|
|
Bellomo, N., Bellini, E., Hu, B., Jimenez, R., Pena-Garay, C., & Verde, L. (2017). Hiding neutrino mass in modified gravity cosmologies. J. Cosmol. Astropart. Phys., 02(2), 043–12pp.
Abstract: Cosmological observables show a dependence with the neutrino mass, which is partially degenerate with parameters of extended models of gravity. We study and explore this degeneracy in Horndeski generalized scalar-tensor theories of gravity. Using forecasted cosmic microwave background and galaxy power spectrum datasets, we find that a single parameter in the linear regime of the effective theory dominates the correlation with the total neutrino mass. For any given mass, a particular value of this parameter approximately cancels the power suppression due to the neutrino mass at a given redshift. The extent of the cancellation of this degeneracy depends on the cosmological large-scale structure data used at different redshifts. We constrain the parameters and functions of the effective gravity theory and determine the influence of gravity on the determination of the neutrino mass from present and future surveys.
|
|
|
|
Double Chooz collaboration(Abrahao, T. et al), & Novella, P. (2021). Reactor rate modulation oscillation analysis with two detectors in Double Chooz. J. High Energy Phys., 01(1), 190–18pp.
Abstract: A theta (13) oscillation analysis based on the observed antineutrino rates at the Double Chooz far and near detectors for different reactor power conditions is presented. This approach provides a so far unique simultaneous determination of theta (13) and the total background rates without relying on any assumptions on the specific background contributions. The analysis comprises 865 days of data collected in both detectors with at least one reactor in operation. The oscillation results are enhanced by the use of 24.06 days (12.74 days) of reactor-off data in the far (near) detector. The analysis considers the nu <mml:mo stretchy=“true”><overbar></mml:mover>e interactions up to a visible energy of 8.5 MeV, using the events at higher energies to build a cosmogenic background model considering fast-neutrons interactions and Li-9 decays. The background-model-independent determination of the mixing angle yields sin(2)(2 theta (13)) = 0.094 0.017, being the best-fit total background rates fully consistent with the cosmogenic background model. A second oscillation analysis is also performed constraining the total background rates to the cosmogenic background estimates. While the central value is not significantly modified due to the consistency between the reactor-off data and the background estimates, the addition of the background model reduces the uncertainty on theta (13) to 0.015. Along with the oscillation results, the normalization of the anti-neutrino rate is measured with a precision of 0.86%, reducing the 1.43% uncertainty associated to the expectation.
|
|
|
|
ANTARES Collaboration(Aguilar, J. A. et al), Bigongiari, C., Dornic, D., Emanuele, U., Gomez-Gonzalez, J. P., Hernandez-Rey, J. J., et al. (2010). Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector. Astropart Phys., 34(3), 179–184.
Abstract: The ANTARES high-energy neutrino telescope is a three-dimensional array of about 900 photomultipliers distributed over 12 mooring lines installed in the Mediterranean Sea. Between February and November 2007 it acquired data in a 5-line configuration. The zenith angular distribution of the atmospheric muon flux and the associated depth-intensity relation are measured and compared with previous measurements and Monte Carlo expectations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is presented.
|
|
|
|
ANTARES Collaboration(Aguilar, J. A. et al), Bigongiari, C., Dornic, D., Emanuele, U., Gomez-Gonzalez, J. P., Hernandez-Rey, J. J., et al. (2011). Search for a diffuse flux of high-energy nu(mu) with the ANTARES neutrino telescope. Phys. Lett. B, 696(1-2), 16–22.
Abstract: A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A (0.83 x 2 pi) sr sky was monitored for a total of 334 days of equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an E-2 flux spectrum, a 90% c.l. upper limit on the diffuse nu(mu) flux of E-2 Phi(90%) = 5.3 x 10(-8) GeV cm(-2) s(-1) sr(-1) in the energy range 20 TeV-2.5 PeV is obtained. Other signal models with different energy spectra are also tested and some rejected.
|
|
|
|
Bazzocchi, F., Morisi, S., Peinado, E., Valle, J. W. F., & Vicente, A. (2013). Bilinear R-parity violation with flavor symmetry. J. High Energy Phys., 01(1), 033–16pp.
