ANOMALOUS ${{\boldsymbol Z}}{{\boldsymbol Z}}{{\boldsymbol \gamma}}$ , ${{\boldsymbol Z}}{{\boldsymbol \gamma}}{{\boldsymbol \gamma}}$ , AND ${{\boldsymbol Z}}{{\boldsymbol Z}}{{\boldsymbol V}}$ COUPLINGS

$\boldsymbol h{}^{\boldsymbol V}_{\boldsymbol i}$ INSPIRE search

Combining the LEP-2 results taking into account the correlations, the following 95$\%$ CL limits are derived [SCHAEL 2013A]:

$-0.12<$ $\mathit h{}^{{{\mathit Z}}}_{1}<+0.11$, $-0.07<$ $\mathit h{}^{{{\mathit Z}}}_{2}<+0.07$, $-0.19<$ $\mathit h{}^{{{\mathit Z}}}_{3}<+0.06$, $-0.04<$ $\mathit h{}^{{{\mathit Z}}}_{4}<+0.13$, $-0.05<$ $\mathit h{}^{{{\mathit \gamma}}}_{1}<+0.05$, $-0.04<$ $\mathit h{}^{{{\mathit \gamma}}}_{2}$ $<+0.02$, $-0.05<$ $\mathit h{}^{{{\mathit \gamma}}}_{3}<+0.00$, $+0.01<$ $\mathit h{}^{{{\mathit \gamma}}}_{4 }$ $<+0.05$.

Some of the recent results from the Tevatron and LHC experiments individually surpass the combined LEP-2 results in precision (see below).

VALUE DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
1
AAD
2016Q
ATLS ${\it{}E}^{\it{}pp}_{\rm{}cm}$ = 8 TeV
2
KHACHATRYAN
2016AE
CMS ${\it{}E}^{\it{}pp}_{\rm{}cm}$ = 8 TeV
3
KHACHATRYAN
2015AC
CMS ${\it{}E}^{\it{}pp}_{\rm{}cm}$ = 8 TeV
4
CHATRCHYAN
2014AB
CMS ${\it{}E}^{\it{}pp}_{\rm{}cm}$ = 7 TeV
5
AAD
2013AN
ATLS ${\it{}E}^{\it{}pp}_{\rm{}cm}$ = 7 TeV
6
CHATRCHYAN
2013BI
CMS ${\it{}E}^{\it{}pp}_{\rm{}cm}$ = 7 TeV
7
ABAZOV
2012S
D0 ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$ = 1.96 TeV
8
AALTONEN
2011S
CDF ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$ = 1.96 TeV
9
CHATRCHYAN
2011M
CMS ${\it{}E}^{\it{}pp}_{\rm{}cm}$ = 7 TeV
10
ABAZOV
2009L
D0 ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$ = 1.96 TeV
11
ABAZOV
2007M
D0 ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$ = 1.96 TeV
12
ABDALLAH
2007C
DLPH ${\it{}E}^{\it{}ee}_{\rm{}cm}$ = $183 - 208$ GeV
13
ACHARD
2004H
L3 ${\it{}E}^{\it{}ee}_{\rm{}cm}$ = $183 - 208$ GeV
14
ABBIENDI,G
2000C
OPAL ${\it{}E}^{\it{}ee}_{\rm{}cm}$ = 189 GeV
15
ABBOTT
1998M
D0 ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$ = 1.8 TeV
16
ABREU
1998K
DLPH ${\it{}E}^{\it{}ee}_{\rm{}cm}$ = 161, 172 GeV
1  AAD 2016Q study ${{\mathit Z}}{{\mathit \gamma}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions. In events with no additional jets, 10268 (12738) ${{\mathit Z}}$ decays to electron (muon) pairs are selected, with an expected background of $1291$ $\pm340$ ($1537$ $\pm408$) events, as well as 1039 ${{\mathit Z}}$ decays to neutrino pairs with an expected background of $450$ $\pm96$ events. Analyzing the photon transverse momentum distribution above 250 GeV (400 GeV) for lepton (neutrino) events, yields the 95$\%$ C.L. limits: $-7.8 \times 10^{-4}<{{\mathit h}_{{3}}^{Z}}<8.6 \times 10^{-4}$, $-3.0 \times 10^{-6}<{{\mathit h}_{{4}}^{Z}}<2.9 \times 10^{-6}$, $-9.5 \times 10^{-4}<{{\mathit h}}{}^{{{\mathit \gamma}}}_{3}<9.9 \times 10^{-4}$, $-3.2 \times 10^{-6}<{{\mathit h}}{}^{{{\mathit \gamma}}}_{4}<3.2 \times 10^{-6}$.
