Quark and glue momenta and angular momenta in the proton — A lattice calculation

Quark and glue momenta and angular momenta in the proton — A lattice calculation

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5 Scopus citations

Abstract

We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The calculation is carried out on a 16³ ×24 quenched lattice at β = 6.0 and for Wilson fermions with κ = 0.154,0.155, and 0.1555 which correspond to pion masses at 650, 538, and 478 MeV. The quark loops are calculated with Z₄ noise and signal-to-noise is improved further with unbiased subtractions. The glue operator is comprised of gauge-field tensors constructed from the overlap operator. The u and d quark momentum/angular momentum fraction is 0.66(5)/0.72(5), the strange momentum/angular momentum fraction is 0.024(6)/0.023(7), and that of the glue is 0.31(6)/0.25(8). The orbital angular momenta of the quarks are obtained from subtracting the quark spins from the corresponding angular momentum components. As a result, the quark orbital angular momentum constitutes 0.50(2) of the proton spin, with almost all of it coming from the disconnected insertion. The quark spin carries a fraction 0.25(12) and glue carries a fraction 0.25(8) of the total proton spin.

Original language	English
Journal	Proceedings of Science
Volume	139
State	Published - 2011
Event	29th International Symposium on Lattice Field Theory, Lattice 2011 - Squaw Valley, Lake Tahoe, United States Duration: Jul 10 2011 → Jul 16 2011

Bibliographical note

Publisher Copyright:
© Copyright owned by the author(s).

Funding

This work is partially support by U.S. DOE Grant No. DE-FG05-84ER40154 and the Center for Computational Sciences of the University of Kentucky. The work of M. Deka is partially supported by the Institute of Mathematical Sciences, India.

Funders	Funder number
U.S. DOE NNSA-SSAA
U.S. Department of Energy Oak Ridge National Laboratory U.S. Department of Energy National Science Foundation National Energy Research Scientific Computing Center	DE-FG05-84ER40154
U.S. Department of Energy Oak Ridge National Laboratory U.S. Department of Energy National Science Foundation National Energy Research Scientific Computing Center
University of Kentucky
Institute of Mathematical Sciences India

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Cite this

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title = "Quark and glue momenta and angular momenta in the proton — A lattice calculation",

abstract = "We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The calculation is carried out on a 163 ×24 quenched lattice at β = 6.0 and for Wilson fermions with κ = 0.154,0.155, and 0.1555 which correspond to pion masses at 650, 538, and 478 MeV. The quark loops are calculated with Z4 noise and signal-to-noise is improved further with unbiased subtractions. The glue operator is comprised of gauge-field tensors constructed from the overlap operator. The u and d quark momentum/angular momentum fraction is 0.66(5)/0.72(5), the strange momentum/angular momentum fraction is 0.024(6)/0.023(7), and that of the glue is 0.31(6)/0.25(8). The orbital angular momenta of the quarks are obtained from subtracting the quark spins from the corresponding angular momentum components. As a result, the quark orbital angular momentum constitutes 0.50(2) of the proton spin, with almost all of it coming from the disconnected insertion. The quark spin carries a fraction 0.25(12) and glue carries a fraction 0.25(8) of the total proton spin.",

author = "Liu, \{K. F.\} and M. Deka and T. Doi and Yang, \{Y. B.\} and B. Chakraborty and Y. Chen and Dong, \{S. J.\} and T. Draper and M. Gong and Lin, \{H. W.\} and D. Mankame and N. Mathur and T. Streuer",

note = "Publisher Copyright: {\textcopyright} Copyright owned by the author(s).; 29th International Symposium on Lattice Field Theory, Lattice 2011 ; Conference date: 10-07-2011 Through 16-07-2011",

year = "2011",

language = "English",

volume = "139",

}

TY - JOUR

T1 - Quark and glue momenta and angular momenta in the proton — A lattice calculation

AU - Liu, K. F.

AU - Deka, M.

AU - Doi, T.

AU - Yang, Y. B.

AU - Chakraborty, B.

AU - Chen, Y.

AU - Dong, S. J.

AU - Draper, T.

AU - Gong, M.

AU - Lin, H. W.

AU - Mankame, D.

AU - Mathur, N.

AU - Streuer, T.

PY - 2011

Y1 - 2011

N2 - We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The calculation is carried out on a 163 ×24 quenched lattice at β = 6.0 and for Wilson fermions with κ = 0.154,0.155, and 0.1555 which correspond to pion masses at 650, 538, and 478 MeV. The quark loops are calculated with Z4 noise and signal-to-noise is improved further with unbiased subtractions. The glue operator is comprised of gauge-field tensors constructed from the overlap operator. The u and d quark momentum/angular momentum fraction is 0.66(5)/0.72(5), the strange momentum/angular momentum fraction is 0.024(6)/0.023(7), and that of the glue is 0.31(6)/0.25(8). The orbital angular momenta of the quarks are obtained from subtracting the quark spins from the corresponding angular momentum components. As a result, the quark orbital angular momentum constitutes 0.50(2) of the proton spin, with almost all of it coming from the disconnected insertion. The quark spin carries a fraction 0.25(12) and glue carries a fraction 0.25(8) of the total proton spin.

AB - We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The calculation is carried out on a 163 ×24 quenched lattice at β = 6.0 and for Wilson fermions with κ = 0.154,0.155, and 0.1555 which correspond to pion masses at 650, 538, and 478 MeV. The quark loops are calculated with Z4 noise and signal-to-noise is improved further with unbiased subtractions. The glue operator is comprised of gauge-field tensors constructed from the overlap operator. The u and d quark momentum/angular momentum fraction is 0.66(5)/0.72(5), the strange momentum/angular momentum fraction is 0.024(6)/0.023(7), and that of the glue is 0.31(6)/0.25(8). The orbital angular momenta of the quarks are obtained from subtracting the quark spins from the corresponding angular momentum components. As a result, the quark orbital angular momentum constitutes 0.50(2) of the proton spin, with almost all of it coming from the disconnected insertion. The quark spin carries a fraction 0.25(12) and glue carries a fraction 0.25(8) of the total proton spin.

UR - https://www.scopus.com/pages/publications/85053353121

UR - https://www.scopus.com/inward/citedby.url?scp=85053353121&partnerID=8YFLogxK

M3 - Conference article

AN - SCOPUS:85053353121

VL - 139

JO - Proceedings of Science

JF - Proceedings of Science

T2 - 29th International Symposium on Lattice Field Theory, Lattice 2011

Y2 - 10 July 2011 through 16 July 2011

ER -

Quark and glue momenta and angular momenta in the proton — A lattice calculation

Abstract

Bibliographical note

Funding

ASJC Scopus subject areas

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