jack

B+→τ+ν and BTauNuSemiLepUser: 

B+→τ+ν and BTauNuSemiLepUser Rome Group meeting, 30 Nov 2006

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Extract fB through leptonic decays: B+ → l+νl Cleanest source (1% measurements for π+,K+ ) Heavy B+: low branching ratios to leptons B+ B+ τ+ ντ (disfavours l=e, favours l=τ) Helicity Suppression (disfavours M = B, Bs, D) CKM mixing τ+ ν B meson decay constant W+ 2 Paul D. Jackson Group meeting-Rome

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Multiple neutrinos in the final state lacks experimental constraints Reconstruct B meson in the event with B→D(*)0lνX. Compare remainder of event with signature for signal decay. Techniques pioneered by BaBar!! B++, B-X (X=anything) Main  decay modes e,  , 0 B-D(*)0 lνX Choose best tag with P(Vtx) Apply cuts to suppress bkgd Analysis Strategy 324x106 BB pairs 3 Paul D. Jackson Group meeting-Rome

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Paul D. Jackson Result from ICHEP06 Interpret results with a modified frequentist technique. A ratio of likelihoods, includes systematics as Gaussians convoluted with the likelihoods ALL RESULTS ARE PRELIMINARY Observe a result consistent with zero signal at 1.3σ, so we set a limit and quote a central value. Calculate the product fB|Vub| “Naive” signal yield 4

Work since ICHEP: 

Work since ICHEP BTauNuSemiLepUser Paul D. Jackson Group meeting-Rome 6

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Paul D. Jackson Group meeting-Rome 7

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Paul D. Jackson Group meeting-Rome 8

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Paul D. Jackson Group meeting-Rome 9

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Paul D. Jackson Group meeting-Rome 10

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Paul D. Jackson Group meeting-Rome 11

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Paul D. Jackson Group meeting-Rome 12

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Paul D. Jackson Group meeting-Rome 13

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Paul D. Jackson Group meeting-Rome 14

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Paul D. Jackson Group meeting-Rome 15

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Paul D. Jackson Group meeting-Rome 16

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Paul D. Jackson Group meeting-Rome 17

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Paul D. Jackson Group meeting-Rome 18

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Result update: Vivace dataset Using all available data we have updated the entire analysis including systematics. Extracted all final numbers last night (see BAD note 1456 for details) PRD draft written and is BAD 1654 v2. Hope to submit very early in new year. Paul D. Jackson Group meeting-Rome 19