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 “

${{\mathit H}}$ '', can be interpreted as one of the neutral Higgs bosons of an extended Higgs sector.

Mass Limits for ${{\mathit H}^{0}}$ Decaying to Invisible Final States INSPIRE search

These limits are for a neutral scalar

${{\mathit H}^{0}}$ which predominantly decays to invisible final states. Standard Model values are assumed for the couplings of

${{\mathit H}^{0}}$ to ordinary particles unless otherwise stated.

S055H2I

VALUE (GeV)

CL%

DOCUMENT ID

TECN

COMMENT

• • • We do not use the following data for averages, fits, limits, etc. • • •

AABOUD

2019

ATLS

${{\mathit W}}{{\mathit W}}/{{\mathit Z}}{{\mathit Z}}$ fusion

AAD

2015

ATLS

${{\mathit p}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit W}}{{\mathit X}}$ ,

${{\mathit H}^{0}}{{\mathit Z}}{{\mathit X}}$

AAD

2015

ATLS

jet + missing

$\mathit E_{T}$

⁴

AAD

2014

ATLS

secondary vertex

⁵

AAD

2014

ATLS

${{\mathit p}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}{{\mathit X}}$

⁶

CHATRCHYAN

2014

CMS

${{\mathit p}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}{{\mathit X}}$ ,

${{\mathit q}}{{\mathit q}}{{\mathit H}^{0}}{{\mathit X}}$

⁷

AAD

2013

ATLS

secondary vertex

⁸

AAD

2013

ATLS

electron jets

⁹

CHATRCHYAN

2013

CMS

¹⁰

AAD

2012

ATLS

secondary vertex

¹¹

AALTONEN

2012

CDF

secondary vertex

¹²

AALTONEN

2012

CDF

secondary vertex

$> 108.2$

¹³

ABBIENDI

2010

OPAL

¹⁴

ABBIENDI

2007

OPAL

large width

$> 112.3$

¹⁵

ACHARD

2005

$>112.1$

¹⁵

ABDALLAH

2004

DLPH

$>114.1$

¹⁵

HEISTER

2002

ALEP

$\mathit E_{{\mathrm {cm}}}{}\leq{}$ 209 GeV

$>106.4$

¹⁵

BARATE

2001

ALEP

$\mathit E_{{\mathrm {cm}}}{}\leq{}$ 202 GeV

$>89.2$

¹⁶

ACCIARRI

2000

¹ AABOUD 2019AI search for

${{\mathit H}_{{{{1,2}}}}^{0}}$ production by vector boson fusion and decay to invisible final states in 36.1 fb

${}^{-1}$ of

${{\mathit p}}{{\mathit p}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 13 TeV. See their Fig. 6(b) for limits on cross section times branching ratios for

${\mathit m}_{{{\mathit H}_{{{{1,2}}}}^{0}}}$ =

$0.1 - 3$ TeV.

² AAD 2015BD search for

${{\mathit p}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit W}}{{\mathit X}}$ and

${{\mathit p}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}{{\mathit X}}$ with

${{\mathit W}}$ or

${{\mathit Z}}$ decaying hadronically and

${{\mathit H}^{0}}$ decaying to invisible final states in 20.3 fb

${}^{-1}$ at

$\mathit E_{{\mathrm {cm}}}$ = 8TeV. See their Fig. 6 for a limit on the cross section times branching ratio for

${\mathit m}_{{{\mathit H}^{0}}}$ =

$115 - 300$ GeV.

³ AAD 2015BH search for events with a jet and missing

$\mathit E_{T}$ in 20.3 fb

${}^{-1}$ of

${{\mathit p}}{{\mathit p}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 8 TeV. Limits on

${\mathit \sigma (}{{\mathit H}^{'0}}{)}$ B(

${{\mathit H}^{'0}}$

$\rightarrow$ invisible)

$<$ (

$44 - 10$ ) pb (95

$\%$ CL) is given for

${\mathit m}_{{{\mathit H}^{'0}}}$ =

$115 - 300$ GeV.

⁴ AAD 2014BA search for

${{\mathit H}^{0}}$ production in the decay mode

${{\mathit H}^{0}}$

$\rightarrow$

${{\mathit X}^{0}}{{\mathit X}^{0}}$ , where

${{\mathit X}^{0}}$ is a long-lived particle which decays to collimated pairs of

${{\mathit e}^{+}}{{\mathit e}^{-}}$ ,

${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , or

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ plus invisible particles, in 20.3 fb

${}^{-1}$ of

${{\mathit p}}{{\mathit p}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Figs. 15 and 16 for limits on cross section times branching ratio.

⁵ AAD 2014O search for

${{\mathit p}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}{{\mathit X}}$ ,

${{\mathit Z}}$

$\rightarrow$

${{\mathit \ell}}{{\mathit \ell}}$ , with

${{\mathit H}^{0}}$ decaying to invisible final states in 4.5 fb

${}^{-1}$ at

$\mathit E_{{\mathrm {cm}}}$ = 7 TeV and 20.3 fb

${}^{-1}$ at

$\mathit E_{{\mathrm {cm}}}$ = 8 TeV. See their Fig. 3 for a limit on the cross section times branching ratio for

${\mathit m}_{{{\mathit H}^{0}}}$ =

$110 - 400$ GeV.

⁶ CHATRCHYAN 2014B search for

${{\mathit p}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}{{\mathit X}}$ ,

${{\mathit Z}}$

$\rightarrow$

${{\mathit \ell}}{{\mathit \ell}}$ and

${{\mathit Z}}$

$\rightarrow$

${{\mathit b}}{{\overline{\mathit b}}}$ , and also

${{\mathit p}}$

$\rightarrow$

${{\mathit q}}{{\mathit q}}{{\mathit H}^{0}}{{\mathit X}}$ with

${{\mathit H}^{0}}$ decaying to invisible final states using data at

$\mathit E_{{\mathrm {cm}}}$ = 7 and 8 TeV. See their Figs. 10, 11 for limits on the cross section times branching ratio for

${\mathit m}_{{{\mathit H}^{0}}}$ =

$100 - 400$ GeV.

⁷ AAD 2013AG search for

${{\mathit H}^{0}}$ production in the decay mode

${{\mathit H}^{0}}$

$\rightarrow$

${{\mathit X}^{0}}{{\mathit X}^{0}}$ , where

${{\mathit X}^{0}}$ is a long-lived particle which decays to

${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit X}^{'0}}$ , in 1.9 fb

${}^{-1}$ of

${{\mathit p}}{{\mathit p}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 7 for limits on cross section times branching ratio.

⁸ AAD 2013AT search for

${{\mathit H}^{0}}$ production in the decay

${{\mathit H}^{0}}$

$\rightarrow$

${{\mathit X}^{0}}{{\mathit X}^{0}}$ , where

${{\mathit X}^{0}}$ eventually decays to clusters of collimated

${{\mathit e}^{+}}{{\mathit e}^{-}}$ pairs, in 2.04 fb

${}^{-1}$ of

${{\mathit p}}{{\mathit p}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 3 for limits on cross section times branching ratio.

⁹ CHATRCHYAN 2013BJ search for

${{\mathit H}^{0}}$ production in the decay chain

${{\mathit H}^{0}}$

$\rightarrow$

${{\mathit X}^{0}}{{\mathit X}^{0}}$ ,

${{\mathit X}^{0}}$

$\rightarrow$

${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit X}^{'0}}$ 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.

¹⁰ AAD 2012AQ search for

${{\mathit H}^{0}}$ production in the decay mode

${{\mathit H}^{0}}$

$\rightarrow$

${{\mathit X}^{0}}{{\mathit X}^{0}}$ , where

${{\mathit X}^{0}}$ is a long-lived particle which decays mainly to

${{\mathit b}}{{\overline{\mathit b}}}$ in the muon detector, in 1.94 fb

${}^{-1}$ of

${{\mathit p}}{{\mathit p}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 7 TeV. See their Fig. 3 for limits on cross section times branching ratio for

${\mathit m}_{{{\mathit H}^{0}}}$ = 120, 140 GeV,

${\mathit m}_{{{\mathit X}^{0}}}$ = 20, 40 GeV in the

${{\mathit c}}{{\mathit \tau}}$ range of

$0.5 - 35$ m.

¹¹ AALTONEN 2012AB search for

${{\mathit H}^{0}}$ production in the decay

${{\mathit H}^{0}}$

$\rightarrow$

${{\mathit X}^{0}}{{\mathit X}^{0}}$ , where

${{\mathit X}^{0}}$ eventually decays to clusters of collimated

${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ pairs, in 5.1 fb

${}^{-1}$ of

${{\mathit p}}{{\overline{\mathit p}}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. Cross section limits are provided for a benchmark MSSM model incorporating the parameters given in Table VI.

¹² AALTONEN 2012U search for

${{\mathit H}^{0}}$ production in the decay mode

${{\mathit H}^{0}}$

$\rightarrow$

${{\mathit X}^{0}}{{\mathit X}^{0}}$ , where

${{\mathit X}^{0}}$ is a long-lived particle with

$\mathit c{{\mathit \tau}}$

$\approx{}$ 1 cm which decays mainly to

${{\mathit b}}{{\overline{\mathit b}}}$ , in 3.2 fb

${}^{-1}$ of

${{\mathit p}}{{\overline{\mathit p}}}$ collisions at

$\mathit E_{{\mathrm {cm}}}$ = 1.96 TeV. See their Figs. 9 and 10 for limits on cross section times branching ratio for

${\mathit m}_{{{\mathit H}^{0}}}$ = (

$130 - 170$ ) GeV,

${\mathit m}_{{{\mathit X}^{0}}}$ = 20, 40 GeV.

¹³ ABBIENDI 2010 search for

${{\mathit e}^{+}}$

${{\mathit e}^{-}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}$ with

${{\mathit H}^{0}}$ decaying invisibly. The limit assumes SM production cross section and B(

${{\mathit H}^{0}}$

$\rightarrow$ invisible) = 1.

¹⁴ ABBIENDI 2007 search for

${{\mathit e}^{+}}$

${{\mathit e}^{-}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}$ with

${{\mathit Z}}$

$\rightarrow$

${{\mathit q}}{{\overline{\mathit q}}}$ and

${{\mathit H}^{0}}$ decaying to invisible final states. The

${{\mathit H}^{0}}$ width is varied between 1 GeV and 3 TeV. A limit

$\sigma \cdot{}$ B(

${{\mathit H}^{0}}$

$\rightarrow$ invisible)

$<$ (

$0.07 - 0.57$ ) pb (95

$\%$ CL) is obtained at

$\mathit E_{{\mathrm {cm}}}$ = 206 GeV for

${\mathit m}_{{{\mathit H}^{0}}}$ =

$60 - 114~$ GeV.

¹⁵ Search for

${{\mathit e}^{+}}$

${{\mathit e}^{-}}$

$\rightarrow$

${{\mathit H}^{0}}{{\mathit Z}}$ with

${{\mathit H}^{0}}$ decaying invisibly. The limit assumes SM production cross section and B(

${{\mathit H}^{0}}$

$\rightarrow$ invisible) = 1.

¹⁶ ACCIARRI 2000M search for

${{\mathit e}^{+}}$

${{\mathit e}^{-}}$

$\rightarrow$

${{\mathit Z}}{{\mathit H}^{0}}$ with

${{\mathit H}^{0}}$ decaying invisibly at

$\mathit E_{{\mathrm {cm}}}=183 - 189~$ GeV. The limit assumes SM production cross section and B(

${{\mathit H}^{0}}$

$\rightarrow$ invisible)=1. See their Fig.

$~$ 6 for limits for smaller branching ratios.

References:

AABOUD

2019AI

PL B793 499

Search for invisible Higgs boson decays in vector boson fusion at

$\sqrt{s} = 13$ TeV with the ATLAS detector

AAD

2015BH

EPJ C75 299

Search for New Phenomena in Final States with an Energetic Jet and Large Missing Transverse Momentum in

${{\mathit p}}{{\mathit p}}$ Collisions at

$\sqrt {s }$ = 8 TeV with the ATLAS Detector

Also

EPJ C75 408 (errat.)

Erratum to AAD 2015BH. Search for New Phenomena in Final States with an Energetic Jet and Large Missing Transverse Momentum in

${{\mathit p}}{{\mathit p}}$ Collisions at

$\sqrt {s }$ = 8 TeV with the ATLAS Detector

AAD

2015BD

EPJ C75 337

Search for Invisible Decays of the Higgs Boson Produced in Association with a Hadronically Decaying Vector Boson in

${{\mathit p}}{{\mathit p}}$ Collisions at

$\sqrt {s }$ = 8 TeV with the ATLAS Detector

AAD

2014O

PRL 112 201802

Search for Invisible Decays of a Higgs Boson Produced in Association with a

${{\mathit Z}}$ Boson in ATLAS

AAD

2014BA

JHEP 1411 088

Search for Long-Lived Neutral Particles Decaying into Lepton Jets in Proton-Proton Collisions at

$\sqrt {s }$ = 8 TeV with the ATLAS Detector

CHATRCHYAN

2014B

EPJ C74 2980

Search for Invisible Decays of Higgs Bosons in the Vector Boson Fusion and Associated

${{\mathit Z}}{{\mathit H}}$ Production Modes

AAD

2013AG

PL B721 32

Search for Displaced Muonic Lepton Jets from Light Higgs Boson Decay in Proton

$−$ Proton Collisions at

$\sqrt {s }$ = 7 TeV with the ATLAS Detector

AAD

2013AT

NJP 15 043009

Search for

${{\mathit W}}{{\mathit H}}$ Production with a Light Higgs Boson Decaying to Prompt Electron-Jets in Proton

$−$ Proton Collisions at

$\sqrt {s }$ = 7 TeV with the ATLAS Detector

CHATRCHYAN

2013BJ

PL B726 564

Search for a Non-Standard-Model Higgs Boson Decaying to a Pair of New Light Bosons in Four-Muon Final States

AAD

2012AQ

PRL 108 251801

Search for a Light Higgs Boson Decaying to Long-Lived Weakly Interacting Particles in Proton

$−$ Proton Collisions at

$\sqrt {s }$ = 7 TeV with the ATLAS Detector

AALTONEN

2012U

PR D85 012007

Search for Heavy Metastable Particles Decaying to Jet Pairs in

${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at

$\sqrt {s }$ = 1.96 TeV

AALTONEN

2012AB

PR D85 092001

Search for Anomalous Production of Multiple Leptons in Association with

${{\mathit W}}$ and

${{\mathit Z}}$ Bosons at CDF

ABBIENDI

2010

PL B682 381

Search for Invisibly Decaying Higgs Bosons in

${{\mathit e}^{+}}$

${{\mathit e}^{-}}$

$\rightarrow$

${{\mathit Z}^{0}}{{\mathit h}^{0}}$ Production at

$\sqrt {s }$ =

$183 - 209$ GeV

ABBIENDI

2007

EPJ C49 457

Search for Invisibly Decaying Higgs Bosons with Large Decay Width using the OPAL Detector at LEP

ACHARD

2005

PL B609 35

Search for an Invisibly-Decaying Higgs Boson at LEP

ABDALLAH

2004B

EPJ C32 475

Searches for invisibly Decaying Higgs Bosons with the DELPHI Detector at LEP

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

BARATE

2001C

PL B499 53

Searches for Neutral Higgs Bosons in

${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at

$\mathit E_{{\mathrm {cm}}}$ from 192 to 202 GeV

ACCIARRI

2000M

PL B485 85

Search for an Invisibly Decaying Higgs Boson in

${{\mathit e}^{+}}$

${{\mathit e}^{-}}$ Collisions at

$\sqrt {s }$ = 183-189 GeV

MASS LIMITS FOR NEUTRAL HIGGS BOSONS IN EXTENDED HIGGS MODELS

Mass Limits for H0{{\mathit H}^{0}} Decaying to Invisible Final States INSPIRE search

Mass Limits for ${{\mathit H}^{0}}$ Decaying to Invisible Final States INSPIRE search