Nucleon and pion structure with lattice QCD simulations at physical value of the pion mass

Abdel-Rehim, A.; Alexandrou, C.; Constantinou, M.; Dimopoulos, P.; Frezzotti, R.; Hadjiyiannakou, K.; Jansen, K.; Kallidonis, Ch.; Kostrzewa, B.; Koutsou, G.; Mangin-Brinet, M.; Oehm, M.; Rossi, G. C.; Urbach, C.; Wenger, Urs (2015). Nucleon and pion structure with lattice QCD simulations at physical value of the pion mass. Physical review. D - particles, fields, gravitation, and cosmology, 92(11), p. 114513. American Physical Society 10.1103/PhysRevD.92.114513

[img] Text
PhysRevD.92.114513.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (2MB) | Request a copy
[img]
Preview
Text
1507.04936v3.pdf - Submitted Version
Available under License Publisher holds Copyright.

Download (1MB) | Preview

We present results on the nucleon scalar, axial, and tensor charges as well as on the momentum fraction, and the helicity and transversity moments. The pion momentum fraction is also presented. The computation of these key observables is carried out using lattice QCD simulations at a physical value of the pion mass. The evaluation is based on gauge configurations generated with two degenerate sea quarks of twisted mass fermions with a clover term. We investigate excited states contributions with the nucleon quantum numbers by analyzing three sink-source time separations. We find that, for the scalar charge, excited states contribute significantly and to a less degree to the nucleon momentum fraction and helicity moment. Our result for the nucleon axial charge agrees with the experimental value. Furthermore, we predict a value of 1.027(62) in the MS¯¯¯¯¯ scheme at 2 GeV for the isovector nucleon tensor charge directly at the physical point. The pion momentum fraction is found to be ⟨x⟩π±u−d=0.214(15)(+12−9) in the MS¯¯¯¯¯ at 2 GeV.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)
08 Faculty of Science > Institute of Theoretical Physics

UniBE Contributor:

Wenger, Urs

Subjects:

500 Science > 530 Physics

ISSN:

1550-7998

Publisher:

American Physical Society

Language:

English

Submitter:

Esther Fiechter

Date Deposited:

16 Feb 2016 16:26

Last Modified:

19 Feb 2016 00:55

Publisher DOI:

10.1103/PhysRevD.92.114513

ArXiv ID:

1507.04936v3

BORIS DOI:

10.7892/boris.75459

URI:

https://boris.unibe.ch/id/eprint/75459

Actions (login required)

Edit item Edit item
Provide Feedback