Backward pion photoproduction

Journal Article · Wed Apr 01 04:00:00 EDT 2009 · European Physical Journal A

DOI:https://doi.org/10.1140/epja/i2008-10743-x· OSTI ID:979631

Sibirtsev, A; Haidenbauer, J; Huang, F; Krewald, S; Meissner, U -G

We present a systematic analysis of backward pion photoproduction for the reactions $$ \gamma$$ p $$ \rightarrow$$ $$ \pi^{0}_{}$$ p and $$ \gamma$$ p $$ \rightarrow$$ $$ \pi^{+}_{}$$ n . Regge phenomenology is applied at invariant collision energies above 3GeV in order to fix the reaction amplitude. A comparision with older data on $$ \pi^{0}_{}$$ - and $$ \pi^{+}_{}$$ -photoproduction at $$ \vartheta$$ = 180° indicates that the high-energy limit as given by the Regge calculation could be reached possibly at energies of around $$ \sqrt{{s}}$$ ≃ 3 GeV. In the energy region of $$ \sqrt{{s}}$$ $$ \le$$2.5 GeV, covered by the new measurements of $$ \gamma$$ p $$ \rightarrow$$ $$ \pi^{0}_{}$$ p differential cross-sections at large angles at ELSA, JLab, and LEPS, we see no clear signal for a convergence towards the Regge results. The baryon trajectories obtained in our analysis are in good agreement with those given by the spectrum of excited baryons.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 979631
• Report Number(s): JLAB-THY-09-959; DOE/OR/23177-0676
• Journal Information: European Physical Journal A, Journal Name: European Physical Journal A Journal Issue: 1 Vol. 40
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
CONVERGENCE
CROSS SECTIONS
PHOTOPRODUCTION
PIONS
TRAJECTORIES