Parton distributions with higher twist and jet power corrections

TL;DR

This paper develops a comprehensive method to include higher twist and power corrections in parton distribution functions, improving the accuracy of predictions for LHC processes and related observables.

Contribution

It introduces a novel methodology using the theory covariance formalism to quantify and incorporate higher twist and linear power corrections into global PDF fits.

Findings

Reduced sensitivity to low-x DIS data and low-pT jet data due to power corrections.

Improved description of experimental data with smaller uncertainties.

Small but significant effects on Higgs production and alpha_s determination.

Abstract

We present a global determination of parton distribution functions (PDFs) that accounts for higher twist corrections in deep-inelastic scattering (DIS) and linear power corrections for single inclusive jet and dijet production data from the LHC. We determine these corrections and their associated correlated uncertainties using a methodology based on the theory covariance formalism, previously used to account for nuclear uncertainties and missing higher order uncertainties (MHOUs) in global PDF determinations. We then study the impact of the power corrections on the extracted PDFs, and demonstrate an improved description of the data due to a reduced sensitivity to DIS data in the low-$x$ region where higher twist uncertainties are relatively large, and a reduced sensitivity to single inclusive jet data at relatively low $p_T$, where linear power corrections can be significant. Finally, we assess the impact of power corrections on observables relevant to LHC phenomenology, including Higgs production via gluon fusion, and the determination of $\alpha_s$. We find that these effects, while small, can be significant, improving perturbative convergence.