[InlineMediaObject not available: see fulltext.]On the computation of hadron-to-hadron transition matrix elements in lattice QCD
Abstract
We discuss the accurate determination of matrix elements < f | ĥ w| i> where neither | i> nor | f> is the vacuum state and ĥ w is some operator. Using solutions of the Generalized Eigenvalue Problem (GEVP) we construct estimators for matrix elements which converge rapidly as a function of the Euclidean time separations involved. | i> and | f> may be either the ground state in a given hadron channel or an excited state. Apart from a model calculation, the estimators are demonstrated to work well for the computation of the B* Bπ-coupling in the quenched approximation. They are also compared to a standard ratio as well as to the "summed ratio method" of [1-3]. In the model, we also illustrate the ordinary use of the GEVP for energy levels.
- Publication:
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Journal of High Energy Physics
- Pub Date:
- January 2012
- DOI:
- 10.1007/JHEP01(2012)140
- arXiv:
- arXiv:1108.3774
- Bibcode:
- 2012JHEP...01..140B
- Keywords:
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- Lattice QCD;
- B-Physics;
- QCD;
- High Energy Physics - Lattice
- E-Print:
- 22 pages including 10 figures