# MASS LIMITS FOR NEUTRAL HIGGS BOSONS IN SUPERSYMMETRIC MODELS

The minimal supersymmetric model has two complex doublets of Higgs bosons. The resulting physical states are two scalars [${{\mathit H}_{{1}}^{0}}$ and ${{\mathit H}_{{2}}^{0}}$, where we define ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}$ $<$ ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$], a pseudoscalar (${{\mathit A}^{0}}$), and a charged Higgs pair (${{\mathit H}^{\pm}}$). ${{\mathit H}_{{1}}^{0}}$ and ${{\mathit H}_{{2}}^{0}}$ are also called ${{\mathit h}}$ and ${{\mathit H}}$ in the literature. There are two free parameters in the Higgs sector which can be chosen to be ${\mathit m}_{{{\mathit A}^{0}}}$ and tan $\beta$ = $\mathit v_{2}/\mathit v_{1}$, the ratio of vacuum expectation values of the two Higgs doublets. Tree-level Higgs masses are constrained by the model to be ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}{}\leq{}{\mathit m}_{{{\mathit Z}}}$, ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}{}\geq{}{\mathit m}_{{{\mathit Z}}}$, ${\mathit m}_{{{\mathit A}^{0}}}{}\geq{}{\mathit m}_{{{\mathit H}_{{1}}^{0}}}$, and ${\mathit m}_{{{\mathit H}^{\pm}}}{}\geq{}{\mathit m}_{{{\mathit W}}}$. However, as described in the review on Status of Higgs Boson Physics'' in this Volume these relations are violated by radiative corrections.
The observed signal at about 125 GeV, see section ${{\mathit H}^{0}}$'', can be interpreted as one of the neutral Higgs bosons of supersymmetric models. Unless otherwise noted, we identify the lighter scalar ${{\mathit H}_{{1}}^{0}}$ with the Higgs discovered at 125 GeV at the LHC (AAD 2012AI, CHATRCHYAN 2012N).
Unless otherwise noted, the experiments in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions search for the processes ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit Z}^{0}}$ in the channels used for the Standard Model Higgs searches and ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit A}^{0}}$ in the final states ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ and ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ . Unless otherwise stated, the following results assume no invisible ${{\mathit H}_{{1}}^{0}}$ or ${{\mathit A}^{0}}$ decays. Unless otherwise noted, the results are given in the m${}^{max}_{h}$ scenario, CARENA 2013 .
In ${{\mathit p}}{{\overline{\mathit p}}}$ and ${{\mathit p}}{{\mathit p}}$ collisions the experiments search for a variety of processes, as explicitly specified for each entry. Limits on the ${{\mathit A}^{0}}$ mass arise from these direct searches, as well as from the relations valid in the minimal supersymmetric model between ${\mathit m}_{{{\mathit A}^{0}}}$ and ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}$. As discussed in the review on Status of Higgs Boson Physics'' in this Volume, these relations depend, via potentially large radiative corrections, on the mass of the ${{\mathit t}}~$quark and on the supersymmetric parameters, in particular those of the stop sector. These indirect limits are weaker for larger ${{\mathit t}}$ and ${{\widetilde{\mathit t}}}$ masses. To include the radiative corrections to the Higgs masses, unless otherwise stated, the listed papers use theoretical predictions incorporating two-loop corrections, and the results are given for the m${}^{mod+}_{h}$ benchmark scenario, see CARENA 2013 .

# Mass Limits for heavy neutral Higgs bosons (${{\boldsymbol H}_{{2}}^{0}}$, ${{\boldsymbol A}^{0}}$) in the MSSM INSPIRE search

The limits rely on ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ and assume that ${{\mathit H}_{{2}}^{0}}$ and ${{\mathit A}^{0}}$ are (sufficiently) mass degenerate. The limits depend on tan $\beta$.
VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT
$\bf{> 377}$ 95 1
 2018 G
ATLS tan $\beta$ = 10 GeV
$> 863$ 95 1
 2018 G
ATLS tan $\beta$ = 20 GeV
$> 1157$ 95 1
 2018 G
ATLS tan $\beta$ = 30 GeV
$> 1328$ 95 1
 2018 G
ATLS tan $\beta$ = 40 GeV
$> 1483$ 95 1
 2018 G
ATLS tan $\beta$ = 50 GeV
$\bf{> 1613}$ 95 1
 2018 G
ATLS tan $\beta$ = 60 GeV
$> 389$ 95 2
 2018 CX
CMS tan $\beta$ = 10 GeV
$> 832$ 95 2
 2018 CX
CMS tan $\beta$ = 20 GeV
$> 1148$ 95 2
 2018 CX
CMS tan $\beta$ = 30 GeV
$> 1341$ 95 2
 2018 CX
CMS tan $\beta$ = 40 GeV
$> 1496$ 95 2
 2018 CX
CMS tan $\beta$ = 50 GeV
$\bf{> 1613}$ 95 2
 2018 CX
CMS tan $\beta$ = 60 GeV
• • • We do not use the following data for averages, fits, limits, etc. • • •
3
 2018 A
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
4
 2018 BP
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit b}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
5
 2016 AA
ATLS ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
6
 2016 A
CMS ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
7
 2016 P
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ , ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit H}^{0}}$
8
 2015 AY
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit b}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
9
 2014 AW
ATLS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}}{{\mathit \tau}}$
10
 2014 M
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}}{{\mathit \tau}}$
11
 2013 O
ATLS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
12
 2013 T
LHCB ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
13
 2013 AG
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit b}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
14
 2012 AQ
TEVA ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit b}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
15
 2012 X
CDF ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit b}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
16
 2012 G
D0 ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
17
 2012 K
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
18
 2011 K
D0 ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit b}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
19
 2011 W
D0 ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit b}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
20
 2009 AR
CDF ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$ , ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$> 90.4$ 21
 2008 B
DLPH $\mathit E_{{\mathrm {cm}}}{}\leq{}$209 GeV
$> 93.4$ 95 22
 2006 B
LEP $\mathit E_{{\mathrm {cm}}}{}\leq{}$209 GeV
23
 2005 Q
CDF ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}{+}$ ${{\mathit X}}$
$>85.0$ 95 24, 25
 2004 M
OPAL $\mathit E_{{\mathrm {cm}}}{}\leq{}$209 GeV
26
 2003 G
OPAL ${{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
$>86.5$ 95 24, 27
 2002 H
L3 $\mathit E_{{\mathrm {cm}}}{}\leq{}$209 GeV, tan $\beta >0.4$
28
 2002
RVUE
$>90.1$ 95 24, 29
 2002
ALEP $\mathit E_{{\mathrm {cm}}}{}\leq{}$209 GeV, tan $\beta >0.5$
1  AABOUD 2018G search for production of ${{\mathit H}_{{2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ by gluon fusion and ${{\mathit b}}$-associated prodution in 36.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 10 for excluded regions in the ${\mathit m}_{{{\mathit A}^{0}}}-$ tan $\beta$ plane in several MSSM scenarios.
2  SIRUNYAN 2018CX search for production of ${{\mathit H}_{{{1,2}}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ by gluon fusion and ${{\mathit b}}$-associated prodution in 35.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 9 for excluded regions in the ${\mathit m}_{{{\mathit A}^{0}}}-$ tan $(\beta )$ plane in several MSSM scenarios.
3  SIRUNYAN 2018A search for production of a scalar resonance decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 35.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 5 (lower) for excluded regions in the ${\mathit m}_{{{\mathit A}^{0}}}$ $−$ tan ${{\mathit \beta}}$ plane in the hMSSM scenario.
4  SIRUNYAN 2018BP search for production of ${{\mathit H}_{{2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ by ${{\mathit b}}$-associated prodution in 35.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 6 for the limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$, ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.3 - 1.3$ TeV, and Fig. 7 for excluded regions in the ${\mathit m}_{{{\mathit A}^{0}}}-$ tan $(\beta )$ plane in several MSSM scenarios.
