B-meson decay constants and B −B0-mixing with domain-wall light and relativistic heavy quarks

We propose to continue and finish our determination of the B-meson leptonic decay constants fBd and fBs , the B−B0 mixing matrix elements, and their ratio, ξ ≡ fBs √ BBs/fBd √ BBd , on the 2+1 flavor dynamical domain-wall fermion gauge field configurations generated by the LHP, RBC, and UKQCD Collaborations. Using the relativistic heavy quark action we expect to obtain precise results which will place strong constraints on the CKM unitarity triangle fits. In particular ξ provides an important constraint on the apex of the CKM triangle and was therefore highlighted as a key goal in flavor physics in the USQCD Collaboration’s 2007 white paper. Our calculation will provide an independent and valuable crosscheck of the results by HPQCD and Fermilab/MILC who both use the same set of gauge field configurations. We request the equivalent of 10.4 million jpsi core-hours on the Fermilab clusters plus 28.2 Tbytes of tape storage (the equivalent of ∼ 76000 jpsi core-hours) and 0.25 Tbytes of disk storage (the equivalent of ∼ 6700 jpsi node-hours) for this project.