Measurement of the helicity asymmetry E for the reaction $$ \gamma p\rightarrow \pi ^0 p$$

Gottschall, M.; Afzal, F.; Anisovich, A. V.; Bayadilov, D.; Beck, R.; Bichow, M.; Brinkmann, K.-Th.; Credé, V.; Dieterle, M.; Dietz, F.; Dutz, H.; Eberhardt, H.; Elsner, D.; Ewald, R.; Fornet-Ponse, K.; Friedrich, S.; Frommberger, F.; Gridnev, A.; Grüner, M.; Gutz, E.; Hammann, Ch.; Hannappel, J.; Hartmann, J.; Hillert, W.; Hoffmeister, P.; Honisch, Christiane; Jude, Thomas; Kammer, S.; Kalinowsky, H.; Keshelashvili, I.; Klassen, P.; Klein, F.; Klempt, E.; Koop, K.; Krusche, B.; Kube, M.; Lang, Μ.; Lopatin, I.; Mahlberg, P.; Makónyi, K.; Metag, V.; Meyer, W.; Müller, J.; Müllers, J.; Nanova, M.; Nikonov, V. A.; Novotny, R.; Piontek, D.; Reicherz, G.; Rostomyan, T.; Sarantsev, A.; Schmidt, Ch.; Schmieden, H.; Seifen, T.; Sokhoyan, V.; Spieker, K.; Thiel, A.; Thoma, U.; Urban, M.; Pee, H. van; Walther, Dirk; Wendel, Ch.; Werthmüller, D.; Wiedner, U.; Wilson, A.; Winnebeck, A.; Witthauer, L.; Wunderlich, Y.

doi:10.1140/epja/s10050-020-00334-2

Cited by 8 publications

(8 citation statements)

References 85 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[122], as well as the CBELSA/TAPS data on E in γ p → π 0 p from Ref. [126] and on in γ p → ηp from Ref. [84] and the BGOOD data on dσ/d and P at forward angles for K + photoproduction [83].…”

Section: Appendix B: Further Fit Resultsmentioning

confidence: 98%

Light baryon resonances from a coupled-channel study including $$\mathbf {K\Sigma }$$ photoproduction

et al. 2022

View full text Add to dashboard Cite

The Jülich-Bonn dynamical coupled-channel approach is extended to include $$K\Sigma $$ K Σ photoproduction off the proton. Differential cross section and (double) polarization data for $$K^+\Sigma ^0$$ K + Σ 0 and $$K^0\Sigma ^+$$ K 0 Σ + are analysed simultaneously with the pion- and photon-induced production of $$\pi N$$ π N , $$\eta N$$ η N , $$K\Lambda $$ K Λ , and $$K\Sigma $$ K Σ final states, totaling almost 72,000 data points for center-of-mass energies $$W<2.4$$ W < 2.4 GeV. Based on the fit results the spectrum of $$N^*$$ N ∗ and $$\Delta $$ Δ resonances is extracted in terms of pole positions and residues. We discuss the impact of the $$\gamma p\rightarrow K\Sigma $$ γ p → K Σ channels in detail and investigate the influence of recent polarization data for $$\eta p$$ η p photoproduction.

show abstract

Section: Appendix B: Further Fit Resultsmentioning

confidence: 98%

Light baryon resonances from a coupled-channel study including $$\mathbf {K\Sigma }$$ photoproduction

et al. 2022

View full text Add to dashboard Cite

show abstract

“…One of the well-measured double polarization observable is the observable E, which is closely related to the helicity asymmetry σ 3/2 − σ 1/2 , see for example [190,134]. This asymmetry has already been published by the GDH experiment at MAMI in 2002 and 2004 [191,124,192], but a normalization, which leads to the observable E had been missing.…”

Section: Pion Photoproductionmentioning

confidence: 99%

“…This asymmetry has already been published by the GDH experiment at MAMI in 2002 and 2004 [191,124,192], but a normalization, which leads to the observable E had been missing. This was first done by the CBELSA/TAPS collaboration for the pπ 0 final state [190,134]. In the last years, the data base for this observable has been extend for all other final states by measurements from the CLAS collaboration for nπ + [188] and pπ − [193] Figure 24: The beam asymmetry Σ from the BGOegg experiment (closed circles) [144] and from CLAS (open squares) [181] for the reaction γp → pπ 0 .…”

Section: Pion Photoproductionmentioning

confidence: 99%

See 1 more Smart Citation

Light Baryon Spectroscopy

Thiel,

Afzal,

Wunderlich

2022

Preprint

View full text Add to dashboard Cite

This review treats the advances in Light Baryon Spectroscopy of the last two decades, which were mainly obtained by measuring meson-production reactions at photon facilities all over the world. We provide a consistent compendium of experimental results, as well as a review of the theoretical methods of amplitude analysis used to analyze the data. The most significant datasets are presented in detail and are listed in combination with a full set of the relevant references. In addition, a brief summary of spin-formalisms, which are ubiquitous in Light Baryon Spectroscopy, as well as a review on complete experiments, are provided. The synthesis of the reviewed knowledge is presented in a full interpretation of the new results on the Light Baryon Spectrum.

show abstract

“…Large contributions came from the CBELSA/TAPS experiment, which is located at the ELSA accelerator in Bonn, Germany. Here, double polarization observables have been measured for reactions comprising neutral mesons utilizing a circularly or linearly polarized photon beam in combination with a longitudinally or transversely polarized frozen-spin target, see for example [7,8]. At lower energies, several datasets have been published by the A2 experiment, located at the MAMI accelerator in Mainz, Germany.…”

Section: Experimental Facilitiesmentioning

confidence: 99%

Light Baryon Spectroscopy

Thiel

2023

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The precise understanding of the interaction inside the nucleons is still an open question in hadron spectroscopy. To tackle this issue, nucleons are excited by photons and their excitation spectra are determined. This effort is addressed by several different experiments worldwide, where different polarization observables are extracted for various reactions. This proceeding will give a short overview about the current status in Light Baryon Spectroscopy.

show abstract

Measurement of the helicity asymmetry E for the reaction $$ \gamma p\rightarrow \pi ^0 p$$

Abstract: A measurement of the double-polarization observable E for the reaction $$\gamma p\rightarrow \pi ^0 p$$ γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C$$_4$$ … Show more

Cited by 8 publications

References 85 publications

Light baryon resonances from a coupled-channel study including $$\mathbf {K\Sigma }$$ photoproduction

Light baryon resonances from a coupled-channel study including $$\mathbf {K\Sigma }$$ photoproduction

Light Baryon Spectroscopy

Light Baryon Spectroscopy

Contact Info

Product

Resources

About