arXiv subjects

D. Lopez-Val

Publications and source records attributed to D. Lopez-Val.

4 recordsLinked to original sources

arXiv2016

Heavy to light Higgs boson decays at NLO in the Singlet Extension of the Standard Model

We study the decay of a heavy Higgs boson into a light Higgs pair at one loop in the singlet extension of the Standard Model. To this purpose, we construct several renormalization schemes for the extended Higgs sector of the model. We apply these schemes to calculate the heavy-to-light Higgs decay width at next-to-leading order electroweak accuracy, and demonstrate that certain prescriptions lead to gauge-dependent results. We comprehensively examine how the NLO predictions depend on the relevant singlet model parameters, with emphasis on the trademark behavior of the quantum effects, and how these change under different renormalization schemes and a variable renormalization scale. Once all present constraints on the model are included, we find mild NLO corrections, typically of few percent, and with small theoretical uncertainties.

hep-ph↗

arXiv2015

Delta r and the W-boson mass in the Singlet Extension of the Standard Model

The link between the electroweak gauge boson masses and the Fermi constant via the muon lifetime measurement is instrumental for constraining and eventually pinning down new physics. We consider the simplest extension of the Standard Model with an additional real scalar SU(2)_L x U(1)_Y singlet and compute the electroweak precision parameter Delta r, along with the corresponding theoretical prediction for the W-boson mass. When confronted with the experimental W-boson mass measurement, our predictions impose limits on the singlet model parameter space. We identify regions where these correspond to the most stringent experimental constraints that are currently available.

hep-ph↗

arXiv2011

Automized Squark-Neutralino Production to Next-to-Leading Order

The production of one hard jet in association with missing transverse energy is a major LHC search channel motivated by many scenarios for physics beyond the Standard Model. In scenarios with a weakly interacting dark matter candidate, like supersymmetry, it arises from the associated production of a quark partner with the dark matter agent. We present the next-to-leading order cross section calculation as the first application of the fully automized MadGolem package. We find moderate corrections to the production rate with a strongly reduced theory uncertainty.

hep-ph↗

arXiv2006

Ferromagnetic instabilities in neutron matter at finite temperature with the Gogny interaction

The properties of spin polarized neutron matter are studied both at zero and finite temperature using the D1 and the D1P parameterizations of the Gogny interaction. The results show two different behaviors: whereas the D1P force exhibits a ferromagnetic transition at a density of $ρ_c \sim 1.31$ fm$^{-3}$ whose onset increases with temperature, no sign of such a transition is found for D1 at any density and temperature, in agreement with recent microscopic calculations.

nucl-th↗