pith. sign in

arxiv: 2605.03014 · v1 · submitted 2026-05-04 · ✦ hep-ph · astro-ph.CO· hep-ex

Searching for UFOs from the early universe: direct detection prospects for relativistically decoupling dark matter

Stephen E. Henrich , Yann Mambrini , Keith A. Olive This is my paper

Pith reviewed 2026-05-08 17:50 UTC · model grok-4.3

classification ✦ hep-ph astro-ph.COhep-ex
keywords dark matterdirect detectionZ' portalrelativistic decouplingfreeze-outrelic densityneutrino fog
0
0 comments X

The pith

Current direct detection experiments have already ruled out much of the viable parameter space for ultrarelativistically decoupling dark matter in Z' portal models.

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

The paper examines dark matter particles that freeze out while still moving at relativistic speeds during the early universe reheating phase. These ultrarelativistically frozen-out candidates, or UFOs, arise naturally in models with heavy portal interactions and strong couplings at relatively low reheating temperatures. Using the Z' portal as a concrete example, the work calculates the resulting nucleon scattering cross sections and compares them to the sensitivities of existing and planned detectors. The central result is that current experiments have already excluded large regions of the allowed masses and couplings, while viable windows remain above the neutrino background and future runs will cover additional ground.

Core claim

Particles that decouple relativistically from the Standard Model bath during reheating represent a versatile class of well-motivated cold dark matter candidates. Ultrarelativistic decoupling is quite generic for beyond the Standard Model heavy portal interactions with strong couplings and relatively low reheating temperatures. Although typical UFO cross sections are suppressed by a heavy mediator mass scale, experiments such as LZ, XENONnT, PandaX, and DarkSide-50 have already excluded a large portion of the UFO parameter space and there remains viable space above the neutrino fog for 0.4 GeV ≲ m_DM ≲ 1 TeV. Moreover, SuperCDMS SNOLAB should access a large region of UFO parameter space in 0.

What carries the argument

Ultrarelativistic decoupling at temperature T_FO much greater than the dark matter mass m_χ, which fixes the relic abundance for strong couplings to a heavy Z' mediator while producing a calculable direct detection cross section.

If this is right

  • LZ, XENONnT, PandaX, and DarkSide-50 have already excluded large regions of UFO parameter space.
  • Viable UFO space remains above the neutrino fog for dark matter masses between roughly 0.4 GeV and 1 TeV.
  • SuperCDMS SNOLAB will probe a substantial additional slice of UFO parameter space in the 0.5-10 GeV mass window.
  • For mediator masses above about 1 TeV, UFO candidates produce larger direct detection rates than freeze-in candidates.
  • Certain mass and coupling regions exhibit degeneracy between UFO and non-relativistic freeze-out scenarios.

Where Pith is reading between the lines

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

  • Searches optimized for the softer recoil spectra expected from UFOs could extend sensitivity beyond standard WIMP analyses.
  • Confirmation of an UFO signal would directly constrain the reheating temperature and the strength of the portal coupling in the early universe.
  • The same decoupling mechanism may apply to other portal models, suggesting a broader class of targets for next-generation detectors.

Load-bearing premise

The assumption that ultrarelativistic decoupling occurs for strong couplings and relatively low reheating temperatures in the Z' portal model, and that the resulting direct detection cross sections can be reliably computed without significant additional effects from the early universe or detector specifics.

What would settle it

A measurement showing that the actual DM-nucleon scattering rate in the 0.4 GeV to 1 TeV range lies below the minimum cross section required to produce the observed relic density via ultrarelativistic decoupling in the Z' model.

read the original abstract

Particles that decouple relativistically from the Standard Model bath during reheating represent a versatile class of well-motivated cold dark matter candidates. In fact, ultrarelativistic decoupling ($T_{\rm FO}\gg m_\chi$) is quite generic for beyond the Standard Model (BSM) heavy portal interactions with strong couplings and relatively low reheating temperatures. In this work, we study the direct detection prospects for ultrarelativistically frozen-out (UFO) candidates, using $Z'$-portal dark matter as a case study. Although typical UFO cross sections are suppressed by a heavy mediator mass scale, we find that experiments such as LZ, XENONnT, PandaX, and DarkSide-50 have already excluded a large portion of the UFO parameter space and there remains viable space above the neutrino fog for $0.4 \text{ GeV} \lesssim m_{\rm DM}\lesssim 1$ TeV. Moreover, SuperCDMS SNOLAB, which is expected to begin collecting data in 2026, should access a large region of UFO parameter space in the 0.5-10 GeV mass range. For heavy BSM portal interactions ($M\gtrsim 1$ TeV), UFOs are typically more accessible to detection than freeze-in candidates due to the comparatively larger cross sections. We also carefully delineate regions of parameter space with degeneracy between UFO and non-relativistic freeze-out. In sum, UFOs are attractive candidates for ongoing and next-generation dark matter detection experiments in a looming post-WIMP era.

