Abstract
We compute the exclusive photoproduction of a γπ± pair using the collinear factorisation framework, in the kinematic regime where the pair has a large invariant mass and the meson has a sufficiently large transverse momentum to not resonate with the outgoing nucleon. This exclusive channel presents a new avenue for the investigation of GPDs. It is particularly interesting as the high centre of mass energies available at future experiments will allow the study of GPDs at small skewness ξ. We compute the scattering amplitude of the process, at leading twist and leading order in αs, which is used to estimate its cross-section and linear polarisation asymmetries with respect to the incoming photon, for JLab 12-GeV, COMPASS, future EIC and LHC (in ultra-peripheral collisions) kinematics. We find that the order of magnitude of estimates are sufficiently large for a dedicated experimental analysis to be performed, especially at JLab. We also compare the results from an asymptotic distribution amplitude (DA) to those using a recently proposed holographic DA.
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References
D.Y. Ivanov, B. Pire, L. Szymanowski and O.V. Teryaev, Probing chiral odd GPD’s in diffractive electroproduction of two vector mesons, Phys. Lett. B 550 (2002) 65 [hep-ph/0209300] [INSPIRE].
R. Enberg, B. Pire and L. Szymanowski, Transversity GPD in photo- and electroproduction of two vector mesons, Eur. Phys. J. C 47 (2006) 87 [hep-ph/0601138] [INSPIRE].
M. El Beiyad et al., Photoproduction of a πρT pair with a large invariant mass and transversity generalized parton distribution, Phys. Lett. B 688 (2010) 154 [arXiv:1001.4491] [INSPIRE].
A. Pedrak, B. Pire, L. Szymanowski and J. Wagner, Hard photoproduction of a diphoton with a large invariant mass, Phys. Rev. D 96 (2017) 074008 [Erratum ibid. 100 (2019) 039901] [arXiv:1708.01043] [INSPIRE].
B. Pire, L. Szymanowski and S. Wallon, Diffractive deeply virtual Compton scattering, Phys. Rev. D 101 (2020) 074005 [Erratum ibid. 103 (2021) 059901] [arXiv:1912.10353] [INSPIRE].
A. Pedrak, B. Pire, L. Szymanowski and J. Wagner, Electroproduction of a large invariant mass photon pair, Phys. Rev. D 101 (2020) 114027 [arXiv:2003.03263] [INSPIRE].
W. Cosyn and B. Pire, Diffractive rho plus lepton pair production at an electron-ion collider, Phys. Rev. D 103 (2021) 114002 [arXiv:2103.01411] [INSPIRE].
K. Goeke, M.V. Polyakov and M. Vanderhaeghen, Hard exclusive reactions and the structure of hadrons, Prog. Part. Nucl. Phys. 47 (2001) 401 [hep-ph/0106012] [INSPIRE].
M. Diehl, Generalized parton distributions, Phys. Rept. 388 (2003) 41 [hep-ph/0307382] [INSPIRE].
A.V. Belitsky and A.V. Radyushkin, Unraveling hadron structure with generalized parton distributions, Phys. Rept. 418 (2005) 1 [hep-ph/0504030] [INSPIRE].
S. Boffi and B. Pasquini, Generalized parton distributions and the structure of the nucleon, Riv. Nuovo Cim. 30 (2007) 387 [arXiv:0711.2625] [INSPIRE].
M. Diehl, Generalized parton distributions, Phys. Rept. 388 (2003) 41 [hep-ph/0307382].
M. Guidal, Generalized Parton Distributions and deep virtual Compton scattering, Prog. Part. Nucl. Phys. 61 (2008) 89 [INSPIRE].
CLAS collaboration, First Measurement of Timelike Compton Scattering, Phys. Rev. Lett. 127 (2021) 262501 [arXiv:2108.11746] [INSPIRE].
G. Duplančić et al., Probing axial quark generalized parton distributions through exclusive photoproduction of a γπ± pair with a large invariant mass, JHEP 11 (2018) 179 [arXiv:1809.08104] [INSPIRE].
