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Afonso, V. I., Olmo, G. J., & Rubiera-Garcia, D. (2017). Scalar geons in Born-Infeld gravity. J. Cosmol. Astropart. Phys., 08(8), 031–35pp.
Abstract: The existence of static, spherically symmetric, self-gravitating scalar field solutions in the context of Born-Infeld gravity is explored. Upon a combination of analytical approximations and numerical methods, the equations for a free scalar field (without a potential term) are solved, verifying that the solutions recover the predictions of General Relativity far from the center but finding important new effects in the central regions. We find two classes of objects depending on the ratio between the Schwarzschild radius and a length scale associated to the Born-Infeld theory: massive solutions have a wormhole structure, with their throat at r = 2 M, while for the lighter configurations the topology is Euclidean. The total energy density of these solutions exhibits a solitonic profile with a maximum peaked away from the center, and located at the throat whenever a wormhole exists. The geodesic structure and curvature invariants are analyzed for the various configurations considered.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2017). Search for new resonances decaying to a W or Z boson and a Higgs boson in the l(+)l(-)b(b)over-bar, l nu b(b)over-bar, and nu(nu)over-barb(b)over-bar channels with pp collisions at root s=13 TeV with the ATLAS detector. Phys. Lett. B, 765, 32–52.
Abstract: A search is presented for new resonances decaying to a W or Z boson and a Higgs boson in the l(+)l(-)b (b) over bar, l nu b (b) over bar, and nu(nu) over barb (b) over bar channels in pp collisions at root s = 13 TeV with the ATLAS detector at the Large Hadron Collider using a total integrated luminosity of 3.2 fb(-1). The search is conducted by looking for a localized excess in the WH/ZH invariant or transverse mass distribution. No significant excess is observed, and the results are interpreted in terms of constraints on a simplified model based on a phenomenological Lagrangian of heavy vector triplets.
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de Salas, P. F., Gariazzo, S., Lesgourgues, J., & Pastor, S. (2017). Calculation of the local density of relic neutrinos. J. Cosmol. Astropart. Phys., 09(9), 034–24pp.
Abstract: Nonzero neutrino masses are required by the existence of flavour oscillations, with values of the order of at least 50 meV. We consider the gravitational clustering of relic neutrinos within the Milky Way, and used the N – one-body simulation technique to compute their density enhancement factor in the neighbourhood of the Earth with respect to the average cosmic density. Compared to previous similar studies, we pushed the simulation down to smaller neutrino masses, and included an improved treatment of the baryonic and dark matter distributions in the Milky Way. Our results are important for future experiments aiming at detecting the cosmic neutrino background, such as the Princeton Tritium Observatory for Light, Early-universe, Massive-neutrino Yield (PTOLEMY) proposal. We calculate the impact of neutrino clustering in the Milky Way on the expected event rate for a PTOLEMY-like experiment. We find that the effect of clustering remains negligible for the minimal normal hierarchy scenario, while it enhances the event rate by 10 to 20% (resp. a factor 1.7 to 2.5) for the minimal inverted hierarchy scenario (resp. a degenerate scenario with 150 meV masses). Finally we compute the impact on the event rate of a possible fourth sterile neutrino with a mass of 1.3 eV.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2017). Search for new phenomena with large jet multiplicities and missing transverse momentum using large-radius jets and flavour-tagging at ATLAS in 13 TeV pp collisions. J. High Energy Phys., 12(12), 034–52pp.
Abstract: A search is presented for particles that decay producing a large jet multiplicity and invisible particles. The event selection applies a veto on the presence of isolated electrons or muons and additional requirements on the number of b-tagged jets and the scalar sum of masses of large-radius jets. Having explored the full ATLAS 2015-2016 dataset of LHC proton-proton collisions at root s = 13 TeV, which corresponds to 36.1 fb(-1) of integrated luminosity, no evidence is found for physics beyond the Standard Model. The results are interpreted in the context of simplified models inspired by R-parity-conserving and R-parity-violating supersymmetry, where gluinos are pair-produced. More generic models within the phenomenological minimal supersymmetric Standard Model are also considered.
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Reig, M., Valle, J. W. F., & Vaquera-Araujo, C. A. (2017). Unifying left-right symmetry and 331 electroweak theories. Phys. Lett. B, 766, 35–40.
Abstract: We propose a realistic theory based on the SU(3) c. SU(3) L. SU(3) R. U(1) Xgauge group which requires the number of families to match the number of colors. In the simplest realization neutrino masses arise from the canonical seesaw mechanism and their smallness correlates with the observed V-A nature of the weak force. Depending on the symmetry breaking path to the Standard Model one recovers either a left-right symmetric theory or one based on the SU(3) c. SU(3) L. U(1) symmetry as the “next” step towards new physics.
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