Search

Abstract The Large Hadron Collider is reaching energies never achieved before allowing the search for exotic particles in the TeV mass range. In a continuing effort to find monopoles we discuss the effect of the magnetic dipole field created by a pair of monopole–anti-monopole or monopolium on the successive bunches of charged particles in the beam at LHC.

Abstract Two-parton correlations in the pion are investigated in terms of double parton distribution functions. A Poincaré covariant light-front framework has been adopted. As non perturbative input, the pion wave function obtained within the so-called soft-wall AdS/QCD model has been used. Results show how novel dynamical information on the structure of the pion, not accessible through one-body quantities, are encoded in double parton distribution functions.

A first attempt to apply the AdS/QCD framework for a bottom–up approach to the evaluation of the effective cross section for double parton scattering in proton–proton collisions is presented. The main goal is the analytic evaluation of the dependence of the effective cross section on the longitudinal momenta of the involved partons, obtained within the holographic Soft-Wall model. If measured in high-energy processes at hadron colliders, this momentum dependence could open a new window on 2-parton correlations in a proton.

Abstract Generalized parton distributions are investigated within a holographic approach where the string modes in the fifth dimension describe the nucleon in a bottom–up or AdS/QCD framework. The aim is to bring the AdS/QCD results in the realm of phenomenology in order to extract consequences and previsions. Two main aspects are studied: (i) the role of the confining potential needed for breaking conformal invariance and introducing confinement (both: classic soft-wall and recent infra-red potentials are investigated); (ii) the extension of the predicted GPDs to the entire range of off-forward kinematics by means of double distributions. Higher Fock states are included describing the nucleon as a superposition of three valence quarks and quark–antiquark pairs and gluons.

We present a calculation of the effective cross section σeff, an important ingredient in the description of double parton scattering in proton–proton collisions. Our theoretical approach makes use of a Light-Front quark model as a framework to calculate the double parton distribution functions at low-resolution scale. QCD evolution is implemented to reach the experimental scale. The obtained values of σeff in the valence region are consistent with the present experimental scenario, in particular with the sets of data which include the same kinematical range. However the result of the complete calculation shows a dependence of σeff on xi, a feature not easily seen in the available data, probably because of their low accuracy. Measurements of σeff in restricted xi regions are addressed to obtain indications on double parton correlations, a novel and interesting aspect of the three dimensional structure of the nucleon.

Recensiamo il libro Philip Roth, Nemeses 2006-2010 – Everyman, Indignation, The Humbling, Neme- sis, Edited by Ross Miller, The Library of America, New York, 2013.

Recensiamo il libro Roth, Philip. Novels 2001-2007 – The Dying Animal, The Plot Against America, Exit Ghost. Edited by Ross Miller. New York: The Library of America, 2013. Stampa.

Review of DeLillo, Don. The Angel Esmeralda. Nine Stories. New York: Scribner, 2011. Print.

Recensiamo il libro Henry James, Novels 1903-1911 – The Ambassadors, The Golden Bowl, The Outcry. Ed. Ross Posnock. New York: The Library of America, 2011.

Review of Philip Roth. The American Trilogy – American Pastoral, I Married a Comunist, The Human Stain, edited by R. Miller. New York: The Library of America, 2011.