Studying <math display="inline"><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>-</mo></msup></math> photoproduction beyond Pomeron exchange

Bibrzycki, Łukasz; Hammoud, Nadine; Mathieu, Vincent; Perry, Robert J.; Akridge, Alex; Fernández-Ramírez, César; Montaña, Gloria; Pilloni, Alessandro; Rodas, Arkaitz; Shastry, Vanamali

doi:10.1103/PhysRevD.111.014002

Studying $π^{+} π^{-}$ photoproduction beyond Pomeron exchange

Joint Physics Analysis Center

Collaboration

•

Łukasz Bibrzycki
(
- AGH-UST, Cracow
)

Jun 12, 2024

30 pages

Published in:

Phys.Rev.D 111 (2025) 1, 014002

Published: Jan 1, 2025

e-Print:

2406.08016 [hep-ph]

DOI:

10.1103/PhysRevD.111.014002 (publication)

Report number:

JLAB-THY-24-4078

View in:

ADS Abstract Service

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Abstract: (APS)

Forward photoproduction of

π^{+} π^{-}

pairs with invariant mass of the order of

m_{ρ} \sim 770 MeV

is traditionally attributed to Pomeron exchange. Based on a detailed analysis of the CEBAF Large Acceptance Spectrometer photoproduction data collected at photon energies below 4 GeV, it is shown from a study of the angular moments that the dynamics of two-pion photoproduction for

| t | ≳ 0.5 {GeV}^{2}

cannot be explained by Pomeron exchange alone. This motivates the development of a new theoretical model of two-pion photoproduction which incorporates both two-pion and pion-nucleon resonant contributions. After fitting free parameters, the model provides an excellent description of the low moments of the angular distribution measured at CLAS and enables an assessment of the relative contributions of particular production mechanisms and an interpretation of the various features of the data in terms of these mechanisms.

Note:

30 pages, 21 figures

References(49)

Figures(23)

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