1,721,050 research outputs found
Guido Altarelli
No full textIn this article we review the life and work of Guido Altarelli (1941–2015)
Guido Altarelli and the evolution of QCD
Full text linkI describe the contributions of Guido Altarelli to the development of Quantum Chromodynamics from the discovery of asymptotic freedom until the end of the Sp¯ pS collider era, 1973–1985
Historical and personal recollections of Guido Altarelli
No full textIn this paper I will present a short scientific biography of Guido Altarelli, briefly describing some of his most important seminal works. I will analyze in great details the paper of the q2 evolution of the effective quark distribution: I will put this paper in a historical perspective, describing our theoretical understanding at that time and the reasons why the paper was so successful
SU(5) Grand Unification in Extra Dimensions and Proton Decay
No full textWe analyse proton decay in the context of simple supersymmetric SU(5) grand unified models with an extra compact spatial dimension described by the orbifold S^1/(Z_2 x Z_2'). Gauge and Higgs degrees of freedom live in the bulk, while matter fields can only live at the fixed point branes. We present an extended discussion of matter interactions on the brane. We show that proton decay is naturally suppressed or even forbidden by suitable implementations of the parity symmetries on the brane. The corresponding mechanism does not affect the SU(5) description of fermion masses also including the neutrino sector, where Majorana mass terms remain allowed.We analyse proton decay in the context of simple supersymmetric SU (5) grand unified models with an extra compact spatial dimension described by the orbifold S 1 /( Z 2 × Z 2 ′). Gauge and Higgs degrees of freedom live in the bulk, while matter fields can only live at the fixed point branes. We present an extended discussion of matter interactions on the brane. We show that proton decay is naturally suppressed or even forbidden by suitable implementations of the parity symmetries on the brane. The corresponding mechanism does not affect the SU (5) description of fermion masses also including the neutrino sector, where Majorana mass terms remain allowed
A Simple Grand Unification View of Neutrino Mixing and Fermion Mass Matrices
No full textAssuming three light neutrinos and the see-saw mechanism we present a semiquantitative model of fermion masses based on (SUSY) SU(5) and abelian horizontal charges. A good description of the observed pattern of quark and lepton masses is obtained. For neutrinos we naturally obtain widely split masses and large atmospheric neutrino mixing as a consequence of SU(5)-related asymmetric mass matrices for d quarks and charged leptons
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