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arXiv · 2009.13061

Flavor decomposition for the proton helicity parton distribution functions

C. Alexandrou·M. Constantinou·K. Hadjiyiannakou·K. Jansen·F. Manigrasso
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Abstract

We present, for the first time, an \textit{ab initio} calculation of the individual up, down and strange quark helicity parton distribution functions for the proton. The calculation is performed within the twisted mass clover-improved fermion formulation of lattice QCD using one ensemble of dynamical up, down, strange and charm quarks with a pion mass of 260 MeV. The lattice matrix elements are non-perturbatively renormalized and the final results are presented in the $\overline{ \rm MS}$ scheme at a scale of 2 GeV. We give results on the $\Delta u^+(x)$ and $\Delta d^+(x)$, including disconnected quark loop contributions, as well as on the $\Delta s^+(x)$. For the latter we achieve unprecedented precision compared to the phenomenological estimates.

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BibTeXRIS

C. Alexandrou, M. Constantinou, K. Hadjiyiannakou, K. Jansen, F. Manigrasso. 2020-09-28. Flavor decomposition for the proton helicity parton distribution functions. https://doi.org/10.1103/physrevlett.126.102003

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