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H b and other  (5S) results at Belle D. Santel Rencontres de Blois June 1, 2011 1.Introduction to h b and  (5S) 2.Search for the h b 3. Observation of.

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Presentation on theme: "H b and other  (5S) results at Belle D. Santel Rencontres de Blois June 1, 2011 1.Introduction to h b and  (5S) 2.Search for the h b 3. Observation of."— Presentation transcript:

1 h b and other  (5S) results at Belle D. Santel Rencontres de Blois June 1, Introduction to h b and  (5S) 2.Search for the h b 3. Observation of the Z b 1.  (5S) →h b (nP)  +  - 2.  (5S) →  (nS)  +  - Preliminary Results

2 2  ( 5S )  GeV 2M(B s ) BaBar PRL 102, (2009)  ( 6S )  ( 4S )  (5S)  ( 1S )  ( 2S )  ( 3S )  ( 4S ) 2M(B)  (4S) just above threshold, 96% decays (  (5S)) just above threshold, ~60%, ~20%, few bottomonia Bottomonium ( ) s=1, l =0, J PC =1   n=5 This talk  B studies, CP violation, etc.  B s studies D. Santel, Rencontres de Blois 2011

3 KEKb Tsukuba, Japan Asymmetric e + e - storage rings Has run at CM energies: – ~9.46 GeV (  (1S), 5.75 fb -1 ) – ~10.02 GeV (  (2S), 25 fb -1 ) – ~10.36 GeV (  (3S), 2.95 fb -1 ) – ~10.58 GeV (  (4S), fb -1 ) Continuum below  (4S), 90 fb -1 ) – ~10.87 GeV (  (5S), fb -1 ) 8.2 GeV 3.6 GeV e + source cavity Integrated Luminosity D. Santel, Rencontres de Blois 2011 Res/E CM (GeV)/lum  (1S): 9.46, 5.75 fb -1  (2S): 10.02, 25 fb -1  (3S): 10.36, 2.95 fb -1  (4S): 10.58, fb -1  (5S): 10.87, fb -1 Off resonance/scan: ~100 fb -1  (2S): 10.02, 14 fb -1  (3S): 10.36, 30 fb -1  (4S): 10.58, 433 fb -1 Off resonance: ~54 fb -1 3

4 International Collaboration: Belle 13 countries, 57 institutes, ~400 collaborators IHEP, Vienna ITEP Kanagawa U. KEK Korea U. Krakow Inst. of Nucl. Phys. Kyoto U. Kyungpook Nat’l U. EPF Lausanne Jozef Stefan Inst. / U. of Ljubljana / U. of Maribor U. of Melbourne BINP Chiba U. U. of Cincinnati Ewha Womans U. Fu-Jen Catholic U. U. of Giessen Gyeongsang Nat’l U. Hanyang U. U. of Hawaii Hiroshima Tech. IHEP, Beijing IHEP, Moscow Nagoya U. Nara Women’s U. National Central U. National Taiwan U. National United U. Nihon Dental College Niigata U. Nova Gorica Osaka U. Osaka City U. Panjab U. Peking U. Princeton U. Riken Saga U. USTC Seoul National U. Shinshu U. Sungkyunkwan U. U. of Sydney Tata Institute Toho U. Tohoku U. Tohuku Gakuin U. U. of Tokyo Tokyo Inst. of Tech. Tokyo Metropolitan U. Tokyo U. of Agri. and Tech. INFN Torino Toyama Nat’l College VPI Yonsei U. 4D. Santel, Rencontres de Blois 2011

5 5 Bottomonia h b : (bb) : S=0 L=1 J PC =1 +  For h c  M = –0.12  0.30 MeV, Expect  M b <  M c _ Expected mass: Spin-weighted average of M  b  M=M measured -M theory : Test of hyperfine interaction Predictions  M~0-4 MeV Evidence for h b seen at BaBar arXiv: Godfrey et al. Phys. Rev. D 66, (2002)  ( 3 2D)  ( 3 1D) CLEO arXiv: v1 D. Santel, Rencontres de Blois 2011

