Probing proton structure with c c ¯ correlations in ultraperipheral pA collisions
(2023) In Journal of High Energy Physics 2023(10).- Abstract
We study the exclusive diffractive cc¯ photoproduction in ultraperipheral pA collisions. The formalism makes use of off-diagonal generalizations of the unintegrated gluon distribution, the so-called generalized transverse momentum dependent distributions (GTMDs). We present two different formulations. The first one is based directly on gluon GTMD parametrizations in momentum space. Another option is the calculation of the GTMD as a Fourier transform of the dipole-nucleon scattering amplitude N(Y, r→ ⊥, b→ ⊥). The latter approach requires some extra regularization discussed in the paper. Different dipole amplitudes from the literature are used. Compared to previous calculations in the literature, we integrate over... (More)
We study the exclusive diffractive cc¯ photoproduction in ultraperipheral pA collisions. The formalism makes use of off-diagonal generalizations of the unintegrated gluon distribution, the so-called generalized transverse momentum dependent distributions (GTMDs). We present two different formulations. The first one is based directly on gluon GTMD parametrizations in momentum space. Another option is the calculation of the GTMD as a Fourier transform of the dipole-nucleon scattering amplitude N(Y, r→ ⊥, b→ ⊥). The latter approach requires some extra regularization discussed in the paper. Different dipole amplitudes from the literature are used. Compared to previous calculations in the literature, we integrate over the full phase space and therefore cross sections for realistic conditions are obtained. We present distributions in rapidity of c or c¯ , transverse momentum of the cc¯ pair, four-momentum transfer squared as well as the azimuthal correlation between a sum and a difference of the c and c¯ transverse momenta. The azimuthal correlations are partially due to the so-called elliptic gluon Wigner distribution. Different models lead to different modulations in the azimuthal angle. The modulations are generally smaller than 5%. They depend on the range of transverse momentum selected for the calculation.
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- author
- Linek, Barbara ; Łuszczak, Agnieszka ; Łuszczak, Marta ; Pasechnik, Roman LU ; Schäfer, Wolfgang and Szczurek, Antoni
- organization
- publishing date
- 2023-10
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Parton Distributions, Properties of Hadrons
- in
- Journal of High Energy Physics
- volume
- 2023
- issue
- 10
- article number
- 179
- publisher
- Springer
- external identifiers
-
- scopus:85175642010
- ISSN
- 1029-8479
- DOI
- 10.1007/JHEP10(2023)179
- language
- English
- LU publication?
- yes
- id
- 5dd3ec5a-6b50-49d8-9b2b-379319bf909a
- date added to LUP
- 2023-11-24 08:53:15
- date last changed
- 2025-04-04 14:35:05
@article{5dd3ec5a-6b50-49d8-9b2b-379319bf909a,
abstract = {{<p>We study the exclusive diffractive cc¯ photoproduction in ultraperipheral pA collisions. The formalism makes use of off-diagonal generalizations of the unintegrated gluon distribution, the so-called generalized transverse momentum dependent distributions (GTMDs). We present two different formulations. The first one is based directly on gluon GTMD parametrizations in momentum space. Another option is the calculation of the GTMD as a Fourier transform of the dipole-nucleon scattering amplitude N(Y, r→ <sub>⊥</sub>, b→ <sub>⊥</sub>). The latter approach requires some extra regularization discussed in the paper. Different dipole amplitudes from the literature are used. Compared to previous calculations in the literature, we integrate over the full phase space and therefore cross sections for realistic conditions are obtained. We present distributions in rapidity of c or c¯ , transverse momentum of the cc¯ pair, four-momentum transfer squared as well as the azimuthal correlation between a sum and a difference of the c and c¯ transverse momenta. The azimuthal correlations are partially due to the so-called elliptic gluon Wigner distribution. Different models lead to different modulations in the azimuthal angle. The modulations are generally smaller than 5%. They depend on the range of transverse momentum selected for the calculation.</p>}},
author = {{Linek, Barbara and Łuszczak, Agnieszka and Łuszczak, Marta and Pasechnik, Roman and Schäfer, Wolfgang and Szczurek, Antoni}},
issn = {{1029-8479}},
keywords = {{Parton Distributions; Properties of Hadrons}},
language = {{eng}},
number = {{10}},
publisher = {{Springer}},
series = {{Journal of High Energy Physics}},
title = {{Probing proton structure with c c ¯ correlations in ultraperipheral pA collisions}},
url = {{http://dx.doi.org/10.1007/JHEP10(2023)179}},
doi = {{10.1007/JHEP10(2023)179}},
volume = {{2023}},
year = {{2023}},
}