Search arXivSearch

arXiv · hep-ph/0205045

Studying Bounds on Lepton Flavor Violating (LFV) Decay Processes

Abstract

This dissertation reviews the Standard Model formalism as well as the Lepton Flavour Violating (LFV) decay processes which cause its extension, known as the physics beyond the SM. Firstly, using the experimental bounds on three body LFV decays, the corresponding bounds on two body LFV decays are reviewed. The dynamical suppression of three body LFV decays due to momentum dependent couplings is also reviewed. Secondly, the role of the LFV decays to explain the LSND excess is discussed in detail, for which the experimental bounds on three body LFV decays, i.e. μ-> 3e are used to constraint the coupling \tilde{g}_{Z_{μe}}, which is needed to calculate the anomalous muon decay μ-> eν_l\barν_l. Then comparing the effective coupling of anomalous muon decay to r>1.6\times 10^{-3} [9809524], it is proved that LFV is not the correct hypothesis to explain the LSND excess. Finally, LFV decays at loop order are studied in Seesaw model of neutrino masses [PRL. 86 2502 (2001)] where the smallness of the Seesaw neutrino mass may be naturally realized with m_N (mass of right-handed singlet neutrinos) of order 1 TeV. It is shown that the Higgs mass of a new scalar doublet with lepton number L=-1 needed in the model has to be larger than 50 TeV to get the branching ratio of μ-> 3e to be consistent with the existing bound on μ-> 3e. This defeats the original motivation of the model, namely that there is no physics beyond the TeV energy scale.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M. Jamil Aslam. 2002-05-06. Studying Bounds on Lepton Flavor Violating (LFV) Decay Processes. https://arxiv.org/abs/hep-ph/0205045

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

KEEP EXPLORING

Related papers

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

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

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