## Abstract

We calculate the quark orbital angular momentum of the nucleon from the quark energy-momentum tensor form factors on the lattice with the quenched approximation. The disconnected insertion is estimated stochastically which employs the Z_{2} noise with an unbiased subtraction. This reduced the error by a factor of 3-4 with negligible overhead. The total quark contribution to the proton spin is found to be 0.30±0.07. From this and the quark spin content we deduce the quark orbital angular momentum to be 0.17±0.06 which is ∼34% of the proton spin. We further predict that the gluon angular momentum is 0.20±0.07; i.e., ∼40% of the proton spin is due to the glue.

Original language | English |
---|---|

Article number | 114504 |

Pages (from-to) | 1-5 |

Number of pages | 5 |

Journal | Physical review D |

Volume | 62 |

Issue number | 11 |

DOIs | |

State | Published - Dec 1 2000 |

## ASJC Scopus subject areas

- Nuclear and High Energy Physics