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

0 major / 3 minor

Summary. The paper examines direct detection prospects for ultrarelativistically frozen-out (UFO) dark matter in a Z'-portal model, where decoupling occurs at T_FO ≫ m_DM due to strong couplings and low reheating temperatures. It concludes that current experiments (LZ, XENONnT, PandaX, DarkSide-50) have excluded a substantial fraction of the UFO parameter space, with viable regions remaining above the neutrino fog for 0.4 GeV ≲ m_DM ≲ 1 TeV; SuperCDMS SNOLAB is projected to probe additional space in the 0.5-10 GeV range. The analysis also maps degeneracies between UFO and non-relativistic freeze-out regimes and notes that UFOs are typically more detectable than freeze-in candidates for heavy mediators (M ≳ 1 TeV).

Significance. If the relic density and cross-section calculations hold, the result is significant for identifying accessible DM targets in the post-WIMP era. The work supplies concrete exclusion regions and future projections that differentiate UFO behavior from standard freeze-out and freeze-in, highlighting how strong-coupling, low-reheating scenarios can yield detectable signals despite heavy-mediator suppression. Explicit parameter-space delineation and comparison to neutrino fog add practical value for experimental planning.

minor comments (3)
  1. The abstract and introduction use the informal phrase 'looming post-WIMP era'; a more precise formulation would improve formality.
  2. Figure captions (presumably in §4 or §5) should explicitly state the reheating temperature and coupling values used for the benchmark curves to aid reproducibility.
  3. Notation for the mediator mass M and DM mass m_DM is clear, but the text would benefit from a single consolidated table listing all free parameters and their ranges.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for their positive assessment of our work on ultrarelativistically decoupling dark matter and for recommending minor revision. We appreciate the recognition of the significance for post-WIMP direct detection prospects.

Circularity Check

0 steps flagged

No significant circularity; derivation is self-contained model calculation

full rationale

The paper computes relic density via standard ultrarelativistic decoupling in the Z'-portal model and derives direct-detection cross sections from the same parameters (m_DM, M, g), then compares the resulting rates to published experimental limits from LZ, XENONnT, etc. No step reduces a prediction to a fitted input by construction, no self-citation is invoked as a load-bearing uniqueness theorem, and no ansatz is smuggled via prior work. The delineation of UFO vs. non-relativistic freeze-out regions follows directly from the Boltzmann equation solutions without circular redefinition of the target observables.

Axiom & Free-Parameter Ledger

3 free parameters · 2 axioms · 0 invented entities

Only the abstract is available, so the ledger is necessarily incomplete. The model relies on standard cosmological assumptions plus model-specific parameters for masses and couplings that are scanned rather than derived.

free parameters (3)
  • mediator mass M
    Heavy scale that suppresses cross sections; scanned over values greater than or equal to 1 TeV in the abstract.
  • DM mass m_DM
    Scanned in the 0.4 GeV to 1 TeV range for viable space above neutrino fog.
  • reheating temperature
    Low value required for ultrarelativistic decoupling; not numerically specified in abstract.
axioms (2)
  • standard math Standard Model bath and thermal history during reheating
    Invoked to define relativistic decoupling and freeze-out.
  • domain assumption Z' portal interactions with strong couplings
    Required for ultrarelativistic decoupling to be generic.

pith-pipeline@v0.9.0 · 5596 in / 1557 out tokens · 49836 ms · 2026-05-08T17:50:15.218165+00:00 · methodology

discussion (0)

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

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

What do these tags mean?
matches
The paper's claim is directly supported by a theorem in the formal canon.
supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses
The paper appears to rely on the theorem as machinery.
contradicts
The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

71 extracted references · 71 canonical work pages · 2 internal anchors

  1. [1]

