Simultaneous Monte Carlo analysis of parton densities and fragmentation functions

In this study, we present continuum limit results for the unpolarized parton distribution function of the nucleon computed in lattice QCD. This study is the first continuum limit using the pseudo-PDF approach with Short Distance Factorization for factorizing lattice QCD calculable matrix elements. Our findings are also compared with the pertinent phenomenological determinations. Inter alia, we are employing the summation Generalized Eigenvalue Problem (sGEVP) technique in order to optimize our control over the excited state contamination which can be one of the most serious systematic errors in this type of calculations. A crucial novel ingredient of our analysis is the parameterization of systematic errors using Jacobi polynomials to characterize and remove both lattice spacing and higher twist contaminations, as well as the leading twist distribution. This method can be expanded in further studies to remove all other systematic errors.

Section: Parameterization Of Unknown Functionsmentioning

confidence: 99%

Section: Comparison With Global Fitsmentioning

confidence: 99%

Section: Comparison With Global Fitsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

The continuum and leading twist limits of parton distribution functions in lattice QCD

Karpie

Orginos

Radyushkin

et al. 2021

“…Analyses such as [53] suggest that future electron-JHEP08(2021)034 ion collider SIDIS data will have a remarkable impact on the kaon fragmentation functions. On the other hand, it is also argued that in order to use the future rich information of the high precision SIDIS data to extract parton and fragmentation distribution functions with reliable uncertainties, a simultaneous fitting of PDFs and FFs is needed in order to disentangle the highly correlated set of parameters describing them [54][55][56]. In fact, traditional methods of global fitting of FFs using SIDIS data fix a specific PDF set as a baseline and account for their error by propagating them into the FFs themselves.…”

Section: Updating the Pdfs With Pseudo Datamentioning

confidence: 99%

Determining the helicity structure of the nucleon at the Electron Ion Collider in China

Anderle

Hou

Xing

et al. 2021

Understanding how sea quarks behave inside a nucleon is one of the most important physics goals of the proposed Electron-Ion Collider in China (EicC), which is designed to have a 3.5 GeV polarized electron beam (80% polarization) colliding with a 20 GeV polarized proton beam (70% polarization) at instantaneous luminosity of 2 × 1033cm−2s−1. A specific topic at EicC is to understand the polarization of individual quarks inside a longitudinally polarized nucleon. The potential of various future EicC data, including the inclusive and semi-inclusive deep inelastic scattering data from both doubly polarized electron-proton and electron-3He collisions, to reduce the uncertainties of parton helicity distributions is explored at the next-to-leading order in QCD, using the Error PDF Updating Method Package (ePump) which is based on the Hessian profiling method. We show that the semi-inclusive data are well able to provide good separation between flavour distributions, and to constrain their uncertainties in the x > 0.005 region, especially when electron-3He collisions, acting as effective electron-neutron collisions, are taken into account. To enable this study, we have generated a Hessian representation of the DSSV14 set of PDF replicas, named DSSV14H PDFs.

A formalism for extracting track functions from jet measurements

Lee,

Moult,

Ringer

et al. 2024

The continued success of the jet substructure program will require widespread use of tracking information to enable increasingly precise measurements of a broader class of observables. The recent reformulation of jet substructure in terms of energy correlators has simplified the incorporation of universal non-perturbative matrix elements, so called “track functions”, in jet substructure calculations. These advances make it timely to understand how these universal non-perturbative functions can be extracted from hadron collider data, which is complicated by the use jet algorithms. In this paper we introduce a new class of jet functions, which we call (semi-inclusive) track jet functions, which describe measurements of the track energy fraction in identified jets. These track jet functions can be matched onto the universal track functions, with perturbatively calculable matching coefficients that incorporate the jet algorithm dependence. We perform this matching, and present phenomenological results for the charged energy fraction in jets at the LHC and EIC/HERA at collinear next-to-leading logarithmic accuracy. We show that higher moments of the charged energy fraction directly exhibit non-linear Lorentzian renormalization group flows, allowing the study of these flows with collider data. Our factorization theorem enables the extraction of universal track functions from jet measurements, opening the door to their use for a precision jet substructure program.