Higgs Exotic Decay

Goal of the group

Group Contacts

In case of questions or problems, please report them to all the conveners.

• Theory: Brian Shuve (Harvey Mudd College), Matthias Konig (University of Zurich)
• ATLAS: Verena Martinez (University of Massachusetts)
• CMS: Georgia Karapostoli (University of California Riverside)
• LHCb: Lorenzo Sestini (INFN Padova)

Don't forget to remove 'SPAMNOT' in the email addresses before sending.

Meetings

Meeting	Date	Location	Link to Indico	Link to minute
17th LHCHXS WG Workshop	9-11 November 2020	Vidyo	Indico
16th LHCHXS WG Workshop	16-18 October 2019	CERN	Indico
Exotic Higgs Decays Workshop	7-8 November 2016	SLAC, CA, US	Indico	Minute
Exotic Higgs Decays Workshop	21-22 May 2015	Fermilab, Illinois, US and Vidyo	Indico	Minute
Exotic Higgs Decays Kick-off Meeting	26-27 March 2015	Vidyo-Only	Indico	Minute

Yellow Report 4

Here would be a summary of the Higgs Exotic Chapters of the YR4 ([link to arxiv):

Exclusive mesonic and flavour-violating Higgs boson decays

Rare exclusive decays of the SM-like Higgs boson to mesonic final states provide a unique window onto light quark Yukawa couplings. We discuss the SM predictions for the branching ratio for Higgs boson decays into a meson plus a photon and for Higgs boson decay to a meson plus a massive gauge boson . Additionally we summarize the impact of different frameworks for physics beyond the SM on these exclusive branching ratios following by a discussion about the prospects for their detection at the LHC.

Recommendations for searches for exotic Higgs boson decays

In Run 2 of the LHC, the programmatic search for exotic Higgs boson decays will increasingly become an important topic of study. To help guide this experimental program, in this section we provide a set of recommendations for searches for the production of exotic particles in the decays of the Higgs boson.

The recommendation will cover the following domains:

• A signature-based search program for exotic decays

• Presentation of results

• Production cross-sections

• Signal event generation

• Mass ranges

Partonic distributions for the prompt decay topology h → XX → 2Y 2Y ′

In this section we study the decay topology where the Higgs boson decays to two exotic particles of the same mass, each of which then undergoes a prompt two-body decay to visible SM particles Y, Y ′: h → XX → 2Y 2Y ′. This decay topology is naturally realized in many well-motivated BSM frameworks. In particular, extensions of the Higgs sector by an additional, possibly complex, singlet scalar can naturally have Higgs boson decays to (pseudo-)scalars as one of their leading signatures. These (pseudo-)scalars decay mainly to fermions, with preference for heavy flavour. Signals of this class of models, SM+S and 2HDM+S. The NMSSM is one of the best-studied examples of this type of extended Higgs sector. It has a large portion of parameter space where an approximate R-symmetry yields a SM-like Higgs boson with appreciable branching ratio into a pair of light pseudo- scalars a. Other motivations for singlet-extended Higgs sectors include models of first-order electroweak phase transitions and thermal dark matter . In composite Higgs models, a symmetry-protected light pseudo-scalar in the spectrum may be fermiophobic, with dominant decays to gluon or photon pairs, thus yielding the exotic decay modes h → aa → 4g,2γ2g,4γ. Another well-studied extension of the SM is a Higgsed dark U(1) that kinetically mixes with SM hypercharge, in which case the Higgs boson decay h → ZDZD → 2f2f′ yields final states weighted by gauge couplings, rather than Yukawa couplings, giving relatively leptophilic signatures All these exotic decays have very similar parton- level kinematics

Prospects for prompt decays with MET :h → 2γ + E/T test case

In this study, we devise a search strategy for the exotic decay of the 125 GeV Higgs boson in the $\gamma\gamma+MET$ final state. The studied final state comes in two different topologies: resonant and non-resonant. In the resonant case, the Higgs decays into two scalars, one being undetected and the other decaying resonantly into two photons. The non-resonant case, based on low scale SUSY breaking models, the Higgs decays into two neutralinos, each subsequently decaying into a photon and a gravitino. We estimate the sensitivity of these searches using a DELPHES detector simulation, and targeting $100$ fb$^{-1}$ of $\sqrt{s}=14$ TeV $pp$ data from the LHC.

