MASS LIMITS FOR NEUTRAL HIGGS BOSONS IN EXTENDED HIGGS MODELS

This Section covers models which do not fit into either the Standard Model or its simplest minimal Supersymmetric extension (MSSM), leading to anomalous production rates, or nonstandard final states and branching ratios. In particular, this Section covers limits which may apply to generic two-Higgs-doublet models (2HDM), or to special regions of the MSSM parameter space where decays to invisible particles or to photon pairs are dominant (see the review on Status of Higgs Boson Physics''). Concerning the mass limits for ${{\mathit H}^{0}}$ and ${{\mathit A}^{0}}$ listed below, see the footnotes or the comment lines for details on the nature of the models to which the limits apply.
The observed signal at about 125 GeV, see section ${{\mathit H}^{0}}$'', can be interpreted as one of the neutral Higgs bosons of an extended Higgs sector.

Other Mass Limits INSPIRE search

We use a symbol ${{\mathit H}_{{1}}^{0}}$ if mass $<$ 125 GeV or ${{\mathit H}_{{2}}^{0}}$ if mass $>$ 125 GeV. The notation ${{\mathit H}^{0}}$ is reserved for the 125 GeV particle.

VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
1
 2018 F
CMS ${{\mathit p}}{{\mathit p}}$ , 13 TeV, ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
2
 2017
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$
3
 2017 AW
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$
4
 2017 D
CMS ${{\mathit p}}{{\mathit p}}$ , 8, 13 TeV, ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$
5
 2017 R
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
6
 2017 CN
CMS ${{\mathit p}}{{\mathit p}}$ , 8 TeV, ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
7
 2017 Y
CMS ${{\mathit p}}{{\mathit p}}$ , 8, 13 TeV, ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}}$
8
 2016 AB
ATLS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
9
 2016 AE
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$ , ${{\mathit Z}}{{\mathit Z}}$
10
 2016 H
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
11
 2016 I
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
12
 2016 AX
ATLS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit Z}}$
13
 2016 C
ATLS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$
14
 2016 L
ATLS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
15
 2016 L
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
16
 2016 C
CDF ${{\mathit H}_{{1}}^{0}}$ ${{\mathit H}^{\pm}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit H}_{{1}}^{0}}{{\mathit W}^{*}}$ , ${{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
17
 2016 BG
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
18
 2016 BQ
CMS ${{\mathit p}}{{\mathit p}}$ , 8 TeV, ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
19
 2016 F
CMS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit H}_{{1}}^{0}}$
20
 2016 M
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
21
 2016 P
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
22
 2016 P
CMS ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit H}^{0}}$
23
 2015 BK
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
24
 2015 BZ
ATLS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
25
 2015 BZ
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
26
 2015 CE
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
27
 2015 H
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
28
 2015 S
ATLS ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit H}^{0}}$
29
 2015 AW
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$ , ${{\mathit Z}}{{\mathit Z}}$
30
 2015 BB
CMS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
31
 2015 N
CMS ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit H}^{0}}$
32
 2015 O
CMS ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit H}^{0}}$
33
 2015 R
CMS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$
34
 2014 AP
ATLS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
35
 2014 M
ATLS ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{\pm}}{{\mathit W}^{\mp}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit W}^{\pm}}{{\mathit W}^{\mp}}$ , ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
36
 2014 G
CMS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit W}}{{\mathit W}^{(*)}}$
37
 2014 P
CMS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
38
 2013 P
CDF ${{\mathit H}^{'0}}$ $\rightarrow$ ${{\mathit H}^{\pm}}{{\mathit W}^{\mp}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit W}^{+}}{{\mathit W}^{-}}$
39
 2013 BJ
CMS ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
40
 2011 P
CDF ${{\mathit t}}$ $\rightarrow$ ${{\mathit b}}{{\mathit H}^{+}}$ , ${{\mathit H}^{+}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit A}^{0}}$
41
 2010
OPAL ${{\mathit H}^{0}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$
42
 2010
ALEP ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
43
 2009 V
D0 ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
$\text{none 3 - 63}$ 95 44
 2005 A
OPAL ${{\mathit A}^{0}}$, Type II model
$>104$ 95 45
 2004 K
OPAL ${{\mathit H}^{0}}$ $\rightarrow$ 2 jets
46
 2004
DLPH ${{\mathit H}^{0}}{{\mathit V}}{{\mathit V}}$ couplings
$>110.3$ 95 47
 2004 B
L3 ${{\mathit H}^{0}}$ $\rightarrow$ 2 jets
48
 2004 F
L3 Anomalous coupling
49
 2003 F
OPAL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit Z}}$ , ${{\mathit H}^{0}}$ $\rightarrow$ any
