2,347 research outputs found
Radion-higgs mixing state at the LHC with the KK contributions to the production and decay
In this paper we study the higgs-radion system of the Randall-Sundum model
where matter and gauge fields live in the bulk. We take into account the
Kalza-Klein(KK) loop correction for the higgs and the raidion coupling to the
gauge bosons. Inspired by the LHC data in 2011 where a sign of the higgs boson
has been seen at 125 GeV, we fix the one of the mass eigenstate of the
higgs-radion mixed state at 125 GeV, and scan over all the other parameters
which have not been excluded by the 2011's data. We find the region of
parameters where the scalar particle at 125 GeV have branching ratio larger or
smaller than that of the Standard Model(SM) higgs significantly. The predicted
ratio Br(ZZ)/Br(gamma gamma) also may be different from that of the SM higgs
boson.Comment: 13 pages 6 figure
Implications of Muon anomalous magnetic moment for Direct detection of Neutralino Dark Matter
We investigate the implications of the recent measurement of muon anomalous
magnetic moment for the direct detection of neutralino dark matter in the three
different SUSY models: mSUGRA, a model with non-universal Higgs mass, and an
SO(10) GUT model. We consider two extreme scenario for bound,
i.e. (1 bound)
and ( below). In mSUGRA model,
the counting ratio may be above the sensitivity of the future experiments when
parameters are within bound of . However, the
tends to be high compared to the currently favored value
. For models with the non-universal scalar masses, the possibility
to have the consistent and the high counting ratio is open up
in the region of parameter space where Higgsino mass is smaller than
mSUGRA prediction. In particular, in the SO(10) model, the LSP dark matter
detection rate may be enhanced by almost one order of magnitude compared to
mSUGRA and the model with non-universal Higgs mass, for cosmologically
acceptable . The highest detection rate of LSP dark matter
occurs in the region where the LSP constitutes a subdominant part of local halo
DM. Implication of SUSY mass parameter measurement under the cosmological
constraint is also discussed
Prospects for Spin-1 Resonance Search at 13 TeV LHC and the ATLAS Diboson Excess
Motivated by ATLAS diboson excess around 2 TeV, we investigate a
phenomenology of spin-1 resonances in a model where electroweak sector in the
SM is weakly coupled to strong dynamics. The spin-1 resonances, W' and Z', are
introduced as effective degrees of freedom of the dynamical sector. We explore
several theoretical constraints by investigating the scalar potential of the
model as well as the current bounds from the LHC and precision measurements. It
is found that the main decay modes are V' -> VV and V' -> Vh, and the V' width
is narrow enough so that the ATLAS diboson excess can be explained. In order to
investigate future prospects, we also perform collider simulations at the 13
TeV LHC, and obtain a model independent expected exclusion limit for the
process pp -> W' -> WZ -> JJ. We find a parameter space where the diboson
excess can be explained, and are within a reach of the LHC at the integrated
luminosity of 10 fb-1 and 13 TeV.Comment: 38 pages, 19 figures, 1 table; minor changes, references added,
version published in JHE
Study of stop and sbottom at LHC
In supersymmetric models a gluino can decay into
through a stop or a sbottom. The decay chain produces an edge structure in the
distribution. Monte Carlo simulation studies show that the end point
and the edge height would be measured at the CERN LHC by using a sideband
subtraction technique. The stop and sbottom masses as well as their decay
branching ratios are constrained by the measurement. We study interpretations
of the measurement.Comment: 3 pages, 2 eps files, style files are included, talk at PASCOS'03,
Mumbai, India, January 3-8, 200
Lepton Energy Asymmetry and Precision SUSY study at Hadron Colliders
We study the distribution of lepton pairs from the second lightest neutralino
decay \tilde{\chi}^0_2-->\tilde{l}l followed by \tilde{l}\to \tilde{\chi}^0_1
l. The distribution of the ratio of lepton transverse momenta A_T shows peak
structure if m_{ll}< m^{max}_{ll}/2 is required. The peak position A_T^{peak}
is described by a simple function of the ino and slepton masses in the
m_{ll}\sim 0 limit. When a moderate m_{ll} cut is applied, A_T^{peak} depends
on the \tilde{\chi}^0_2 velocity distribution, but the dependence would be
corrected by studying the lepton P_T distribution. A_T^{peak} and the edge of
m_{ll} distributions are used to determine the mass parameters involved in the
decay for parameters of interest to LHC experiments. For some cases the ino and
slepton masses may be determined within 10% by the lepton distribution only
independent of model assumptions. Correct combinations of A_{T}^{peak} and
m_{ll}^{edge} would be identified even if different \tilde{\chi}^0_2 decay
chains are co-existing. The analysis could be extended to the Tevatron energy
scale or other cascade decays.Comment: 31 pages, 15 figure
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