DPF 2011

Measurement of the W boson helicity in top quark decays using 5.4 fb-1 of ppbar collision data

12 Aug 2011, 09:20

20m

553 (Rhode Island Convention Center)

Parallel contribution Top Quark Physics Top Quark Physics

Speaker

Amitabha Das (University of Arizona)

Description

We present a measurement of the helicity of the W boson produced in top quark decays using $t\overline{t}$ ~decays in the $\ell +$jets and dilepton final states selected from a sample of 5.4 fb${}^{-1}$ of collisions recorded using the D0 detector at the Fermilab Tevatron $p\overline{p}$ collider. We measure the fractions of longitudinal and right-handed $W$ bosons to be $f_0=0.669\pm 0.102[\pm 0.078\text{ (stat.)}\pm 0.065\text{ (syst.)}]$ and $f_{+}=0.023\pm 0.053[\pm 0.041\text{ (stat.)}\pm 0.034\text{ (syst.)}]$, respectively. This result is consistent at the 98\% level with the standard model. A measurement with $f_0$ fixed to the value from the standard model yields $f_{+}=0.010\pm 0.037[\pm 0.022\text{ (stat.)}\pm 0.030\text{ (syst.). }]$

Presentation materials

Slides

DPF_AmitabhaDas_Aug12.pdf