Abstract: Bilinear R-parity 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 R-parity violating parameter, leading to (i) correct Cabbibo mixing given by the Gatto-Sartori-Tonin formula, and a successful unification-like b-tau 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.
|
|
|
|
Baxter, D., Collar, J. I., Coloma, P., Dahl, C. E., Esteban, I., Ferrario, P., et al. (2020). Coherent elastic neutrino-nucleus scattering at the European Spallation Source. J. High Energy Phys., 02(2), 123–38pp.
Abstract: The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it will also generate the largest pulsed neutrino flux suitable for the detection of Coherent Elastic Neutrino-Nucleus Scattering (CE nu NS), a process recently measured for the first time at ORNL's Spallation Neutron Source. We describe innovative detector technologies maximally able to profit from the order-of-magnitude increase in neutrino flux provided by the ESS, along with their sensitivity to a rich particle physics phenomenology accessible through high-statistics, precision CE nu NS measurements.
|
|
|
|
Batra, A., Bharadwaj, P., Mandal, S., Srivastava, R., & Valle, J. W. F. (2023). Phenomenology of the simplest linear seesaw mechanism. J. High Energy Phys., 07(7), 221–48pp.
Abstract: The linear seesaw mechanism provides a simple way to generate neutrino masses. In addition to Standard Model particles, it includes quasi-Dirac leptons as neutrino mass mediators, and a leptophilic scalar doublet seeding small neutrino masses. Here we review its associated physics, including restrictions from theory and phenomenology. The model yields potentially detectable μ-> e gamma rates as well as distinctive signatures in the production and decay of heavy neutrinos ( N-i) and the charged Higgs boson (H-+/-) arising from the second scalar doublet. We have found that production processes such as e(+) e(-) -> NN, e- gamma -> NH- and e(+) e(-) -> H (+) H- followed by the decay chain H-+/--> l(+/-) (i) N, N -> l`(+/-) (j) W (-/+) leads to striking lepton number violation signatures at high energies which may probe the Majorana nature of neutrinos.
|
|
|
|
NOMAD Collaboration(Samoylov, O. et al), Cervera-Villanueva, A., Gomez-Cadenas, J. J., & Hernando, J. (2013). A precision measurement of charm dimuon production in neutrino interactions from the NOMAD experiment. Nucl. Phys. B, 876(2), 339–375.
Abstract: We present our new measurement of the cross-section for charm dimuon production in neutrino iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15 344 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample – about 9 x 10(6) events after all analysis cuts – and the high resolution NOMAD detector to constrain the total systematic uncertainty on the ratio of charm dimuon to inclusive Charged Current (CC) cross-sections to similar to 2%. We also perform a fit to the NOMAD data to extract the charm production parameters and the strange quark sea content of the nucleon within the NLO QCD approximation. We obtain a value of m(c)(m(c)) = 1.159 +/- 0.075 GeV/c(2) for the running mass of the charm quark in the (MS) over bar scheme and a strange quark sea suppression factor of kappa(s) = 0.591 +/- 0.019 at Q(2) = 20 GeV2/c(2).
|
|
|
|
Barreiros, D. M., Joaquim, F. R., Srivastava, R., & Valle, J. W. F. (2021). Minimal scoto-seesaw mechanism with spontaneous CP violation. J. High Energy Phys., 04(4), 249–21pp.
Abstract: We propose simple scoto-seesaw models to account for dark matter and neutrino masses with spontaneous CP violation. This is achieved with a single horizontal Z8 discrete symmetry, broken to a residual Z2 subgroup responsible for stabilizing dark matter. CP is broken spontaneously via the complex vacuum expectation value of a scalar singlet, inducing leptonic CP-violating effects. We find that the imposed Z8 symmetry pushes the values of the Dirac CP phase and the lightest neutrino mass to ranges already probed by ongoing experiments, so that normal-ordered neutrino masses can be cornered by cosmological observations and neutrinoless double beta decay experiments.
|
|
|
|
Barenboim, G., & Park, W. I. (2017). Lepton number asymmetries and the lower bound on the reheating temperature. J. Cosmol. Astropart. Phys., 12(12), 037–13pp.
Abstract: We show that the reheating temperature of a matter-domination era in the early universe can be pushed down to the neutrino decoupling temperature at around 2 MeV if the reheating takes place through non-hadronic decays of the dominant matter and neutrino-antineutrino asymmetries are still large enough, vertical bar L vertical bar greater than or similar to O(10(-2)) (depending on the neutrino flavor) at the end of reheating.
|
|
