Probing MeV to 90 GeV axion-like particles with LEP and LHC

By J. Jaeckel, Michael Spannowsky. 2015

314 citations recorded by the source corpus.

Abstract Axion-like particles (ALPs), relatively light (pseudo-)scalars coupled to two gauge bosons, are a common feature of many extensions of the Standard Model. Up to now there has been a gap in the sensitivity to such particles in the MeV to 10 GeV range. In this note we show that LEP data on Z → γ γ decays provides significant constraints in this range (and indeed up to the Z-mass). We also discuss the sensitivities of LHC and future colliders. Particularly the LHC shows promising sensitivity in searching for a pseudo-scalar with 4 ≲ m a ≲ 60 GeV in the channel p p → 3 γ with m 3 γ ≈ m Z .

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/aa5ca4e07bde647f6148d86ab5ebd398ce2866c4

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Citations in the corpus

Factoring the strong CP problem (2017, background): “The light blue region includes these astrophysical constraints (adapted from [64]).”
Physics beyond colliders at CERN: beyond the Standard Model working group report (2019, background): “(5) LEP: limits from LEP data in the ALP mass range MeV–GeV arise from a reinterpretation [315] of the LEP gg  Z 0 data [316–319] where one of the two neutral clusters was considered the result of a merging of two highly collimated photons from the ALP decay in the process g gg   Z a a , 0 .”
Axion-like particles at future colliders (2018, background): “We distinguish resonant production through gluon or photon fusion and e+e− annihilation, the production in association with photons, Z bosons, Higgs bosons or jets [34–37], and the production via exotic decays of on-shell Higgs or Z bosons [25, 28].”
Revised constraints and Belle II sensitivity for visible and invisible axion-like particles (2017, background): “[20], CDF constraints on Z → γγ from ref.”
ALPtraum: ALP production in proton beam dump experiments (2015, methodology): “Larger couplings, on the other hand, can be tested directly at colliders such as LEP or the LHC [11].”
Dark matter, millicharges, axion and scalar particles, gauge bosons, and other new physics with LDMX (2018, background): “Nearly all 2 viable thermal DM scenarios below the GeV-scale contain all of the following ingredients: 1) SM Neutrality: Unlike WIMPs, which can realize thermal freeze-out via SM gauge interactions, sub-GeV relics must not carry electroweak quantum numbers; new electroweak states are essentially rul”
The landscape of QCD axion models (2020, background): “These bounds are nicely complemented by constraints from beam dump and reactor experiments which exclude axion (and ALP) masses from MeV up to several GeVs [282–293].”
Collider probes of axion-like particles (2017, methodology): “Constraints on the ALP mass and coupling to photons derived from various experiments (colored areas without boundaries, adapted from [24]) along with the parameter regions that can be probed using the Higgs decays h → Za → `+`−γγ.”