Pith. sign in

REVIEW 3 major objections 6 minor 230 references

Reaching 10^7 GeV: heavy-ion photon collisions set an energy record

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-01 15:09 UTC pith:BYMQJPQR

load-bearing objection A solid, honest review of UPC physics that deserves peer review, but it has real formula errors and copyediting problems that must be fixed before it can be used as an archival reference. the 3 major comments →

arxiv 2607.18535 v1 pith:BYMQJPQR submitted 2026-07-20 hep-ex hep-phnucl-exnucl-th

Ultra-peripheral Collisions

classification hep-ex hep-phnucl-exnucl-th
keywords ultra-peripheral collisionsphotonuclear interactionstwo-photon interactionsgluon saturationnuclear shadowingcoherent photoproductionlight-by-light scatteringquantum interference
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

Ultra-peripheral collisions (UPCs) — events in which two heavy ions pass close enough to interact electromagnetically but not hadronically — are claimed by this review to be the energy frontier for photon physics. The photons produced in these collisions reach about 10^7 GeV in the target frame and drive photon–nucleon collisions at center-of-mass energies an order of magnitude higher than any previous accelerator. On that basis, the review argues that UPC data have become a multi-purpose tool: they map the gluon structure of protons and nuclei down to Bjorken-x around 10^-6, they provide the strongest laboratory limits on tau anomalous moments and on axion-like particles in an intermediate mass window, and they expose quantum interference between two photon sources that never overlapped. If the review is correct, the field has entered a precision era in which nuclear shadowing, gluon saturation, and hadronic radii are being measured with photonuclear and two-photon reactions at hadron colliders.

Core claim

The central assertion is that UPCs now supply the most energetic photons available and that this capability has transformed several areas of physics. The review documents coherent J/psi photoproduction data spanning three orders of magnitude in x for both protons (down to ~10^-6) and nuclei (down to ~10^-5), measurements of nuclear shadowing and of event-by-event gluon-field fluctuations, two-photon production of tau pairs giving new constraints on tau electromagnetic moments, observation of light-by-light scattering and searches for axion-like particles, and the use of two-source interference to measure hadronic radii. The review's narrative is that these results, taken together, establish

What carries the argument

The argument rests on the equivalent-photon (Weizsäcker–Williams) description: a relativistic nucleus carries a pancake of virtual photons whose flux is set by the charge Z and the impact-parameter cutoff b>2R_A, with energy up to about gamma hbar c / b. That flux drives (1) photoproduction, where a photon from one ion interacts with the other, and (2) two-photon interactions. For diffractive photoproduction, the Good–Walker formalism separates coherent (target stays in ground state) from incoherent (nucleon/hotspot) production, relating the former to the average gluon density and the latter to its fluctuations; the two-source interference amplitude then connects the observed pT and rapidity

Load-bearing premise

The load-bearing premise is that coherent and incoherent photoproduction can be cleanly separated by whether the target nucleus remains in its ground state, and that each exchanged photon acts independently (factorization); the review itself states in Sec. 3.1.1 that it is not clear how this works in quantum field theory, and in Sec. 2.3 that factorization fails for incoherent production.

What would settle it

A precise measurement of the pT spectrum of coherent-like rho photoproduction in events with nuclear breakup, compared to the Good–Walker prediction, could falsify the coherence classification; alternatively, a violation of the factorization relation (Eq. 9) at high transverse momentum would invalidate the standard extraction of photonuclear cross sections using neutron tagging.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Photonuclear cross sections for coherent J/psi on protons and nuclei now span three orders of magnitude in x, giving a direct handle on the low-x gluon distribution and a baseline for saturation searches.
  • Two-photon production of tau pairs at the LHC places the current best limits on the tau anomalous magnetic moment and electric dipole moment.
  • Light-by-light scattering has been observed in lead–lead UPCs, and the same channel provides the most sensitive axion-like-particle search for masses roughly 5–90 GeV.
  • Coherent photoproduction of rho mesons acts as a two-source interferometer; the azimuthal asymmetry it produces enables precision measurements of hadronic radii and neutron-skin thickness.
  • Planned higher-energy colliders would extend this program to x ~ 10^-7 and open new kinematic windows for beyond-standard-model searches.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If the Good–Walker distinction between coherent and incoherent production fails for events in which the target nucleus breaks up (as the low-pT peaks in breakup events suggest), then the extracted gluon-fluctuation signals and the shadowing/saturation separation would need to be revisited; the review itself flags this as an open conceptual problem.
  • The review's use of factorization to remove the two-fold photon-energy ambiguity rests on Eq. 9; a violation at larger pT, hinted by existing data, would require new unfolding techniques for exclusive photoproduction.
  • The near-linear scaling of rho photoproduction with atomic number A sits between the coherent A^(4/3) and black-disk A^(2/3) limits; extending these measurements to a wider range of nuclei (including neutron-rich isotopes) could map the transition from shadowing to saturation.
  • Manuscript flag: Eq. 29, the Breit–Wheeler pair-production cross section, carries an in-text 'check equation' note; if that formula contains an error, the quantitative two-photon luminosity comparisons would need to be rechecked.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

3 major / 6 minor

Summary. This manuscript is a commissioned-style review of ultra-peripheral collisions (UPCs) at RHIC and the LHC, covering the equivalent-photon flux, photonuclear vector-meson photoproduction as a probe of nuclear structure and saturation, two-photon processes (dileptons, tau pairs, light-by-light, ALPs, monopoles), and quantum interference between photon sources. The organizing claim is that UPCs are the energy frontier for photon physics, reaching photon–nucleon center-of-mass energies above HERA and probing Bjorken-x down to 10^-6 for protons and 10^-5 for nuclei. The review is largely a synthesis of published experimental results and model comparisons, and it is candid about tensions, such as the ATLAS/ALICE midrapidity J/psi discrepancy, the difficulty of distinguishing shadowing from saturation, and the conceptual issues with the Good–Walker classification of coherence.

