8,284 research outputs found
Looking for the Top-squark at the Tevatron with four jets
The scalar partner of the top quark is relatively light in many models of
supersymmetry breaking. We study the production of top squarks (stops) at the
Tevatron collider and their subsequent decay through baryon-number violating
couplings such that the final state contains no leptons. Performing a
detector-level analysis, we demonstrate that, even in the absence of leptons or
missing energy, stop masses upto 210 \gev/c^2 can be accessible at the
Tevatron.Comment: 4 pages, 4 embedded figures, RevTe
Domain walls in Born-Infeld-dilaton background
We study the dynamics of domain walls in Einstein-Born-Infeld-dilaton theory.
Dilaton is non-trivially coupled with the Born-Infeld electromagnetic field. We
find three different types of solutions consistent with the dynamic domain
walls. For every case, the solutions have singularity. Further more, in these
backgrounds, we study the dynamics of domain walls. We qualitatively plot
various form of the bulk metrics and the potential encountered by the domain
walls. In many cases, depending upon the value of the parameters, the domain
walls show bouncing universe and also undergo inflationary phase followed by
standard decelerated expansion.Comment: 18 pages,6 figures,latex, References added, Some points clarifie
Observable signals in a string inspired axion-dilaton background and Randall-Sundrum scenario
Rotation angle of the plane of polarization of the distant galactic radio
waves has been estimated in a string inspired axion-dilaton background. It is
found that the axion,dual to the field strength of the second rank
antisymmetric massless Kalb-Ramond field in the string spectrum, produces a
wavelength independent optical rotation which is much larger than that produced
by the dilaton. Detection of such rotation has been reported in some recent
cosmological experiments. The observed value has been compared with our
estimated theoretical value following various cosmological constraints. The
effects of warped extra dimensions in a braneworld scenario on such an optical
rotation have been investigated.Comment: 17 Pages, Latex, article revised, To appear in Physical Review
Electronic spectra of linear HCH and cumulene carbene HC
The transition of linear HCH
(A) has been observed in a neon matrix and gas phase. The assignment is based
on mass-selective experiments, extrapolation of previous results of the longer
HCH homologues, and density functional and multi-state CASPT2
theoretical methods. Another band system starting at 303 nm in neon is assigned
as the transition of the cumulene carbene
pentatetraenylidene HC (B).Comment: 7 pages, 4 figures, 5 table
Semirings embedded in a completely regular semiring
summary:Recently, we have shown that a semiring is completely regular if and only if is a union of skew-rings. In this paper we show that a semiring satisfying can be embedded in a completely regular semiring if and only if is additive separative
The interplay between the charged Higgs and squark-gluino events at the LHC
In some extensions of the standard model with extended Higgs sectors, events
from new particle production may pass the selection criteria for Higgs search
in different channels at the LHC - 14 TeV and mimic Higgs signals. This
intriguing possibility is illustrated by PYTHIA based simulations using several
representative points in the parameter space of the minimal supersymmetric
standard model (MSSM) including a point in the minimal supergravity model
consistent with the Dark matter (DM) relic density data. Our simulations
explore the interplay between the charged Higgs signal and typical
squark-gluino events. We argue that the standard selections like the one based
on the polarization properties of the 's from charged Higgs decay, though
adequate for handling the SM background, may not be very efficient in the
presence of SUSY backgrounds. We then propose an alternative search strategy
based on pure kinematics which sufficiently controls both the SM and the MSSM
backgrounds. For charged Higgs masses () in the deep decoupling regime
(600 GeV \lsim m_{H^{\pm}} \lsim 800 GeV) this method works well and extends
the LHC reach close to 800 GeV for an integrated luminosity of 30
with or without the SUSY background. For a lighter charged Higgs a judicious
combination of the old selections and some of the cuts proposed by us may
disentangle the Higgs signal from the squark-gluino backgrounds quite
effectively
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