Precision Measurement of the Ratio B(t -} Wb)/B(t -} Wq) and Extraction of V(tb)

Abstrakt

We present a measurement of the ratio of top quark branching fractions R = B(t -} Wb)/B(t -} Wq), where q can be a d, s, or b quark, in the lepton + jets and dilepton t (t) over bar final states. The measurement uses data from 5.4 fb(-1) of p (p) over bar collisions collected with the D0 detector at the Fermilab Tevatron Collider.

We measure R = 0.90 +/- 0.04, and we extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element vertical bar V(tb)vertical bar as vertical bar V(tb)vertical bar = 0.95 +/- 0.02, assuming unitarity of the 3 x 3 CKM matrix.

Klíčová slova

• Top quark
• CKM matrix
• V(tb)