MeasurementIntro

Introduction to the Measurement

The Mu2e Experiment will measure the rate of muons that convert directly into electrons in the field of a nucleus without the accompanying neutrinos that the standard model of particle physics predicts. This process is all but forbidden in the standard model due to the apparent conservation of a property known as “flavor”. Muons have one flavor and electrons another. This means if flavor is conserved, a muon cannot decay to electrons without carrying forward the muon flavor in the interaction with the production of a muon neutrino. Likewise, an electron cannot appear in the decay without the cancellation of this new flavor with an anti-electron neutrino. Mu2e relies on momentum and energy conservation to determine whether the muon decay proceeded in a way that conserves flavor, or violates flavor conservation.

The Technique

(capture and monoenergetic signature)

Overview of Theories that Mu2e Will Probe

MSSM with right handed neutrinos

SUSY with R-parity Violations

Leptoquarks

New Gauge Bosons

Large Extra Dimensions

Non-Minimal Higgs Structure

A Brief History of the Measurement

The first search for muon to electron conversion was by Lagarrigue and Peyrou in 1952 [1], with many other searches carried out since then [2-9]. In this section we will more briefly describe a few of the more recent searches.

[1] A. Lagarrigue and C. Peyrou, Comptes Rendus Acad. Sci. Paris, 234, 1873(1952). See also J. Steinberger and H. Wolfe, Phys. Rev. 100, 1490 (1955).
[2] M. Conversi et al., Phys. Rev. D122, 687 (1961).
[3] R. Sard et al., Phys. Rev. 121, 619 (1961).
[4] G. Conforto et al., Nuovo Cimento 26, 261 (1962).
[5] J. Bartley et al., Phys. Lett. 13, 258 (1964).
[6] D. Bryman et al., Phys. Rev. Lett. 28, 1469 (1972).
[7] A. Badertscher et al., Phys. Rev. Lett. 39, 1385 (1977).
[8] S. Ahmad et al., Phys Rev. D38, 2102 (1988).
[9] W. Bertl et al., Eur. Phys. J. C47, 337 (2006).