    Zwicky, Helv

    F. Zwicky, Helv. Phys. Acta6, 110-127 (1933)

    work page 1933

  2. [2]

    Goldberg, Phys

    H. Goldberg, Phys. Rev. Lett.50(1983) 1419

    work page 1983

  3. [3]

    Ellis, J

    J. Ellis, J. Hagelin, D. Nanopoulos, K. Olive and M. Srednicki, Nucl. Phys. B238(1984) 453

    work page 1984

  4. [4]

    D. N. Schramm and G. Steigman, Astrophys. J.243, 1 (1981)

    work page 1981

  5. [5]

    J. E. Gunn, B. W. Lee, I. Lerche, D. N. Schramm and G. Steigman, Astrophys. J.223, 1015-1031 (1978)

    work page 1978

  6. [6]

    Silveira and A

    V. Silveira and A. Zee, Phys. Lett. B161, 136 (1985)

    work page 1985

  7. [7]

    Gauge Singlet Scalars as Cold Dark Matter

    J. McDonald, Phys. Rev. D50, 3637 (1994) [hep-ph/0702143]

    work page Pith review arXiv 1994

  8. [8]

    C. P. Burgess, M. Pospelov and T. ter Veldhuis, Nucl. Phys. B619, 709 (2001) [hep-ph/0011335]

    work page Pith review arXiv 2001

  9. [9]

    Davoudiasl, R

    H. Davoudiasl, R. Kitano, T. Li and H. Murayama, Phys. Lett. B609, 117 (2005) [hep-ph/0405097]

    work page arXiv 2005

  10. [10]

    Minimal Dark Matter

    M. Cirelli, N. Fornengo and A. Strumia, Nucl. Phys. B753, 178-194 (2006) [arXiv:hep-ph/0512090 [hep-ph]]

    work page Pith review arXiv 2006

  11. [11]

    J. R. Bond and A. S. Szalay, Astrophys. J.274, 443-468 (1983) – 25 –

    work page 1983

  12. [12]

    J. R. Bond, G. Efstathiou and J. Silk,Phys. Lett.45(1980) 1980; Ya. B. Zeldovich and R. A.Sunyaev,Sov. Ast. Lett.6(1980) 457

    work page 1980

  13. [13]

    S. D. M. White, C. S. Frenk and M. Davis,Ap. J.274(1983) 61

    work page 1983

  14. [14]

    Planck 2018 results. VI. Cosmological parameters

    N. Aghanimet al.[Planck], Astron. Astrophys.641, A6 (2020) [erratum: Astron. Astrophys. 652, C4 (2021)] [arXiv:1807.06209 [astro-ph.CO]]

    work page internal anchor Pith review arXiv 2020

  15. [15]

    Brieden, H

    S. Brieden, H. Gil-Marín and L. Verde, JCAP08, no.08, 024 (2022) [arXiv:2204.11868 [astro-ph.CO]]; D. Wang, O. Mena, E. Di Valentino and S. Gariazzo, Phys. Rev. D110, no.10, 103536 (2024) [arXiv:2405.03368 [astro-ph.CO]]

    work page arXiv 2022

  16. [16]

    S. S. Gershtein and Y. B. Zeldovich, JETP Lett.4(1966), 120-122

    work page 1966

  17. [17]

    Cowsik and J

    R. Cowsik and J. McClelland, Phys. Rev. Lett.29(1972), 669-670

    work page 1972

  18. [18]

    A. S. Szalay and G. Marx, Acta Physica Acad. Sci. Hung.35, no.1-4, 113-129 (1974)

    work page 1974

  19. [19]

    Hut,Phys

    P. Hut,Phys. Lett.B69, 85, 1977; Benjamin W. Lee and Steven Weinberg,Phys. Rev. Lett.39, 165, 1977; M. I. Vysotsky, A. D. Dolgov and Ya. B. Zeldovich,JETP Lett.26, 188, 1977; E. W. Kolb and K. A. Olive, Phys. Rev. D33, 1202 (1986) [erratum: Phys. Rev. D34, 2531 (1986)]

    work page 1977

  20. [20]

    Photon Events with Missing Energy in e+e- Collisions at sqrt{s} = 130 to 209 GeV

    J. Abdallahet al.[DELPHI], Eur. Phys. J. C38, 395-411 (2005) [arXiv:hep-ex/0406019 [hep-ex]]

    work page Pith review arXiv 2005

  21. [21]

