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  • Letter
  • Open Access

Demonstration of collinear factorization breaking due to collinear-to-soft Glauber exchanges for a 2→3 exclusive process at leading twist

Saad Nabeebaccus1,2,*, Jakob Schönleber3,4,†, Lech Szymanowski5,‡, and Samuel Wallon1,§

  • *Contact author: saad.nabeebaccus@manchester.ac.uk
  • †Contact author: jschoenle@bnl.gov
  • ‡Contact author: Lech.Szymanowski@ncbj.gov.pl
  • §Contact author: Samuel.Wallon@ijclab.in2p3.fr
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Phys. Rev. D 111, L091502 – Published 9 May, 2025

DOI: https://doi.org/10.1103/PhysRevD.111.L091502

Abstract

We exhibit an exclusive process, namely the photoproduction of a π0γ pair with large invariant mass, which violates collinear factorization. We explicitly demonstrate that this is due to the fact that there exists diagrams with gluon exchange in t channel, contributing at the leading power, for which Glauber gluons are trapped. This is caused by the pinching of the contour integration of both the plus and minus light-cone components of the Glauber gluon momentum. We argue that this leads to the observed “end pointlike” divergence of the convolution integral at leading order and leading power when collinear factorization is naïvely assumed.

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References (21)

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Outline

Information

Phys. Rev. D 111, L091502– Published 9 May, 2025
  • Received 22 November 2023
  • Revised 4 October 2024
  • Accepted 11 April 2025
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