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arXiv · 0710.2863

First quenched results for the matrix elements of the B_{B_s} mixing parameter in the static limit from tmQCD

F. Palombi·M. Papinutto·C. Pena·H. Wittig
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Abstract

We report on a non-perturbative study of the scale-dependent renormalization factors of a multiplicatively renormalizable basis of Delta B=2 parity-odd four-fermion operators in quenched lattice QCD. We also present some preliminary results of the matrix elements related to the mixing parameter of the B_s-meson. In our lattice formulation, the heavy quark is treated in the static approximation, while the strange one belongs to a doublet of twisted mass fermions at full twist, i.e. with twist angle alpha=pi/2. In this framework, the parity-even Delta B=2 four-fermion operators responsible for the mixing are rotated onto a linear combination of parity-odd operators in the above-mentioned basis. Their physical matrix elements between static B_s-mesons are extracted from lattice correlators with Schroedinger functional boundary conditions. We observe a suppression of excited state contributions to the B_{B_s} mixing parameter and speculate about possible explanations.

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F. Palombi, M. Papinutto, C. Pena, H. Wittig. 2007-10-15. First quenched results for the matrix elements of the B_{B_s} mixing parameter in the static limit from tmQCD. https://arxiv.org/abs/0710.2863

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