Many plots for this search can be found here: https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHWGExoticDecayYR4ExtraMaterials

Longlived particles from Higgs boson decays

Long-lived particles (LLPs), specifically meta-stable particles with proper lifetimes cτ μm, arise in a large variety of BSM scenarios. Such particles, once produced at the LHC or other colliders, can decay within the detector volume with measurable displacement from the interaction point. For experimental searches, this represents both a challenge and an opportunity. On the one hand, the ATLAS and CMS detectors were not specifically optimized for displaced decays, which can make triggering and reconstruction challenging. On the other hand, events with displaced decays are spectacular and relatively background-free. This makes LLP searches enticing discovery avenues for new physics, especially in light of null results from prompt BSM searches at the LHC Run 1.

Generating MC samples for displaced objects ( Madgraph implementation )

The hXX-HF scenario can be realized by repurposing the SM + dark vector + dark Higgs MadGraph model of available at http://insti.physics.sunysb.edu/~curtin/hahm_mg.html. In this model, X is identified with the dominantly singlet scalar state hs, with mX corresponding to the model parameter MHSinput. The singlet hs decays to SM fermions via its mixing with the SM-like Higgs h, which is controlled by the model parameter kap. This MadGraph model includes the couplings between the Higgs and SM gauge bosons, including the gluons via an effective operator. X therefore inherits the same couplings, and decays like X → V*V* can also be generated.

For a given Br(h → XX), ΓX = 1/(cτX) and mX, the procedure for generating h → XX → SM events is the following:

1. Switch off dark photon effects (by setting the epsilon and mZDinput parameters to, say, 10e-09 and 1000e+00 respectively.)

2. Set the parameter MHSinput to the desired mX .

3. Event generation will depend on how LLPs are handled, specifically whether X is decayed in MadGraph or e.g. in Pythia. In the former case, one could generate the processes

p p > hs hs, hs > b b ̃

p p > hs hs, hs > ta+ ta-

p p > hs hs, hs > ta+ ta-, hs > b b ̃

separately (for the most important b ̄b and τ+τ− final states), then manually displace the decays. In the latter case, X can be left undecayed in MadGraph. The lifetime can then be written to the LHE file before running through Pythia. Another possibility is to produce events with the X decay implemented directly in Pythia. In that case the lifetime can be written to the SLHA file.

4. Each sample can then be rescaled to the desired σh ×Br(h → XX)×BR(XX → fff f ). Here σh is the inclusive Higgs boson production cross section, and BR(X → f f ) can be computed for a SM-like Higgs boson of mass mX using HDECAY 6.42. This method ensures that important NLO QCD and threshold effects are handled accurately, which is not guaranteed if using LO branching fractions generated internally by Madgraph or Pythia. Higher-order differential effects in Higgs boson production can be taken into account by reweighing events using Higgs boson pT spectra according to the recommendations of Secs. IV.6.3 and IV.6.4 of yellow report 4

Benchmark models

Signature	Motivation	Parameter calculations	MC implementation	Contact
H → ALPs	1708.00443, see attached slides for exp signatures, nice benchmark for H(125)→aa (ss) → 4y/2j2y	ALP BRs for 1 benchmark point: g(fermions)=1; g(gauge bosons)=1/(4 pi)^2, BR figure		Andrea Thamm
H(125)→aa (ss) →XXYY	1312.4992	Br(a(s)→XX) for plots from the paper, outside of the quarkonia regions plotdata.zip		Stefania Gori, Yiming Zhong
H(125)→aa (ss) →XXYY	1802.02156	BR.tgz. Calculations provide Br(a->xx) values for multiple tan(beta) values and cover also the quarkonia regions. Please read the README.txt to know how to use them.		Ulrich Haisch
H(125)→hh	1601.07880, 1501.02234,slides	see the quoted papers	available, contact the authors	Tania Robens, Tim Stefaniak
H(125)→h1h2	1908.08554, slides, slides	see the quoted paper	available, contact the authors	Tania Robens, Tim Stefaniak, Jonas Wittbrodt
H(125)→hh	EWPT: 1911.10210, 1911.10206	Br(S->ff) have been calculated using HDECAY, see the attached plot: s_Brs_1911.10210.pdf		paper authors
H(125)→2Zd→4 lep	1412.0018	Table2 of 1412.0018	hahm_mg	Jessie Shelton, Stefania Gori, David Curtin, Rouven Essig
H(125)→2Hd→4Ad→8 lep	Hto8lepChannel_Stolarski	Table2 of 1412.0018	hahm_mg	Daniel Stolarski
H(125)→aa (ss) →XXYY/invis	mixture of visible & invisible (DM) decays

Parameter calculations

• Higgs rare decays to mesons + photon
  • Most up-to-date calculations for decays to light mesons: 1505.03870v3
  • Most up-to-date calculations for decays to heavy quarkonia (J/Psi, Upsilon) using heavy-quark effective theory: 1907.06473v2

