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Precision Measurements at LHCb

Precision Measurements at LHCb. Niels Tuning Nikhef Colloquium, 23 September 2011. Assumption. In the rest of the talk I will assume the speed of light to be constant and that particles cannot travel faster than c. “Box” diagram: Δ B=2. s. b. s. b. b. μ. s. μ. B-physics Mission.

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Precision Measurements at LHCb

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  1. Precision Measurementsat LHCb Niels Tuning Nikhef Colloquium, 23 September 2011 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  2. Assumption • In the rest of the talk I will assume the speed of light to be constant and that particles cannot travel faster than c. Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  3. “Box” diagram: ΔB=2 s b s b b μ s μ B-physics Mission Search for new particles or forces via their virtual loop contributions in B-decays 2) Rare Decays: Search for enhanced BR’s or decay distributions that deviate from SM 1) CP Violation: Search for CP asymmetries incom- patible with SM fits. Study of couplings of New Physics “Penguin” diagram: ΔB=1 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  4. Motivation: The ‘DNA’ of flavour models From: A.Buras, arXiv:1012.1447 “Superstars”: Today also: W. Altmannshofer, et al., Nucl. Phys. B 830 (2010) 17 “The VIP’s of Bs Physics: Bs,d →µ-µ+and Sψφ” A.Buras,, arXiv 0910.1032 “From my point of view, similar to Sψφ , precise measurements of Br(Bs →µ-µ+) … are among the most important goals in flavour physics in the coming years.” Large NP effects Small NP effects No NP effects Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  5. “Box” diagram: ΔB=2 s b s b b μ s μ B-physics Mission Search for new particles or forces via their virtual loop contributions in B decays • 2) Rare Decays: • Search for enhanced BR’s or decay • distributions that deviate from SM • Examples: • B0 →K*μμ • B0s →μμ • 1) CP Violation: • Search for CP asymmetries incom- • patible with SM fits. • Study of couplings of New Physics • Examples: • Bs0 →J/ψφ “Penguin” diagram: ΔB=1 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  6. Reminder: the “box” for discoveries s b b s • ARGUS almost discovered the top quark: • mtop> 50 GeV • Lesson: • Loop diagrams are sensitive to heavy particles ARGUS Coll, Phys.Lett.B192:245,1987 ? Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  7. Menu: LHCb “Superstars” “Box” diagram: ΔB=2 s b s b b μ s μ • B0s → J/ψφ • B0 → K*μμ • B0s → μμ “Penguin” diagram: ΔB=1 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  8. Things I will not show… Charm B0 → Kπ B0→ DK*, B+→ DK+ B0→ K*γ B0s → φφ B*(*) spectroscopy Λb Bc+ → J/ψπππ Semi-leptonic W/Z D0→ KK D0→ππ B+c→ J/ψπππ B0s→φφ B0→ K*γ Λb0→ D0p+π- Λb0→Λc+π- Z0→μμ B0s→φγ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  9. Menu: LHCb “Superstars” B0s→ J/ψφ • B0s → J/ψφ • B0 → K*μμ • B0s → μμ B0→K*μμ B0s→μμ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  10. Commonality: “FCNC” γ b s • B0s → J/ψφ • B0 → K*μμ • B0s → μμ B0s→ J/ψφ B0→K*μμ B0s→μμ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  11. Commonality: “FCNC” γ b W t s • B0s → J/ψφ • B0 → K*μμ • B0s → μμ B0s→ J/ψφ B0→K*μμ B0s→μμ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  12. Sensitive to NP: appetizer B0s→ J/ψφ • B0s → J/ψφ • B0 → K*μμ • B0s → μμ (4/3)AFB B0→K*μμ B0s→μμ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  13. Status before Summer CDF, Conf Note 10206 B0s→ J/ψφ φs • B0s → J/ψφ • Decreased 3σ→ 1σ • B0 → K*μμ • Hint for deviaton • B0s → μμ • SM p-value 1.9% BABAR: PRL 102, 091803 (2009) CDF: Note 10047 (2010) Belle: PRL 103, 171801 (2009) B0→K*μμ CDF, arXiv:1107.2304 B0s→μμ mB Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  14. The LHCb Detector 23 sep 2010 19:49:24 Run 79646 Event 143858637 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  15. The LHCb Detector B0→K*μμ B0s→μμ PID B0→K*(Kπ)μμ Lifetime, B0s → J/ψφ RICH1 T MAGNET TT VELO MUON CALO RICH2 Interaction Point Suppress background, σ(MB) B0 →K*μμ B0s→μμ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  16. LHC and LHCb performance • LHC and LHCb show excellent perfomance • Recorded 330 pb-1 for Summer conferences • 1011 bb-pairs produced! x 4.3 • Optimal use of LHC beam: • “Lumilevelling” at 3.5 1032 • (Design was 2.0 1032 !) • Max. luminosity for entire fill Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  17. Detector efficiencies • Subdetector efficiencies >98% • Mainly due to dead channels • DAQ efficiency >90% • DAQ hick-ups • Deadtime Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  18. Menu: LHCb “Superstars” “Box” diagram: ΔB=2 s b s b b μ s μ • B0s → J/ψφ • B0 → K*μμ • B0s → μμ “Penguin” diagram: ΔB=1 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  19. B0s → J/ψφ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  20. B0s → J/ψφ: Introduction B0s→J/ψφ • Interfering decay amplitudes: • B0s→J/ψφ • B0s → B0s→ J/ψφ t >0.3 ps N = 8276 ± 94 σ ~ 7 MeV L ~ 337 pb-1 eiφ A.S.Dighe, I.Dunietz, R.Fleischer Eur.Phys.J.C6:647-662,1999 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  21. B0s → J/ψφ: Analysis • Angular analysis • B0s → J/ψφ: • Pseudo-scalar →2 vectors • CP ~ (-1)L • Flavour tagging b: use this b to check if other b oscillated Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  22. B0s → J/ψφ: Analysis • Angular analysis • B0s → J/ψφ: • Pseudo-scalar →2 vectors • CP ~ (-1)L • Flavour tagging • ω = 36% • εD2 = 2.08±0.41% • PDG: Δms=17.77 ±0.120 ps-1 • LHCb: Δms=17.725±0.041±0.025 ps-1 CP + CP - B0s→ J/ψφ Bs0→Ds-π+ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  23. B0s → J/ψφ: Angular Analysis Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  24. B0s → J/ψφ: Results LHCb-CONF-2011-049 • Most precise value of φs! φs=0.13 ± 0.18(stat) ± 0.07(sys) rad • Consistent with SM: φs=-0.03 ΔΓs=0.123 ± 0.029(stat) ± 0.008(sys) ps-1 = SM CDF:Γs=0.076 ± 0.059(stat) ± 0.006(sys) ps-1 D0:Γs=0.19 ± 0.07 (stat) ± 0.015(sys) ps-1 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  25. B0s → J/ψφ: Comparison Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  26. S.Stone, L.Zhang, Phys.Rev. D79 (2009) 074024 Intermezzo: B0s → J/ψf0 R.Fleischer, R.Knegjens, G.Ricciardi arXiv:1109.1112 • 2010: First observation at LHCb • f0is spin-0 • J/ψf0 is CP-odd eigenstate! • φs: no need for angular analysis LHCb, Phys.Lett.B698:115-122,2011. LHCb-CONF-2011-051 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  27. B0s → J/ψφ and f0: Combination • φs=0.13 ± 0.18(stat) ± 0.07(sys) rad • φs=-0.45+0.48-0.51rad Combination: • φs=0.03 ± 0.16(stat) ± 0.07(sys) rad B0s→ J/ψφ B0s→ J/ψf0 LHCb-CONF-2011-051 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  