Constraints on parton distribution functions and extraction of the strong coupling constant from the inclusive jet cross section in pp collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports a precise measurement of the inclusive jet cross section in proton-proton collisions at 7 TeV, providing constraints on proton parton distribution functions and determining the strong coupling constant at the Z boson mass.

Contribution

It presents the first constraints on proton PDFs and the strong coupling constant from CMS jet data at 7 TeV, using NLO QCD predictions with electroweak corrections.

Findings

Strong constraints on gluon density at high momentum fractions.

Determination of alpha_S(MZ) = 0.1185 with uncertainties.

Agreement with the world average of the strong coupling constant.

Abstract

The inclusive jet cross section for proton-proton collisions at a centre-of-mass energy of 7 TeV was measured by the CMS Collaboration at the LHC with data corresponding to an integrated luminosity of 5.0 inverse femtobarns. The measurement covers a phase space up to 2 TeV in jet transverse momentum and 2.5 in absolute jet rapidity. The statistical precision of these data leads to stringent constraints on the parton distribution functions of the proton. The data provide important input for the gluon density at high fractions of the proton momentum and for the strong coupling constant at large energy scales. Using predictions from perturbative quantum chromodynamics at next-to-leading order, complemented with electroweak corrections, the constraining power of these data is investigated and the strong coupling constant at the Z boson mass M[Z] is determined to be alpha[S(M[Z])} = 0.1185 +/- 0.0019 (exp) +0.0060 -0.0037 (theo), which is in agreement with the world average.