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Abi Soffer Colorado State University Super B Workshop, UH, Jan 19, 2004
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Outline NP-independent (incomplete list, hopefully representative) –sin 2 in B D 0 K (GW, ADS) –Recent developments B D 0 (CP) K B D 0 (non-CP) K, D 0 K Untagged B 0 –sin(2 + ) B 0 D ( * ( * )) ( * ) B 0 DK D 0 K 0 Comparison to NP- sensitive results Penguins Mixing Cautious predictions for ~10 ab 1 NP
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r e i( ) + e i D B+B+ b u u u c s K+K+ D0D0 B+B+ b u c u s u D0D0 K+K+ KK KK 1 Amplitude bubu bcbc sin 2 with B D (flavor+CP) K Atwood, Dunietz, Soni, PRL 78, 3257 (ADS) cos D measurable @ charm factory A.S., hep-ex/9801018 Gronau, Grossman, Rosner, PLB508, 37, 2001 Atwood, Soni, hep-ph/0304085 (1 r e i( ) ) CPES (CP eigenstate) r e i( ) Initial a 2 /a 1 ~ 0.25: r ~ 0.1 B 0 D 0 0, etc., suggest r ~ 0.2 Gronau, Wyler, PLB 265, 172 (GW) e i D
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Sensitivity A.S., PRD 60, 054032 L~600 fb 1, r = 0.1 B D ( * ) K ( * ) D K (n ) +, CPES True 33 33 22 58 o S : S ± : S : Resolved by large D
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New Developments More modes & methods – more statistics New methods reduce ambiguity to 2-fold More experimental experience Each of these methods satisfies the NIMSBHO principle: Not Inherently More Sensitive But Helps Overall (despite possible claims to the contrary…)
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Don’t Measure BR r 2 Jang, Ko, PRD 58, 111 Gronau, Rosner, PLB 439, 171 Determine r ( V ub /V cb color suppression) indirectly, from Color-suppressed b c modes NIMSBHO r
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SCS non-CP D Decay Modes B+B+ b u u u c s K+K+ D0D0 B+B+ b u c u s u D0D0 K+K+ KK (1+r r D e i( D ) ) 1 Amplitude bubu bcbc K K ... K K ... (r D +r e i( D ) ) No need to measure BR’s r 2, sensitive at O(r) BR measurable now S resolved – ambiguity only 4-fold r D = = 0.7 for K*K, measure with D*-tagged D 0 ’s D = arg Grossman, Ligeti, A.S. PRD 67, 071301 KK NIMSBHO
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D Dalitz Plot BaBar, hep-ex/0207089 22 fb 1 m 2 (K 0 + ) GeV 2 m 2 (K + ) GeV 2 D0K0KD0K0K D0K0KD0K0K There is also the K + K 0 mode
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D Dalitz Plot, D 0 0 CLEO, hep-ex/0305048 9 fb 1 m 2 ( 0 ) GeV 2 m 2 ( 0 ) GeV 2 r D = 0.65 ± 0.05 D = 4º ± 5º
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B+B+ b u u u c s K+K+ D0D0 B+B+ b u c u s u D0D0 K+K+ KK CP even (K + K ...) 1 (1 + r e i( ) ) Amplitude bubu bcbc Special Case: CP Modes Gronau, hep-ph/0211282 CP odd (K s 0...) (1 r e i( ) ) No need to measure BR’s r 2, sensitive at O( r 2 ) 8-fold ambiguity (when used standalone) KK NIMSBHO
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Sensitivity with CPES Only CP-even Belle CP-odd ambiguity M. Rama BR already measured: BaBar
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B D (multi-body) K Giri, Grossman, A.S., Zupan, PRD68, 054018, 2003 Expand to multi-body decay: Model-independent analysis: bin the D Dalitz plot B f K 1 + r D 2 r 2 + 2 r r D cos( B + D – ) |A(D f)| Arg(D f) Arg(D f) |A(D f)| 2 |A(D f) A(D f)| cos [or sin] D For a unique D final state f (such as a 2-body D decay): (From fit or charm factory: c i, s i 2 ) bin i B f i K T i + T i r 2 + 2 r [ cos( B – ) c i + sin( B – ) s i ] (From D* + D 0 + ) (From D* D 0 )
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Application to Cabibbo-Allowed D Decays NIMSBHO Divide the D K s Dalitz plot into n bins (n 4) 2n observables: (B + ) i & (B ) i in each bin n + 3 unknowns: c i, s i, r, B, m 2 (K s ) GeV 2 m 2 (K s ) GeV 2 ci cisi sici cisi si Resolves S . Resonances resolve S ± (essentially no model dependence) Belle Cabibbo-allowed: high statistics Dalitz plot suppression Best interference is around DCS decays This formalism is also needed for D K 0 and K (ADS/GW)