5  AABOUD 2016AA search for production of a Higgs boson in gluon fusion and in association with a ${{\mathit b}}{{\overline{\mathit b}}}$ pair followed by the decay ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 3.2 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 5(a, b) for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit A}^{0}}}$ = $200 - 1200$ GeV, and Fig. 5(c, d) for the excluded region in the MSSM parameter space in the ${{\mathit m}}{}^{{\mathrm {mod+}}}_{h}$ and hMSSM scenarios.
6  KHACHATRYAN 2016A search for production of a Higgs boson in gluon fusion and in association with a ${{\mathit b}}{{\overline{\mathit b}}}$ pair followed by the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in 5.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV and 19.3 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 7 for the excluded region in the MSSM parameter space in the ${{\mathit m}}{}^{{\mathrm {mod+}}}_{h}$ benchmark scenario and Fig. 9 for limits on cross section times branching ratio.
7  KHACHATRYAN 2016P search for gluon fusion production of an ${{\mathit H}_{{2}}^{0}}$ decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ and an ${{\mathit A}^{0}}$ decaying to ${{\mathit Z}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 12 for excluded region in the tan $\beta$ $−$ cos $(\beta −\alpha )$ plane for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = ${\mathit m}_{{{\mathit A}^{0}}}$ = 300 GeV.
8  KHACHATRYAN 2015AY search for production of a Higgs boson in association with a ${{\mathit b}}$ quark in the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV and combine with 7 TeV data. See their Fig. 6 for the limits on cross section times branching ratio for ${\mathit m}_{{{\mathit A}^{0}}}$ = $100 - 900$ GeV and Figs. $7 - 9$ for the excluded region in the MSSM parameter space in various benchmark scenarios.
9  AAD 2014AW search for production of a Higgs boson followed by the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 19.5--20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 11 for the limits on cross section times branching ratio and their Figs. 9 and 10 for the excluded region in the MSSM parameter space. For ${\mathit m}_{{{\mathit A}^{0}}}$ = 140 GeV, the region tan ${{\mathit \beta}}>$ 5.4 is excluded at 95$\%$ CL in the ${{\mathit m}}{}^{{\mathrm {max}}}_{h}$ scenario.
10  KHACHATRYAN 2014M search for production of a Higgs boson in gluon fusion and in association with a ${{\mathit b}}$ quark followed by the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 4.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV and 19.7 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Figs. 7 and 8 for one- and two-dimensional limits on cross section times branching ratio and their Figs. 5 and 6 for the excluded region in the MSSM parameter space. For ${\mathit m}_{{{\mathit A}^{0}}}$ = 140 GeV, the region tan ${{\mathit \beta}}>$ 3.8 is excluded at 95$\%$ CL in the ${{\mathit m}}{}^{{\mathrm {max}}}_{h}$ scenario.
11  AAD 2013O search for production of a Higgs boson in the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ and ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ with $4.7 - 4.8$ fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 6 for the excluded region in the MSSM parameter space and their Fig. 7 for the limits on cross section times branching ratio. For ${\mathit m}_{{{\mathit A}^{0}}}$ = $110 - 170$ GeV, tan ${{\mathit \beta}}{ {}\gtrsim{} }$ 10 is excluded, and for tan ${{\mathit \beta}}$ = 50, ${\mathit m}_{{{\mathit A}^{0}}}$ below 470 GeV is excluded at 95$\%$ CL in the $\mathit m{}^{{\mathrm {max}}}_{h}$ scenario.
12  AAIJ 2013T search for production of a Higgs boson in the forward region in the decay ${{\mathit H}_{{1,2}}^{0}}$/ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 1.0 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 2 for the limits on cross section times branching ratio and the excluded region in the MSSM parameter space.
