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 d σ /d t , 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 GeV 2 . Moreover, differential cross sections d σ /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.
Related
- Meson photoproduction at Jefferson Lab: from two-meson final states to meson-baryon spin-density matrices
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- Multi-Differential DVCS Cross Section Measurement on the Proton in the Valence Region with CLAS12
BibTeX
@article{hu2026first,
title = {{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}},
author = {T Hu and Z Akbar and V Crede and J.M Laget and V Mathieu and M.J Amaryan and W.R Armstrong and H Atac and N.A Baltzell and L Barion and M Battaglieri and I Bedlinskiy and B Benkel and F Benmokhtar and A Bianconi and L Biondo and A Biselli and M Bondi and F Bossù and S Boiarinov and W.J Briscoe and S Bueltmann and D Bulumulla and V.D Burkert and R Capobianco and D.S Carman and J.C Carvajal and A Celentano and T Chetry and G Ciullo and G Clash and P.L Cole and M Contalbrigo and G Costantini and A d'Angelo and N Dashyan and R de Vita and M Defurne and A Deur and S Diehl and C Djalali and R Dupre and H Egiyan and A El Alaoui and L El Fassi and L Elouadrhiri and P Eugenio and S Fegan and A Filippi and G Gavalian and Y Ghandilyan and G.P Gilfoyle and F Girod and A.A Golubenko and G Gosta and R.W Gothe and K.A Griffioen and M Guidal and K Hafidi and H Hakobyan},
journal = {Physics Letters B},
year = {2026},
month = sep,
doi = {10.1016/j.physletb.2026.140845},
eprint = {2608.11467},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05733757v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - 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
AU - T Hu
AU - Z Akbar
AU - V Crede
AU - J.M Laget
AU - V Mathieu
AU - M.J Amaryan
AU - W.R Armstrong
AU - H Atac
AU - N.A Baltzell
AU - L Barion
AU - M Battaglieri
AU - I Bedlinskiy
AU - B Benkel
AU - F Benmokhtar
AU - A Bianconi
AU - L Biondo
AU - A Biselli
AU - M Bondi
AU - F Bossù
AU - S Boiarinov
AU - W.J Briscoe
AU - S Bueltmann
AU - D Bulumulla
AU - V.D Burkert
AU - R Capobianco
AU - D.S Carman
AU - J.C Carvajal
AU - A Celentano
AU - T Chetry
AU - G Ciullo
AU - G Clash
AU - P.L Cole
AU - M Contalbrigo
AU - G Costantini
AU - A d'Angelo
AU - N Dashyan
AU - R de Vita
AU - M Defurne
AU - A Deur
AU - S Diehl
AU - C Djalali
AU - R Dupre
AU - H Egiyan
AU - A El Alaoui
AU - L El Fassi
AU - L Elouadrhiri
AU - P Eugenio
AU - S Fegan
AU - A Filippi
AU - G Gavalian
AU - Y Ghandilyan
AU - G.P Gilfoyle
AU - F Girod
AU - A.A Golubenko
AU - G Gosta
AU - R.W Gothe
AU - K.A Griffioen
AU - M Guidal
AU - K Hafidi
AU - H Hakobyan
PY - 2026
DA - 2026/09/01
JO - Physics Letters B
DO - 10.1016/j.physletb.2026.140845
UR - https://hal.science/hal-05733757v1
AB - We report on the differential cross sections d σ /d t , 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 GeV 2 . Moreover, differential cross sections d σ /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.
SN - 0370-2693
SN - 1873-2445
ER -