Strange Beauty and Other Beasts: At and Above the Υ(5S) with Belle

Transcription

1 SLAC, October 21, 2008 Strange Beauty and Other Beasts: At and Above the Υ(5S) with Belle Belle/KEKB, Υ(4S) Resonance, B meson Υ(5S) Resonance and B s motivation Belle data & results prospects Kay Kinoshita University of Cincinnati Belle Collaboration

2 The people 2 Belle collaboration Aomori U. BINP IHEP, Vienna Chiba U. Chonnam Nat l U. Kanagawa U. U. of Cincinnati Ewha Womans U. Frankfurt U. Gyeongsang Nat l U. U. of Hawaii Hiroshima Tech. IHEP, Beijing IHEP, Moscow ITEP KEK Korea U. Krakow Inst. of Nucl. Phys. Kyoto U. Kyungpook Nat l U. EPF Lausanne Jozef Stefan Inst. / U. Ljubljana / U. of Maribor U. of Melbourne Seoul National U. Shinshu U. Nagoya U. Nara Women s U. National Central U. Sungkyunkwan U. U. of Sydney National Taiwan U. National United U. Nihon Dental College Niigata U. Tata Institute Toho U. Tohoku U. Osaka U. Osaka City U. Tohuku Gakuin U. U. of Tokyo Panjab U. Peking U. Tokyo Inst. of Tech. Tokyo Metropolitan U. U. of Pittsburgh Princeton U. Tokyo U. of Agri. and Tech. Toyama Nat l College Riken Saga U. U. of Tsukuba VPI USTC Yonsei U. ~14 nations, 55 institutes, ~400 collaborators (authors vary, each paper)

3 ... the hardware 3 22 mr 3.5 GeV Belle detector KEKB B-factory 8.0 GeV βγ = /07- COPPER pipelined DAQ system L max = 1.71 X cm 2 s 1 (world record) crab RF cavities 4/07- L = 1.6 X cm 2 s 1 cavity Charged tracking/vertexing SVD: (-7/03) 3-layer DSSD Si µstrip (152M B pairs) (8/03-) 4-layer (550+M BB) CDC: 50 layers (He- ethane) Hadron identification CDC: de/dx TOF: time-of-flight ACC: Threshold Cerenkov (aerogel) Electron/photon ECL: CsI calorimeter Muon/K L KLM: Resistive plate counter/iron e + source

4 ... the Physics (mostly) 4!(4S) } B Primary goal: study CP violation in weak decays of B meson Data (6/1999 9/2008) 9/2008) Ldt = ~820 fb (>8x10 8 B events)

5 ... but there s MUCH more! papers published/in press/submitted (3/2001-) CP asymmetry in B decay B decays charm tau 2-photon addressing CP, CKM, QCD, HQ spectroscopy,... occasional overlap of topics e.g., new charmonium(-like) states in B decay. Non-4S Data ( 9/2008)( Ldt = 24.6 fb (1.3 x 10 6 B s events) Ldt = ~8 fb scan + Υ(3S), Υ(2S)... and now, ϒ(10860), 5S B s decays & CP, search for New Physics Upsilon, B s spectroscopy

6 ... more: Υ(5S) 6 CLEO PRL 54, 381 (1985) continuum

7 ... more: Υ(5S) 7 CLEO PRL 54, 381 (1985) ϒ(4S) M=10580±1 MeV/c 2, Γ=20.5±2.5MeV ϒ(5S) M=10865±8 MeV/c 2, Γ=110±13 MeV B s produced copiously in pp(bar) collisions (FNAL, LHC) could B-factories (competitively) study B s at the Υ(5S)? pro s (A. Drutskoy) MUCH cleaner, better energy definition, event efficiency, clean γ s B-factory: high luminosity, established detector, compare w Υ(4S)

8 Υ(5S) physics 8 B s studies Low CP-asymmetry in SM -> sensitivity to New Physics SM CP violation is insufficient to explain baryon asymmetry Mod. Phys. Lett A9, 75 (1994); PRD 51, 379 (1995); Nucl.Phys. B287, 757 (1987) ΔΓ/Γ CP /Γ=O(10%) in SM -> differences in CP, flavor eigenstates Absolute B s branching fractions Similarity/difference w (non-strange) B -> quark-hadron duality, fine-tune hadronic models B (*) s mass Υ(5S) spectroscopy B (*) (s) (π) event fractions Other bottomonium-like states?

