
Aebischer, J. et al, & Vicente, A. (2024). Computing tools for effective field theories. Eur. Phys. J. C, 84(2), 170–59pp.
Abstract: In recent years, theoretical and phenomenological studies with effective field theories have become a trending and prolific line of research in the field of highenergy physics. In order to discuss present and future prospects concerning automated tools in this field, the SMEFTTools 2022 workshop was held at the University of Zurich from 14th16th September 2022. The current document collects and summarizes the content of this workshop.



Aebischer, J., Brivio, I., Celis, A., Evans, J. A., Jiang, Y., Kumar, J., et al. (2018). WCxf : An exchange format for Wilson coefficients beyond the Standard Model. Comput. Phys. Commun., 232, 71–83.
Abstract: We define a data exchange format for numerical values of Wilson coefficients of local operators parameterising lowenergy effects of physics beyond the Standard Model. The format facilitates interfacing modelspecific Wilson coefficient calculators, renormalisation group (RG) runners, and observable calculators. It is designed to be unambiguous (defining a nonredundant set of operators with fixed normalisation in each basis), extensible (allowing the addition of new EFTs or bases by the user), and robust (being based on industry standard file formats with parsers implemented in many programming languages). We have implemented the format for the Standard Model EFT (SMEFT) and for the weak effective theory (WET) below the electroweak scale and have added interfaces to a number of public codes dealing with SMEFT or WET. We also provide commandline utilities and a Python module for convenient manipulation of WCxf files, including translation between different bases and matching from SMEFT to WET. (C) 2018 Elsevier B.V. All rights reserved.



Aoki, M., Toma, T., & Vicente, A. (2015). Nonthermal production of minimal dark matter via righthanded neutrino decay. J. Cosmol. Astropart. Phys., 09(9), 063–19pp.
Abstract: Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and coannihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three righthanded neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2)(L) quintuplet and a scalar SU(2)(L) septuplet. The lightest righthanded neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freezein. This creates a link between dark matter and neutrino physics: dark matter can be nonthermally produced by the decay of the lightest righthanded neutrino after freezeout, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the nonthermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gammaray observations.



Aristizabal Sierra, D., HerreroGarcia, J., Restrepo, D., & Vicente, A. (2016). Diboson anomaly: Heavy Higgs resonance and QCD vectorlike exotics. Phys. Rev. D, 93(1), 015012–12pp.
Abstract: The ATLAS Collaboration (and also CMS) has recently reported an excess over Standard Model expectations for gauge boson pair production in the invariant mass region 1.82.2 TeV. In light of these results, we argue that such a signal might be the first manifestation of the production and further decay of a heavy CPeven Higgs resulting from a typeI two Higgs doublet model. We demonstrate that in the presence of colored vectorlike fermions, its gluon fusion production cross section is strongly enhanced, with the enhancement depending on the color representation of the new fermion states. Our findings show that barring the color triplet case, any QCD “exotic” representation can fit the ATLAS result in fairly large portions of the parameter space. We have found that if the diboson excess is confirmed and this mechanism is indeed responsible for it, then the LHC Run2 should find (i) a CPodd scalar with mass below similar to 2.3 TeV, (ii) new colored states with masses below similar to 2 TeV, (iii) no statistically significant diboson events in the W(+/)Z channel, (iv) events in the triboson channels W(+/)W(/+)Z and ZZZ with invariant mass amounting to the mass of the CPodd scalar.



Aristizabal Sierra, D., Staub, F., & Vicente, A. (2015). Shedding light on the b > s anomalies with a dark sector. Phys. Rev. D, 92(1), 015001–11pp.
Abstract: The LHCb Collaboration has recently reported on some anomalies in b > s transitions. In addition to discrepancies with the Standard Model (SM) predictions in some angular observables and branching ratios, an intriguing hint for lepton universality violation was found. Here we propose a simple model that extends the SM with a dark sector charged under an additional U(1) gauge symmetry. The spontaneous breaking of this symmetry gives rise to a massive Z' boson, which communicates the SM particles with a valid dark matter candidate, while solving the b > s anomalies with contributions to the relevant observables.



