Wednesday, September 19, 2012

1209.3821 (Alexander A. Penin et al.)

Nonrelativistic effective field theory of unstable top    [PDF]

Alexander A. Penin, Jan H. Piclum
We develop a new nonrelativistic effective field theory of $\rho$NRQCD [1] to describe the finite lifetime effects in the threshold production of top quark-antiquark pairs. The theory is based on the expansion in a parameter $\rho=1-m_W/m_t$ characterizing the dynamics of the top-quark decay. Within this framework we compute the nonresonant contribution to the total cross section of the top quark-antiquark threshold production in electron-positron annihilation up to the next-to-next-to-leading order. Our method naturally resolves the problem of spurious divergences in the analysis of the unstable top production.
View original: http://arxiv.org/abs/1209.3821

No comments:

Post a Comment