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Analyticity and unitarity constrain certain classe of new physics models by linking flavor-conserving and flavor-violating four-fermion interactions. In this work, we explore how these theoretical relations impact flavor-violating rare top…

High Energy Physics - Phenomenology · Physics 2025-09-09 Wolfgang Altmannshofer , Zev Balme , Christopher M. Donohue , Stefania Gori , Siddharth Vignesh Mukundhan

Weak bases of flavors (u, c), (d,s), (e, \mu), (\nu_e,\nu_\mu) are assumed as the S_3 doublet and t, b, \tau, {\nu_\tau} are the S_3 singlet and further there are assumed S_3 doublet Higgs (H_1, H_2) and S_3 singlet Higgs H_S. We suggest an…

High Energy Physics - Phenomenology · Physics 2011-08-08 Tadayuki Teshima , Yoshitaka Okumura

We define a new class of Z' models with neutral flavour-changing interactions at tree level in the down-quark sector. They are related in an exact way to elements of the quark mixing matrix due to an underlying flavoured U(1)' gauge…

High Energy Physics - Phenomenology · Physics 2016-06-30 Martin Jung

We argue that the Nelson-Barr solution to the Strong CP Problem can be naturally realized in an E$_6$ Grand-Unified Theory. The chiral SM fermions reside in three generations of E$_6$ fundamentals together with heavy vectorlike down quarks,…

High Energy Physics - Phenomenology · Physics 2018-12-05 Jakob Schwichtenberg , Paul Tremper , Robert Ziegler

We present an effective theory approach for a model with a left-right symmetric flavour group broken only by the Yukawa couplings. An underlying SU(2)_L x SU(2)_R x U(1)_{B-L} global symmetry is assumed without specifying the fundamental…

High Energy Physics - Phenomenology · Physics 2010-11-25 Katrin Gemmler

Minimal Flavour Violation in its strong or weak versions, based on $U(3)^3$ and $U(2)^3$ respectively, allows suitable extensions of the Standard Model at the TeV scale to comply with current flavour constraints in the quark sector. Here we…

High Energy Physics - Phenomenology · Physics 2016-01-27 Riccardo Barbieri , Fabrizio Senia

In the context of the 2HDM, and assuming that neutrinos acquire masses via the Weinberg operator, we perform a systematic analysis to determine the minimal quark and lepton flavour patterns, compatible with masses, mixing and CP violation…

High Energy Physics - Phenomenology · Physics 2025-12-03 J. R. Rocha , H. B. Câmara , R. G. Felipe , F. R. Joaquim

We have studied two approaches to predict quark and lepton mixing patterns from the same flavor symmetry group in combination with CP symmetry. The first approach is based on the residual symmetry $Z_2$ in the charged lepton sector and…

High Energy Physics - Phenomenology · Physics 2018-09-19 Jun-Nan Lu , Gui-Jun Ding

We review and update the constraints on the parameters of the quark flavour mixing matrix $V_{CKM}$ in the standard model and estimate the resulting CP asymmetries in $B$ decays, taking into account recent experimental and theoretical…

High Energy Physics - Phenomenology · Physics 2010-11-11 A. Ali , D. London

We consider models of maximal flavor violation (MxFV), in which a new scalar mediates large q_3 <-> q_1 or q_3 <-> q_2 flavor changing transitions (q_i is an i'th generation quark), while q_3 <-> q_3 transitions are suppressed, e.g.,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Shaouly Bar-Shalom , Arvind Rajaraman

An approach to solving the Strong CP Problem in supersymmetric theories is discussed which uses abelian family symmetries to align the mass matrices of the quarks and squarks. In this way both the Strong CP Problem and the characteristic…

High Energy Physics - Phenomenology · Physics 2011-05-12 S. M. Barr

The fundamental constraint on two Higgs doublet models comes from the requirement of sufficiently suppressing flavor-changing neutral currents. There are various standard approaches for dealing with this problem, but they all tend to share…

High Energy Physics - Phenomenology · Physics 2011-09-13 Jason Evans , Brian Feldstein , William Klemm , Hitoshi Murayama , Tsutomu T. Yanagida

We explain the many reasons for the interest in flavor physics. We describe flavor physics and the related CP violation within the Standard Model, and explain how the B-factories proved that the Kobayashi-Maskawa mechanism dominates the CP…

High Energy Physics - Phenomenology · Physics 2016-05-03 Y. Nir

We study the CP-violating phase of the quark sector in the $U(8)$ flavor model on $T^2/Z_N \, (N=2,3,4,6)$ with non-vanishing magnetic fluxes, where properties of possible origins of the CP violation are investigated minutely. In this…

High Energy Physics - Theory · Physics 2017-04-18 Tatsuo Kobayashi , Kenji Nishiwaki , Yoshiyuki Tatsuta

Experimental hints for lepton flavor universality violation in beauty-quark decay both in neutral- and charged-current transitions require an extension of the Standard Model for which scalar leptoquarks (LQs) are the prime candidates.…

High Energy Physics - Phenomenology · Physics 2022-09-21 J. Julio , Shaikh Saad , Anil Thapa

We discuss the representations that new scalar degrees of freedom (beyond those in the minimal standard model) can have if they couple to quarks in a way that is consistent with minimal flavor violation. If the new scalars are singlets…

High Energy Physics - Phenomenology · Physics 2014-11-20 Jonathan M. Arnold , Maxim Pospelov , Michael Trott , Mark B. Wise

Updated standard model predictions for $D_{(s)} \to P l^+ l^-$, $l=e,\mu$, $P=\pi,K$ and inclusive decays are presented. Model-independent constraints on $|\Delta C|=|\Delta U|=1$ Wilson coefficients are worked out. New physics (NP)…

High Energy Physics - Phenomenology · Physics 2016-04-06 Stefan de Boer , Gudrun Hiller

Pursuing a bottom-up approach to explore which flavor symmetry could serve as an explanation of the observed fermion masses and mixings, we discuss an extension of the standard model (SM) where the flavor structure for both quarks and…

High Energy Physics - Phenomenology · Physics 2011-05-05 C. Hagedorn , M. Lindner , R. N. Mohapatra

In multi-Higgs-doublet models, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP…

High Energy Physics - Phenomenology · Physics 2011-04-05 Antonio Pich

Current constraints on flavor-changing neutral currents (FCNCs) strongly indicate that any new physics emerging at the 1-10 TeV scale must adhere to the Minimal Flavor Violation (MFV) principle, where Yukawa couplings are the sole sources…

High Energy Physics - Phenomenology · Physics 2025-01-08 A. Carrillo-Monteverde , R. Escorcia Ramírez , S. Gómez-Ávila , L. Lopez-Lozano