# ${{\boldsymbol H}^{0}}{{\boldsymbol H}^{0}}$ Production INSPIRE search

The 95$\%$ CL limits are for the cross section (CS) and Higgs self coupling (${{\mathit \kappa}_{{\lambda}}}$) scaling factors both relative to the SM predictions.
CS ${{\mathit \kappa}_{{\lambda}}}$ CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<6.9$ $-5.0$ to 12.0 95 1
 2020 C
ATLS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \gamma}}{{\mathit \gamma}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit W}}{{\mathit W}^{*}}$ , ${{\mathit W}}{{\mathit W}^{*}}{{\mathit \gamma}}{{\mathit \gamma}}$ , ${{\mathit W}}{{\mathit W}^{*}}{{\mathit W}}{{\mathit W}^{*}}$
$<40$ 95 2
 2020 E
ATLS 13 TeV, ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$
$<12.9$ 95 3
 2019 A
ATLS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$
$<300$ 95 4
 2019 O
ATLS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit W}}{{\mathit W}^{*}}$
$<160$ 95 5
 2019 T
ATLS 13 TeV, ${{\mathit W}}{{\mathit W}^{*}}{{\mathit W}}{{\mathit W}^{*}}$
$<24$ $-11$ to 17 95 6
 2019
CMS 13 TeV, ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$
$<75$ 95 7
 2019 AB
CMS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$
$<22.2$ $-11.8$ to 18.8 95 8
 2019 BE
CMS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \gamma}}{{\mathit \gamma}}$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit W}}{{\mathit W}^{*}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit Z}}{{\mathit Z}^{*}}$
$<179$ 95 9
 2019 H
CMS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$
$<230$ 95 10
 2018 BU
ATLS 13 TeV, ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit W}}{{\mathit W}^{*}}$
$<12.7$ 95 11
 2018 CQ
ATLS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$
$<22$ $-8.2$ to 13.2 95 12
 2018 CW
ATLS 13 TeV, ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$
$<30$ 95 13
 2018 A
CMS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$
$<79$ 95 14
 2018 F
CMS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$
$<43$ 95 15
 2017 CN
CMS 8 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ , ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$
$<108$ 95 16
 2016 I
ATLS 13 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$
$<74$ 95 17
 2016 BQ
CMS 8 TeV, ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$
$<70$ 95 18
 2015 CE
ATLS 8 TeV, ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ , ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit W}}{{\mathit W}}$
1  AAD 2020C combine results of up to 36.1 fb${}^{-1}$ data at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV for ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \gamma}}{{\mathit \gamma}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit W}}{{\mathit W}^{*}}$ , ${{\mathit W}}{{\mathit W}^{*}}{{\mathit \gamma}}{{\mathit \gamma}}$ , ${{\mathit W}}{{\mathit W}^{*}}{{\mathit W}}{{\mathit W}^{*}}$ (AABOUD 2018CW, AABOUD 2018CQ, AABOUD 2019A, AABOUD 2019O, AABOUD 2018BU, and AABOUD 2019T).
2  AAD 2020E search non-resonant for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$ , where one of the Higgs bosons decays to ${{\mathit b}}{{\overline{\mathit b}}}$ and the other decays to either ${{\mathit W}}{{\mathit W}^{*}}$ , ${{\mathit Z}}{{\mathit Z}^{*}}$ , or ${{\mathit \tau}}{{\mathit \tau}}$ , with data of 139 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section at 95$\%$ CL is measured to be 1.2 pb, which corresponds to about 40 times the SM prediction.
3  AABOUD 2019A search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ with data of 36.1 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ production cross section at 95$\%$ is measured to be 147 fb, which corresponds to about 12.9 times the SM prediction.
4  AABOUD 2019O search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit W}}{{\mathit W}^{*}}$ with data of 36.1 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section at 95$\%$ CL is calculated to be 10 pb from the observed upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit W}}{{\mathit W}^{*}}$ production cross section of 2.5 pb assuming the SM branching fractions. The former corresponds to about 300 times the SM prediction.
5  AABOUD 2019T search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit W}}{{\mathit W}^{*}}{{\mathit W}}{{\mathit W}^{*}}$ with data of 36.1 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section at 95$\%$ is measured to be 5.3 pb, which corresponds to about 160 times the SM prediction.
6  SIRUNYAN 2019 search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ with data of 35.9 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ production cross section at 95$\%$ CL is measured to be 2.0 fb, which corresponds to about 24 times the SM prediction. The effective Higgs boson self-coupling $\kappa _{\lambda }$ ( = $\lambda _{ {{\mathit H}} {{\mathit H}} {{\mathit H}} }$ $/$ $\lambda {}^{SM}_{ {{\mathit H}} {{\mathit H}} {{\mathit H}} }$) is constrainted to be $-11$ $<$ $\kappa _{\lambda }$ $<$ $17$ at 95$\%$ CL assuming all other Higgs boson couplings are at their SM value.
