Coloma, P., Donini, A., Fernandez-Martinez, E., & Hernandez, P. (2012). Precision on leptonic mixing parameters at future neutrino oscillation experiments. J. High Energy Phys., 06(6), 073–27pp.
Abstract: We perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters theta(13) and the CP phase, delta, assuming that theta(13) is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on delta on its true value. When matter effects are small, the largest error is found at the points where CP violation is maximal, and the smallest at the CP conserving points. The situation is different when matter effects are sizable. As a result of this effect, the comparison of the physics reach of different experiments on the basis of the CP discovery potential, as usually done, can be misleading. We have compared various proposed super-beam, beta-beam and neutrino factory setups on the basis of the relative precision of theta(13) and the error on delta. Neutrino factories, both high-energy or low-energy, outperform alternative beam technologies. An ultimate precision on theta(13) below 3% and an error on delta of <= 7 degrees at 1 sigma (1 d.o.f.) can be obtained at a neutrino factory.
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Calle Cordon, A., Pavon Valderrama, M., & Ruiz Arriola, E. (2012). Charge independence, charge symmetry breaking in the S-wave nucleon-nucleon interaction, and renormalization. Phys. Rev. C, 85(2), 024002–13pp.
Abstract: We explore the interplay between renormalization, charge independence and charge symmetry breaking (CIB and CSB) in S-wave nucleon-nucleon scattering. The renormalizability requirement generates universality functions, that is, correlations between the low-energy scattering observables in the neutron-neutron, neutron-proton, and proton-proton systems. The universality functions only depend on the (known) form of the nucleon-nucleon potential at long distances and, in particular, they do not require any assumptions about short-range CIB and CSB effects. In addition, the inclusion of Coulomb effects is trivial for the particular case of proton-proton scattering, allowing us to relate strong and Coulomb scattering observables. Within this approach, and using a one-boson-exchange potential, the previous correlations are shown to be phenomenologically satisfied without the need to introduce further parameters.
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ATLAS Collaboration(Aad, G. et al), Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Fassi, F., Ferrer, A., et al. (2012). Search for resonant top quark plus jet production in t(t)over-bar + jets events with the ATLAS detector in pp collisions at root s=7 TeV. Phys. Rev. D, 86(9), 091103–20pp.
Abstract: This paper presents a search for a new heavy particle produced in association with a top or antitop quark. Two models in which the new heavy particle is a color singlet or a color triplet are considered, decaying, respectively, to (t)over-barq or tq, leading to a resonance within the t(t)over-bar + jets signature. The full 2011 ATLAS pp collision data set from the LHC (4.7 fb(-1)) is used to search for t(t)over-bar events produced in association with jets, in which one of the W bosons from the top quarks decays leptonically and the other decays hadronically. The data are consistent with the Standard Model expectation, and a new particle with mass below 430 Gev for both W' boson and color triplet models is excluded at 95% confidence level, assuming unit right-handed coupling.
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Coutant, A., Fabbri, A., Parentani, R., Balbinot, R., & Anderson, P. R. (2012). Hawking radiation of massive modes and undulations. Phys. Rev. D, 86(6), 064022–17pp.
Abstract: We compute the analogue Hawking radiation for modes which possess a small wave vector perpendicular to the horizon. For low frequencies, the resulting mass term induces a total reflection. This reflection is accompanied by an extra mode mixing which occurs in the supersonic region, and which cancels out the infrared divergence of the near horizon spectrum. As a result, the amplitude of the undulation (0-frequency wave with macroscopic amplitude) emitted in white hole flows now saturates at the linear level, unlike what is found in the massless case. In addition, we point out that the mass introduces a new type of undulation which is produced in black hole flows, and which is well described in the hydrodynamical regime.
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Creminelli, P., Norena, J., Pena, M., & Simonovic, M. (2012). Khronon inflation. J. Cosmol. Astropart. Phys., 11(11), 032–16pp.
Abstract: We study the possibility that the approximate time shift symmetry during inflation is promoted to the full invariance under time reparametrization t -> (t) over tilde (t), or equivalently under field redefinition of the inflaton phi -> (phi) over tilde(phi). The symmetry allows only two operators at leading order in derivatives, so that all n-point functions of scalar perturbations are fixed in terms of the power spectrum normalization and the speed of sound. During inflation the decaying mode only decays as 1/a and this opens up the possibility to violate some of the consistency relations in the squeezed limit, although this violation is suppressed by the (small) breaking of the field reparametrization symmetry. In particular one can get terms in the 3-point function that are only suppressed by 1/k(L) in the squeezed limit k(L) -> 0 compared to the local shape.
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