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José W. F. Valle

Publications and source records attributed to José W. F. Valle.

80 records · Page 5Linked to original sources
arXiv2016

Electroweak breaking and neutrino mass: "invisible" Higgs decays at the LHC (Type II seesaw)

Neutrino mass generation through the Higgs mechanism not only suggests the need to reconsider the physics of electroweak symmetry breaking from a new perspective, but also provides a new theoretically consistent and experimentally viable paradigm. We illustrate this by describing the main features of the electroweak symmetry breaking sector of the simplest type-II seesaw model with spontaneous breaking of lepton number. After reviewing the relevant "theoretical" and astrophysical restrictions on the Higgs sector, we perform an analysis of the sensitivities of Higgs boson searches at the ongoing ATLAS and CMS experiments at the LHC, including not only the new contributions to the decay channels present in the Standard Model (SM) but also genuinely non-SM Higgs boson decays, such as "invisible" Higgs boson decays to majorons. We find sensitivities that are likely to be reached at the upcoming Run of the experiments.

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arXiv2016

Consistency of WIMP Dark Matter as radiative neutrino mass messenger

The scotogenic scenario provides an attractive approach to both Dark Matter and neutrino mass generation, in which the same symmetry that stabilises Dark Matter also ensures the radiative seesaw origin of neutrino mass. However the simplest scenario may suffer from inconsistencies arising from the spontaneous breaking of the underlying $\mathbb{Z}_2$ symmetry. Here we show that the singlet-triplet extension of the simplest model naturally avoids this problem due to the presence of scalar triplets neutral under the $\mathbb{Z}_2$ which affect the evolution of the couplings in the scalar sector. The scenario offers good prospects for direct WIMP Dark Matter detection through the nuclear recoil method.

hep-ph↗
arXiv2016

Dynamical seesaw mechanism for Dirac neutrinos

So far we have not been able to establish that, as theoretically expected, neutrinos are their own anti-particles. Here we propose a dynamical way to account for the Dirac nature of neutrinos and the smallness of their mass in terms of a new variant of the seesaw paradigm in which the energy scale of neutrino mass generation could be accessible to the current LHC experiments.

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arXiv2015

Consistency of the triplet seesaw model revisited

Adding a scalar triplet to the Standard Model is one of the simplest ways of giving mass to neutrinos, providing at the same time a mechanism to stabilize the theory's vacuum. In this paper, we revisit these aspects of the type-II seesaw model pointing out that the bounded-from-below conditions for the scalar potential in use in the literature are not correct. We discuss some scenarios where the correction can be significant and sketch the typical scalar boson profile expected by consistency.

hep-ph↗
arXiv1995

Novel Scalar Boson Decays in SUSY with Broken R-Parity

R parity violation can induce mixing of the supersymmetric Higgs bosons with the sneutrinos at the tree level. We study the effect of this mixing on the decays of Higgs scalars as well as sneutrinos in an effective model where the violation of R parity is included in the minimal supersymmetric model through bilinear lepton number violating superpotential terms. We show that a small violation of R parity can lead to a sizeable branching ratio for the supersymmetric Higgs boson decay mode $H \to χ\ell$ (where $χ$ denotes an electroweak gaugino and $\ell$ is either a tau neutrino or a tau lepton). Relevant constraints on R parity violation as well as those coming from SUSY particle searches still allow the decay $H \to χ\ell$ to compete with the conventional decay $H\ra b \bar{b}$, at least for some ranges of parameters of the model. Moreover, the tau sneutrino will have dominant R parity violating decays to standard model fermions $b \bar{b}$, $τ^+ τ^-$ or to the invisible mode $ν\barν$ whenever the phase space for R parity conserving channels is closed.

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arXiv1995

SIGNATURES FROM PHYSICS BEYOND THE STANDARD MODEL

A brief review is made of some of the experimental signatures that may be associated to a certain class of extensions of the standard model. The material of these lectures is divided into two sections. After briefly sketching the present observational status of the neutrino masses I consider various schemes of neutrino mass generation, including those which are motivated by present experimental hints from solar and atmospheric neutrinos, as well as cosmological data on the amplitude of primordial density fluctuations. Then some of the physics motivations and potential of various extensions of the standard model related to the electroweak breaking sector, such as supersymmetry, and extensions of the gauge boson sector are reviewed. The new signatures associated with both types of extension may all be accessible to experiments performed either at accelerators or at underground installations. The complementarity between these two approaches in the search for signals beyond the standard model is most vividly manifest in the field of neutrino physics.

hep-ph↗
arXiv1994

Recent Results in Neutrino Physics

Invited Talk at {\sl ICNAPP}, Bangalore, India, Jan. 1994; {\sl Int. School on Cosmological Dark Matter}, Valencia, Oct. 1993; and Gran Sasso meeting on {\sl Solar Neutrino Problem: astrophysics or oscillations?}, march 1994.

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