Significance. If the formulas and references are corrected, this would be a valuable and timely archival reference. The review's strengths are its breadth, its honest treatment of model failures and open questions, and its useful compilation of recent LHC and RHIC results, including very new measurements. It also gives appropriate attention to emerging topics such as subnucleonic gluon fluctuations, impact-parameter-dependent nuclear PDFs, and two-source quantum interference. The paper does not present new data or a new derivation, so its significance rests on accuracy and completeness as a survey. That significance is real but conditional on the technical soundness of the printed formulas, since the review explicitly aims to be a usable reference for the field.

major comments (3)
  1. [Sec. 4.2, Eq. (29)] Equation (29), the Breit–Wheeler cross section, is not usable as printed. The text immediately following the equation reads 'check equation', indicating that the authors have not verified it, and the logarithmic term is missing required parentheses/brackets. This equation is used in the discussion of gamma-gamma to lepton-pair production and is compared with ATLAS data in Sec. 4.2. For a review that is intended as an archival reference, a core cross-section formula cannot be left in an unverified, unreproducible state. This must be corrected and checked against a standard reference.
  2. [Sec. 5, Eq. (32)] Equation (32), the two-source interference amplitude central to Section 5, is malformed. The phase factors are written as e^{-phi2} instead of e^{i phi2}, and the k_perp·b exponent is missing the imaginary unit. As printed, the equation is not a valid quantum-mechanical amplitude and cannot be used to derive the interference effects described in the text, including the EPR-like discussion. Since this equation is the basis for the review's claims about two-source interferometry and nuclear radius measurements, it must be corrected and the surrounding discussion checked for consistency.
  3. [Sec. 3.1.1 and Sec. 2.3] The review is properly cautious about the Good–Walker formalism and the factorization assumption, and those caveats are acknowledged rather than hidden. However, the manuscript still leans heavily on the coherent/incoherent separation for several physics claims, especially the interpretation of gluon-density fluctuations in Sec. 3.1.9. Given that the review itself states 'it is not clear how it works in quantum field theory' and notes unexplained lead-versus-gold behavior, the conclusions built on this separation should be framed with an explicit statement that a failure of the Good–Walker classification would require reinterpreting those signals. The current text does note some of this, but the implications for the fluctuation claims could be stated more directly.
minor comments (6)
  1. [Sec. 2.4] The abbreviation 'GDP' is used where 'GDR' (Giant Dipole Resonance) is meant. Please correct.
  2. [Table 1 and Sec. 1] Table 1 lists Max W_gamma-p for PbPb as 750 GeV, while the text in Sec. 1 states 700 GeV. Please harmonize.
  3. [Sec. 2] There is a typo in the text: 'expected fro relativistic particles' should be 'for'.
  4. [Sec. 3.1.8, Eq. (25)] The text calls J0 a 'modified Bessel function'; it is the ordinary Bessel function of the first kind. The symbol J0 is used correctly in the integral, but the wording is wrong.
  5. [References] The citation 'Klein, Spencer and others (2020)' is malformed; the author list should be formatted consistently. Also check the style of the arXiv identifiers for consistency.
  6. [Sec. 6] The phrase 'theorist are attempting' should be 'theorists are attempting'.

Circularity Check

0 steps flagged

No circularity: the review is anchored by external measurements and benchmarked models; flagged formula defects are verification issues, not circular reductions.

full rationale

This is a review article, not a derivation, and its central assertions—UPCs are the photon-energy frontier, coherent J/psi photoproduction reaches x about 10^-6/10^-5, shadowing/saturation models are tested, two-photon processes constrain tau moments and ALPs, and two-source interference is observed—are anchored to measured results from HERA, RHIC (STAR/PHENIX), and LHC (ALICE/ATLAS/CMS/LHCb) collaborations and to accelerator parameters. The authors' self-citations (STARlight, nOOn, the Klein–Nystrand interference formalism, the Cepila–Contreras hot-spot model, and their previous reviews) are used to identify specific published tools and models, but each is benchmarked against external data or is a code-based generator; none functions as a uniqueness theorem or as an input that the review's conclusions recapitulate by construction. The unfolding in Eq. 15 is a standard inversion of measured rapidity distributions with computed photon fluxes, not a fitted parameter renamed as a prediction. The Good–Walker caveats in Sec. 3.1.1 are explicitly acknowledged, so the review does not conceal the fragility of the coherence classification; that is a physics risk, not a circular reduction. Formula defects (Eq. 29 contains the literal text '(check equation)' and Eq. 32 drops the imaginary unit in the phase factors) are real verification/copyediting problems that undermine the review's reference reliability, but they do not make the review's claims equivalent to their inputs. No circular step can be quoted.

Axiom & Free-Parameter Ledger

5 free parameters · 6 axioms · 5 invented entities

A review carries almost no independent epistemic load: every equation, parameter, and postulate in it is inherited from the cited literature. The paper introduces zero new free parameters, zero new entities, and zero new axioms. The entries above are the load-bearing inputs of the field as the review presents them: fitted exponents (delta, lambda, alpha_B) quoted as experimental results; form-factor parameters (Woods-Saxon, Yukawa range, dipole scale) used in quoted flux predictions; and the standard machinery (equivalent photon approximation, impact-parameter factorization, pomeron/Good-Walker, interference sign) plus the field's postulated objects (pomeron, hotspots, gluonic junction, ALP, monopole). The caveat specific to this review is that several generators and models it relies on (STARlight, nOOn, hot-spot model) were authored by the reviewers themselves; these are adequate anchors only because they are continuously tested against external LHC/RHIC/HERA data.

