18–22 May 2015
Wayne State University
US/Eastern timezone

A New Dynamical Picture for Production and Decay of the XYZ Mesons

18 May 2015, 14:30
30m
B/C, McGregor (Wayne State University)

B/C, McGregor

Wayne State University

Wayne State University Detroit, MI 48201

Speaker

Prof. Richard Lebed (Arizona State University)

Description

I introduce an entirely new dynamical description for tetraquark mesons, based upon the competing effects of the strong attraction between quarks in a diquark, and the inability of the diquark to hadronize on its own due to being a color nonsinglet. This mechanism naturally explains, for example, the strong preference of the Z(4475) to decay to psi(2S) rather than the J/psi, the existence of a state Y(4630) that decays to Lambda_c baryon pairs, and why some but not all exotics lie near hadronic thresholds. Owing to high-energy constituent counting rules, the four-quark nature of the states produces major changes to both the high-s scaling of cross sections for producing such states and to the potency of the cusp effect of attracting resonances to pair-production thresholds.

Primary author

Prof. Richard Lebed (Arizona State University)

Presentation materials