The Flavor Asymmetry of the Light Quark Sea from Semi-inclusive Deep-inelastic Scattering

TL;DR

This paper measures the flavor asymmetry of the light quark sea in the nucleon using semi-inclusive deep-inelastic scattering, revealing a non-zero, x-dependent excess of dbar over ubar quarks in the proton.

Contribution

It provides the first determination of the light quark sea flavor asymmetry from semi-inclusive DIS within specified kinematic ranges.

Findings

dbar-ubar is non-zero and x-dependent

Excess of dbar over ubar in the proton

First measurement in this kinematic range

Abstract

The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02<x<0.3 and 1 GeV^2<Q^2<10 GeV^2, for the first time from semi-inclusive deep-inelastic scattering. The quantity (dbar(x)-ubar(x))/(u(x)-d(x)) is derived from a relationship between the yields of positive and negative pions from unpolarized hydrogen and deuterium targets. The flavor asymmetry dbar-ubar is found to be non-zero and x dependent, showing an excess of dbar over ubar quarks in the proton.