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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., 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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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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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Study of the baryonic B decay B- -> Sigma(++)(c) (p)over-bar pi(-)pi(-). Phys. Rev. D, 86(9), 091102–8pp.
Abstract: We report the measurement of the baryonic B decay B- -> Sigma(++)(c)(p) over bar pi(-)pi(-). Using a data sample of 467 x 10(6) B (B) over bar pairs collected with the BABAR detector at the PEP-II storage ring at SLAC, the measured branching fraction is (2.98 +/- 0.16((stat)) +/- 0.15((syst)) +/- 0.77((Ac))) x 10(-4), where the last error is due to the uncertainty in B(A(c)(+) -> pK(-)pi(+)). The data suggest the existence of resonant subchannels B- -> A(c)(2595)(+) (p) over bar pi(-) and, possibly, B- -> Sigma(++)(c) (Delta) over bar (--)pi(-). We see unexplained structures in m(Sigma(++)(c)pi(-)pi(-)) at 3.25 GeV/c(2), 3.8 GeV/c(2), and 4.2 GeV/c(2).
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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). A search for t(t)over-bar resonances in lepton plus jets events with highly boosted top quarks collected in pp collisions at root s=7 TeV with the ATLAS detector. J. High Energy Phys., 09(9), 041–45pp.
Abstract: A search for resonant production of high-mass top-quark pairs is performed on 2.05 fb(-1) of proton-proton collisions at root s = 7 TeV collected in 2011 with the ATLAS experiment at the Large Hadron Collider. This analysis of the lepton+jets final state is specifically designed for the particular topology that arises from the decay of highly boosted top quarks. The observed t (t) over bar invariant mass spectrum is found to be compatible with the Standard Model prediction and 95% credibility level upper limits are derived on the t (t) over bar production rate through new massive states. An upper limit of 0.7 pb is set on the production cross section times branching fraction of a narrow 1 TeV resonance. A Kaluza-Klein gluon with a mass smaller than 1.5 TeV is excluded.
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