[
    {
        "id": "authors:f20w6-bka71",
        "collection": "authors",
        "collection_id": "f20w6-bka71",
        "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:WORpr60",
        "type": "article",
        "title": "Photoproduction of Neutral Pions at Energies 600 to 800 Mev",
        "author": [
            {
                "family_name": "Worlock",
                "given_name": "R. M.",
                "clpid": "Worlock-R-M"
            }
        ],
        "abstract": "The photoproduction of neutral \u03c0 mesons from hydrogen has been studied at the California Institute of Technology Synchrotron Laboratory by detecting recoil protons from a liquid hydrogen target irradiated by the synchrotron bremsstrahlung beam. The recoil protons were detected by a five-counter telescope. Data were taken at proton laboratory angles of 19\u00b0, 30\u00b0, 40\u00b0, 50\u00b0, and 60\u00b0 at proton energies corresponding to photon energies of 600, 700, and 800 Mev. Angular distribution data are produced at these three energies and fitted with functions of the form: A+Bcos\u03b8\u03c0\u2032+Ccos^2\u03b8\u03c0\u2032. These functions are qualitatively like those at lower energies; B is small and -A/C is roughly 1.25. The total cross section is found to have a minimum at about 600 Mev, being slightly larger at 700 and 800 Mev.",
        "doi": "10.1103/PhysRev.117.537",
        "issn": "0031-899X",
        "publisher": "American Physical Society",
        "publication": "Physical Review",
        "publication_date": "1960-01-15",
        "series_number": "2",
        "volume": "117",
        "issue": "2",
        "pages": "537-543"
    },
    {
        "id": "authors:znmey-3zz79",
        "collection": "authors",
        "collection_id": "znmey-3zz79",
        "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-101018408",
        "type": "article",
        "title": "Photoproduction of Positive Mesons from Hydrogen: Results",
        "author": [
            {
                "family_name": "Bacher",
                "given_name": "R. F.",
                "clpid": "Bacher-R-F"
            },
            {
                "family_name": "Keck",
                "given_name": "J. C.",
                "clpid": "Keck-J-C"
            },
            {
                "family_name": "Peterson",
                "given_name": "V. Z.",
                "clpid": "Peterson-V-Z"
            },
            {
                "family_name": "Teasdale",
                "given_name": "J. G.",
                "clpid": "Teasdale-T-G"
            },
            {
                "family_name": "Tollestrup",
                "given_name": "A. V.",
                "clpid": "Tollestrup-A-V"
            },
            {
                "family_name": "Walker",
                "given_name": "R. L.",
                "clpid": "Walker-R-L"
            },
            {
                "family_name": "Worlock",
                "given_name": "R. M.",
                "clpid": "Worlock-R-M"
            }
        ],
        "abstract": "The center-of-mass differential cross section for photoproduction of positive pions from hydrogen has been measured by the methods described in the two previous abstracts, in the angular range 40\u00b0 to 150\u00b0, for photons from 220 to 475 Mev. (Photon energies refer to the Laboratory System.) Results obtained by the two methods are in essential agreement. At 90\u00b0, d\u03c3/d\u03c9 has a maximum of 2.7 X 10^(-29) cm^2/sterad near 280 Mev and falls by a factor 5 at 450 Mev. The maximum in the excitation curve is even more pronounced at larger angles, but less pronounced at smaller ones. At 40\u00b0 (c.m.) the peak occurs near 350 Mev and at 450 Mev the cross section has decreased only to 0.7 the, peak value. Angular distributions in the center-of-mass system show a marked assymetry about 90\u00b0, which changes character from low energy to high. Below 325 Mev, there ii a backward maximum, whereas above 375 Mev, there is a forward maximum. The total cross section reaches a maximum near 290 Mev and decreases by about a factor 3 at 450 Mev. The results below 300 Mev agree with the data already reported from Berkeley and Cornell.",
        "issn": "0031-899X",
        "publisher": "American Physical Society",
        "publication": "Physical Review",
        "publication_date": "1953-06-15",
        "series_number": "4",
        "volume": "90",
        "issue": "4",
        "pages": "1090-1091"
    }
]