Ren, X. L., Geng, L. S., Oset, E., & Meng, J. (2014). Test of h(1)(1830) made of K*K* with the eta(c) ->phi K*K* decay. Eur. Phys. J. A, 50(8), 133–5pp.
Abstract: We present a new reaction, complementary to from which an h (1) resonance with mass around 1830 MeV was reported from a BESIII experiment. The new reaction is , or . Using the information from the analysis of , we find that the invariant mass distribution for those two Iu decays exhibits a clear peak around 1830 MeV perfectly distinguishable from what one obtains with pure phase space. We suggest the implementation of these reactions to assert the existence of this elusive resonance which, by its nature as a vector-vector molecule with 0(-)(1(+-)) quantum numbers, only couples to the channel.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2014). Evidence for the decay X(3872) -> psi(2S)gamma. Nucl. Phys. B, 886, 665–680.
Abstract: Evidence for the decay mode X(3872) -> psi(2S)gamma in B+ -> X(3872)K+ decays is found with a significance of 4.4 standard deviations. The analysis is based on a data sample of proton proton collisions, corresponding to an integrated luminosity of 3 fb(-1), collected with the LHCb detector, at centre-of-mass energies of 7 and 8 TeV. The ratio of the branching fraction of the X(3872) -> psi(2S)gamma decay to that of the X(3872) -> J/psi gamma decay is measured to be B(X(3872) -> psi(2S)gamma)/B(X(3872) -> J/psi gamma) = 2.46 +/- 0.64 +/- 0.29, where the first uncertainty is statistical and the second is systematic. The measured value does not support a pure D (D) over bar* molecular interpretation of the X(3872) state.
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Gonzalez Felipe, R., & Serodio, H. (2014). Abelian realization of phenomenological two-zero neutrino textures. Nucl. Phys. B, 886, 75–92.
Abstract: In an attempt at explaining the observed neutrino mass-squared differences and leptonic mixing, lepton mass matrices with zero textures have been widely studied. In the weak basis where the charged lepton mass matrix is diagonal, various neutrino mass matrices with two zeros have been shown to be consistent with the current experimental data. Using the canonical and Smith normal form methods, we construct the minimal Abelian symmetry realizations of these phenomenological two-zero neutrino textures. The implementation of these symmetries in the context of the seesaw mechanism for Majorana neutrino masses is also discussed.
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Morales, A. I., Algora, A., Molina, F., & Rubio, B. (2014). Half-Life Systematics across the N=126 Shell Closure: Role of First-Forbidden Transitions in the beta Decay of Heavy Neutron-Rich Nuclei. Phys. Rev. Lett., 113(2), 022702–5pp.
Abstract: This Letter reports on a systematic study of beta-decay half-lives of neutron-rich nuclei around doubly magic Pb-208. The lifetimes of the 126-neutron shell isotone Pt-204 and the neighboring Ir200-202, Pt-203, Au-204 are presented together with other 19 half-lives measured during the “stopped beam” campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden beta strength reveal significant deviations for most of the nuclei with N < 126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during beta decay back to stability.
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Grodner, E. et al, Gadea, A., Algora, A., Agramunt, J., Domingo-Pardo, C., Molina, F., et al. (2014). Hindered Gamow-Teller Decay to the Odd-Odd N = Z Ga-62: Absence of Proton-Neutron T=0 Condensate in A=62. Phys. Rev. Lett., 113(9), 092501–5pp.
Abstract: Search for a new kind of superfluidity built on collective proton-neutron pairs with aligned spin is performed studying the Gamow-Teller decay of the T = 1, J(pi) = 0(+) ground state of Ge-62 into excited states of the odd-odd N = Z nucleus Ga-62. The experiment is performed at GSI Helmholtzzentrum fur Shwerionenforshung with the Ge-62 ions selected by the fragment separator and implanted in a stack of Si-strip detectors, surrounded by the RISING Ge array. A half-life of T-1/2 = 2 82.9(14) ms is measured for the Ge-62 ground state. Six excited states of Ga-62, populated below 2.5 MeV through Gamow-Teller transitions, are identified. Individual Gamow-Teller transition strengths agree well with theoretical predictions of the interacting shell model and the quasiparticle random phase approximation. The absence of any sizable low-lying Gamow-Teller strength in the reported beta-decay experiment supports the hypothesis of a negligible role of coherent T = 0 proton-neutron correlations in Ga-62.
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