We study the low transverse momentum (pT) distribution of the Z-boson at hadron colliders for pT∼ΛQCD using a factorization and resummation formula derived in the soft-collinear effective theory (SCET). In the region pT∼ΛQCD, new nonperturbative effects arise that cannot be entirely captured by the standard parton distribution functions, and require an additional new nonperturbative transverse momentum function (TMF). The TMF is field-theoretically defined in SCET, fully gauge-invariant, and captures the nonperturbative dynamics that affect the pT-distribution in the region pT∼Λ QCD. The TMF also reduces to the expected perturbative result in the region pTΛQCD. We develop phenomenological models for these TMFs in the nonperturbative region, and discuss in detail fits to Tevatron data in which both experimental and theoretical errors are carefully treated.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Jul 22 2011|
ASJC Scopus subject areas
- Nuclear and High Energy Physics