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Alvarez-Ruso, L., Nieves, J., Ruiz Simo, I., Valverde, M., & Vicente Vacas, M. J. (2013). Charged kaon production by coherent scattering of neutrinos and antineutrinos on nuclei. Phys. Rev. C, 87(1), 015503–11pp.
Abstract: With the aim of achieving a better and more complete understanding of neutrino interactions with nuclear targets, the coherent production of charged kaons induced by neutrinos and antineutrinos is investigated in the energy range of some of the current neutrino experiments. We follow a microscopic approach which, at the nucleon level, incorporates the most important mechanisms allowed by the chiral-symmetry-breaking pattern of QCD. The distortion of the outgoing K ((K) over bar) is taken into account by solving the Klein-Gordon equation with realistic optical potentials. Angular and momentum distributions, as well as the energy and nuclear dependence of the total cross section, are studied.
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Serenelli, A., Pena-Garay, C., & Haxton, W. C. (2013). Using the standard solar model to constrain solar composition and nuclear reaction S factors. Phys. Rev. D, 87(4), 043001–9pp.
Abstract: While standard solar model (SSM) predictions depend on approximately 20 input parameters, SSM neutrino flux predictions are strongly correlated with a single model output parameter, the core temperature T-c. Consequently, one can extract physics from solar neutrino flux measurements while minimizing the consequences of SSM uncertainties, by studying flux ratios with appropriate power-law weightings tuned to cancel this T-c dependence. We reexamine an idea for constraining the primordial C + N content of the solar core from a ratio of CN-cycle O-15 to pp-chain B-8 neutrino fluxes, showing that non-nuclear SSM uncertainties in the ratio are small and effectively governed by a single parameter, the diffusion coefficient. We point out that measurements of both CN-I cycle neutrino branches-O-15 and N-13 beta-decay-could, in principle, lead to separate determinations of the core C and N abundances, due to out-of-equilibrium CN-cycle burning in the cooler outer layers of the solar core. Finally, we show that the strategy of constructing “minimum uncertainty” neutrino flux ratios can also test other properties of the SSM. In particular, we demonstrate that a weighted ratio of Be-7 and B-8 fluxes constrains a product of S-factors to the same precision currently possible with laboratory data.
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Albaladejo, M., & Oset, E. (2013). Combined analysis of the pn -> d pi(+)pi(-) and pn -> pn pi(+)pi(-) cross sections and implications for the interpretation of the pn -> d pi(+)pi(-) data. Phys. Rev. C, 88(1), 014006–6pp.
Abstract: We use recent data that show a narrow peak around root s = 2.37 GeV in the pn -> d pi(+)pi(-) cross section, with about double strength at the peak than in the analogous pn -> d pi(0)pi(0) reaction, and, assuming that it is due to the excitation of a dibaryon resonance, we evaluate the cross section for the pn -> pn pi(+)pi(-) reaction, with the final pn unbound but with the same quantum numbers as the deuteron. We use accurate techniques to determine the final state interaction in the case of the pn forming a deuteron or a positive energy state, which allow us to get the pn -> pn pi(+)pi(-) cross section with pn in I = 0 and S = 1, that turns out to be quite close or saturates the experimental pn -> pn pi(+)pi(-) total cross section around root s = 2.37 GeV, depending on the angular momentum assumed. This poses problems to the assumption of the dibaryon hypothesis, which could be rendered more restrictive with future precise data on the pn -> pn pi(+)pi(-) reaction.
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Xiao, C. W., Aceti, F., & Bayar, M. (2013). The small K pi component in the K* wave functions. Eur. Phys. J. A, 49(2), 22–5pp.
Abstract: We use a recently developed formalism which generalizes Weinberg's compositeness condition to partial waves higher than s-wave in order to determine the probability of having a K pi component in the K* wave function. A fit is made to the K pi phase shifts in p-wave, from where the coupling of K* to K pi and the K pi loop function are determined. These ingredients allow us to determine that the K* is a genuine state, different from a K pi component, in a proportion of about 80%.
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Forero, D. V., Morisi, S., Romao, J. C., & Valle, J. W. F. (2013). Neutrino mixing with revamped A(4) flavor symmetry. Phys. Rev. D, 88(1), 016003–7pp.
Abstract: We suggest a minimal extension of the simplest A(4) flavor model that can induce a nonzero theta(13) value, as required by recent neutrino oscillation data from reactors and accelerators. The predicted correlation between the atmospheric mixing angle theta(23) and the magnitude of theta(13) leads to an allowed region substantially smaller than indicated by neutrino-oscillation global fits. Moreover, the scheme correlates CP violation in neutrino oscillations with the octant of the atmospheric mixing parameter theta(23) in such a way that, for example, maximal mixing necessarily violates CP. We briefly comment on other phenomenological features of the model.
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