2  KHACHATRYAN 2016AE determine the ${{\mathit Z}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit \gamma}}$ cross section by selecting events with a photon of $\mathit E_{T}$ $>$ 145 GeV and $\not E_T$ $>$ 140 GeV. 630 candidate events are observed with an expected SM background of $269$ $\pm26$. The $\mathit E_{T}$ spectrum of the photon is used to set 95$\%$ C.L. limits as follows: $-1.5 \times 10^{-3}<{{\mathit h}_{{3}}^{Z}}<1.6 \times 10^{-3}$, $-3.9 \times 10^{-6}<{{\mathit h}_{{4}}^{Z}}<4.5 \times 10^{-6}$, $-1.1 \times 10^{-3}<{{\mathit h}}{}^{{{\mathit \gamma}}}_{3}<0.9 \times 10^{-3}$, $-3.8 \times 10^{-6}<{{\mathit h}}{}^{{{\mathit \gamma}}}_{4}<4.3 \times 10^{-6}$.
3  KHACHATRYAN 2015AC study ${{\mathit Z}}{{\mathit \gamma}}$ events in 8 TeV ${{\mathit p}}{{\mathit p}}$ interactions, where the ${{\mathit Z}}$ decays into 2 same-flavor, opposite sign leptons (${{\mathit e}}$ or ${{\mathit \mu}}$) and a photon with $p_T$ $>$ 15 GeV. The $p_T$ of a lepton is required to be $>$ 20 GeV/c, their effective mass $>$ 50 GeV, and the photon should have a separation $\Delta $R $>$ 0.7 with each lepton. The observed $p_T$ distribution of the photons is used to extract the 95$\%$ C.L. limits: $-3.8 \times 10^{-3}$ $<$ $\mathit h{}^{{{\mathit Z}}}_{3}$ $<$ $3.7 \times 10^{-3}$, $-3.1 \times 10^{-5}$ $<$ $\mathit h{}^{{{\mathit Z}}}_{4}$ $<$ $3.0 \times 10^{-5}$, $-4.6 \times 10^{-3}$ $<$ $\mathit h{}^{{{\mathit \gamma}}}_{3}$ $<$ $4.6 \times 10^{-3}$, $-3.6 \times 10^{-5}$ $<$ $\mathit h{}^{{{\mathit \gamma}}}_{4}$ $<$ $3.5 \times 10^{-5}$.
4  CHATRCHYAN 2014AB measure ${{\mathit Z}}{{\mathit \gamma}}$ production cross section for p${}^{\gamma }_{T}$ $>$ 15 GeV and R( ${{\mathit \ell}}{{\mathit \gamma}}$ ) $>$ 0.7, which is the separation between the ${{\mathit \gamma}}$ and the final state charged lepton (${{\mathit e}}$ or ${{\mathit \mu}}$) in the azimuthal angle-pseudorapidity (${{\mathit \phi}}−{{\mathit \eta}}$) plane. The di-lepton mass is required to be $>$ 50 GeV. After background subtraction the number of ${{\mathit e}}{{\mathit e}}{{\mathit \gamma}}$ and ${{\mathit \mu}}{{\mathit \mu}}{{\mathit \gamma}}$ events is determined to be $3160$ $\pm120$ and $5030$ $\pm233$ respectively, compatible with expectations from the SM. This leads to a 95$\%$ CL limits of $-0.01$ $<$ ${{\mathit h}}{}^{{{\mathit \gamma}}}_{3}$ $<$ $0.01$, $-9 \times 10^{-5}$ $<$ ${{\mathit h}}{}^{{{\mathit \gamma}}}_{4}$ $<$ $9 \times 10^{-5}$, $-9 \times 10^{-3}$ $<$ ${{\mathit h}_{{3}}^{Z}}$ $<$ $9 \times 10^{-3}$, $-8 \times 10^{-5}$ $<$ ${{\mathit h}_{{4}}^{Z}}$ $<$ $8 \times 10^{-5}$, assuming ${{\mathit h}_{{1}}^{V}}$ and ${{\mathit h}_{{2}}^{V}}$ have SM values, ${{\mathit V}}$ = ${{\mathit \gamma}}$ or ${{\mathit Z}}$.
