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arxiv: 2606.20327 · v1 · pith:KEGCOJK2new · submitted 2026-06-18 · ✦ hep-ph · hep-ex

Theory Calculations for LDMX and LOHENGRIN beyond Coherent Bethe-Heitler Scattering

Pith reviewed 2026-06-26 16:44 UTC · model grok-4.3

classification ✦ hep-ph hep-ex
keywords dark photonsLDMXLOHENGRINBethe-Heitlerbremsstrahlungincoherent scatteringdiffractive scatteringmissing momentum
0
0 comments X

The pith

Calculations beyond coherent Bethe-Heitler scattering show limited effects on dark photon signals for LDMX and LOHENGRIN, except requiring HCAL extension for LOHENGRIN.

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

This paper computes the differential cross sections for all real emission processes contributing to dark photon production in electron-nucleus scattering, going beyond the usual coherent Bethe-Heitler approximation by including incoherent and diffractive channels from nuclei and nucleons. It incorporates couplings to both electrons and hadrons and accounts for virtual contributions as well. The results indicate that with realistic experimental selections, these additional processes have only a limited effect on the predicted signal and background rates in the MeV to GeV dark photon mass range. However, for the LOHENGRIN experiment, diffractive scattering backgrounds necessitate an extension of its hadronic calorimeter to maintain effective vetoing. A sympathetic reader would care because precise background modeling is essential for the sensitivity of missing-momentum searches for light dark matter.

Core claim

The central claim is that the contributions beyond coherent Bethe-Heitler scattering, including scattering off nuclear constituents and diffractive processes, have only a limited effect on the predicted signal and background in the relevant dark photon mass range when realistic experimental selections are applied. The LOHENGRIN experiment will require an extension of its HCAL to effectively veto background processes from diffractive scattering.

What carries the argument

Differential cross sections for real emission processes up to third order in the electromagnetic fine structure constant and fourth order in the kinetic mixing parameter, including incoherent and diffractive contributions from target nucleus and constituents.

If this is right

  • The LOHENGRIN experiment requires an extension of its HCAL to veto diffractive scattering backgrounds.
  • Contributions beyond coherent Bethe-Heitler have limited effect on signal and background predictions for LDMX and LOHENGRIN under realistic cuts.
  • Virtual dark photon contributions are considered but do not alter the limited impact conclusion.
  • Signal characteristics of the recoiling electron remain largely as in coherent approximation.

Where Pith is reading between the lines

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

  • This implies that coherent-only calculations may suffice for approximate sensitivity estimates in similar experiments.
  • Extensions to other phase space regions or higher energies could reveal larger effects from these processes.
  • Precise inclusion of these terms could improve background rejection strategies in future dark matter searches.

Load-bearing premise

The phase space regions and experimental constraints are assumed sufficient to capture all relevant contributions, and the truncation at third order in the fine-structure constant and fourth in kinetic mixing misses no altering effects.

What would settle it

An experimental observation of diffractive scattering background rates in LOHENGRIN that cannot be vetoed without HCAL extension, or a calculation showing significant changes in signal efficiency from higher-order terms outside the considered orders.

read the original abstract

The Light Dark Matter eXperiment (LDMX), DarkSHINE, and LOHENGRIN are proposed new experiments. They aim to search for missing momentum signals sourced by the direct production of dark photons with masses in the MeV-GeV range in bremsstrahlung processes, in which an electron beam of a few GeV scatters off a fixed target. So far, the signal characteristics, i.e. the behavior of the recoiling electron, have mostly been studied in coherent Bethe-Heitler electron-nucleus scattering with a dark photon that couples only to the Standard Model charged leptons. In this work, we present the calculations of the differential cross sections of all contributing real emission processes up to third order in the electromagnetic fine structure constant and fourth order in the kinetic mixing parameter associated with the dark photon. We consider a dark photon coupling to both the beam electron and the hadronic target and we take into account the scattering off both the target nucleus and its nuclear constituents. Besides real emission processes, we also discuss virtual dark photon contributions and their relevance for the signal prediction. After discussing the different phase space regions and constraints emerging from the experimental setups, we show numerical results of the cross sections and differential distributions, including the signal and dominant background. Within our framework, we find that the LOHENGRIN experiment will require an extension of its HCAL to effectively veto background processes originating from diffractive scattering. Apart from that, the contributions beyond coherent Bethe-Heitler scattering, in the presence of realistic experimental selections, have only a limited effect on the predicted signal and background in the relevant dark photon mass range.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 0 minor

