Beyond the Standard Model: the clue from charm ...

1. Beyond the Standard Model:the clue from charm ... • Precision study of b and c decays • deviations in expected behaviour of • b and c quarks evidence for new physics + • will elucidate new physics if found elsewhere • Rare decays • Mixing & CPV ..the clue from charm

2. To use the full power of b and c decays, theoretical calculations of strong interactions must be used. • The lattice gauge approach promises precision calculations that must be confronted with data • Precision measurements of the D+ and Ds decay constants • Semileptonic charm decay measurements Vcd and Vcs directly as well as input on hadronic matrix element ..the clue from charm

3. Direct signatures for new physics in charm decays Bigi-Sanda hep-ph/9909479 “A priori it is quite conceivable that qualitatively different forces drive the decays of up-type and down-type quarks . More specifically, non-Standard-Model forces might exhibit a very different pattern for the two classes of quarks”. Charm decays are the only up-type quarks that allow to probe this physics:non-strange light flavour hadrons do not allow for oscillations and top-flavoured hadrons do not even form in a practical way ..the clue from charm

4. Mixing & CPV Motivation: suppressed in the charm sector in the SM. If “measured”, would suggest SM extention BaBar measurement is @ 57.1 fb-1 ..the clue from charm

5. New limits expected by BaBar and Belle • Cleo-c @ 95% C.L. • CP violation • Direct CP violation in D0 and D+ • Indirect CP violation in D0 decays • CP violation measurements exploiting the quantum coherence of the D0 D0bar produced pair y(3770)  DD ; JP=1- • CP violation asymmetry sensitivity ACP<0.01 @ Cleo-c and Beauty Factories ..the clue from charm

6. Rare decays Motivation: lepton number violation study investigation of long range effects and SM extention FOCUS improved results by a factor of 1.7 –14: approaching theoretical predictions for some of the modes but still far for the majority CDF Br(D0m+m-)<2.4 x10-6 @ 90% C.L. is the best limit for this mode (65 pb-1 data) CDF and D0 can trigger on dimuons promising Cleo-c sensitivity 10-6 ..the clue from charm

7. Leptonic decays Motivations: decay constants measurements Lattice predicts fB/fD & fBs/fDs with small errors ..the clue from charm

8. Hadronic and semileptonic decays • Over constrain the “Unitarity Triangle” Inconsistencies New Physics semileptonic decays are the easiest way to determine CKM elements:QCD effects contained in form factors. Comparison with LGT and quark model calculations! ..the clue from charm

9. Vub/Vub 17% Vud/Vud 0.1% Vus/Vus =1% l l e B n n K n n p p  Vcs/Vcs =11% Vcb/Vcb 5% Vcd/Vcd 7% l D n l K B n l D D n p Vtb/Vtb 29% Vtd/Vtd =36% Vts/Vts 39% W Bd Bd t Bs Bs b Status of CKM Matrix Current VCKM From direct Measurements -no unitarity imposed CLEO-c will redefine 2nd generation elements And enable improvements in 3rd generation ..the clue from charm

10. Vub/Vub 17% Vud/Vud 0.1% Vus/Vus 1% 5% l l e B n n K n n p p  3% 2% 2% Vcd/Vcd 7% Vcs/Vcs 11% Vcb/Vcb 5% l D n l B n K l D Future VCKM D n p Vtd/Vtd 36% 5% 5% Vtb/Vtb 29% Vts/Vts 39% W Bd Bd t Bs Bs b Potential Impact on VCKM Current VCKM From direct Measurements -no unitarity imposed CLEO-c will redefine 2nd generation elements And enable improvements in 3rd generation ..the clue from charm

11. Summary of reach ..the clue from charm