Precision studies of duality in the 't Hooft model
We address the numerical aspects of local quark-hadron duality using the example of the exactly solvable 't Hooft model, two-dimensional QCD with N{sub c}{yields}{infinity}. The primary focus of these studies is the total semileptonic decay widths relevant for extracting |V{sub cb}| and |V{sub ub}|. We compare the exact channel-by-channel sum of exclusive modes to the corresponding rates obtained in the standard 1/m{sub Q} expansion arising from the operator product expansion. An impressive agreement sets in unexpectedly early, immediately after the threshold for the first hadronic excitation in the final state. Yet even at higher energy release it is possible to discern the seeds of duality-violating oscillations. We find the ''small velocity'' sum rules to be exceptionally well saturated already by the first excited state. We also obtain a convincing degree of duality in the differential distributions and in an analogue of R{sub e{sup +}e{sup -}}(s). Finally, we discuss possible lessons for semileptonic decays of actual heavy quarks in QCD.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40205177
- Journal Information:
- Physical Review D, Vol. 62, Issue 9; Other Information: DOI: 10.1103/PhysRevD.62.094011; Othernumber: PRVDAQ000062000009094011000001; 046021PRD; PBD: 1 Nov 2000; ISSN 0556-2821
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
Similar Records
Precision Studies of Duality in the 't Hooft Model
Explicit quark-hadron duality in heavy-light meson weak decays in the {close_quote}t Hooft model