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Non-leptonic b → s,d decays (experiment) CKM 2014, Vienna, Austria 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL1.

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Presentation on theme: "Non-leptonic b → s,d decays (experiment) CKM 2014, Vienna, Austria 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL1."— Presentation transcript:

1 Non-leptonic b → s,d decays (experiment) CKM 2014, Vienna, Austria 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL1

2 b→d,s smorgasbord Try to cover aspects not discussed elsewhere. Included or excluded some topics at request of experiments or convenors: – Lepton Number Violation (LNV) in B decays. – B 0 (s) →invisible, γγ. – Baryonic B decays. – B→hhh (h=K, π ) in loops and trees. As a result: – Talk by committee. – Not a comprehensive review, just some highlights. – You may see some leptons. – You may see some b→u transitions. Mostly BaBar, Belle and LHCb results but must not forget contributions of CLEO, CDF, D0,… 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL2

3 Lepton Number Violation New Physics models can enhance Lepton Flavour Violation LFV and Lepton Number Violation LNV up to current experimental limits at colliders. Many LFV, LNV and Baryon Number Violation (BNV) searches are simple additions to core analyses (e.g. rare decays B 0 →l + l - or FCNC in B - →K (*) l + l - ). Can look for LNV, LFV and BNV at colliders in:  ϒ(nS) where n=2,3  B mesons  Charm mesons  Tau lepton decays LNV becomes possible if neutrinos are Majorana particles (ΔL=2 process). Some theories suggest a new 4 th generation neutrino. In B + →h - l + l + processes, can look for resonance production via Majorana neutrino exchange with masses in range GeV. Caveat: do not know mass nor coupling. Conclusion: well-worth looking for LFV, LNV and BNV at colliders. 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL3

4 X - = K -, π -, ρ -, K *-, D -, l + = e +, µ + (11 modes in total). LNV in B + →X - l + l’ + and in B + →h - µ + µ + 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL4 BaBar: PRD 89, (2014) LHCb: PRL 112, (2014) JHEP 05 (2009) 30 BaBar: PRD 89, (2014)

5 Summary of LNV results in B decays 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL5 CLEO: PRD 65, (2002) Belle: PRD 84, (2011) BaBar: PRD 85, (2012) LHCb: PRL 108, (2012) LHCb: PRD 85, (2012) BaBar: PRD 89, (2014) LHCb: PRL 112, (2014)

6 B 0 → invisible B 0 →υ ̄ υ(γ) strongly helicity suppressed: BF(B 0 →υ ̄ υ ) ~ Photon emission reduces helicity suppression: BF(B 0 →υ ̄ υγ ) ~ Can be enhanced in some NP models (e.g. R-parity violating SUSY, large EDMs,...) ~ with neutralino production e.g. PRD65, (2001). Dark Matter candidates. 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL6 Nucl. Phys B400, 225 (1993) SM Diagrams NP Diagram s

7 B0 → ῡυ(γ)B0 → ῡυ(γ) Belle/BaBar use tagged hadronic and semileptonic decays. Look for excess energy in detector (E extra or E ECL ). E * γ >1.2 GeV if require photon. 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL7 Babar: PRD 86, (2012) Belle: PRD 86, (2012) Signal B0 → ῡυB0 → ῡυ B 0 → υ ̄ υγ Generic B Non-B B0 → ῡυB0 → ῡυ

8 B 0 (s) → γγ B 0 → γγ and B 0 s → γγ closely related: b→d γγ suppressed wrt b→s γγ by |V td | 2 /|V ts | 2 ~0.04. BF(B 0 → γγ) estimated at 3.1 x 10 -8, BF(B s 0 → γγ) estimated at ( ) x Hadronic dynamics could alter this ratio. New Physics can enhance BF e.g. extended Higgs sector and RPV SUSY. 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL8 Belle: PRD 73, (2006) Belle: PRL 100, (2008) BaBar: PRD 83, (2011)

9 B Baryonic decays Baryons produced in pairs. One or more q̄q pairs have to be produced out of the vacuum. Many diagrams: calculations are difficult. Some predictions (M=Meson, B 1,2,c =Baryon): – BF(B→M 1 M 2 ) > BF(B→B 1 B 2 ) – BF(B→B 1 B 2 M) > BF(B→B 1 B 2 ) – BF(B→B c B c ) >> BF(B→B c B 1 ) >> BF(B→B 1 B 2 ) BF(B->baryons) = (6.8±0.5±0.3)% but only ~20% have actually been measured. 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL9 Many of these have Penguin loops as well

10 B-Factory B Baryonic decays 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL10 Tree dominated Penguin dominated CZ: NPB 345, 137 (1990) Jarfi: PLB 237, 513 (1990) CY: PLB 633, 533 (2006) BF (x ) b→d b→s b→d b→s Theory and experiment converging over the years B→B 1 B 2 M B→B 1 B 2 arXiv:

11 B - →Λ(1520)p ̄ and B + →pp̄h + (h=K, π) 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL11 LHCb: PRD 88, (2013) LHCb: EPJC (2013) 73:2462 LHCb Starting to measure charmless B  B 1 B 2 Also: evidence for B->ppbar seen at LHCb (JHEP 1310 (2013) 005)

12 B + →pp̄h + (h=K, π) 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL12 How to explain: pole models, bound states, glueballs, reflection, final state interactions, baryon form factors, … Belle: PLB 659, 80 (2008) LHCb: EPJC (2013) 73:2462 LHCb: PRD 88, (2013) LHCb: arXiv: Cos(θ p ) for B→pp̄K does not agree with simple pQCD prediction for b → sg*. A modified pQCD prediction gets B → pp̄K right but not B→ pp̄ π May indicate difference in b→ s penguin and b→u trees Evidence for change in CP asymmetry near threshold (m p̄p <2.85GeV). 4σ effect (m 2 Kp >10 GeV 2 ) 2.5σ effect (m 2 Kp <10 GeV 2 Difference in Forward- Backward Asymmetry in B→pp̄K and B→pp̄ π LHCb confirms many results first seen by Belle Evidence for CPV

13 Penguin Loops and Trees Contributions from both tree and penguins. Results from different flavour decays can help SM predictions. Three-body decays – 1 or 3 kaons: b→s penguin dominates – 2 kaons: b→u tree, b→d penguin New physics can affect loops: – Can enhance branching fractions – Changes in predicted CP asymmetries – Changes in predicted polarization – Changes in angular correlations Some overlap here with WG5. 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL13

14 B 0 s → φ φ and B 0 → φ K *0 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL14 LHCb: arXiv: LHCb: JHEP 05 (2014) 069 f L is similar to results from other B→VV penguin dominated decays

15 B + →h + h + h - (h=K, π ) 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL15 LHCb: PRL 111, (2013) LHCb; PRL 112, (2012) LHCb: arXiv: LHCb Preliminary LHCb Preliminary LHCb Preliminary LHCb Preliminary b→s penguin dominated b→u tree, b→d penguin

16 Conclusion Limits on LNV in B decays continue to improve. Approaching precision to measure the two-body baryonic decays B→B 1 B 2. Many more B→B 1 B 2 M modes still to come. Statistics on charmless B decays are such that more decay modes are becoming available to Dalitz analysis. Now able to look at interference across the Dalitz plane in great detail. By CKM 2016 could see at least a doubling of LHCb dataset (taken and analysed). 10-Sep-2014b -> s,d roundup, Fergus Wilson, STFC/RAL16


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