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Campos, F., Eboli, O. J. P., Magro, M. B., Porod, W., Restrepo, D., Das, S. P., et al. (2012). Probing neutralino properties in minimal supergravity with bilinear R-parity violation. Phys. Rev. D, 86(7), 075001–8pp.
Abstract: Supersymmetric models with bilinear R-parity violation can account for the observed neutrino masses and mixing parameters indicated by neutrino oscillation data. We consider minimal supergravity versions of bilinear R-parity violation where the lightest supersymmetric particle is a neutralino. This is unstable, with a large enough decay length to be detected at the CERN Large Hadron Collider. We analyze the Large Hadron Collider potential to determine the lightest supersymmetric particle properties, such as mass, lifetime and branching ratios, and discuss their relation to neutrino properties.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2012). Study of X (3915) -> J/psi omega in two-photon collisions. Phys. Rev. D, 86(7), 072002–10pp.
Abstract: We study the process gamma gamma -> J/psi omega using a data sample of 519.2 fb(-1) recorded by the BABAR detector at SLAC at the PEP-II asymmetric-energy e(+)e(-) collider at center-of-mass energies near the gamma(nS) (n = 2, 3, 4) resonances. We confirm the existence of the charmoniumlike resonance X (3915) decaying to J/psi omega with a significance of 7.6 standard deviations, including systematic uncertainties, and measure its mass (3919.4 +/- 2.2 +/- 1.6) MeV/c(2) and width (13 +/- 6 +/- 3) MeV, where the first uncertainty is statistical and the second systematic. A spin-parity analysis supports the assignment J(P) = 0(+) and therefore the identification of the signal as due to the chi(c0)(2P) resonance. In this hypothesis we determine the product between the two-photon width and the final state branching fraction to be (52 +/- 10 +/- 3) eV.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Improved limits on B-0 decays to invisible final states and to nu nubar gamma. Phys. Rev. D, 86(5), 051105–8pp.
Abstract: We establish improved upper limits on branching fractions for B-0 decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for final states where the only visible product is a photon. Within the Standard Model, these decays have branching fractions that are below the current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions for these channels. Using 471 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance by the BABAR experiment at the PEP-II e(+)e(-) storage ring at the SLAC National Accelerator Laboratory, we establish upper limits at the 90% confidence level of 2.4 x 10(-5) for the branching fraction of B-0 -> invisible and 1.7 x 10(-5) for the branching fraction of B-0 -> invisible + gamma.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Exclusive measurements of b -> s gamma transition rate and photon energy spectrum. Phys. Rev. D, 86(5), 052012–16pp.
Abstract: We use 429 fb(-1) of e(+)e(-) collision data collected at the Gamma(4S) resonance with the BABAR detector to measure the radiative transition rate of b -> s gamma with a sum of 38 exclusive final states. The inclusive branching fraction with a minimum photon energy of 1.9 GeV is found to be B((B) over bar -> X-s gamma) = (3.29 +/- 0.19 +/- 0.48) x 10(-4) where the first uncertainty is statistical and the second is systematic. We also measure the first and second moments of the photon energy spectrum and extract the best-fit values for the heavy-quark parameters, m(b) and mu(2)(pi), in the kinetic and shape function models.
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SciBooNE and MiniBooNE collaborations(Cheng, G. et al), Catala-Perez, J., Gomez-Cadenas, J. J., & Sorel, M. (2012). Dual baseline search for muon antineutrino disappearance at 0.1 eV(2) < Delta m(2) < 100 eV(2). Phys. Rev. D, 86(5), 052009–14pp.
Abstract: The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of (nu) over bar (mu) at Fermilab's Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their data sets serves to partially constrain some of the flux and cross section uncertainties. Uncertainties in the nu(mu) background were constrained by neutrino flux and cross section measurements performed in both detectors. A likelihood ratio method was used to set a 90% confidence level upper limit on (nu) over bar (mu) disappearance that dramatically improves upon prior limits in the Delta m(2) = 0.1-100 eV(2) region.
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