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Schwetz, T., Tortola, M., & Valle, J. W. F. (2011). Where we are on theta(13): addendum to 'Global neutrino data and recent reactor fluxes: status of three-flavor oscillation parameters'. New J. Phys., 13, 109401–5pp.
Abstract: In this addendum to Schwetz et al (2011 New J. Phys. 13 063004), we consider the recent results from long-baseline nu(mu) -> nu(e) searches at the Tokai to Kamioka (T2K) and Main Injector Neutrino Oscillation Search (MINOS) experiments and investigate their implications for the mixing angle theta(13) and the leptonic Dirac CP phase delta. By combining the 2.5 sigma indication for a nonzero value of theta(13) coming from the T2K data with global neutrino oscillation data, we obtain a significance for theta(13) > 0 of about 3 sigma with best fit points sin(2) theta(13) = 0.013 (0.016) for normal (inverted) neutrino mass ordering. These results depend somewhat on assumptions concerning the analysis of reactor neutrino data.
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Bertone, G., Kong, K. C., Ruiz de Austri, R., & Trotta, R. (2011). Global fits of the minimal universal extra dimensions scenario. Phys. Rev. D, 83(3), 036008–15pp.
Abstract: In theories with universal extra dimensions (UED), the gamma(1) particle, first excited state of the hypercharge gauge boson, provides an excellent dark matter (DM) candidate. Here, we use a modified version of the SUPERBAYES code to perform a Bayesian analysis of the minimal UED scenario, in order to assess its detectability at accelerators and with DM experiments. We derive, in particular, the most probable range of mass and scattering cross sections off nucleons, keeping into account cosmological and electroweak precision constraints. The consequences for the detectability of the gamma(1) with direct and indirect experiments are dramatic. The spin-independent cross section probability distribution peaks at similar to 10(-11) pb, i.e. below the sensitivity of ton-scale experiments. The spin-dependent cross section drives the predicted neutrino flux from the center of the Sun below the reach of present and upcoming experiments. The only strategy that remains open appears to be direct detection with ton-scale experiments sensitive to spin-dependent cross sections. On the other hand, the LHC with 1 fb(-1) of data should be able to probe the current best-fit UED parameters.
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Jung, M., Pich, A., & Tuzon, P. (2011). B(bar) -> X_s gamma rate and CP asymmetry within the aligned two-Higgs-doublet model. Phys. Rev. D, 83(7), 074011–8pp.
Abstract: In the two-Higgs-doublet model the alignment of the Yukawa matrices in flavor space guarantees the absence of flavor-changing neutral currents at tree level, while introducing new sources for CP violation parametrized in a very economical way [Antonio Pich and Paula Tuzon, Phys. Rev. D 80, 091702 (2009)]. This implies a potentially large influence in a number of processes, b -> s gamma being a prominent example where rather high experimental and theoretical precision meet. We analyze the CP rate asymmetry in this inclusive decay and determine the resulting constraints on the model parameters. We demonstrate the compatibility with previously obtained limits [Martin Jung, Antonio Pich, and Paula Tuzon, J. High Energy Phys. 11 (2010) 003]. Moreover, we extend the phenomenological analysis of the branching ratio, and examine the influence of resulting correlations on the like-sign dimuon charge asymmetry in B decays.
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Barenboim, G., & Panotopoulos, G. (2011). Direct neutralino searches in the NMSSM with gravitino LSP in the degenerate scenario. J. High Energy Phys., 08(8), 027–16pp.
Abstract: In the present work a two-component dark matter model is studied adopting the degenerate scenario in the R-parity conserving NMSSM. The gravitino LSP and the neutralino NLSP are extremely degenerate in mass, avoiding the BBN bounds and obtaining a high reheating temperature for thermal leptogenesis. In this model both gravitino (absolutely stable) and neutralino (quasi-stable) contribute to dark matter, and direct detection searches for neutralino are discussed. Points that survive all the constraints correspond to a singlino-like neutralino.
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LHCf Collaboration(Adriani, O. et al), Faus-Golfe, A., & Velasco, J. (2011). Measurement of zero degree single photon energy spectra for sqrt(s) = 7 TeV proton-proton collisions at LHC. Phys. Lett. B, 703(2), 128–134.
Abstract: In early 2010. the Large Hadron Collider forward (LHCf) experiment measured very forward neutral particle spectra in LHC proton-proton collisions. From a limited data set taken under the best beam conditions (low beam-gas background and low occurrence of pile-up events), the single photon spectra at root s = 7 TeV and pseudo-rapidity (eta) ranges from 8.81 to 8.99 and from 10.94 to infinity were obtained for the first time and are reported in this Letter. The spectra from two independent LHCf detectors are consistent with one another and serve as a cross check of the data. The photon spectra are also compared with the predictions of several hadron interaction models that are used extensively for modeling ultra-high energy cosmic-ray showers. Despite conservative estimates for the systematic errors, none of the models agree perfectly with the measurements. A notable difference is found between the data and the DPMJET 3.04 and PYTHIA 8.145 hadron interaction models above 2 TeV where the models predict higher photon yield than the data. The QGSJET II-03 model predicts overall lower photon yield than the data, especially above 2 TeV in the rapidity range 8.81 < eta < 8.99.
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