13  CHATRCHYAN 2013AG search for production of a Higgs boson in association with a ${{\mathit b}}$ quark in the decay ${{\mathit H}_{{1,2}}^{0}}$/ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ in $2.7 - 4.8$ fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 6 for the excluded region in the MSSM parameter space and Fig. 5 for the limits on cross section times branching ratio. For ${\mathit m}_{{{\mathit A}^{0}}}$ = $90 - 350$ GeV, upper bounds on tan ${{\mathit \beta}}$ of $18 - 42$ at 95$\%$ CL are obtained in the $\mathit m{}^{{\mathrm {max}}}_{h}$ scenario with ${{\mathit \mu}}$ = +200 GeV.
14  AALTONEN 2012AQ combine AALTONEN 2012X and ABAZOV 2011K. See their Table I and Fig. 1 for the limit on cross section times branching ratio and Fig. 2 for the excluded region in the MSSM parameter space.
15  AALTONEN 2012X search for associated production of a Higgs boson and a ${{\mathit b}}$ quark in the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ , with 2.6 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. See their Table III and Fig. 15 for the limit on cross section times branching ratio and Figs. 17, 18 for the excluded region in the MSSM parameter space.
16  ABAZOV 2012G search for production of a Higgs boson in the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ with 7.3 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV and combine with ABAZOV 2011W and ABAZOV 2011K. See their Figs. 4, 5, and 6 for the excluded region in the MSSM parameter space. For ${\mathit m}_{{{\mathit A}^{0}}}$ = $90 - 180$ GeV, tan ${{\mathit \beta}}{ {}\gtrsim{} }$ 30 is excluded at 95$\%$ CL. in the $\mathit m{}^{{\mathrm {max}}}_{h}$ scenario.
17  CHATRCHYAN 2012K search for production of a Higgs boson in the decay ${{\mathit H}_{{1,2}}^{0}}$ $/$ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ with 4.6 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 3 and Table 4 for the excluded region in the MSSM parameter space. For ${\mathit m}_{{{\mathit A}^{0}}}$ = 160 GeV, the region tan ${{\mathit \beta}}$ $>$ 7.1 is excluded at 95$\%$ CL in the $\mathit m{}^{{\mathrm {max}}}_{h}$ scenario. Superseded by KHACHATRYAN 2014M.
18  ABAZOV 2011K search for associated production of a Higgs boson and a ${{\mathit b}}$ quark, followed by the decay ${{\mathit H}_{{1,2}}^{0}}$/ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ , in 5.2 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. See their Fig.$~$5/Table$~$2 for the limit on cross section times branching ratio and Fig.$~$6 for the excluded region in the MSSM parameter space for ${{\mathit \mu}}$ = $-200$ GeV.
19  ABAZOV 2011W search for associated production of a Higgs boson and a ${{\mathit b}}$ quark, followed by the decay ${{\mathit H}_{{1,2}}^{0}}$/ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}}{{\mathit \tau}}$ , in 7.3 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. See their Fig.$~$2 for the limit on cross section times branching ratio and for the excluded region in the MSSM parameter space.
20  AALTONEN 2009AR search for Higgs bosons decaying to ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in two doublet models in 1.8 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. See their Fig. 2 for the limit on $\sigma \cdot{}$B( ${{\mathit H}^{0}_{{{1,2}}}}$ / ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ ) for different Higgs masses, and see their Fig. 3 for the excluded region in the MSSM parameter space.
21  ABDALLAH 2008B give limits in eight $\mathit CP$-conserving benchmark scenarios and some $\mathit CP$-violating scenarios. See paper for excluded regions for each scenario. Supersedes ABDALLAH 2004 .
22  SCHAEL 2006B make a combined analysis of the LEP data. The quoted limit is for the $\mathit m{}^{{\mathrm {max}}}_{h}$ scenario with ${\mathit m}_{{{\mathit t}}}$ = 174.3 GeV. In the $\mathit CP$-violating CPX scenario no lower bound on ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}$ can be set at 95$\%$ CL. See paper for excluded regions in various scenarios. See Figs. $2 - 6$ and Tabs. $14 - 21$ for limits on ${\mathit \sigma (}$ ${{\mathit Z}}{{\mathit H}^{0}}{)}\cdot{}$ B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ ) and ${\mathit \sigma (}$ ${{\mathit H}_{{1}}^{0}}{{\mathit H}_{{2}}^{0}}{)}\cdot{}$ B(${{\mathit H}_{{1}}^{0}},{{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ ).
