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Bayar, M., & Oset, E. (2012). Improved fixed center approximation of the Faddeev equations for the (K)over-bar N N system with S=0. Nucl. Phys. A, 883, 57–68.
Abstract: We extend the Fixed Center Approximation (FCA) to the Faddeev equations for the (K) over bar N N system with S = 0, including the charge exchange mechanisms in the (K) over bar rescattering which have been ignored in former works within the FCA. We obtain similar results to those found before, but the binding is reduced by 6 MeV. At the same time we also evaluate the explicit contribution the pi N Sigma intermediate state in the three body system and find that it produces and additional small decrease in the binding of about 3 MeV. The system appears bound by about 35 MeV and the width omitting two body absorption, is about 50 MeV.
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Shekhovtsova, O., Przedzinski, T., Roig, P., & Was, Z. (2012). Resonance chiral Lagrangian currents and tau decay Monte Carlo. Phys. Rev. D, 86(11), 113008–32pp.
Abstract: In the present paper we describe the set of form factors for hadronic tau decays based on Resonance Chiral Theory. The technical implementation of the form factors in FORTRAN code is also explained. It is shown how it can be installed into the TAUOLA Monte Carlo program. Then it is rather easy to implement into software environments of not only Belle and BABAR collaborations but also for FORTRAN and C ++ applications of LHC. The description of the current for each tau decay mode is complemented with technical numerical tests. The set is ready for fits, paramxers to be used in fits are explained. Arrangements to work with the experimental data not requiring unfolding are prepared. Hadronic currents, ready for confrontation with the tau decay data, but not yet ready for the general use, cover more than 88% of hadronic tau decay width.
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Barry, J., Dorame, L., & Rodejohann, W. (2012). Linear collider test of a neutrinoless double beta decay mechanism in left-right symmetric theories. Eur. Phys. J. C, 72(5), 2023–11pp.
Abstract: There are various diagrams leading to neutrinoless double beta decay in left-right symmetric theories based on the gauge group SU(2)(L) x SU(2)(R). All can in principle be tested at a linear collider running in electron-electron mode. We argue that the so-called lambda-diagram is the most promising one. Taking the current limit on this diagram from double beta decay experiments, we evaluate the relevant cross section e(-)e(-) -> WL-WR-, where W-L(-) is the Standard Model W-boson and W-R(-) the one from SU(2)(R). It is observable if the life-time of double beta decay and the mass of the W-R are close to current limits. Beam polarization effects and the high-energy behaviour of the cross section are also analyzed.
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Espinoza, C., Lazauskas, R., & Volpe, C. (2012). Search for new physics with neutrinos at radioactive ion beam facilities. Phys. Rev. D, 86(11), 113016–10pp.
Abstract: We propose applications of radioactive ion beam facilities to investigate physics beyond the Standard Model. In particular, we focus upon the search for sterile neutrinos and the possible measurement of coherent neutrino-nucleus scattering, by means of a low-energy beta beam with a Lorentz boost factor gamma approximate to 1. In both cases, we consider Li-8 and B-8 ions as neutrino sources. In the considered setup, the collected radioactive ions are sent inside a 4 pi detector. For the first application, we provide the number of events associated with neutrino-nucleus coherent scattering, when the detector is filled with a noble liquid. For the sterile search, we consider that the spherical detector is filled with a liquid scintillator, and that the neutrino detection channel is inverse beta decay. We provide the exclusion curves for the sterile neutrino mixing parameters, based upon the 3 _ 1 formalism, depending upon the achievable ion intensity. Our results are obtained both from total rates, and by including spectral information with binning in energy and in distance. The proposed experiment represents a possible alternative to clarify the current anomalies observed in neutrino experiments.
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Bernabeu, J., Martinez-Vidal, F., & Villanueva-Perez, P. (2012). Time reversal violation from the entangled B-0(B)over-bar(0) system. J. High Energy Phys., 08(8), 064–18pp.
Abstract: We discuss the concepts and methodology to implement an experiment probing directly Time Reversal (T) non-invariance, without any experimental connection to CP violation, by the exchange of in and out states. The idea relies on the B-0(B) over bar (0)) entanglement and decay time information available at B factories. The flavor or CP tag of the state of the still living neutral meson by the first decay of its orthogonal partner overcomes the problem of irreversibility for unstable systems, which prevents direct tests of T with incoherent particle states. T violation in the time evolution between the two decays means experimentally a difference between the rates for the time-ordered (l+X, J/psi K-s) and (J/psi K-L, l(-)X) decays, and three other independent asymmetries. The proposed strategy has been applied to simulated data samples of similar size and features to those currently available, from which we estimate the significance of the expected discovery to reach many standard deviations.
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