Summary. The paper calculates differential cross sections for real emission processes in dark photon production via electron bremsstrahlung off nuclei up to O(α³, ε⁴), including coherent/incoherent and leptonic/hadronic channels with a dark photon coupling to both electrons and hadrons. It also discusses virtual contributions and, after applying experimental phase-space constraints for LDMX, DarkSHINE and LOHENGRIN, concludes that beyond-coherent-Bethe-Heitler effects have only limited impact on signal and background in the relevant mass range, except that LOHENGRIN requires an HCAL extension to veto diffractive-scattering backgrounds.

Significance. If the order truncation and phase-space coverage are complete, the work supplies a more systematic perturbative input for background modeling in missing-momentum dark-photon searches, directly informing the design of the LOHENGRIN veto system and the robustness of sensitivity projections for all three experiments. The explicit treatment of nuclear constituents and higher-order real emissions is a concrete advance over the coherent Bethe-Heitler approximation used in prior studies.

major comments (1)
  1. [virtual contributions and numerical results sections] The central claim that beyond-coherent-Bethe-Heitler contributions have only limited effect (except for the LOHENGRIN HCAL recommendation) rests on the completeness of the retained O(α³, ε⁴) real-emission and virtual terms. The discussion of virtual contributions does not quantify their size relative to the kept orders inside the exact LOHENGRIN phase space after experimental selections; if O(ε⁶) interference or O(α⁴) processes become non-negligible in the diffractive or high-missing-momentum tails, both the limited-effect statement and the veto recommendation could shift.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their thorough review and for recognizing the systematic treatment of higher-order contributions as an advance over prior coherent Bethe-Heitler approximations. We address the single major comment below. We agree that explicit quantification of virtual terms inside the precise post-selection LOHENGRIN phase space was not provided and will strengthen that discussion in revision.

read point-by-point responses
  1. Referee: [virtual contributions and numerical results sections] The central claim that beyond-coherent-Bethe-Heitler contributions have only limited effect (except for the LOHENGRIN HCAL recommendation) rests on the completeness of the retained O(α³, ε⁴) real-emission and virtual terms. The discussion of virtual contributions does not quantify their size relative to the kept orders inside the exact LOHENGRIN phase space after experimental selections; if O(ε⁶) interference or O(α⁴) processes become non-negligible in the diffractive or high-missing-momentum tails, both the limited-effect statement and the veto recommendation could shift.

    Authors: We acknowledge that while the manuscript discusses virtual dark-photon contributions and their relevance (Section on virtual contributions), it does not supply explicit numerical ratios of O(ε⁶) or O(α⁴) terms relative to the retained O(α³, ε⁴) real-emission channels after the full LOHENGRIN experimental selections. Power counting indicates that O(ε⁶) interference is suppressed by an extra ε² (with ε ≲ 10^{-2}–10^{-3} in the probed range) and O(α⁴) by an additional factor of α ≈ 1/137, rendering both negligible even in the diffractive or high-missing-momentum tails relative to the leading terms. Nevertheless, we agree that a dedicated estimate inside the exact phase space would strengthen the central claim. In the revised manuscript we will add a short paragraph (or appendix) providing order-of-magnitude estimates for these higher-order pieces under the LOHENGRIN cuts, confirming that they remain below the percent level and do not alter the limited-impact conclusion or the HCAL-extension recommendation. No new calculations are required; the estimates follow directly from the existing coupling and phase-space analysis already presented. revision: yes

Circularity Check

0 steps flagged

No circularity: explicit perturbative cross-section calculations independent of fitted inputs or self-citation chains

full rationale

The paper computes differential cross sections for real emission and virtual processes up to O(α³ ε⁴) from first-principles QED matrix elements, incorporating coherent/incoherent scattering off nuclei and constituents, then applies experimental phase-space cuts to obtain numerical signal/background distributions. No step reduces a prediction to a fitted parameter by construction, invokes a self-citation as the sole justification for a uniqueness claim, or renames an empirical pattern; the limited-effect conclusion follows directly from the truncated perturbative results under the stated selections. The derivation is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 1 invented entities

