{"@context":"http://schema.org","@id":"https://doi.org/10.17182/hepdata.153414.v2","@reverse":{"isBasedOn":[{"@type":"ScholarlyArticle","identifier":{"@type":"PropertyValue","propertyID":"URL","value":"https://inspirehep.net/literature/2799639"}},{"@id":"https://doi.org/10.1016/j.physletb.2025.139368","@type":"JournalArticle"}]},"@type":"Dataset","additionalType":"Collection","author":{"@type":"Organization","name":"GlueX Collaboration"},"creator":{"@type":"Organization","name":"GlueX Collaboration"},"datePublished":"2024","description":"We measure the spin-density matrix elements (SDMEs) of the $\\Delta^{++}(1232)$ in the photoproduction reaction $\\gamma p \\to \\pi^-\\Delta^{++}(1232)$ with the GlueX experiment in Hall D at Jefferson Lab. The measurement uses a linearly--polarized photon beam with energies from $8.2$ to $8.8$~GeV and the statistical precision of the SDMEs exceeds the previous measurement by three orders of magnitude for the momentum transfer squared region below $1.4$ GeV$^2$. The data are sensitive to the previously undetermined relative sign between couplings in existing Regge-exchange models. Linear combinations of the extracted SDMEs allow for a decomposition into natural and unnatural--exchange amplitudes. We find that the unnatural exchange plays an important role in the low momentum transfer region.","hasPart":[{"@id":"https://doi.org/10.17182/hepdata.153414.v2/t1","@type":"Dataset","description":"Spin-density matrix elements for the photoproduction of $\\Delta(1232)^{++}$ in the Gottfried-Jackson system. The first uncertainty is statistical, the second systematic.","name":"Delta^{++}(1232) Spin Density Matrix Elements"}],"identifier":[{"@type":"PropertyValue","propertyID":"HEPDataRecord","value":"https://www.hepdata.net/record/ins2799639?version=2"},{"@type":"PropertyValue","propertyID":"HEPDataRecordAlt","value":"https://www.hepdata.net/record/153414"}],"inLanguage":"en","name":"Measurement of Spin-Density Matrix Elements in $\\Delta^{++}(1232)$ photoproduction","provider":{"@type":"Organization","name":"HEPData"},"publisher":{"@type":"Organization","name":"HEPData"},"url":"https://www.hepdata.net/record/ins2799639?version=2","version":2}