free parameters (5)
  • J/psi photoproduction power-law exponent delta = 0.70 ± 0.04
    Power-law fit to ALICE/HERA/LHCb data quoted in Sec. 3.1.3 and used via Eq. 23 to relate the J/psi slope to gluon growth; taken from the literature, not fitted here.
  • HERA gluon growth exponent lambda = 0.1 to 0.4 over Q^2 = 1 to 150 GeV^2
    Quoted from H1/ZEUS fits (Eq. 16) and used in Eq. 23; input from cited literature.
  • Baryon transport slope alpha_B = 1.04 ± 0.22
    STAR measurement in gamma-Au collisions (Eq. 26, Sec. 3.2.5) used to argue for gluonic-junction baryon transport; experimental fit quoted from literature.
  • Woods-Saxon parameters (R_WS, d) and Yukawa range a = R_WS ~ 1.2 A^(1/3), d ~ 0.53 fm, a = 0.7 fm
    Inputs to the nuclear form factor (Eqs. 5-6) that determine UPC photon flux predictions quoted throughout the review; standard values from electron-scattering fits.
  • Proton dipole form factor scale = 0.71 GeV^2
    Proton form factor parameter (Eq. 7) used for proton photon emitters in p-Pb and pp UPC predictions.
axioms (6)
  • standard math Equivalent-photon (Weizsaecker-Williams) approximation: the boosted electromagnetic field of an ion is a flux of quasi-real photons with the spectrum of Eq. 1.
    Foundational for every flux and cross-section statement in Secs. 2-6; standard QED result from von Weizsaecker (1934) and Williams (1934).
  • domain assumption Impact-parameter factorization: UPC cross sections factor as sigma = integral d^2b P1(b) P2(b) ... P_nohad(b) (Eq. 9), i.e., each exchanged photon does exactly one thing.
    Used to derive the mean-impact-parameter formulas (Eqs. 11-13) and the two-fold-ambiguity solution of Sec. 2.3; the review itself flags that factorization fails for incoherent photoproduction.
  • domain assumption Point-charge photon emitter for UPC flux with b > 2R_A; the nuclear charge distribution enters only via form factors.
    Stated in Sec. 2: 'This photon flux is calculated on the assumption that the nucleus acts as a point charge. This works well for UPCs.'
  • domain assumption Pomeron-exchange description of diffraction: diffractive vector meson production is mediated by a colorless two-gluon exchange, and x of the probe is m^2/W^2.
    Organizes all of Sec. 3.1 (Eqs. 17-20); standard soft/hard QCD modeling, not derived in the review.
  • domain assumption Good-Walker approach: coherent cross sections measure |<A>|^2, incoherent measure <|A|^2> - |<A>|^2, with sigma_coh + sigma_inc <= sigma_tot/2 (Eqs. 21-22).
    Underlies the review's interpretation of coherent/incoherent photoproduction and gluon fluctuations (Sec. 3.1.1); the review itself says 'it is not clear how it works in quantum field theory' and cites the lead/gold paradox as not understood.
  • domain assumption Destructive interference sign between the two photon-emission amplitudes for identical ions and its EPR interpretation (Eq. 32).
    The entire quantum-interferometry section (Sec. 5) depends on the sign convention arising from parity exchange; presented as established, though Eq. 32 is garbled as printed.
invented entities (5)
  • Pomeron no independent evidence
    purpose: Colorless carrier of diffractive interactions; the exchange object in all coherent photoproduction discussions of Sec. 3.1.
    Established effective description, not new to this paper; equivalent at lowest order to two gluons with vacuum quantum numbers.
  • Energy-dependent gluon hotspots no independent evidence
    purpose: Subnucleonic color-field fluctuations that generate incoherent/dissociative J/psi production (Secs. 3.1.1, 3.1.9; model GG-HS).
    Postulated structure from the Cepila-Contreras-Krelina hot-spot model; constrained only indirectly by the W and |t| dependence of incoherent production; the paper presents it as a modeling hypothesis.
  • Gluonic junction no independent evidence
    purpose: Gluon-field configuration carrying baryon number; invoked to explain the measured alpha_B ~ 1 baryon transport (Sec. 3.2.5).
    Attributed to Kharzeev (1996); the STAR measurement favors the junction hypothesis over valence-quark transport, but no direct probe of the junction exists.
  • Axion-like particle (ALP) independent evidence
    purpose: Hypothetical mediator in light-by-light scattering searched for in UPC data (Fig. 14).
    Search channel produces a gamma-gamma invariant-mass peak; ATLAS and CMS limits are quoted; a falsifiable handle exists outside the paper.
  • Magnetic monopole independent evidence
    purpose: Searched via the Schwinger mechanism in Pb-Pb UPCs (Sec. 4.6).
    Dirac charge quantization gives a clear falsifiable signature; MoEDAL and ATLAS limits are quoted.

pith-pipeline@v1.3.0-alltime-deepseek · 44374 in / 25555 out tokens · 266896 ms · 2026-08-01T15:09:03.245707+00:00 · methodology

0 comments
read the original abstract

Photons in ultra-peripheral collisions of heavy ions (and protons) can be used for a variety of physics purposes - for studies of nuclear structure at low Bjorken$-x$, as probes of beyond-standard-model physics at the highest possible photon energies, and to explore new regimes of quantum mechanics via interferometry between two photon sources that share no common origin. This review will present the origins of photons in ultra-peripheral collisions and discuss the important physics that is being done with these photons, with particular emphasis on those on the energy frontier for photon physics.

Figures

Figures reproduced from arXiv: 2607.18535 by Jesus Guillermo Contreras, Spencer Robert Klein.