9 B s decays: outline 9 Similarity w B u,d dominated by spectator process similar semileptonic widths D->D s for many modes difference CKM-favored AND flavor-neutral CP=+1 in heavy quark limit, m c -> ~ saturated by 2-body D s (*)+ D s (*) -> difference in widths of CP=±1 What about CP violation? Aleksan, Dunietz, Kayser Z. Phys., C54, 653 (1992)

10 weak force, flavor, & CP violation 10 Unlike leptons, which exhibit no generation-xing couplings Weak couplings of quarks: neutral current universal, generation-conserving charged current approx. generation-conserving, but different u c t Z 0 "neutral current" not seen W ± charged current" favored suppressed d s b

11 weak force, flavor, & CP violation 11 Weak charged-coupling matrix for quarks d s b g F x u V ud V us V ub c V cd V cs V cb t V td V ts V tb 9 complex couplings -> 18 free parameters GIM (Glashow-Iliopoulos-Maiani) mechanism universal & generation-conserving g F x d s b u c t weak eigenstates, mass eigenstates d, s, b d' s' = b' d s b Cabibbo-Kobayashi- Maskawa (CKM) matrix

12 weak force, flavor, & CP violation 12 Weak couplings of quarks: CKM matrix d' s' = b' d s b complex preserves metric Elegance Restored orthogonality unitary Explains suppression of flavor-changing neutral currents multiplicity of charged current couplings AND.

13 13 for >2 generations, e.g. 3, {9R+9I} dof constrained by unitarity: 4 free parameters, incl. 1 irreducible imaginary part (Kobayashi-Maskawa 1973) Makoto Kobayashi First 3rd- generation particle (τ)( seen 1975 Toshihide Maskawa

14 14 for >2 generations, e.g. 3, {9R+9I} dof constrained by unitarity: 4 free parameters, incl. 1 irreducible imaginary part Unitarity conditions V * ji V jk =δ ik explicit parametrization(wolfenstein): 1!"2/2 " " 3A(#!i$)!" 1!"2/2 "2A "3A(1!#!i$)!"2A 1 irreducibly complex matter-antimatter asymmetry requires CP-violating interactions (Sakharov 1967) CKM explains observed CP, appears insufficient for universe

15 CP asymmetry in B s -> J/ 15 Analogous to B -> J/ψ K s (Sanda/Bigi/Carter) mixing+tree ( V *2 td ) tree (real V ij ) B V cb* V cs s c c J/ψ }Ks measured V *2 tb V ts2 V cb V * cs c c identical hadronic processes CP-dependent oscillation in time from x-term(s) - no theoretical uncertainty: arg(v *2 tb V ts2 ) = 0 s J/ψ }Ks No mixing-mediated CP violation in SM -> any CP asymmetry is NP... something for the future...

16 data 16 June 2005: 3-day engineering run to study ϒ(5S) properties, B s prospects test KEKB - L max ~1.39x10 34 cm -2 s -1 energy scan, 5 points, 30 pb 1 each 1.86 fb 1 at peak 4 x largest previous sample (CLEO) A. Drutskoy et al., PRL 98, (2007) A. Drutskoy et al., PRD 76, (2007) June 2006: 20-day run 21.7 fb 1 on peak total = 23.6 fb GeV

17 Fundamentals 17 Event count (3.01±0.02±0.16)x10 5 events/fb fb 1 Event shape parameter (Fox-Wolfram moments) 3x jet R 2 ->1 1 Continuum 3.67 fb 1 (scaled) R 2 ->0

18 Fundamentals 18 B s fraction in Υ(5S) events inclusive D s production (model estimate) (measured) similar analysis using inclusive D 0 : f s =(18.1±3.6±7.5)% combined: continuum

19 19 R. Louvot, J. Wicht, O. Schneider, et al. arxiv: [hep-ex], submitted to PRL

20 B s at ϒ(5S): mix of 20 Candidate reconstruction: energy, momentum -> ΔE, M bc B s *B s * B s *B s B s B s MC simulation

