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

The Cradle Song (December 8, 1944)

Program for The Cradle Song (December 8, 1944)

The Romantic Young Lady (December 17, 1929)

Program for The Romantic Young Lady (December 17, 1929)

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

The Cradle Song (March 20, 1959)

Program for The Cradle Song (March 20, 1959) To view the photos from this production of The Cradle Song, please click here

The Cradle Song (March 14-16, 1951)

Program for The Cradle Song (March 14-16, 1951). To view the photos from this production of The Cradle Song, please click here

Cradle Song (March 12-13, 1965)

Program for Cradle Song (March 12-13, 1965)

BB meson anomalies and large B+→K+ννˉB^{+}\to K^{+}\nu\bar{\nu} in non-universal U(1)′U(1)^\prime models

In view of both the latest LHCb measurement of $R_{K^{(*)}}$ and the new $2.8\sigma$ deviation reported by Belle II on $B^{+}\to K^{+}\nu\bar{\nu}$ decays, we present a fit to the $B$ meson anomalies for various one and two dimensional hypothesis including complex Wilson coefficients. We show in a model-independent way that the generic non-universal $U(1)^{\prime}$ extensions of the SM, without flavour violation, fail to simultaneously fit those observables and corroborate that they can modify $\mathrm{BR}(B^{+}\to K^{+}\nu\bar{\nu})$ up to only a $10\%$. In view of this deficit, we propose a new way in which those models can accommodate the data at tree level by introducing lepton flavour violating couplings and non-diagonal elements of the charged lepton mixing matrix, with implications in future charged lepton flavour violation searches.Comment: 16 pages, 5 figures, 2 tables, charged lepton flavour violating constraints added, new citations include

How important is the European economic and monetary union in the foreign trade with the EU-27 countries? Empirical evidence from Spain

This paper analyzes the effect of the European Economic and Monetary Union on export flows from a Spanish region (Castilla y Leon) to the EU-27 countries during the last years Applying static panel data estimation technique, this study finds that exporter and importer incomes, exporter population, distance, and a common land border are the main explanatory factors of exports from this Spanish region. Moreover, the EU membership of the importer country only caused positive and significant effects between 1994 and 1996, whereas the EMU membership reduced export flows from Castilla y Leon to the European countries during the whole period.peer-reviewe

The Colombian Banking Sector: Analysis from Relative Efficiency

The banking sector is that sector of the modern economy that is primarily called upon to play the important role of intermediation between the surplus agents and the deficit agents. Based on this fact, this research presents and analyzes the behavior of banks in Colombia since 2002 and up to 2016 (15 years) through the application of data envelopment analysis, a nonparametric methodology of advanced linear programming, which generates a single efficiency indicator for each unit studied in each period, optimizing multiple resources (inputs) and multiple products (outputs). One aspect of the results shows that for the year 2014, 71% of the banks were efficient, this being the highest result within the period studied