The SMC Experiment: New Data on the Deuteron from the 1994 Run

TL;DR

This paper presents new polarized deep inelastic scattering data on the deuteron from the 1994 SMC run, extending kinematic coverage, reducing errors, and analyzing nucleon spin contributions and semi-inclusive asymmetries.

Contribution

It provides the first moment of the spin-dependent structure function, evaluates the Bjorken sum rule using SMC data alone, and introduces semi-inclusive asymmetry analysis for the first time.

Findings

Extended kinematic range with reduced errors

First moment of the spin structure function measured

Preliminary semi-inclusive asymmetry results obtained

Abstract

An overview of the SMC data taking and the polarized deep inelastic scattering experiment is given. The new data on the deuteron extend the kinematic range and have considerably reduced statistical and systematic errors. The evaluation of the first moment of the spin dependent structure function is presented and the result for the Bjorken sum rule from SMC data alone is given. The spin contribution of the quarks to the spin of the nucleon is obtained with information from weak decays of baryons. In a new polarized semi-inclusive analysis the asymmetry of the difference between the number of positive and negative charged hadrons was studied. Preliminary results are shown.