skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Status of Flavor Physics

Abstract

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, as are recent discoveries in charm spectroscopy.

Authors:
 [1]
  1. Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)
Publication Date:
OSTI Identifier:
21056788
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 892; Journal Issue: 1; Conference: QCHS7: 7. conference on quark confinement and the hadron spectrum, Ponta Delgada, Acores (Portugal), 2-7 Sep 2006; Other Information: DOI: 10.1063/1.2714354; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BARYON SPECTROSCOPY; C QUARKS; CERN LHC; CP INVARIANCE; FLAVOR MODEL; FORM FACTORS; LATTICE FIELD THEORY; LIFETIME; MESON SPECTROSCOPY; POTENTIALS; QUANTUM CHROMODYNAMICS; SEMILEPTONIC DECAY; SENSITIVITY; STANDARD MODEL

Citation Formats

Shipsey, Ian. Status of Flavor Physics. United States: N. p., 2007. Web. doi:10.1063/1.2714354.
Shipsey, Ian. Status of Flavor Physics. United States. doi:10.1063/1.2714354.
Shipsey, Ian. Tue . "Status of Flavor Physics". United States. doi:10.1063/1.2714354.
@article{osti_21056788,
title = {Status of Flavor Physics},
author = {Shipsey, Ian},
abstractNote = {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, as are recent discoveries in charm spectroscopy.},
doi = {10.1063/1.2714354},
journal = {AIP Conference Proceedings},
number = 1,
volume = 892,
place = {United States},
year = {Tue Feb 27 00:00:00 EST 2007},
month = {Tue Feb 27 00:00:00 EST 2007}
}
  • Many extensions of the standard model (SM) generate contributions to flavor changing neutral current (FCNC) processes that must have sufficient flavor suppression to be consistent with experiments, if the new physics (NP) is associated with a scale of a TeV. Here we present a mechanism for suppressing the NP effects to FCNC processes while allowing for new non-SM CP violating phases. We consider the possibility that the source of NP contributions to FCNC processes share the same flavor symmetry underlying the SM source of FCNC processes which are the quark and lepton mass matrices. We call this the principle ofmore » shared flavor symmetry. In the flavor symmetric limit, the quark and lepton mixing matrices have fixed forms and there are no NP FCNC processes. In the flavor symmetric limit, we take the quark mixing matrix to be the identity matrix and the lepton mixing matrix to be given by tri-bimaximal mixing. Realistic mixing matrices are obtained by the small breaking of the flavor symmetry. New contributions to FCNC processes arise because of nonuniversal breaking of the flavor symmetry in the quark and lepton mass matrices and the NP sources of FCNC processes. In particular, we will focus on new FCNC effects that arise due to the breaking of flavor symmetry only in the quark and charged lepton mass matrices but not in the NP sector. In this scenario, NP contributions to FCNC processes are linked to the source of flavor symmetry breaking in the quark and charged lepton mass matrices. The breaking of flavor symmetry in the NP sector is assumed to produce FCNC effects that are at most the size of NP FCNC effects due to the breaking of flavor symmetry in the quark and charged lepton mass matrices. To demonstrate the mechanism we use a two Higgs doublet model as an example of beyond the SM physics though one should be able to adapt this mechanism to other models of new physics.« less
  • Cited by 5
  • Here, the LHC phenomenology of a low-scale gauged flavor symmetry model with inverted hierarchy is studied, through introduction of a simplified model of broken flavor symmetry. A new scalar (a flavon) and a new neutral top-philic massive gauge boson emerge with mass in the TeV range, along with a new heavy fermion associated with the standard model top quark. After checking constraints from electroweak precision observables, we investigate the influence of the model on Higgs boson physics, notably on its production cross section and decay branching fractions. Limits on the flavon φ from heavy Higgs boson searches at the LHCmore » at 7 and 8 TeV are presented. The branching fractions of the flavon are computed as a function of the flavon mass and the Higgs-flavon mixing angle. We also explore possible discovery of the flavon at 14 TeV, particularly via the φ → Z 0Z 0 decay channel in the 2ℓ2ℓ' final state, and through standard model Higgs boson pair production φ → hh in the b¯bγγ final state. We conclude that the flavon mass range up to 500 GeV could be probed down to quite small values of the Higgs-flavon mixing angle with 100 fb –1 of integrated luminosity at 14 TeV.« less
  • In this study, we present a review of heavy flavor physics results from the CDF and DØ Collaborations operating at the Fermilab Tevatron Collider. A summary of results from Run 1 is included, but we concentrate on legacy results of charm and b physics from Run 2, including results up to Summer 2014.
  • Two of the outstanding discrepancies between weak interaction phenomenology and the standard model come in the large size of the {Delta}{ital I}=1/2 enhancement in {ital K} decays and in the small value of the {ital B} semileptonic branching ratio. We argue that these discrepancies are naturally explained by chromomagnetic dipole operators arising from new physics at the TeV scale. These operators are closely connected to diagrams which contribute to the quark mass matrix, and we show how the proper enhancement of the hadronic decays of {ital s} and {ital b} quarks can be linked to a generation of particular Cabibbo-Kobayashi-Maskawamore » mixing angles or quark masses. We confirm our model-independent analysis with detailed consideration of supersymmetric models and of technicolor models with techniscalars. This picture has additional phenomenological predictions for the {ital B} system: The branching ratio of charmless nonleptonic {ital B} decays should be of order 20%, due to a larger rate for {ital b}{r_arrow}{ital sg}, while there are no dangerous new contributions to {ital b}{r_arrow}{ital s}{gamma}. Sizable contributions to {ital b}{r_arrow}{ital d}{gamma} are a common feature of models incorporating this mechanism. In techniscalar models the {ital Zb}{sub {ital L}}{ital {bar b}}{sub {ital L}} coupling is enhanced, in association with sizable contributions to {ital b}{r_arrow}{ital s}{mu}{sup +}{mu}{sup {minus}}.« less