1,140 research outputs found
Signature of Charged to Neutral Higgs Boson Decay at the LHC in SUSY Models
We study the signature of decay into at the LHC in SUSY
models. It has only marginal viability in the MSSM. But in the singlet
extensions like the NMSSM one can have a spectacular signature for
decay into over a significant domain of parameter space.Comment: LaTeX file, 11 pages plus two PostScript figure
The Hadronic Tau Decay Signature of a Heavy Charged Higgs Boson at LHC
The hadronic tau decay channel offers by far the best signature for heavy
charged Higgs boson search at the LHC in the large region. By
exploiting the distinct polarization of the tau and its large transverse mass,
along with the accompanying missing--, one can probe for a charged Higgs
boson up to a mass of about 600 GeV in an essentially background-free
environment. The transverse mass distribution of the tau jet also provides a
fairly unambiguous estimate of the charged Higgs boson mass.Comment: 11 pages, latex, including 3 figure
Detecting heavy charged Higgs bosons at the LHC with triple b-tagging
We investigate the charged Higgs boson signal at the LHC using its dominant
production and decay modes with triple b-tagging, i.e. , followed by leptonic decay of one W and hadronic decay of
the other. We consider the continuum background from the associated production
of with a b- or a light quark or gluon jet, which can be mis-tagged
as b-jet. We reconstruct the top quark masses to identify the 3rd b-jet
accompanying the pair, and use its p_T distribution to distinguish
the signal from the background. Combining this with the reconstruction of the
mass gives a viable signature over two interesting regions of the
parameter space - i.e. and .Comment: 10 pages, latex, 4 figure
Using Tau Polarization for Charged Higgs Boson and SUSY Searches at LHC
The polarization can be easily measured at LHC in the 1-prong hadronic
decay channel by measuring what fraction of the -jet momentum is
carried by the charged track. A simple cut requiring this fraction to be >0.8
retains most of the polarization of +1 -jet signal while
suppressing the polarization of -1 -jet background and practically
eliminating the fake background. This can be utilized to extract the
charged Higgs signal. It can be also utilized to extract the SUSY signal in the
stau NLSP region, and in particular the stau co-annihilaton region.Comment: 8 pages, 9 figures; Fig.8 and Fig.9 are replaced, published in
"Physics at the Large Hadron Collider", A Platinum Jubilee Special Issue of
the Indian National Science Academy, Springer (2009) p 20
A Minimal See-Saw Model for Hierarchical Neutrino Masses with Large Mixing
The atmospheric and solar neutrino oscillation data suggest hierarchical
neutrino masses with at least one large mixing. The simplest see-saw models for
reconciling the two features are U(1) extensions of the SM with flavour
dependent gauge charges. I discuss a minimal model of this type containing two
heavy right-handed neutrinos, which have normal Dirac couplings to
and but suppressed ones to . It can naturally account for the
large (small) mixing solutions to the atmospheric (solar) neutrino oscillation
data.Comment: 6 pages, Latex, Invited Talk at the 6th San Miniato Topical Seminar
on `Neutrino and Astroparticle Physics', to appear in Nuclear Physics B
(Proc. Suppl.
Physics Prospects at the Hadron Colliders
I start with a brief introduction to the elementary particles and their
interactions, Higgs mechanism and supersymmetry. The major physics objectives
of the Tevatron and LHC colliders are identified. The status and prospects of
the top quark, charged Higgs boson and superparticle searches are discussed in
detail, while those of the neutral Higgs boson(s) are covered in a parallel
talk by R.J.N. Phillips at this workshop.Comment: 16 pages Latex + 15 figures (available on request
SUSY Contributions to and Top Decay
I report on a systematic analysis of the MSSM parameter space to obtain the
best SUSY solution to the anomaly within the constraint of top quark
decay. Phenomenological implications for top decay and direct stop production
at the Tevatron collider are discussed.Comment: Latex file (3 pages)+ 2 ps files containing figures. Invited talk at
SUSY96, Maryland, May 199
Using Tau Polarization to Sharpen up the SUGRA Signal at Tevatron
The most promising source of SUGRA signal at the Tevatron collider is the
pair-production of electroweak gauginos, followed by their leptonic decay. In
the parameter range corresponding to dominant leptonic decay of these gauginos
one or more of the leptons are expected to be with .
This polarization can be effectively used to distinguish the signal from the
background in the 1-prong hadronic decay channel of by looking at the
fractional -jet momentum carried by the charged prong.Comment: 11 pages, LateX, 2 figures, discussion on polarization effect added,
final version to be published in PL
Using Tau Polarization as a Distinctive SUGRA Signature at LHC
In the minimal SUGRA model the lighter tau slepton is expected to be the
second lightest superparticle over a large parameter range at large
. Consequently one expects a viable SUGRA signal at LHC in the tau
lepton channel coming from the decay of these tau sleptons. The model predicts
the polarization of this tau lepton to be +1 to a very good accuracy. We show
how this prediction can be tested by looking at the momentum fraction of the
tau-jet, carried by the charged prong, in its 1-prong hadronic decay channel.Comment: 13 pages, 3 figures. Minor changes and one reference added. Version
to be published in PLB. Reprot: TIFR/TH/02-1
Muon Spectra of Quasi-Elastic and 1-Pion Production Events in LBL Neutrino Oscillation Experiments
The muon energy spectra of the quasi-elastic and 1-pion production events in
a LBL experiment, like K2K, are predicted to follow closely the neutrino energy
spectrum, with downward shifts of the energy scale by and respectively. These predictions seem to agree with the
observed muon spectra in the K2K nearby detector. The corresponding muon
spectra in the far-away (SK) detector are predicted to show characteristic
spectral distortions induced by oscillation. Comparison of the
predicted spectral distortions with the observed muon spectra of the 1-Ring and
2-Ring muon events in the SK detector will help to determine the oscillation
parameters. The results will be applicable to other LBL experiments as well.Comment: 13 pages. One figure and a few comments added, final version to
appear in P
- …