πγ → ππ transition and the ρ radiative decay width from lattice QCD
We report a lattice QCD determination of the πγ→ππ transition amplitude for the P-wave, I=1 two-pion final state, as a function of the photon virtuality and ππ invariant mass. The calculation was performed with 2+1 flavors of clover fermions at a pion mass of approximately 320 MeV, on a 32^{3}×96 la...
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| Format: | Article |
| Language: | English |
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American Physical Society
2020
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| Online Access: | https://hdl.handle.net/1721.1/124797 |
| _version_ | 1826205641724657664 |
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| author | Negele, John W. |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Negele, John W. |
| author_sort | Negele, John W. |
| collection | MIT |
| description | We report a lattice QCD determination of the πγ→ππ transition amplitude for the P-wave, I=1 two-pion final state, as a function of the photon virtuality and ππ invariant mass. The calculation was performed with 2+1 flavors of clover fermions at a pion mass of approximately 320 MeV, on a 32^{3}×96 lattice with L≈3.6 fm. We construct the necessary correlation functions using a combination of smeared forward, sequential and stochastic propagators, and determine the finite-volume matrix elements for all ππ momenta up to |P[over →]|=sqrt[3]2π/L and all associated irreducible representations. In the mapping of the finite-volume to infinite-volume matrix elements using the Lellouch-Lüscher factor, we consider two different parametrizations of the ππ scattering phase shift. We fit the q^{2} and s dependence of the infinite-volume transition amplitude in a model-independent way using series expansions, and compare multiple different truncations of this series. Through analytic continuation to the ρ resonance pole, we also determine the πγ→ρ resonant transition form factor and the ρ meson photocoupling, and obtain |G_{ρπγ}|=0.0802(32)(20). ©2018 |
| first_indexed | 2024-09-23T13:16:36Z |
| format | Article |
| id | mit-1721.1/124797 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T13:16:36Z |
| publishDate | 2020 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1247972022-10-01T14:12:07Z πγ → ππ transition and the ρ radiative decay width from lattice QCD Negele, John W. Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Center for Theoretical Physics We report a lattice QCD determination of the πγ→ππ transition amplitude for the P-wave, I=1 two-pion final state, as a function of the photon virtuality and ππ invariant mass. The calculation was performed with 2+1 flavors of clover fermions at a pion mass of approximately 320 MeV, on a 32^{3}×96 lattice with L≈3.6 fm. We construct the necessary correlation functions using a combination of smeared forward, sequential and stochastic propagators, and determine the finite-volume matrix elements for all ππ momenta up to |P[over →]|=sqrt[3]2π/L and all associated irreducible representations. In the mapping of the finite-volume to infinite-volume matrix elements using the Lellouch-Lüscher factor, we consider two different parametrizations of the ππ scattering phase shift. We fit the q^{2} and s dependence of the infinite-volume transition amplitude in a model-independent way using series expansions, and compare multiple different truncations of this series. Through analytic continuation to the ρ resonance pole, we also determine the πγ→ρ resonant transition form factor and the ρ meson photocoupling, and obtain |G_{ρπγ}|=0.0802(32)(20). ©2018 U.S. Department of Energy Office of Nuclear Physics (grant no. DE-SC-0011090) U.S. Department of Energy Office of Nuclear Physics (grant no. DE-FC02- 06ER41444) 2020-04-22T16:25:42Z 2020-04-22T16:25:42Z 2018-10 2018-08 2018-10-02T18:00:13Z Article http://purl.org/eprint/type/JournalArticle 2470-0010 2470-0029 https://hdl.handle.net/1721.1/124797 Alexandrou, Constantia, et al., "πγ → ππ transition and the ρ radiative decay width from lattice QCD." Physical review D 98 (October 2018): no. 074502 doi 10.1103/PhysRevD.98.074502 ©2018 Author(s) en 10.1103/PhysRevD.98.074502 Physical review D Creative Commons Attribution 3.0 unported license http://creativecommons.org/licenses/by/3.0 application/pdf American Physical Society American Physical Society |
| spellingShingle | Negele, John W. πγ → ππ transition and the ρ radiative decay width from lattice QCD |
| title | πγ → ππ transition and the ρ radiative decay width from lattice QCD |
| title_full | πγ → ππ transition and the ρ radiative decay width from lattice QCD |
| title_fullStr | πγ → ππ transition and the ρ radiative decay width from lattice QCD |
| title_full_unstemmed | πγ → ππ transition and the ρ radiative decay width from lattice QCD |
| title_short | πγ → ππ transition and the ρ radiative decay width from lattice QCD |
| title_sort | πγ ππ transition and the ρ radiative decay width from lattice qcd |
| url | https://hdl.handle.net/1721.1/124797 |
| work_keys_str_mv | AT negelejohnw pgpptransitionandtherradiativedecaywidthfromlatticeqcd |