Aristizabal Sierra, D., Tortola, M., Valle, J. W. F., & Vicente, A. (2014). Leptogenesis with a dynamical seesaw scale. J. Cosmol. Astropart. Phys., 07(7), 052–20pp.
Abstract: In the simplest typeI seesaw leptogenesis scenario righthanded neutrino annihilation processes are absent. However, in the presence of new interactions these processes are possible and can affect the resulting B – L asymmetry in an important way. A prominent example is provided by models with spontaneous lepton number violation, where the existence of new dynamical degrees of freedom can play a crucial role. In this context, we provide a modelindependent discussion of the effects of righthanded neutrino annihilations. We show that in the weak washout regime, as long as the scattering processes remain slow compared with the Hubble expansion rate throughout the relevant temperature range, the efficiency can be largely enhanced, reaching in some cases maximal values. Moreover, the B – L asymmetry yield turns out to be independent upon initial conditions, in contrast to the “standard” case. On the other hand, when the annihilation processes are fast, the righthanded neutrino distribution tends to a thermal one down to low temperatures, implying a drastic suppression of the efficiency which in some cases can render the B – L generation mechanism inoperative.



Bazzocchi, F., Morisi, S., Peinado, E., Valle, J. W. F., & Vicente, A. (2013). Bilinear Rparity violation with flavor symmetry. J. High Energy Phys., 01(1), 033–16pp.
Abstract: Bilinear Rparity violation (BRPV) provides the simplest intrinsically supersymmetric neutrino mass generation scheme. While neutrino mixing parameters can be probed in high energy accelerators, they are unfortunately not predicted by the theory. Here we propose a model based on the discrete flavor symmetry Lambda(4) with a single Rparity violating parameter, leading to (i) correct Cabbibo mixing given by the GattoSartoriTonin formula, and a successful unificationlike btau mass relation, and (ii) a correlation between the lepton mixing angles theta(13) and theta(23) in agreement with recent neutrino oscillation data, as well as a (nearly) massless neutrino, leading to absence of neutrinoless double beta decay.



Boucenna, S. M., Celis, A., FuentesMartin, J., Vicente, A., & Virto, J. (2016). Phenomenology of an SU(2) x SU(2) x U(1) model with leptonflavour nonuniversality. J. High Energy Phys., 12(12), 059–43pp.
Abstract: We investigate a gauge extension of the Standard Model in light of the observed hints of lepton universality violation in b > clv and b > sl(+) l() decays at BaBar, Belle and LHCb. The model consists of an extended gauge group SU(2)(1) x SU(2)(2) x U(l)(Y) which breaks spontaneously around the TeV scale to the electroweak gauge group. Fermion mixing effects with vector like fermions give rise to potentially large new physics contributions in flavour transitions mediated by WI and Z' bosons. This model can ease tensions in B physics data while satisfying stringent bounds from flavour physics, and electroweak precision data. Possible ways to test the proposed new physics scenario with upcoming experimental measurements are discussed. Among other predictions, the ratios RM =Gamma(B > M mu(+)mu())/Gamma(B > Me(+)e()), with M = K*, phi, are found to be reduced with respect to the Standard Model expectation RM similar or equal to 1.



Boucenna, S. M., Celis, A., FuentesMartin, J., Vicente, A., & Virto, J. (2016). Nonabelian gauge extensions for Bdecay anomalies. Phys. Lett. B, 760, 214–219.
Abstract: We study the generic features of minimal gauge extensions of the Standard Model in view of recent hints of leptonflavor nonuniversality in semileptonic b > sl(+)l() and b > cl nu decays. We classify the possible models according to the symmetrybreaking pattern and the source of flavor nonuniversality. We find that in viable models the SU(2)(L) factor is embedded nontrivially in the extended gauge group, and that gauge couplings should be universal, hinting to the presence of new degrees of freedom sourcing nonuniversality. Finally, we provide an explicit model that can explain the Bdecay anomalies in a coherent way and confront it with the relevant phenomenological constraints.



Boucenna, S. M., Morisi, S., & Vicente, A. (2016). LHC diphoton resonance from gauge symmetry. Phys. Rev. D, 93(11), 115008–8pp.
Abstract: Motivated by what is possibly the first sign of new physics seen at the LHC, the diphoton excess at 750 GeV in ATLAS and CMS, we present a model that provides naturally the necessary ingredients to explain the resonance. The simplest phenomenological explanation for the diphoton excess requires a new scalar state, X(750), as well as additional vectorlike (VL) fermions introduced in an adhoc way in order to enhance its decays into a pair of photons and/or increase its production cross section. We show that the necessary VL quarks and their couplings can emerge naturally from a complete framework based on the SU(3)(L) circle times U(1)(X) gauge symmetry.