23  ACOSTA 2005Q search for ${{\mathit H}^{0}_{{{1,2}}}}/{{\mathit A}^{0}}$ production in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.8 TeV with ${{\mathit H}^{0}_{{{1,2}}}}$/ ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ . At ${\mathit m}_{{{\mathit A}^{0}}}$ = 100 GeV, the obtained cross section upper limit is above theoretical expectation.
24  Search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit A}^{0}}$ in the final states ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ and ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ , and ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit Z}}$ . Universal scalar mass of 1$~$TeV, SU(2) gaugino mass of 200 GeV, and $\mu$= $-200$ GeV are assumed, and two-loop radiative corrections incorporated. The limits hold for ${\mathit m}_{{{\mathit t}}}$=175 GeV, and for the $\mathit m{}^{{\mathrm {max}}}_{h}$ scenario.
25  ABBIENDI 2004M exclude 0.7 $<$ tan ${{\mathit \beta}}$ $<$ 1.9, assuming ${\mathit m}_{{{\mathit t}}}$ = 174.3 GeV. Limits for other MSSM benchmark scenarios, as well as for $\mathit CP$ violating cases, are also given.
26  ABBIENDI 2003G search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit Z}}$ followed by ${{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ , ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit c}}{{\overline{\mathit c}}}$ , ${{\mathit g}}{{\mathit g}}$ , or ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ . In the no-mixing scenario, the region ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}$ = 45-85 GeV and ${\mathit m}_{{{\mathit A}^{0}}}$ = 2-9.5 GeV is excluded at 95$\%$ CL.
27  ACHARD 2002H also search for the final state ${{\mathit H}_{{1}}^{0}}$ ${{\mathit Z}}$ $\rightarrow$ 2 ${{\mathit A}^{0}}{{\mathit q}}{{\overline{\mathit q}}}$ , ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ . In addition, the MSSM parameter set in the large-$\mu$'' and no-mixing'' scenarios are examined.
28  AKEROYD 2002 examine the possibility of a light ${{\mathit A}^{0}}$ with tan $\beta <$1. Electroweak measurements are found to be inconsistent with such a scenario.
29  HEISTER 2002 excludes the range $0.7<$tan $\beta <2.3$. A wider range is excluded with different stop mixing assumptions. Updates BARATE 2001C.
References:
 AABOUD 2018G
JHEP 1801 055 Search for Additional Heavy Neutral Higgs and Gauge Bosons in the ditau Final State Produced in 36 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 13 TeV with the ATLAS Detector
 SIRUNYAN 2018CX
JHEP 1809 007 Search for additional neutral MSSM Higgs bosons in the $\tau\tau$ final state in proton-proton collisions at $\sqrt{s}=$ 13 TeV
 SIRUNYAN 2018BP
JHEP 1808 113 Search for beyond the standard model Higgs bosons decaying into a $\mathrm{b\overline{b}}$ pair in pp collisions at $\sqrt{s} =$ 13 TeV
 SIRUNYAN 2018A
PL B778 101 Search for Higgs Boson Pair Production in Events with Two Bottom Quarks and Two Tau Leptons in Proton-Proton Collisions at $\sqrt {s }$ = 13 TeV
 AABOUD 2016AA
EPJ C76 585 Search for Minimal Supersymmetric Standard Model Higgs Bosons $\mathit H/\mathit A$ and for a ${{\mathit Z}^{\,'}}$ Boson in the ${{\mathit \tau}}{{\mathit \tau}}$ Final State Produced in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 13 TeV with the ATLAS Detector
 KHACHATRYAN 2016P