Abstract-only review limits visibility into specific parameters or assumptions; the work rests on standard perturbative QED and the dark-photon model without new fitted quantities or entities introduced in the provided text.

axioms (2)
  • standard math Perturbative expansion of QED processes up to third order in the fine-structure constant
    Invoked to compute real emission cross sections
  • domain assumption Kinetic mixing between the dark photon and the ordinary photon
    Standard modeling assumption for dark-photon phenomenology
invented entities (1)
  • Dark photon no independent evidence
    purpose: Mediator particle carrying missing momentum in electron scattering
    Postulated within the dark-photon model; no new independent evidence supplied

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Works this paper leans on

78 extracted references · 2 canonical work pages

  1. [1]

    Bertone and D

    G. Bertone and D. Hooper,History of dark matter,Rev. Mod. Phys.90(2018) 045002 [1605.04909]

  2. [2]

    Battaglieri, A

    M. Battaglieri, A. Belloni, A. Chou, P. Cushman, B. Echenard, R. Essig et al.,Us cosmic visions: New ideas in dark matter 2017: Community report, 2017. [3]LDMXcollaboration,Light Dark Matter eXperiment (LDMX),1808.05219. [4]LDMXcollaboration,A High Efficiency Photon Veto for the Light Dark Matter eXperiment, JHEP04(2020) 003 [1912.05535]

  3. [3]

    ˚Akesson et al.,Current Status and Future Prospects for the Light Dark Matter eXperiment, inSnowmass 2021, 3, 2022 [2203.08192]

    T. ˚Akesson et al.,Current Status and Future Prospects for the Light Dark Matter eXperiment, inSnowmass 2021, 3, 2022 [2203.08192]. [6]LDMXcollaboration,Photon-rejection power of the Light Dark Matter eXperiment in an 8 GeV beam,JHEP12(2023) 092 [2308.15173]. [7]LDMXcollaboration,LDMX – The Light Dark Matter EXperiment,2508.11833. – 56 – [8]DarkSHINEcolla...

  4. [4]

    Bechtle et al.,A Proposal for the Lohengrin Experiment to Search for Dark Sector Particles at the ELSA Accelerator,2410.10956

    P. Bechtle et al.,A Proposal for the Lohengrin Experiment to Search for Dark Sector Particles at the ELSA Accelerator,2410.10956

  5. [5]

    Okun,LIMITS OF ELECTRODYNAMICS: PARAPHOTONS?,Sov

    L.B. Okun,LIMITS OF ELECTRODYNAMICS: PARAPHOTONS?,Sov. Phys. JETP56 (1982) 502

  6. [6]

    Holdom,TwoU(1)’s andεcharge shifts,Physics Letters B166(1986) 196

    B. Holdom,TwoU(1)’s andεcharge shifts,Physics Letters B166(1986) 196

  7. [7]

    Boehm and P

    C. Boehm and P. Fayet,Scalar dark matter candidates,Nucl. Phys. B683(2004) 219 [hep-ph/0305261]

  8. [8]

    Pospelov,Secluded U(1) below the weak scale,Phys

    M. Pospelov,Secluded U(1) below the weak scale,Phys. Rev. D80(2009) 095002 [0811.1030]

  9. [9]

    Filippi and M

    A. Filippi and M. De Napoli,Searching in the dark: the hunt for the dark photon,Rev. Phys. 5(2020) 100042 [2006.04640]

  10. [10]

    Fabbrichesi, E

    M. Fabbrichesi, E. Gabrielli and G. Lanfranchi,The Dark Photon,2005.01515

  11. [11]

    Dreiner, J.-F

    H.K. Dreiner, J.-F. Fortin, C. Hanhart and L. Ubaldi,Supernova constraints on MeV dark sectors frome +e−annihilations,Phys. Rev. D89(2014) 105015 [1310.3826]

  12. [12]

    Feng and J

    J.L. Feng and J. Kumar,The WIMPless Miracle: Dark-Matter Particles without Weak-Scale Masses or Weak Interactions,Phys. Rev. Lett.101(2008) 231301 [0803.4196]

