Li = Σ # LeptonsGen i – # AntileptonsGen iconserved in the Standard Model

Wolfgang Pauli

n p e-e

- -

-decays:

today: many examples

neutrinooscillations

violatelepton

number !

-

-

W-

- -

annihilation

forbidden:

-

-

W-

- - forbidden:

neutrino oscillation

but: energy/momentum conservation

-

-

W-

- - forbidden:

neutrino oscillation

but: energy/momentum conservation

-

-

W-

- - + -

Z+

-

-

-

W-

- - 0

Z 0

-

-

W-

- -

neutrino oscillation

-

-

i

W-

- -

Ui

Ui

Euro Phys J C8 (1999) 513, hep-ph/9810484

for discussion see Tord Riemanns home-pagehttp://www-zeuthen.desy.de/~riemann/

new physics breaks GIM

new physics breaks GIM

SUSY SO(10) NPB649(2003)189 PRD68(2003)033012 10-8 10-10

SUSY HIGGS PLB549(2002)159 PLB566(2003)217 10-10 10-7

mSUGRA EPJC14(2000)319 PRD66(2002)115013 10-7 10-9

non-universal Z´ PLB547(2002)252 10-9 10-8

Heavy Maj. NR PRD66(2002)034008 10-9 10-10

Some theoretical estimates

currently best limits !

approaching 109 -pairs

- -

Belle 2004: < 3.1 10-7

BaBar 2005: < 6.8 10-8

BaBar

currently best limits !

approaching 109 -pairs

- -

Belle 2004: < 3.1 10-7

BaBar 2005: < 6.8 10-8

BaBarprel. ’03 final ‘05

(/e-tag) 5.2 % 3.8 %

(total) 9.4 %

exp. BGD (/e) 7.8 ev. 2.8 ev.

(total) 6.2 ev.

limit (10-8) < 200 < 6.8

b-factories reaching the limits at x 10-8

sources at the LHC:

p p W

p p Z/

p p B0 X

p p B± X

p p Bs X

p p Ds X

1.7 108

8.0 108

4.0 1011

3.8 1011

7.9 1011

1.5 1012

1 year runninglow luminosity

plenty of taus !

no chance to see- -

Try- - + -

Simulation with underlying eventlow luminosity

Source: W

Trigger: Single-Muon L1: pT > 14 GeV HLT: pT > 19 GeV

Trigger: Di-Muon L1: pT > 3 GeV HLT: pT > 7 GeV

Looks okay 1.7 108 per year

DS - Source

Trigger: Single-Muon L1: pT > 14 GeV HLT: pT > 19 GeV

Trigger: Di-Muon L1: pT > 3 GeV HLT: pT > 7 GeV

Trigger-Eff. only 1% 1.5 1012 per year

Background Problem with DS source

DS 1 % br.10-5 br.

Does anybody know of a generator for this process ?

-

-

W-

- - + -

Z+

-

-

-

W-

- + - -

Z+

-

+

-

- + - +

Z+

-

+

-

p p Z - +

Zp

p

+

-

p p Z - +

Zp

pW

Can we improve a few channels at LHC ?Also look for LVF in Z-decays at LHC !

LFV tau-decays Interesting search for physics beyond the S.M. (SUSY and others )

b-factories will approach 10-8