{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/the-i1-pion-pion-scattering-amplitude-and","title":"The $I=1$ pion-pion scattering amplitude and timelike pion form factor from $N_{\\rm f} = 2+1$ lattice QCD","arxiv_id":"1808.05007","date":"2018-08-15","proceeding":null,"authors":["Christian Andersen","John Bulava","Ben Hörz","Colin Morningstar"],"abstract":"The elastic $I=1$ $p$-wave $\\pi\\pi$ scattering amplitude is calculated together with the isovector timelike pion form factor using lattice QCD with $N_{\\rm f}=2+1$ dynamical quark flavors. Wilson clover ensembles generated by the Coordinated Lattice Simulations (CLS) initiative are employed at four lattice spacings down to $a = 0.05\\,\\mathrm{fm}$, several pion masses down to $m_{\\pi} = 200\\,\\mathrm{MeV}$, and spatial volumes of extent $L = 3.1-5.5\\,\\mathrm{fm}$. The set of measurements on these ensembles, which is publicly available, enables an investigation of systematic errors due to the finite lattice spacing and spatial volume. The $\\pi\\pi$ scattering amplitude is fit on each ensemble by a Breit-Wigner resonance lineshape, while the form factor is described better by a thrice-subtracted dispersion relation than the Gounaris-Sakurai parametrization.","url_abs":"http://arxiv.org/abs/1808.05007v1","url_pdf":"http://arxiv.org/pdf/1808.05007v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"the-i1-pion-pion-scattering-amplitude-and","repo_url":"https://github.com/ebatz/jupan","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}