2017/03/13 by V. R. Debastiani, Shuntaro Sakai, S. Sakai +1
Mathematics · Physics and Astronomy · #Combinatorics #Geometry #Mathematics #Nuclear physics research studies #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Singularity #hep-ph
paper · pdf · doi:10.1103/physrevc.96.025201
published as Phys. Rev. C 96, 025201 (2017) · 8 pages, 6 figures, minor correction in Fig. 5 and acknowledgments added
arxiv created 2017/03/13 · openalex created_date 2017/03/16 · openalex publication_date 2017/08/02 · arxiv updated 2017/08/08 · openalex updated_date 2026/08/05
We have studied the \ensuremathγp\ensuremath→p\ensuremathπ0\ensuremathη reaction paying attention to the two main mechanisms at low energies, the \ensuremathγp\ensuremath→\mathrm\ensuremathΔ(1700)\ensuremath→\ensuremathη\mathrm\ensuremathΔ(1232) and the \ensuremathγp\ensuremath→\mathrm\ensuremathΔ(1700)\ensuremath→\ensuremathπN(1535). Both are driven by the photoexcitation of the \mathrm\ensuremathΔ(1700) and the second one involves a mechanism that leads to a triangle singularity. We are able to evaluate quantitatively the cross section for this process and show that it agrees with the experimental determination. Yet there are some differences with the standard partial wave analysis which does not include explicitly the triangle singularity. The exercise also shows the convenience of exploring possible triangle singularities in other reactions and how a standard partial wave analysis can be extended to accommodate them.