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Related papers: Nelson-Barr Models with Vector-Like Quark Doublets

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In this article, we present a very general but not ultimate solution of CPV problem in the standard model. Our study starts from a naturally Hermitian ${\bf M^2}\equiv M^q \cdot M^{q\dagger}$ rather than the previously assumed Hermitian…

High Energy Physics - Phenomenology · Physics 2022-05-25 Chilong Lin

The strong CP violation problem has a long history emanating from its discovery 60 years ago in the decay of neutral kaons and subsequent experimental and theoretical studies over several decades. We review herein experimental data that…

High Energy Physics - Phenomenology · Physics 2024-12-02 Nicolai Popov , William J. Briscoe , Igor Strakovsky

We argue that the $t \bar t$ production asymmetry observed at the tevatron might be simply explained if the standard $SU(3)_c$ QCD theory is extended to $SU(N_c)$ which is spontaneously broken at a scale just above the weak scale. The…

High Energy Physics - Phenomenology · Physics 2013-02-14 R. Foot

In this talk I will show that the two-Higgs doublet model with vacuum CP violation and approximate global $U(1)$ family symmetries may provide one of the simplest and most attractive models for understanding the origin and mechanisms of CP…

High Energy Physics - Phenomenology · Physics 2009-10-28 Yue-Liang Wu

We present a solution to the strong CP problem based on spontaneous CP violation and discrete family symmetries. The model predicts in a natural way the almost right-angled quark unitarity triangle angle ($\alpha \simeq 90^\circ$) by making…

High Energy Physics - Phenomenology · Physics 2013-11-27 Stefan Antusch , Martin Holthausen , Michael A. Schmidt , Martin Spinrath

Recent improvements to the limit of Delta M_{B_s} imply that pure superweak theories, while not excluded, no longer provide a good fit to the data. A class of general superweak theories is introduced in which all flavor changing…

High Energy Physics - Phenomenology · Physics 2009-10-30 Riccardo Barbieri , Lawrence Hall , Achille Stocchi , Neal Weiner

The effect of spontaneous breaking of chiral symmetry over the spectrum of highly excited hadrons is addressed in the framework of a microscopic chiral potential quark model (Generalised Nambu-Jona-Lasinio model) with a vectorial…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yu. S. Kalashnikova , A. V. Nefediev , J. E. F. T. Ribeiro

The model of the neutrino mass matrix which we proposed in 2000 is revisited in the light of the recent T2K experiments. This model has the special property that it predicts the maximal 2-3 mixing and CP violation under the some simple…

High Energy Physics - Phenomenology · Physics 2015-11-18 Eiichi Takasugi

We consider the generation of a baryon asymmetry in an extension of the Standard Model with two singlet Majorana fermions that are degenerate above the electroweak phase transition. The model can explain neutrino masses as well as the…

High Energy Physics - Phenomenology · Physics 2023-11-30 S. Sandner , P. Hernandez , J. Lopez-Pavon , N. Rius

We examine nonrenormalizable Lorentz- and CPT-violating effective operators applied to the quark sector of the Standard Model. Using Drell-Yan events collected by the ATLAS and CMS Collaborations, several constraints are extracted from…

High Energy Physics - Phenomenology · Physics 2024-12-20 Enrico Lunghi , Nathaniel Sherrill

We review the theory and phenomenology of isosinglet vector-like quarks (VLQs). In recent years, interest in VLQs has been increasing, due to their contributions to new physics effects that can be tested in experiments at LHC and…

High Energy Physics - Phenomenology · Physics 2024-01-23 João M. Alves , G. C. Branco , A. L. Cherchiglia , C. C. Nishi , J. T. Penedo , Pedro M. F. Pereira , M. N. Rebelo , J. I. Silva-Marcos

Supersymmetric extensions to the standard model provide viable dark matter candidates, and can introduce additional charge-parity (CP) violation, needed for obtaining the observed baryon asymmetry of the universe. We study the possibilities…

High Energy Physics - Phenomenology · Physics 2013-04-09 Katri Huitu , Jari Laamanen , Lasse Leinonen , Santosh Kumar Rai , Timo Rüppell

We revisit the supersymmetric CP problem and find that it can be naturally resolved if the origin of CP violation is closely related to the origin of flavour structures. In this case, the supersymmetry breaking dynamics do not bring in any…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Abel , D. Bailin , S. Khalil , O. Lebedev

Recently, the D0 collaboration reported a large CP violation in the same-sign dimuon charge asymmetry which has the $3.2 \sigma$ deviation from the value estimated in the Standard Model. In this paper, several new physics models are…

High Energy Physics - Phenomenology · Physics 2011-02-18 Jihn E. Kim , Min-Seok Seo , Seodong Shin

We discuss CP-violation in a model with a real and a complex isospin triplet Higgs fields without introducing any symmetries except for the electroweak gauge symmetry. This corresponds to the minimal extension of the Higgs sector with the…

High Energy Physics - Phenomenology · Physics 2023-06-16 Ting-Kuo Chen , Cheng-Wei Chiang , Kei Yagyu

In the minimal left-right symmetric model with spontaneous CP violation, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors. In addition, the left-and right-handed Majorana…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mu-Chun Chen , K. T. Mahanthappa

We review the present status of CP violating problem in supersymmetric extensions of the standard model. We analyze the constraints imposed by the experimental limits of the electron, neutron, and mercury electric dipole moments on the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Shaaban Khalil

A vector-like extension of the standard model for heavier quarks and leptons with $SU(2)\times U(1)$ gauge symmetry and only one Higgs doublet is examined. This scheme incorporates infinitely many fermions and avoids the appearance of a…

High Energy Physics - Phenomenology · Physics 2017-02-01 Kazuo Fujikawa

It is pointed out that the recent measurement of the angle $\gamma$ of the unitarity triangle, providing irrefutable evidence for a complex Cabibbo-Kobayashi-Maskawa (CKM) matrix, presents a great challenge for supersymmetric models with…

High Energy Physics - Phenomenology · Physics 2010-04-05 G. C. Branco , D. Emmanuel-Costa , J. C. Romao

We show that the Two-Higgs-Doublet Model (2HDM) constrained by the two-loop-order requirement of cancellation of quadratic divergences is consistent with the existing experimental constraints. The model allows to ameliorate the little…

High Energy Physics - Phenomenology · Physics 2015-05-20 Bohdan Grzadkowski , Per Osland