21 data 21 B s *B s * slice/projection measure masses: <p Bs > = p B* slice/projection 23.6 fb 1 <E Bs > = E beam - <ΔE>

22 data 22 B s *B s 23.6 fb 1 significance = 2.7σ

23 24 B s *B s * only (statistics) K ID is crucial MC simulation

24 data 25 B s *B s * 23.6 fb 1 significance = 3.5σ

25 results 26

26 27 Searches for radiative modes of B s J. Wicht, et al. PRL 100, (2008)

27 Searches for new modes of B s 28 γγ: difficult for hadron machines beyond SM: up to 5x fb 1 (prev. Belle: <5.3 x 10 5 )

28 Searches for new modes of B s 29 φγ 23.6 fb 1 First observation

29 30 A. Drutskoy, et al. PRD 76, (2007)

30 Searches for new modes 31 D s (*)+ D s (*) : CKM favored, first sensitivity to Analyze 3 modes together; little background -> 23.6 fb 1 : in progress 1.86 fb 1 CDF 2007:

31 32 K.-F. Chen, W.-S. Hou, M. Shapkin, A. Sokolov, et al. PRL 100, (2008)

32 Is the ϒ(10860) purely ϒ(5S)? 33 recently found in e + e collisions: New charmonium-like particle at 4260 GeV Others Babar PRL 95, (2005) Belle PRD 77, (R) (2008) CLEO PRD 74, (R) (2006) +more - than predicted!

33 Is the ϒ(10860) purely ϒ(5S)? 34 recently found in e + e collisions: New charmonium-like particle at 4260 MeV Others Babar PRL 95, (2005) Belle PRD 77, (R) (2008) CLEO PRD 74, (R) (2006) +more - than predicted! Does(do) analogous state(s) Y b exist in Upsilon region? [W.S. Hou, PRD 74, (2006)]

34 Is the ϒ(10860) purely ϒ(5S)? 35 ϒ(4S) ϒ(5S) Does(do) analogous state(s) Y b exist in Upsilon region? [W.S. Hou, PRD 74, (2006)]

35 Is the ϒ(10860) purely ϒ(5S)? 36 -> look for: M(µµππ) = E cms

36 Is the ϒ(10860) purely ϒ(5S)? 37 4 modes seen Expectation: Υ(5S) width comparable to Υ(2S/3S/4S) larger by > 10 2 Conclusion: not pure Υ(5S)? 12/07 energy scan, search for anomalous

37 Followup: scan above (5S) 38

38 K-F Chen BELLE-CONF-0861 ArXiv: Hadronic peak

39 Summary 40 KEB and Belle at Υ(10860) 23 days, 23.6 fb 1, 1.3M B s events 8 fb 1 near and above Υ(10860) Beast(s) anomalous Υ(ns) (ns)ππ,, ~10 2 X expectation at Υ(10860) Υ(ns) (ns)ππ rate peaks ~ 20 MeV above hadronic peak -> Υ(10860): not pure Υ(5S)? Strange beauty large sample of B s -> D s π, evidence D s K B * s B * s rate, masses of B * s, B s best limit on B s -> γγ first observation of B s -> φγ more to come... October 2008, extended run ->?? fb fb 1

40 B factory: 41 off resonance on ~10% resonance ~90% Δt by asymmetric energy e + e - ->Υ(4S (4S) (symmetric ϒ(4S): CLEO ) e - e + t=0 B 2 B 2 decay at t=δt Δz Δτβγc ~200 µm CP t=δt BR < 10 3 ϒ(4S) CP=+1, conserved B 1 B 1 decay (t=0), break CP flavor : e, µ, K ±,... effective eff ~30%

41 42 for >2 generations, e.g. 3, {9R+9I} dof constrained by unitarity: 4 free parameters, incl. 1 irreducible imaginary part Unitarity conditions V * ji V jk =δ ik for {i=1,k=3} explicit parametrization(wolfenstein): 1!"2/2 " " 3A(#!i$)!" 1!"2/2 "2A "3A(1!#!i$)!"2A 1 irreducibly complex V ub *V ud V cb *V cd (ρ+ιη) V ud V* ub V cd V cb* V tb *V td V cb *V cd = 0 (α) (1 ρ ιη) V td V* tb V cd V cb* "unitarity triangle" (γ) (β)