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Flavor Physics

Flavor Physics. CKM Matrix B Physics Production New States Lifetimes B s Mixing CP Violation Other Measurements Top Physics Production Spin Correlation W Polarization V tb. Quarks: Flavor. CKM Matrix of Flavors: u,d,c,s,t,b. ). (. Wolfenstein Representation. ). (.

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Flavor Physics

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  1. Flavor Physics • CKM Matrix • B Physics • Production • New States • Lifetimes • Bs Mixing • CP Violation • Other Measurements • Top Physics • Production • Spin Correlation • W Polarization • Vtb

  2. Quarks: Flavor CKM Matrix of Flavors: u,d,c,s,t,b ) ( Wolfenstein Representation ) ( Different Processes give different elements

  3. FNAL CKM Measurements “CKM” “KTeV”, “KAMI” B Physics Colliders?

  4. Measured by CLEO+LEP • at 20% level • RatioDmd/Dms or • radiative B decays • (r,h) Vub* l Vcb Vtd l Vts a g b • (0,0) • ACP in B0p+p-??? • ACP in B0J/y Kos • ACP in Bs0DsK CP violation in B decays • (1,0)

  5. B Physics: Production • Central Rapidities • Rapidity Dependence

  6. B Physics at the Tevatron sbb 100 mb sbb 10-3 sp Bd0 , B- , Bs0 , Bc , Lb all produced Two main trigger samples: • J/y  m+m- • high pt leptons To improve S/N: • good mass resolution • displaced vertex cuts SELECTED CDF RESULTS • M(B-) = 5279.1 ± 1.7 ± 1.4 Mev/c2 M(Bd0) = 5281.3 ± 2.2 ± 1.4 Mev/c2 • G(Bs0 ) = 1.36 ± 0.09 ± 0.06 ps G(Bs0 )/ G(Bd0 ) = 0.899 ± 0.072 • Bc discovery • J/y  m+m-decay length • Prompt J/y • Side-band background • J/yfrom B’s

  7. B Physics: Heavier States • Bc Observation

  8. B_c Lifetime

  9. B_c

  10. B Physics: Lifetimes • Neutral and Charged very close • Note higher mass states Bs, Lb

  11. N(t)(B0 B0) - N (t)(B0  B0) b W d, s • N (t)(B0  B0) + N(t)(B0  B0) u c t u c t Bod Bod d b W • Opposite side tagging Bd0 and Bs0 mixing • Vtb1 A(t) = = cos ( Dmqt) • reconstruct B-decay • measure displaced vertex • tag B-flavor at production: • Soft Lepton Tagging (SLT) • Jet Charge Tagging (QJT) • Same Side Tagging (SST) CDF has five independent Bd0 mixing measurements: Dmd = 0.481 ± 0.028 ± 0.027 ps-1 CDF has also limits for Bs0 mixing: Dms > 5.8 ps-1 @ 95% CLfrom Bs0flnX Dms < 96 ps-1 @ 95% CLfrom Bs0DslnDG/G anal. • Xq= Dmq/Gq  Vtq • Vtd • Like-sign mm asymmetry vs decay-length

  12. sin (2b) measurement • N(t)(B0f ) - N (t)( B0  f ) • ACP(t) = = sin (2b) sin (Dmdt) f is J/y Ks0 Measured asymmetry: Amea(t) = DACP(t) Use multiple B flavor tagging algorithms: SST SLT JCT eD2 (%)1.80.5 0.910.15 0.780.14 0 < sin( 2b)< 1 @ 93% CL (Feldman-Cousin statistics) Important Demo at least!!! • N(t)(B0 f ) + N (t)(B0  f )

  13. SIN(2b) FLAVOUR TAGGING eD2CDF ICDF II CDFII +TOF SST(p)1.8%2.0%2.0% JCT0.8%3.0%3.0% SLT0.9%1.7%1.7% KAON- -2.4% RUNII : sin 2b • SIN(2b) SENSITIVITY • statistics of fully reconstructed B-decays is expected to increase by: Run II luminosity sbb(s) increase Efficiency x Acceptance e+e- channel For 2fb-1 : CDF II d(sin 2b) = 0.078 CDF II+TOF d(sin 2b) = 0.067 D0 d(sin 2b) = 0.10

  14. B Physics Measurements • Bs Mixing • use states…... • 20,000 Bs with SVT trigger • tagging using …. xs Reach 40 - 60

  15. B Physics: Other Measurements • CP Violation in Bs • BsJ/y f • sin 2a , sin 2g • ( tough, need rate, id, space resolution) • Rare Decays A Rich and Extensive Program in good part beyond the B Factory reach Asymmetry error vs. xs

  16. Top Quark Production Cross Section (DØ) tt= 5.9  1.7 pb (CDF) tt= 7.6  1.8 pb Assuming BR(t Wb) = 100, the measured top quark pair-production cross section agrees well with the SM prediction.

  17. (NEW!) New CDF top production cross section: 6.4  pb. 1.5 1.3

  18. W Polarization in Top Decay • SM predicts fraction of longitudinally polarized W’s • from top decay: F0 = M2top/(Mtop2 + 2MW2) = 0.70 • Extract W helicity fractions from the shape of the • charged lepton pT spectrum in t bWb • better measured than angular correlations • unaffected by  reconstruction or combinatorics • assume a mixture • of longitudinally • polarized and • negative helicity • W’s produced • in top decay • use a maximum • likelihood method • to estimateF0 • (assume positive • helicity fraction • F+ = 0) F0 = 0.97  0.37  0.12 (assume F0= 0.75)F+ = 0.11  0.15  0.06

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