28 research outputs found
Some implications of lepton flavor violating processes in a supersymmetric Type II seesaw model at TeV scale
We have conceived a supersymmetric Type II seesaw model at TeV scale, which
has some additional particles consisting of scalar and fermionic triplet Higgs
states, whose masses being around few hundred GeV. In this particular model, we
have studied constraints on the masses of triplet states arising from the
lepton flavor violating (LFV) processes, such as and . We have analyzed the implications of these constraints on other
observable quantities such as the muon anomalous magnetic moment and the decay
patterns of scalar triplet Higgses. Scalar triplet Higgs states can decay into
leptons and into supersymmetric fields. We have found that the constraints from
LFV can effect these various decay modes.Comment: 32 pages, 13 figures, 3 tables, a new section on detection prospects
of the model and references are added, sharpened the content of the paper but
conclusions are unchanged; accepted by Eur. Phys. J.
Muon (g-2) from the bulk neutrino field in a warped extra dimensional model
In the Randall-Sundrum model, a bulk neutrino field in the 5-dimensional
space-time can give rise to tiny Dirac masses to neutrinos. In such a scenario,
we have computed the contribution of the bulk neutrino field to the anomalous
magnetic moment of muon. We have computed this contribution in the
't Hooft-Feynman gauge and have found that the contribution has the right sign
to fit the current discrepancy between the experiment and the standard model
value of . We have also studied possible constraints on the model
parameters by including contributions to from other sources such as
bulk gravitons.Comment: 18 pages, 3 figures, 2 tables, minor changes, this version has been
published in Physical Review
Implications of Higgs to diphoton decay rate in the bilinear R-parity violating supersymmetric model
The Large Hadron Collider has recently discovered a Higgs-like particle
having a mass around 125 GeV and also indicated that there is an enhancement in
the Higgs to diphoton decay rate as compared to that in the standard model. We
have studied implications of these discoveries in the bilinear R-parity
violating supersymmetric model, whose main motivation is to explain the
non-zero masses for neutrinos. The R-parity violating parameters in this model
are and , and these parameters determine the scale of
neutrino masses. If the enhancement in the Higgs to diphoton decay rate is
true, then we have found \epsilon\gapprox 0.01 GeV and 1
GeV in order to be compatible with the neutrino oscillation data. Also, in
the above mentioned analysis, we can determine the soft masses of sleptons
() and CP-odd Higgs boson mass (). We have estimated that
m_L\gapprox 300 GeV and m_A\gapprox 700 GeV. We have also commented on the
allowed values of and , in case there is no enhancement
in the Higgs to diphoton decay rate. Finally, we present a model to explain the
smallness of and .Comment: 23 pages, 10 eps figures, minor changes, new references added,
accepted by Physical Review
Bulk Higgs and Gauge fields in a multiply warped braneworld model
We readdress the problems associated with bulk Higgs and the gauge fields in
a 5-dimensional Randall-Sundrum model by extending the model to six dimensions
with double warping along the two extra spatial dimensions. In this
6-dimensional model we have a freedom of two moduli scales as against one
modulus in the 5-dimensional model. With a little hierarchy between these
moduli we can obtain the right magnitude for and boson masses from the
Kaluza-Klein modes of massive bulk gauge fields where the spontaneous symmetry
breaking is triggered by bulk Higgs . We also have determined the gauge
couplings of the standard model fermions with Kaluza-Klein modes of the gauge
fields. Unlike the case of 5-dimensional model with a massless bulk gauge
field, here we have shown that the gauge couplings and the masses of the
Kaluza-Klein gauge fields satisfy the precision electroweak constraints and
also obey the Tevatron bounds.Comment: 15 Pages, Late
Addressing \mu-b_\mu and proton lifetime problems and active neutrino masses in a U(1)^\prime-extended supergravity model
We present a locally supersymmetric extension of the minimal supersymmetric
Standard Model (MSSM) based on the gauge group where, except for the supersymmetry breaking scale
which is fixed to be GeV, we require that all non-Standard-Model
parameters allowed by the {\it local} spacetime and gauge symmetries assume
their natural values. The symmetry, which is spontaneously broken
at the intermediate scale, serves to ({\it i}) explain the weak scale
magnitudes of and terms, ({\it ii}) ensure that dimension-3 and
dimension-4 baryon-number-violating superpotential operators are forbidden,
solving the proton-lifetime problem, ({\it iii}) predict {\it bilinear lepton
number violation} in the superpotential at just the right level to accommodate
the observed mass and mixing pattern of active neutrinos (leading to a novel
connection between the SUSY breaking scale and neutrino masses), while
corresponding trilinear operators are strongly supppressed. The phenomenology
is like that of the MSSM with bilinear R-parity violation, were the would-be
lightest supersymmetric particle decays leptonically with a lifetime of s. Theoretical consistency of our model requires the
existence of multi-TeV, stable, colour-triplet, weak-isosinglet scalars or
fermions, with either conventional or exotic electric charge which should be
readily detectable if they are within the kinematic reach of a hadron collider.
Null results of searches for heavy exotic isotopes implies that the re-heating
temperature of our Universe must have been below their mass scale which, in
turn, suggests that sphalerons play a key role for baryogensis. Finally, the
dark matter cannot be the weakly interacting neutralino.Comment: 33 pages, 2 figures, Discussion on proton decay and radiative
neutrino masses augmented, and references adde
Neutrino masses along with fermion mass hierarchy
Recently a new mechanism has been proposed to cure the problem of fermion
mass hierarchy in the Standard Model (SM) model. In this scenario, all SM
charged fermions other than top quark arise from higher dimensional operators
involving the SM Higgs field. This model also predicted some interesting
phenomenology of the Higgs boson. We generalize this model to accommodate
neutrino masses (Dirac & Majorana) and also obtain the mixing pattern in the
leptonic sector. To generate neutrino masses, we add extra three right handed
neutrinos in this model.Comment: 20 pages, the content on results and phenomenology have been
expanded, a new section on UV completion of the model has been added and also
some new references, this version has been accepted by Physical Review