50
 2003 G
OPAL ${{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$
$>105.4$ 95 51, 52
 2002 L
ALEP ${{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
$>109.1$ 95 53
 2002 M
ALEP ${{\mathit H}^{0}}$ $\rightarrow$ 2 jets or ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$\text{none 12 - 56}$ 95 54
 2001 E
OPAL ${{\mathit A}^{0}}$, Type-II model
55
 2000 R
L3 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit \gamma}}$ and/or ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
56
 2000 R
L3 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit H}^{0}}$
57
 1998 B
RVUE Anomalous coupling
58
 1997
RVUE ($\mathit g-2)_{{{\mathit \mu}}}$
59
 1996 H
OPAL ${{\mathit Z}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit \gamma}}$
1  SIRUNYAN 2018F search for a narrow scalar resonance decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit W}}{{\mathit W}}$ ${{\mathit b}}{{\overline{\mathit b}}}$ or ${{\mathit Z}}{{\mathit Z}}{{\mathit b}}{{\overline{\mathit b}}}$ in the final state ${{\mathit \ell}}{{\mathit \ell}}{{\mathit \nu}}{{\mathit \nu}}{{\mathit b}}{{\overline{\mathit b}}}$ in 35.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 7 for limits on cross section times branching ratios for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $250 - 900$ GeV.
2  AABOUD 2017 search for production of a scalar resonance decaying to ${{\mathit Z}}{{\mathit \gamma}}$ in 3.2 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 4 for the limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.25 - 3.0$ TeV.
3  AABOUD 2017AW search for production of a scalar resonance decaying to ${{\mathit Z}}{{\mathit \gamma}}$ in 36.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 7 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.25 - 2.4$ TeV.
4  KHACHATRYAN 2017D search for production of a scalar resonance decaying to ${{\mathit Z}}{{\mathit \gamma}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV and 2.7 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Figs. 3 and 4 for the limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.2 - 2.0$ TeV.
5  KHACHATRYAN 2017R search for production of a narrow scalar resonance decaying to ${{\mathit \gamma}}{{\mathit \gamma}}$ in 12.9 fb${}^{-1}$ (taken in 2016) of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 2 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.5 - 4.5$ TeV for several values of its width-to-mass ratio. Limits from combination with KHACHATRYAN 2016M are shown in their Figs. 4 and 6.
6  SIRUNYAN 2017CN search for a narrow scalar resonance decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 18.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 5 (above) and Table II for limits on the cross section times branching ratios for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.3 - 1$ TeV, and Fig. 6 (above) and Table III for the corresponding limits by combining with data from KHACHATRYAN 2016BQ and KHACHATRYAN 2015R.
7  SIRUNYAN 2017Y search for production of a scalar resonance decaying to ${{\mathit Z}}{{\mathit \gamma}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV and 2.7 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Figs. 3, 4 and Table 3 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.7 - 3.0$ TeV, and Fig. 5 for the corresponding limits for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.2 - 3.0$ TeV from combination with KHACHATRYAN 2017D data.
8  AABOUD 2016AB search for associated production of ${{\mathit W}}{{\mathit H}^{0}}$ with the decay ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ in 3.2 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 8 for limits on cross section times branching ratios for ${\mathit m}_{{{\mathit A}^{0}}}$ = $20 - 60$ GeV.
9  AABOUD 2016AE search for production of a narrow scalar resonance decaying to ${{\mathit W}^{+}}{{\mathit W}^{-}}$ and ${{\mathit Z}}{{\mathit Z}}$ in 3.2 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 4 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.5 - 3$ TeV.
10  AABOUD 2016H search for production of a scalar resonance decaying to ${{\mathit \gamma}}{{\mathit \gamma}}$ in 3.2 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 12 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.2 - 2$ TeV with different assumptions on the width.
11  AABOUD 2016I search for a narrow scalar resonance decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ in 3.2 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 10(c) for limits on cross section times branching ratios for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.5 - 3$ TeV.
12  AAD 2016AX search for production of a heavy ${{\mathit H}^{0}}$ state decaying to ${{\mathit Z}}{{\mathit Z}}$ in the final states ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ , ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit \nu}}{{\overline{\mathit \nu}}}$ , ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit q}}{{\overline{\mathit q}}}$ , and ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit q}}{{\overline{\mathit q}}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig.12 for upper limits on ${\mathit \sigma (}{{\mathit H}^{0}}{)}$ B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit Z}}$ ) for ${\mathit m}_{{{\mathit H}^{0}}}$ ranging from 140 GeV to 1000 GeV.
13  AAD 2016C search for production of a heavy ${{\mathit H}^{0}}$ state decaying to ${{\mathit W}^{+}}{{\mathit W}^{-}}$ in the final states ${{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}}{{\mathit \nu}}$ and ${{\mathit \ell}}{{\mathit \nu}}{{\mathit q}}{{\mathit q}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Figs. 12, 13, and 16 for upper limits on ${\mathit \sigma (}{{\mathit H}^{0}}{)}$ B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$ ) for ${\mathit m}_{{{\mathit H}^{0}}}$ ranging from 300 GeV to 1000 or 1500 GeV with various assumptions on the total width of ${{\mathit H}^{0}}$.
14  AAD 2016L search for the decay ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \gamma}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 4 (upper right) for limits on cross section times branching ratios (normalized to the SM ${{\mathit H}^{0}}$ cross section) for ${\mathit m}_{{{\mathit A}^{0}}}$ = $10 - 60$ GeV.
15  AAD 2016L search for the decay ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \gamma}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 4 (lower right) for limits on cross section times branching ratios for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = 600 GeV and ${\mathit m}_{{{\mathit A}^{0}}}$ = $10 - 245$ GeV, and Table 5 for limits for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$= 300 and 900 GeV.
16  AALTONEN 2016C search for electroweak associated production of ${{\mathit H}_{{1}}^{0}}{{\mathit H}^{\pm}}$ followed by the decays ${{\mathit H}^{\pm}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit W}^{*}}$ , ${{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ for ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}$ = $10 - 105$ GeV and ${\mathit m}_{{{\mathit H}^{\pm}}}$ = $30 - 300$ GeV. See their Fig. 3 for excluded parameter region in a two-doublet model in which ${{\mathit H}_{{1}}^{0}}$ has no direct decay to fermions.
17  KHACHATRYAN 2016BG search for a narrow scalar resonance decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 6 for limits on the cross section times branching ratios for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $1.15 - 3$ TeV.
18  KHACHATRYAN 2016BQ search for a resonance decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 9 for limits on the cross section times branching ratios for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.26 - 1.1$ TeV.
19  KHACHATRYAN 2016F search for the decay ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}$ ${{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 8 for cross section limits for ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}$ = $4 - 8$ GeV.
20  KHACHATRYAN 2016M search for production of a narrow resonance decaying to ${{\mathit \gamma}}{{\mathit \gamma}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV and 3.3 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 3 (top) for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.5 - 4$ TeV.
21  KHACHATRYAN 2016P search for gluon fusion production of an ${{\mathit H}_{{2}}^{0}}$ decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 8 (lower right) for cross section limits for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $260 - 350$ GeV.
22  KHACHATRYAN 2016P search for gluon fusion production of 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. 10 for cross section limits for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $220 - 350$ GeV.
23  AAD 2015BK search for production of a heavy ${{\mathit H}_{{2}}^{0}}$ decaying to ${{\mathit H}^{0}}{{\mathit H}^{0}}$ in the final state ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ in 19.5 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 14(c) for ${\mathit \sigma (}{{\mathit H}_{{2}}^{0}}{)}$ B( ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ ) for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $500 - 1500$ GeV with ${\Gamma}_{{\mathit H}_{{2}}^{0}}$ = 1 GeV.
24  AAD 2015BZ search for the decay ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ (${\mathit m}_{{{\mathit H}^{0}}}$ = 125 GeV) in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 6 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.7 - 50$ GeV.
25  AAD 2015BZ search for a state ${{\mathit H}_{{2}}^{0}}$ via the decay ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 6 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $100 - 500$ GeV and ${\mathit m}_{{{\mathit A}^{0}}}$ = 5 GeV.
26  AAD 2015CE search for production of a heavy ${{\mathit H}_{{2}}^{0}}$ decaying to ${{\mathit H}^{0}}{{\mathit H}^{0}}$ in the final states ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ and ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit W}}{{\mathit W}^{*}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV and combine with data from AAD 2015H and AAD 2015BK. A limit ${\mathit \sigma (}{{\mathit H}_{{2}}^{0}}{)}$ B( ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ ) $<$ $2.1 - 0.011$ pb (95$\%$ CL) is given for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $260 - 1000$ GeV. See their Fig. 6.
27  AAD 2015H search for production of a heavy ${{\mathit H}_{{2}}^{0}}$ decaying to ${{\mathit H}^{0}}{{\mathit H}^{0}}$ in the finalstate ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit b}}{{\overline{\mathit b}}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV.A limit of ${\mathit \sigma (}{{\mathit H}_{{2}}^{0}}{)}$ B( ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit H}^{0}}$ ) $<$ $3.5 - 0.7$ pb is given for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $260 - 500$ GeV at 95$\%$ CL. See their Fig. 3.
28  AAD 2015S search for production of ${{\mathit A}^{0}}$ decaying to ${{\mathit Z}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit b}}{{\overline{\mathit b}}}$ and ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 3 for cross section limits for ${\mathit m}_{{{\mathit A}^{0}}}$ = $200 - 1000$ GeV.
29  KHACHATRYAN 2015AW search for production of a heavy state ${{\mathit H}_{{2}}^{0}}$ of an electroweak singlet extension of the Standard Model via the decays of ${{\mathit H}_{{2}}^{0}}$ to ${{\mathit W}^{+}}{{\mathit W}^{-}}$ and ${{\mathit Z}}{{\mathit Z}}$ in up to 5.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV and up to 19.7 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV in the range ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $145 - 1000$ GeV. See their Figs. 8 and 9 for limits in the parameter space of the model.
30  KHACHATRYAN 2015BB search for production of a resonance ${{\mathit H}^{0}}$ decaying to ${{\mathit \gamma}}{{\mathit \gamma}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 7 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}^{0}}}$ = $150 - 850$ GeV.
31  KHACHATRYAN 2015N search for production of ${{\mathit A}^{0}}$ decaying to ${{\mathit Z}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit b}}{{\overline{\mathit b}}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 3 for limits on cross section times branching ratios for ${\mathit m}_{{{\mathit A}^{0}}}$ = $225 - 600$ GeV.
32  KHACHATRYAN 2015O search for production of a high-mass narrow resonance ${{\mathit A}^{0}}$ decaying to ${{\mathit Z}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 6 for limits on cross section times branching ratios for ${\mathit m}_{{{\mathit A}^{0}}}$ = $800 - 2500$ GeV.
33  KHACHATRYAN 2015R search for a narrow scalar resonance decaying to ${{\mathit H}^{0}}$ ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$ in 17.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 5 (top) for limits on cross section times branching ratios for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$ = $0.27 - 1.1$ TeV.
34  AAD 2014AP search for a second ${{\mathit H}^{0}}$ state decaying to ${{\mathit \gamma}}{{\mathit \gamma}}$ in addition to the state at about 125 GeV in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 4 for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}^{0}}}$ = $65 - 600$ GeV.
35  AAD 2014M search for the decay cascade ${{\mathit H}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}^{\pm}}{{\mathit W}^{\mp}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit W}^{\pm}}{{\mathit W}^{\mp}}$ , ${{\mathit H}^{0}}$ decaying to ${{\mathit b}}{{\overline{\mathit b}}}$ in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Table III for limits on cross section times branching ratio for ${\mathit m}_{{{\mathit H}_{{2}}^{0}}}$= $325 - 1025$ GeV and ${\mathit m}_{{{\mathit H}^{+}}}$= $225 - 925$ GeV.
36  CHATRCHYAN 2014G search for a second ${{\mathit H}^{0}}$ state decaying to ${{\mathit W}}{{\mathit W}^{(*)}}$ in addition to the observed signal at about 125 GeV using 4.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV and 19.4 fb${}^{-1}$ at $\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 21 (right) for cross section limits in the mass range $110 - 600$ GeV.
37  KHACHATRYAN 2014P search for a second ${{\mathit H}^{0}}$ state decaying to ${{\mathit \gamma}}{{\mathit \gamma}}$ in addition to the observed signal at about 125 GeV using 5.1 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. 27 and 28 for cross section limits in the mass range $110 - 150$ GeV.
38  AALTONEN 2013P search for production of a heavy Higgs boson ${{\mathit H}^{'0}}$ that decays into a charged Higgs boson ${{\mathit H}^{\pm}}$ and a lighter Higgs boson ${{\mathit H}^{0}}$ via the decay chain ${{\mathit H}^{'0}}$ $\rightarrow$ ${{\mathit H}^{\pm}}{{\mathit W}^{\mp}}$ , ${{\mathit H}^{\pm}}$ $\rightarrow$ ${{\mathit W}^{\pm}}{{\mathit H}^{0}}$ , ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ in the final state ${{\mathit \ell}}{{\mathit \nu}}$ plus 4 jets in 8.7 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. See their Fig. 4 for limits on cross section times branching ratio in the ${\mathit m}_{{{\mathit H}^{\pm}}}−{\mathit m}_{{{\mathit H}^{'0}}}$ plane for ${\mathit m}_{{{\mathit H}^{0}}}$ = 126 GeV.
39  CHATRCHYAN 2013BJ search for ${{\mathit H}^{0}}$ production in the decay chain ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ , ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in 5.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 2 for limits on cross section times branching ratio.
40  AALTONEN 2011P search in 2.7 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV for the decay chain ${{\mathit t}}$ $\rightarrow$ ${{\mathit b}}{{\mathit H}^{+}}$ , ${{\mathit H}^{+}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit A}^{0}}$ , ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ with ${\mathit m}_{{{\mathit A}^{0}}}$ between 4 and 9 GeV. See their Fig.$~$4 for limits on B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit b}}{{\mathit H}^{+}}$ ) for 90 $<$ ${\mathit m}_{{{\mathit H}^{+}}}<$ 160 GeV.
41  ABBIENDI 2010 search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit H}^{0}}$ with the decay chain ${{\mathit H}^{0}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$ , ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ + (${{\mathit \gamma}}$ or ${{\mathit Z}^{*}}$), when ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ are nearly degenerate. For a mass difference of 2 (4) GeV, a lower limit on ${\mathit m}_{{{\mathit H}^{0}}}$ of 108.4 (107.0) GeV (95$\%$ CL) is obtained for SM ${{\mathit Z}}{{\mathit H}^{0}}$ cross section and B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$ ) = 1.
42  SCHAEL 2010 search for the process ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit Z}}$ followed by the decay chain ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ with ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ , ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ at $\mathit E_{{\mathrm {cm}}}$ = $183 - 209$ GeV. For a ${{\mathit H}^{0}}{{\mathit Z}}{{\mathit Z}}$ coupling equal to the SM value, B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ ) = B( ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ ) = 1, and ${\mathit m}_{{{\mathit A}^{0}}}$ = $4 - 10$ GeV, ${\mathit m}_{{{\mathit H}^{0}}}$ up to 107 GeV is excluded at 95$\%$ CL.
43  ABAZOV 2009V search for ${{\mathit H}^{0}}$ production followed by the decay chain ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ or ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in 4.2 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. See their Fig. 3 for limits on $\sigma ({{\mathit H}^{0}})\cdot{}$B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ ) for ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.6 - 19$ GeV.
44  ABBIENDI 2005A search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}_{{1}}^{0}}{{\mathit A}^{0}}$ in general Type-II two-doublet models, with decays ${{\mathit H}_{{1}}^{0}}$, ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ , ${{\mathit g}}{{\mathit g}}$ , ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ , and ${{\mathit H}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit A}^{0}}{{\mathit A}^{0}}$ .
45  ABBIENDI 2004K search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit Z}}$ with ${{\mathit H}^{0}}$ decaying to two jets of any flavor including ${{\mathit g}}{{\mathit g}}$ . The limit is for SM production cross section with B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit j}}{{\mathit j}}$ ) = 1.
46  ABDALLAH 2004 consider the full combined LEP and LEP2 datasets to set limits on the Higgs coupling to ${{\mathit W}}$ or ${{\mathit Z}}$ bosons, assuming SM decays of the Higgs. Results in Fig. 26.
47  ACHARD 2004B search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit Z}}$ with ${{\mathit H}^{0}}$ decaying to ${{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit c}}{{\overline{\mathit c}}}$ , or ${{\mathit g}}{{\mathit g}}$ . The limit is for SM production cross section with B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit j}}{{\mathit j}}$ ) = 1.
48  ACHARD 2004F search for ${{\mathit H}^{0}}$ with anomalous coupling to gauge boson pairs in the processes ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit \gamma}}$ , ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit H}^{0}}$ , ${{\mathit H}^{0}}{{\mathit Z}}$ with decays ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit f}}{{\overline{\mathit f}}}$ , ${{\mathit \gamma}}{{\mathit \gamma}}$ , ${{\mathit Z}}{{\mathit \gamma}}$ , and ${{\mathit W}^{*}}{{\mathit W}}$ at $\mathit E_{{\mathrm {cm}}}$ = $189 - 209$ GeV. See paper for limits.
49  ABBIENDI 2003F search for ${{\mathit H}^{0}}$ $\rightarrow$ anything in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit Z}}$ , using the recoil mass spectrum of ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ or ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ . In addition, it searched for ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ and ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ or photons. Scenarios with large width or continuum ${{\mathit H}^{0}}$ mass distribution are considered. See their Figs. 11--14 for the results.
50  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 region ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}$ = 45-86 GeV and ${\mathit m}_{{{\mathit A}^{0}}}$ = 2-11 GeV. See their Fig. 7 for the limits.
51  Search for associated production of a ${{\mathit \gamma}}{{\mathit \gamma}}$ resonance with a ${{\mathit Z}}~$boson, followed by ${{\mathit Z}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ , ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ , or ${{\mathit \nu}}{{\overline{\mathit \nu}}}$ , at $\mathit E_{{\mathrm {cm}}}{}\leq{}$209 GeV. The limit is for a ${{\mathit H}^{0}}$ with SM production cross section and B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit f}}{{\overline{\mathit f}}}$ )=0 for all fermions ${{\mathit f}}$.
52  For B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ )=1, ${\mathit m}_{{{\mathit H}^{0}}}>113.1$ GeV is obtained.
53  HEISTER 2002M search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit Z}}$ , assuming that ${{\mathit H}^{0}}$ decays to ${{\mathit q}}{{\overline{\mathit q}}}$ , ${{\mathit g}}{{\mathit g}}$ , or ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ only. The limit assumes SM production cross section.
54  ABBIENDI 2001E search for neutral Higgs bosons in general Type-II two-doublet models, at $\mathit E_{{\mathrm {cm}}}{}\leq{}$189 GeV. In addition to usual final states, the decays ${{\mathit H}_{{1}}^{0}}$, ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ , ${{\mathit g}}{{\mathit g}}$ are searched for. See their Figs.$~$15,16 for excluded regions.
55  ACCIARRI 2000R search for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit \gamma}}$ with ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ , ${{\mathit Z}}{{\mathit \gamma}}$ , or ${{\mathit \gamma}}{{\mathit \gamma}}$ . See their Fig.$~$3 for limits on $\sigma \cdot{}$B. Explicit limits within an effective interaction framework are also given, for which the Standard Model Higgs search results are used in addition.
56  ACCIARRI 2000R search for the two-photon type processes ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit H}^{0}}$ with ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ or ${{\mathit \gamma}}{{\mathit \gamma}}$ . See their Fig.$~$4 for limits on $\Gamma\mathrm {( {{\mathit H}^{0}} \rightarrow {{\mathit \gamma}} {{\mathit \gamma}} )}\cdot{}$B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ or ${{\mathit b}}{{\overline{\mathit b}}}$ ) for ${\mathit m}_{{{\mathit H}^{0}}}=70 - 170$ GeV.
57  GONZALEZ-GARCIA 1998B use ${D0}$ limit for ${{\mathit \gamma}}{{\mathit \gamma}}$ events with missing $\mathit E_{\mathit T}$ in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions (ABBOTT 1998 ) to constrain possible ${{\mathit Z}}{{\mathit H}}$ or ${{\mathit W}}{{\mathit H}}$ production followed by unconventional ${{\mathit H}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ decay which is induced by higher-dimensional operators. See their Figs.$~$1 and$~$2 for limits on the anomalous couplings.
58  KRAWCZYK 1997 analyse the muon anomalous magnetic moment in a two-doublet Higgs model (with type$~$II Yukawa couplings) assuming no ${{\mathit H}_{{1}}^{0}}{{\mathit Z}}{{\mathit Z}}$ coupling and obtain ${\mathit m}_{{{\mathit H}_{{1}}^{0}}}{ {}\gtrsim{} }5$ GeV or ${\mathit m}_{{{\mathit A}^{0}}}{ {}\gtrsim{} }5$ GeV for tan $\beta >50$. Other Higgs bosons are assumed to be much heavier.
59  ALEXANDER 1996H give B( ${{\mathit Z}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit \gamma}}$ )${\times }$B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ ) $<1 - 4 \times 10^{-5}$ (95$\%$CL) and B( ${{\mathit Z}}$ $\rightarrow$ ${{\mathit H}^{0}}{{\mathit \gamma}}$ )${\times }$B( ${{\mathit H}^{0}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ ) $<0.7 - 2 \times 10^{-5}$ (95$\%$CL) in the range 20 $<{\mathit m}_{{{\mathit H}^{0}}}$ $<$80 GeV.
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