# Search for V + A current in top quark decay in p anti-p collisions at s**(1/2) = 1.96-TeV

We report an upper limit on the fraction of V+A current, fV+A, in top-quark decays, using approximately 700 pb-1 of p[overline p] collisions at sqrt(s)=1.96 TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t-->Wb-->[script-l]nub (where [script-l]=e or µ), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. We determine fV+A=-0.06$\pm$0.25 given a top-quark mass of 175 GeV/c2. We set an upper limit on fV+A of 0.29 at the 95\% confidence level, an improvement by a factor of 2 on the previous best direct limit.

### Cited Authors

• Abulencia, ; A, ; others,

• 2007

### Published In

• Phys. Rev. Lett.

• 98 /

• 072001 -

• 17359018