Leptoquark effects on ντ propagation in the Earth

The detection of a ντ flux in a neutrino telescope would provide a way to measure the cosmic flux without the background of the atmospheric νμ’s. Given that effects of new physics could alter the flux arriving at the detector, in this work we consider, as a particular scenario, the effects of leptoquarks on the propagation in the Earth of tau neutrinos. We calculate their contribution to the neutrino–nucleon interaction and their effect on the transport. We show the resulting ντ flux and compare it with the νμ flux after through the planet. Finally, we obtain the 90 % C.L. region (Sensitivity Region) where neutrino telescopes will be sensible to the leptoquark effects.Fil: Reynoso, Matias Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Mar del Plata. Instituto de Investigaciones Fisicas de Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Romero, Ismael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Mar del Plata. Instituto de Investigaciones Fisicas de Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Sampayo, Oscar Alfredo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Mar del Plata. Instituto de Investigaciones Fisicas de Mar del Plata; Argentin

Photons coming from an opaque obstacle as a manifestation of heavy neutrino decays

Within the framework of physics beyond the standard model, we study the possibility that mesons produced in the atmosphere by the cosmic-ray flux decay to heavy Majorana neutrinos and the latter, in turn, decay mostly to photons in the low-mass region. We study the photon flux produced by sterile Majorana neutrinos (N) decaying after passing through a massive and opaque object such as a mountain. To model the production of N's in the atmosphere and their decay to photons, we consider the interaction between the Majorana neutrinos and the standard matter as modeled by an effective theory. We then calculate the heavy neutrino flux originated by the decay of mesons in the atmosphere. The surviving photon flux, originated by N decays, is calculated using transport equations that include the effects of Majorana neutrino production and decay.Fil: Reynoso, Matias Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Romero, Ismael. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Sampayo, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin

Angular and polarization trails from effective interactions of Majorana neutrinos at the LHeC

We study the possibility of the LHeC facility to disentangle different new physics contributionsto the production of heavy sterile Majorana neutrinos in the lepton number violating channele−p → l+j + 3jets (lj ≡ e, µ). This is done investigating the angular and polarization trails ofeffective operators with distinct Dirac-Lorentz structure contributing to the Majorana neutrinoproduction, which parameterize new physics from a higher energy scale. We study an asymmetryin the angular distribution of the final anti-lepton and the initial electron polarization effect on thenumber of signal events produced by the vectorial and scalar effective interactions, finding bothanalyses could well separate their contributions.Fil: Duarte, Lucia. UNIVERSIDAD DE LA REPUBLICA (UDELAR);Fil: Zapata, Gabriel Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Sampayo, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin

Majorana neutrinos production at LHeC in an effective approach

We investigate the possibility of detecting Majorana neutrinos at the Large Hadron-electron Collider (LHeC), an electron-proton collision mode at CERN. We study the $l_j^{+} + 3 jets$ ($l_j\equiv e ,\mu ,\tau$) final states which are, due to leptonic number violation, a clear signature for intermediate Majorana neutrino contributions. Such signals are not possible if the heavy neutrinos have Dirac nature. The interactions between Majorana neutrinos and the Standard Model (SM) particles are obtained from an effective lagrangian approach. We present our results for the total cross section as a function of the neutrino mass, the effective couplings and the new physics scale. We also show the discovery region as a function of the Majorana neutrino mass and the effective couplings. Our results show that the LHeC may be able to discover Majorana neutrinos with masses lower than $700$ GeV and $1300$ GeV for electron beams settings of $E_e=50$ GeV and $E_e=150$ GeV, respectively.Comment: 15 pages, 11 pdf figures. arXiv admin note: text overlap with arXiv:1110.095

Oscillation tomografy study of Earth's composition and density with atmospheric neutrinos

Knowledge of the composition of the Earth's interior is highly relevant to many geophysical and geochemical problems. Neutrino oscillations are modified in a non-trivial way by the matter effects and can provide valuable and unique information not only on the density but also on the chemical and isotopic composition of the deep regions of the planet. In this paper, we re-examine the possibility of performing an oscillation tomography of the Earth with atmospheric neutrinos and antineutrinos to obtain information on the composition and density of the outer core and the mantle, complementary to that obtained by geophysical methods. Particular attention is paid to the D$^{\prime \prime}$ layer just above the core-mantle boundary and to the water (hydrogen) content in the mantle transition zone. Our analysis is based on a Monte-Carlo simulation of the energy and azimuthal angle distribution of $\mu$-like events generated by neutrinos. Taking as reference a model of the Earth consisting of 55 concentric layers with constant densities determined from the PREM, we evaluate the effect on the number of events due to changes in the composition and density of the outer core and the mantle. To examine the capacity of a detector like ORCA to resolve such variations, we construct regions in planes of two of these quantities where the statistical significance of the discrepancies between the reference and the modified Earth are less than $1\sigma$. The variations are implemented in such a way that the constraint imposed by both the total mass of the Earth and its moment of inertia are verified.Comment: Already published in the European Physical Journal

Precession of neutrino-cooled accretion disks in gamma-ray burst engines

Aims. We study the precession of accretion disks in the context of gamma-ray burst inner engines. Methods. With an accretion disk model that allows for neutrino cooling, we evaluate the possible periods of disk precession and nutation due to the Lense-Thirring effect. Results. Assuming jet ejection perpendicular to the disk midplane and a typical intrinsic time dependence for the burst, we find possible gamma-ray light curves with a temporal microstructure similar to what is observed in some subsamples. Conclusions. We conclude that the precession and nutation of a neutrino-cooled accretion disk in the burst engine might be responsible for some events, especially those with a slow rise and a fast decay.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí

Earth tomography with atmospheric neutrino oscillations

The study of the flux of atmospheric neutrino crossing the Earth can provide useful information not only on the matter density of the different layers that make up the planet but also on their chemical composition. The key phenomenon that makes this possible is flavor oscillations and their dependence on the electron density along the neutrino baseline. To extract the relevant information, we simulate the energy and azimuth angle distribution of events produced in a generic neutrino telescope by atmospheric neutrinos passing through the deepest parts of the Earth. Changes in the densities of the outer core and the mantle are implemented by varying the location of the boundary between these layers so that the restrictions on the mass of and the moment of inertia of the Earth are both satisfied. This allows us to examine the effect of simultaneous changes in composition and density of the outer core, unlikely other works on the subject, where only one of these quantities was varied.Fil: D'Olivo, Juan Carlos. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Herrera Lara, José Arnulfo. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Romero, Ismael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Sampayo, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Zapata, Gabriel Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin

Manifestaciones de subestructura en interacciones electrodébiles

Facultad de Ciencias Exacta

Manifestaciones de subestructura en interacciones electrodébiles

Facultad de Ciencias Exacta

Neutrinos de alta energía y el interior de la tierra

Los estudios sobre la distribución de masa de la tierra están basados en datos sismológicos, la interpretación de los cuales es dependiente de hipótesis acerca del estado de la materia en el interior de la tierra. Por otro lado la dispersión de neutrinos atmosféricos con los nucleones que forman la materia del planeta puede convertirse en una fuente de información alternativa y completamente independiente de hipótesis geofísicas. En este trabajo investigamos el problema con la aplicación de un observable que ha probado ser débilmente dependiente de incertezas en el flujo inicial y de la sistemática experimental. Se utilizan como vínculos la masa de la Tierra y su momento de inercia. El trabajo está basado en la detección de neutrinos a realizarse por telescopios tipo IceCube.Fil: Romero, Ismael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Sampayo, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin