Strange and Anti-strange Sea Distributions from Neutrino-Nucleon Deep Inelastic Scattering

TL;DR

This paper presents a detailed QCD analysis of strange and anti-strange quark distributions in the nucleon, using neutrino and anti-neutrino dimuon data, and finds a slightly softer strange sea with negligible asymmetry.

Contribution

It provides the first comprehensive fit of strange sea distributions incorporating multiple experimental data sources and constrains the asymmetry between strange and anti-strange quarks.

Findings

Strange sea suppression factor $\,\kappa(20\text{ GeV}^2)=0.62\pm0.04$

Strange and anti-strange asymmetry consistent with zero

The total strange sea distribution is slightly softer than the non-strange sea.

Abstract

We perform QCD fit of the nucleon strange and anti-strange sea distributions to the neutrino and anti-neutrino dimuon data by the CCFR and NuTeV collaborations, supplemented by the inclusive charged lepton-nucleon Deep Inelastic Scattering (DIS) and Drell-Yan data. The effective semi-leptonic charmed-hadron branching ratio is constrained from the inclusive charmed hadron measurements performed by the FNAL-E531 and CHORUS neutrino emulsion experiments as $B_\mu=(8.8\pm0.5)%$. We obtain a strange sea suppression factor {$\kappa(20 {\rm GeV}^2)=0.62\pm0.04({\rm exp.})\pm0.03({\rm QCD})$}. An $x$-distribution of total strange sea obtained in the fit is slightly softer than the non-strange sea, and an asymmetry between strange and anti-strange quark distributions is consistent with zero (integrated over $x$ it is equal to {$0.0013\pm 0.0009({\rm exp.}) \pm 0.0002({\rm QCD})$ at the scale of $20 {\rm GeV^2}$}).