Figure 1
Figure 1. Figure 1: (left) The electric (blue) and magnetic (red) fields of a relativistic ion are pancaked, and perpendicular to each other. That field may [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: (a) Diagram of diffractive coherent vector meson photoproduction in Pb–Pb collisions. One Pb nucleus emits a quasi-real photon that fluctuates into a quark-antiquark color dipole which interacts with the full color field of the second Pb nucleus through the exchange of a pomeron depicted by the dash lines. A vector meson is produced and both nuclei remain intact. In the case of incoherent production, the i… view at source ↗
Figure 3
Figure 3. Figure 3: Summary of experimental data on coherent J [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Summary of experimental data on coherent J [PITH_FULL_IMAGE:figures/full_fig_p009_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Summary of experimental data on coherent J [PITH_FULL_IMAGE:figures/full_fig_p010_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Left: Summary of experimental data on coherent [PITH_FULL_IMAGE:figures/full_fig_p011_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Left: Dipion mass distribution measured by the LHCb collaboration in Pb–Pb UPCs, and the contributions considered at the [PITH_FULL_IMAGE:figures/full_fig_p012_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Left: Mandelstam-t dependence of coherent diffractive production of ρ 0 in Au–Au UPCs. Middle: Fourier transform of the of the data in the left panel. These two figures were taken from [Adamczyk et al. (2017)]. Right: Mandelstam-t dependence of coherent diffractive production of J/ψ in Pb–Pb collisions. Taken from [Acharya et al. (2021c)]. overlaps [Klusek-Gawenda and Tapia Takaki (2020)]. This process may… view at source ↗
Figure 9
Figure 9. Figure 9: Energy and Mandelstam-t dependence of the cross section for incoherent diffractive J/ψ photonuclear production off Pb ions measured by the ALICE collaboration. Taken from [Acharya et al. (2025a)]. with the slope growing logarithmically with increasing interaction energy. This approach avoids some of the challenges presented by the Fourier-transform approach. 3.1.9 Fluctuations of nuclear structure As menti… view at source ↗
Figure 10
Figure 10. Figure 10: Left: Comparison of the measured triple-di [PITH_FULL_IMAGE:figures/full_fig_p015_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Comparison of the measured triple-differential cross section for inclusive jet production in photonuclear interactions at the LHC with predictions at leading order based on different nuclear PDFs. Taken from [Aad et al. (2025c)]. PDFs, is able to correctly describe data, with predictions undershooting the measurements in large regions of phase space. Discrepancies between data and predictions increase tow… view at source ↗
Figure 12
Figure 12. Figure 12: ATLAS data on γγ → µ +µ − . The top panel shows the azimuthal acoplanarity α = 1 − |δϕ|/π, for four different combinations of neutrons in their ZDCs, while the bottom panel shows the pair rapidity distribution for three different pair mass ranges. From [Aad et al. (2021a)]. momentum, the resulting beam of single-electron ions remains reasonably well collimated, depositing significant energy at a fairly sp… view at source ↗
Figure 13
Figure 13. Figure 13: Limits on the anomalous magnetic moment and electric dipole moment of the [PITH_FULL_IMAGE:figures/full_fig_p021_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: Two diagrams that can give rise to light-by-light scattering. The box diagram (left) has a loop that includes all electrically charged [PITH_FULL_IMAGE:figures/full_fig_p021_14.png] view at source ↗
Figure 7
Figure 7. Figure 7: 4.6 Monopole searches in two-photon interactions In 1931, Dirac proposed a model of a monopole, a particle that carries an isolated magnetic charge, as an infinitely thin and long solenoid. Using this scheme, he discovered that the monopole charge is quantized and related to the inversely proportional to the electric charge, which implies that the existence of a monopole would require charge quantization [… view at source ↗
Figure 15
Figure 15. Figure 15: (Left) The azimuthal asymmetries measured by STAR, for gold and uranium targets). The data is a good match to the theoretical [PITH_FULL_IMAGE:figures/full_fig_p023_15.png] view at source ↗

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

230 extracted references · 18 canonical work pages

  1. [2]

    and others

    Benedikt, M. and others. Future Circular Collider Feasibility Study Report: Volume 1, Physics, Experiments, Detectors. Eur. Phys. J. C. 2025. doi:10.1140/epjc/s10052-025-15077-x. arXiv:2505.00272

  2. [4]

    Letter of intent for ALICE 3: A next-generation heavy-ion experiment at the LHC

    Musa, Luciano and others. Letter of intent for ALICE 3: A next-generation heavy-ion experiment at the LHC. 2022. arXiv:2211.02491

  3. [9]

    Observation of nuclear suppression in coherent (1S) photoproduction off heavy nuclei at the LHC

    Belyaev, Andrey and others. Observation of nuclear suppression in coherent (1S) photoproduction off heavy nuclei at the LHC. 2026. arXiv:2604.05814

  4. [10]

    and Contreras, J

    Broz, M. and Contreras, J. G. and Tapia Takaki, J. D. A generator of forward neutrons for ultra-peripheral collisions: nOOn. Comput. Phys. Commun. 2020. doi:10.1016/j.cpc.2020.107181. arXiv:1908.08263

  5. [13]

    and Nystrand, Joakim and Vogt, Ramona

    Klein, Spencer R. and Nystrand, Joakim and Vogt, Ramona. Heavy quark photoproduction in ultraperipheral heavy ion collisions. Phys. Rev. C. 2002. doi:10.1103/PhysRevC.66.044906. arXiv:hep-ph/0206220

  6. [14]

    and Martins, Daniel E

    Gon c alves, Victor P. and Martins, Daniel E. and Rangel, Murilo S. and Tasevsky, Marek. Top quark pair production in the exclusive processes at the LHC. Phys. Rev. D. 2020. doi:10.1103/PhysRevD.102.074014. arXiv:2007.04565

