${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit X}^{0}}{{\mathit Y}^{0}}$ , ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit Y}^{0}}{{\mathit \gamma}}$

$\text{<(0.05 - 0.8)}$

⁶

ABBIENDI

2000

OPAL

${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit X}^{0}}{{\mathit X}^{0}}$ , ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit Y}^{0}}{{\mathit \gamma}}$

$\text{<(2.5 - 0.5)}$

⁷

ACKERSTAFF

1997

OPAL

${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit X}^{0}}{{\mathit Y}^{0}}$ , ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit Y}^{0}}{{\mathit \gamma}}$

$\text{<(1.6 - 0.9)}$

⁸

ACKERSTAFF

1997

OPAL

${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit X}^{0}}{{\mathit X}^{0}}$ , ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit Y}^{0}}{{\mathit \gamma}}$

¹ ALBERT 2018C search for WIMP annihilation in Sun to long-lived, radiatively decaying mediator; no signal; limits set on $\sigma {}^{SD}$( ${{\mathit \chi}}{{\mathit p}}$ ) assuming long-lived mediator.

² KHACHATRYAN 2017D search for new scalar resonance decaying to ${{\mathit Z}}{{\mathit \gamma}}$ with ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at 8 and 13 TeV; no signal seen.

³ AAD 2016AI search for excited quarks (EQ) and quantum black holes (QBH) in 3.2 fb${}^{-1}$ at 13 TeV of data; exclude EQ below 4.4 TeV and QBH below 3.8 (6.2) TeV for RS1 (ADD) models. The visible cross section limit was obtained for 5 TeV resonance with ${{\mathit \sigma}_{{G}}}/{{\mathit M}_{{G}}}$ = 2$\%$.

⁴ KHACHATRYAN 2016M search for ${{\mathit \gamma}}{{\mathit \gamma}}$ resonance using 19.7 fb${}^{-1}$ at 8 TeV and 3.3 fb${}^{-1}$ at 13 Tev; slight excess at 750 GeV noted; limit set on RS graviton.

⁵ ABBIENDI 2000D associated production limit is for ${\mathit m}_{{{\mathit X}^{0}}}$= $90 - 188$ GeV, ${\mathit m}_{{{\mathit Y}^{0}}}$=0 at $\mathit E_{{\mathrm {cm}}}$=189 GeV. See also their Fig.$~$9.

⁶ ABBIENDI 2000D pair production limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ = $45 - 94$ GeV, ${\mathit m}_{{{\mathit Y}^{0}}}$=0 at $\mathit E_{{\mathrm {cm}}}$=189 GeV. See also their Fig.$~$12.

⁷ ACKERSTAFF 1997B associated production limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ = $80 - 160$ GeV, ${\mathit m}_{{{\mathit Y}^{0}}}$=0 from $10.0~$pb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 161 GeV. See their Fig.$~$3(a).

⁸ ACKERSTAFF 1997B pair production limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ = $40 - 80$ GeV, ${\mathit m}_{{{\mathit Y}^{0}}}$=0 from $10.0~$pb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 161 GeV. See their Fig.$~$3(b).

References:

ALBERT

2018C

PR D98 123012

Constraints on Spin-Dependent Dark Matter Scattering with Long-Lived Mediators from TeV Observations of the Sun with HAWC

KHACHATRYAN

2017D

JHEP 1701 076

Search for High-Mass ${{\mathit Z}}{{\mathit \gamma}}$ Resonances in ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \gamma}}$ and ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}}$ Final States in Proton-Proton Collisions at $\sqrt {s }$ = 8 and 13 TeV

AAD

2016AI

JHEP 1603 041

Search for New Phenomena with Photon $+$ Jet Events in Proton-Proton Collisions at $\sqrt {s }$ = 13 TeV with the ATLAS Detector

KHACHATRYAN

2016M

PRL 117 051802

Search for Resonant Production of High-Mass Photon Pairs in Proton-Proton Collisions at $\sqrt {s }$ = 8 and 13 TeV

ABBIENDI

2000D

EPJ C13 197

A Study of Three Prong ${{\mathit \tau}}$ Decays with Charged Kaons

ACKERSTAFF

1997B

PL B391 210

Photonic Events with Large Missing Energy in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at $\sqrt {s }$ = 161 GeV