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Related papers: Clearing up the Strong $CP$ problem

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These lecture notes provide a self-contained, graduate-level introduction to the strong $CP$ problem and QCD axion physics from an effective field theory (EFT) viewpoint. We review the construction of the chiral EFT of QCD yielding a…

High Energy Physics - Phenomenology · Physics 2026-02-05 Francesco Sannino

The infamous strong CP problem in particle physics can in principle be solved by a massless up quark. In particular, it was hypothesized that topological effects could substantially contribute to the observed nonzero up-quark mass without…

High Energy Physics - Lattice · Physics 2021-03-02 Constantia Alexandrou , Jacob Finkenrath , Lena Funcke , Karl Jansen , Bartosz Kostrzewa , Ferenc Pittler , Carsten Urbach

We suggest a new solution to the strong CP problem. The solution is based on the proper use of the boundary conditions for the QCD generating functional integral. We expand the perturbative boundary conditions to both perturbative and…

High Energy Physics - Phenomenology · Physics 2023-12-19 S. A. Larin

We analyze the neutron electric dipole moment (EDM) in the Minimal Supersymmetric Model with explicit R-parity violating terms. The leading contribution to the EDM occurs at the 2-loop level and is dominated by the chromoelectric dipole…

High Energy Physics - Phenomenology · Physics 2009-09-01 Darwin Chang , We-Fu Chang , Mariana Frank , Wai-Yee Keung

The SUSY CP problem is one of serious problems in construction of realistic supersymmetric standard models. We consider the problem in a framework in which adjoint chiral multiplets are introduced and gauginos have Dirac mass terms induced…

High Energy Physics - Phenomenology · Physics 2008-11-26 Junji Hisano , Minoru Nagai , Tatsuya Naganawa , Masato Senami

We show that models in which the strong $CP$ problem is solved by introducing an axion field with a mass enhanced by non-QCD UV dynamics at a scale $\Lambda_{\rm SI}$ exhibit enhanced sensitivity to external sources of $CP$ violation. In…

High Energy Physics - Phenomenology · Physics 2022-08-05 Ravneet S. Bedi , Tony Gherghetta , Maxim Pospelov

We discuss composite UV completions of the Nelson-Barr(NB) solution to the strong CP problem. In our construction, the CP symmetry is broken spontaneously by the dynamics of a hidden QCD at $\theta=\pi$. We focus on the minimal…

High Energy Physics - Phenomenology · Physics 2021-03-17 Gilad Perez , Aviv Shalit

We propose a minimal modification of the standard model, remarkable in its simplicity, which may solve the strong CP problem. It employs three Higgs doublets with interactions taken to be invariant under a flavor symmetry. Both CP and the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Sheldon Lee Glashow

The fundamental particle theory called Quantum Chromodynamics (QCD) dictates everything about protons and neutrons, from their intrinsic properties to interactions that bind them into atomic nuclei. Quantities that cannot be fully resolved…

We review the status of the electric dipole moment (EDM) of neutron in the Standard Model (SM). The contributions of the strong and electroweak interactions are discussed seperately. In each case the structure of the Lagrangian and the…

High Energy Physics - Phenomenology · Physics 2009-09-25 Shahida Dar

We describe the finite volume effects of CP-odd quantities, such as the neutron electric dipole moment and the anapole moment in the $\theta$-vacuum, under different topological sectors. We evaluate the three-point Green's functions for the…

High Energy Physics - Phenomenology · Physics 2014-11-18 Keh-Fei Liu

Nucleon electric dipole moments originating from strong CP-violation are being calculated by several groups using lattice QCD. We revisit the finite volume corrections to the CP-odd nucleon matrix elements of the electromagnetic current,…

High Energy Physics - Phenomenology · Physics 2014-07-25 Tarik Akan , Feng-Kun Guo , Ulf-G. Meißner

We present a new class of models which produce zero theta (QCD} angle at the tree and one-loop level due to hermiticity of sub-blocks in the extended quark mass matrices. The structure can be maintained typically by non-abelian generation…

High Energy Physics - Phenomenology · Physics 2009-09-01 Darwin Chang , Wai-Yee Keung

Relativistic many-body methods at different levels of approximations are employed to gain insights into the passage of the electron correlations from lower to higher levels in the accurate determination of the electric dipole polarizability…

Atomic Physics · Physics 2015-03-18 Yashpal Singh , B. K. Sahoo

We propose a novel solution to the Strong CP problem -- to explain why SU(3) strong force has a nearly zero theta angle $\bar\theta_3 \simeq 0$ for the 4d Standard Model (SM). The new ingredient is Symmetric Mass Generation (SMG):…

High Energy Physics - Phenomenology · Physics 2023-01-20 Juven Wang

Electric dipole moments (EDMs) of nucleons and nuclei are actively considered as direct evidence of the CP violation. Calculations of nucleon EDMs on lattice are required to connect the quark- and hadron- level effective CP violating…

High Energy Physics - Lattice · Physics 2020-04-23 Taku Izubuchi , Hiroshi Ohki , Sergey Syritsyn

This study proposes that the longstanding problems of quantum chromodynamics (QCD) as an SU(3)_C gauge theory, the confinement mechanism and \Theta vacuum, can be resolved by dynamical spontaneous symmetry breaking (DSSB) through the…

High Energy Physics - Theory · Physics 2016-09-06 Heui-Seol Roh

We exhibit a novel solution of the strong CP problem, which does not involve any massless particles. The low energy effective Lagrangian of our model involves a discrete spacetime independent axion field which can be thought of as a…

High Energy Physics - Theory · Physics 2009-09-15 Tom Banks , Michael Dine , Nathan Seiberg

The question of CP violating phases in supersymmetry and electric dipole moments (EDMs) is considered within the framework of supergravity grand unification (GUT) models with a light ($\stackrel{<}{\sim}$1 TeV) mass spectrum. In the minimal…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. Accomando , R. Arnowitt , B. Dutta

This work is devoted to the study of the CP-breaking dynamics in QCD, at finite theta-angle. By working in the semi-classical limit, in which the topology of the vacuum is clustered around instantons and anti-instantons, we show that…

High Energy Physics - Phenomenology · Physics 2009-11-10 Pietro Faccioli