  7. [15]

    and Nystrand, Joakim and Vogt, Ramona

    Klein, Spencer R. and Nystrand, Joakim and Vogt, Ramona. Photoproduction of top in peripheral heavy ion collisions. Eur. Phys. J. C. 2001. doi:10.1007/s100520100739. arXiv:hep-ph/0005157

  8. [16]

    Gon c alves, V. P. Photoproduction of top quarks in coherent hadron-hadron interactions. Phys. Rev. D. 2013. doi:10.1103/PhysRevD.88.054025

  9. [17]

    and Santana, Luana and Sch

    Goncalves, Victor P. and Santana, Luana and Sch. Inclusive heavy meson photoproduction in pPb and PbPb collisions. 2026. arXiv:2603.17612

  10. [18]

    Goncalves, V. P. and Machado, M. V. T. The QCD pomeron in ultraperipheral heavy ion collisions. 3. Photonuclear production of heavy quarks. Eur. Phys. J. C. 2003. doi:10.1140/epjc/s2003-01348-4. arXiv:hep-ph/0308120

  11. [19]

    Inclusive open charm photoproduction in ultraperipheral collisions at the LHC with in the generalized photon-nucleus fixed-order next-to-leading logarithm framework

    Cacciari, Matteo and Innocenti, Gian Michele and Sta \'s to, Anna M. Inclusive open charm photoproduction in ultraperipheral collisions at the LHC with in the generalized photon-nucleus fixed-order next-to-leading logarithm framework. Phys. Rev. D. 2025. doi:10.1103/1w13-r2tr. arXiv:2506.09893

  12. [20]

    Inclusive D0 photoproduction in ultraperipheral collisions

    Gimeno-Estivill, Patricia and Lappi, Tuomas and M. Inclusive D0 photoproduction in ultraperipheral collisions. Phys. Rev. D. 2025. doi:10.1103/7741-585p. arXiv:2503.16108

  13. [21]

    Measurement of D0 Meson Photoproduction in Ultraperipheral Heavy Ion Collisions

    Chekhovsky, Vladimir and others. Measurement of D0 Meson Photoproduction in Ultraperipheral Heavy Ion Collisions. Phys. Rev. Lett. 2026. doi:10.1103/lckg-sdh9. arXiv:2509.08626

  14. [23]

    Multiphoton exchange processes in ultraperipheral relativistic heavy ion collisions

    Baur, Gerhard and Hencken, Kai and Aste, Andreas and Trautmann, Dirk and Klein, Spencer R. Multiphoton exchange processes in ultraperipheral relativistic heavy ion collisions. Nucl. Phys. A. 2003. doi:10.1016/j.nuclphysa.2003.09.006. arXiv:nucl-th/0307031

  15. [24]

    and Nystrand, Joakim and Seger, Janet and Gorbunov, Yuri and Butterworth, Joey

    Klein, Spencer R. and Nystrand, Joakim and Seger, Janet and Gorbunov, Yuri and Butterworth, Joey. STARlight: A Monte Carlo simulation program for ultra-peripheral collisions of relativistic ions. Comput. Phys. Commun. 2017. doi:10.1016/j.cpc.2016.10.016. arXiv:1607.03838

  16. [32]

    Evidence of Spin-Interference Effects in Exclusive J/ e^+e^- Photoproduction in Ultraperipheral Heavy-Ion Collisions. 2025. arXiv:2512.02865

  17. [35]

    Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions

    Tumasyan, Armen and others. Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions. Phys. Rev. Lett. 2023. doi:10.1103/PhysRevLett.131.051901. arXiv:2205.00045

  18. [36]

    Anisotropy in Dijet Production in Exclusive and Inclusive Processes

    Hatta, Yoshitaka and Xiao, Bo-Wen and Yuan, Feng and Zhou, Jian. Anisotropy in Dijet Production in Exclusive and Inclusive Processes. Phys. Rev. Lett. 2021. doi:10.1103/PhysRevLett.126.142001. arXiv:2010.10774

  19. [39]

    Probing Gluon Fluctuations in Nuclei with the First Energy-Dependent Measurement of Incoherent J/ Photoproduction in Ultraperipheral PbPb Collisions

    Chekhovsky, Vladimir and others. Probing Gluon Fluctuations in Nuclei with the First Energy-Dependent Measurement of Incoherent J/ Photoproduction in Ultraperipheral PbPb Collisions. Phys. Rev. Lett. 2025. doi:10.1103/w9kp-f8xr. arXiv:2503.08903

  20. [40]

    Contreras, J. G. Gluon shadowing at small x from coherent J/ photoproduction data at energies available at the CERN Large Hadron Collider. Phys. Rev. C. 2017. doi:10.1103/PhysRevC.96.015203. arXiv:1610.03350

  21. [41]

    Observation of Coherent (1020) Meson Photoproduction in Ultraperipheral PbPb Collisions at sNN=5.36 \, \, TeV

    Chekhovsky, Vladimir and others. Observation of Coherent (1020) Meson Photoproduction in Ultraperipheral PbPb Collisions at sNN=5.36 \, \, TeV. Phys. Rev. Lett. 2025. doi:10.1103/2ssw-wwyy. arXiv:2504.05193

  22. [44]

    and others

    Citron, Z. and others. 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. 2019. doi:10.23731/CYRM-2019-007.1159. arXiv:1812.06772

  23. [53]

    Measurement of exclusive (770)^0 photoproduction in ultraperipheral pPb collisions at s_NN = 5.02 TeV

    Sirunyan, Albert M and others. Measurement of exclusive (770)^0 photoproduction in ultraperipheral pPb collisions at s_NN = 5.02 TeV. Eur. Phys. J. C. 2019. doi:10.1140/epjc/s10052-019-7202-9. arXiv:1902.01339

