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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2012). Branching fraction of tau(-) -> pi(-KsKs0)-K-0(pi(0))nu(tau) decays. Phys. Rev. D, 86(9), 092013–9pp.
Abstract: We present a study of tau(-) -> pi(-KsKs0)-K-0(pi(0))nu(tau) and tau(-) -> (K-KsKs0)-K-0(pi(0))nu(tau) decays using a data set of 430 million tau lepton pairs, corresponding to an integrated luminosity of 468 fb(-1), collected with the BABAR detector at the PEP-II asymmetric energy e(+)e(-) storage rings. We measure branching fractions of (2.31 +/- 0.04 +/- 0.08) x 10(-4) and (1.60 +/- 0.20 +/- 0.22) x 10(-5) for the tau(-) -> pi(-KsKs0)-K-0 nu(tau) and tau(-) -> pi(-KsKs0)-K-0 pi(0)nu(tau) decays, respectively. We find no evidence for tau(-) -> (K-KsKs0)-K-0 nu(tau) and tau(-) -> (K-KsKs0)-K-0 pi(0)nu(tau) decays and place upper limits on the branching fractions of 6.3 x 10(-7) and 4.0 x 10(-7) at the 90% confidence level.
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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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Peinado, E., & Vicente, A. (2012). Neutrino masses from R-parity violation with a Z(3) symmetry. Phys. Rev. D, 86(9), 093024–9pp.
Abstract: We consider a supersymmetric model where the neutrino mass matrix arises from bilinear and trilinear R-parity violation, both restricted by a Z(3) flavor symmetry. Assuming flavor-blind soft supersymmetry breaking conditions, corrected at low energies due to running effects, we obtain a neutrino mass matrix in agreement with oscillation data. In particular, a large theta(13) angle can be easily accommodated. We also find a correlation between the reactor and atmospheric mixing angles. This leads in some scenarios to a clear deviation from theta(23) = pi/4. The lightest supersymmetric particle decay, dominated by the trilinear couplings, provides a direct way to test the model at colliders.
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ATLAS Collaboration(Aad, G. et al), Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Ferrer, A., Fiorini, L., et al. (2012). Search for Magnetic Monopoles in root s=7 TeV pp Collisions with the ATLAS Detector. Phys. Rev. Lett., 109(26), 261803–18pp.
Abstract: This Letter presents a search for magnetic monopoles with the ATLAS detector at the CERN Large Hadron Collider using an integrated luminosity of 2.0 fb(-1) of pp collisions recorded at a center-of-mass energy root s = 7 TeV. No event is found in the signal region, leading to an upper limit on the production cross section at 95% confidence level of 1.6/epsilon fb for Dirac magnetic monopoles with the minimum unit magnetic charge and with mass between 200 GeV and 1500 GeV, where epsilon is the monopole reconstruction efficiency. The efficiency epsilon is high and uniform in the fiducial region given by pseudorapidity vertical bar eta vertical bar < 1: 37 and transverse kinetic energy 600-700<E-kin sin theta< 1400 GeV. The minimum value of 700 GeV is for monopoles of mass 200 GeV, whereas the minimum value of 600 GeV is applicable for higher mass monopoles. Therefore, the upper limit on the production cross section at 95% confidence level is 2 fb in this fiducial region. Assuming the kinematic distributions from Drell-Yan pair production of spin-1= 2 Dirac magnetic monopoles, the efficiency is in the range 1%-10%, leading to an upper limit on the cross section at 95% confidence level that varies from 145 fb to 16 fb for monopoles with mass between 200 GeV and 1200 GeV. This limit is weaker than the fiducial limit because most of these monopoles lie outside the fiducial region.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Measurement of B (B -> Xs gamma), the B -> Xs gamma photon energy spectrum, and the direct CP asymmetry in B -> Xs+d gamma decays. Phys. Rev. D, 86(11), 112008–33pp.
Abstract: The photon spectrum in B -> X-s gamma decay, where X-s is any strange hadronic state, is studied using a data sample of (382.8 +/- 4.2) x 10(6) e(+)e(-) -> Upsilon(4S) -> B (B) over bar events collected by the BABAR experiment at the PEP-II collider. The spectrum is used to measure the branching fraction B(B -> X-s gamma) (3.21 +/- 0.15 +/- 0.29 +/- 0.08) x 10(-4) and the first, second, and third moments < E-gamma > = 2.267 +/- 0.019 +/- 0.032 +/- 0.003 GeV, <(E-gamma – < E-gamma >)(2)> = 0.0484 +/- 0.0053 +/- 0.0077 +/- 0.0005 GeV2, and <(E-gamma – < E-gamma)(3)> = -0.0048 +/- 0.0011 +/- 0.0011 +/- 0.0004 GeV3, for the range E-gamma > 1.8 GeV, where E-gamma is the photon energy in the B-meson rest frame. Results are also presented for narrower E-gamma ranges. In addition, the direct CP asymmetry A(CP)(B -> Xs+d gamma) is measured to be 0.057 +/- 0.063. The spectrum itself is also unfolded to the B-meson rest frame; that is the frame in which theoretical predictions for its shape are made.
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