Precision Computation of fK/fπ from Staggered 2+1+1 Flavor Simulations
Project “Precision computation of fK/fπ from staggered 2+1+1 flavor simulations“ aims at a precision test of the first-row unitarity relation of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. To this end, a team of scientists of the University of Wuppertal and Forschungszentrum Jülich under leadership of Dr. Stephan Duerr computes the ratio fK/fπ of the leptonic decay constants of the kaon and the pion. The computation is from first principles, by solving the relevant equations of motion in the underlying fundamental theory, known as ``quantum chromodynamics'' (QCD). Once the result is in hand, the scientists use it to obtain a precise value of the CKM element |Vus| based on |Vud| which is known very accurately. By combining this with the known element |Vub| the scientists can test whether the relation
|Vud|2 + |Vus|2 + |Vub|2 = 1
holds within errors. Any deviation would signal the presence of new physics in the aforementioned leptonic decays.
Dr. Stephan Duerr
Wuppertal University / IAS/JSC at Forschungszentrum Jülich
D-42119 Wuppertal / D-52425 Jülich