Necessary ingredients: proper decay time flavor at production, i.e. “tagging”: • = tagger efficiency •D = tagger dilution = 1 – 2w [w is the wrong tag probability] Only source of CP violation in the SM: complex phase in the CKM matrix but “not enough” to explain baryon - anti-baryon asymmetry occurs via 2 nd order weak diagrams 2 eigenstates of definite mass and width: H(eavy) and L(ight) extract V td , V ts and (more precisely) the ratio V td /V ts : • M s(d) = M H - M L ~|V ts(d) | 2 • = H - L , M sets the frequency of the flavor oscillations M =- 3 .7 –0 .8 +1.5 × 10 -3 P(B → B) = 1 2 -t cosh(t / 2) - cos(Mt) [ ] M s To probe CP violation deeper, check CKM matrix unitarity by over- constraining the Unitarity Triangle M d = 0.510 0.005 ps -1 small easy to resolve osci M s >14.4 ps -1 @95% C.L. large use AMPLITUDE SCAN met 1)A sym m etry(t)= N unm ixed -N mixed N tagged = A D cos M s t ( ) A s A = 2 2 S S S + B − M s 2 s ct 2 2 3) Signal significance S, S/(S+B) and s ct -- reasonable values achieved with SILICON TRACKER 2) Scan: A ~ 1 A ~ 0 otherwise D 2 : tagger dilutions measured in data M s = ΔM s real V ud V us V ub V cd V cs V cb V td V ts V tb ⎡ ⎡ ⎡ ⎡ ⎡ ⎡ ⎡ ⎡ ⎡ ⎡ Tagger 2 Soft Muon 5% 36% 0.56% Soft Elctr 4% 30% 0.29% Jt Charg 75% 8% 0.58% Total 84% --- 1.43% flavor at decay [consider flavor specific decays D s - + , D s - l + nX, …]