J.-W. Qiu and Z. Yu, Exclusive production of a pair of high transverse momentum photons in pion-nucleon collisions for extracting generalized parton distributions, JHEP 08 (2022) 103 [arXiv:2205.07846] [INSPIRE].
J.-W. Qiu and Z. Yu, Single diffractive hard exclusive processes for the study of generalized parton distributions, Phys. Rev. D 107 (2023) 014007 [arXiv:2210.07995] [INSPIRE].
O. Grocholski et al., Collinear factorization of diphoton photoproduction at next to leading order, Phys. Rev. D 104 (2021) 114006 [arXiv:2110.00048] [INSPIRE].
O. Grocholski et al., Phenomenology of diphoton photoproduction at next-to-leading order, Phys. Rev. D 105 (2022) 094025 [arXiv:2204.00396] [INSPIRE].
R. Boussarie, B. Pire, L. Szymanowski and S. Wallon, Exclusive photoproduction of a γρ pair with a large invariant mass, JHEP 02 (2017) 054 [Erratum ibid. 10 (2018) 029] [arXiv:1609.03830] [INSPIRE].
L. Mankiewicz, G. Piller and T. Weigl, Hard leptoproduction of charged vector mesons, Phys. Rev. D 59 (1999) 017501 [hep-ph/9712508] [INSPIRE].
A.V. Radyushkin, Double distributions and evolution equations, Phys. Rev. D 59 (1999) 014030 [hep-ph/9805342] [INSPIRE].
M. Glück, E. Reya and A. Vogt, Dynamical parton distributions revisited, Eur. Phys. J. C 5 (1998) 461 [hep-ph/9806404] [INSPIRE].
M. Glück, E. Reya, M. Stratmann and W. Vogelsang, Models for the polarized parton distributions of the nucleon, Phys. Rev. D 63 (2001) 094005 [hep-ph/0011215] [INSPIRE].
P. Ball, Theoretical update of pseudoscalar meson distribution amplitudes of higher twist: the Nonsinglet case, JHEP 01 (1999) 010 [hep-ph/9812375] [INSPIRE].
S.V. Mikhailov and A.V. Radyushkin, Nonlocal Condensates and QCD Sum Rules for Pion Wave Function, JETP Lett. 43 (1986) 712 [INSPIRE].
S.J. Brodsky and G.F. de Teramond, Hadronic spectra and light-front wavefunctions in holographic QCD, Phys. Rev. Lett. 96 (2006) 201601 [hep-ph/0602252] [INSPIRE].
C. Shi et al., Kaon and pion parton distribution amplitudes to twist-three, Phys. Rev. D 92 (2015) 014035 [arXiv:1504.00689] [INSPIRE].
X. Gao et al., Pion distribution amplitude at the physical point using the leading-twist expansion of the quasi-distribution-amplitude matrix element, Phys. Rev. D 106 (2022) 074505 [arXiv:2206.04084] [INSPIRE].
R. Abdul Khalek et al., Science Requirements and Detector Concepts for the Electron-Ion Collider: EIC Yellow Report, Nucl. Phys. A 1026 (2022) 122447 [arXiv:2103.05419] [INSPIRE].
Z. Citron et al., Report from Working Group 5: Future physics opportunities for high-density QCD at the LHC with heavy-ion and proton beams, CERN Yellow Rep. Monogr. 7 (2019) 1159 [arXiv:1812.06772] [INSPIRE].
G. Duplančić et al., Accessing GPDs through the exclusive photoproduction of a γ-meson pair, in the proceedings of 29th International Workshop on Deep-Inelastic Scattering and Related Subjects, Santiago de Compostela Spain, May 2–6 2022 [https://doi.org/10.5281/zenodo.7078119] [arXiv:2209.05380] [INSPIRE].
C. Alexandrou et al., Nucleon Spin and Momentum Decomposition Using Lattice QCD Simulations, Phys. Rev. Lett. 119 (2017) 142002 [arXiv:1706.02973] [INSPIRE].
