scholarly journals $μ$-$e$ conversion experiments at J-PARC

Author(s):  
Natsuki Teshima

There are two plans of experiments to search for muon to electron (\muμ-ee) conversion at J-PARC, which are called DeeMe and COMET. \muμ-ee conversion is one of the charged lepton flavor violation processes, which are forbidden in the Standard Model, but some theories beyond the Standard Model predict relatively large branching ratios at orders of 10^{-12}10−12 to 10^{-17}10−17. DeeMe will be conducted with a sensitivity of 1\times10^{-13}1×10−13 using a carbon target for 1 year, and COMET will be done with that of 3\times10^{-15}3×10−15 in Phase-I. In this article, the current status of these two experiments will be presented.

2012 ◽  
Vol 27 (40) ◽  
pp. 1250230
Author(s):  
JING YANG ◽  
KE-SHENG SUN

In the minimal supersymmetric extension of the Standard Model (MSSM) the interactions between the SUSY particles and the Standard Model (SM) particles can contribute to the lepton flavor violation (LFV) decays of vector mesons at loop level. Taking the constraint on the lightest Higgs mass around 126 GeV, we study these decays by a scan over the parameter space which gives the predictions on μ-e conversion and τ→μγ satisfying the experimental bounds. The branching ratios of the vector mesons decays into eμ are strongly suppressed. However, the branching ratios of the heavy flavor mesons decays into τμ can reach the experimental sensitivity in near future. Therefore, the experimental signals of these decays may serve as a probe of the MSSM.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Fabio Bossi ◽  
Paolo Ciafaloni

Abstract Lepton Flavor Violating (LFV) processes are clear signals of physics beyond the Standard Model. We investigate the possibility of measuring this kind of processes at present and foreseeable future muon-electron colliders, taking into account present day bounds from existing experiments. As a model of new physics we consider a Z’ boson with a Ut(1) gauge symmetry and generic couplings. Processes that violate lepton flavor by two units seem to be particularly promising.


2021 ◽  
Vol 13 (3) ◽  
pp. 1057-1074
Author(s):  
P. Verma ◽  
- Vivekanand ◽  
K. Chaturvedi

The search for lepton flavor violation in charged lepton decays is a highly sensitive tool to look for physics beyond the Standard Model. Among the possible processes, µ-decays are considered to have the largest discovery potential in most of the standard model extensions. Many searches have been performed in the past, but no evidence has been found so far. In this paper, we have reviewed the current theoretical and experimental status of the field of muon to electron decay and its potential to search for new physics beyond the Standard Model. Future prospects of experiments for further progress in this field are also discussed.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Stefan Antusch ◽  
A. Hammad ◽  
Ahmed Rashed

Abstract We investigate the sensitivity of electron-proton (ep) colliders for charged lepton flavor violation (cLFV) in an effective theory approach, considering a general effective Lagrangian for the conversion of an electron into a muon or a tau via the effective coupling to a neutral gauge boson or a neutral scalar field. For the photon, the Z boson and the Higgs particle of the Standard Model, we present the sensitivities of the LHeC for the coefficients of the effective operators, calculated from an analysis at the reconstructed level. As an example model where such flavor changing neutral current (FCNC) operators are generated at loop level, we consider the extension of the Standard Model by sterile neutrinos. We show that the LHeC could already probe the LFV conversion of an electron into a muon beyond the current experimental bounds, and could reach more than an order of magnitude higher sensitivity than the present limits for LFV conversion of an electron into a tau. We discuss that the high sensitivities are possible because the converted charged lepton is dominantly emitted in the backward direction, enabling an efficient separation of the signal from the background.


2003 ◽  
Vol 18 (16) ◽  
pp. 2769-2778
Author(s):  
Graham D. Kribs

I explain the theoretical connection between lepton flavor violation and muon g - 2 in supersymmetry1. Given any central value deviation of muon g - 2 from the standard model that is assumed to be due to weak scale supersymmetry, I show that stringent bounds on lepton flavor violating scalar masses can be extracted. These bounds are essentially independent of supersymmetric parameter space. I then briefly compare this indirect handle on supersymmetric lepton flavor violation with direct observation at a future lepton collider operating in the e- e- mode. This is a summary of a talk given at e- e-01: 4th International Workshop on Electron-Electron Interactions at TeV Energies.


2006 ◽  
Vol 21 (27) ◽  
pp. 5652-5659 ◽  
Author(s):  
ANTONIO PICH

Precise measurements of the τ lepton properties provide stringent tests of the Standard Model structure and accurate determinations of its parameters. We overview the present status of a few selected topics: lepton universality, QCD tests and the determination of αs, msand |Vus| from hadronic τ decays, and lepton flavor violation phenomena.


2019 ◽  
Vol 35 (04) ◽  
pp. 1950359
Author(s):  
Ke-Sheng Sun ◽  
Jian-Bin Chen ◽  
Hai-Bin Zhang ◽  
Sheng-Kai Cui

Lepton flavor violation decays are channels which may lead to fundamental discoveries in the forthcoming years and this makes it an exciting research field for beyond the Standard Model (SM) searches. In this work, we present an analysis of the lepton flavor violation decays [Formula: see text] in Minimal R-symmetric Supersymmetric Standard Model. The prediction for [Formula: see text] depends on the off-diagonal entries of the slepton mass matrix. The contributions to Wilson coefficients can be classified into Higgs penguins, photon penguins, Z penguins and box diagrams. It shows the contribution from Z penguins dominates the predictions for [Formula: see text], and the contributions from Higgs penguins and box diagrams play different roles in different decay channels. The theoretical predictions for [Formula: see text] can reach the future experimental limits, and the channels are very promising to be observed in near future experiment.


2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
A. Vicente

Most extensions of the Standard Model lepton sector predict large lepton flavor violating rates. Given the promising experimental perspectives for lepton flavor violation in the next few years, this generic expectation might offer a powerful indirect probe to look for new physics. In this review we will cover several aspects of lepton flavor violation in supersymmetric models beyond the Minimal Supersymmetric Standard Model. In particular, we will concentrate on three different scenarios: high-scale and low-scale seesaw models as well as models withR-parity violation. We will see that in some cases the LFV phenomenology can have characteristic features for specific scenarios, implying that dedicated studies must be performed in order to correctly understand the phenomenology in nonminimal supersymmetric models.


2018 ◽  
Vol 33 (36) ◽  
pp. 1850214
Author(s):  
Ke-Sheng Sun ◽  
Xiu-Yi Yang

Taking account of the constraint from radiative two-body decays [Formula: see text], we investigate the lepton flavor violation decays [Formula: see text] in the framework of the minimal extension of the Standard Model with one neutral singlet scalar. The couplings [Formula: see text], [Formula: see text] and [Formula: see text] between the different generation leptons and scalar [Formula: see text] are constrained by the current bounds of [Formula: see text]. The numerical results show that the theoretical prediction of [Formula: see text] strongly depends on the couplings [Formula: see text] ([Formula: see text] or [Formula: see text]) between down-type quarks and new scalar. The contributions from couplings [Formula: see text], [Formula: see text] and [Formula: see text] between up-type quark and new scalar are less dominant.


Sign in / Sign up

Export Citation Format

Share Document