arXiv subjects

Andres Olivares-Del Campo

Publications and source records attributed to Andres Olivares-Del Campo.

4 recordsLinked to original sources

arXiv2020

Polarisation of high energy gamma-rays after scattering

The polarisation of sunlight after scattering off the atmosphere was first described by Chandrasekhar using a geometrical description of Rayleigh interactions. Kosowsky later extended Chandrasekhar's formalism by using Quantum Field Theory (QFT) to describe the polarisation of the Cosmological Microwave Background radiation. Here we focus on a case that is rarely discussed in the literature, namely the polarisation of high energy radiation after scattering off particles. After demonstrating why the geometrical and low energy QFT approaches fail in this case, we establish the transport formalism that allows to describe the change of polarisation of high energy photons when they propagate through space or the atmosphere. We primarily focus on Compton interactions but our approach is general enough to describe e.g. the scattering of high energy photons off new particles or through new interactions. Finally we determine the conditions for a circularly polarised $γ$--ray signal to keep the same level of circular polarisation as it propagates through its environment.

hep-ph↗

arXiv2018

Implications of a Dark Matter-Neutrino Coupling at Hyper-Kamiokande

Dark matter and neutrinos provide the two most compelling pieces of evidence for new physics beyond the Standard Model of Particle Physics but they are often treated as two different sectors. In this paper, we consider how neutrino observables can be used to constrain the parameter space of different models where active neutrinos interact with DM via mediators of different spins. We study for the first time the sensitivity of the Hyper-Kamiokande detector to neutrinos produced from MeV Dark Matter annihilation. In particular, we find that thermally produced DM candidates with masses between 15-30 MeV could be fully excluded.

hep-ph↗

arXiv2017

Dark matter-neutrino interactions through the lens of their cosmological implications

Dark matter and neutrinos provide the two most compelling pieces of evidence for new physics beyond the Standard Model of Particle Physics but they are often treated as two different sectors. The aim of this paper is to determine whether there are viable particle physics frameworks in which dark matter can be coupled to active neutrinos. We use a simplified model approach to determine all possible renormalizable scenarios where there is such a coupling, and study their astrophysical and cosmological signatures. We find that dark matter-neutrino interactions have an impact on structure formation and lead to indirect detection signatures when the coupling between dark matter and neutrinos is sufficiently large. This can be used to exclude a large fraction of the parameter space. In most cases, dark matter masses up to a few MeV and mediator masses up to a few GeV are ruled out. The exclusion region can be further extended when dark matter is coupled to a spin-1 mediator or when the dark matter particle and the mediator are degenerate in mass if the mediator is a spin-0 or spin-1/2 particle.

hep-ph↗

arXiv2017

Phenomenology of a Neutrino-DM Coupling: The Scalar Case

Dark matter (DM) and neutrinos are the two most compelling pieces of evidence of new physics beyond the Standard Model of Particle Physics but these are often treated as belonging to two different sectors. Yet DM-neutrino interactions are known to have cosmological consequences. Here, we study the scenario of a scalar DM candidate coupled to left-handed neutrinos via a Dirac mediator. We determine the mass of a DM candidate that yields the right DM relic abundance in a thermal scenario and it is consistent with large-scale structure formation. In order to satisfy both constraints, a complex DM candidate should have a mass larger than $8.14$ keV while the mass of a real DM candidate should be above $18.1$ eV, independently of the value of the DM-neutrino coupling.

hep-ph↗