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2 July, 2001 Columbia D0 Snowmass Meeting - H.Evans 1 Exp. Systematic Errors Most CP measurements use time-dep rate asymmetries  a dir,mix = func’s of.

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Presentation on theme: "2 July, 2001 Columbia D0 Snowmass Meeting - H.Evans 1 Exp. Systematic Errors Most CP measurements use time-dep rate asymmetries  a dir,mix = func’s of."— Presentation transcript:

1 2 July, 2001 Columbia D0 Snowmass Meeting - H.Evans 1 Exp. Systematic Errors Most CP measurements use time-dep rate asymmetries  a dir,mix = func’s of unitarity angles  + 4-quark operators if decay has contrib from >1 CKM amplitude  requires tagging flavor of B at production & decay  robust to 1 st order in exp. unknowns Categories of Syst. Error  Generally, difference in B & B-bar hadrons a.Production Asymmetries b.Tagging Efficiencies c.Mistag Rates d.Final State Acceptance e.Backgrounds Understand w/ Control Samples SampleChecksAccuracy * B +  J/  K + b,c0.1% / yr B d  J/  K 0* a (f 0 )0.1% / yr BsDsBsDs a (f s )? * LHC study

2 2 July, 2001 Columbia D0 Snowmass Meeting - H.Evans 2 Theoretical Uncertainties  Mainly when hadronic effects don’t cancel in ratio  introduce depend. on hadr. matrix elem’s (4-q op’s)  occur when >1 diagrams contribute to decay 1.Penguins  calc. |P/T| 2.Strong Phases     +  3.Final State Interactions  very hard to calc d W+W+ u ++ -- u W+W+ ++ -- d d u,c,t g u W+W+ u K+K+ 00 u d d B+B+ ++ K0K0

3 2 July, 2001 Columbia D0 Snowmass Meeting - H.Evans 3 Mode by Mode Breakdown ModeMeasExperimental SystTheoretical Syst B d  J/  K s  * ctrl sample stat’spenguinsfew % unitarity of CKM B d   +  -  /K separation?*  |P/T| < 10% required B d    * Dalitz sel. bias— B d  D *  +2  b  u << b  c hadr. M.E. & str phase BsDsKBsDsK  -2  * D s  ~ 20 D s K — B–D0K–B–D0K–  * BR ~ O(10 -7 )— B d  D K *  * small BR— B 0,–  K  eff(trig & reco)* SU(3) break & FSI B s  J/  K s  * B d  J/  K s bgrd SU(3) breaking B d  D + D -  trig & bgrd* penguins B d ,KK  * proper time res.SU(3) breaking * dominant systematic

4 2 July, 2001 Columbia D0 Snowmass Meeting - H.Evans 4 Beyond the SM Beyond the SM effects:  Large?:Mixing, Penguins  Small:Tree level decays CP Violation in Decays with & without Mixing  B d  J/  K s sin 2   sin (2  +  mix )  B d   K s sin 2   sin (2  +  mix +  pen )  K   K (meas) ~ 10 -3  D  K  mixing effect (~0 in SM)  EDMsFlavor diagonal CP violation (~0 in SM) Supersymmetric Models  In general  43 CP violating phases (c.f. 1 in SM)  CP violation sensitive to  (flavor) &  (soft-susy-breaking)   F >>  S  No new sources of flavor & CP violation   F <  S  Flavor & CP violation beyond CKM

5 2 July, 2001 Columbia D0 Snowmass Meeting - H.Evans 5 Beyond the SM Effects * Modeld N / 10 -25 e cm  mix  pen a(D  K  )a(K  ) SM< 10 -6 000O(1) MSSMO(10 2 )???O(10 7 ) Exact Univ< 10 -6 000= SM Approx Univ> 10 -2 O(0.2)O(1) ~ SM Alignment> 10 -3 O(1) O(10 -2 )~ SM Heavy Squark~ 10 -1 O(1) O(10 -3 )~ SM * stolen shamelessly from: Y. Nir, “CP Violation in and Beyond the SM” hep-ph/9911321


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