6 6 Puzzles of  (5S) decays PRL100,112001(2008)  (MeV) >10 2 x 1. Anomalous production of  (nS)  +  - 1.Rescattering  (5S)  BB  (nS)  2.Tetraquark  (5S)  T bb  (nS)  3.Exotic resonance Y b near  (5S) analog of Y(4260) resonance with anomalous  (J/   +  - ) Check shapes of R b and  (  ) as function of E CM Hou et al., Phys.Rev.D74:017504,2006 Ali et al. Phys.Rev.Lett.104:162001,2010 Meng et al. Phys.Rev.D78:034022,2008 Possible explanations... Karliner et al. arXiv: v2; Xiang Liu et al. Eur. Phys. J. C (2009) 61: 411–428; Yan-Rui Liu et al. Eur.Phys.J.C56:63-73,2008; N. Brambilla et al, Eur.Phys.J. C71 (2011) 1534; N. Brambilla et al. CERN Yellow Report, CERN , Geneva: CERN, p. D. Santel, Rencontres de Blois 2011

7 7 PRD82,091106R(2010) Energy Scan  [  (nS)  ]/  [  ]  [bb]/  [  ] R b peaks at 10.87,  (  ) peaks at ~1-2fb -1 /point GeV GeV D. Santel, Rencontres de Blois 2011

8 8 reconstructed Search for h b  (5S)  h b (nP)  +  - E  (5S) is given by c.m. energy and boost E  +  - is measured accelerator information Missing mass technique Energy conservation, using known initial and final states h b : No clear exclusive decays D. Santel, Rencontres de Blois 2011

9 9 MM(  +  - ) spectrum 2S  1S 3S  1S  (2S)  (3S) h b (1P) h b (2P)  (1S) Background-subtracted data Raw spectrum Fit Region 1Fit Region 2Fit Region 3 D. Santel, Rencontres de Blois 2011

10 10 Mass measurements h b (1P) 1.62  1.52 MeV/c 2 h b (2P) MeV/c Results, fb -1  M=M measured -M theory : consistent with zero Mizuk arXiv: v1 BaBar evidence: 9902  4  1 MeV  (3S) →  0 h b (1P) →  0  b (1S) arXiv: D. Santel, Rencontres de Blois 2011

11 11 Ratio of production rates Process with spin-flip of heavy quark is not suppressed  (h b  )  O (  (  )) (also high)  Exotic?  Study substructure for h b (1P) for h b (2P) S(h b )= 0  spin-flip no spin-flip = Naive heavy quark theory: spin-flip suppressed as m →   Expect ratio<<1 D. Santel, Rencontres de Blois 2011

12 12  (5S) → h b (nP)  +  - (  2 Fit) 32 bins from 10.4 MeV < MM(  ) < MeV and fit to MM(  +  - ) for each MM(  ) bin Assume J P =1 + for Z b, so use P-Wave BWs and Blatt Weisskopf FFs  (5S) →h b (2P)  +  - similar with binning: MeV < MM(  )<10.72 MeV q 0 = daughter momentum R = 1.6 GeV -1 M(X)=MM(  - ) Clear structure! --all h b are evidently from resonances Look in similar (and cleaner) decays:  (5S)  (nS)  h b (1P)h b (2P) D. Santel, Rencontres de Blois 2011

13 13  (5S) →  (nS)  +  - Dalitz analysis event selection Require:  +  -  +  - Selection using MM(  +  - ) and M(  +  -  +  - )  (1S)  (2S)  (3S) M(  +  -  +  - )~  (5S) Dalitz analysis of  (5S) →  (nS)  Clean exclusive decay:  +  - D. Santel, Rencontres de Blois 2011

14 Signal Selection arXiv: v1 14 Projections along MM(  +  - )  (1S)  (2S)  (3S) Signal Sideband Plot these events: M(  ) 2 vs. M(  +  - ) 2 D. Santel, Rencontres de Blois 2011

