
XENON100 Collaboration(Aprile, E. et al), & Orrigo, S. E. A. (2014). First axion results from the XENON100 experiment. Phys. Rev. D, 90(6), 062009–7pp.
Abstract: We present the first results of searches for axions and axionlike particles with the XENON100 experiment. The axionelectron coupling constant, g(Ae), has been probed by exploiting the axioelectric effect in liquid xenon. A profile likelihood analysis of 224.6 live days x 34kg exposure has shown no evidence for a signal. By rejecting g(Ae) larger than 7.7 x 10(12) (90% C. L.) in the solar axion search, we set the best limit to date on this coupling. In the frame of the DFSZ and KSVZ models, we exclude QCD axions heavier than 0.3 and 80 eV/c(2), respectively. For axionlike particles, under the assumption that they constitute the whole abundance of dark matter in our galaxy, we constrain gAe to be lower than 1 x 10(12) (90% C.L.) for masses between 5 and 10 keV/c(2).



T2K Collaboration(Abe, K. et al), CerveraVillanueva, A., Escudero, L., GomezCadenas, J. J., Izmaylov, A., Monfregola, L., et al. (2014). Observation of Electron Neutrino Appearance in a Muon Neutrino Beam. Phys. Rev. Lett., 112(6), 061802–8pp.
Abstract: The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the SuperKamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3 sigma when compared to 4.92 +/ 0.55 expected background events. In the PontecorvoMakiNakagawaSakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles theta(12), theta(23), theta(13), a mass difference vertical bar Delta m(32)(2)vertical bar and a CP violating phase delta(CP). In this neutrino oscillation scenario, assuming vertical bar Delta m(32)(2)vertical bar = 2.4 x 10(3) eV(2), sin theta(2)(23) = 0.5, and vertical bar Delta m(32)(2)vertical bar > 0 (vertical bar Delta m(32)(2)vertical bar < 0), a best fit value of sin2 theta(2)(13) = 0.140( 0.032)(+0.038) (0.170(0.037)(+0.045)) is obtained at delta(CP) = 0. When combining the result with the current best knowledge of oscillation parameters including the world average value of theta(13) from reactor experiments, some values of delta(CP) are disfavored at the 90% C. L.



Pastore, A., Davesne, D., & Navarro, J. (2014). Nuclear matter response function with a central plus tensor Landau interaction. J. Phys. G, 41(5), 055103–17pp.
Abstract: We present a method to obtain response functions in the random phase approximation (RPA) based on a residual interaction described in terms of Landau parameters with central plus tensor contributions. The response functions keep the explicit momentum dependence of the RPA, in contrast with the traditional Landau approximation. Results for symmetric nuclear matter and pure neutron matter are presented using Landau parameters derived from finiterange interactions, both phenomenological and microscopic. We study the convergence of response functions as the number of Landau parameters is increased.



Boucenna, M. S., Morisi, S., Shafi, Q., & Valle, J. W. F. (2014). Inflation and majoron dark matter in the neutrino seesaw mechanism. Phys. Rev. D, 90(5), 055023–6pp.
Abstract: We propose that inflation and dark matter have a common origin, connected to the neutrino mass generation scheme. As a model we consider spontaneous breaking of global lepton number within the seesaw mechanism. We show that it provides an acceptable inflationary scenario consistent with the recent cosmic microwave background Bmode observation by the BICEP2 experiment. The scheme may also account for the baryon asymmetry of the Universe through leptogenesis for reasonable parameter choices.



Arbelaez, C., Kolesova, H., & Malinsky, M. (2014). Witten's mechanism in the flipped SU(5) unification. Phys. Rev. D, 89(5), 055003–16pp.
Abstract: We argue that Witten's loop mechanism for the righthanded Majorana neutrino mass generation identified originally in the SO(10) grand unification context can be successfully adopted to the class of the simplest flipped SU(5) models. In such a framework, the main drawback of the SO(10) prototypein particular, the generic tension among the gauge unification constraints and the absolute neutrino mass scaleis alleviated, and a simple yet potentially realistic and testable scenario emerges.



Ledwig, T., Martin Camalich, J., Geng, L. S., & Vicente Vacas, M. J. (2014). Octetbaryon axialvector charges and SU(3)breaking effects in the semileptonic hyperon decays. Phys. Rev. D, 90(5), 054502–16pp.
Abstract: The octetbaryon axialvector charges and the g(1)/f(1) ratios measured in the semileptonic hyperon decays are studied up to O(p(3)) using the covariant baryon chiral perturbation theory with explicit decuplet contributions. We clarify the role of different lowenergy constants and find a good convergence for the chiral expansion of the axialvector charges of the baryon octet, g(1)(0), with O(p(3)) corrections typically around 20% of the leading ones. This is a consequence of strong cancellations between different nexttoleading order terms. We show that considering only nonanalytic terms is not enough and that analytic terms appearing at the same chiral order play an important role in this description. The same effects still hold for the chiral extrapolation of the axialvector charges and result in a rather mild quarkmass dependence. As a result, we report a determination of the leadingorder chiral couplings, D = 0.623(61)(17) and F = 0.441(47)(2), as obtained from a completely consistent chiral analysis up to O(p(3)). Furthermore, we note that the appearance of an unknown lowenergy constant precludes the extraction of the proton octet charge from semileptonic decay data alone, which is relevant for an analysis of the composition of the proton spin.



