Reig, M., Valle, J. W. F., & Vaquera-Araujo, C. A. (2016). Realistic SU(3)(c) x SU(3)(L) x U(1)(X) model with a type II Dirac neutrino seesaw mechanism. Phys. Rev. D, 94(3), 033012–4pp.
Abstract: Here we propose a realistic SU(3)(c) circle times SU(3)(L) circle times U(1)(X) electroweak gauge model with enlarged Higgs sector. The scheme allows for the natural implementation of a type II seesaw mechanism for Dirac neutrinos, while charged lepton and quark masses are reproduced in a natural way thanks to the presence of new scalars. The new SU(3)(c) circle times SU(3)(L) circle times U(1)(X) energy scale characterizing neutrino mass generation could be accessible to the current LHC experiments.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., Ruiz Valls, P., et al. (2016). Measurement of CP Violation in B-0 -> D+D- Decays. Phys. Rev. Lett., 117(26), 261801–10pp.
Abstract: The CP violation observables S and C in the decay channel B-0 -> D+D- are determined from a sample of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb(-1). The observable S describes CP violation in the interference between mixing and the decay amplitude, and C parametrizes direct CP violation in the decay. The following values are obtained from a flavor-tagged, decay-time-dependent analysis: S = -0.54(-0.16)(+0.17) (stat) +/- 0.05(syst) ,C=0.26(-0.17)(+0.18) (stat) +/- 0.02(syst). These values provide evidence for CP violation at a significance level of 4.0 standard deviations. The phase shift due to higher-order standard model corrections is constrained to a small value of Delta phi = -0.16(-0.21)(+0.19) rad.
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Donini, A., Hernandez, P., Pena, C., & Romero-Lopez, F. (2016). Nonleptonic kaon decays at large N-c. Phys. Rev. D, 94(11), 114511–6pp.
Abstract: We study the scaling with the number of colors, N-c, of the weak amplitudes mediating kaon mixing and decay. We evaluate the amplitudes of the two relevant current-current operators on the lattice for N-c = 3-7. We conclude that the subleading 1/N-c corrections in B-k, are small, but those in the K -> pi pi amplitudes are large and fully anticoirelated in the I = 0, 2 isospin channels. We briefly comment on the implications for the Delta I = 1/2 rule.
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Pragati, Deo, A. Y., Podolyak, Z., Walker, P. M., Algora, A., Rubio, B., et al. (2016). Decay of the N=126, Fr-213 nucleus. Phys. Rev. C, 94(6), 064316–8pp.
Abstract: gamma rays following the EC/beta(+) and alpha decay of the N = 126, Fr-213 nucleus have been observed at the CERN isotope separator on-line (ISOLDE) facility with the help of gamma-ray and conversion-electron spectroscopy. These gamma rays establish several hitherto unknown excited states in Rn-213. Also, five new a-decay branches from the Fr-213 ground state have been discovered. Shell model calculations have been performed to understand the newly observed states in Rn-213.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2016). Measurement of the b(b)over-bar dijet cross section in pp collisions at root s=7 TeV with the ATLAS detector. Eur. Phys. J. C, 76(12), 670–24pp.
Abstract: The dijet production cross section for jets containing a b-hadron (b-jets) has been measured in protonproton collisions with a centre-of-mass energy of root s = 7 TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of 4.2 fb(-1). The cross section is measured for events with two identified b-jets with a transverse momentum pT > 20 GeV and a minimum separation in the eta-phi plane of Delta R = 0.4. At least one of the jets in the event is required to have p(T) > 270 GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the b-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization.
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