  13. [13]

    Krnjaic,Testing Thermal-Relic Dark Matter with a Dark Photon Mediator,2505.04626

    G. Krnjaic,Testing Thermal-Relic Dark Matter with a Dark Photon Mediator,2505.04626

  14. [14]

    Battaglieri et al.,US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report, inU.S

    M. Battaglieri et al.,US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report, inU.S. Cosmic Visions: New Ideas in Dark Matter, 7, 2017 [1707.04591]

  15. [15]

    Feng and J

    J.L. Feng and J. Smolinsky,Impact of a resonance on thermal targets for invisible dark photon searches,Phys. Rev. D96(2017) 095022 [1707.03835]. [21]BaBarcollaboration,Search for Invisible Decays of a Dark Photon Produced ine +e− Collisions at BaBar,Phys. Rev. Lett.119(2017) 131804 [1702.03327]

  16. [16]

    Batell, R

    B. Batell, R. Essig and Z. Surujon,Strong Constraints on Sub-GeV Dark Sectors from SLAC Beam Dump E137,Phys. Rev. Lett.113(2014) 171802 [1406.2698]

  17. [17]

    deNiverville, M

    P. deNiverville, M. Pospelov and A. Ritz,Observing a light dark matter beam with neutrino experiments,Phys. Rev. D84(2011) 075020 [1107.4580]

  18. [18]

    Batell, M

    B. Batell, M. Pospelov and A. Ritz,Exploring Portals to a Hidden Sector Through Fixed Targets,Phys. Rev. D80(2009) 095024 [0906.5614]. [25]MiniBooNE DMcollaboration,Dark Matter Search in Nucleon, Pion, and Electron Channels from a Proton Beam Dump with MiniBooNE,Phys. Rev. D98(2018) 112004 [1807.06137]

  19. [19]

    Banerjee et al.,Dark matter search in missing energy events with NA64,Phys

    D. Banerjee et al.,Dark matter search in missing energy events with NA64,Phys. Rev. Lett. 123(2019) 121801 [1906.00176]

  20. [20]

    Alexander et al.,Dark Sectors 2016 Workshop: Community Report, inDark Sectors 2016 Workshop: Community Report, 8, 2016 [1608.08632]

    J. Alexander et al.,Dark Sectors 2016 Workshop: Community Report, inDark Sectors 2016 Workshop: Community Report, 8, 2016 [1608.08632]

  21. [21]

    Izaguirre, G

    E. Izaguirre, G. Krnjaic, P. Schuster and N. Toro,Testing GeV-Scale Dark Matter with Fixed-Target Missing Momentum Experiments,Phys. Rev. D91(2015) 094026 [1411.1404]. – 57 –

  22. [22]

    Izaguirre, G

    E. Izaguirre, G. Krnjaic, P. Schuster and N. Toro,Analyzing the Discovery Potential for Light Dark Matter,Phys. Rev. Lett.115(2015) 251301 [1505.00011]

  23. [23]

    Izaguirre, Y

    E. Izaguirre, Y. Kahn, G. Krnjaic and M. Moschella,Testing Light Dark Matter Coannihilation With Fixed-Target Experiments,Phys. Rev. D96(2017) 055007 [1703.06881]

  24. [24]

    J.B. Dent, F. Ferrer and L.M. Krauss,Constraints on Light Hidden Sector Gauge Bosons from Supernova Cooling,1201.2683

  25. [25]

    Dreiner, J.-F

    H.K. Dreiner, J.-F. Fortin, J. Isern and L. Ubaldi,White Dwarfs constrain Dark Forces, Phys. Rev. D88(2013) 043517 [1303.7232]

  26. [26]

    H. An, M. Pospelov and J. Pradler,New stellar constraints on dark photons,Phys. Lett. B 725(2013) 190 [1302.3884]

  27. [27]

    Redondo and G

    J. Redondo and G. Raffelt,Solar constraints on hidden photons re-visited,JCAP08(2013) 034 [1305.2920]

  28. [28]

    Sabti, J

    N. Sabti, J. Alvey, M. Escudero, M. Fairbairn and D. Blas,Refined Bounds on MeV-scale Thermal Dark Sectors from BBN and the CMB,JCAP01(2020) 004 [1910.01649]

