Biomedical subjects

Fyodor Tkachov

Publications and source records attributed to Fyodor Tkachov.

2 recordsLinked to original sources

PubMed2006

Enhancement of hadronic b quark decays.

A class of previously unknown strong-interaction corrections is found to enhance the rate of nonleptonic decays of the quark by 5%-8%. This effect decreases the predicted fraction of semileptonic decays and brings it into fair agreement with experimental results. As well as solving a long-standing puzzle of measurements disagreeing with the standard model prediction, our work suggests a way for future precise studies of nonleptonic quark decays and their application to searching for "new physics."

Journal Article↗

PubMed2004

Heavy-to-light-quark decays with two-loop accuracy.

We present a determination of a new class of three-loop Feynman diagrams describing heavy-to-light transitions. We apply it to find the O(alpha2(s)) corrections to the top quark decay t --> bW and to the distribution of lepton invariant mass in the semileptonic b quark decay b --> ulnu. We also confirm the previously determined total rate of that process as well as the O(alpha2) corrections to the muon lifetime.

Journal Article↗