5  AAD 2013AN study ${{\mathit Z}}{{\mathit \gamma}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions. In events with no additional jet, 1417 (2031) Z decays to electron (muon) pairs are selected, with an expected background of $156$ $\pm54$ ($244$ $\pm64$) events, as well as 662 ${{\mathit Z}}$ decays to neutrino pairs with an expected background of $302$ $\pm42$ events. Analysing the photon $p_T$ spectrum above 100 GeV yields the 95$\%$ C.L. limts: $-0.013$ $<$ ${{\mathit h}_{{3}}^{Z}}$ $<$ 0.014, $-8.7 \times 10^{-5}$ $<$ ${{\mathit h}_{{4}}^{Z}}$ $<$ $8.7 \times 10^{-5}$, $-0.015$ $<$ $\mathit h{}^{{{\mathit \gamma}}}_{3}$ $<$ 0.016, $-9.4 \times 10^{-5}$ $<$ $\mathit h{}^{{{\mathit \gamma}}}_{4}$ $<$ $9.2 \times 10^{-5}$. Supersedes AAD 2012BX.
6  CHATRCHYAN 2013BI determine the ${{\mathit Z}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit \gamma}}$ cross section by selecting events with a photon of $\mathit E_{T}>$ 145 GeV and a $\not E_T>$ 130 GeV. 73 candidate events are observed with an expected SM background of $30.2$ $\pm6.5$. The $\mathit E_{T}$ spectrum of the photon is used to set 95$\%$ C.L. limits as follows: $\vert {{\mathit h}_{{3}}^{Z}}\vert <$ $2.7 \times 10^{-3}$, $\vert {{\mathit h}_{{4}}^{Z}}\vert <$ $1.3 \times 10^{-5}$, $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{3}\vert <$ $2.9 \times 10^{-3}$, $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{4}\vert <$ $1.5 \times 10^{-5}$.
7  ABAZOV 2012S study ${{\mathit Z}}{{\mathit \gamma}}$ production in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV using 6.2 fb${}^{-1}$ of data where the ${{\mathit Z}}$ decays to electron (muon) pairs and the photon has at least 10 GeV of transverse momentum. In data, 304 (308) di-electron (di-muon) events are observed with an expected background of $255$ $\pm16$ ($285$ $\pm24$) events. Based on the photon $p_T$ spectrum, and including also earlier data and the ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ decay mode (from ABAZOV 2009L), the following 95$\%$ C.L. limits are reported: $\vert {{\mathit h}_{{03}}^{Z}}\vert $ $<$ 0.026, $\vert {{\mathit h}_{{04}}^{Z}}\vert $ $<$ 0.0013, $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{03}\vert $ $<$ 0.027, $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{04}\vert $ $<$ 0.0014 for a form factor scale of $\Lambda $ = 1.5 TeV.
8  AALTONEN 2011S study ${{\mathit Z}}{{\mathit \gamma}}$ events in ${{\mathit p}}{{\overline{\mathit p}}}$ interactions at $\sqrt {s }$ = 1.96 TeV with integrated luminosity 5.1 fb${}^{-1}$ for ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ /${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ and 4.9 fb${}^{-1}$ for ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ . For the charged lepton case, the two leptons must be of the same flavor with the transverse momentum/energy of one $>$ 20 GeV and the other $>$ 10 GeV. The isolated photon must have $\mathit E_{T}>$ 50 GeV. They observe 91 events with $87.2$ $\pm7.8$ events expected from standard model processes. For the ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ case they require solitary photons with $\mathit E_{T}>$ 25 GeV and missing $\mathit E_{T}$ $>$ 25 GeV and observe 85 events with standard model expectation of $85.9$ $\pm5.6$ events. Taking the form factor $\Lambda $ = 1.5 TeV they derive 95$\%$ C.L. limits as $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{3}{}^{,Z}\vert $ $<$ 0.022 and $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{4}{}^{,Z}\vert $ $<$ 0.0009.
