Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This study measures D*+/- meson production within jets in proton-proton collisions at 7 TeV using the ATLAS detector, revealing discrepancies with Monte Carlo predictions at low momentum fractions.

Contribution

It provides the first detailed measurement of D*+/- mesons in jets at 7 TeV, highlighting limitations of existing simulation models at low z values.

Findings

Measured production rate of D*+/- mesons in jets

Discrepancies between data and Monte Carlo at low z

Results constrain models of heavy-flavor production in jets

Abstract

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.