https://doi.org/10.1140/epjc/s10052-011-1607-4
Regular Article - Theoretical Physics
Sum rule estimate of the subleading non-perturbative contributions to B
s
–
mixing
1
Fachbereich 7 (Physik) Theoretische Physik I, Universität Siegen, Emmy Noether Campus Walter Flex Strasse 3, 57068, Siegen, Germany
2
Institut für Physik (THEP), Johannes Gutenberg-Universität, 55099, Mainz, Germany
3
Institute for Nuclear Research of the Russian Academy of Sciences, 117312, Moscow, Russia
* e-mail: pivovarov@hep.physik.uni-siegen.de
Received:
6
October
2010
Revised:
17
January
2011
Published online:
8
April
2011
We use QCD sum rules to compute the matrix elements of the ΔB=2 operators appearing in the heavy-quark expansion of the width difference of the B s mass eigenstates. The main focus of our analysis is on the subleading operators R 2 and R 3, which appear at next-to-leading order in the 1/m b expansion. The matrix elements of these operators are already essential for precise phenomenology, but their calculation in lattice QCD is lacking and the values given here provide a first estimate of their values. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1–2%.
© Springer-Verlag / Società Italiana di Fisica, 2011