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Borexino Collaboration(Bellini, G. et al), & Pena-Garay, C. (2012). Absence of a day-night asymmetry in the Be-7 solar neutrino rate in Borexino. Phys. Lett. B, 707(1), 22–26.
Abstract: We report the result of a search for a day-night asymmetry in the Be-7 solar neutrino interaction rate in the Borexino detector at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The measured asymmetry is A(dn) = 0.001 +/- 0.012 (stat) +/- 0.007 (syst), in agreement with the prediction of MSW-LMA solution for neutrino oscillations. This result disfavors MSW oscillations with mixing parameters in the LOW region at more than 8.5 sigma. This region is, for the first time, strongly disfavored without the use of reactor anti-neutrino data and therefore the assumption of CPT symmetry. The result can also be used to constrain some neutrino oscillation scenarios involving new physics.
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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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Dijon, A. et al, Gadea, A., & Huyuk, T. (2012). Discovery of a new isomeric state in Ni-68: Evidence for a highly deformed proton intruder state. Phys. Rev. C, 85(3), 031301–5pp.
Abstract: We report on the observation of a new isomeric state in Ni-68. We suggest that the newly observed state at 168(1) keV above the first 2(+) state is a pi(2p-2h) 0(+) state across the major Z = 28 shell gap. Comparison with theoretical calculations indicates a pure proton intruder configuration and the deduced low-lying structure of this key nucleus suggests a possible shape coexistence scenario involving a highly deformed state.
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Liu, B. C., & Xie, J. J. (2012). The K- p -> eta Lambda reaction in an effective Lagrangian model. Phys. Rev. C, 85(3), 038201–4pp.
Abstract: We report on a theoretical study of the K- p -> eta Lambda reaction near threshold by using an effective Lagrangian approach. The role of s-channel Lambda(1670), t-channel K*, and u-channel proton pole diagrams are considered. We show that the total cross section data are well reproduced. However, only including the s-wave Lambda(1670) state and the background contribution from t and u channels is not enough to describe the bowl structures in the angular distribution of the K- p -> eta Lambda reaction, which indicates that there should be higher partial waves contributing to this reaction in some energy region. Indeed, if we considered the contributions from a D-03 resonance, we could describe the bowl structures; however, a rather small width (similar to 2 MeV) of this resonance would be needed.
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BABAR Collaboration(Lees, J. P. et al), Azzolini, V., Martinez-Vidal, F., & Oyanguren, A. (2012). Study of (B)over-bar -> X(u)l(v)over-bar decays in B(B)over-bar events tagged by a fully reconstructed B-meson decay and determination of vertical bar V-ub vertical bar. Phys. Rev. D, 86(3), 032004–23pp.
Abstract: We report measurements of partial branching fractions for inclusive charmless semileptonic B decays (B) over bar -> X(u)l (v) over bar and the determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element vertical bar V-ub vertical bar. The analysis is based on a sample of 467 x 10(6) Y(4S) -> B (B) over bar decays recorded with the BABAR detector at the PEP- II e(+)e(-) storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions Delta B in several restricted regions of phase space and determine the CKM element vertical bar V-ub vertical bar based on different QCD predictions. For decays with a charged lepton momentum p(l)* > 1.0 GeV in the B meson rest frame, we obtain Delta B = (1.80 +/- 0.13(stat) +/- 0.15(sys) +/- 0.02(theo)) x 10(-3) from a fit to the two-dimensional M-X – q(2) distribution. Here, M-X refers to the invariant mass of the final state hadron X and q(2) is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract vertical bar V-ub vertical bar = (4.33 +/- 0.24(exp) +/- 0.15(theo)) x 10(-3) as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for (B) over bar (0) and B- decays and derive a limit on the isospin breaking in (B) over bar -> X(u)l (v) over bar decays.
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