7  SIRUNYAN 2019AB search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , where 4 heavy flavor jets from two Higgs bosons are resolved, with data of 35.9 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ production cross section at 95$\%$ is measured to be 847 fb, which corresponds to about 75 times the SM prediction.
8  SIRUNYAN 2019BE combine results of 13 TeV 35.9 fb${}^{-1}$ data: SIRUNYAN 2019 , SIRUNYAN 2018A, SIRUNYAN 2019AB, SIRUNYAN 2019H, and SIRUNYAN 2018F.
9  SIRUNYAN 2019H search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , where one of ${{\mathit b}}{{\overline{\mathit b}}}$ pairs is highly boosted and the other one is resolved, with data of 35.9 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ production cross section at 95$\%$ is measured to be 1980 fb, which corresponds to about 179 times the SM prediction.
10  AABOUD 2018BU search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit W}}{{\mathit W}^{*}}$ with the final state of ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit j}}{{\mathit j}}$ using data of 36.1 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section at 95$\%$ CL is measured to be 7.7 pb, which corresponds to about 230 times the SM prediction. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit W}}{{\mathit W}^{*}}$ at 95$\%$ CL is measured to be 7.5 fb (see thier Table 6).
11  AABOUD 2018CQ search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ with data of 36.1 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ production cross section at 95$\%$ is measured to be 30.9 fb, which corresponds to about 12.7 times the SM prediction.
12  AABOUD 2018CW search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ with data of 36.1 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section at 95$\%$ is measured to be 0.73 pb, which corresponds to about 22 times the SM prediction. The effective Higgs boson self-coupling $\kappa _{\lambda }$ is constrained to be $-8.2$ $<$ $\kappa _{\lambda }$ $<$ $13.2$ at 95$\%$ CL assuming all other Higgs boson couplings are at their SM value.
13  SIRUNYAN 2018A search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ with data of 35.9 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ production cross section is measured to be 75.4 fb, which corresponds to about 30 times the SM prediction. Limits on Higgs-boson trilinear coupling ${{\mathit \lambda}_{{HHH}}}$ and top Yukawa coupling ${{\mathit y}_{{t}}}$ are also given (see their Fig. 6).
14  SIRUNYAN 2018F search non-resonant for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$ , where ${{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$ is either ${{\mathit W}}$ ${{\mathit W}}$ $\rightarrow$ ${{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$ or ${{\mathit Z}}$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \ell}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit \nu}}$ (${{\mathit \ell}}$ is ${{\mathit e}}$ , ${{\mathit \mu}}$ or a leptonically decaying ${{\mathit \tau}}$), with data of 35.9 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$ production cross section at 95$\%$ CL is measured to be 72 fb, which corresponds to about 79 times the SM prediction.
15  SIRUNYAN 2017CN search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ with data of 18.3 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. Results are then combined with the published results of the ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ and ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , which use data of up to 19.7 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. The upper limit on the ${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section is measured to be 0.59 pb from ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ , which corresponds to about 59 times the SM prediction (gluon fusion). The combined upper limit is 0.43 pb, which is about 43 times the SM prediction. The quoted values are given for ${\mathit m}_{{{\mathit H}^{0}}}$ = 125 GeV.
16  AABOUD 2016I search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ with data of 3.2 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. The upper limit on the ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ production cross section is measured to be 1.22 pb. This result corresponds to about 108 times the SM prediction (gluon fusion), which is $11.3$ ${}^{+0.9}_{-1.0}$ fb (NNLO+NNLL) including top quark mass effects. The quoted values are given for ${\mathit m}_{{{\mathit H}^{0}}}$ = 125 GeV .
17  KHACHATRYAN 2016BQ search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ with data of 19.7 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. The upper limit on the ${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ production is measured to be 1.85 fb, which corresponds to about 74 times the SM prediction and is translated into 0.71 pb for ${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section. Limits on Higgs-boson trilinear coupling $\lambda$ are also given.
18  AAD 2015CE search for ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production using ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ and ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit W}}{{\mathit W}}$ with data of 20.3 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. These results are then combined with the published results of the ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ and ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , which use data of up to 20.3 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. The upper limits on the ${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ production cross section are measured to be 1.6 pb, 11.4 pb, 2.2 pb and 0.62 pb from ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}}{{\mathit \tau}}$ , ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit W}}{{\mathit W}}$ , ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ and ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ , respectively. The combined upper limit is 0.69 pb, which corresponds to about 70 times the SM prediction. The quoted results are given for ${\mathit m}_{{{\mathit H}^{0}}}$ = 125.4 GeV. See their Table 4.
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