Breakdown of collinear factorization in the exclusive photoproduction of a π 0 γ pair with large invariant mass
Year: 2025
Type: article
Abstract: We exhibit an exclusive process, namely the photoproduction of a π 0 γ 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 are . This is caused by the pinching of the contour integration of 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.
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Funders: U.S. Department of Energy, Strong, Royal Society, European Commission, Agence Nationale de la Recherche, Labex, Narodowe Centrum Nauki, Centre National de la Recherche Scientifique, Université Paris-Saclay, Horizon 2020 Framework Programme, Science and Technology Facilities Council, Institut National de Physique Nucléaire et de Physique des Particules, Laboratory Directed Research and Development
Awards: G1255754732, G1610782679, G241279073, Idex Paris-Saclay, G3111662533, The strong interaction at the frontier of knowledge: fundamental research and applications, G383969532, G4201897825, G434337789, Boosting the precision of quarkonium-production studies, G4750045048, G4866930200, G4920325777, G5424167748, G5765906131, G6350981294, G6859546288, G6861531787, Manchester Particle Theory Consolidated Grant 2022 : Particle Physics in Colliders and the Cosmos, G6877514435, G7240651115, G7451223319, G7497762939, G7603157382, G7628294500, G7973282807, G8577729007
OpenAlex ID: W4407957799