9  CHATRCHYAN 2011M study ${{\mathit Z}}{{\mathit \gamma}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV using 36 pb${}^{-1}$ ${{\mathit p}}{{\mathit p}}$ data, where the ${{\mathit Z}}$ decays to ${{\mathit e}^{+}}{{\mathit e}^{-}}$ or ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ . The total cross sections are measured for photon transverse energy ${{\mathit E}}{}^{{{\mathit \gamma}}}_{T}>$ 10 GeV and spatial separation from charged leptons in the plane of pseudo rapidity and azimuthal angle $\Delta {{\mathit R}}({{\mathit \ell}},{{\mathit \gamma}})>$ 0.7 with the dilepton invariant mass requirement of ${{\mathit M}}_{ {{\mathit \ell}} {{\mathit \ell}} }>$ 50 GeV. The number of ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \gamma}}$ and ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}}$ candidates is 81 and 90 with estimated backgrounds of $20.5$ $\pm2.5$ and $27.3$ $\pm3.2$ events respectively. The 95$\%$ CL limits for ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ couplings are $-0.05<$ ${{\mathit h}_{{3}}^{Z}}<$ 0.06 and $-0.0005<{{\mathit h}_{{4}}^{Z}}<$ 0.0005, and for ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ couplings are $-0.07<{{\mathit h}}{}^{{{\mathit \gamma}}}_{3}<$ 0.07 and $-0.0005<{{\mathit h}}{}^{{{\mathit \gamma}}}_{4}<$ 0.0006.
10  ABAZOV 2009L study ${{\mathit Z}}{{\mathit \gamma}}$ , ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ production in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at 1.96 TeV C.M. energy. They select 51 events with a photon of transverse energy $\mathit E_{T}$ larger than 90 GeV, with an expected background of 17 events. Based on the photon $\mathit E_{T}$ spectrum and including also ${{\mathit Z}}$ decays to charged leptons (from ABAZOV 2007M), the following 95$\%$ CL limits are reported: $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{30}\vert <$ 0.033, $\vert {{\mathit h}}{}^{{{\mathit \gamma}}}_{40}\vert <$ 0.0017, $\vert {{\mathit h}_{{30}}^{Z}}\vert <$ 0.033, $\vert {{\mathit h}_{{40}}^{Z}}\vert <$ 0.0017.
11  ABAZOV 2007M use 968 ${{\mathit p}}$ ${{\overline{\mathit p}}}$ ${{\mathit e}^{-}}$ $/$ ${{\mathit \mu}^{+}}$ ${{\mathit \mu}^{-}}$ ${{\mathit \gamma}}$ ${{\mathit X}}$ candidates, at 1.96 TeV center of mass energy, to tag ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$ events by requiring $\mathit E_{T}({{\mathit \gamma}})>$ 7 GeV, lepton-gamma separation $\Delta R_{ {{\mathit \ell}} {{\mathit \gamma}} }>$ 0.7, and di-lepton invariant mass $>$ 30 GeV. The cross section is in agreement with the SM prediction. Using these ${{\mathit Z}}{{\mathit \gamma}}$ events they obtain 95$\%$ C.L. limits on each ${{\mathit h}_{{i}}^{V}}$, keeping all others fixed at their SM values. They report: $-0.083<{{\mathit h}_{{30}}^{Z}}<$ 0.082, $-0.0053<{{\mathit h}_{{40}}^{Z}}<$ 0.0054, $-0.085<{{\mathit h}}{}^{{{\mathit \gamma}}}_{30}<$ 0.084, $-0.0053<{{\mathit h}}{}^{{{\mathit \gamma}}}_{40}<$ 0.0054, for the form factor scale $\Lambda $= 1.2 TeV.
