Papers by Renata Zukanovich Funchal
Physical Review D, 1993
We study the constraints on masses and mixing angles imposed by the measured Z invisible width, i... more We study the constraints on masses and mixing angles imposed by the measured Z invisible width, in a model in which a singlet right-handed neutrino mixes with all the standard model neutrinos.
Physical Review Letters, 1999
Flavor changing (FC) neutrino-matter interactions can account for the zenith-angle dependent defi... more Flavor changing (FC) neutrino-matter interactions can account for the zenith-angle dependent deficit of atmospheric neutrinos observed in the SuperKamiokande experiment, without directly invoking neither neutrino mass, nor mixing. We find that FC νµ-matter interactions provide a good fit to the observed zenith angle distributions, comparable in quality to the neutrino oscillation hypothesis. The required FC interactions arise naturally in many attractive extensions of the Standard Model.
Journal of Cosmology and Astroparticle Physics, 2007
In this work we study the phenomenological consequences of the existence of long-range forces cou... more In this work we study the phenomenological consequences of the existence of long-range forces coupled to lepton flavour numbers in solar neutrino oscillations. We study electronic forces mediated by scalar, vector or tensor neutral bosons and analyze their effect on the propagation of solar neutrinos as a function of the force strength and range. Under the assumption of one mass scale dominance, we perform a global analysis of solar and KamLAND neutrino data which depends on the two standard oscillation parameters, ∆m 2 21 and tan 2 θ 12 , the force coupling constant, its range and, for the case of scalar-mediated interactions, on the neutrino mass scale as well. We find that, generically, the inclusion of the new interaction does not lead to a very statistically significant improvement on the description of the data in the most favored MSW LMA (or LMA-I) region. It does, however, substantially improve the fit in the high-∆m 2 LMA (or LMA-II) region which can be allowed for vector and scalar lepto-forces (in this last case if neutrinos are very hierarchical) at 2.5 σ. Conversely, the analysis allows us to place stringent constraints on the strength versus range of the leptonic interaction.
Journal of Physics: Conference Series, 2012
Journal of High Energy Physics
In this paper we study the present and future sensitivities of the rare meson decay facilities KO... more In this paper we study the present and future sensitivities of the rare meson decay facilities KOTO, LHCb and Belle II to a light dark sector of the minimal dark abelian gauge symmetry where a dark Higgs S and a dark photon ZD have masses ≲ 10 GeV. We have explored the interesting scenario where S can only decay to a pair of ZD’s and so contribute to visible or invisible signatures, depending on the life-time of the latter. Our computations show that these accelerator experiments can access the dark Higgs (mass and scalar mixing) and the dark photon (mass and kinetic mixing) parameters in a complementary way. We have also discussed how the CMS measurement of the SM Higgs total decay width and their limit on the Higgs invisible branching ratio can be used to extend the experimental reach to dark photon masses up to ~ 10 GeV, providing at the same time sensitivity to the gauge coupling associated with the broken dark abelian symmetry.
These lecture notes are based on a course given at Institut de Physique Th\'eorique of CEA/Sa... more These lecture notes are based on a course given at Institut de Physique Th\'eorique of CEA/Saclay in January/February 2013.
Cornell University - arXiv, Feb 28, 2019
We comment on Daya Bay's latest definition of the effective ∆m 2 for short baseline reactorνe dis... more We comment on Daya Bay's latest definition of the effective ∆m 2 for short baseline reactorνe disappearance experiments used in [1].
Journal of High Energy Physics
Abelian U(1) gauge group extensions of the Standard Model represent one of the most minimal appro... more Abelian U(1) gauge group extensions of the Standard Model represent one of the most minimal approaches to solve some of the most urgent particle physics questions and provide a rich phenomenology in various experimental searches. In this work, we focus on baryophilic vector mediator models in the MeV-to-GeV mass range and, in particular, present, for the first time, gauge vector field decays into almost arbitrary hadronic final states. Using only very little theoretical approximations, we rigorously follow the vector meson dominance theory in our calculations. We study the effect on the total and partial decay widths, the branching ratios, and not least on the present (future) experimental limits (reach) on (for) the mass and couplings of light vector particles in different models. We compare our results to current results in the literature. Our calculations are publicly available in a python package to compute various vector particle decay quantities in order to describe leptonic a...
in the νe We discuss why high precision measurements of δm 2 atm in the νe / ¯νe disappearance ch... more in the νe We discuss why high precision measurements of δm 2 atm in the νe / ¯νe disappearance channels would high precision measurements that will be performed in be desirable in conjuction with the δm2 atm the νµ and ¯νµ disappearance channels by long baseline experiments such as T2K and NOνA. We show that if these measurements can achieve the challenging precision of about 0.5%, it will be possible to determine the mass hierarchy of the neutrino sector without the need of matter effects.
Lepton flavor violation in exclusive b'SETA's decays
European Physical Journal C, 2016
Starting from the general effective hamiltonian relevant to the b → s transitions, we derive the ... more Starting from the general effective hamiltonian relevant to the b → s transitions, we derive the expressions for the full angular distributions of the B → K (*) 1 2 decay modes, as well as for B(B s → 1 2) (1 = 2). We point out the differences in the treatment of the lepton flavor violating modes with respect to the lepton flavor conserving ones. The relevant Wilson coefficients we evaluate in two different scenarios: (i) The (pseudo-)scalar coefficients are obtained using the (pseudo-)scalar coupling extracted from the experimental non-zero value of B(h → μτ), (ii) we revisit a Z model in which the flavor changing neutral couplings are allowed. We provide the numerical estimates of the branching fractions of the above-mentioned modes in both scenarios.
