Flavor physics — Summary and commentary (Exploring the origin of fermion masses, mixing, and CP violation)

1997 ◽  
Vol 59 (1-3) ◽  
pp. 339-346 ◽  
Author(s):  
William J. Marciano
2004 ◽  
Vol 19 (07) ◽  
pp. 497-509 ◽  
Author(s):  
J. SANTIAGO

We review the very stringent lower bounds on the string scale that arise from flavor considerations in models with intersecting branes. Despite the absence of a realistic flavor structure at tree level, flavor changing interactions induce a non-trivial pattern of fermion masses and mixing angles when quantum corrections are taken into account. The resulting realistic theory of flavor allows us to constrain, in an unambiguous way, the string scale up to levels difficult to reconcile non-supersymmetric models.


2020 ◽  
Vol 35 (01) ◽  
pp. 1930018
Author(s):  
Diego Guadagnoli

This paper describes the work pursued in the years 2008–2013 on improving the Standard Model prediction of selected flavor-physics observables. The latter includes: (1) [Formula: see text], that quantifies indirect CP violation in the [Formula: see text] system and (2) the very rare decay [Formula: see text], recently measured at the LHC. Concerning point (1), the paper describes our reappraisal of the long-distance contributions to [Formula: see text],[Formula: see text] that have permitted to unveil a potential tension between CP violation in the [Formula: see text]- and [Formula: see text]-system. Concerning point (2), the paper gives a detailed account of various systematic effects pointed out in Ref. 4 and affecting the Standard Model [Formula: see text] decay rate at the level of 10% — hence large enough to be potentially misinterpreted as nonstandard physics, if not properly included. The paper further describes the multifaceted importance of the [Formula: see text] decays as new physics probes, for instance how they compare with [Formula: see text]-peak observables at LEP, following the effective-theory approach of Ref. 5. Both cases (1) and (2) offer clear examples in which the pursuit of precision in Standard Model predictions offered potential avenues to discovery. Finally, this paper describes the impact of the above results on the literature, and what is the further progress to be expected on these and related observables.


2006 ◽  
Vol 21 (27) ◽  
pp. 5381-5403 ◽  
Author(s):  
Ian Shipsey

The role of charm in testing the Standard Model description of quark mixing and CP violation through measurements of lifetimes, decay constants and semileptonic form factors is reviewed. Together with Lattice QCD, charm has the potential this decade to maximize the sensitivity of the entire flavor physics program to new physics and pave the way for understanding physics beyond the Standard Model at the LHC in the coming decade. The status of indirect searches for physics beyond the Standard Model through charm mixing, CP-violation and rare decays is also reported.


2008 ◽  
Author(s):  
G. G. Ross ◽  
Pyungwon Ko ◽  
Deog Ki Hong
Keyword(s):  

1989 ◽  
Vol 04 (12) ◽  
pp. 1159-1167
Author(s):  
A. DAVIDSON ◽  
B. MARGOLIS ◽  
J. ROBINSON ◽  
P. VALIN

We consider the hypothesis that (i) mv≃0 because the neutrino is SU (3)c× U (1) e.m. neutral, (ii) m electron = 0 at the isospin limit where mu=md, and (iii) all first-generation fer-mions turn massless as αc, α e.m. →0. This hypothesis is supported by the empirical Abraham-Lorentz-type mass formula m=(ζ1Q+ζ2B)2, whose quadratic structure is attributed to a universal seesaw mechanism. We demonstrate how such a formula can stay exact even when switching on the inter-generational mixings. We present a complete model with the above features which gives quark and lepton masses and the K-M matrix, including CP violation.


2015 ◽  
Vol 30 (15) ◽  
pp. 1540013 ◽  
Author(s):  
Gero von Gersdorff

We review constraints from quark and lepton flavor violation on extra dimensional models with warped geometry, both in the minimal and the custodial model. For both scenarios, Kaluza–Klein (KK) masses that are large enough to suppress constraints from electroweak precision tests (EWPT) also sufficiently suppress all quark flavor and CP violation, with the exception of CP violation in [Formula: see text] mixing and (to a lesser extend) in [Formula: see text] mixing. In the lepton sector the minimal scenario leads to excessively large contributions to μ→eγ transitions, requiring KK masses of at least 20 TeV or larger.


1998 ◽  
Vol 13 (29) ◽  
pp. 5037-5074 ◽  
Author(s):  
C. D. FROGGATT ◽  
M. GIBSON ◽  
H. B. NIELSEN ◽  
D. J. SMITH

The fermion masses and mixing angles are fitted using only three free parameters in a nonsupersymmetric extension of the Standard Model, with new, approximately conserved chiral gauge quantum numbers broken by a set of Higgs fields. The fundamental mass scale of this anti-grand-unification model is given by the Planck mass. We also calculate neutrino mixing angles and masses, as well as CP violation from the CKM matrix. A good fit to the observed fermion masses is obtained, but our predictions of the neutrino masses are too small to lead to any observable neutrino oscillation effects claimed today, without introducing another mass scale. We also give some arguments in support of this type of model based on the observed fermion masses.


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