28. Intermezzo: B0s → J/ψKs K.de Bruyn, R.Fleischer, P.Koppenburg Eur.Phys.J. C70 (2010) 1025-1035 • Control subtle effects • like DCS Penguin contributions to sin2β • MeasuredBR(B0s → J/ψKs) : LHCb-CONF-2011-049 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  29. Sub-Summary • B0s → J/ψφ • B0 → K*μμ • B0s → μμ • Most precise measurement of φs • Combined with B0s → J/ψf0 • φs=0.03 ± 0.16(stat) ± 0.07(sys) rad • Measured DCS: BR(B0s → J/ψKs) Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  30. B0 → K*μμ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  31. B0→K*μμ: Motivation A.Ali, Th.Mannel, T.Morozumi Phys.Lett. B273 (1991) 505-512 • Hadronic uncertainties largely cancel in angular asymmetries • Forward-backward asymmetry AFB easiest μ+ θl K* μ- Example: (4/3)AFB • Zero-crossing point • particularly interesting: • Small hadronic uncertainties • Directly sensitive to C7 and C9 W.Altmannshofer et al., JHEP 0901:019,2009 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  32. B0→K*μμ: Status Belle, 657M BB PRL 103, 171801 (2009) • AFB measured at B-factories and CDF • All opposite sign for AFB? • Hint of deviation? Babar, 465M BB PRD 79, 031102 (2009) SM CDF 6.8 fb-1 arXiv:1108.0695 SM Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  33. B0→K*μμ: at LHCb ψ' • Reject J/ψandψ’ resonances • Veto peaking backgrounds • Select with boosted decision tree • B, J/ψ, K*vtx, FD, IP • N(B0→K*μμ) = 302 ± 20 • Babar: 60 • Belle: 247 • CDF: 164 J/ψ B0 LHCb-CONF-2011-038 N = 302 ± 20 L ~ 309 pb-1 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  34. B0→K*μμ: at LHCb ψ' • Reject J/ψandψ’ resonances • Veto peaking backgrounds • Select with boosted decision tree • B, J/ψ, K*vtx, FD, IP • N(B0→K*μμ) = 302 ± 20 • Babar: 60 • Belle: 247 • CDF: 164 J/ψ B0 LHCb-CONF-2011-038 1<q2<6 GeV2 N = 70 ± 10 L ~ 309 pb-1 N = 302 ± 20 L ~ 309 pb-1 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  35. B0→K*J/ψ: Asymmetry μ+ • Validate analysis on B0→K*J/ψ: • FL = 0.556±0.015 (Babar: 0.556±0.009±0.010) • AFB = -0.006±0.008 θl K* μ- NB: q2 = mJ/2 = 9.6 GeV2 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  36. B0→K*μμ: Asymmetry Ch.Bobeth,G.Hiller,D.van Dyk JHEP 1107:067,2011 • Validate analysis on B0→K*J/ψ: • FL = 0.556±0.015 (Babar: 0.556±0.009±0.010) • AFB = -0.006±0.008 • Measure AFB and FL in bins of q2 • Event-by-event acceptance correction LHCb-CONF-2011-038 m2μμ= Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  37. B0→K*μμ: Comparison J/ψ ψ' Belle, PRL 103, 171801 (2009) Babar, PRD 79, 031102 (2009) CDF, PRL 106, (2011) Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  38. B0→K*μμ: Asymmetry Ch.Bobeth,G.Hiller,D.van Dyk JHEP 1107:067,2011 • Still limited statistics • Good agreement with SM Example: LHCb-CONF-2011-038 (4/3)AFB W.Altmannshofer et al., JHEP 0901:019,2009 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  39. B0→K*μμ: Comparison Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  40. Sub-Summary • B0s → J/ψφ • B0 → K*μμ • B0s → μμ • Most precise measurement of AFB • Still limited statistical precision • More angular observables available Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  41. B0s → μμ Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  42. B0s→μμ: Motivation • Branching Ratio very sensitive to NP models • BR strongly enhanced in MSSM at large tanβ:  tan6/mA4 • Example: 10x higher BR for tan=50(20), mH+=800(200) GeV A.Buras, G.Isidori, P.Paradisi Phys.Lett.B694:402-409,2011 Allowed parameter space from fit in constrained MSSM: 1-CL tanβ=50 mH+=200 GeV Mt1=500 GeV, Mt2=850 GeV 5σ discov. CMS @30/60 fb-1: H,A → τ+τ− 10x SM 10x SM → tan  → MH+ (GeV) A.Buras et al., Nucl.Phys.B659:3,2003 O.Buchmueller et al. Eur.Phys.J.C64:391-415,2009 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium (Direct limits at CMS: Gennai et al. Eur.Phys.J.C52:383-395,2007)