  24. [55]

    and others

    Sirunyan, Albert M. and others. Measurement of exclusive photoproduction from protons in pPb collisions at s_NN = 5.02 TeV. Eur. Phys. J. C. 2019. doi:10.1140/epjc/s10052-019-6774-8. arXiv:1809.11080

  25. [59]

    and Strikman, M

    Guzey, V. and Strikman, M. and Zhalov, M. Disentangling coherent and incoherent quasielastic J/ photoproduction on nuclei by neutron tagging in ultraperipheral ion collisions at the LHC. Eur. Phys. J. C. 2014. doi:10.1140/epjc/s10052-014-2942-z. arXiv:1312.6486

  26. [60]

    and Nystrand, Joakim

    Klein, Spencer R. and Nystrand, Joakim. Does particle decay cause wave function collapse: An Experimental test. Phys. Lett. A. 2003. doi:10.1016/S0375-9601(03)00076-8. arXiv:quant-ph/0206060

  27. [61]

    and Xu, Zhangbu and Yang, Shuai and Zha, Wangmei and Zhou, Jian

    Brandenburg, James Daniel and Klein, Spencer R. and Xu, Zhangbu and Yang, Shuai and Zha, Wangmei and Zhou, Jian. Probing quantum phenomena through photoproduction in relativistic heavy-ion collisions. Prog. Part. Nucl. Phys. 2025. doi:10.1016/j.ppnp.2025.104174. arXiv:2504.18342

  28. [62]

    Azimuthal angular entanglement between decaying particles in ultra-peripheral ion collisions

    Klein, Spencer R. Azimuthal angular entanglement between decaying particles in ultra-peripheral ion collisions. 2026. arXiv:2601.22212

  29. [63]

    Quantum mechanical aspects of coherent photoproduction: the limits of coherence, and multiple vector mesons

    Klein, Spencer R. Quantum mechanical aspects of coherent photoproduction: the limits of coherence, and multiple vector mesons. Phys. Proc. UPC. 2024. doi:10.17161/xdb61m86. arXiv:2404.04450

  30. [66]

    An introduction to PYTHIA 8.2

    Sj. An introduction to PYTHIA 8.2. Comput. Phys. Commun. 2015. doi:10.1016/j.cpc.2015.01.024. arXiv:1410.3012

  31. [67]

    Vermaseren, J. A. M. Two Photon Processes at Very High-Energies. Nucl. Phys. B. 1983. doi:10.1016/0550-3213(83)90336-X

  32. [68]

    Klein, Spencer and Mueller, A. H. and Xiao, Bo-Wen and Yuan, Feng. Lepton Pair Production Through Two Photon Process in Heavy Ion Collisions. Phys. Rev. D. 2020. doi:10.1103/PhysRevD.102.094013. arXiv:2003.02947

  33. [69]

    Klein, Spencer and Mueller, A. H. and Xiao, Bo-Wen and Yuan, Feng. Acoplanarity of a Lepton Pair to Probe the Electromagnetic Property of Quark Matter. Phys. Rev. Lett. 2019. doi:10.1103/PhysRevLett.122.132301. arXiv:1811.05519

  34. [72]

    Photoproduction and detection of ' + - + - decays in ultraperipheral collisions and at an electron-ion collider

    Devi, Neha and Seger, Janet and Kim, Minjung and Klein, Spencer R. Photoproduction and detection of ' + - + - decays in ultraperipheral collisions and at an electron-ion collider. Phys. Rev. C. 2026. doi:10.1103/wpbg-h511. arXiv:2505.00916

  35. [73]

    A Decade of Collectivity in Small Systems

    Grosse-Oetringhaus, Jan Fiete and Wiedemann, Urs Achim. A Decade of Collectivity in Small Systems. 2024. arXiv:2407.07484

  36. [75]

    and Ji, Yuanjing and Dong, Xin and Kim, Minjung

    Sweger, Zachary and Yoo, Saeahram and Zeng, Ziyuan and Cebra, Daniel and Klein, Spencer R. and Ji, Yuanjing and Dong, Xin and Kim, Minjung. Modeling backward-angle (u-channel) virtual Compton scattering at the future Electron-Ion Collider. Phys. Rev. C. 2023. doi:10.1103/PhysRevC.108.055205. arXiv:2308.10478

  37. [76]

    Ayerbe and others

    Gayoso, C. Ayerbe and others. Progress and opportunities in backward angle (u-channel) physics. Eur. Phys. J. A. 2021. doi:10.1140/epja/s10050-021-00625-2. arXiv:2107.06748

  38. [77]

    Observation of in proton-proton collisions and limits on the anomalous electromagnetic moments of the lepton

    Hayrapetyan, Aram and others. Observation of in proton-proton collisions and limits on the anomalous electromagnetic moments of the lepton. Rept. Prog. Phys. 2024. doi:10.1088/1361-6633/ad6fcb. arXiv:2406.03975

  39. [78]

    Observation of lepton pair production in ultraperipheral lead-lead collisions at s_NN = 5.02 TeV

    Tumasyan, Armen and others. Observation of lepton pair production in ultraperipheral lead-lead collisions at s_NN = 5.02 TeV. Phys. Rev. Lett. 2023. doi:10.1103/PhysRevLett.131.151803. arXiv:2206.05192

  40. [79]

    Bound-Free Pair Production in LHC Pb-Pb Operation at 6.37 Z TeV per Beam

    Jowett, John and Auchmann, Bernhard and Bahamonde Castro, Cristina and Kalliokoski, Matti and Lechner, Anton and Mertens, Tom and Schaumann, Michaela and Xu, Chen. Bound-Free Pair Production in LHC Pb-Pb Operation at 6.37 Z TeV per Beam. 7th International Particle Accelerator Conference. 2016. doi:10.18429/JACoW-IPAC2016-TUPMW028

