1 / 10

Four quark state — a nature interpretation of the D s (2632)

Four quark state — a nature interpretation of the D s (2632). Yu-Qi Chen & Xue-Quan Li hep-ph/0407062. Outline. Selex experiments Four quark state interpretation of Ds(2632) Ds(2317), Ds(2460) Predictions Outlook. SELEX experiments.

kyria
Download Presentation

Four quark state — a nature interpretation of the D s (2632)

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. Four quark state — a nature interpretation of the Ds(2632) Yu-Qi Chen & Xue-Quan Li hep-ph/0407062 Outline • Selex experiments • Four quark state interpretation ofDs(2632) • Ds(2317), Ds(2460) • Predictions • Outlook

  2. SELEX experiments Selex hep-ex/0406045 Fixed target at Fermilab 600 GeV Σ- +π-

  3. 2. Four-quark state interpretation ofDs(2632) Possible interpretations • cs excited state • Ds(2632) →DKOZI allowed • expect to have large decay width • csg, csgg hybrid state • mass too large ? decay width large? • 4 quark state - nature

  4. 4-quark interpretation Flavor SU(3) partner Spin excitation molecule repulsive diaquark - antidiaquark repulsive Possible color configurations

  5. Decay modes suppression • s s quark final state destructive interference like D+ decay • . • ss annihilation higher order process • color match

  6. 3. Ds(2317), Ds(2460) Surprising mass relations In heavy quark chiral effective theory are chiral partner of Ds(1996), D*s(2112) Ds(2317), Ds(2460) 0+ 1+ 0- 1- Bardeen, Eichten, & Hill Nowak, Rho, & Zahed Mass splittings are given by Godberg-Trieman relation In mc→∞ limit Questions: no such partners of D and D* mesons satisfy this relation

  7. Molecular picture Barnes, Close & Lipkin Beveren & Rupp Cheng & Hou The mass difference DK and D*K threshold 40 MeV are dominated by D*K and DKmolecular states Ds(2317), Ds(2460) Ds(2317), Ds(2460) The relation of the mass differences can be understood in the molecular picture K Mass difference is caused by the spin-flip interaction Suppressed by 1/mc , pseudoscalar meson K is blind to the spin of charm

  8. Decays: below the DK threshold dominated by isospin violated process Electromagnetic decay Belle CLEO Question: molecular state is not so good in explaining the electromagnetic decays

  9. 4. Predictions In the molecular picture, mass is around 2770 MeV 50 MeV deviation is acceptable Main Decay modes

  10. 5. Outlook Ds(2632) as well asDs(2317) ,Ds(2460) are very interesting states BaBar scan from B decay did not see signal Ds(2632) needs confirmation !!!

More Related