C. Alexandrou et al., Complete flavor decomposition of the spin and momentum fraction of the proton using lattice QCD simulations at physical pion mass, Phys. Rev. D 101 (2020) 094513 [arXiv:2003.08486] [INSPIRE].
CLAS collaboration, Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transversity GPDs, Phys. Rev. Lett. 109 (2012) 112001 [arXiv:1206.6355] [INSPIRE].
Jefferson Lab Hall A collaboration, Rosenbluth separation of the π0 electroproduction cross section, Phys. Rev. Lett. 117 (2016) 262001 [arXiv:1608.01003] [INSPIRE].
P. Kroll, Hard exclusive pion leptoproduction, Few Body Syst. 57 (2016) 1041 [arXiv:1602.03803] [INSPIRE].
S.V. Goloskokov and P. Kroll, An Attempt to understand exclusive pi+ electroproduction, Eur. Phys. J. C 65 (2010) 137 [arXiv:0906.0460] [INSPIRE].
S.V. Goloskokov and P. Kroll, Transversity in hard exclusive electroproduction of pseudoscalar mesons, Eur. Phys. J. A 47 (2011) 112 [arXiv:1106.4897] [INSPIRE].
B. Nizic, Beyond leading order perturbative QCD corrections to γγ → M+M−(M = π, K), Phys. Rev. D 35 (1987) 80 [INSPIRE].
G. Duplančic and B. Nizic, NLO perturbative QCD predictions for γγ → M+M−(M = π, K), Phys. Rev. Lett. 97 (2006) 142003 [hep-ph/0607069] [INSPIRE].
P. Kessler, The Weizsäcker-Williams Method and Similar Approximation Methods in Quantum Electrodynamics, Acta Phys. Austriaca 41 (1975) 141 [INSPIRE].
S. Frixione, M.L. Mangano, P. Nason and G. Ridolfi, Improving the Weizsäcker-Williams approximation in electron-proton collisions, Phys. Lett. B 319 (1993) 339 [hep-ph/9310350] [INSPIRE].
S. Klein and J. Nystrand, Exclusive vector meson production in relativistic heavy ion collisions, Phys. Rev. C 60 (1999) 014903 [hep-ph/9902259] [INSPIRE].
G. Baur et al., Coherent gamma gamma and gamma-A interactions in very peripheral collisions at relativistic ion colliders, Phys. Rept. 364 (2002) 359 [hep-ph/0112211] [INSPIRE].
A.J. Baltz, The Physics of Ultraperipheral Collisions at the LHC, Phys. Rept. 458 (2008) 1 [arXiv:0706.3356] [INSPIRE].
S.R. Klein et al., STARlight: A Monte Carlo simulation program for ultra-peripheral collisions of relativistic ions, Comput. Phys. Commun. 212 (2017) 258 [arXiv:1607.03838] [INSPIRE].
R.D. Woods and D.S. Saxon, Diffuse Surface Optical Model for Nucleon-Nuclei Scattering, Phys. Rev. 95 (1954) 577 [INSPIRE].
Particle Data Group collaboration, Review of Particle Physics, Chin. Phys. C 38 (2014) 090001 [INSPIRE].
R. Kleiss and W.J. Stirling, Spinor Techniques for Calculating pp → W±/Z0 + Jets, Nucl. Phys. B 262 (1985) 235 [INSPIRE].
E. Leader, Spin in Particle Physics, Cambridge University Press (2001) [https://doi.org/10.1017/cbo9780511524455].
C. Bourrely, J. Soffer and E. Leader, Polarization Phenomena in Hadronic Reactions, Phys. Rept. 59 (1980) 95 [INSPIRE].
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Duplančić, G., Nabeebaccus, S., Passek-Kumerički, K. et al. Accessing chiral-even quark generalised parton distributions in the exclusive photoproduction of a γπ± pair with large invariant mass in both fixed-target and collider experiments. J. High Energ. Phys. 2023, 241 (2023). https://doi.org/10.1007/JHEP03(2023)241
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DOI: https://doi.org/10.1007/JHEP03(2023)241