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Related papers: On the $\uptheta$-vacua and CP violation

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We show that, in perturbative string models where the source of CP violation is a complex vacuum expectation value (v.e.v.) for one or more compactification moduli, CP is conserved if a CP transformation acting on the modulus values is an…

High Energy Physics - Theory · Physics 2007-05-23 Thomas Dent

We propose a mechanism for relaxing a gauge theory CP violating phase in discrete steps to very small values. The idea is that the CP violating phase includes the magnetic dual of a $4$-form flux which can discharge by the nucleation of…

High Energy Physics - Phenomenology · Physics 2026-04-28 Nemanja Kaloper

The absence of a neutron electric dipole moment (EDM) constrains the quantum chromodynamics (QCD) theta angle to be less than one part in ten billion, posing the Strong $CP$ problem. We revisit two classes of proposed solutions. First, we…

High Energy Physics - Phenomenology · Physics 2025-10-23 Joshua N. Benabou , Anson Hook , Claudio Andrea Manzari , Hitoshi Murayama , Benjamin R. Safdi

Quantum field theory has been established on symmetries, but their fundamentality could be limited as practical calculations of physical observations are not based on interacting Lagrangian. The requirement of Lorentz invariance on vacuum…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. C. Yoon

The general production {\it and} decay mechanism of $\ttbar$ in future high-energy $\epem$ colliders has been investigated in a model-independent way, focusing on an observation of possible CP violation. Angular asymmetries sensitive to CP…

High Energy Physics - Phenomenology · Physics 2010-11-01 Bohdan Grzcadkowski

This is a pedagogical review of some selected topics of CP and T violation in the decays of K mesons. Diagonalization of the quark mass matrix and the emergence of the complex phase in both the standard and the left--right symmetric models…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. N. Rogalyov

It is shown that the mechanism of spontaneous symmetry breaking provides not only a mechanism for giving mass to the bosons and the fermions, but also a mechanism for generating CP-phase of the bosons and the fermions. A two-Higgs doublet…

High Energy Physics - Phenomenology · Physics 2008-02-03 Yue-Liang Wu

We identify a fundamental tension between the standard formulation of CP violation and diffeomorphism invariance in general relativity. The effective Hamiltonian approach, while phenomenologically successful, relies on a preferred time…

General Relativity and Quantum Cosmology · Physics 2026-02-17 Alibordi Muhammad

Spontaneous CP violation (SCPV) provides a promising solution to the strong CP problem, explaining the smallness of the QCD $\theta$-angle while generating the Cabibbo-Kobayashi-Maskawa (CKM) phase. In the present work, we review and…

High Energy Physics - Phenomenology · Physics 2026-05-07 Yuichiro Nakai

Simply based on CP arguments, we argue against a Standard Model explanation of the baryon asymmetry of the universe in the presence of a first order phase transition. A CP-asymmetry is found in the reflection coefficients of quarks hitting…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. B. Gavela , P. Hernández , J. Orloff , O. Pène

It is pointed out that any CP violation which may be found in lattice QCD with a chiral phase in the fermion mass term cannot be relevant for the continuum theory. CP is classically conserved in the corresponding continuum theory and is…

High Energy Physics - Lattice · Physics 2007-05-23 P. Mitra

In a physical system with conformal symmetry, observables depend on cross-ratios, measures of distance invariant under global conformal transformations (conformal geometry for short). We identify a quantum information-theoretic mechanism by…

Quantum Physics · Physics 2025-03-19 Isaac H. Kim , Xiang Li , Ting-Chun Lin , John McGreevy , Bowen Shi

The search for a new source of CP violation is one of the most important endeavors in particle physics. A particularly interesting way to perform this search is to probe the CP phase in the $h\tau\tau$ coupling, as the phase is currently…

High Energy Physics - Phenomenology · Physics 2015-05-05 Andrew Askew , Prerit Jaiswal , Takemichi Okui , Harrison B. Prosper , Nobuo Sato

The conservation of $CP$ in QCD has been shown to follow from a careful treatment of the path integral and canonical quantization in arXiv:2001.07152 and arXiv:2403.00747. Here, we refute the critique of these results put forth in…

High Energy Physics - Phenomenology · Physics 2025-11-10 Wen-Yuan Ai , Björn Garbrecht , Carlos Tamarit

On general grounds based on quantum field theory the decay amplitude for $\Sigma^0 \to \Lambda \gamma$ consists of a parity conserving magnetic and a parity violating electric dipole transition moment. Because of the subsequent…

High Energy Physics - Phenomenology · Physics 2018-12-05 Shankar Sunil Nair , Elisabetta Perotti , Stefan Leupold

A shape of the unitary triangle versus a CP violating parameter \delta depends on the phase conventions of the CKM matrix, because the CP violating parameter \delta cannot directly be observed, so that it is not rephasing-invariant. In…

High Energy Physics - Phenomenology · Physics 2014-11-18 Yoshio Koide

Whether self correcting quantum memories can exist at non-zero temperature in a physically reasonable setting remains a great open problem. It has recently been argued [1] that symmetry protected topological (SPT) systems in three space…

Quantum Physics · Physics 2021-06-09 Charles Stahl , Rahul Nandkishore

We argue the possibility that a real part of a flavor neutrino mass matrix only respects a mu-tau symmetry. This possibility is shown to be extended to more general case with a phase parameter \theta, where the mu-tau symmetric part has a…

High Energy Physics - Phenomenology · Physics 2014-11-18 Teruyuki Kitabayashi , Masaki Yasue

An attempt is made to describe from first principles the large-scale structure of the confining vacuum in quantum chromodynamics. Starting from our previous variational studies of the SU(2) pure gauge theory in an external Abelian…

High Energy Physics - Phenomenology · Physics 2024-02-27 Paolo Cea

CP violation is observed to date only in K^0 decays and is parameterizable by a single quantity epsilon. Because it is one of the least understood phenomena in the Standard Model and holds a clue to baryogenesis, it must be investigated…

High Energy Physics - Phenomenology · Physics 2008-11-26 Isard Dunietz