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DOE OSTI · 3678319

First measurement of polarized spin-density matrix elements and differential cross sections dσ/dt in ω photoproduction off the proton for 2.7 < Eγ < 5.2 GeV using CLAS at Jefferson Lab

Abstract

We report on the differential cross sections dσ/dt, the unpolarized spin-density matrix elements ρ 00 0 , ρ 1 − 1 0 , Re ρ 10 0 , and the first extraction of the polarized elements Im ρ 10 3 , Im ρ 1 − 1 3 for the reaction γp → pω using the CLAS spectrometer at Jefferson Laboratory. The ω mesons were detected in their dominant charged decay mode, ω → π + π − π 0 , and all t-dependent results are presented in a fine binning for incident photon energies between 2.73 and 5.16 GeV (corresponding to the center-of-mass energy range W ∈ [ 2.45, 3.25 ] GeV). All matrix elements are first measurements for − t > 0.6 GeV2. Moreover, differential cross sections dσ/d(cos Θ c . m . ω ) and the corresponding angle-dependent unpolarized spin-density matrix elements in the Adair frame are presented for the incident photon energy range 1.56–3.80 GeV (corresponding to W ∈ [ 1.95, 2.83 ] GeV). These new ω photoproduction data are consistent with earlier CLAS results but extend the energy range well beyond the nucleon resonance region into the Regge regime. The comparison with Regge-theory-based model predictions shows that the new data impose more stringent constraints on our understanding of ω photoproduction.

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BibTeXRIS

Hu, T., Akbar, Z., Crede, V. (ORCID:0000000246574945), Laget, J.M., Mathieu, V., Amaryan, M.J., Armstrong, W.R., Atac, H., Baltzell, N.A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W.J., Bueltmann, S., Bulumulla, D., Burkert, V.D., Capobianco, R., Carman, D.S., Carvajal, J.C., Celentano, A., Chetry, T., Ciullo, G., Clash, G., Cole, P.L., Contalbrigo, M., Costantini, G., D’Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G.P., Girod, F.X., Golubenko, A.A., Gosta, G., Gothe, R.W., Griffioen, K.A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T.B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D.G., Isupov, E.L., Jenkins, D., Jo, H.S., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F.J., Klimenko, V., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I.J.D., Marchand, D., Marsicano, L., Mascagna, V., McCracken, M.E., McKinnon, B., Meziani, Z.E., Migliorati, S., Milner, R.G., Mineeva, T., Mirazita, M., Mokeev, V., Munoz Camacho, C., Nadel-Turonski, P.. 2026-09-01. First measurement of polarized spin-density matrix elements and differential cross sections dσ/dt in ω photoproduction off the proton for 2.7 < Eγ < 5.2 GeV using CLAS at Jefferson Lab. https://doi.org/10.1016/j.physletb.2026.140845

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