Archive ouverte UNIGE | last documents for author 'Marti Ruiz-Altaba'https://archive-ouverte.unige.ch/Latest objects deposited in the Archive ouverte UNIGE for author 'Marti Ruiz-Altaba'engNucleon structure functions from high energy neutrino interactionshttps://archive-ouverte.unige.ch/unige:137033https://archive-ouverte.unige.ch/unige:137033Structure functions obtained from high energy neutrino and antineutrino scattering from an iron target are presented. These were extracted from the combined data of Fermilab experiments E616 and E701; these utilized narrow band beam runs between 1979–1982. The structure functions are used to test the validity of quarkparton model (QPM) predictions and to extract the QCD scale parameter Λ from fits to the Altarelli-Parisi equations.Fri, 12 Jun 2020 14:34:00 +0200New solutions to the Yang-Baxter equation from two-dimensional representations of Uq(sl(2)) at roots of unityhttps://archive-ouverte.unige.ch/unige:115694https://archive-ouverte.unige.ch/unige:115694We present particularly simple new solutions to the Yang-Baxter equation arising from two-dimensional cyclic representations of quantum SU(2). They are readily interpreted as scattering matrices of relativistic objects, and the quantum group becomes a dynamical symmetry.Wed, 03 Apr 2019 12:45:55 +0200The Stueckelberg Fieldhttps://archive-ouverte.unige.ch/unige:85283https://archive-ouverte.unige.ch/unige:85283In 1938, Stueckelberg introduced a scalar field which makes an Abelian gauge theory massive but preserves gauge invariance. The Stueckelberg mechanism is the introduction of new fields to reveal a symmetry of a gauge--fixed theory. We first review the Stueckelberg mechanism in the massive Abelian gauge theory. We then extend this idea to the standard model, stueckelberging the hypercharge U(1) and thus giving a mass to the physical photon. This introduces an infrared regulator for the photon in the standard electroweak theory, along with a modification of the weak mixing angle accompanied by a plethora of new effects. Notably, neutrinos couple to the photon and charged leptons have also a pseudo-vector coupling. Finally, we review the historical influence of Stueckelberg's 1938 idea, which led to applications in many areas not anticipated by the author, such as strings. We describe the numerous proposals to generalize the Stueckelberg trick to the non-Abelian case with the aim to find alternatives to the standard model. Nevertheless, the Higgs mechanism in spontaneous symmetry breaking remains the only presently known way to give masses to non-Abelian vector fields in a renormalizable and unitary theory.Thu, 14 Jul 2016 14:04:41 +0200