    Janot and S

    P. Janot and S. Jadach, Phys. Lett. B803, 135319 (2020) [arXiv:1912.02067 [hep-ph]]

    work page arXiv 2020

  22. [22]

    Aprile et al.,WIMP Dark Matter Search Using a 3.1 Tonne-Year Exposure of the XENONnT Experiment, Phys

    E. Aprileet al.[XENON], Phys. Rev. Lett.135, no.22, 221003 (2025) [arXiv:2502.18005 [hep-ex]]

    work page arXiv 2025

  23. [23]

    Dark Matter Search Results from 1.54 Tonne·Year Exposure of PandaX-4T,

    Z. Boet al.[PandaX], Phys. Rev. Lett.134, no.1, 011805 (2025) [arXiv:2408.00664 [hep-ex]]

    work page arXiv 2025

  24. [24]

    Dark Matter Search Results from 4.2 Tonne-Years of Exposure of the LUX-ZEPLIN (LZ) Experiment

    J. Aalberset al.[LZ], Phys. Rev. Lett.135, no.1, 011802 (2025) [arXiv:2410.17036 [hep-ex]]

    work page internal anchor Pith review arXiv 2025

  25. [25]

    D. S. Akeribet al.[LZ], [arXiv:2512.08065 [hep-ex]]

    work page arXiv

  26. [26]

    D. V. Nanopoulos, K. A. Olive and M. Srednicki, Phys. Lett. B127, 30 (1983); M. Y. Khlopov and A. D. Linde, Phys. Lett. B138, 265 (1984)

    work page 1983

  27. [27]

    L. J. Hall, K. Jedamzik, J. March-Russell and S. M. West, JHEP1003(2010) 080 [arXiv:0911.1120 [hep-ph]]; X. Chu, T. Hambye and M. H. G. Tytgat, JCAP1205(2012) 034 [arXiv:1112.0493 [hep-ph]]; A. Biswas, D. Borah and A. Dasgupta, Phys. Rev. D99, no.1, 015033 (2019) [arXiv:1805.06903 [hep-ph]]

    work page Pith review arXiv 2010

  28. [28]

    The Dawn of FIMP Dark Matter: A Review of Models and Constraints

    N. Bernal, M. Heikinheimo, T. Tenkanen, K. Tuominen and V. Vaskonen, Int. J. Mod. Phys. A 32(2017) no.27, 1730023 [arXiv:1706.07442 [hep-ph]]

    work page Pith review arXiv 2017

  29. [29]

    Mambrini, K

    Y. Mambrini, K. A. Olive, J. Quevillon and B. Zaldivar, Phys. Rev. Lett.110, no.24, 241306 (2013) [arXiv:1302.4438 [hep-ph]]

    work page arXiv 2013

  30. [30]

    Mambrini, N

    Y. Mambrini, N. Nagata, K. A. Olive, J. Quevillon and J. Zheng, Phys. Rev. D91, no.9, 095010 (2015) [arXiv:1502.06929 [hep-ph]]

    work page arXiv 2015

  31. [31]

    Cosme, F

    C. Cosme, F. Costa and O. Lebedev, Phys. Rev. D109(2024) no.7, 075038 [arXiv:2306.13061 [hep-ph]]

    work page arXiv 2024

  32. [32]

    Arcadi, D

    G. Arcadi, D. Cabo-Almeida and O. Lebedev, Phys. Lett. B861, 139268 (2025) [arXiv:2409.02191 [hep-ph]]

    work page arXiv 2025

  33. [33]

    UltraViolet Freeze-in

    F. Elahi, C. Kolda and J. Unwin, JHEP03, 048 (2015) [arXiv:1410.6157 [hep-ph]]

    work page Pith review arXiv 2015

  34. [34]

    Bernal et al.,Ultraviolet Freeze-in and Non-Standard Cosmologies,JCAP11(2019) 026 [1909.07992]

    N. Bernal, F. Elahi, C. Maldonado and J. Unwin, JCAP11, 026 (2019) [arXiv:1909.07992 [hep-ph]]

    work page arXiv 2019

  35. [35]

    Bernal, S

    N. Bernal, S. Mukherjee and J. Unwin, JCAP02, 010 (2026) [arXiv:2510.01311 [hep-ph]]. – 26 –

    work page arXiv 2026

  36. [36]