PL B755 217 Searches for a Heavy Scalar Boson ${{\mathit H}}$ Decaying to a Pair of 125 GeV Higgs Bosons ${{\mathit h}}{{\mathit h}}$ or for a Heavy Pseudoscalar Boson ${{\mathit A}}$ Decaying to ${{\mathit Z}}{{\mathit h}}$, in the Final States with ${{\mathit h}}$ $\rightarrow$ ${{\mathit \tau}}{{\mathit \tau}}$
 KHACHATRYAN 2016A
PL B752 221 Search for Neutral MSSM Higgs Bosons Decaying to ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 and 8 TeV
 KHACHATRYAN 2015AY
JHEP 1511 071 Search for Neutral MSSM Higgs Bosons Decaying into a Pair of Bottom Quarks
JHEP 1411 056 Search for Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 8 TeV with the ATLAS Detector
 KHACHATRYAN 2014M
JHEP 1410 160 Search for Neutral MSSM Higgs Bosons Decaying to a Pair of tau Leptons in ${{\mathit p}}{{\mathit p}}$ Collisions
JHEP 1302 095 Search for the Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV with the ATLAS Detector
 AAIJ 2013T
JHEP 1305 132 Limits on Neutral Higgs Boson Production in the Forward Region in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV
 CHATRCHYAN 2013AG
PL B722 207 Search for a Higgs Boson Decaying into a ${\mathit {\mathit b}}$-Quark Pair and Produced in Association with ${\mathit {\mathit b}}$ Quarks in Proton$−$Proton Collisions at 7 TeV
 AALTONEN 2012AQ
PR D86 091101 Search for Neutral Higgs Bosons in Events with Multiple Bottom Quarks at the Tevatron
 AALTONEN 2012X
PR D85 032005 Search for Higgs Bosons Produced in Association with ${\mathit {\mathit b}}$ Quarks
 ABAZOV 2012G
PL B710 569 Search for Higgs Bosons of the Minimal Supersymmetric Standard Model in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 7 TeV
 CHATRCHYAN 2012K
PL B713 68 Search for Neutral Higgs Bosons Decaying to tau Pairs in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV
 ABAZOV 2011K
PL B698 97 Search for Neutral Higgs Bosons in the Multi-${\mathit {\mathit b}}$-Jet Topology in 5.2 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96 TeV
 ABAZOV 2011W
PRL 107 121801 Search for Neutral Minimal Supersymmetric Standard Model Higgs Bosons Decaying to Tau Pairs Produced in Association with ${\mathit {\mathit b}}$ Quarks in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96 TeV
 AALTONEN 2009AR
PRL 103 201801 Search for Higgs Bosons Predicted in Two-Higgs-Doublet Models via Decays to Tau Lepton Pairs in 1.96 TeV ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions
 ABDALLAH 2008B
EPJ C54 1 Higgs Boson Searches in $\mathit CP$-Conserving and $\mathit CP$-Violating MSSM Scenarios with the DELPHI Detector
 SCHAEL 2006B
EPJ C47 547 Search for Neutral MSSM Higgs Bosons at LEP
 ACOSTA 2005Q
PR D72 072004 Search for Supersymmetric Higgs Bosons in the di-tau Decay Mode in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.8 TeV
 ABBIENDI 2004M
EPJ C37 49 Search for Neutral Higgs Boson in $\mathit CP$-Conserving and $\mathit CP$-Violating MSSM Scenarios
 ABBIENDI 2003G
EPJ C27 483 Search for a Low Mass $\mathit CP$ Odd Higgs Boson in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions with the OPAL Detector at LEP-2
 ACHARD 2002H
PL B545 30 Search for Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Interactions at $\sqrt {s }$ = 209-GeV
 AKEROYD 2002
PR D66 037702 On the Possibility of a Very Light ${{\mathit A}^{0}}$ at Low tan$\beta$ in the Minimal Supersymmetric Standard Mdel
 HEISTER 2002
PL B526 191 Final Results of the Searches for Neutral Higgs Bosons in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at$\sqrt {s }$ up to 209 GeV