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Galli, P., Ortin, T., Perz, J., & Shahbazi, C. S. (2011). Non-extremal black holes of N=2, d=4 supergravity. J. High Energy Phys., 07(7), 041.
Abstract: We propose a generic recipe for deforming extremal black holes into nonextremal black holes and we use it to find and study the static non-extremal black-hole solutions of several N = 2, d = 4 supergravity models (SL(2, R)/U(1), (CP) over bar (n) and STU with four charges). In all the cases considered, the non-extremal family of solutions smoothly interpolates between all the different extremal limits, supersymmetric and not supersymmetric. This fact can be used to explicitly find extremal non-supersymmetric solutions also in the cases in which the attractor mechanism does not completely fix the values of the scalars on the event horizon and they still depend on the boundary conditions at spatial infinity. We compare (supersymmetry) Bogomol'nyi bounds with extremality bounds, we find the first-order flow equations for the non-extremal solutions and the corresponding superpotential, which gives in the different extremal limits different superpotentials for extremal black holes. We also compute the entropies (areas) of the inner (Cauchy) and outer (event) horizons, finding in all cases that their product gives the square of the moduli-independent entropy of the extremal solution with the same electric and magnetic charges.
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Morisi, S., & Peinado, E. (2011). Admixture of quasi-Dirac and Majorana neutrinos with tri-bimaximal mixing. Phys. Lett. B, 701(4), 451–457.
Abstract: We propose a realization of the so-called bimodal/schizophrenic model proposed recently. We assume 54, the permutation group of four objects as flavor symmetry giving tri-bimaximal lepton mixing at leading order. In these models the second massive neutrino state is assumed quasi-Dirac and the remaining neutrinos are Majorana states. In the case of inverse mass hierarchy, the lower bound on the neutrinoless double beta decay parameter m(ee) is about two times that of the usual lower bound, within the range of sensitivity of the next generation of experiments.
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Bandos, I. A., de Azcarraga, J. A., & Meliveo, C. (2011). Extended supersymmetry in massless conformal higher spin theory. Nucl. Phys. B, 853(3), 760–776.
Abstract: We propose superfield equations in tensorial N-extended superspaces to describe the N = 2,4,8 supersymmetric generalizations of free conformal higher spin theories. These can be obtained by quantizing a superparticle model in N-extended tensorial superspace. The N-extended higher spin supermultiplets just contain scalar and 'spinor' fields in tensorial space so that, in contrast with the standard (super)space approach, no nontrivial generalizations of the Maxwell or Einstein equations to tensorial space appear when N > 2. For N = 4,8, the higher spin-tensorial components of the extended tensorial superfields are expressed through additional scalar and spinor fields in tensorial space which obey the same free higher spin equations, but that are axion-like in the sense that they possess Peccei-Quinn-like symmetries.
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Aparici, A., Herrero-Garcia, J., Rius, N., & Santamaria, A. (2011). Neutrino masses from new generations. J. High Energy Phys., 07(7), 122.
Abstract: We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the observed light neutrino mass hierarchy is not compatible with low energy universality bounds in this minimal scenario, but all present data can be accommodated with five generations and two right-handed neutrinos. Within this framework, we explore the parameter space regions which are currently allowed and could lead to observable effects in neutrinoless double beta decay, mu-e conversion in nuclei and μ-> e gamma experiments. We also discuss the detection prospects at LHC.
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CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2011). Measurement of the Forward-Backward Asymmetry in the B -> K-(*) mu(+)mu(-) Decay and First Observation of the B-s(0) -> phi mu(+)mu(-) Decay. Phys. Rev. Lett., 106(16), 161801–7pp.
Abstract: We reconstruct the rare decays B+ -> K+ mu(+)mu(-), B-0 -> K*(892)(0) mu(+)mu(-), and B-s(0) -> phi(1020) mu(+)mu(-) in a data sample corresponding to 4.4 fb(-1) collected in p (p) over bar collisions at root s = 1.96 TeV by the CDF II detector at the Tevatron Collider. Using 121 +/- 16 B+ -> K+ mu(+)mu(-) and 101 +/- 12 B-0 -> K-*0 mu(+)mu(-) decays we report the branching ratios. In addition, we report the differential branching ratio and the muon forwardbackward asymmetry in the B+ and B-0 decay modes, and the K-*0 longitudinal polarization fraction in the B-0 decay mode with respect to the squared dimuon mass. These are consistent with the predictions, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the B-s(0) -> phi mu(+)mu(-) decay and measure its branching ratio BR(B-s(0) -> phi mu(+)mu(-)) = [1.44 +/- 0.33 +/- 0.46] x 10(-6) using 27 +/- 6 signal events. This is currently the most rare B-s(0) decay observed.
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