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New Vector-Like Fermions and Flavor Physics

Ishiwata, Koji and Ligeti, Zoltan and Wise, Mark B. (2015) New Vector-Like Fermions and Flavor Physics. Journal of High Energy Physics, 2015 (10). Art. No. 027. ISSN 1126-6708. doi:10.1007/JHEP10(2015)027.

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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–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.

Item Type:Article
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URLURL TypeDescription Paper DOIArticle
Ligeti, Zoltan0000-0002-4830-5773
Additional Information:© 2015 The Authors. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. Article funded by SCOAP3. Received: June 25, 2015; Revised: August 31, 2015; Accepted: September 13, 2015; Published: October 6, 2015. We thank Doug Bryman, Tim Gershon, Yossi Nir, Karim Trabelsi, and Phill Urquijo for helpful comments. MBW thanks the Perimeter Institute for their hospitality during the completion of this work. ZL thanks the hospitality of the Aspen Center for Physics, supported by the NSF Grant No. PHY-1066293, during the completion of this work. ZL was supported in part by the Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under contract DE-AC02-05CH11231. MBW was supported by the Gordon and Betty Moore Foundation through Grant No. 776 to the Caltech Moore Center for Theoretical Cosmology and Physics, and by the DOE Grant DE-SC0011632. He is also grateful for the support provided by the Walter Burke Institute for Theoretical Physics.
Group:Walter Burke Institute for Theoretical Physics, Moore Center for Theoretical Cosmology and Physics
Funding AgencyGrant Number
Department of Energy (DOE)DE-AC02-05CH11231
Gordon and Betty Moore Foundation776
Department of Energy (DOE)DE-SC0011632
Walter Burke Institute for Theoretical Physics, CaltechUNSPECIFIED
Subject Keywords:Beyond Standard Model, Rare Decays, B-Physics, CP violation
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Issue or Number:10
Record Number:CaltechAUTHORS:20150812-194949578
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59473
Deposited By: Joy Painter
Deposited On:13 Aug 2015 14:54
Last Modified:10 Nov 2021 22:21

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