epsilon'/epsilon Computation -- Long-distance Evolution

P. H. Soldan

Home/Archive/arXiv

arXiv · hep-ph/9608281

epsilon'/epsilon Computation -- Long-distance Evolution

P. H. Soldan

View original source ↗Read source document ↗Export metadata ↓

Abstract

We present a status report on our study of long-distance contributions to the decay amplitudes A(K^0 --> pi pi, I) in the framework of the 1/N expansion. We argue that a modified prescription for the identification of meson momenta in the chiral loop corrections has to be used to gain a self-consistent picture which allows an appropriate matching with the short-distance part. Possible uncertainties in the analysis of the density-density operators Q_6 and Q_8 which dominate the CP violation parameter epsilon'/epsilon are discussed. As a first result we present the long-distance 1/N correction to the gluon penguin operator Q_6 in the chiral limit.

Explore related subjects

hep-ph

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

P. H. Soldan. 1996-08-09. epsilon'/epsilon Computation -- Long-distance Evolution. https://arxiv.org/abs/hep-ph/9608281

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Precision tests of third-generation four-quark operators: $gg \to h$ and $h \to γγ$

We compute the two-loop contributions to Higgs production via gluon-gluon fusion ($gg \to h$) and Higgs decay into two photons ($h \to γγ$), arising from third-generation four-quark operators in the Standard Model effective field theory (SMEFT). Our analysis is performed in the broken phase of the theory, retaining the full dependence on the Higgs and heavy-quark masses. This includes both finite matching corrections and logarithmic effects stemming from the renormalization group evolution within the SMEFT. As a byproduct, two-loop anomalous dimensions in the SMEFT are obtained. We also briefly discuss the phenomenological implications of our two-loop calculations.

hep-ph↗

arXiv2026

Quantum Sensing Radiative Decays of Neutrinos and Dark Matter Particles

We explore a novel strategy for detecting the radiative decay of very weakly interacting particles by leveraging the extreme sensitivity of quantum devices, such as superconducting transmon qubits and trapped ion systems, to faint electromagnetic signals. By modeling the effective electric field induced by the decay photons, we evaluate the response of quantum sensors across two particle physics scenarios: the cosmic neutrino background and two-component dark matter. We assess the discovery potential of these devices and outline the parameter space accessible under current experimental capabilities. Our analysis demonstrates that quantum sensors can probe radiative decays of dark matter candidates using existing technology, while probing neutrino magnetic moments beyond current limits will require scalable quantum architectures with collective enhancement.

hep-ph↗

arXiv2026

The $\sin(2ϕ)$ azimuthal asymmetry in exclusive $π^0$ production

The $\sin(2ϕ)$ azimuthal angular correlation between the transverse momenta of the scattered electron and the recoil proton in the $ep\to e^\prime p^\prime π^0$ process provides a probe for quark orbital angular momentum. We numerically calculate this asymmetry for the future Electron-Ion Collider (EIC) in the U.S. and China (EicC) kinematics using a light-front quark-scalar-diquark model, in which the light-front wave functions are derived from the soft-wall AdS/QCD framework. We also investigate the properties of the valence quark angular momentum expressed in terms of helicity-independent and helicity-dependent parton distributions. This study aims to establish theoretical constraints on the asymmetry sensitive to the quark orbital angular momentum prior to its first experimental measurement..

hep-ph↗