTex, style Revtex, including 3 postscript figures
(submitted to PRL
Second Generation Leptoquark Search in p\bar{p} Collisions at = 1.8 TeV
We report on a search for second generation leptoquarks with the D\O\
detector at the Fermilab Tevatron collider at = 1.8 TeV.
This search is based on 12.7 pb of data. Second generation leptoquarks
are assumed to be produced in pairs and to decay into a muon and quark with
branching ratio or to neutrino and quark with branching ratio
. We obtain cross section times branching ratio limits as a function
of leptoquark mass and set a lower limit on the leptoquark mass of 111
GeV/c for and 89 GeV/c for at the 95%\
confidence level.Comment: 18 pages, FERMILAB-PUB-95/185-
The Azimuthal Decorrelation of Jets Widely Separated in Rapidity
This study reports the first measurement of the azimuthal decorrelation
between jets with pseudorapidity separation up to five units. The data were
accumulated using the D{\O}detector during the 1992--1993 collider run of the
Fermilab Tevatron at 1.8 TeV. These results are compared to
next--to--leading order (NLO) QCD predictions and to two leading--log
approximations (LLA) where the leading--log terms are resummed to all orders in
. The final state jets as predicted by NLO QCD
show less azimuthal decorrelation than the data. The parton showering LLA Monte
Carlo {\small HERWIG} describes the data well; an analytical LLA prediction
based on BFKL resummation shows more decorrelation than the data.Comment: 6 pages with 4 figures, all uuencoded and gzippe
Jet Production via Strongly-Interacting Color-Singlet Exchange in Collisions
A study of the particle multiplicity between jets with large rapidity
separation has been performed using the D{\O}detector at the Fermilab Tevatron
Collider operating at TeV. A significant excess of
low-multiplicity events is observed above the expectation for color-exchange
processes. The measured fractional excess is , which is consistent with a strongly-interacting
color-singlet (colorless) exchange process and cannot be explained by
electroweak exchange alone. A lower limit of 0.80% (95% C.L.) is obtained on
the fraction of dijet events with color-singlet exchange, independent of the
rapidity gap survival probability.Comment: 15 pages (REVTeX), 3 PS figs (uuencoded/tar compressed, epsf.sty)
Complete postscript available at http://d0sgi0.fnal.gov/d0pubs/journals.html
Submitted to Physical Review Letter
The Anti-Apoptotic Activity of BAG3 Is Restricted by Caspases and the Proteasome
Caspase-mediated cleavage and proteasomal degradation of ubiquitinated proteins are two independent mechanisms for the regulation of protein stability and cellular function. We previously reported BAG3 overexpression protected ubiquitinated clients, such as AKT, from proteasomal degradation and conferred cytoprotection against heat shock. We hypothesized that the BAG3 protein is regulated by proteolysis. caspase-resistant mutant. Caspase and proteasome inhibition resulted in partial and independent protection of BAG3 whereas inhibitors of both blocked BAG3 degradation. STS-induced apoptosis was increased when BAG3 was silenced, and retention of BAG3 was associated with cytoprotection.BAG3 is tightly controlled by selective degradation during STS exposure. Loss of BAG3 under STS injury required sequential caspase cleavage followed by polyubiquitination and proteasomal degradation. The need for dual regulation of BAG3 in apoptosis suggests a key role for BAG3 in cancer cell resistance to apoptosis
The Isolated Photon Cross Section in the Central and Forward Rapidity Regions in p-pbar Collisions at sqrt(s) = 1.8 TeV
A measurement of the cross section for production of single, isolated photons
is reported for transverse energies in the range of 10-125 GeV, for two regions
of pseudorapidity, |\eta|<0.9 and 1.6<|\eta|<2.5. The data represent 12.9 pb-1
of integrated luminosity accumulated in p-pbar collisions at sqrt{s} = 1.8 TeV
and recorded with the D0 detector at the Fermilab Tevatron Collider.Comment: 9 pages, submitted to Physical Review Letters,
http://d0sgi0.fnal.gov/~womersle/photon_prl_preprint.p
Measurement of the gauge boson couplings in Collisions at TeV
The gauge boson couplings were measured using () events at TeV observed with the
{D\O} detector at the Fermilab Tevatron Collider. The signal, obtained from the
data corresponding to an integrated luminosity of , agrees
well with the Standard Model prediction. A fit to the photon transverse energy
spectrum yields limits at the 95% confidence level on the CP--conserving
anomalous coupling parameters of ( = 0) and
( = 0).Comment: 16pages (14pages + 2figure pages) Uses ReVTEX Two postscript files
for figures will follow immediatel
Search for Right-Handed Bosons and Heavy in Collisions at 1.8 TeV
We report on a search for right-handed bosons (). We used data
collected with the D{\O} detector at the Fermilab Tevatron collider
at 1.8 TeV to search for decays into an electron and a massive
right-handed neutrino . Using the inclusive electron
data, we set mass limits independent of the decay:
GeV/c and GeV/c at the 95% confidence level, valid for
and respectively. The latter also
represents a new lower limit on the mass of a heavy left-handed boson
() decaying into . In addition, limits on valid for
larger values of the mass are obtained assuming that decays to an
electron and two jets.Comment: 15 pages, 5 figures (in UUencoded postscript file which will follow)
uses preprint,epsf,eqsecnum,aps,floats,revtex Submitted to Physical Review
Letter