24 results found
Allanach BC, Camargo-Molina JE, Davighi J, 2021, Global fits of third family hypercharge models to neutral current B-anomalies and electroweak precision observables, EUROPEAN PHYSICAL JOURNAL C, Vol: 81, ISSN: 1434-6044
Athron P, Balazs C, Beniwal A, et al., 2021, Global fits of axion-like particles to XENON1T and astrophysical data, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
Camargo-Molina JE, Markkanen T, Scott P, 2019, Dark energy without fine tuning, The Journal of High Energy Physics, Vol: 44, Pages: 1-14, ISSN: 1029-8479
We present a two-field model that realises inflation and the observed density of dark energy today, whilst solving the fine-tuning problems inherent in quintessence models. One field acts as the inflaton, generically driving the other to a saddle-point of the potential, from which it acts as a quintessence field following electroweak symmetry breaking. The model exhibits essentially no sensitivity to the initial value of the quintessence field, naturally suppresses its interactions with other fields, and automatically endows it with a small effective mass in the late Universe. The magnitude of dark energy today is fixed by the height of the saddle point in the potential, which is dictated entirely by the scale of electroweak symmetry breaking.
Camargo-Molina JE, Morais AP, Ordell A, et al., 2019, Scale hierarchies, symmetry breaking, and particle spectra in SU(3)-family extended SUSY trinification, Physical Review D, Vol: 99, ISSN: 2470-0010
© 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP 3 . A unification of left-right SU(3)L×SU(3)R, color SU(3)C, and family SU(3)F symmetries in a maximal rank-8 subgroup of E8 is proposed as a landmark for future explorations beyond the Standard Model (SM). We discuss the implications of this scheme in a supersymmetric (SUSY) model based on the trinification gauge [SU(3)]3 and global SU(3)F-family symmetries. Among the key properties of this model are the unification of SM Higgs and lepton sectors, a common Yukawa coupling for chiral fermions, the absence of the μ problem, gauge couplings unification, and proton stability to all orders in perturbation theory. The minimal field content consistent with a SM-like effective theory at low energies is composed of one E6 27-plet per generation as well as three gauge and one family SU(3) octets inspired by the fundamental sector of E8. The details of the corresponding (SUSY and gauge) symmetry-breaking scheme, multiscale gauge couplings' evolution, and resulting effective low-energy scenarios are discussed.
Athron P, Balazs C, Beniwal A, et al., 2019, Global analyses of Higgs portal singlet dark matter models using GAMBIT, Publisher: SPRINGER
Camargo-Molina JE, Cells A, Faroughy DA, 2018, Anomalies in bottom from new physics in top, PHYSICS LETTERS B, Vol: 784, Pages: 284-293, ISSN: 0370-2693
Camargo-Molina JE, Mandal T, Pasechnik R, et al., 2018, Heavy charged scalars from c(s)over-bar fusion: a generic search strategy applied to a 3HDM with U(1) x U(1) family symmetry, Journal of High Energy Physics, Vol: 2018, Pages: 1-26, ISSN: 1029-8479
We describe a class of three Higgs doublet models (3HDMs) with a softly broken U(1) × U(1) family symmetry that enforces a Cabibbo-like quark mixing while forbidding tree-level flavour changing neutral currents. The hierarchy in the observed quark masses is partly explained by a softer hierarchy in the vacuum expectation values of the three Higgs doublets. As a consequence, the physical scalar spectrum contains a Standard Model (SM) like Higgs boson h125 while exotic scalars couple the strongest to the second quark family, leading to rather unconventional discovery channels that could be probed at the Large Hadron Collider. In particular, we describe a search strategy for the lightest charged Higgs boson H±, through the process cs⎯⎯→H+→W+h125, using a multivariate analysis that leads to an excellent discriminatory power against the SM background. Although the analysis is applied to the proposed class of 3HDMs, we employ a model-independent formulation such that it can be applied to any other model with the same discovery channel.