  29. [29]

    Bethe and W

    H. Bethe and W. Heitler,On the Stopping of fast particles and on the creation of positive electrons,Proc. Roy. Soc. Lond. A146(1934) 83

  30. [30]

    von Weizsacker,Radiation emitted in collisions of very fast electrons,Z

    C.F. von Weizsacker,Radiation emitted in collisions of very fast electrons,Z. Phys.88 (1934) 612

  31. [31]

    Williams,Nature of the high-energy particles of penetrating radiation and status of ionization and radiation formulae,Phys

    E.J. Williams,Nature of the high-energy particles of penetrating radiation and status of ionization and radiation formulae,Phys. Rev.45(1934) 729

  32. [32]

    Blinov, G

    N. Blinov, G. Krnjaic and D. Tuckler,Characterizing Dark Matter Signals with Missing Momentum Experiments,Phys. Rev. D103(2021) 035030 [2010.03577]

  33. [33]

    Eichlersmith, J

    T. Eichlersmith, J. Mans, O. Moreno, J. Muse, M. Revering and N. Toro,Simulation of dark bremsstrahlung in Geant4,Comput. Phys. Commun.287(2023) 108690 [2211.03873]

  34. [34]

    Tsai,AXION BREMSSTRAHLUNG BY AN ELECTRON BEAM,Phys

    Y.-S. Tsai,AXION BREMSSTRAHLUNG BY AN ELECTRON BEAM,Phys. Rev. D34 (1986) 1326

  35. [35]

    Y.-S. Liu, D. McKeen and G.A. Miller,Validity of the Weizs¨ acker-Williams approximation and the analysis of beam dump experiments: Production of a new scalar boson,Phys. Rev. D 95(2017) 036010 [1609.06781]

  36. [36]

    Liu and G.A

    Y.-S. Liu and G.A. Miller,Validity of the Weizs¨ acker-Williams approximation and the analysis of beam dump experiments: Production of an axion, a dark photon, or a new axial-vector boson,Phys. Rev. D96(2017) 016004 [1705.01633]

  37. [37]

    Gninenko, D.V

    S.N. Gninenko, D.V. Kirpichnikov, M.M. Kirsanov and N.V. Krasnikov,The exact tree-level calculation of the dark photon production in high-energy electron scattering at the CERN SPS,Phys. Lett. B782(2018) 406 [1712.05706]

  38. [38]

    Ballett, M

    P. Ballett, M. Hostert, S. Pascoli, Y.F. Perez-Gonzalez, Z. Tabrizi and R. Zukanovich Funchal,Neutrino Trident Scattering at Near Detectors,JHEP01(2019) 119 [1807.10973]

  39. [39]

    Curtin, Y

    D. Curtin, Y. Kahn and R. Nguyen,Dark photons from charged pion bremsstrahlung at proton beam experiments,Phys. Rev. D108(2023) 095039 [2305.19309]. – 58 –

  40. [40]

    Fearing and S

    H.W. Fearing and S. Scherer,Virtual Compton scattering off spin zero particles at low-energies,Few Body Syst.23(1998) 111 [nucl-th/9607056]

  41. [41]

    Guichon, G.Q

    P.A.M. Guichon, G.Q. Liu and A.W. Thomas,Virtual Compton scattering and generalized polarizabilities of the proton,Nucl. Phys. A591(1995) 606 [nucl-th/9605031]

  42. [42]

    Scherer, A.Y

    S. Scherer, A.Y. Korchin and J.H. Koch,Virtual Compton scattering off the nucleon at low-energies,Phys. Rev. C54(1996) 904 [nucl-th/9605030]

  43. [43]

    Moinester and S

    M. Moinester and S. Scherer,Compton Scattering off Pions and Electromagnetic Polarizabilities,Int. J. Mod. Phys. A34(2019) 1930008 [1905.05640]

  44. [44]

    Thomson,Modern particle physics, Cambridge University Press, New York (10, 2013), 10.1017/CBO9781139525367

    M. Thomson,Modern particle physics, Cambridge University Press, New York (10, 2013), 10.1017/CBO9781139525367

  45. [45]