    Mambrini and K.A

    Y. Mambrini and K. A. Olive, Phys. Rev. D103(2021) no.11, 115009 [arXiv:2102.06214 [hep-ph]]

    work page arXiv 2021

  37. [37]

    Clery, Y

    S. Clery, Y. Mambrini, K. A. Olive and S. Verner, Phys. Rev. D105(2022) no.7, 075005 [arXiv:2112.15214 [hep-ph]]

    work page arXiv 2022

  38. [38]

    Cosme and T

    C. Cosme and T. Tenkanen, Phys. Rev. D102, no.12, 123534 (2020) [arXiv:2009.01149 [astro-ph.CO]]

    work page arXiv 2020

  39. [39]

    M. A. G. Garcia, W. Ke, Y. Mambrini, K. A. Olive and S. Verner, JCAP08, 039 (2025) [arXiv:2502.20471 [hep-ph]]

    work page arXiv 2025

  40. [40]

    S. E. Henrich, Y. Mambrini and K. A. Olive, Phys. Rev. D111, no.8, 083501 (2025) [arXiv:2412.13288 [hep-ph]]

    work page arXiv 2025

  41. [41]

    S. E. Henrich, Y. Mambrini and K. A. Olive, Phys. Rev. Lett.135, no.22, 221002 (2025) [arXiv:2511.02117 [hep-ph]]

    work page arXiv 2025

  42. [42]

    S. E. Henrich, M. Gross, Y. Mambrini and K. A. Olive, Phys. Rev. D112, no.10, 103538 (2025) [arXiv:2505.04703 [hep-ph]]

    work page arXiv 2025

  43. [43]

    Hambye and L

    T. Hambye and L. Vanderheyden, JCAP05, 001 (2020) [arXiv:1912.11708 [hep-ph]]

    work page arXiv 2020

  44. [44]

    Hambye, M

    T. Hambye, M. Lucca and L. Vanderheyden, Phys. Lett. B807, 135553 (2020) [arXiv:2003.04936 [hep-ph]]

    work page arXiv 2020

  45. [45]

    R. Coy, T. Hambye, M. H. G. Tytgat and L. Vanderheyden, Phys. Rev. D104, no.5, 055021 (2021) [arXiv:2105.01263 [hep-ph]]

    work page arXiv 2021

  46. [46]

    R. Coy, J. Kimus and M. H. G. Tytgat, JCAP02, 077 (2025) [arXiv:2405.10792 [hep-ph]]

    work page arXiv 2025

  47. [47]

    Arcadi, O

    G. Arcadi, O. Lebedev, S. Pokorski, and T. Toma. JHEP,08, 050 (2019) [arXiv:1906.07659 [hep-ph]]

    work page arXiv 2019

  48. [48]

    Lebedev and T

    O. Lebedev and T. Toma. JHEP,05108 (2023) [arXiv:2302.09515 [hep-ph]]

    work page arXiv 2023

  49. [49]

    Chakraborty, D

    A. Chakraborty, D. Maity and R. Mondal, [arXiv:2603.04155 [hep-ph]]

    work page arXiv

  50. [50]

    S. E. Henrich, Y. Mambrini and K. A. Olive, JCAP04, 068 (2026) [arXiv:2512.04229 [hep-ph]]

    work page arXiv 2026

  51. [51]

    Becker, E

    M. Becker, E. Copello, J. Harz, J. Lang and Y. Xu, JCAP01, 053 (2024) [arXiv:2306.17238 [hep-ph]]

    work page arXiv 2024

  52. [52]

    B´ elanger, N

    G. Bélanger, N. Bernal and A. Pukhov, JHEP03, 079 (2025) [arXiv:2412.12303 [hep-ph]]

    work page arXiv 2025

  53. [53]

    J. M. Zheng, Z. H. Yu, J. W. Shao, X. J. Bi, Z. Li and H. H. Zhang, Nucl. Phys. B854, 350-374 (2012) [arXiv:1012.2022 [hep-ph]]

    work page Pith review arXiv 2012

  54. [54]

    Iterative Monte Carlo analysis of spin-dependent parton distributions

    N. Satoet al.[Jefferson Lab Angular Momentum], Phys. Rev. D93, no.7, 074005 (2016) [arXiv:1601.07782 [hep-ph]]

    work page Pith review arXiv 2016

  55. [55]