12  Using data collected at $\sqrt {s }$ = $183 - 208$, ABDALLAH 2007C select 1,877 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$ events with ${{\mathit Z}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ or ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ , 171 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit Z}}$ events with ${{\mathit Z}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ or lepton pair (except an explicit ${{\mathit \tau}}$ pair), and 74 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}^{*}}$ events with a ${{\mathit q}}{{\overline{\mathit q}}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ or ${{\mathit q}}{{\overline{\mathit q}}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ signature, to derive 95$\%$ CL limits on ${{\mathit h}_{{i}}^{V}}$. Each limit is derived with other parameters set to zero. They report: $-0.23<{{\mathit h}_{{1}}^{Z}}<$ 0.23, $-0.30<{{\mathit h}_{{3}}^{Z}}<$ 0.16, $-0.14<{{\mathit h}}{}^{{{\mathit \gamma}}}_{1}<$ 0.14, $-0.049<{{\mathit h}}{}^{{{\mathit \gamma}}}_{3}<$ 0.044.
13  ACHARD 2004H select 3515 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$ events with ${{\mathit Z}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ or ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ at $\sqrt {s }$ = $189 - 209$ GeV to derive 95$\%$ CL limits on ${{\mathit h}^{V}_{{i}}}$. For deriving each limit the other parameters are fixed at zero. They report: $-0.153<{{\mathit h}_{{1}}^{Z}}<0.141$, $-0.087<{{\mathit h}_{{2}}^{Z}}<0.079$, $-0.220<{{\mathit h}_{{3}}^{Z}}<0.112$, $-0.068<{{\mathit h}_{{4}}^{Z}}<0.148$, $-0.057<{{\mathit h}}{}^{{{\mathit \gamma}}}_{1}<0.057$, $-0.050<{{\mathit h}}{}^{{{\mathit \gamma}}}_{2}<0.023$, $-0.059<{{\mathit h}}{}^{{{\mathit \gamma}}}_{3}<0.004$, $-0.004<{{\mathit h}}{}^{{{\mathit \gamma}}}_{4}<0.042$.
14  ABBIENDI,G 2000C study ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$ events (with ${{\mathit Z}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ and ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ ) at 189 GeV to obtain the central values (and 95$\%$ CL limits) of these couplings: $\mathit h{}^{{{\mathit Z}}}_{1}$= $0.000$ $\pm0.100$ ($-0.190,~0.190$), $\mathit h{}^{{{\mathit Z}}}_{2}$= $0.000$ $\pm0.068$ ($-0.128,~0.128$), $\mathit h{}^{{{\mathit Z}}}_{3}$= $-0.074$ ${}^{+0.102}_{-0.103}$ ($-0.269,~0.119$), $\mathit h{}^{{{\mathit Z}}}_{4}$= $0.046$ $\pm0.068$ ($-0.084,~0.175$), $\mathit h{}^{{{\mathit \gamma}}}_{1}$= $0.000$ $\pm0.061$ ($-0.115,~0.115$), $\mathit h{}^{{{\mathit \gamma}}}_{2}$= $0.000$ $\pm0.041$ ($-0.077,~0.077$), $\mathit h{}^{{{\mathit \gamma}}}_{3}$= $-0.080$ ${}^{+0.039}_{-0.041}$ ($-0.164,~-0.006$), $\mathit h{}^{{{\mathit \gamma}}}_{4}$= $0.064$ ${}^{+0.033}_{-0.030}$ ($+0.007,~+0.134$). The results are derived assuming that only one coupling at a time is different from zero.
15  ABBOTT 1998M study ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$ $+$ X, with ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , ${{\overline{\mathit \nu}}}{{\mathit \nu}}$ at $1.8$ TeV, to obtain 95$\%$ CL limits at $\Lambda $= 750 GeV: $\vert \mathit h{}^{{{\mathit Z}}}_{30}\vert <0.36$, $\vert \mathit h{}^{{{\mathit Z}}}_{40}\vert <0.05$ (keeping $\mathit h{}^{{{\mathit \gamma}}}_{i}$=0), and $\vert \mathit h{}^{{{\mathit \gamma}}}_{30}\vert <0.37$, $\vert \mathit h{}^{{{\mathit \gamma}}}_{40}\vert <0.05$ (keeping $\mathit h{}^{{{\mathit Z}}}_{\mathit i}$=0). Limits on the $\mathit CP$-violating couplings are $\vert \mathit h{}^{{{\mathit Z}}}_{10}\vert <0.36$, $\vert \mathit h{}^{{{\mathit Z}}}_{20}\vert <0.05$ (keeping $\mathit h{}^{{{\mathit \gamma}}}_{\mathit i}$=0), and $\vert \mathit h{}^{{{\mathit \gamma}}}_{10}\vert <0.37$, $\vert \mathit h{}^{{{\mathit \gamma}}}_{20}\vert <0.05$ (keeping $\mathit h{}^{{{\mathit Z}}}_{\mathit i}$=0).