Wendt, A. et al, & Algora, A. (2014). Isospin symmetry in the sd shell: Transition strengths in the neutrondeficient sd shell nucleus Ar33. Phys. Rev. C, 90(5), 054301–7pp.
Abstract: Reduced transition strengths of the deexciting transitions from the first two excited states in Ar33 were measured in a relativistic Coulomb excitation experiment at the GSI Helmholtz center. The radioactive ion beam was produced by fragmentation of a primary Ar36 beam on a Be9 target followed by the selection of the reaction product of interest via the GSI Fragment Separator. The (33A)r beam hit a secondary Au197 target with an energy of approximately 145 MeV/nucleon. An array of highpurity germanium cluster detectors and largevolume BaF2 scintillator detectors were employed for gammaray spectroscopy at the secondary target position. The LundYorkCologne Calorimeter was used to track the outgoing ions and to identify the nuclear reaction channels. For the two lowest energy excited states of Ar33 the reduced transition strengths have been determined. With these first results the Tz = 3/2 nucleus Ar33 is now, together with Na21 (Tz = 1/2), the only neutrondeficient oddA sd shell nucleus in which experimental transition strengths are available. The experimental values are compared to results of shellmodel calculations which describe simultaneously mirrorenergy differences and transitionstrength values of mirror pairs in the sd shell in a consistent way.



Gomez Dumm, D., Noguera, S., Scoccola, N. N., & Scopetta, S. (2014). Pion distribution amplitude and the pionphoton transition form factor in a nonlocal chiral quark model. Phys. Rev. D, 89(5), 054031–14pp.
Abstract: We study the pion distribution amplitude (pi DA) in the context of a nonlocal chiral quark model. The corresponding Lagrangian reproduces the phenomenological values of the pion mass and decay constant, as well as the momentum dependence of the quark propagator obtained in lattice calculations. It is found that the obtained pi DA has two symmetric maxima, which arise from the new contributions generated by the nonlocal character of the interactions. This pi DA is applied to leading order and nexttoleading order calculations of the pionphoton transition form factor. Implications of the results are discussed.



Liang, W. H., Xiao, C. W., & Oset, E. (2014). Baryon states with open beauty in the extended local hidden gauge approach. Phys. Rev. D, 89(5), 054023–15pp.
Abstract: In this paper, we examine the interaction of (B) over barN, (B) over bar Delta, (B) over bar *N, and (B) over bar*Delta states, together with their coupled channels, by using a mapping from the light meson sector. The assumption that the heavy quarks act as spectators at the quark level automatically leads us to the results of the heavy quark spin symmetry for pion exchange and reproduces the results of the Weinberg Tomozawa term, coming from light vector exchanges in the extended local hidden gauge approach. With this dynamics we look for states dynamically generated from the interaction and find two states with nearly zero width, which we associate to the A(b)(5912) and A(b)(5920) states. The states couple mostly to (B) over bar *N, which are degenerate with the Weinberg Tomozawa interaction. The difference of masses between these two states, with J = 1/2 and 3/2, respectively, is due to pion exchange connecting these states to intermediate (B) over barN states. In addition to these two A(b) states, we find three more states with I = 0, one of them nearly degenerate in two states of J = 1/2, 3/2. Furthermore, we also find eight more states in I = 1, two of them degenerate in J = 1/2, 3/2, and another two degenerate in J = 1/2, 3/2, 5/2.



Krzysiek, M. et al, Gadea, A., Huyuk, T., & Barrientos, D. (2014). Study of the soft dipole modes in Ce140 via inelastic scattering of O17. Phys. Scr., 89(5), 054016–6pp.
Abstract: The main aim of this study was a deeper understanding of the nuclear structure properties of the soft dipole modes in Ce140, excited via inelastic scattering of weakly bound O17 projectiles. An important aim was to investigate the 'splitting' of the PDR into two parts: a lowenergy isoscalar component dominated by neutronskin oscillations and a higherenergy component lying on the tail of the giant dipole resonance of a rather isovector character. This was already observed for this nucleus, investigated in (alpha, alpha') and (gamma,gamma') experiments. The experiment was performed at Laboratori Nazionali di Legnaro, Italy. Inelastic scattering of O17 ion beam at 20 MeV A(1) was used to excite the resonance modes in the Ce140 target. Gammarays were registered by five triple clusters of AGATADemonstrator and nine large volume scintillators (LaBr3). The scattered O17 ions were identified by two Delta E – E Si telescopes of the TRACE array mounted inside the scattering chamber. The telescopes consisted of two segmented Sipad detectors, each of 60 pixels. Very preliminary data have shown a strong domination of the E1 transitions in the 'pygmy' region with a character more similar to the one obtained in alpha scattering experiment.