  43. Intermezzo 2: Allowed MSSM parameter space • constraints. These include precision electroweak data, the anomalous magnetic moment of the muon, • (g − 2)μ, • B-physics observables (the rates for • BR(b → sγ) and • BR(Bu → τντ ), • Bs mixing, • and the upper limit on • BR(Bs → μ+μ−)), • the bound on the lightest MSSM Higgs boson mass, Mh, and the cold dark matter (CDM) density inferred from • astrophysical and cosmological data, assuming that this is dominated by the relic density of the lightest neutralino, χh2. Allowed parameter space from fit in constrained MSSM: CMS, Gennai et al. Eur.Phys.J. C52:383-395,2007 shown are the 5-σ discovery contours for observing the heavy MSSM Higgs bosons H,A in the three decay channels H,A → τ+τ− → jets (solid line), jet+μ (dashed line), jet+e (dotted line) at the LHC. The discovery contours have been obtained using an analysis that assumed 30 or 60 fb−1 collected with the CMS detector. O.Buchmueller et al. Eur.Phys.J.C64:391-415,2009 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  44. B0s→μμ: Motivation • Branching Ratio very sensitive to NP models • BR strongly enhanced in MSSM at large tanβ:  tan6/mA4 • Example: 10x higher BR for tan=50(20), mH+=800(200) GeV A.Buras, G.Isidori, P.Paradisi Phys.Lett.B694:402-409,2011 Allowed parameter space from fit in non-univ Higgs mass (NUHM): 1-CL tanβ=50 mH+=200 GeV Mt1=500 GeV, Mt2=850 GeV 10x SM 10x SM → tan  → MH+ (GeV) A.Buras et al., Nucl.Phys.B659:3,2003 O.Buchmueller et al. Eur.Phys.J.C64:391-415,2009 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  45. B0s→μμ: Motivation • Branching Ratio very sensitive to NP models • BR strongly enhanced in MSSM at large tanβ:  tan6/mA4 • Example: 10x higher BR for tan=50(20), mH+=800(200) GeV A.Buras, G.Isidori, P.Paradisi Phys.Lett.B694:402-409,2011 1-CL tanβ=50 mH+=200 GeV 2x10-8 1x10-8 Mt1=500 GeV, Mt2=850 GeV 5x10-9 10x SM 10x SM SM-like → tan  → MH+ (GeV) A.Buras et al., Nucl.Phys.B659:3,2003 Curves obtained through SuperIso, (eg. F.Mahmoudi, arXiv:0906.0369) Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  46. B0s→μμ: at LHCb Analysis based on Mass Kinematic / geometrical (lifetime, IPB, IPSμ, DOCA, isolation) > Compare observed to expectation Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  47. B0s→μμ: mass LHCb preliminary 2011 √s = 7 TeV L ~ 150 pb-1 B0s→μμ? 5.4 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  48. B0s→μμ: mass LHCb preliminary 2011 √s = 7 TeV L ~ 150 pb-1 B0s→μμ? 5.4 Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  49. B0s→μμ: mass • Mass resolution at mBs expected around 22 MeV σ(M) = 16 MeV σ(M) = 40 MeV J/ψ(1S) (1S,2S,3S) Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

  50. B0s→μμ: mass σ(M)mB = 24 MeV J/ψ(1S) σ(m) (MeV) (1S,2S,3S) mμμ (MeV) Niels Tuning - Precision Measurements at LHCb - Nikhef Coloquium

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