Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD
We describe a procedure for extracting momentum derivatives of nucleon matrix elements on the lattice directly at Q[superscript 2]=0. This is based on the Rome method for computing momentum derivatives of quark propagators. We apply this procedure to extract the nucleon isovector magnetic moment and...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2018
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| Online Access: | http://hdl.handle.net/1721.1/114688 https://orcid.org/0000-0002-5713-0039 |
| _version_ | 1826201943608918016 |
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| author | Hasan, Nesreen Green, Jeremy Meinel, Stefan Engelhardt, Michael Krieg, Stefan Syritsyn, Sergey Pochinsky, Andrew Negele, John W. |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Hasan, Nesreen Green, Jeremy Meinel, Stefan Engelhardt, Michael Krieg, Stefan Syritsyn, Sergey Pochinsky, Andrew Negele, John W. |
| author_sort | Hasan, Nesreen |
| collection | MIT |
| description | We describe a procedure for extracting momentum derivatives of nucleon matrix elements on the lattice directly at Q[superscript 2]=0. This is based on the Rome method for computing momentum derivatives of quark propagators. We apply this procedure to extract the nucleon isovector magnetic moment and charge radius as well as the isovector induced pseudoscalar form factor at Q[superscript 2]=0 and the axial radius. For comparison, we also determine these quantities with the traditional approach of computing the corresponding form factors, i.e. G[superscript v][subscript E](Q[superscript 2]) and Gp[superscript v][subscript M](Q[superscript 2]) for the case of the vector current and G[superscript v][subscript P](Q[superscript 2]) and G[superscript v][subscript A](Q[superscript 2]) for the axial current, at multiple Q[superscript 2] values followed by z-expansion fits. We perform our calculations at the physical pion mass using a 2HEX-smeared Wilson-clover action. To control the effects of excited-state contamination, the calculations were done at three source-sink separations and the summation method was used. The derivative method produces results consistent with those from the traditional approach but with larger statistical uncertainties especially for the isovector charge and axial radii. |
| first_indexed | 2024-09-23T11:59:26Z |
| format | Article |
| id | mit-1721.1/114688 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T11:59:26Z |
| publishDate | 2018 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1146882023-02-26T04:50:33Z Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD Hasan, Nesreen Green, Jeremy Meinel, Stefan Engelhardt, Michael Krieg, Stefan Syritsyn, Sergey Pochinsky, Andrew Negele, John W. Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Laboratory for Nuclear Science Negele, John W Pochinsky, Andrew We describe a procedure for extracting momentum derivatives of nucleon matrix elements on the lattice directly at Q[superscript 2]=0. This is based on the Rome method for computing momentum derivatives of quark propagators. We apply this procedure to extract the nucleon isovector magnetic moment and charge radius as well as the isovector induced pseudoscalar form factor at Q[superscript 2]=0 and the axial radius. For comparison, we also determine these quantities with the traditional approach of computing the corresponding form factors, i.e. G[superscript v][subscript E](Q[superscript 2]) and Gp[superscript v][subscript M](Q[superscript 2]) for the case of the vector current and G[superscript v][subscript P](Q[superscript 2]) and G[superscript v][subscript A](Q[superscript 2]) for the axial current, at multiple Q[superscript 2] values followed by z-expansion fits. We perform our calculations at the physical pion mass using a 2HEX-smeared Wilson-clover action. To control the effects of excited-state contamination, the calculations were done at three source-sink separations and the summation method was used. The derivative method produces results consistent with those from the traditional approach but with larger statistical uncertainties especially for the isovector charge and axial radii. United States. Department of Energy. Office of Nuclear Physics (Grant DE-FC02-06ER41444) United States. Department of Energy. Office of Nuclear Physics (Grant DE-SC-0011090) 2018-04-13T13:56:41Z 2018-04-13T13:56:41Z 2018-02 2018-02-10T18:00:25Z Article http://purl.org/eprint/type/JournalArticle 2470-0010 2470-0029 http://hdl.handle.net/1721.1/114688 Hasan, Nesreen, et al. “Computing the Nucleon Charge and Axial Radii Directly at Q[superscript 2] = 0 in Lattice QCD.” Physical Review D, vol. 97, no. 3, Feb. 2018. © 2018 American Physical Society https://orcid.org/0000-0002-5713-0039 en http://dx.doi.org/10.1103/PhysRevD.97.034504 Physical Review D Creative Commons Attribution http://creativecommons.org/licenses/by/3.0 application/pdf American Physical Society American Physical Society |
| spellingShingle | Hasan, Nesreen Green, Jeremy Meinel, Stefan Engelhardt, Michael Krieg, Stefan Syritsyn, Sergey Pochinsky, Andrew Negele, John W. Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD |
| title | Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD |
| title_full | Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD |
| title_fullStr | Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD |
| title_full_unstemmed | Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD |
| title_short | Computing the nucleon charge and axial radii directly at Q[superscript 2] = 0 in lattice QCD |
| title_sort | computing the nucleon charge and axial radii directly at q superscript 2 0 in lattice qcd |
| url | http://hdl.handle.net/1721.1/114688 https://orcid.org/0000-0002-5713-0039 |
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