Fileviez Perez, P., Golias, E., Murgui, C., & Plascencia, A. D. (2020). The Higgs and leptophobic force at the LHC. J. High Energy Phys., 07(7), 087–19pp.
Abstract: The Higgs boson could provide the key to discover new physics at the Large Hadron Collider. We investigate novel decays of the Standard Model (SM) Higgs boson into leptophobic gauge bosons which can be light in agreement with all experimental constraints. We study the associated production of the SM Higgs and the leptophobic gauge boson that could be crucial to test the existence of a leptophobic force. Our results demonstrate that it is possible to have a simple gauge extension of the SM at the low scale, without assuming very small couplings and in agreement with all the experimental bounds that can be probed at the LHC.
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Fileviez Perez, P., Murgui, C., & Plascencia, A. D. (2019). The QCD axion and unification. J. High Energy Phys., 11(11), 093–21pp.
Abstract: The QCD axion is one of the most appealing candidates for the dark matter in the Universe. In this article, we discuss the possibility to predict the axion mass in the context of a simple renormalizable grand unified theory where the Peccei-Quinn scale is determined by the unification scale. In this framework, the axion mass is predicted to be in the range ma, <^> (3-13) x 10-9 eV. We study the axion phenomenology and find that the ABRACADABRA and CASPEr-Electric experiments will be able to fully probe this mass window.
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Mandal, R., Murgui, C., Peñuelas, A., & Pich, A. (2020). The role of right-handed neutrinos in b -> c tau nubar anomalies. J. High Energy Phys., 08(8), 022–46pp.
Abstract: Motivated by the persistent anomalies reported in the b -> c tau v<overbar></mml:mover> data, we perform a general model-independent analysis of these transitions, in the presence of light right-handed neutrinos. We adopt an effective field theory approach and write a low-energy effective Hamiltonian, including all possible dimension-six operators. The corresponding Wilson coefficients are determined through a numerical fit to all available experimental data. In order to work with a manageable set of free parameters, we define eleven well- motivated scenarios, characterized by the different types of new physics that could mediate these transitions, and analyse which options seem to be preferred by the current measurements. The data exhibit a clear preference for new-physics contributions, and good fits to the data are obtained in several cases. However, the current measurement of the longitudinal D<SUP></SUP> polarization in B -> D tau v<overbar></mml:mover> cannot be easily accommodated within its experimental 1 sigma range. A general analysis of the three-body B -> D tau v<overbar></mml:mover> and four-body B -> D<mml:mo><mml:mfenced close=“)” open=“(”><mml:mo>-> D pi</mml:mfenced>tau <mml:mover accent=“true”>v<mml:mo stretchy=“true”><overbar></mml:mover> angular distributions is also presented. The accessible angular observables are studied in order to assess their sensitivity to the different new physics scenarios. Experimental information on these distributions would help to disentangle the dynamical origin of the current anomalies.
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