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Related papers: $\mu - e$ Conversion With Four Generations

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We investigate the Big-Bang Nucleosynthesis constraints on neutrino mixing in the framework of the two four-neutrino schemes that are favored by the results of neutrino oscillation experiments. We discuss the implications of these…

High Energy Physics - Phenomenology · Physics 2011-05-23 S. M. Bilenky , C. Giunti , W. Grimus , T. Schwetz

The $\mu$-$e$ conversion process is one of the most powerful ways to test lepton-flavor-violating (LFV) interactions involving charged leptons. The standard model with massive neutrinos predicts an extremely low rate for $\mu$-$e$…

High Energy Physics - Phenomenology · Physics 2026-04-09 Yu-Qi Xiao , Xiao-Gang He , Hong-Yi Niu , Rong-Rong Zhang

In the framework of the seesaw models with triplets of fermions, we evaluate the decay rates of $\mu \to e \gamma$ and $\tau \to l \gamma$ transitions. We show that although, due to neutrino mass constraints, those rates are in general…

High Energy Physics - Phenomenology · Physics 2010-05-12 A. Abada , C. Biggio , F. Bonnet , M. B. Gavela , T. Hambye

We present a new analysis of non-universal and flavor changing non-standard neutrino interactions (NSI) in \nu_e e or \bar{\nu}_e e scattering. Our global analysis of these process includes all relevant experiments, such as the most recent…

High Energy Physics - Phenomenology · Physics 2009-09-17 J. Barranco , O. G. Miranda , C. A. Moura , J. W. F. Valle

The observation of lepton flavour violation (LFV) in interactions involving charged leptons would be an unambiguous sign of physics beyond the Standard Model of particle physics. Given that muons can be produced at high intensities,…

High Energy Physics - Experiment · Physics 2023-10-25 Ann-Kathrin Perrevoort

We calculate the rates for the charged lepton flavour violating (LFV) decays l_i -> l_j gamma, tau -> l pi, tau -> l eta('), mu^- -> e^-e^+e^-, the six three-body leptonic decays tau^- -> l_i^- l_j^+ l_k^- and the rate for mu-e conversion…

High Energy Physics - Phenomenology · Physics 2014-11-21 Andrzej J. Buras , Björn Duling , Thorsten Feldmann , Tillmann Heidsieck , Christoph Promberger

We assess a mechanism which can transform neutrino-antineutrino asymmetries between flavors in the early universe, and confirm that such transformation is unavoidable in the near bi-maximal framework emerging for the neutrino mixing matrix.…

Astrophysics · Physics 2009-11-07 Kevork N. Abazajian , John F. Beacom , Nicole F. Bell

We demonstrate that mu/e slepton mixing is significantly more restricted than previously thought within the already remarkably flavor-safe R-symmetric supersymmetric standard model. We calculate bounds from mu to e gamma, mu to 3e and, most…

High Energy Physics - Phenomenology · Physics 2010-11-25 Ricky Fok , Graham D. Kribs

We compare two most relevant loop induced muon number violating processes, \mu --> e \gamma and \mu-e conversion in nuclei, in constraining new physics. Because of much richer structure of the latter process it may be enhanced with respect…

High Energy Physics - Phenomenology · Physics 2007-05-23 Martti Raidal

We explore the possibilities for extending the sensitivity of current searches for the charged lepton flavor violating decays $\mu\ -> e \gamma$ and $\mu\ -> eee$. A future facility such as Project X at Fermilab could provide a much more…

Instrumentation and Detectors · Physics 2013-10-01 Chih-hsiang. Cheng , Bertrand Echenard , David G. Hitlin

If the generating mechanism for neutrino mass is to account for both the newly observed muon anomalous magnetic moment as well as the present experimental bounds on lepton flavor nonconservation, then the neutrino mass matrix should be…

High Energy Physics - Phenomenology · Physics 2009-11-07 Ernest Ma , Martti Raidal

An analysis is given of the decay $\mu \to e+ \gamma$ in an MSSM extension with a vectorlike generation. Here mixing with the mirrors allows the possibility of this decay. The analysis is done at the one loop level with the exchange of…

High Energy Physics - Phenomenology · Physics 2015-06-26 Tarek Ibrahim , Ahmad Itani , Pran Nath

We consider the contributions to $g_\mu-2$ from fourth generation heavy neutral and charged leptons, $N$ and $E$, at the one-loop level. Diagrammatically, there are two types of contributions: boson-boson-$N$, and $E$-$E$-boson in the loop…

High Energy Physics - Phenomenology · Physics 2009-04-22 Wei-Shu Hou , Fei-Fan Lee , Chien-Yi Ma

Data from solar neutrino and KamLAND experiments have led to a discovery of nonzero neutrino masses. Here we investigate what these data can tell us about neutrino interactions with matter, including the poorly constrained flavor-changing…

High Energy Physics - Phenomenology · Physics 2008-11-26 Alexander Friedland , Cecilia Lunardini , Carlos Pena-Garay

The Mu2e Experiment at Fermilab will search for coherent, neutrinoless conversion of muons into electrons in the field of a nucleus, with a sensitivity improvement of a factor of 10^4 over previous experiments. Such a charged lepton…

Instrumentation and Detectors · Physics 2019-08-12 Raffaella Donghia

By combining experimental constraints from atmospheric and solar neutrino oscillations and the tritium beta decay endpoint, we infer upper limits of 4.4 eV on the $\nu_\mu$ and $\nu_\tau$ masses, if the universe consists of three neutrinos.…

High Energy Physics - Phenomenology · Physics 2009-09-15 V. Barger , T. J. Weiler , K. Whisnant

We investigate nuclear mu-e conversion in the framework of an effective Lagrangian arising from the inverse seesaw model of neutrino masses. We consider lepton flavour violation interactions that arise from short range (non-photonic) as…

High Energy Physics - Phenomenology · Physics 2009-09-17 F. Deppisch , T. S. Kosmas , J. W. F. Valle

We present the first detailed computation of the conversion of a bound muon into an electron mediated by a doubly charged $SU(2)$ singlet scalar. Although such particles are not too exotic, up to now their contribution to $\mu$-$e$…

High Energy Physics - Phenomenology · Physics 2016-10-03 Tanja Geib , Alexander Merle

Motivated by the recent strong experimental evidence of large \nu_mu-\nu_tau neutrino mixing, we explore current bounds on the analogous mixing in the charged lepton sector. We present a general formalism for dimension-6 fermionic effective…

High Energy Physics - Phenomenology · Physics 2008-11-26 Deirdre Black , Tao Han , Hong-Jian He , Marc Sher

New mu-to-e conversion searches aim to advance limits on charged lepton flavor violation (CLFV) by four orders of magnitude. By considering P and CP selection rules and the structure of possible charge and current densities, we show that…

Nuclear Theory · Physics 2023-04-04 W. C. Haxton , Evan Rule , Ken McElvain , Michael J. Ramsey-Musolf