  41. [80]

    and Christian, D

    Blanford, G. and Christian, D. C. and Gollwitzer, K. and Mandelkern, M. and Munger, C. T. and Schultz, J. and Zioulas, G. Observation of atomic anti-hydrogen. Phys. Rev. Lett. 1998. doi:10.1103/PhysRevLett.80.3037

  42. [81]

    and others

    Baur, G. and others. Production of anti--hydrogen. Phys. Lett. B. 1996. doi:10.1016/0370-2693(96)00005-6

  43. [82]

    Production of QED pairs at small impact parameter in relativistic heavy ion collisions

    Hencken, Kai and Baur, Gerhard and Trautmann, Dirk. Production of QED pairs at small impact parameter in relativistic heavy ion collisions. Phys. Rev. C. 2004. doi:10.1103/PhysRevC.69.054902. arXiv:nucl-th/0402061

  44. [83]

    Ivanov, D. Yu. and Schiller, A. and Serbo, V. G. Large Coulomb corrections to the e+ e- pair production at relativistic heavy ion colliders. Phys. Lett. B. 1999. doi:10.1016/S0370-2693(99)00323-8. arXiv:hep-ph/9809449

  45. [84]

    and Jackson, John David

    Cahn, Robert N. and Jackson, John David. Realistic equivalent photon yields in heavy ion collisions. Phys. Rev. D. 1990. doi:10.1103/PhysRevD.42.3690

  46. [85]

    Coherent Higgs Production in Relativistic Heavy Ion Collisions

    Papageorgiu, Elena. Coherent Higgs Production in Relativistic Heavy Ion Collisions. Phys. Rev. D. 1989. doi:10.1103/PhysRevD.40.92

  47. [86]

    Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at s_NN = 5.02 TeV

    Sirunyan, Albert M and others. Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at s_NN = 5.02 TeV. Phys. Lett. B. 2019. doi:10.1016/j.physletb.2019.134826. arXiv:1810.04602

  48. [90]

    and Labont \'e , Mathias C

    Klein, Spencer R. and Labont \'e , Mathias C. and Sweger, Zachary and Miller, Gerald A. and Vogt, Ramona. Imaging baryon number density within the proton. 2026. arXiv:2603.03730

  49. [91]

    and Greiner, M

    Vidovic, M. and Greiner, M. and Best, C. and Soff, G. Impact parameter dependence of the electromagnetic particle production in ultrarelativistic heavy ion collisions. Phys. Rev. C. 1993. doi:10.1103/PhysRevC.47.2308

  50. [92]

    and Szczurek, Antoni

    Klusek-Gawenda, Mariola and Goncalves, Victor P. and Szczurek, Antoni. Light-by-Light scattering in ultraperipheral heavy ion collisions: Estimating inelastic contributions. Phys. Lett. B. 2025. doi:10.1016/j.physletb.2025.139614. arXiv:2503.08624

  51. [93]

    Can gluons trace baryon number?

    Kharzeev, D. Can gluons trace baryon number?. Phys. Lett. B. 1996. doi:10.1016/0370-2693(96)00435-2. arXiv:nucl-th/9602027

  52. [94]

    New probes of nuclear gluon dynamics through photoproduction of charm in inelastic ultra-peripheral PbPb collisions with ALICE

    Nese, Sigurd. New probes of nuclear gluon dynamics through photoproduction of charm in inelastic ultra-peripheral PbPb collisions with ALICE. EPJ Web Conf. 2026. doi:10.1051/epjconf/202636413001. arXiv:2509.11814

  53. [95]

    and Klein, S

    Zha, W. and Klein, S. R. and Ma, R. and Ruan, L. and Todoroki, T. and Tang, Z. and Xu, Z. and Yang, C. and Yang, Q. and Yang, S. Coherent J/ photoproduction in hadronic heavy-ion collisions. Phys. Rev. C. 2018. doi:10.1103/PhysRevC.97.044910. arXiv:1705.01460

  54. [96]

    and others

    Vannucci, F. and others. Evidence for Two Processes at the ISR. Lect. Notes Phys. 1980

  55. [97]

    Electromagnetic production of Higgs bosons, SUSY particles, glueballs and mesons in ultrarelativistic heavy ion collisions

    Greiner, Martin and Vidovic, Mario and Soff, Gerhard. Electromagnetic production of Higgs bosons, SUSY particles, glueballs and mesons in ultrarelativistic heavy ion collisions. Phys. Rev. C. 1993. doi:10.1103/PhysRevC.47.2288

  56. [98]

    Gluons and the quark sea at high energies: Distributions, polarization, tomography

    Boer, Daniel and others. Gluons and the quark sea at high energies: Distributions, polarization, tomography. 2011. arXiv:1108.1713

  57. [99]

    Exclusive diffractive processes in electron-ion collisions

    Toll, Tobias and Ullrich, Thomas. Exclusive diffractive processes in electron-ion collisions. Phys. Rev. C. 2013. doi:10.1103/PhysRevC.87.024913. arXiv:1211.3048

  58. [100]

    Using coherent dipion photoproduction to image gold nuclei

    Klein, Spencer R. Using coherent dipion photoproduction to image gold nuclei. SciPost Phys. Proc. 2022. doi:10.21468/SciPostPhysProc.8.128. arXiv:2107.10447

  59. [101]

    Exclusive photon-photon production of muon pairs in proton-proton collisions at s =7 TeV

    Chatrchyan, Serguei and others. Exclusive photon-photon production of muon pairs in proton-proton collisions at s =7 TeV. JHEP. 2012. doi:10.1007/JHEP01(2012)052. arXiv:1111.5536

  60. [102]

    von Weizsacker, C. F. Radiation emitted in collisions of very fast electrons. Z. Phys. 1934. doi:10.1007/BF01333110

  61. [103]

    Williams, E. J. Nature of the high-energy particles of penetrating radiation and status of ionization and radiation formulae. Phys. Rev. 1934. doi:10.1103/PhysRev.45.729

