Publication Date:
2020
abstract:
We report a measurement of the spin polarization of the recoiling neutron in deuterium photodisintegration, utilizing a new large acceptance polarimeter within the Crystal Ball at MAMI. The measured photon energy range of 300-700 MeV provides the first measurement of recoil neutron polarization at photon energies where the quark substructure of the deuteron plays a role, thereby providing important new constraints on photodisintegration mechanisms. A very high neutron polarization in a narrow structure centered around Eγ∼570 MeV is observed, which is inconsistent with current theoretical predictions employing nucleon resonance degrees of freedom. A Legendre polynomial decomposition suggests this behavior could be related to the excitation of the d∗(2380) hexaquark.
Iris type:
1.1 Articolo in rivista
List of contributors:
Bashkanov, M.; Watts, D. P.; Kay, S. J. D.; Abt, S.; Achenbach, P.; Adlarson, P.; Afzal, F.; Ahmed, Z.; Akondi, C. S.; Annand, J. R. M.; Arends, H. J.; Beck, R.; Biroth, M.; Borisov, N.; Braghieri, A.; Briscoe, W. J.; Cividini, F.; Collicott, C.; Costanza, S.; Denig, A.; Downie, E. J.; Drexler, P.; Fegan, S.; Fix, A.; Gardner, S.; Ghosal, D.; Glazier, D. I.; Gorodnov, I.; Gradl, W.; Gunther, M.; Gurevich, D.; Heijkenskjold, L.; Hornidge, D.; Huber, G. M.; Kaser, A.; Kashevarov, V. L.; Korolija, M.; Krusche, B.; Lazarev, A.; Livingston, K.; Lutterer, S.; Macgregor, I. J. D.; Manley, D. M.; Martel, P. P.; Miskimen, R.; Mornacchi, E.; Mullen, C.; Neganov, A.; Neiser, A.; Ostrick, M.; Otte, P. B.; Paudyal, D.; Pedroni, P.; Powell, A.; Prakhov, S. N.; Ron, G.; Sarty, A.; Sfienti, C.; Sokhoyan, V.; Spieker, K.; Steffen, O.; Strakovsky, I. I.; Strub, T.; Supek, I.; Thiel, A.; Thiel, M.; Thomas, A.; Usov, Y. A.; Wagner, S.; Walford, N. K.; Werthmuller, D.; Wettig, J.; Wolfes, M.; Zachariou, N.; Zana, L. A.
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