Hard exclusive meson production in muon scattering at COMPASS
We report on measurements of hard exclusive muoproduction of ρ0, ω and π0 mesons on the proton at COMPASS using 160 GeV/c polarized μ+ and μ− beams scattering off a liquid hydrogen target. The extracted Spin Density Matrix Elements for vector mesons indicate a violation of s-channel helicity conserv...
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| Format: | Article |
| Language: | English |
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EDP Sciences
2022-01-01
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| Series: | EPJ Web of Conferences |
| Online Access: | https://www.epj-conferences.org/articles/epjconf/pdf/2022/14/epjconf_qcd@work2022_00006.pdf |
| _version_ | 1811218888577253376 |
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| author | Sandacz Andrzej |
| author_facet | Sandacz Andrzej |
| author_sort | Sandacz Andrzej |
| collection | DOAJ |
| description | We report on measurements of hard exclusive muoproduction of ρ0, ω and π0 mesons on the proton at COMPASS using 160 GeV/c polarized μ+ and μ− beams scattering off a liquid hydrogen target. The extracted Spin Density Matrix Elements for vector mesons indicate a violation of s-channel helicity conservation for transitions of transversely polarized virtual photons to longitudinally polarized vector mesons, γT → VL, where V denotes ρ0 or ω meson. Additionally, for ρ0 production we observe a dominant contribution of natural-parity-exchange transitions and a small contribution of unnaturalparity-exchange transitions. On the contrary, the contribution of unnaturalparity-exchange for ω production is significant and it decreases with increasing W, being still non-negligible at the largest W values accessible at COMPASS. Further, we present also the absolute value of the differential cross section for exclusive π0 production and its dependence on squared four-momentum transfer t and azimuthal angle ø between the scattering plane and π0 production plane. The results provide an important input for modeling Generalized Parton Distribution (GPDs), and in particular to constrain chiral-odd (transversity) GPDs. |
| first_indexed | 2024-04-12T07:17:01Z |
| format | Article |
| id | doaj.art-4e9fe3619ce544eb8247170f1d56f7c7 |
| institution | Directory Open Access Journal |
| issn | 2100-014X |
| language | English |
| last_indexed | 2024-04-12T07:17:01Z |
| publishDate | 2022-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | EPJ Web of Conferences |
| spelling | doaj.art-4e9fe3619ce544eb8247170f1d56f7c72022-12-22T03:42:25ZengEDP SciencesEPJ Web of Conferences2100-014X2022-01-012700000610.1051/epjconf/202227000006epjconf_qcd@work2022_00006Hard exclusive meson production in muon scattering at COMPASSSandacz Andrzej0National Institute for Nuclear Research, Division of High Energy PhysicsWe report on measurements of hard exclusive muoproduction of ρ0, ω and π0 mesons on the proton at COMPASS using 160 GeV/c polarized μ+ and μ− beams scattering off a liquid hydrogen target. The extracted Spin Density Matrix Elements for vector mesons indicate a violation of s-channel helicity conservation for transitions of transversely polarized virtual photons to longitudinally polarized vector mesons, γT → VL, where V denotes ρ0 or ω meson. Additionally, for ρ0 production we observe a dominant contribution of natural-parity-exchange transitions and a small contribution of unnaturalparity-exchange transitions. On the contrary, the contribution of unnaturalparity-exchange for ω production is significant and it decreases with increasing W, being still non-negligible at the largest W values accessible at COMPASS. Further, we present also the absolute value of the differential cross section for exclusive π0 production and its dependence on squared four-momentum transfer t and azimuthal angle ø between the scattering plane and π0 production plane. The results provide an important input for modeling Generalized Parton Distribution (GPDs), and in particular to constrain chiral-odd (transversity) GPDs.https://www.epj-conferences.org/articles/epjconf/pdf/2022/14/epjconf_qcd@work2022_00006.pdf |
| spellingShingle | Sandacz Andrzej Hard exclusive meson production in muon scattering at COMPASS EPJ Web of Conferences |
| title | Hard exclusive meson production in muon scattering at COMPASS |
| title_full | Hard exclusive meson production in muon scattering at COMPASS |
| title_fullStr | Hard exclusive meson production in muon scattering at COMPASS |
| title_full_unstemmed | Hard exclusive meson production in muon scattering at COMPASS |
| title_short | Hard exclusive meson production in muon scattering at COMPASS |
| title_sort | hard exclusive meson production in muon scattering at compass |
| url | https://www.epj-conferences.org/articles/epjconf/pdf/2022/14/epjconf_qcd@work2022_00006.pdf |
| work_keys_str_mv | AT sandaczandrzej hardexclusivemesonproductioninmuonscatteringatcompass |