  62. [104]

    , title=

    Fermi, E. , title=. Zeitschrift f. "1924" , month=

  63. [105]

    and Baur, Gerhard

    Bertulani, Carlos A. and Baur, Gerhard. Electromagnetic Processes in Relativistic Heavy Ion Collisions. Phys. Rept. 1988. doi:10.1016/0370-1573(88)90142-1

  64. [106]

    CEPC-SPPC Preliminary Conceptual Design Report

    Ahmad, Muhammd and others. CEPC-SPPC Preliminary Conceptual Design Report. 1. Physics and Detector. 2015

  65. [107]

    New opportunities at the photon energy frontier

    Klein, Spencer and others. New opportunities at the photon energy frontier. 2020. arXiv:2009.03838

  66. [108]

    Klein, Spencer R. and M. Imaging the nucleus with high-energy photons. Nature Rev. Phys. 2019. doi:10.1038/s42254-019-0107-6. arXiv:1910.10858

  67. [109]

    and Klein, Spencer R

    Bertulani, Carlos A. and Klein, Spencer R. and Nystrand, Joakim. Physics of ultra-peripheral nuclear collisions. Ann. Rev. Nucl. Part. Sci. 2005. doi:10.1146/annurev.nucl.55.090704.151526. arXiv:nucl-ex/0502005

  68. [110]

    Contreras, J. G. and Tapia Takaki, J. D. Ultra-peripheral heavy-ion collisions at the LHC. Int. J. Mod. Phys. A. 2015. doi:10.1142/S0217751X15420129

  69. [112]

    Ultraperipheral nuclear collisions

    Klein, Spencer and Nystrand, Joakim. Ultraperipheral nuclear collisions. Phys. Today. 2017. doi:10.1063/PT.3.3727

  70. [113]

    ON THE PRODUCTION OF ELECTRONS AND POSITRONS BY A COLLISION OF TWO PARTICLES

    Landau, Lev Davidovich and Lifschitz, Evgeny Mikhailovich. ON THE PRODUCTION OF ELECTRONS AND POSITRONS BY A COLLISION OF TWO PARTICLES. Phys. Z. Sowjetunion. 1934. doi:10.1016/B978-0-08-010586-4.50021-3

  71. [116]

    Light-by-light scattering in ultraperipheral collisions of heavy ions at two future detectors

    Jucha, Pawe and K usek-Gawenda, Mariola and Szczurek, Antoni. Light-by-light scattering in ultraperipheral collisions of heavy ions at two future detectors. Phys. Rev. D. 2024. doi:10.1103/PhysRevD.109.014004. arXiv:2308.01550

  72. [117]

    Coherent gamma gamma and gamma-A interactions in very peripheral collisions at relativistic ion colliders

    Baur, Gerhard and Hencken, Kai and Trautmann, Dirk and Sadovsky, Serguei and Kharlov, Yuri. Coherent gamma gamma and gamma-A interactions in very peripheral collisions at relativistic ion colliders. Phys. Rept. 2002. doi:10.1016/S0370-1573(01)00101-6. arXiv:hep-ph/0112211

  73. [118]

    Two photon physics in nucleus-nucleus collisions at RHIC

    Nystrand, Joakim and Klein, Spencer. Two photon physics in nucleus-nucleus collisions at RHIC. Workshop on Photon Interactions and the Photon Structure. 1998. arXiv:nucl-ex/9811007

  74. [119]

    and Ferreira Filho, L

    Baur, G. and Ferreira Filho, L. G. COHERENT PARTICLE PRODUCTION AT RELATIVISTIC HEAVY ION COLLIDERS INCLUDING STRONG ABSORPTION EFFECTS. Nucl. Phys. A. 1990. doi:10.1016/0375-9474(90)90191-N

  75. [120]

    Comment on '' _c production in photon-induced interactions at the LHC''

    Klein, Spencer R. Comment on '' _c production in photon-induced interactions at the LHC''. Phys. Rev. D. 2018. doi:10.1103/PhysRevD.98.118501. arXiv:1808.08253

  76. [122]

    Photonuclear and Two-photon Interactions at High-Energy Nuclear Colliders

    Klein, Spencer and Steinberg, Peter. Photonuclear and Two-photon Interactions at High-Energy Nuclear Colliders. Ann. Rev. Nucl. Part. Sci. 2020. doi:10.1146/annurev-nucl-030320-033923. arXiv:2005.01872

  77. [124]

    Tracking the baryon number with nuclear collisions

    STAR Collaboration. Tracking the baryon number with nuclear collisions. 2024. arXiv:2408.15441

  78. [127]

    and Contreras, J

    Cepila, J. and Contreras, J. G. and Vaculciak, M. Exclusive quarkonium photoproduction: Predictions with the Balitsky-Kovchegov equation including the full impact-parameter dependence. Phys. Rev. D. 2025. doi:10.1103/PhysRevD.111.056002. arXiv:2501.09462

  79. [128]

    Ratio of J/ and (2s) exclusive photoproduction cross sections as an indicator for the presence of nonlinear QCD evolution

    Peredo, Marco Alcazar and Hentschinski, Martin. Ratio of J/ and (2s) exclusive photoproduction cross sections as an indicator for the presence of nonlinear QCD evolution. Phys. Rev. D. 2024. doi:10.1103/PhysRevD.109.014032. arXiv:2308.15430

  80. [129]

    Klusek-Gawenda, Mariola and Tapia Takaki, J. Daniel. Exclusive Four-pion Photoproduction in Ultra-peripheral Heavy-ion Collisions at RHIC and LHC Energies. Acta Phys. Polon. B. 2020. doi:10.5506/APhysPolB.51.1393. arXiv:2005.13624

Showing first 80 references.