Bounds on the Solar Antineutrino total Flux and Energy spectrum from the SK experiment

A search for inverse beta decay electron antineutrinos has been carried out using the 825 days sample of solar data obtained at SK. The absence of a significant signal, that is, contributions to the total SK background and their angular variations has set upper bounds on a) the absolute flux of solar antineutrinos originated from ${}^8 B$ neutrinos $\Phi_{\bar{\nu}}({}^8 B)=< 1.8\times 10^5 cm^{-2} s^{-1}$ which is equivalent to an averaged conversion probability bound of P<3.5% (SSM-BP98 model) and b) their differential energy spectrum, the conversion probability is smaller than 8% for all $E_{e,vis}>6.5$ MeV going down the 5% level above $E_{e,vis}\approx 10$ MeV. It is shown that an antineutrino flux would have the net effect of enhancing the SK signal at {\em hep} neutrino energies. The magnitude of this enhancement would highly depend on the, otherwise rather uncertain, steepness of the solar neutrino spectrum at these energies.Comment: 5 pages, 3 ps figure

Baryon asymmetry at the weak phase transition in presence of arbitrary CP violation

We consider interactions of fermions with the domain wall bubbles produced during a first order phase transition. A new exact solution of the Dirac equations is obtained for a wall profile incorporating a position dependent CP violating phase. The reflection coefficients are computed, a resonance effect is uncovered for rapidly varying phases. This resonance effect happens when the energy and mass of the incident particles are $E/m=\Delta\theta/2$. Where $\Delta\theta$ is the phase variation across the wall width. We calculate the chiral charge flux through the wall surface and the corresponding baryon asymmetry of the Universe. It agrees in sign and magnitude with the observed baryonic excess $\rho_B/s\approx 10^{-10}$ for a large range of parameters and CP violation. As a function of $\Delta\theta$, the ratio $\rho_b/s$ reach a maximum for $\Delta\theta\approx 2-4\pi$ and $m\approx m_{top}$. PACS: 11.27.+d, 03.65.-w, 02.30.Hq, 02.30.Gp, 11.30.Fs, 98.80.CqComment: 23 pages, 7 eps figures (epsfig macro neccesary) also avalaible at http://www-itp.unibe.ch/~torrent

On weakly group-theoretical non-degenerate braided fusion categories

We show that the Witt class of a weakly group-theoretical non-degenerate braided fusion category belongs to the subgroup generated by classes of non-degenerate pointed braided fusion categories and Ising braided categories. This applies in particular to solvable nondegenerate braided fusion categories. We also give some sufficient conditions for a braided fusion category to be weakly group-theoretical or solvable in terms of the factorization of its Frobenius-Perron dimension and the Frobenius-Perron dimensions of its simple objects. As an application, we prove that every non-degenerate braided fusion category whose Frobenius-Perron dimension is a natural number less than 1800, or an odd natural number less than 33075, is weakly group-theoretical.Fil: Natale, Sonia Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentin

Massively Parallel Computing at the Large Hadron Collider up to the HL-LHC

As the Large Hadron Collider (LHC) continues its upward progression in energy and luminosity towards the planned High-Luminosity LHC (HL-LHC) in 2025, the challenges of the experiments in processing increasingly complex events will also continue to increase. Improvements in computing technologies and algorithms will be a key part of the advances necessary to meet this challenge. Parallel computing techniques, especially those using massively parallel computing (MPC), promise to be a significant part of this effort. In these proceedings, we discuss these algorithms in the specific context of a particularly important problem: the reconstruction of charged particle tracks in the trigger algorithms in an experiment, in which high computing performance is critical for executing the track reconstruction in the available time. We discuss some areas where parallel computing has already shown benefits to the LHC experiments, and also demonstrate how a MPC-based trigger at the CMS experiment could not only improve performance, but also extend the reach of the CMS trigger system to capture events which are currently not practical to reconstruct at the trigger level.Comment: 14 pages, 6 figures. Proceedings of 2nd International Summer School on Intelligent Signal Processing for Frontier Research and Industry (INFIERI2014), to appear in JINST. Revised version in response to referee comment