    L’vov, S

    A.I. L’vov, S. Scherer, B. Pasquini, C. Unkmeir and D. Drechsel,Generalized dipole polarizabilities and the spatial structure of hadrons,Phys. Rev. C64(2001) 015203 [hep-ph/0103172]

  46. [46]

    Martin and P

    M. Martin and P. Stelson,Nuclear data sheets for a=184,Nuclear Data Sheets21(1977) 1

  47. [47]

    Scherer and M.R

    S. Scherer and M.R. Schindler,A Primer for Chiral Perturbation Theory, vol. 830, Springer Berlin (2012), 10.1007/978-3-642-19254-8

  48. [48]

    Vanderhaeghen, J.M

    M. Vanderhaeghen, J.M. Friedrich, D. Lhuillier, D. Marchand, L. Van Hoorebeke and J. Van de Wiele,QED radiative corrections to virtual Compton scattering,Phys. Rev. C62 (2000) 025501 [hep-ph/0001100]

  49. [49]

    Djukanovic,Virtual Compton scattering in baryon chiral perturbation theory, Ph.D

    D. Djukanovic,Virtual Compton scattering in baryon chiral perturbation theory, Ph.D. thesis, Mainz U., 2008

  50. [50]

    Kelly,Simple parametrization of nucleon form factors,Phys

    J.J. Kelly,Simple parametrization of nucleon form factors,Phys. Rev. C70(2004) 068202

  51. [51]

    Kling, P

    F. Kling, P. Reimitz and A. Ritz,Dark Vector Boson Bremsstrahlung: New Form Factors for a Broader Class of Models,2509.09437

  52. [52]

    Foroughi-Abari and A

    S. Foroughi-Abari and A. Ritz,Dark sector production via proton bremsstrahlung,Phys. Rev. D105(2022) 095045 [2108.05900]

  53. [53]

    Gorbunov and E

    D. Gorbunov and E. Kriukova,Dark photon production via elastic proton bremsstrahlung with non-zero momentum transfer,JHEP01(2024) 058 [2306.15800]

  54. [54]

    Gorbunov and E

    D. Gorbunov and E. Kriukova,Pauli form factor contributions to the inelastic proton bremsstrahlung and dark photon production,JHEP02(2025) 018 [2409.11386]

  55. [55]

    Zhou and J.F

    B. Zhou and J.F. Beacom,Neutrino-nucleus cross sections for W-boson and trident production,Phys. Rev. D101(2020) 036011 [1910.08090]

  56. [56]

    Bodek,Pauli Blocking for a Relativistic Fermi Gas in Quasielastic Lepton Nucleus Scattering,2111.03631

    A. Bodek,Pauli Blocking for a Relativistic Fermi Gas in Quasielastic Lepton Nucleus Scattering,2111.03631

  57. [57]

    Hahn,Generating Feynman diagrams and amplitudes with FeynArts 3,Comput

    T. Hahn,Generating Feynman diagrams and amplitudes with FeynArts 3,Comput. Phys. Commun.140(2001) 418 [hep-ph/0012260]

  58. [58]

    Hahn and M

    T. Hahn and M. Perez-Victoria,Automatized one loop calculations in four-dimensions and D-dimensions,Comput. Phys. Commun.118(1999) 153 [hep-ph/9807565]

  59. [59]

    Mertig, M

    R. Mertig, M. Bohm and A. Denner,FEYN CALC: Computer algebraic calculation of Feynman amplitudes,Comput. Phys. Commun.64(1991) 345. – 59 –

  60. [60]

    Shtabovenko, R

    V. Shtabovenko, R. Mertig and F. Orellana,New Developments in FeynCalc 9.0,Comput. Phys. Commun.207(2016) 432 [1601.01167]

  61. [61]

    Shtabovenko, R

    V. Shtabovenko, R. Mertig and F. Orellana,FeynCalc 9.3: New features and improvements, Comput. Phys. Commun.256(2020) 107478 [2001.04407]

  62. [62]

    Christensen and C

    N.D. Christensen and C. Duhr,FeynRules - Feynman rules made easy,Comput. Phys. Commun.180(2009) 1614 [0806.4194]

  63. [63]