Journal of High Energy Physics, 2017
We discuss the effect of Beyond the Standard Model charged current interactions on the detection ... more We discuss the effect of Beyond the Standard Model charged current interactions on the detection of the Cosmic Neutrino Background by neutrino capture on tritium in a PTOLEMY-like detector. We show that the total capture rate can be substantially modified for Dirac neutrinos if scalar or tensor right-chiral currents, with strength consistent with current experimental bounds, are at play. We find that the total capture rate for Dirac neutrinos, Γ BSM D , can be between 0.3 to 2.2 of what is expected for Dirac neutrinos in the Standard Model, Γ SM D , so that it can be made as large as the rate expected for Majorana neutrinos with only Standard Model interactions. A non-negligible primordial abundance of right-handed neutrinos can only worsen the situation, increasing Γ BSM D by 30 to 90%. On the other hand, if a much lower total rate is measured than what is expected for Γ SM D , it may be a sign of new physics.
Proceedings of International Europhysics Conference on High Energy Physics — PoS(HEP2005), 2007
We discuss why high precision measurements of δ m 2 atm in the ν e /ν e disappearance channels wo... more We discuss why high precision measurements of δ m 2 atm in the ν e /ν e disappearance channels would be desirable in conjuction with the δ m 2 atm high precision measurements that will be performed in the ν µ andν µ disappearance channels by long baseline experiments such as T2K and NOνA. We show that if these measurements can achieve the challenging precision of about 0.5%, it will be possible to determine the mass hierarchy of the neutrino sector without the need of matter effects.
Journal of High Energy Physics, 2017
In Neutrinophilic Two Higgs Doublet Models, Dirac neutrino masses are obtained by forbidding a Ma... more In Neutrinophilic Two Higgs Doublet Models, Dirac neutrino masses are obtained by forbidding a Majorana mass term for the right-handed neutrinos via a symmetry. We study a variation of such models in which that symmetry is taken to be a local U(1), leading naturally to the typical Lagrangian of the inverse seesaw scenario. The presence of a new gauge boson and of an extended scalar sector result in a rich phenomenology, including modifications to Z, Higgs and kaon decays as well as to electroweak precision parameters, and a pseudoscalar associated to the breaking of lepton number.
Physics Letters B, 2019
Neutrinos may be the harbingers of new dark sectors, since the renormalizable neutrino portal all... more Neutrinos may be the harbingers of new dark sectors, since the renormalizable neutrino portal allows for their interactions with hidden new physics. We propose here to use this fact to connect the generation of neutrino masses to a light dark sector, charged under a new U (1)D dark gauge symmetry. We introduce the minimal number of dark fields to obtain an anomaly free theory with spontaneous breaking of the dark symmetry, and obtain automatically the inverse seesaw Lagrangian. In addition, the so-called µ-term of the inverse seesaw is dynamically generated and technically natural in this framework. As a bonus, the new light dark gauge boson can provide a possible explanation to the MiniBooNE anomaly.
Journal of High Energy Physics, 2019
Neutrino trident scattering is a rare Standard Model process where a charged-lepton pair is produ... more Neutrino trident scattering is a rare Standard Model process where a charged-lepton pair is produced in neutrino-nucleus scattering. To date, only the dimuon final-state has been observed, with around 100 total events, while the other channels are as yet unexplored. In this work, we compute the trident production cross section by performing a complete four-body phase space calculation for different hadronic targets. This provides a correct estimate both of the coherent and the diffractive contributions to these cross sections, but also allows us to address certain inconsistencies in the literature related to the use of the Equivalent Photon Approximation in this context. We show that this approximation can give a reasonable estimate only for the production of dimuon final-states in coherent scattering, being inadmissible for all other cases considered. We provide estimates of the number and distribution of trident events at several current and future near detector facilities subject...
Physical Review Letters, 2018
We present a novel framework that provides an explanation to the long-standing excess of electron... more We present a novel framework that provides an explanation to the long-standing excess of electronlike events in the MiniBooNE experiment at Fermilab. We suggest a new dark sector containing a dark neutrino and a dark gauge boson, both with masses between a few tens and a few hundreds of MeV. Dark neutrinos are produced via neutrino-nucleus scattering, followed by their decay to the dark gauge boson, which in turn gives rise to electron-like events. This mechanism provides an excellent fit to MiniBooNE energy spectra and angular distributions.
Journal of High Energy Physics, 2018
The detection of coherent neutrino-nucleus scattering by the COHERENT collaboration has set on qu... more The detection of coherent neutrino-nucleus scattering by the COHERENT collaboration has set on quantitative grounds the existence of an irreducible neutrino background in direct detection searches of Weakly Interacting Massive Dark Matter candidates. This background leads to an ultimate discovery limit for these experiments: a minimum Dark Matter interaction cross section below which events produced by the coherent neutrino scattering will mimic the Dark Matter signal, the so-called neutrino floor. In this work we study the modification of such neutrino floor induced by non-standard neutrino interactions within their presently allowed values by the global analysis of oscillation and COHERENT data. By using the full likelihood information of such global analysis we consistently account for the correlated effects of non-standard neutrino interactions both in the neutrino propagation in matter and in its interaction in the detector. We quantify their impact on the neutrino floor for fi...
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Papers by Renata Zukanovich Funchal