K. Long – U.C. Irvine - p. 1/

Muon Physics at the front end of a -Factory• At a -factory beams of 1013 - 1014 /s

could be developed. • Two types of experiments are especially

suited to such fluxes:– Search for a permanent electric dipole moment

d

– Search for lepton flavor violation in muon decay

• Such experiments would continue the long history that muon physics has with the development of the Standard Model, and searches for physics beyond it.

K. Long – U.C. Irvine - p. 2/

SM information/constraints from the muon:

• The strength of the weak interaction– i.e. the Fermi constant G from

• The fundamental nature of the weak interaction: V-A

• Lepton flavor conservation in -decay: → e , + → e+ e+ e-, N → e- N, are not yet seen

• VEV of the Higgs field:

• Induced form-factors in nuclear -capture• Limits on non-standard model physics from

the muon anomalous magentic moment a

K. Long – U.C. Irvine - p. 3/

• Muon Magnetic Dipole Momoment a chiral changing

• Muon EDM

P T CP

Three experiments that would most benefit from high flux:

K. Long – U.C. Irvine - p. 4/

Three experiments that would most benefit from high flux:• Muon Magnetic Dipole Momoment a chiral

changing

• Muon EDM

• Lepton Flavor Violation

P T

K. Long – U.C. Irvine - p. 5/

aμ, d LFV are sensitive to a wide range of new physics including SUSY. e.g. a is sensitive to:

• substructure

• SUSY (with large tanβ )

• many other things (extra dimensions, etc.)

K. Long – U.C. Irvine - p. 6/

The new theory value reported by S. Eidelman at ICHEP06 a difference with SM of 3.3

K. Long – U.C. Irvine - p. 7/

Left -Right

MSSM ~

Multi Higgs

MSSM

~ 1

10-24

10-22

10-26

10-28

10-30

10-32

10-34

10-36

e EDM (e.cm)

E. Hinds’ e-EDM experiment

at Imperial College with YbF molecules

is startingto explore this region

Standard Model

de < 1.6 x 10-27 e.cm

Commins (2002)

Excluded region (Tl atomic beam)

with thanks to Ed Hinds

n

199Hg

K. Long – U.C. Irvine - p. 8/

SUSY connection between a , Dμ , μ → e through the slepton mixing matrix → e MDM, EDM

~ ~

K. Long – U.C. Irvine - p. 9/

Past and Future of LFV Limits

+ e-→-

e+

Bra

nchi

ng R

atio

Lim

it

K. Long – U.C. Irvine - p. 10/

Experiments that can use the highest muon intensity:

• muon-electron conversion: to ~ 10-20

– Present Limit for - Ti: BR < 6 X 10-13

– PRISM/PRIME proposal •10-18 – 10-19 single event sensitivity

– -Fact front-end, 10-20

• muon EDM search– ~10-25 e cm needs NP2 of ~1018

– present limit d 10-19 e cm<~

K. Long – U.C. Irvine - p. 11/

Muon Summary and Outlook• The muon has provided us with much knowledge on

how nature works. New experiments on the horizion continue this tradition.

• Muon (g-2), with a precision of 0.5 ppm, has a 3.3 discrepancy with the standard model.

• If this discrepancy is from new physics, it would show up in an EDM and perhaps in LFV as well.

• MEG is set to turn on and collect data in the next year. • - → e- conversion holds the best experimental

prospect for going much further on LFV.

• There is an exciting program of muon physics that can be done at a -factory!

K. Long – U.C. Irvine - p. 12/

THE END

K. Long – U.C. Irvine - p. 13/

K. Long – U.C. Irvine - p. 14/

The SM Value for electron and muon anomalies

e vrs. : relative contribution of heavier things

e,

e*,

e,

e,

e,

e, e,

e,

e,

e,e,

K. Long – U.C. Irvine - p. 15/

Present EDM Limits

Particle Present EDM limit(e-cm)

SM value(e-cm)

n 3 x 10-26 (90%CL) 10-32 to 10-31

e- 1.6 x 10-27 (90%CL) < 10-41

< 10-38

199Hg 2.1 x 10-28 (95%CL)

*not yet final

K. Long – U.C. Irvine - p. 16/