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Assume Breit-Wigner Resonances in D Decay BB BB Belle, hep-ex/0308043, 140 fb fb More model dependence, smaller statistical error
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Errors with 140 fb r = 0.33 ± 0.10 = 95° ± 23° ± 13° ± 10° = 162° ± 23° ± 12° ± 24° 90% CL: 0.15 < r < 0.50 61° < < 142° 104° < < 214° Asymmetry in B D syst has a significant 1/ N component
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Removing Color Suppression B+B+ b u u u c s K+K+ D0D0 B+B+ b u c u s u D0D0 K+K+ B+B+ b u c u s u D0D0 K+K+ u u 00 B+B+ b u u u s c D0D0 K+K+ u u 00 r ~ 0.4 instead of ~ 0.1 or 0.2 bubu bcbc Aleksan, Petersen, A.S., PRD 67, 0960XX
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Dalitz Plot Suppression D s **+ D* 0 K* + bububcbc Expect mostly NR-NR & NR-K* interference NR Simulation Small K(1430) – D s (2450) overlap Oliver et al, hep-ph/9801363 K(1430) D s (2450)
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Simulation Assuming NR/R ~ 0.4 (or equivalent interference), 400 fb 1, expect ~ 0.2 Resolves S . Resonances resolve S ± (essentially no model dependence) NIMSBHO
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1 rf eiDrf eiD New: from Untagged B 0 Decays Gronau, Grossman, Shumaher, A.S., Zupan B0B0 b d u d c s K0K0 D0D0 B0B0 b d c d u s K0K0 D0D0 f (B f K S ) = X(1+r f 2 ) + 2Yr f cos( D + ) Ar e i( ) Untagged rates: where X A 2 (1+r 2 ) Y 2A 2 r cos B Depend only on the B decay For N D decay modes: N+3 unknowns: D N, , X, Y Solvable with N 3 (or a multibody D mode) For 2 B decay modes, need only N 2 (B f K S ) = X(1+r f 2 ) + 2Yr f cos( D )
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Analytic Solution Special case: CP odd and even eignstate and 1 flavor state:
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Combining with B + Modes Best use of untagged B 0 modes is to combine them with results from B + decays (& tagged B 0 decays) with the same D modes: Every untagged B 0 mode adds 2 unknowns (X, Y) and 2 measurements ( (B f K S ), (B f K S )) D decay parameters & are the same as in the tagged/B + decays Expect significant improvement in overall sensitivity, since: Sensitivity is dominated by smallest interfering amplitude This amplitude has the same magnitude for B + and untagged B 0 (up to K S /K + reconstruction efficiencies, etc.)
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S = sin(2 ) b d hh d b c d d u D(*)D(*) d u c d hh D(*)D(*) t t sin(2 + ) with B D ( * ) h reirei ~0.02 , ,a 1 Dunietz, hep-ph/9712401
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B D ( * ) Analyses (full reconstruction) Belle, hep-ex/0308048, 140 fb BaBar, hep-ex/0309017, 82 fb
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B D* with Partial Reconstruction BaBar, hep-ex/0310037, 76 fb B D* + D 0 Reconstructed Not reconstructed Lepton tag Kaon tag Lepton tag Kaon tag
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B D ( * ) Results a r (S + + S ) = 2 r sin(2 ) cos( ) = magnitude of A CP c r (S + – S ) = 2 r sin( ) cos(2 ) 2 r D* S + D* 0.092 0.059 (stat) 0.016 (syst) 0.036 (D*ln) 2 r D* S D* 0.033 0.056 (stat) 0.016 (syst) 0.036 (D*ln) 2 r D S + D 0.094 0.053 (stat) 0.013 (syst) 0.036 (D*ln) 2 r D S D 0.022 0.054 (stat) 0.013 (syst) 0.036 (D*ln) Belle S sin(2 a D 0.022 0.038 (stat) 0.020 (syst) a D* 0.068 0.038 (stat) 0.020 (syst) c D 0.025 0.068 (stat) 0.033 (syst) c D* 0.031 0.070 (stat) 0.033 (syst) BaBar (full reconstruction) a D* (K tag) 0.054 0.035 (stat) 0.017 (syst) S + D* (l tag) 0.078 0.052 (stat) 0.021 (syst) S + D* (l tag) 0.070 0.052 (stat) 0.019 (syst) Avg. of a D* & (S + D* + S + D* )/2: 0.063 0.024 (stat) 0.014 (syst) BaBar (partial reconstruction, D* only) magnitude of A CP
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B D* Systematics (example) Specific to partial reco. Need to measure in data (big statistical component) For 10 ab 1, need to reduce these systematics by a factor of ~5 – 10 sin(2 ) D with partial reconstruction lepton tag Reduction by 2–3 seems very reasonable Both are currently quite conservative.
