52 research outputs found
Possible Effects of Noncommutative Geometry on Weak CP Violation and Unitarity Triangles
Possible effects of noncommutative geometry on weak CP violation and
unitarity triangles are discussed by taking account of a simple version of the
momentum-dependent quark mixing matrix in the noncommutative standard model. In
particular, we calculate nine rephasing invariants of CP violation and
illustrate the noncommutative CP-violating effect in a couple of charged
D-meson decays. We also show how inner angles of the deformed unitarity
triangles are related to CP-violating asymmetries in some typical B_d and B_s
transitions into CP eigenstates. B-meson factories are expected to help probe
or constrain noncommutative geometry at low energies in the near future.Comment: RexTev 16 pages. Modifications made. References added. Accepted for
publication in Phys. Rev.
Review of the Phenomenology of Noncommutative Geometry
We present a pedagogical review of particle physics models that are based on
the noncommutativity of space-time, , with specific attention to the phenomenology these models predict in
particle experiments either in existence or under development. We summarize
results obtained for high energy scattering such as would occur for example in
a future linear collider with , as well as low
energy experiments such as those pertaining to elementary electric dipole
moments and other \cpviolng observables, and finally comment on the status of
phenomenological work in cosmology and extra dimensions.Comment: updated, references added, corrected typo
The noncommutative effects on the dipole moments of fermions in the standard model
We study the dipole moments, electric dipole moment, weak electric dipole
moment, anomalous magnetic moment, anomalous weak magnetic moment, of fermions
in the noncommutative extension of the SM. We observe that the noncommutative
effects are among the possible candidates to explain the electric and weak
electric dipole moment of fermions. Furthermore, the upper bounds for the
parameters which carry space-time and space-space noncommutativity can be
obtained by using the theoretical and experimental results of the fermion
dipole moments.Comment: 15 pages, 8 Figure
The Z--> l^+ l^- and W--> nu_l l^+ decays in the noncommutative standard model}}
We study Z--> l^+ l^- and W--> nu_l l^+ decays in the standard model
including the noncommutative effects. We observe that these effects appear in
the flavor dependent part of the decay widths of the processes under
consideration and therefore, they are more effective for the heavy lepton
decays.Comment: 8 pages, 5 Figure
Heavy Flavour Physics Theory and Experimental Results in Heavy Quark Physics
This book provides a thorough introduction to the phenomenology of heavy flavour physics, those working on the B-factories, LHCb, BTeV, HERA and the Tevatron. It explains how heavy quark theory could be implemented on the lattice, and discusses the status of CP-violation in the neutral kaon system
Geometric aspects of gauge and spacetime symmetries
We investigate several problems in relativity and particle physics where symmetries play a central role; in all cases geometric properties of Lie groups and their quotients are related to physical effects. The first part is concerned with symmetries in gravity. We apply the theory of Lie group deformations to isometry groups of exact solutions in general relativity, relating the algebraic properties of these groups to physical properties of the spacetimes. We then make group deformation local, generalising deformed special relativity (DSR) by describing gravity as a gauge theory of the de Sitter group. We find that in our construction Minkowski space has a connection with torsion; physical effects of torsion seem to rule out the proposed framework as a viable theory. A third chapter discusses a formulation of gravity as a topological BF theory with added linear constraints that reduce the symmetries of the topological theory to those of general relativity. We discretise our constructions and compare to a similar construction by Plebanski which uses quadratic constraints. In the second part we study CP violation in the electroweak sector of the standard model and certain extensions of it. We quantify fine-tuning in the observed magnitude of CP violation by determining a natural measure on the space of CKM matrices, a double quotient of SU(3), introducing different possible choices and comparing their predictions for CP violation. While one generically faces a fine-tuning problem, in the standard model the problem is removed by a measure that incorporates the observed quark masses, which suggests a close relation between a mass hierarchy and suppression of CP violation. Going beyond the standard model by adding a left-right symmetry spoils the result, leaving us to conclude that such additional symmetries appear less natural
Heavy Flavour Physics Theory and Experimental Results in Heavy Quark Physics
This book provides a thorough introduction to the phenomenology of heavy flavour physics, those working on the B-factories, LHCb, BTeV, HERA and the Tevatron. It explains how heavy quark theory could be implemented on the lattice, and discusses the status of CP-violation in the neutral kaon system
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