16  ABREU 1998K determine a 95$\%$ CL upper limit on ${\mathit \sigma (}$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}$ $+$ invisible particles${)}$ $<2.5~$pb using 161 and 172 GeV data. This is used to set 95$\%$ CL limits on $\vert \mathit h{}^{{{\mathit \gamma}}}_{30}\vert <0.8$ and $\vert \mathit h{}^{{{\mathit Z}}}_{30}\vert <1.3$, derived at a scale $\Lambda =1~$TeV and with $\mathit n$=3 in the form factor representation.
  References:
AAD 2016Q
PR D93 112002 Measurements of ${{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ Production in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 8 TeV with the ATLAS Detector
KHACHATRYAN 2016AE
PL B760 448 Measurement of the ${{\mathit Z}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit \gamma}}$ Production Cross Section in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 8 TeV and Limits on Anomalous ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ Trilinear Gauge Boson Couplings
KHACHATRYAN 2015AC
JHEP 1504 164 Measurement of the ${{\mathit Z}}{{\mathit \gamma}}$ Production Cross Section in ${{\mathit p}}{{\mathit p}}$ Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings
CHATRCHYAN 2014AB
PR D89 092005 Measurement of the ${{\mathit W}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}$ Inclusive Cross Sections in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV and Limits on Anomalous Triple Gauge Boson Couplings
AAD 2013AN
PR D87 112003 Measurements of ${{\mathit W}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}$ Production in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV with the ATLAS Detector at the LHC
CHATRCHYAN 2013BI
JHEP 1310 164 Measurement of the Production Cross Section for ${{\mathit Z}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit \gamma}}$ in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV and Limits on ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ Triple Gauge Boson Couplings
ABAZOV 2012S
PR D85 052001 ${{\mathit Z}}{{\mathit \gamma}}$ Production and Limits on Anomalous ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ Couplings in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96 TeV
AALTONEN 2011S
PRL 107 051802 Limits on Anomalous Trilinear Gauge Couplings in ${{\mathit Z}}{{\mathit \gamma}}$ Events from ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96 TeV
CHATRCHYAN 2011M
PL B701 535 Measurement of ${{\mathit W}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}$ Production in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV
ABAZOV 2009L
PRL 102 201802 Measurement of the ${{\mathit Z}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit \gamma}}$ Production Cross Section and Limits on Anomalous ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ Couplings in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96$~$TeV
ABAZOV 2007M
PL B653 378 ${{\mathit Z}}{{\mathit \gamma}}$ Production and Limits on Anomalous ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ Couplings in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96 TeV
ABDALLAH 2007C
EPJ C51 525 Study of Triple-Gauge-Boson Couplings ${{\mathit Z}}{{\mathit Z}}{{\mathit Z}}$ , ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ at LEP
ACHARD 2004H
PL B597 119 Study of the ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$ Process at LEP and Limits on Triple Neutral Gauge Boson Couplings
ABBIENDI,G 2000C
EPJ C17 553 Search for Trilinear Neutral Gauge Boson Couplings in ${{\mathit Z}}{{\mathit \gamma}}$ Production at $\sqrt {s }$ = 189 GeV at LEP
ABBOTT 1998M
PR D57 3817 ${{\mathit Z}}{{\mathit \gamma}}$ Production in ${{\overline{\mathit p}}}{{\mathit p}}$ Collisions $\sqrt {s }$ = 1.8 TeV and Limits on Anomalous ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ and ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ Couplings
ABREU 1998K
PL B423 194 Measurement of Trilinear Gauge Couplings in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at 161 and 172 GeV