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Dawson, K. S. et al, de Putter, R., & Mena, O. (2013). The Baryon Oscillation Spectroscopic Survey of SDSS-III. Astron. J., 145(1), 10–41pp.
Abstract: The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg(2) to measure BAO to redshifts z < 0.7. Observations of neutral hydrogen in the Ly alpha forest in more than 150,000 quasar spectra (g < 22) will constrain BAO over the redshift range 2.15 < z < 3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Ly alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance d(A) to an accuracy of 1.0% at redshifts z = 0.3 and z = 0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Ly alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D-A(z) and H-1(z) parameters to an accuracy of 1.9% at z similar to 2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.
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Goel, N., Domingo-Pardo, C., Habermann, T., Ameil, F., Engert, T., Gerl, J., et al. (2013). Characterisation of a symmetric AGATA detector using the gamma-ray imaging scanning technique. Nucl. Instrum. Methods Phys. Res. A, 700, 10–21.
Abstract: The imaging scanning technique for the characterisation of large volume, highly segmented, HPGe detectors is demonstrated by comparing the measured spatial response of a symmetric AGATA crystal versus the theoretical calculations obtained with the Multi-Geometry Simulation (MGS) code. The signal rise-times measured as a function of the gamma-ray interaction positions, in both coaxial and planar regions of the detection volume, are presented and confronted with the expected behaviour obtained via MGS. The transition in charge carrier transport behaviour as a function of the depth is studied for the region of the complex electric field. In general, a fairly good agreement between theory and experiment is obtained. Only systematic deviations between simulation and measurement are observed in the critical front part of the AGATA detector. They may be ascribed to a non-linear impurity concentration profile of the germanium crystal.
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Olmo, G. J., & Rubiera-Garcia, D. (2014). Semiclassical geons at particle accelerators. J. Cosmol. Astropart. Phys., 02(2), 010–25pp.
Abstract: We point out that in certain four-dimensional extensions of general relativity constructed within the Palatini formalism stable self-gravitating objects with a discrete mass and charge spectrum may exist. The incorporation of nonlinearities in the electromagnetic field may effectively reduce their mass spectrum by many orders of magnitude. As a consequence, these objects could be within (or near) the reach of current particle accelerators. We provide an exactly solvable model to support this idea.
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de Azcarraga, J. A., Fedoruk, S., Izquierdo, J. M., & Lukierski, J. (2015). Two-twistor particle models and free massive higher spin fields. J. High Energy Phys., 04(4), 010–39pp.
Abstract: We present D = 3 and D = 4 world-line models for massive particles moving in a new type of enlarged spacetime, with D-1 additional vector coordinates, which after quantization lead to towers of massive higher spin (HS) free fields. Two classically equivalent formulations are presented: one with a hybrid spacetime/bispinor variables and a second described by a free two-twistor dynamics with constraints. After first quantization in the D = 3 and D = 4 cases, the wave functions satisfying a massive version of Vasiliev's free unfolded equations are given as functions on the SL(2, R) and SL(2, C) group manifolds respectively, which describe arbitrary on-shell momenta and spin degrees of freedom. Further we comment on the D = 6 case, and possible supersymmetric extensions are mentioned as well. Finally, the description of interactions and the Ads/crr duality are briefly considered for massive IHS fields.
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Anamiati, G., Hirsch, M., & Nardi, E. (2016). Quasi-Dirac neutrinos at the LHC. J. High Energy Phys., 10(10), 010–19pp.
Abstract: Lepton number violation is searched for at the LHC using same-sign leptons plus jets. The standard lore is that the ratio of same-sign lepton to opposite-sign lepton events, R-ll, is equal to R-ll = 1 (R-ll = 0) for Majorana (Dirac) neutrinos. We clarify under which conditions the ratio Rll can assume values different from 0 and 1, and we argue that the precise value 0 < R-ll < 1 is controlled by the mass splitting versus the width of the quasi-Dirac resonances. A measurement of R-ll not equal 0, 1 would then contain valuable information about the origin of neutrino masses. We consider as an example the inverse seesaw mechanism in a left-right symmetric scenario, which is phenomenologically particularly interesting since all the heavy states in the high energy completion of the model could be within experimental reach. A prediction of this scenario is a correlation between the values of R-ll and the ratio between the rates for heavy neutrino decays into standard model gauge bosons, and into three body final states ljj mediated by off-shell W-R exchange.
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