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Modular symmetry in the SMEFT
Title:  Modular symmetry in the SMEFT 
Authors:  Kobayashi, Tatsuo Browse this author →KAKEN DB  Otsuka, Hajime Browse this author  Tanimoto, Morimitsu Browse this author  Yamamoto, Kei Browse this author 
Issue Date:  1Mar2022 
Publisher:  American Physical Society (APS) 
Journal Title:  Physical Review D 
Volume:  105 
Issue:  5 
Start Page:  055022 
Publisher DOI:  10.1103/PhysRevD.105.055022 
Abstract:  We study the modular symmetric standard model effective field theory. We employ the stringy Ansatz on coupling structure that 4point couplings y((4)) of matter fields are written by a product of 3point couplings y((3)) of matter fields, i.e., y((4)) = y((3))y((3)). In this framework, we discuss the flavor structure of bilinear fermion operators and 4fermion operators, where the holomorphic and antiholomorphic modular forms appear. From the Ansatz, the A(4) modularinvariant semileptonic fourfermion operator [(E) over bar (R)Gamma ER][(D) over bar (R)Gamma DR] does not lead to the flavor changing (FC) processes since this operator would be constructed in terms of gauge couplings g as y((3)) similar to g. The chirality flipped bilinear operator [(D) over bar (R)Gamma DL] also does not lead FC if the mediated mode corresponds to the Higgs boson Hd. In this case, the flavor structure of this operator is the exactly same as the mass matrix. On the other hand, if the flavor structure of the operator is not the exactly same as the mass matrix, the situation would change drastically. Then, we obtain the nontrivial relations of FC transitions at nearby fixed points tau = i, omega, i infinity, which are testable in the future. As an application, we discuss the relations of the lepton flavor violation processes mu > e gamma, tau > mu gamma and tau > e gamma at nearby tau(e) = i, where the successful lepton mass matrix was obtained. We also study the flavor changing 4quark operators in the A(4) modular symmetry of quarks. As a result, the minimal flavor violation could be realized by taking relevant specific parameter sets of order one. 
Type:  article 
URI:  http://hdl.handle.net/2115/85513 
Appears in Collections:  理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peerreviewed Journal Articles, etc)