15 Dalitz plots 15 Photon conversions  (1S)  (2S)  (3S) Signal Sideband arXiv: v1 D. Santel, Rencontres de Blois 2011

16 Dalitz plots arXiv: v1 16 Photon conversions  (1S)  (2S)  (3S) Signal Sideband D. Santel, Rencontres de Blois 2011

17 Unbinned maximum likelihood fit 17 Fits performed in M 2 (  ) and M 2 (  ) A f0 and A f2 = contributions from f 0 (980) and f 2 (1270). A f0 Flatte, m=950 MeV A f2 Breit Wigner, m=1275 MeV Amplitude/phase floated in  (1S)  fit (strongest potential contribution), fixed to  (1S)  results for other channels Constant=1 D. Santel, Rencontres de Blois 2011

18 Projections of Fits 18 M(  (3S)  max ) M(  (2S)  max )M(  (1S)  max ) arXiv: v1 D. Santel, Rencontres de Blois 2011

19 19 Projections of Fits M(  (3S)  max ) M(  (2S)  max )M(  (1S)  max ) arXiv: v1

20 charged tetraquark/di-meson candidate For Q=c: Z(4430): Seen at Belle in decay to s=1 l =0 +  (ψ(2S)  + ) – B 0 → K - Z + (4430) → K - ψ(2S)  + Analogue for Q=b: "Z b " in decay to +  – Z b → h b   (5S) → Z b  → h b (nP)  +  - – Z b →   (5S) → Z b  →  (nS)  +  - Candidate for Z b Phys.Rev.Lett.100:142001, D. Santel, Rencontres de Blois 2011

21 21 Summary of parameters of charged Z b states Z b (10610) M=  2.0 MeV  =15.6  2.5 MeV Z b (10650) M=  1.5 MeV  =14.4  3.2 MeV [preliminary] *Also fit for angular dependence. Results favor J P =1 + over 1 -, 2 +, 2 - arXiv: v1 Relative phase Z b (10610) to Z b (10650) ~0  for  ~180  for h b  Masses directly above B * B (*) threshold  molecular interpretation favored

22 22 Summary of the Belle results Seen in 5 different final states, parameters are consistent First observation of two charged bottomonium-like resonances Z b (10610) M =  1.7 MeV  = 15.5  2.4 MeV Z b (10650) M =  1.5 MeV  = 14.0  2.8 MeV  Expectation J P =1 + agrees with data; other J P are disfavored.  Amplitude ratio A[Z b (10610)] / A[Z b (10650)] ~1.  Relative phase ~0  for  and ~180  for h b.  Explains why h b  is unsuppressed relative to . First observation of h b (1P) and h b (2P) Masses consistent with CoG of  bJ states arXiv: arXiv: v1 Preliminary D. Santel, Rencontres de Blois 2011

23 23D. Santel, Rencontres de Blois 2011

24 24 Fit Results Five modes with consistent masses for both "Z b " resonances. D. Santel, Rencontres de Blois 2011

25 arXiv: v1 25 Systematics  (1S)/  (2S)/  (3S) h b (1P)/h b (2P) D. Santel, Rencontres de Blois 2011

26 Angular dependence arXiv: v1 26 Fits performed for 1+, 1-, 2+, 2- spin possibilities 1+ least disfavored for hypotheses with J  2. Probabilities at which other hypotheses are relatively disfavored: ( ) Caveats – Non-resonant component approximate – Neglect mutual cross-feed from two Z b states D. Santel, Rencontres de Blois 2011

27 27 Z b (10610)  (2S)   (3S) 

28 D. Santel, Rencontres de Blois Z b (10650)  (2S)   (3S) 

29 29 : good quality, positively identified Continuum events have jet-like shape  cut on R2<0.3 R2 = ratio of Fox-Wolfram moments +-+- Simple selection for h b : “blind analysis” D. Santel, Rencontres de Blois 2011

30 30  (3S) →  0 h b (1P) →  0   b (1S) arXiv:  h b also seen at BaBar M recoil (  0 ) D. Santel, Rencontres de Blois 2011

31 31D. Santel, Rencontres de Blois 2011


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