Bazzocchi, F., Cerdeño, D. G., Muñoz, C., & Valle, J. W. F. (2010). Calculable inverse-seesaw neutrino masses in supersymmetry. Phys. Rev. D, 81(5), 051701–5pp.
Abstract: We provide a scenario where naturally small and calculable neutrino masses arise from a supersymmetry-breaking renormalization-group-induced vacuum expectation value. The construction consists of an extended version of the next-to-minimal supersymmetric standard model and the mechanism is illustrated for a universal choice of the soft supersymmetry-breaking parameters. The lightest supersymmetric particle can be an isosinglet scalar neutrino state, potentially viable as WIMP dark matter through its Higgs new boson coupling. The scenario leads to a plethora of new phenomenological implications at accelerators including the Large Hadron Collider.
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BABAR Collaboration(Aubert, B. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Measurement of branching fractions of B decays to K-1(1270)pi and K-1(1400)pi and determination of the CKM angle alpha from B-0 -> a(1)(1260)(+/-)pi(-/+). Phys. Rev. D, 81(5), 052009–16pp.
Abstract: We report measurements of the branching fractions of neutral and charged B meson decays to final states containing a K-1(1270) or K-1(1400) meson and a charged pion. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, correspond to 454 x 10(6) B (B) over bar pairs produced in e(+)e(-) annihilation. We measure the branching fractions B(B-0 -> K-1(1270)(+)pi(-) + K-1(1400)(+)pi(-)) = 3.1(-0.7)(+0.8) x 10(-5) and B(B+ -> K-1(1270)(0)pi(+) + K1(1400)(0)pi(+)) = 2.9(-1.7)(+2.9) x 10(-5) (< 8.2 x 10(-5) at 90% confidence level), where the errors are statistical and systematic combined. The B-0 decay mode is observed with a significance of 7.5 sigma, while a significance of 3.2 sigma is obtained for the B+ decay mode. Based on these results, we estimate the weak phase alpha = (79 +/- 7 +/- 11)degrees from the time-dependent CP asymmetries in B-0 -> a(1)(1260)(+/-)pi(-/+) decays.
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BABAR Collaboration(Lees, J. P. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Measurement of the gamma gamma* -> eta c transition form factor. Phys. Rev. D, 81(5), 052010–18pp.
Abstract: We study the reaction e(+)e(-) -> e(+)e(-) eta(c), eta(c) -> KSK +/-pi(-/+) and obtain eta(c) mass and width values 2982.2 +/- 0.4 +/- 1.6 MeV/c(2) and 31.7 +/- 1.2 +/- 0.8 MeV, respectively. We find Gamma(eta(c) -> gamma gamma)B(eta(c) -> KK pi) = 0.374 +/- 0.009 +/- 0.031 keV, and measure the gamma gamma* -> eta(c) transition form factor in the momentum transfer range from 2 to 50 GeV2. The analysis is based on 469 fb(-1) of integrated luminosity collected at PEP-II with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV.
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Branz, T., Geng, L. S., & Oset, E. (2010). Two-photon and one-photon-one-vector meson decay widths of the f(0)(1370), f(2)(1270), f(0)(1710), f(2)'(1525), and K-2*(1430). Phys. Rev. D, 81(5), 054037–10pp.
Abstract: We calculate the radiative decay widths, two-photon (gamma gamma) and one-photon-one-vector meson (V gamma), of the dynamically generated resonances from vector-meson -vector-meson interaction in a unitary approach based on the hidden-gauge Lagrangians. In the present paper we consider the following dynamically generated resonances: f(0)(1370), f(0)(1710), f(2)(1270), f(2)'(1525) K-2*(1430), two strangeness 0 and isospin 1 states, and two strangeness 1 and isospin 1= 2 states. For the f(0)(1370) and f(2)(1270) we reproduce the previous results for the two-photon decay widths and further calculate their one-photon -one-vector decay widths. For the f(0)(1710) and f(2)'(1525) the calculated two-photon decay widths are found to be consistent with data. The rho 0 gamma, omega gamma and phi gamma decay widths of the f0(1370), f(2)'(1270) f(0)(1710), f(2)'(1525) are compared with the results predicted by other approaches. The K*(+)gamma and K*(0)gamma decay rates of the K-2*(1430) are also calculated and compared with the results obtained in the framework of the covariant oscillator quark model. The results for the two states with strangeness 0, isospin 1 and two states with strangeness 1, isospin 1/ 2 are predictions that need to be tested by future experiments.
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Esteban-Pretel, A., Tomas, R., & Valle, J. W. F. (2010). Interplay between collective effects and nonstandard interactions of supernova neutrinos. Phys. Rev. D, 81(6), 063003–16pp.
Abstract: We consider the effect of nonstandard neutrino interactions (NSI, for short) on the propagation of neutrinos through the supernova (SN) envelope within a three-neutrino framework and taking into account the presence of a neutrino background. We find that for given NSI parameters, with strength generically denoted by epsilon(ij), neutrino evolution exhibits a significant time dependence. For vertical bar epsilon(tau tau)vertical bar greater than or similar to 10(-3) the neutrino survival probability may become sensitive to the V-23 octant and the sign of epsilon(tau tau). In particular, if epsilon(tau tau) greater than or similar to 10(-2) an internal I-resonance may arise independently of the matter density. For typical values found in SN simulations this takes place in the same dense-neutrino region above the neutrinosphere where collective effects occur, in particular, during the synchronization regime. This resonance may lead to an exchange of the neutrino fluxes entering the bipolar regime. The main consequences are (i) bipolar conversion taking place for normal neutrino mass hierarchy and (ii) a transformation of the flux of low-energy v(e), instead of the usual spectral swap.