Results

CMS Higgs Exotic Decay Results

CADI #	Signature	Title	Mass range	Luminosity and Dataset	Trigger	Results	arXiv	Journal
PAS-HIG-19-012	H(125) -> Z+ρ/ϕ	Search for decays of the H(125) into a Z boson and a ρ or ϕ meson	H(125)	137/ fb at 13 TeV	Standard single-lepton: IsoMu24, Ele27WPTight (2016), IsoMu27, Ele35WPTight (2017), IsoMu24, Ele32WPTight (2018)	Upper limits on the Higgs boson branching fractions into Zρ and Zϕ are determined to be 1.21-1.89% and 0.36-0.58%, respectively, where the ranges reflect the considered polarization scenarios; these values are 860-1350 and 860-1380 times larger than the respective standard model expectations.	2007.05122	Submitted to JHEP
PAS-HIG-19-007	h->XX/ZX->4l	Search for a low-mass dilepton resonance in Higgs boson decays to four-lepton final states	4<m(X)<60 GeV	137/ fb at 13 TeV		Upper limits are set on model-independent cross sections and Higgs boson decay BRs. Additionally, limits on dark photon and axion-like particle models are reported.	no arXiv yet
PAS-HIG-18-025	H->J/ψ J/ψ or H->Υ(nS) Υ(nS)	Search for Higgs and Z boson decays to J/ψ or Υ pairs	H(125)	37.5/ fb at 13 TeV	Dedicated triggers in 2017: HLT_Dimuon0_Jpsi3p5_Muon2, HLT_Trimuon5_3p5_2_Upsilon_Muon	Upper limits on the branching fractions. In the J/ψ pair final state the limits are 1.8×10−3 for the Higgs boson, respectively, while in the combined Υ(nS) pair final states the limits are 1.4×10−3	1905.10408	PLB 797 (2019) 134811
HIG-18-024	H->aa->μμττ (boosted)	Search for a light a1 boson boson in the boosted μμττ final state	m(a)<2*m(b): 3.6 <m(a)< 21 GeV	35.9/ fb at 13 TeV	Iso(Tk)Mu24	Limits on BR for H→aa→μμττ, down to 1.5 (2.0) × 10−4 for mH= 125 (300) GeV. Model-dependent limits on BR(H→aa) are set within 2HDM+s models, with the most stringent results obtained for Type-III models.	2005.08694	Accepted for publication in JHEP
HIG-18-017	h->μτ, h->eτ	Search for lepton flavour violating decays of a neutral heavy Higgs boson to μτ and eτ	h mass: 200-900 GeV	35.9/ fb at 13 TeV	singleMu for μτ, singleEle for eτ(h), electron-muon trigger for eτ(μ)	Upper limits on the production cross section multiplied by the branching fraction vary from 51.9 (57.4) fb to 1.6 (2.1) fb for the μτ and from 94.1 (91.6) fb to 2.3 (2.3) fb for the eτ	1911.10267	JHEP 03 (2020) 103
HIG-18-011	h->a1a1->2b2mu	Search for an exotic decay of the Higgs boson to two a1 bosons in final state with two muons and two b quarks	20 < m(a) < 62.5 GeV	35.9/ fb at 13 TeV	doubleMu (17 & 8 GeV) OR Iso(Tk)Mu24 OR Iso(Tk)Mu22_eta2p1	The limits on the branching fraction are (1-6)×10−4. Compared with the similar analysis in Run I, the limits are improved by more than a factor of two	1812.06359	Phys. Lett. B 795 (2019) 398
PAS-HIG-18-006	H→a1a1→4τ/2μ2τ	Search for light pseudoscalar boson pairs in final states with two muons and two nearby tracks	4 < m(a) < 15 GeV	35.9/ fb at 13 TeV	doubleMu (17 & 8 GeV) + same-sign + DZ	With no evidence for a signal, the observed upper limit on the product of the inclusive signal cross section and the branching fraction, relative to the SM H production cross section, ranges from 0.022 at ma1= 9 GeV to 0.23 at ma1= 4 GeV and reaches 0.16 at ma1=15 GeV.	1907.07235	Phys. Lett. B 800 (2019) 135087
HIG-18-003	h->a1a1->4mu	Search for pair production of new light bosons decaying into muons	light boson masses from 0.25 to 8.5 GeV	35.9/ fb at 13 TeV	doubleMu: HLT_TrkMu15_DoubleTrkMu5NoFiltersNoVtx	Result interpreted in the context of the NMSSM and a dark supersymmetry model that allows for nonnegligible light boson lifetimes.	1812.00380	Phys. Lett. B 796 (2019) 131
HIG-17-029	H->aa->μμττ	Search for light pseudoscalars in the final state of two muons and two τ leptons	m(a) between 15.0 and 62.5 GeV	35.9/ fb at 13 TeV	doubleMu (17 & 8 GeV)	Upper limits are set on the branching fraction of the Higgs boson to two light pseudoscalar bosons in different types of 2HDM+s	1805.04865	JHEP 11 (2018) 018
PAS-HIG-17-023	VBF h->invisible	Search for invisible decays of the Higgs boson produced through vector boson fusion	mH=125.09 GeV	35.9/ fb at 13 TeV	MET and HT triggers with 110 or 120 GeV thresholds	Upper limit of 0.24 (0.18) is placed on the invisible branching fraction. This result is also interpreted in the context of Higgs-portal dark matter models. The combined observed (expected) upper limit is 0.19 (0.15).	1809.05937	PLB 793 (2019) 520
HIG-17-001	h->μτ, h->eτ	Search for lepton flavour violating decays of the Higgs boson to μτ and eτ	h(125)	35.9/ fb at 13 TeV	single-mu, single-ele, e+mu triggers	The observed (expected) upper limits on the lepton flavour violating BRs are BR(H→μτ)< 0.25% (0.25%) and BR(H→eτ)< 0.61% (0.37%), at 95% confidence level.	1712.07173	JHEP 06 (2018) 001