Camargo-Molina JE, Morais AP, Ordell A, et al., 2017, Reviving trinification models through an E-6-extended supersymmetric GUT, PHYSICAL REVIEW D, Vol: 95, ISSN: 2470-0010
Camargo-Molina JE, Pasechnik R, Wessen J, 2017, Charged scalars from $SU$$(3)^3$ theories, Proceedings of Prospects for Charged Higgs Discovery at Colliders — PoS(CHARGED2016)
Camargo-Molina JE, Morais AP, Pasechnik R, et al., 2016, On a radiative origin of the Standard Model from trinification, Journal of High Energy Physics, Vol: 2016, ISSN: 1029-8479
In this work, we present a trinification-based grand unified theory incorporating a global SU(3) family symmetry that after a spontaneous breaking leads to a left-right symmetric model. Already at the classical level, this model can accommodate the matter content and the quark Cabbibo mixing in the Standard Model (SM) with only one Yukawa coupling at the unification scale. Considering the minimal low-energy scenario with the least amount of light states, we show that the resulting effective theory enables dynamical breaking of its gauge group down to that of the SM by means of radiative corrections accounted for by the renormalisation group evolution at one loop. This result paves the way for a consistent explanation of the SM breaking scale and fermion mass hierarchies.
Wessen J, Camargo-Molina JE, Pasechnik R, et al., 2016, Radiative origin of the Standard Model from trinification, Fourth Annual Large Hadron Collider Physics, Publisher: Sissa Medialab
Camargo-Molina JE, Morais AP, Pasechnik R, et al., 2016, All one-loop scalar vertices in the effective potential approach, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
Belyaev AS, Camargo-Molina JE, King SF, et al., 2016, A to Z of the muon anomalous magnetic moment in the MSSM with Pati-Salam at the GUT scale, Journal of High Energy Physics, Vol: 2016, Pages: 1-28, ISSN: 1029-8479
We analyse the low energy predictions of the minimal supersymmetric standard model (MSSM) arising from a GUT scale Pati-Salam gauge group further constrained by an A 4 × Z 5 family symmetry, resulting in four soft scalar masses at the GUT scale: one left-handed soft mass m 0 and three right-handed soft masses m 1 , m 2 , m 3, one for each generation. We demonstrate that this model, which was initially developed to describe the neutrino sector, can explain collider and non-collider measurements such as the dark matter relic density, the Higgs boson mass and, in particular, the anomalous magnetic moment of the muon (g − 2) μ . Since about two decades, (g − 2) μ suffers a puzzling about 3σ excessoftheexperimentallymeasuredvalueoverthetheoreticalprediction,whichour model is able to fully resolve. As the consequence of this resolution, our model predicts specific regions of the parameter space with the specific properties including light smuons and neutralinos, which could also potentially explain di-lepton excesses observed by CMS and ATLAS.
We investigate the constrained Minimal Supersymmetric Standard Model (cMSSM) in the light of constraining experimental and observational data from precision measurements, astrophysics, direct supersymmetry searches at the LHC and measurements of the properties of the Higgs boson, by means of a global fit using the program Fittino. As in previous studies, we find rather poor agreement of the best fit point with the global data. We also investigate the stability of the electro-weak vacuum in the preferred region of parameter space around the best fit point. We find that the vacuum is metastable, with a lifetime significantly longer than the age of the Universe. For the first time in a global fit of supersymmetry, we employ a consistent methodology to evaluate the goodness-of-fit of the cMSSM in a frequentist approach by deriving p values from large sets of toy experiments. We analyse analytically and quantitatively the impact of the choice of the observable set on the p value, and in particular its dilution when confronting the model with a large number of barely constraining measurements. Finally, for the preferred sets of observables, we obtain p values for the cMSSM below 10 %, i.e. we exclude the cMSSM as a model at the 90 % confidence level.
Camargo-Molina JE, Wessén J, Pasechnik R, 2016, Charged scalars from SU(3)<sup>3</sup> theories
Inspired by a recently proposed GUT model based on the trinification (SU(3)3) gauge group with a global family (SU(3)F) symmetry, we consider an effective low-energy three Higgs doublet model that may shed light on what underlies the observed fermion mass hierarchies and CKM mixing. We discuss possibilities for charged scalars coming from this model to show in collider experiments and show some interesting benchmark points.
