2,075 research outputs found
Imprints of massive inverse seesaw model neutrinos in lepton flavor violating Higgs boson decays
In this paper we consider a Higgs boson with mass and other properties
compatible with those of the recently discovered Higgs particle at the LHC, and
explore the possibility of new Higgs leptonic decays, beyond the standard
model, with the singular feature of being lepton flavor violating (LFV). We
study these LFV Higgs decays, , within the context of the
inverse seesaw model (ISS) and consider the most generic case where three
additional pairs of massive right-handed singlet neutrinos are added to the
standard model particle content. We require in addition that the input
parameters of this ISS model are compatible with the present neutrino data and
other constraints, like perturbativity of the neutrino Yukawa couplings. We
present a full one-loop computation of the BR() rates for
the three possible channels, , and analyze in full detail the predictions as functions of the
various relevant ISS parameters. We study in parallel the correlated one-loop
predictions for the radiative decays, , within this same
ISS context, and require full compatibility of our predictions with the present
experimental bounds for the three radiative decays, , , and . After exploring the ISS parameter
space we conclude on the maximum allowed LFV Higgs decay rates within the ISS.Comment: 29 pages, 13 figures, 1 table, 1 appendix: v4 matches the manuscript
published in PR
Exotic events from heavy ISS neutrinos at the LHC
In this letter we study new relevant phenomenological consequences of the
right-handed heavy neutrinos with masses at the TeV energy scale,
working within the context of the Inverse Seesaw Model that includes three
pairs of quasi-degenerate pseudo-Dirac heavy neutrinos. We propose a new exotic
signal of these heavy neutrinos at the CERN Large Hadron Collider containing a
muon, a tau lepton, and two jets in the final state, which is based on the
interesting fact that this model can incorporate large Lepton Flavor Violation
for specific choices of the relevant parameters, particularly, the neutrino
Yukawa couplings. We will show here that an observable number of
exotic events, without missing energy, can be produced at this ongoing run of
the LHC.Comment: 7 pages, 4 figures. This version v3 matches the manuscript published
in Physics Letters
Charged lepton flavour violation from low scale seesaw neutrinos
In the work presented here, we have studied the impact of right handed
neutrinos, which are introduced to account for the evidence of neutrino masses,
on charged lepton flavour violating observables. In particular, we have focused
on the loop induced decays of the Z boson into two leptons of different
flavour. We have performed a numerical study of the rates predicted for these
processes within the Inverse Seesaw model, specifically considering scenarios
where transitions are suppressed. Our conclusion, after comparison
with the most relevant experimental constraints, is that branching ratios as
large as can be predicted in the or
channels, together with heavy neutrinos having masses of the TeV order. Such
rates could be accessible at next generation colliders.Comment: 13 pages, 5 figures, 3 tables. Proceedings of the Corfu Summer
Institute 2016 "School and Workshops on Elementary Particle Physics and
Gravity", 31 August - 23 September 2016, Corfu, Greec
Radiative corrections to from three generations of Majorana neutrinos and sneutrinos
In this work we study the radiative corrections to the mass of the lightest
Higgs boson of the MSSM from three generations of Majorana neutrinos and
sneutrinos. The spectrum of the MSSM is augmented by three right handed
neutrinos and their supersymmetric partners. A seesaw mechanism of type I is
used to generate the physical neutrino masses and oscillations that we require
to be in agreement with present neutrino data. We present a full one-loop
computation of these Higgs mass corrections, and analyze in full detail their
numerical size in terms of both the MSSM and the new (s)neutrino parameters. A
critical discussion on the different possible renormalization schemes and their
implications is included.Comment: 42 pages, 39 figures, 1 appendix, version published in AHE
Collider phenomenology of vector resonances in WZ scattering processes
We study the production of vector resonances at the LHC via scattering
processes and explore the sensitivities to these resonances for the expected
future LHC luminosities. The electroweak chiral Lagrangian and the Inverse
Amplitude Method (IAM) are used for analyzing a dynamically generated vector
resonance, whose origin would be the (hypothetically strong) self interactions
of the longitudinal gauge bosons, and . We implement the unitarized
scattering amplitudes into a single model, the IAM-MC, that has been adapted to
MadGraph~5. It is written in terms of the electroweak chiral Lagrangian and an
additional effective Proca Lagrangian for the vector resonances, so that it
reproduces the resonant behavior of the IAM and allows us to perform a
realistic study of signal versus background at the LHC. We focus on the channel, discussing first on the potential of the hadronic and
semileptonic channels of the final , and next exploring in more detail the
clearest signals. These are provided by the leptonic decays of the gauge
bosons, leading to a final state with , ,
having a very distinctive signature, and showing clearly the emergence of the
resonances with masses in the range of -, which we have
explored.Comment: 8 pages, 5 figures, contributed to the XIII Quark Confinement and the
Hadron Spectrum - Confinement2018, 31 July - 6 August 2018, Maynooth
University, Irelan
Production of vector resonances at the LHC via WZ-scattering: a unitarized EChL analysis
In the present work we study the production of vector resonances at the LHC
by means of the vector boson scattering and explore the
sensitivities to these resonances for the expected future LHC luminosities. We
are assuming that these vector resonances are generated dynamically from the
self interactions of the longitudinal gauge bosons, and , and work
under the framework of the electroweak chiral Lagrangian to describe in a model
independent way the supposedly strong dynamics of these modes. The properties
of the vector resonances, mass, width and couplings to the and gauge
bosons are derived from the inverse amplitude method approach. We implement all
these features into a single model, the IAM-MC, adapted for MonteCarlo, built
in a Lagrangian language in terms of the electroweak chiral Lagrangian and a
chiral Lagrangian for the vector resonances, which mimics the resonant behavior
of the IAM and provides unitary amplitudes. The model has been implemented in
MadGraph, allowing us to perform a realistic study of the signal versus
background events at the LHC. In particular, we have focused our study on the
type of events, discussing first on the potential of the hadronic
and semileptonic channels of the final , and next exploring in more detail
the clearest signals. These are provided by the leptonic decays of the gauge
bosons, leading to a final state with ,
, having a very distinctive signature, and showing clearly the
emergence of the resonances with masses in the range of 1.5-2.5 TeV, which we
have explored.Comment: Revised version accepted for publication in JHEP. Enlarged analysis.
References added. 44 pages, 23 figures, 3 table
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