HIG-13-010	h->a1a1->4mu	Search for non-SM Higgs decaying to two a1 bosons that decay to muons	2mμ < m(a) < 2mτ and 85 < h<150 GeV	20.7/ fb and 8 TeV	doubleMu (17 & 8 GeV)	No excess is found. Results interpretation in NMSSM and in scenarios containing a hidden sector, including those predicting a nonnegligible light boson lifetime	1506.00424	Phys. Lett. B 752 (2016) 146
HIG-13-030	h->invisible	Search for invisible Higgs decays in the VBF and associated Z production	115-145	up to 19.7/fb and 8 TeV	MET+2 fwd-jets (VBF), dilepton (ZH) and MET+2jet (bbH)	the observed (expected) upper limit on the invisible branching fraction at mH = 125 GeV is found to be 0.58 (0.44) at 95% confidence level	1404.1344	Eur. Phys. J. C 74 (2014) 2980
HIG-14-005	h->muTau and h->mue	Search for lepton-flavour-violating decays of the Higgs boson	0-300	19.7/fb and 8 TeV	singleMu and Mu+electron	The search sensitivity is an order of magnitude better than the existing indirect limits. A slight excess of signal events with a significance of 2.4 standard deviations is observed. The best fit branching fraction is B(H to mu tau) = (0.84 +0.39 -0.37)%. B(H to mu tau) < 1.51% at 95% confidence level is set. Constrain the mu-tau Yukawa couplings to be less than 3.6E-3.	1502.07400	Phys. Lett. B 749 (2015) 337
HIG-14-003	H → (J/ψ)γ	Search for a Higgs boson decaying into gamma* gamma to ll gamma with low dilepton mass in pp collisions at sqrt(s) = 8 TeV	120-150	19.7/fb and 8 TeV	Gamma+Muon and double_gamma	upper limit at 95% CL on the branching fraction of H to(JPsi) gamma for the 125 GeV Higgs boson is set at 1.5E-3	1507.03031	Phys. Lett. B 753 (2016) 341
HIG-14-019	h2->h1h1->4taus	Search for NMSSM h2(125) to h1h1 to 4tau	4-8 GeV	19.7/fb and 8 TeV	doublemu (17 and 8 GeV)	no significant excess in data above standard model background expectations, an upper limit set on the signal production cross section times branching fraction as a functionofthea1(h1) boson mass.The limit ranges from 4.5 pb at ma1 (mh1)=8GeV to 10.3pb at ma1 (mh1) = 5GeV.	1510.06534	10.1007/JHEP01(2016)079
HIG-14-022	H → aa(hh)→ττ ττ	Search for Higgs Decays to New Light Bosons in Boosted Tau Final States	5-15 GeV	19.7/fb and 8 TeV	Single Mu	No excess of events above the Standard Model backgrounds is found, and upper limits are set on the branching ratio BR(H → aa/hh)BR2(a/h → ττ)	(Not available in arXiv)	http://cds.cern.ch/record/2058768?ln=en
HIG-14-025	h->photon+undetected	Search for exotic decays of a Higgs boson into undetectable particles and photons	0-120 GeV	up to 19.4 and 8 TeV	Gamma+MET(for ggH) & single/double lepton (for ZH)	For neutralino masses from 1 to 120 GeV an upper limit in the range of 7 to 13% is obtained	1507.00359	0.1016/j.physletb.2015.12.017
HIG-14-040	H → eτ and H → eμ	Search for LFV Higgs boson decays in the e-tau and e-mu final states at 8 TeV	0-300	19.7 and 8 TeV	e+mu trigger & single electron trigger	set a limit on the branching ratio of B(H → eμ) < 0.036% at 95% confidence level. The limits on B(H → eτ) and B(H → eμ) are subsequently used to constrain the Yeτ and Yeμ Yukawa couplings.	(Not available in arXiv)	http://cds.cern.ch/record/2046190?ln=en
HIG-15-011	H → aa→μμ ττ	Search for the exotic decay of the Higgs boson to two light pseudoscalar bosons with two taus and two muons in the final state at 8 TeV	2-62.5	19.7 and 8 TeV	double muon trigger	Masses of the pseudoscalar boson between 20 and 62.5 GeV are probed, and upper limits between 4 and 15% are set on the branching fraction of the Higgs boson to two light pseudoscalar bosons, under the hypothesis that the pseudoscalar a does not decay to quarks.	(Not available in arXiv)	http://cds.cern.ch/record/2128149?ln=en
HIG-15-011	H → aa→μμ bb;	Search for exotic decays of the Higgs boson to a pair of new light bosons with two muon and two b jets in final states at 8 TeV	25-62.5	19.7 and 8 TeV	double muon trigger	Search for exotic decays of a Higgs boson with mh =125GeV to a pair of new light bosons, a1, where one of the light bosons decays to a pair of muons and the other one decays to a pair of b quarks is reported.A data sample corresponding to an integrated luminosity of 19.7 fb−1 recorded with the CMS detector in 2012 is exploited in μ+μ−bb final states where no statistically significant excess is observed with respect to the standard model back- grounds for different ma1 hypotheses above 25 GeV and below mh/2.	(Not available in arXiv)	http://cds.cern.ch/record/2135985?ln=en

