The first measured high-precision data on the differential cross sections and polarization observable beam asymmetry Σ for the γp→π-Δ++ reaction from the LEPS collaboration are analyzed within a tree-level effective lagrangian approach. In addition to the t-channel π and ρ exchanges, the u-channel Δ exchange, the s-channel N exchange, and the interaction current that is required by the gauge invariance, the s-channel nucleon resonance exchanges are further taken into account to reproduce the data of LEPS. Numerical results show that, the data on Σ can not be well reproduced when no contributions from the s-channel resonance exchanges are introduced. Further analyses show that, by including the contribution from the resonance N(1860)5/2+, both the data on the differential cross sections and beam asymmetry Σ can be well reproduced.
ZHU Yiming
,
YANG Fuzhong
. Nucleon resonances in γp→π-Δ++ photoproduction[J]. Journal of University of Chinese Academy of Sciences, 2024
, 41(1)
: 35
-41
.
DOI: 10.7523/j.ucas.2021.0042
[1] Anisovich A V，Burkert V，Dugger M，et al.Proton-η' interactions at threshold[J].Physics Letters B，2018，785：626-630.DOI:10.1016/j.physletb.2018.06.034.
[2] Kim S H，Hosaka A，Kim H C.Effects of N(2000) 5/2+, N (2060) 5/2-, N (2120) 3/2-, and N (2190) 7/2- on K*Λ photoproduction[EB/OL].(2014-02-07)[2021-04-10].http://arxiv.org/abs/1402.1753.
[3] Moriya K，Schumacher R A，Adhikari K P，et al.Differential photoproduction cross sections of the Σ0(1385), Λ(1405), and Λ(1520)[J].Physical Review C，2013，88(4)：045201.DOI:10.1103/PhysRevC.88.045201.
[4] Tiator L，Gorchtein M，Kashevarov V L，et al.Eta and etaprime photoproduction on the nucleon with the isobar model EtaMAID2018[J].The European Physical Journal A，2018，54(12)：210.DOI:10.1140/epja/i2018-12643-x.
[5] Wang A C，Wang W L，Huang F，et al.Nucleon resonances in γp → K*+Λ[EB/OL]. 2017: arXiv:1704.04562. (2017-04-15)[2021-04-08]. http://arxiv.org/abs/1704.04562.
[6] Wang A C，Wang W L，Huang F.Effects of Δ(1905)5/2+ on K*Σ photoproduction[EB/OL].2018: arXiv:1810.07012.(2018-10-14)[2021-03-15]. http://arxiv.org/abs/1810.07012/.
[7] Wang A C，Huang F，Wang W L，et al.Photoproduction γp → K*+Λ in a Reggeized model[J].Physical Review C，2020，102：015203.DOI:10.1103/physrevc.102.015203.
[8] Wang A C，Wang W L，Huang F.Nucleon and Δ resonances in γp → K+Σ0(1385) photoproduction[EB/OL].(2020-02-11)[2021-03-10]. https://doi.org/10.48550/arXiv.2002.04213.
[9] Wang E，Xie J J，Liang W H，et al.Role of a triangle singularity in the γp → K+Λ(1405) reaction[EB/OL].2016.arXiv:1610.07117. (2016-10-23)[20210-03-20]. https://arxiv.org/abx/1610.07117.
[10] Wei N C，Huang F，Nakayama K，et al.Nucleon resonances in γp → ωp reaction[J].Physical Review D，2019，100(11)：114026.DOI: 10.1103/physrevd.100.114026.
[11] Wei N C，Wang A C，Huang F，et al.Analysis of the data on spin density matrix elements for γp → K*+Λ[J].Physical Review C，2020，101：014003.DOI: 10.1103/physrevc.101.014003.
[12] Wei N C，Zhang Y，Huang F，et al.Photoproduction γp→K+Λ(1520) in an effective Lagrangian approach[J].Physical Review D，2021，103(3)：034007. DOI: 10.1103/physRevD.103.034007.
[13] Zhang Y，Huang F.Effects of N(2000)5/2+ on γp → K+Λ(1405)[EB/OL].2021:arXiv:2102.10404.(2021-02-20)[2021-04-10]. https://arxiv.org/abs/2102.10404.
[14] Kohri H，Shiu S H，Chang W C，et al.Differential Cross Section and Photon-Beam Asymmetry for the γp→π-Δ++(1232) Reaction at Forward π- Angles for Eγ=1.5~2.95 GeV[J].Physical Review Letters，2018，120(20)：202004.DOI: 10.1103/PhysRevlett.120.202004.
[15] Nam S I，Yu B G.Charged pion photoproduction with the Δ(1232) baryon beyond the resonance region[J].Physical Review C，2011，84(2)：025203.DOI: 10.1103/physrevc.84.025203.
[16] Haberzettl H，Nakayama K，Krewald S.Gauge-invariant approach to meson photoproduction including the final-state interaction[J]. Physical Review C，2006，74(4)：045202. DOI: 10.1103/physrevc.74.045202.
[17] Haberzettl H.Gauge-invariant theory of pion photoproduction with dressed hadrons[J]. Physical Review C，1997，56(4)：2041-2058. DOI: 10.1103/physrevc.87.054004.
[18] Huang F，Haberzettl H，Nakayama K.Combined analysis of η' production reactions: γN→η'N, NN→NNη', and πN → η'N[J].Physical Review C，2013，87(5)：054004. DOI: 10.1103/physrevc.87.054004.
[19] Huang F，Döring M，Haberzettl H，et al.Pion photoproduction in a dynamical coupled-channels model[J].Physical Review C，2012，85(5)：054003. DOI: 10.1103/physrevc.85.054003.
[20] Behrends R E，Fronsdal C.Fermi decay of higher spin particles[J].Physical Review，1957，106(2)：345. DOI: 10.1103/physrev.106.345.
[21] Fronsdal C.On the theory of higher spin fields[J].Il Nuovo Cimento (1955-1965)，1958，9(2)：416-443.
[22] Zhu J J，Yan M L.Covariant amplitudes for mesons [EB/OL]. arXiv：9903349.(1999-03-15)[2020-10-12].https://arxiv.org/abs/hep-ph/9903349.
[23] Tanabashi M，Hagiwara K，Hikasa K，et al.Review of Particle Physics[J].Physical Review D，2018，98(3)：030001. DOI: 10.1103/physrevd.98.030001.
