Width of exotics from QCD sum rules: Tetraquarks or molecules?

Su Houng Lee, Kenji Morita, Marina Nielsen

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


We investigate the widths of the recently observed charmonium like resonances X(3872), Z(4430), and Z2(4250) using QCD sum rules. Extending previous analyses regarding these states as diquark-antiquark states or molecules of D mesons, we introduce the Breit-Wigner function in the pole term. We find that introducing the width increases the mass at the small Borel window region. Using the operator-product expansion up to dimension 8, we find that the sum rules based on interpolating current with molecular components give a stable Borel curve from which both the masses and widths of these resonances can be well obtained. Thus the QCD sum rule approach strongly favors the molecular description of these states.

Original languageEnglish
Article number076001
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number7
Publication statusPublished - 2008 Oct 7

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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