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Related papers: Do Minimal Parity Solutions to the Strong CP Probl…

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In the minimal Left-Right model the choice of left-right symmetry is twofold: either generalized parity $\mathcal P$ or charge conjugation $\mathcal C$. In the minimal model with spontaneously broken strict $\mathcal P$, a large tree-level…

High Energy Physics - Phenomenology · Physics 2014-11-11 Alessio Maiezza , Miha Nemevšek

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

It is shown that the minimal supersymmetric left-right model can provide a natural solution to the strong {\it CP} problem without the need for an axion, nor any additional symmetries beyond supersymmetry and parity.

High Energy Physics - Phenomenology · Physics 2009-10-28 Rabindra N. Mohapatra , Andrija Rasin

We construct phenomenologically viable supersymmetric models where CP is an approximate symmetry. The full high energy theory has exact CP and horizontal symmetries that are spontaneously broken with a naturally induced hierarchy of scales,…

High Energy Physics - Phenomenology · Physics 2009-10-31 Galit Eyal , Yosef Nir

This study proposes an explicit construction method for quantum quasi-cyclic low-density parity-check (QC-LDPC) codes with a girth of 12. The proposed method designs parity-check matrices that maximize the girth while maintaining an…

Information Theory · Computer Science 2025-05-06 Daiki Komoto , Kenta Kasai

We propose a novel realization of the Nelson-Barr mechanism "seeded'' by a dark sector containing scalars and vector-like quarks. Charge-parity (CP) and a $\mathcal{Z}_8$ symmetry are spontaneously broken by the complex vacuum expectation…

High Energy Physics - Phenomenology · Physics 2023-11-28 H. B. Câmara , F. R. Joaquim , J. W. F. Valle

Three hard problems! In this talk I investigate the long-distance properties of quantum chromodynamics in the presence of a topological theta term. This is done on the lattice, using the gradient flow to isolate the long-distance modes in…

High Energy Physics - Lattice · Physics 2022-02-01 Gerrit Schierholz

We find that spontaneously broken parity (P) or left-right symmetry stabilizes dark matter in a beautiful way. If dark matter has a non-real intrinsic parity \pm i (e.g. Majorana fermions), parity can ensure that it cannot decay to all…

High Energy Physics - Phenomenology · Physics 2014-02-07 Ravi Kuchimanchi

CP invariance is a very attractive solution to the strong CP problem in QCD. This solution requires the vanishing ${\rm arg}\,[{\rm det}\, M_d\, {\rm det} M_u]$, where the $M_d$ and $M_u$ are the mass matrices for the down- and up-type…

High Energy Physics - Phenomenology · Physics 2025-10-22 Morimitsu Tanimoto , Tsutomu T. Yanagida

We point out a novel possible mechanism by which the electroweak hierarchy problem can be avoided in the (effective) quantum field theory. Assuming the existence of a UV complete underlying fundamental theory and treating the cutoff scale…

High Energy Physics - Phenomenology · Physics 2015-01-14 Piotr H. Chankowski , Adrian Lewandowski , Krzysztof A. Meissner , Hermann Nicolai

We present simple effective theory of quark masses, mixing and CP violation with level $N=3$ ($A_4$) modular symmetry, which provides solution to the strong CP problem without the need for an axion. The vanishing of the strong CP-violating…

High Energy Physics - Phenomenology · Physics 2024-07-03 S. T. Petcov , M. Tanimoto

We propose an alternative to the axion mechanism for addressing the charge parity (CP) problem in quantum chromodynamics (QCD). Our approach involves imposing CP as an inherent symmetry of the Lagrangian, which is then spontaneously broken.…

High Energy Physics - Phenomenology · Physics 2025-10-08 Rodolfo Ferro-Hernandez , Stefano Morisi , Eduardo Peinado

We exhibit a solution to the strong CP problem in which ultraviolet physics renders the QCD theta angle physically unobservable. Our models involve new strong interactions beyond QCD and particles charged under both the new interactions and…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. D. H. Hsu , F. Sannino

We stress that a natural solution of the $\mu$ problem requires two ingredients: a symmetry that would enforce $\mu = 0$ as well as the occurence of a small breaking parameter that generates a nonzero $\mu$. It is suggested that both the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jihn E. Kim , Hans Peter Nilles

The strong CP problem can be solved if the laws of nature are invariant under a space-time parity exchanging the Standard Model with its mirror copy. We review and extend different realizations of this idea with the aim of discussing Dark…

High Energy Physics - Phenomenology · Physics 2023-10-23 Michele Redi , Andrea Tesi

Parity violation in QCD is a consequence of the so-called QCD $\theta$-vacuum. As a result, parity-odd fragmentation functions are introduced and they bring in new observables in the back-to-back dihadron productions in…

High Energy Physics - Phenomenology · Physics 2024-02-07 Yan-Lei Pan , Kai-Bao Chen , Yu-Kun Song , Shu-Yi Wei

It is argued that in the context of supersymmetry, the Strong CP Problem is most naturally seen as an aspect (particularly severe) of the whole complex of flavor-violating and CP-violating problems of supersymmetry. It is shown that certain…

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

We revisit the contribution to the strong CP parameter $\bar \theta$ from leptonic CP violation at one-loop level in the minimal left-right symmetric model in the case of generalized parity as the left-right symmetry. The Hermitian neutrino…

High Energy Physics - Phenomenology · Physics 2024-08-27 Gang Li , Ding-Yi Luo , Xiang Zhao

Quantum Chromodynamics admits a CP-violating contribution to the action, the $\theta$ term, which is expected to give rise to a nonvanishing electric dipole moment of the neutron. Despite intensive search, no CP violations have been found…

High Energy Physics - Phenomenology · Physics 2025-04-07 Gerrit Schierholz

We argue that CP violation has rather dramatic impact on the "gravity as the weakest force" conjecture. Namely we find that new ultraviolet scale must be $\Lambda \lesssim \theta g^3 M_P$, where $\theta$ is an effective parameter describing…

High Energy Physics - Theory · Physics 2008-07-05 Archil Kobakhidze