Global QCD analysis of spin PDFs in the proton with high- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>x</mml:mi> </mml:math> and lattice constraints

We perform a comprehensive global QCD analysis of spin-dependent parton distribution functions (PDFs), combining all available data on inclusive and semi-inclusive deep-inelastic scattering (DIS), as well as inclusive weak boson and jet production in polarized <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi>p</a:mi> <a:mi>p</a:mi> </a:math> collisions, simultaneously extracting spin-averaged PDFs and fragmentation functions. Including recent Jefferson Lab DIS data at high <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mi>x</c:mi> </c:math> , together with subleading power corrections to the leading-twist framework, allows us to verify the stability of the PDFs for <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:msup> <e:mi>W</e:mi> <e:mn>2</e:mn> </e:msup> <e:mo>≥</e:mo> <e:mn>4</e:mn> <e:mtext> </e:mtext> <e:mtext> </e:mtext> <e:msup> <e:mrow> <e:mi>GeV</e:mi> </e:mrow> <e:mrow> <e:mn>2</e:mn> </e:mrow> </e:msup> </e:math> and quantify the uncertainties on the spin structure functions more reliably. We explore the use of new lattice QCD data on gluonic pseudo-Ioffe time distributions, which, together with jet production and high- <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mi>x</g:mi> </g:math> DIS data, improve the constraints on the polarized gluon PDF. The expanded kinematic reach afforded by the data into the high- <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:mi>x</i:mi> </i:math> region allows us to refine the bounds on higher-twist contributions to the spin structure functions, and test the validity of the Bjorken sum rule.