Diphoton decay for a 750750 GeV scalar boson in an U(1)XU(1)_{X} model

In the context of a nonuniversal and anomaly free $U(1)_{X}$ extension of the standard model, we examine the decay of a $750$GeV scalar singlet state, $\xi_{\chi}$, as a possible explanation of the observed diphoton excess announced by the ATLAS and CMS collaborations at CERN-LHC collider. One-loop decay to photons is allowed through three heavy singlet quarks and one charged Higgs boson into the loop. We obtain, for different width approximations and for masses of the exotic singlet quarks in the region $[900,\,3000]$ GeV, a production cross section $\sigma(pp\to\xi_{\chi}\to\gamma\gamma)$ compatible with ATLAS and CMS collaborations data. We also include another scalar singlet, $\sigma$, as a dark matter candidate that may couple with the 750 GeV scalar at tree level with production cross sections in agreement with ATLAS and CMS.Comment: 5 figures, discussion extended, 2 new figure

Diphoton decay for a 750 GeV scalar boson in a SU(6)⊗U(1)XSU(6)\otimes U(1)_{X} model

We propose a new $SU(6)\otimes U(1)_{X}$ GUT model free from anomalies, with a 750 GeV scalar candidate which can decay into two photons, compatible with the recent diphoton signal reported by ATLAS and CMS collaborations. This model gives masses to all fermions and may explain the 750GeV signal through one loop decays to $\gamma\gamma$ with charged vector and charged Higgs bosons, as well as up- and electron-like exotic particles that arise naturally from the condition of cancellation of anomalies of the $SU(6)\otimes U(1)_{X}$ group. We obtain, for different width approximations, allowed mass regions from 900 GeV to 3 TeV for the exotic up-like quark, in agreement with ATLAS and CMS collaborations data.Comment: 4 figures, discussion extended, 1 new figur

Leptogenesis in the presence of exact flavor symmetries

In models with flavor symmetries in the leptonic sector leptogenesis can take place in a very different way compared to the standard leptogenesis scenario. We study the generation of a $B-L$ asymmetry in these kind of models in the flavor symmetric phase pointing out that successful leptogenesis requires (i) the right-handed neutrinos to lie in different representations of the flavor group; (ii) the flavons to be lighter at least that one of the right-handed neutrino representations. When these conditions are satisfied leptogenesis proceeds due to new contributions to the CP violating asymmetry and -depending on the specific model- in several stages. We demonstrate the validity of these arguments by studying in detail the generation of the $B-L$ asymmetry in a scenario of a concrete $A_4$ flavor model realization.Comment: 25 pages, 7 figures; version 2: A few clarifications added. Version matches publication in JHE

Análisis de los suelos del piedemoente de la vertiente norte de la Sierra de Alhama (Granada, España)

[Resumen] El piedemonte que enlaza la sierra de Alhama y el poljé de Zafarraya puede considerarse como un glacis incipiente sobre el que desarrollan suelos cuya morfología es heredada del material parental. Los suelos son mayoritariamente Gleysoles y Regosoles, con o sin carbonatos, arcillosos y de fuerte consistencia, motivo que asociado al relieve justifica el alto índice de erosionabilidad y el que exijan un serio acondicionamiento para ser usado agricolamente. Dada la posición fisiográfica y la propia naturaleza edáfica, también se utiliza el terreno para almacenar agua de lluvia destinada a riego. En cuanto a la génesis, son suelos poco Desarrolla dos y el hecho evolutivo más significativo es la transformación de la arcilla heredada (ilita-interestratificados-esmectita).[Abstract] The footslope in between Alhama mountain rouge and Zafarraya polje could be considered as an incipient glacis which shows soil with an inherited morphology from the parent material developing over it. Soils are mainly Gleysols and Regosols, with or without carbonates, clayed and with a strong consistence; these characteristics asociated to relief are the justification of the high erodibility index and the excigence of a serious arranging to be farmerly used. With the fisiographic position and own edaphic nature given, even the land use could be in order to store rainfall water for irrigation. For genetical studies, these are low developed soils and the most significant thing in their evolution is the inherated clay transformation (illite-interstratified-smectite)

Beyond R(D(∗))\mathcal{R}(D^{(*)}) with the general 2HDM-III for b→cτνb\to c\tau\nu

We review the parameter regions allowed by measurements of $\mathcal{R}(D^{(*)})$ and by a theoretical limit on ${\cal B}(B_{c}\to\tau\nu)$ in terms of generic scalar and pseudoscalar new physics couplings, $g_s$ and $g_p$. We then use these regions as constraints to predict the ranges for additional observables in $b\to c\tau\nu$ including the differential decay distributions $d\Gamma/dq^{2}$; the ratios $\mathcal{R}(J/\psi)$ and $\mathcal{R}(\Lambda_{c})$; and the tau-lepton polarisation in $B\to D^{(\star)}\tau\nu$, with emphasis on the CP violating normal polarisation. Finally we map the allowed regions in $g_s$ and $g_p$ into the parameters of four versions of the Yukawa couplings of the general 2HDM-III model. We find that the model is still viable but could be ruled out by a confirmation of a large $\mathcal{R}(J/\psi)$.Comment: 27 pages, 11 figures, major changes with new analysis and plot

Surfaces containing a family of plane curves not forming a fibration

We complete the classification of smooth surfaces swept out by a 1-dimensional family of plane curves that do not form a fibration. As a consequence, we characterize manifolds swept out by a 1-dimensional family of hypersurfaces that do not form a fibration.Comment: Author's post-print, final version published online in Collect. Mat

Scalar coupling limits and diphoton Higgs decay from LHC in an U(1)′U(1)' model with scalar dark matter

In the context of an nonuniversal $U(1)'$ extension of the standard model free from anomalies, we introduce a complex scalar singlet candidate to be dark matter. In addition, an extra scalar doublet and a heavy scalar singlet are required to provide masses to all fermions and to break spontaneously the symmetries. From unitarity and stability of the Higgs potential, we find the full set of bounds and order relations for the scalar coupling constants. Using recent data from the CERN-LHC collider, we study the signal strenght of the diphoton Higgs decay $R_{\gamma \gamma}$, which imposes very stringent bounds to the scalar couplings and other scalar parameters. We obtain constraints in different scenarios of the space of parameters, where decays into dark matter may or may not contribute according to the mass of the scalar dark matter candidate. By assuming that the lightest scalar boson of the model corresponds to the observed Higgs boson, we evaluate deviations from the SM of the trilineal Higgs self-coupling. The conditions from unitarity, stability and Higgs diphoton decay data allow trilineal deviations in the range $0 \leq \delta g \lesssim -72\%$.Comment: Additional figures and analysis in new versio

Numerical Study of the Intrinsic and Feedback Dynamics of a Gas-Solid Fluidized Bed

The aim of this paper is to understand the complex spatio-temporal patterning of the dense bed when the inlet conditions can be modified by the bed itself. In this study, the inlet conditions (fluid pressure and velocity upstream the bed) take into account resistive effects from the distributor and capacitive ones from the air-supply system (plenum). The present work addresses particularly the issue of the transition between multiple and single bubble regimes that occurs for some particular inlet conditions