1 / 38

Excited Charmonium in e + e - annihilation and B decay

Excited Charmonium in e + e - annihilation and B decay. K-T Chao Peking University QWG Workshop, Beijing, Oct. 12-15, 2004. 1. Double Charm Production in e + e  Annihilation Inclusive J/  cc{bar} production Exclusive J/   C ( C0 (1P),  C (2S), … ) production

hedva
Download Presentation

Excited Charmonium in e + e - annihilation and B decay

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Excited Charmonium in e+e- annihilation and B decay K-T Chao Peking University QWG Workshop, Beijing, Oct. 12-15, 2004

  2. 1. Double Charm Production in e+e Annihilation • Inclusive J/ cc{\bar} production • Exclusive J/ C (C0(1P), C(2S),…) production • Search for excited C0(2P), C(3S)… Has C0(2P) or C(3S) been observed at 3.94GeV in e+e- J/ cc{\bar} by Belle? 2. Charmonium in B exclusive decays with QCD factorization • Predicted rates too small (but infrared safe) for B J/ +K, C+K, C1+K, (3770)+K (with S-D mixing) • Infrared divergences in B C0+K, C2+K , hC +K The role of NRQCD color-octet in exclusive processes?

  3. Double Charm Production in e+e Annihilation INCLUSIVE PRODUCTION : e+e J/cc\bar Theory: via ONE virtual photon Cho-Leibovich (1996) Yuan-Qiao-Chao (1997) Baek-Ko-Lee-Song (1998) • pQCD predicts: cross section at s  10.6 GeV 0.10-0.15pb

  4. Belle data  0.9pb, PRL89(2002)142001 larger than theory by at least 5 times. Higher order relativistic and QCD radiative corrections?

  5. Double Charm Production in e+e Annihilation EXCLUSIVEPROCESS e+e J/ C (C0, C(2S),…) Theory: via ONE virtual photon (Braaten-Lee (2003) PRD67, 054007) (Liu-He-Chao (2003) PLB557, 45) (Hagiwara-Kou-Qiao (2003) PLB570, 39) pQCD prediction smaller again by an order of magnitude than Belle cross section  33 femto-barn for e+eJ/C(decaying to  4 charged)(PRL89, 142001)

  6. Double Charm Production in e+e Annihilation Theory: via TWO photons • Enhanced by photon fragmentation (small photon virtuality 4mc2 s ) • Suppressed by QED over QCD couplings • Exclusive J/ +J/ enhanced (Bodwin-Braaten-Lee, PRL90, 162001), the same order as for J/+ C (but ruled out later by data) • Inclusive J/ cc\bar via two photons prevail over via one photon when s  20GeV (Liu-He-Chao, PRD68, R031501)

  7. Double Charm Production in e+e Annihilation • Annihilation into TWO photons can NOT solve problems for both inclusive and exclusive double charm production • Both data larger than pQCD predictions by about an order of magnitude • Color octet contributions are negligible • pQCD factorization fails(?) • C=+ glueballs misidentified as C (?) (Brodsky et al.) excluded!

  8. Search for excited charmonium states in e+e- annihilation • (Liu, He & Chao, hep-ph/0408141) • Predicted relative production rates seem to be compatible with data (Belle: PRL89(2002)142001; hep-ex/0407009) • See also: ICHEP04/Belle, Pakhlov et al. • In e+e- → J/(cc)res e+e- →(2S)(cc)res • c, c0, c(2S) seen • [c1, c2, J/, (2S) not seen] • Calculate the production cross sections, and Search for excited C0(2P), C(3S)… • Test the production mechanisms • Search for new charmonium states

  9. ICHEP04/Belle, Pakhlov et al. e+e-→ J/(cc)res with L=155 fb-1 • Study recoil mass against J/: Mrecoil((Ecms–EJ/)2–PJ/2)½ • Include all known charmonium states: c, J/, c0, c1, c2, c’, (2S) • Yields for J/, c1, c2, (2S) ~ 0  set UL c, c0, c’ confirmed J/, c1, c2, (2S) not seen

  10. e+e-→(2S)(cc)res • Similar analysis for reconstructed (2S)J/ • Fit to Mrecoil ((2S)) spectrum: • 5.3  observation of sum of c, c0, c’ Similar tendency: c, c0, c’ seen… J/, c1, c2, (2S) not seen

  11. Evidence for new charmonium • The reconstruction and selection procedure is not changed since the first Belle paper • Extend the studied region • No signal of X(3872) • Significant peak at M=3.9400.011 GeV/c2 • N=14833 (4.5) • The width is surprisingly narrow <~ resolution (= 32 MeV)

  12. X(3940) could be C0(2P) or C(3S)…? C0(2P) 0++ mass: consistent with potential model estimate. narrow width: node in wave function may cause suppression for DDbar (see e.g. Eichten et al); but 0++ can not decay to DD*bar. C(3S) 0-+ mass: lower than potential model expected [close or even heavier than (3S) = (4040)] decay: 0-+ can not decay to DD\bar, and the allowed DD*\bar could be suppressed by the node structure--natural explanation for the observed decay width and modes? Unkonw 1++ : if it is C1(2P), why C1(1P) not observed? Another 1++? Is this X(3940) related to the J/ structure at 3940 MeV in B decay? Branching ratio C0(2P) J/seems too large? Width smaller than 90 MeV.

  13. Infrared Divergences in B CJ K and B hCK Decays in QCD Factorization(Song, Chao, Phys.Lett. B568 (2003)127)(Song, Meng, Gao, Chao, Phys.Rev.D69(2003)054009)(Song, Meng, Chao, Eur.Phys.JC36(2004)365) BBNS (Beneke et al.) QCD factorization: • Good for Bpi pi, BD pi. • Problems for Bcharmonium+K

  14. Color transparency, cc-bar small size, viewed as a color (singlet) dipole, factorization might be good? • S-wave: BJ/ K (infrared safe) , but smaller than data by ~ 8 times (Chay-Kim, Cheng-Yang) ; • S-wave: B C K (infrared safe) , but smaller than data by ~ 8 times (Song-Meng-Chao); • P-wave: B CJ K and B hCK , Infrared divergences (due to vertex corrections) in QCD factorization and NRQCD

  15. Z=M2/MB2  4mc 2 /mb2  is the gluon mass for infrared regularization

  16. If usingthe infrared divergence term to estimate the B exclusive decay widthsas in the case of hadronic decay widths: (hc ggg)=5/6  (c1qqg)

  17. Too large branching ratio for BhcK ! New method and ingredients based on NRQCD are expected to remove infrared divergences !

  18. Questions about NRQCD color-octet mechanism Color octet components in charmonium should help, as in the INCLUSIVE B decays, to enhance the decay rates and remove the infrared divergences, but HOW to do it in EXCLUSIVE decays?

  19. Other approach to solve the problems • Rescattering effects by intermediate charmed mesons, B D+DsXco+K (Colangelo-DeFazio-Pham,PLB542(2002)71; PRD69(2004),054023) • LCSR: large for BJ/psi+ K, Xc1+K small for Betac+K, Xco+K (Melic, PRD68(2003)034004) (Wang-Li-Huang, hep-ph/0311296)

More Related