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Agullo, I., Navarro-Salas, J., Olmo, G. J., & Parker, L. (2010). Revising the observable consequences of slow-roll inflation. Phys. Rev. D, 81(4), 043514–14pp.
Abstract: We study the generation of primordial perturbations in a (single-field) slow-roll inflationary Universe. In momentum space, these (Gaussian) perturbations are characterized by a zero mean and a nonzero variance Delta(2) (k, t). However, in position space the variance diverges in the ultraviolet. The requirement of a finite variance in position space forces one to regularize Delta(2) (k, t). This can (and should) be achieved by proper renormalization in an expanding Universe in a unique way. This affects the predicted scalar and tensorial power spectra (evaluated when the modes acquire classical properties) for wavelengths that today are at observable scales. As a consequence, the imprint of slow-roll inflation on the cosmic microwave background anisotropies is significantly altered. We find a nontrivial change in the consistency condition that relates the tensor-to-scalar ratio r to the spectral indices. For instance, an exact scale-invariant tensorial power spectrum, n(t) = 0, is now compatible with a nonzero ratio r approximate to 0.12 +/- 0.06, which is forbidden by the standard prediction (r = -8n(t)). The influence of relic gravitational waves on the cosmic microwave background may soon come within the range of planned measurements, offering a nontrivial test of the new predictions.
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BABAR Collaboration(Aubert, B. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Measurement and interpretation of moments in inclusive semileptonic decays (B)over-bar -> Xcl(nu)over-bar. Phys. Rev. D, 81(3), 032003–25pp.
Abstract: We present results for the moments of observed spectra in inclusive semileptonic B-meson decays to charm hadrons (B) over bar -> X(c)l(-)(nu) over bar. Moments of the hadronic-mass and the combined mass-and-energy spectra for different minimum electron or muon momenta between 0.8 and 1: 9 GeV/c are obtained from a sample of 232 X 10(6) Gamma(4S) -> B (B) over bar events, collected with the BABAR detector at the PEP-II asymmetric-energy B-meson factory at SLAC. We also present a reevaluation of the moments of electron-energy spectra and partial decay fractions B((B) over bar -> X(c)e(-)(nu) over bar) for minimum electron momenta between 0.6 and 1: 5 GeV/c based on a sample of 51 X 10(6) Gamma(4S) -> B (B) over bar events. The measurements are used for the extraction of the total decay fraction, the Cabibbo-Kobayashi-Maskawa (CKM) matrix element vertical bar V-cb vertical bar, the quark masses m(b) and m(c), and four heavy-quark QCD parameters in the framework of a Heavy-Quark Expansion (HQE). We find B((B) over bar -> X(c)l(-)(nu) over bar = (10.64 +/- 0.17 +/- 0.06)% and vertical bar V-cb vertical bar = (42.05 +/- 0.45 +/- 0.70) X 10(-3).
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SciBooNE Collaboration(Kurimoto, Y. et al), Catala-Perez, J., Gomez-Cadenas, J. J., & Sorel, M. (2010). Measurement of inclusive neutral current pi(0) production on carbon in a few-GeV neutrino beam. Phys. Rev. D, 81(3), 033004–18pp.
Abstract: The SciBooNE Collaboration reports inclusive neutral current neutral pion production by a muon neutrino beam on a polystyrene target (C8H8). We obtain (7.7 +/- 0.5(stat) +/- 0.5(sys)) X 10(-2) as the ratio of the neutral current neutral pion production to total charged current cross section; the mean energy of neutrinos producing detected neutral pions is 1.1 GeV. The result agrees with the Rein-Sehgal model implemented in our neutrino interaction simulation program with nuclear effects. The spectrum shape of the pi(0) momentum and angle agree with the model. We also measure the ratio of the neutral current coherent pion production to total charged current cross section to be (0.7 +/- 0.4) X 10(-2).
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Aguilar, A. C., & Papavassiliou, J. (2010). Gluon mass generation without seagull divergences. Phys. Rev. D, 81(3), 034003–19pp.
Abstract: Dynamical gluon mass generation has been traditionally plagued with seagull divergences, and all regularization procedures proposed over the years yield finite but scheme-dependent gluon masses. In this work we show how such divergences can be eliminated completely by virtue of a characteristic identity, valid in dimensional regularization. The ability to trigger the aforementioned identity hinges crucially on the particular Ansatz employed for the three-gluon vertex entering into the Schwinger-Dyson equation governing the gluon propagator. The use of the appropriate three-gluon vertex brings about an additional advantage: one obtains two separate (but coupled) integral equations, one for the effective charge and one for the gluon mass. This system of integral equations has a unique solution, which unambiguously determines these two quantities. Most notably, the effective charge freezes in the infrared, and the gluon mass displays power-law running in the ultraviolet, in agreement with earlier considerations.
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Mathieu, V., & Vento, V. (2010). Pseudoscalar glueball and eta-eta ' mixing. Phys. Rev. D, 81(3), 034004–12pp.
Abstract: We have performed a dynamical analysis of the mixing in the pseudoscalar channel with the goal of understanding the existence and behavior of the pseudoscalar glueball. Our philosophy has not been to predict precise values of the glueball mass but to exploit an adequate effective theory to the point of breaking and to analyze which kind of mechanisms restore compatibility with data. Our study has led to analytical solutions which allow a clear understanding of the phenomena. The outcome of our calculation leads to a large mass glueball M-Theta > 2000 MeV, to a large glue content of the eta ', and to mixing angles in agreement with previous numerical studies.
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