    J. J. Ethier, N. Sato and W. Melnitchouk, Phys. Rev. Lett.119, no.13, 132001 (2017) [arXiv:1705.05889 [hep-ph]]

    work page Pith review arXiv 2017

  56. [56]

    Navaset al.[Particle Data Group], Phys

    S. Navaset al.[Particle Data Group], Phys. Rev. D110, no.3, 030001 (2024)

    work page 2024

  57. [57]

    Gotoet al.[Asymmetry Analysis], Phys

    Y. Gotoet al.[Asymmetry Analysis], Phys. Rev. D62, 034017 (2000) [arXiv:hep-ph/0001046 [hep-ph]]

    work page arXiv 2000

  58. [58]

    Z. H. Yu, J. M. Zheng, X. J. Bi, Z. Li, D. X. Yao and H. H. Zhang, Nucl. Phys. B860, 115-151 (2012) [arXiv:1112.6052 [hep-ph]]

    work page Pith review arXiv 2012

  59. [59]

    R. J. Scherrer and M. S. Turner, Phys. Rev. D31, 681 (1985)

    work page 1985

  60. [60]

    G. F. Giudice, E. W. Kolb and A. Riotto, Phys. Rev. D64(2001) 023508 [hep-ph/0005123]; D. J. H. Chung, E. W. Kolb and A. Riotto, Phys. Rev. D60(1999) 063504 [hep-ph/9809453]. – 27 –

    work page Pith review arXiv 2001

  61. [61]

    M. A. G. Garcia, K. Kaneta, Y. Mambrini and K. A. Olive, Phys. Rev. D101(2020) no.12, 123507 [arXiv:2004.08404 [hep-ph]

    work page arXiv 2020

  62. [62]

    M. A. G. Garcia, K. Kaneta, Y. Mambrini and K. A. Olive, JCAP04, 012 (2021) [arXiv:2012.10756 [hep-ph]]

    work page arXiv 2021

  63. [63]

    C. A. J. O’Hare, Phys. Rev. Lett.127, no.25, 251802 (2021) [arXiv:2109.03116 [hep-ph]]

    work page arXiv 2021

  64. [64]

    Mambrini, Particles in the dark Universe,Springer Ed., ISBN 978-3-030-78139-2 (2021)

    Y. Mambrini, Particles in the dark Universe,Springer Ed., ISBN 978-3-030-78139-2 (2021)

    work page 2021

  65. [65]

    Srednicki, R

    M. Srednicki, R. Watkins and K. A. Olive, Nucl. Phys. B310, 693 (1988)

    work page 1988

  66. [66]

    Agnes et al

    P. Agneset al.[DarkSide-50], Phys. Rev. D107, no.6, 6 (2023) [arXiv:2207.11966 [hep-ex]]

    work page arXiv 2023

  67. [67]

    Zhanget al.[PandaX], Phys

    M. Zhanget al.[PandaX], Phys. Rev. Lett.135, no.21, 211001 (2025) [erratum: Phys. Rev. Lett.136, no.6, 069901 (2026)] [arXiv:2507.11930 [hep-ex]]

    work page arXiv 2025

  68. [68]

    M. F. Albakryet al.[SuperCDMS], [arXiv:2203.08463 [physics.ins-det]]

    work page arXiv

  69. [69]

    A. M. Sirunyanet al.[CMS], JHEP07, 208 (2021) [arXiv:2103.02708 [hep-ex]]

    work page arXiv 2021

  70. [70]

    del Aguila, J

    F. del Aguila, J. de Blas and M. Perez-Victoria, JHEP09, 033 (2010) [arXiv:1005.3998 [hep-ph]]

    work page arXiv 2010

  71. [71]

    MeV-scale Reheating Temperature and Thermalization of Neutrino Background

    M. Kawasaki, K. Kohri and N. Sugiyama, Phys. Rev. D62, 023506 (2000) [arXiv:astro-ph/0002127 [astro-ph]]. P. F. de Salas, M. Lattanzi, G. Mangano, G. Miele, S. Pastor and O. Pisanti, Phys. Rev. D92, no.12, 123534 (2015) [arXiv:1511.00672 [astro-ph.CO]]. S. Hannestad, Phys. Rev. D70, 043506 (2004) [arXiv:astro-ph/0403291 [astro-ph]]; T. Hasegawa, N. Hirosh...

    work page Pith review arXiv 2000