Camargo-Molina JE, Pasechnik R, Wessén J, et al., 2016, On a radiative origin of the standard model in non-supersymmetric trinification with global SU(3)<inf>F</inf>
We present a trinification-based grand unified theory incorporating a global SU(3)F family symmetry, that after spontaneous symmetry breaking leads to a left-right symmetric model. In addition to unification of gauge couplings, the model unifies Yukawa interactions and contains equivalent representations in the scalar and fermion sectors at high energy scales. Considering the minimal low-energy scenario with the least amount of light states, we show that the resulting effective theory enables dynamical breaking of its gauge group to that of the Standard Model by means of radiative corrections accounted for by the renormalisation group evolution at leading order. This result paves the way for a possible explanation of the SM breaking scale and fermion mass hierarchies.
Camargo-Molina JE, Garbrecht B, O'Leary B, et al., 2014, Constraining the Natural MSSM through tunneling to color-breaking vacua at zero and non-zero temperature, PHYSICS LETTERS B, Vol: 737, Pages: 156-161, ISSN: 0370-2693
CAMARGO MOLINA JE, 2014, On the vacuum stability of SUSY models, Proceedings of The European Physical Society Conference on High Energy Physics — PoS(EPS-HEP 2013)
Camargo-Molina JE, O'Leary B, Porod W, et al., 2013, Vevacious: a tool for finding the global minima of one-loop effective potentials with many scalars, EUROPEAN PHYSICAL JOURNAL C, Vol: 73, ISSN: 1434-6044
Camargo-Molina JE, O'Leary B, Porod W, et al., 2013, Stability of R parity in supersymmetric models extended by U(1)(B-L), PHYSICAL REVIEW D, Vol: 88, ISSN: 1550-7998
Camargo-Molina JE, Enberg R, Löfgren J, A new perspective on the electroweak phase transition in the Standard Model Effective Field Theory
A first-order Electroweak Phase Transition (EWPT) could explain the observedbaryon-antibaryon asymmetry and its dynamics could yield a detectablegravitational wave signature, while the underlying physics would be within thereach of colliders. The Standard Model, however, predicts a crossovertransition. We therefore study the EWPT in the Standard Model Effective FieldTheory (SMEFT) including dimension-six operators. A first-order EWPT haspreviously been shown to be possible in the SMEFT. Phenomenology studies havefocused on scenarios with a tree-level barrier between minima, which requires anegative Higgs quartic coupling, and a new physics scale low enough to raisequestions about the validity of the EFT approach. In this work we stress that afirst-order EWPT is also possible when the barrier between minima is generatedradiatively, the quartic coupling is positive, the scale of new physics ishigher, and there is good agreement with experimental bounds. Our calculationis done in a consistent, gauge-invariant way, and we carefully analyze thescaling of parameters necessary to generate a barrier in the potential. Weperform a global fit in the relevant parameter space and explicitly find thepoints with a first-order transition that agree with experimental data. We alsobriefly discuss the prospects for probing the allowed parameter space usingdi-Higgs production in colliders.
AbdusSalam SS, Agocs FJ, Allanach BC, et al., Simple and statistically sound strategies for analysing physical theories
Physical theories that depend on many parameters or are tested against datafrom many different experiments pose unique challenges to parameter estimation.Many models in particle physics, astrophysics and cosmology fall into one orboth of these categories. These issues are often sidestepped with verysimplistic and statistically unsound ad hoc methods, involving naiveintersection of parameter intervals estimated by multiple experiments, andrandom or grid sampling of model parameters. Whilst these methods are easy toapply, they exhibit pathologies even in low-dimensional parameter spaces, andquickly become problematic to use and interpret in higher dimensions. In thisarticle we give clear guidance for going beyond these rudimentary procedures,suggesting some simple methods for performing statistically sound inference,and recommendations of readily-available software tools and standards that canassist in doing so. Our aim is to provide physicists with recommendations forreaching correct scientific conclusions, with only a modest increase inanalysis burden.
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