With the LHC experiments gathering more data, the exploration of the symmetry breaking sector of the Standard Model will gain renewed impetus. Likewise, it is important to search for dark matter candidates being a degree of freedom missing in the Standard Model. An invisible axion is an interesting candidate for dark matter. However trying to look for direct evidence of its existence at the LHC is hopeless as it is extremely weakly coupled. Therefore we have to resort to less direct ways to explore this sector by formulating consistent models that include the axion and deriving consequences that could be experimentally tested. In this talk we explored such consequences in the DFS model, an extension of the 2HDM with axion.

Scopri di più »# Tag Archives: Evento scientifico

## Latest results from the OPERA experiment

The OPERA experiment at the Gran Sasso underground laboratory has been designed to study the νμ→ντ oscillation in appearance mode in the CNGS neutrino beam. The efforts of the Collaboration to extend the analysed data sample, with five identified ντ candidates overall, and to improve the knowledge of the expected background allowed to establish the discovery of νμ→ντ oscillation with a significance larger than 5 σ. In this talk, the ντ data analysis will be discussed, with emphasis on the background constraints obtained by using dedicated data-driven control samples. The analysis of the present τ neutrino and electron neutrino samples in the framework of the 3+1 sterile model will be presented. Finally the analysis of the muon charge ratio in the cosmic ray sample will be covered.

Scopri di più »## Flavored Z_N symmetries

Discrete Z_N symmetries are a common “artifact” of beyond the standard model physics models. They provide different avenues for constructing consistent scenarios for lepton and quark mixing patterns, radiative neutrino mass generation as well as dark matter stabilization. In this talk I will show how these symmetries can be derived from the spontaneous breaking of the Abelian U(1) factors contained in the global flavor symmetry transformations of the gauge invariant kinetic Lagrangian. I will show how this idea can be implemented in scenarios with right-handed neutrinos.

Scopri di più »## Status of SuperKEKB Project: Accelerator Design and Construction Progress

The SuperKEKB project is a positron-electron collider built to explore new phenomena in particle physics. The physics program of the next B- factory delivering ultra high statistics is almost independent of, and/or complementary to, the high energy experiments at the LHC. The target luminosity is 8×10^35 cm^-2s^-1, which is 40 times the performance of the previous KEKB accelerator, which has been operated during 11 years until 2010. The consideration of SuperKEKB began in 2001. The strategy for the luminosity upgrade was a high-current scheme in the early stage. However,difficulties such as a bunch lengthening due to coherent synchrotron radiation and the need for a huge reinforcement of the RF system were encountered. As a result, in 2009 we have changed the strategy from the previous high-current to a novel “nano-beam” scheme. The nano-beam scheme was first proposed by P. Raimondi in Italy. Here the collision of low emittance beams under a large crossing angle allows squeezing the beta function at IP to values much smaller than the bunch length. Consequently, the 40 times higher target luminosity can be achieved with only twice the beam current of KEKB. The commissioning of SuperKEKB will start in early next year. In this seminar the latest upgrade schedule and the recent progress of the accelerator construction will be presented.

Scopri di più »## Consiglio di Laboratorio – Preventivi per il 2016

## LNF Mini-Workshop Series: Rewarding Science

The Frascati National Laboratories organize the first edition of a workshop dedicated to the young researchers whose PHD theses have been awarded by INFN scientific committees. It is an opportunity for these young scientists to illustrate their work to their colleagues. All different INFN scientific areas will be covered. ▪ 2014 Award “Marcello Conversi” for Lines of Research I ▪ 2014 Award “Bruno Rossi” for Lines of Research II ▪ 2014 Award “Claudio Villi” for Lines of Research III ▪ 2014 Award “Sergio Fubini” for Lines of Research IV ▪ 2014 Award “Francesco Resmini” for Lines of Research V

Scopri di più »## Experimental spectroscopy of pionic atoms and eta’-mesic nuclei – Mass generation mechanism of the pseudo-scalar mesons

Abstract. I will report our recent experimental studies on pionic atoms and eta'-mesic nuclei. Pionic atoms are known to provide irreplaceable information on the pion-nucleus interaction. Our recent spectroscopy of pionic atoms in (d,3He) reactions provides very high precision information on the binding energies and widths, and thus we expect more stringent constraints to be set to the pion-nucleus interaction. In the presentation, our recent activities on an experiment for eta' mesic nuclei search at GSI/FAIR will also be discussed in the context of the mass generation mechanism of the mesons.

Scopri di più »## Induced vacuum bosonic current in a cosmic string spacetime

Cosmic strings are linear gravitational stable topological defects which may have been created as a consequence of phase transitions in the early universe. The formation of cosmic strings can have astrophysical and cosmological consequences. The geometry of the spacetime associated with an idealized cosmic string, i.e. infinitely long and straight, is locally flat except on the string. In quantum field theory, the corresponding nontrivial topology induces non-zero vacuum expectation values (VEVs) for physical observables. In this talk, we analyze the bosonic current densities induced by a magnetic flux running along an idealized cosmic string, admitting that the coordinate along the string’s axis is compactified. Additionally, we admit the presence of a magneti flux enclosed by the compactification axis. In order to develop this analysis, we calculate the complete set of normalized bosonic wave functions obeying a quasiperiodicity condition along the compactified dimension. In this context, only azimuthal and axial currents densities take place.

Scopri di più »## Constructive Renormalization Group: A conference in memory of Pierluigi Falco

Aim of the conference is to present recent results in the rigorous renormalization group approach developed for constructive QFT and statistical physics. In this context, we want to remember our friend and colleague Pierluigi Falco who gave important contributions to this field during his short life. The conference is financed by the PRIN 2010 "Teorie geometriche e analitiche dei sistemi Hamiltoniani in dimensioni finite e infinite" (P.I. Carlangelo Liverani), by the FIR 2013 "Condensed Matter in Mathematical Physics" (COND-MATH) (P.I. Michele Correggi), and by GNFM-INdAM. The conference is an activity that fits within the convention between the INFN and the Centre for Mathematics and Theoretical Physics (CMTP), University of Rome Tor Vergata. Invited Speakers: A. Abdesselam, G. Benfatto , F. Bonetto, R. Bauerschmidt, D. Brydges, M. Correggi, A. Ferraz, J. Fröhlich, G. Gallavotti, A. Giuliani, C. Kopper, G. Jona Lasinio, V. Mastropietro, P. Mitter, M. Porta, T. Spencer, B. Scoppola Organizers: G. Benfatto, M. Lombardo, V. Mastropietro, A. Pizzo

Scopri di più »## Runge-Lenz vector and Stark effect in Calogero-Coulomb problem

We show that deformation N-dimensional (Euclidean, spherical and hyperbolic) Coulomb system by the patential of rational Calogero model preserves superintegrability property of Coulomb problem. Then we find explicit expression of the Runge-Lenz vector and symmetry algebra of rational Calogero-Coulomb problem, formulated in terms of Dunkl operators. We find that they are proper deformations of their Coulomb counterparts. This observation permits to claim that most of properties of Coulomb and oscillator systems can be lifted to their Calogero-extended analogs by the proper replacement of momenta by Dunkl momenta operators. Particularly , we show that N-dimensional Calogero-Coulomb system preserves integrability property in the presence of Stark term, and construct its complete set of constants of motion. We find, that in parabolic coordinates the systems admits complete separation of variables for N=2,3 and partial ones for $N>3$. The system possesses linear Stark effect and find its explicit expression.Finally, we show, that two-center Calodjero-Coulomb problem is also integrable systems, which admits, in elliptic coordinates, the complet separation of variables for N=2,3 and partial ones for N>3.

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