Dear all,
Tomorrow we have a theory seminar at 2pm in room H331. The speaker is
Michele Della Morte from Mainz. See below for details.
Regards,
Damien George and Mert Aybat.
----
Date/place: Thursday 28th April, 2pm, H331
Speaker: Michele Della Morte (Mainz)
Title: Non-perturbative Heavy Quark Effective Theory on the lattice
The b-quark is too heavy to be treated dynamically on the lattice. Indeed,
in units of nowadays affordable resolutions am_ b >> 1. A theoretically
attractive option is to use effective theories like Heavy Quark Effective
Theory (HQET), which provides the correct asymptotic description of QCD
correlation functions in the limit m_b to infinity. Subleading effects are
described by higher dimensional operators whose coupling constants are
formally O(1/m_b) to the appropriate power. The degrees of freedom in the
effective theory are strongly coupled and therefore a non-perturbative
approach is needed. In addition HQET has to be matched to the full theory,
a step, which must as well be performed non-perturbatively beyond leading
order in 1/m_b.
We have introduced a framework for non-perturbative HQET on the lattice.
In a first step we match HQET and QCD in a small volume (L=0.4 fm). To
make contact with phenomenology the HQET expressions of the relevant
quantities are then evolved to large volume. The essential tools in this
step are the step scaling functions, which we introduce to describe the
effects of a change in the linear size L of the system by a factor two. We
present non-perturbative results at NLO in 1/m_bfor the b-quark mass, the
B_s spectrum and decay constant in the quenched approximation and with two
dynamical flavors. Perspectives on other phenomenologically interesting
quantities (as semileptonic form factors) are also discussed.
_______________________________________________
Theory-wide mailing list
Theory-wide@nikhef.nlhttps://mailman.nikhef.nl/mailman/listinfo/theory-wide