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Title: New vector-like fermions and flavor physics

We study renormalizable extensions of the standard model that contain vector-like fermions in a (single) complex representation of the standard model gauge group. There are 11 models where the vector-like fermions Yukawa couple to the standard model fermions via the Higgs field. These models do not introduce additional fine-tunings. They can lead to, and are constrained by, a number of different flavor-changing processes involving leptons and quarks, as well as direct searches. An interesting feature of the models with strongly interacting vector-like fermions is that constraints from neutral meson mixings (apart from CP violation in $$ {K}^0-{\overline{K}}^0 $$ mixing) are not sensitive to higher scales than other flavor-changing neutral-current processes. We identify order 1/(4πM) 2 (where M is the vector-like fermion mass) one-loop contributions to the coefficients of the four-quark operators for meson mixing, that are not suppressed by standard model quark masses and/or mixing angles.
 [1] ;  [2] ;  [3]
  1. Kanazawa University (Japan). Institute for Theoretical Physics
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. California Inst. of Technology (CalTech), Pasadena, CA (United States). Walter Burke Institute for Theoretical Physics
Publication Date:
Grant/Contract Number:
AC02-05CH11231; SC0011632
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2015; Journal Issue: 10; Journal ID: ISSN 1029-8479
Springer Berlin
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Beyond Standard Model; Rare decays; B-Physics; CP violation
OSTI Identifier: