Blennow, M., Dasgupta, B., Fernandez-Martinez, E., & Rius, N. (2011). Aidnogenesis via leptogenesis and dark sphalerons. J. High Energy Phys., 03(3), 014–14pp.
Abstract: We discuss aidnogenesis,(1) i.e. the generation of a dark matter asymmetry, via new sphaleron processes associated to an extra non-abelian gauge symmetry common to both the visible and the dark sectors. Such a theory can naturally produce an abundance of asymmetric dark matter which is of the same size as the lepton and baryon asymmetries, as suggested by the similar sizes of the observed baryonic and dark matter energy content, and provide a definite prediction for the mass of the dark matter particle. We discuss in detail a minimal realization in which the Standard Model is only extended by dark matter fermions which form “dark baryons” through an SU(3) interaction, and a (broken) horizontal symmetry that induces the new sphalerons. The dark matter mass is predicted to be similar to 6GeV, close to the region favored by DAMA and CoGeNT. Furthermore, a remnant of the horizontal symmetry should be broken at a lower scale and can also explain the Tevatron dimuon anomaly.
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Bustamante, M., Gago, A. M., & Jones Perez, J. (2011). SUSY renormalization group effects in ultra high energy neutrinos. J. High Energy Phys., 05(5), 133–26pp.
Abstract: We have explored the question of whether the renormalization group running of the neutrino mixing parameters in the Minimal Supersymmetric Standard Model is detectable with ultra-high energy neutrinos from active galactic nuclei (AGN). We use as observables the ratios of neutrino fluxes produced at the AGN, focusing on four different neutrino production models: (Phi(0)(v epsilon+(v) over bar epsilon) : Phi(0)(v mu+(v) over bar mu) : Phi(0)(v tau+(v) over bar tau)) = (1 : 2 : 0), (0 : 1 : 0), (1 : 0 : 0), and (1 : 1 : 0). The prospects for observing deviations experimentally are taken into consideration, and we find out that it is necessary to impose a cut-off on the transferred momentum of Q(2) >= 10(7) GeV(2). However, this condition, together with the expected low value of the diffuse AGN neutrino flux, yields a negligible event rate at a km-scale. Cerenkov detector such as IceCube.
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Boucenna, M. S., Hirsch, M., Morisi, S., Peinado, E., Taoso, M., & Valle, J. W. F. (2011). Phenomenology of dark matter from A_4 flavor symmetry. J. High Energy Phys., 05(5), 037–20pp.
Abstract: We investigate a model in which Dark Matter is stabilized by means of a Z(2) parity that results from the same non-abelian discrete flavor symmetry which accounts for the observed patter of neutrino mixing. In our A(4) example the standard model is extended by three extra Higgs doublets and the Z(2) parity emerges as a remnant of the spontaneous breaking of A(4) after electroweak symmetry breaking. We perform an analysis of the parameter space of the model consistent with electroweak precision tests, collider searches and perturbativity. We determine the regions compatible with the observed relic dark matter density and we present prospects for detection in direct as well as indirect Dark Matter search experiments.
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Gomez-Cadenas, J. J., Martin-Albo, J., Sorel, M., Ferrario, P., Monrabal, F., Muñoz, J., et al. (2011). Sense and sensitivity of double beta decay experiments. J. Cosmol. Astropart. Phys., 06(6), 007–30pp.
Abstract: The search for neutrinoless double beta decay is a very active field in which the number of proposals for next-generation experiments has proliferated. In this paper we attempt to address both the sense and the sensitivity of such proposals. Sensitivity comes first, by means of proposing a simple and unambiguous statistical recipe to derive the sensitivity to a putative Majorana neutrino mass, m(beta beta). In order to make sense of how the different experimental approaches compare, we apply this recipe to a selection of proposals, comparing the resulting sensitivities. We also propose a “physics-motivated range” (PMR) of the nuclear matrix elements as a unifying criterium between the different nuclear models. The expected performance of the proposals is parametrized in terms of only four numbers: energy resolution, background rate (per unit time, isotope mass and energy), detection efficiency, and beta beta isotope mass. For each proposal, both a reference and an optimistic scenario for the experimental performance are studied. In the reference scenario we find that all the proposals will be able to partially explore the degenerate spectrum, without fully covering it, although four of them (KamLAND-Zen, CUORE, NEXT and EXO) will approach the 50 meV boundary. In the optimistic scenario, we find that CUORE and the xenon-based proposals (KamLAND-Zen, EXO and NEXT) will explore a significant fraction of the inverse hierarchy, with NEXT covering it almost fully. For the long term future, we argue that Xe-136-based experiments may provide the best case for a 1-ton scale experiment, given the potentially very low backgrounds achievable and the expected scalability to large isotope masses.
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Villaescusa-Navarro, F., Miralda-Escude, J., Pena-Garay, C., & Quilis, V. (2011). Neutrino halos in clusters of galaxies and their weak lensing signature. J. Cosmol. Astropart. Phys., 06(6), 027–14pp.
Abstract: We study whether non-linear gravitational effects of relic neutrinos on the development of clustering and large-scale structure may be observable by weak gravitational lensing. We compute the density profile of relic massive neutrinos in a spherical model of a cluster of galaxies, for several neutrino mass schemes and cluster masses. Relic neutrinos add a small perturbation to the mass profile, making it more extended in the outer parts. In principle, this non-linear neutrino perturbation is detectable in an all-sky weak lensing survey such as EUCLID by averaging the shear profile of a large fraction of the visible massive clusters in the universe, or from its signature in the general weak lensing power spectrum or its cross-spectrum with galaxies. However, correctly modeling the distribution of mass in baryons and cold dark matter and suppressing any systematic errors to the accuracy required for detecting this neutrino perturbation is severely challenging.
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