arXiv subjects

A. Aranda

Publications and source records attributed to A. Aranda.

8 recordsLinked to original sources

arXiv2021

Latin American HECAP Physics Briefing Book

For the first time the scientific community in Latin America working at the forefront of research in high energy, cosmology and astroparticle physics (HECAP) have come together to discuss and provide scientific input towards the development of a regional strategy. The present document, the Latin American HECAP Physics Briefing Book, is the result of this ambitious bottom-up effort. This report contains the work performed by the Preparatory Group to synthesize the main contributions and discussions for each of the topical working groups. This briefing book discusses the relevant emerging projects developing in the region and considers potentially impactful future initiatives and participation of the Latin American HECAP community in international flagship projects to provide the essential input for the creation of a long-term HECAP strategy in the region.

hep-ex↗

arXiv2019

The $Z_3$ symmetric I(2+1)HDM

We introduce a 3-Higgs Doublet Model (3HDM) with two Inert (or dark) scalar doublets and an active Higgs one, hence termed I(2+1)HDM, in the presence of a discrete $Z_3$ symmetry acting upon the three doublet fields. We show that such a construct yields a Dark Matter (DM) sector with two mass-degenerate states of opposite CP parity, both of which contribute to DM dynamics, which we call \textit{Hermaphrodite DM}, distinguishable from a (single) complex DM candidate. We show that the relic density contributions of both states are equal, saturating the observed relic density compliant with (in)direct searches for DM as well as other experimental data impinging on both the dark and Higgs sectors of the model, chiefly, in the form of Electro-Weak Precision Observables (EWPOs), Standard Model (SM)-like Higgs boson measurements at the Large Hadron Collider (LHC) and void searches for additional (pseudo)scalar states at the CERN machine and previous colliders.

hep-ph↗

arXiv2014

Flavor Physics constrains on a $\mathbb{Z}_5$-3HDM

We present the general behavior of the scalar sector in a Three Higgs Doublet Model (3HDM) with a $\mathbb{Z}_5$ flavor symmetry. There are regions of the parameters space where it is possible to get a SM-like Higgs boson with the other Higgs bosons being heavier, thus decoupled from the SM, and without relevant contributions to any flavor observables. There are however other more interesting regions of parameter space with a light charged Higgs ($m_{H^\pm} \sim $ 150 GeV) that are consistent with experimental results and whose phenomenological consequences could be interesting. We present a numerical analysis of the main $B$-physics constraints and show that the model can correctly describe the current experimental data.

hep-ph↗

arXiv2006

Electroweak-Higgs Unification and the Higgs Boson Mass

We propose an alternative unification scenario where the Higgs self-coupling (lambda) is unified with the electroweak SU(2)L x U(1)Y interactions at an intermediate scale MGH, lower than the GUT scale. In this model the SM remains valid up to this scale MGH, where the gauge and Higgs couplings satisfy the unification condition g1 = g2 = f(lambda). Two variants for this unification condition are discussed; scenario I is defined through the linear relation: g1 = g2 = k lambda(MGH), while scenario II assumes a quadratic relation: g1**2 = g2**2 = k lambda(MGH). An attractive feature of this class of models is the possibility to determine the SM Higgs boson mass by evolving lambda back from MGH down to the electroweak scale; fixing k = O(1) we obtain a Higgs mass value mH approx. 200 GeV. Above MGH, the single coupling gH that describes the electroweak-Higgs interactions, keeps evolving until it unifies with the strong coupling constant. We discuss a realization o this unification scenario within the context of a six-dimensional SU(3)c x SU(3)w Gauge-Higgs unified model.

hep-ph↗

arXiv2004

Physics at the CLIC Multi-TeV Linear Collider

This report summarizes a study of the physics potential of the CLIC e+e- linear collider operating at centre-of-mass energies from 1 TeV to 5 TeV with luminosity of the order of 10^35 cm^-2 s^-1. First, the CLIC collider complex is surveyed, with emphasis on aspects related to its physics capabilities, particularly the luminosity and energy, and also possible polarization, γγand e-e- collisions. The next CLIC Test facility, CTF3, and its R&D programme are also reviewed. We then discuss aspects of experimentation at CLIC, including backgrounds and experimental conditions, and present a conceptual detector design used in the physics analyses, most of which use the nominal CLIC centre-of-mass energy of 3 TeV. CLIC contributions to Higgs physics could include completing the profile of a light Higgs boson by measuring rare decays and reconstructing the Higgs potential, or discovering one or more heavy Higgs bosons, or probing CP violation in the Higgs sector. Turning to physics beyond the Standard Model, CLIC might be able to complete the supersymmetric spectrum and make more precise measurements of sparticles detected previously at the LHC or a lower-energy linear e+e- collider: γγcollisions and polarization would be particularly useful for these tasks. CLIC would also have unique capabilities for probing other possible extensions of the Standard Model, such as theories with extra dimensions or new vector resonances, new contact interactions and models with strong WW scattering at high energies. In all the scenarios we have studied, CLIC would provide significant fundamental physics information beyond that available from the LHC and a lower-energy linear e+e- collider, as a result of its unique combination of high energy and experimental precision.

hep-ph↗

arXiv2004

Les Houches "Physics at TeV Colliders 2003" Beyond the Standard Model Working Group: Summary Report

The work contained herein constitutes a report of the ``Beyond the Standard Model'' working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 26 May--6 June, 2003. The research presented is original, and was performed specifically for the workshop. Tools for calculations in the minimal supersymmetric standard model are presented, including a comparison of the dark matter relic density predicted by public codes. Reconstruction of supersymmetric particle masses at the LHC and a future linear collider facility is examined. Less orthodox supersymmetric signals such as non-pointing photons and R-parity violating signals are studied. Features of extra dimensional models are examined next, including measurement strategies for radions and Higgs', as well as the virtual effects of Kaluza Klein modes of gluons. An LHC search strategy for a heavy top found in many little Higgs model is presented and finally, there is an update on LHC $Z'$ studies.

hep-ph↗

arXiv2003

Where is the Higgs boson?

Electroweak precision measurements indicate that the standard model Higgs boson is light and that it could have already been discovered at LEP 2, or might be found at the Tevatron Run 2. In the context of a TeV^-1 size extra dimensional model, we argue that the Higgs boson production rates at LEP and the Tevatron are suppressed, while they might be enhanced at the LHC or at CLIC. This is due to the possible mixing between brane and bulk components of the Higgs boson, that is, the non-trivial brane-bulk `location' of the lightest Higgs. To parametrize this mixing, we consider two Higgs doublets, one confined to the usual space dimensions and the other propagating in the bulk. Calculating the production and decay rates for the lightest Higgs boson, we find that compared to the standard model (SM), the cross section receives a suppression well below but an enhancement close to and above the compactification scale M_c. This impacts the discovery of the lightest (SM like) Higgs boson at colliders. To find a Higgs signal in this model at the Tevatron Run 2 or at the LC with sqrt(s)=1.5 TeV, a higher luminosity would be required than in the SM case. Meanwhile, at the LHC or at CLIC with sqrt(s) ~ 3-5 TeV one might find highly enhanced production rates. This will enable the latter experiments to distinguish between the extra dimensional and the SM for M_c up to about 6 TeV.

hep-ph↗

arXiv2002

Pion dispersion relation at finite density and temperature

We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature. We introduce a pion chemical potential to describe the finite pion number density and argue that such description is valid during the hadronic phase of a relativistic heavy-ion collision between chemical and thermal freeze-out. We make use of an effective Lagrangian that explicitly respects chiral symmetry through the enforcement of the chiral Ward identities. The pion dispersion relation is computed through the computation of the pion self-energy in a non-perturbative fashion by giving an approximate solution to the Schwinger-Dyson equation for this self-energy. The dispersion relation is described in terms of a density and temperature dependent mass and an index of refraction which is also temperature, density as well as momentum dependent. The index of refraction is larger than unity for all values of the momentum for finite $μ$ and $T$. We conclude by exploring some of the possible consequences for the propagation of pions through the boundary between the medium and vacuum.

hep-ph↗