373 research outputs found
Selected topics on tau physics
The B Factories have generated a large amount of new results on the tau
lepton. The present status of some selected topics on tau physics is presented:
charged-current universality tests, bounds on lepton-flavour violation, the
determination of alpha_s from the inclusive tau hadronic width, and the
measurement of |V_{us}| through the Cabibbo-suppressed decays of the tau
lepton.Comment: Invited talk at the XXXI International Conference of Theoretical
Physics, "Matter to the Deepest", Ustron, Poland, 5-11 September 200
The Standard Model of Electroweak Interactions
Gauge invariance is a powerful tool to determine the dynamical forces among
the fundamental constituents of matter. The particle content, structure and
symmetries of the Standard Model Lagrangian are discussed. Special emphasis is
given to the many phenomenological tests which have established this
theoretical framework as the Standard Theory of the electroweak interactions:
electroweak precision tests, Higgs searches, quark mixing, neutrino
oscillations. The present experimental status is summarized.Comment: Based on lectures given at the 6th CERN-Fermilab Hadron Collider
Physics Summer School (Geneva, 2011), 2010 European School of HEP (Raseborg,
Finland), 2010 Int. School on Astroparticle Physics (Zaragoza, Spain), 2010
IDPASC School (Sesimbra, Portugal) and 2009 Int. Summer School and Conference
on HEP (Mugla, Turkey, 2009). 52 pages, 38 figure
The Standard Model of Particle Physics: Status & Low-Energy Tests
Precision measurements of low-energy observables provide stringent tests of
the Standard Model structure and accurate determinations of its parameters. An
overview of the present experimental status is presented. The main topics
discussed are the muon anomalous magnetic moment, the asymptotic freedom of
strong interactions, the lepton universality of gauge couplings, the quark
flavour structure and CP violation.Comment: 12 pages, 6 Postscript Figure
Flavour Dynamics and Violations of the CP Symmetry
An overview of flavour physics and CP-violating phenomena is presented. The
Standard Model quark-mixing mechanism is discussed in detail and its many
successful experimental tests are summarized. Flavour-changing transitions put
very stringent constraints on new-physics scenarios beyond the Standard Model
framework. Special attention is given to the empirical evidences of CP
violation and their important role in our understanding of flavour dynamics.
The current status of the so-called flavour anomalies is also reviewed.Comment: Invited lectures at the 2017 and 2019 CERN - Latin-American Schools
of High-Energy Physics (San Juan del R\'io, M\'exico, 8-21 March 2017; and
Villa General Belgrano, C\'ordoba Province, Argentina, 13--26 March 2019). 38
pages, 13 figures. Fully updated version (April 2020) with current
experimental and theoretical status. arXiv admin note: substantial text
overlap with arXiv:1112.4094, arXiv:hep-ph/9601202, arXiv:1201.053
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