Document Type

Dissertation

Date of Degree

Spring 2016

Degree Name

PhD (Doctor of Philosophy)

Degree In

Physics

First Advisor

Jane Nachtman

Abstract

This dissertation presents muon charge asymmetry, fiducial differential cross section and CMS single muon trigger efficiency measurements as a function of muon pseudorapidity for inclusive W→μν events produced in proton-proton collisions at the LHC. The data were recorded by the CMS detector at a center-of-mass energy of 8 TeV and correspond to an integrated luminosity of 18.8 fb-1. Several comparisons are performed to cross-check the experimental results. Muon efficiency measurements are compared to estimated values from Monte Carlo simulations and reference values recommended by CMS physics object groups. The differential cross section and the charge asymmetry measurements are compared to theoretical predictions based on next-to-leading order and next-to-next-to-leading order QCD calculations with different PDF models. Inputs from the charge asymmetry and the differential cross section measurements for the determination of the next generation of PDF sets are expected to bring different predictions closer together and aid in reducing PDF uncertainties. The impact of the charge asymmetry on PDFs has been investigated by putting the asymmetry results into a QCD analysis at next-to-leading order and next-to-next-leading order with inclusive deep-inelastic scattering data from HERA. Significant improvement of the accuracy on the valence-quark distributions is observed. This measurement is recommended for more accurate constraints in future PDF determinations. More precise measurements of PDFs will improve LHC predictions.

Public Abstract

The differential cross section and charge asymmetry for inclusive pp to W + X to μν + X production at √s = 8 TeV are measured as a function of muon pseudorapidity. The data sample corresponds to an integrated luminosity of 18.8 inverse-femtobarns recorded with the CMS detector at the LHC. All observed results are compared with NLO and NNLO QCD predictions. These observed results provide important constraints on the parton distribution functions of the proton.

Keywords

publicabstract, Charge Asymetry, differential cross section, experimental high energy, Parton distribution functions, QCD predictions, W boson production

Pages

xvii, 148

Bibliography

144-148

Copyright

Copyright 2016 Hasan Ogul

Included in

Physics Commons

Share

COinS