    Alloul, N.D

    A. Alloul, N.D. Christensen, C. Degrande, C. Duhr and B. Fuks,FeynRules 2.0 - A complete toolbox for tree-level phenomenology,Comput. Phys. Commun.185(2014) 2250 [1310.1921]

  64. [64]

    van Hameren,OneLOop: For the evaluation of one-loop scalar functions,Comput

    A. van Hameren,OneLOop: For the evaluation of one-loop scalar functions,Comput. Phys. Commun.182(2011) 2427 [1007.4716]

  65. [65]

    Denner,Techniques for calculation of electroweak radiative corrections at the one loop level and results for W physics at LEP-200,Fortsch

    A. Denner,Techniques for calculation of electroweak radiative corrections at the one loop level and results for W physics at LEP-200,Fortsch. Phys.41(1993) 307 [0709.1075]

  66. [66]

    Hahn,CUBA: A Library for multidimensional numerical integration,Comput

    T. Hahn,CUBA: A Library for multidimensional numerical integration,Comput. Phys. Commun.168(2005) 78 [hep-ph/0404043]

  67. [67]

    Y. Kahn, G. Krnjaic, N. Tran and A. Whitbeck,M 3: a new muon missing momentum experiment to probe (g−2)µand dark matter at Fermilab,JHEP09(2018) 153 [1804.03144]. [75]CALICEcollaboration,The CALICE SiW ECAL Technological Prototype—Status and Outlook,Instruments6(2022) 75 [2211.07457]

  68. [68]

    M. Wang, W. Huang, F. Kondev, G. Audi and S. Naimi,The ame 2020 atomic mass evaluation (ii). tables, graphs and references*,Chinese Physics C45(2021) 030003

  69. [69]

    Agostinelli, J

    S. Agostinelli, J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce et al.,Geant4 – a simulation toolkit,Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment506(2003) 250

  70. [70]

    Allison, K

    J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce Dubois, M. Asai et al.,Geant4 developments and applications,IEEE Transactions on Nuclear Science53(2006) 270

  71. [71]

    Allison, K

    J. Allison, K. Amako, J. Apostolakis, P. Arce, M. Asai, T. Aso et al.,Recent developments in geant4,Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment835(2016) 186

  72. [72]

    Ferrari, P

    A. Ferrari, P. Sala, A. Fasso and J. Ranft,Fluka: a multi-particle transport code,CERN Yellow report2005-10(2005)

  73. [73]

    B¨ ohlen, F

    T. B¨ ohlen, F. Cerutti, M. Chin, A. Fass` o, A. Ferrari, P. Ortega et al.,The fluka code: Developments and challenges for high energy and medical applications,Nuclear Data Sheets 120(2014) 211

  74. [74]

    O. Buss, T. Gaitanos, K. Gallmeister, H. van Hees, M. Kaskulov, O. Lalakulich et al., Transport-theoretical Description of Nuclear Reactions,Phys. Rept.512(2012) 1 [1106.1344]

  75. [75]

    Fuentes Zamoro, B

    M. Fuentes Zamoro, B. Grinstein and P. Qu´ ılez,Taming forward scattering singularities in partial waves,2510.08784

  76. [76]

    Kniehl,Elastic e p scattering and the Weizsacker-Williams approximation,Phys

    B.A. Kniehl,Elastic e p scattering and the Weizsacker-Williams approximation,Phys. Lett. B254(1991) 267. – 60 – [85]NA48/2collaboration,Search for the dark photon inπ 0 decays,Phys. Lett. B746(2015) 178 [1504.00607]. [86]BaBarcollaboration,Search for a Dark Photon ine +e−Collisions at BaBar,Phys. Rev. Lett.113(2014) 201801 [1406.2980]

  77. [77]

    Schuster, N

    P. Schuster, N. Toro and K. Zhou,Probing invisible vector meson decays with the NA64 and LDMX experiments,Phys. Rev. D105(2022) 035036 [2112.02104]

  78. [78]

    Kersevan and E

    B.P. Kersevan and E. Richter-Was,Improved phase space treatment of massive multi-particle final states,Eur. Phys. J. C39(2005) 439 [hep-ph/0405248]. [89]Particle Data Groupcollaboration,Review of particle physics,Phys. Rev. D110(2024) 030001. – 61 –