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from sin(2 + ) Silva, A.S., Wolfenstein, Wu, PRD 67, 036004 True Measured True few ab 1 So far seems small Allowed range Resolving ambiguities is crucial
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Sensitivity to r Hard to measure r from (1 r 2 )cos( m t), need to take it from B D s + Angular analysis with B D* a , exploit interference between the 3 helicity amplitudes to do away with r 2 terms London, Sinha, Sinha, PRL 85, 1807 The same can be done with B D** 2 D** resonances & continuum Resonance mass shapes add to angular information, resolves ambiguities Sinha, Sinha, A.S. r 2 r 1 Enough to measure terms r Expect significant improvement for this mode Perhaps large ’s will resolve ambiguities More complicated fit
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sin(2 + ) with Tagged B D ( * ) K s h hh c d s u D(*)D(*) d u cs hh D(*)D(*) dd KSKS dd KSKS r ~ 0.4 Aleksan, Petersen, hep-ph/0307371 Dalitz plot suppression Ambiguity only 2-fold ( Expect ~ 0.2 – 0.3 with 400 fb 1 NIMSBHO
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Tagged B 0 DK 0 Gronau, London, PLB 253, 483 Kayser, London, PRD 61, 116013 Atwood, Soni, PRD 68, 033009 r ~ 0.36 Data suggest r ~0.6 0.2 (10 9 B’s, sub-BR, tagging, no reco eff. Or bgd.) Belle, PRL 90, 141802 NIMSBHO
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with 10 ab 1 Use all methods –Will measure to ~ 2° (%) (stat) or less! –Only ambiguity is left Excluded theoretically? –The error is so small that ambiguities won’t matter
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Compare to from Penguins Theoretical uncertainties in precision extraction of Disagreement with “clean” measurements could be due to NP or EW penguins Theoretical understanding will improve by the time the machine is built B0B0 b d u d d / sd / s u + /K + B0B0 b dd u u d / sd / s bd
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Compare to |V td | from Mixing b d / sd / sb d / sd / s Straight forward comparison of |V td | & 1.4% 0.5% with 0.5 ab 1 Ronga, CKM ’03 BaBar, PRL 88, 221803 10% 1-2% “soon” Shoji Hashimoto (SLAC, Oct.) P. Lepage O(%) @ CDF xsxs x s / x s
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New Physics in the “SM-only” Measurements “Clean” measurements may not be absolutely clean NP has to look like tree-level charged current interactions –Charged Higgs? Such NP will presumably have a different effect on loop diagrams & other measurements. D 0 mixing may affect B DK. –Current limits on D mixing yield an effect at the few-degree level (Silva, A.S., PRD61, 112001) –The effect will decrease as D mixing limits tighten, or will be incorporated into the analysis once D mixing is measured
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Conclusions Many (albeit related) clean ways to measure –Frequent improvements & new ideas From foreseeable mixing, theory & lattice precision, the target for precision should be ~1° –May decrease by the time the machine is built, depending on developments in theory and experiment With 10 ab 1 we will –Measure to ~ 2° or less (statistical) –Resolve essentially all ambiguities –Understanding systematic errors at this level will be crucial This is a rough, cautious estimate. B factory data will provide much better estimates in 2-3 years
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Backup slides Fraction of allowed range of excluded by this exp. 0 0.51 A.S., PRD 60, 054032
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Belle Dalitz fit
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Sensitivity with CPES + K*K CP modes K* + K Combined True 0.5 ab
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