ATLAS Higgs Exotic Decay Results

Channel (date public)	Title	Data set	CDS public	arXiv	Journal
H → aa→ 4b (May 2020)	Search for Higgs boson decays into two new low-mass spin-0 particles in the 4b channel (boosted)	36/fb (2015-2016)	https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2018-47/	arXiv:2005.12236
H → Za(→ jj) (Apr 2020)	Search for Higgs boson decays into a Z boson and a light hadronically decaying resonance	139/fb (2015-2018)	https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2018-37/	https://arxiv.org/abs/2004.01678
H → ss → 4f (March 2020)	Reinterpretation of the ATLAS Search for Displaced Hadronic Jets with the RECAST Framework	10-33/fb	https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PUBNOTES/ATL-PHYS-PUB-2020-007/
H → ss → 4f (Feb 2019)	Search for long-lived neutral particles in pp collisions at that decay into displaced hadronic jets	10-33/fb	https://arxiv.org/abs/1902.03094
H → lepton jets	Search prospects for dark-photons decaying to displaced collimated jets of muons at HL-LHC	3000 /fb	https://cds.cern.ch/record/2654518/files/ATL-PHYS-PUB-2019-002.pdf
H → inv, VBF	Search for invisible Higgs boson decays in vector boson fusion at √s = 13 TeV with the ATLAS detector	36.1/fb (2015-2016)		arXiv:1809.06682
H → φγ / ργ	Search for exclusive Higgs and Z boson decays to φγ and ργ with the ATLAS detector	36.1/fb (2015-2016)		arXiv:1712.02758	JHEP 07 (2018) 127
H → J/ψ γ / ψ(2S) γ / ϒ(nS) γ	Searches for exclusive Higgs and Z boson decays into J/ψ γ, ψ(2S) γ, and ϒ(nS) γ at √s = 13 TeV with the ATLAS detector	36.1/fb (2015-2016)			Phys. Lett. B 786 (2018) 134
H→aa→bbμμ	Search for Higgs boson decays into a pair of light bosons in the bbμμ final state in pp collisions at √s = 13 TeV with the ATLAS detector	36.1/fb (2015-2016)	HIGG-2016-03	arXiv:1807.00539
H → 2a → 4b	Search for the Higgs boson produced in association with a vector boson and decaying into two spin-zero particles in the H → 2a → 4b channel in pp collisions at 13 TeV with the ATLAS detector	36.1/fb (2015-2016)		arXiv:1606.08391
H → γγjj	Search for Higgs boson decays into pairs of light (pseudo)scalar particles in the γγjj final state in pp collisions at 13 TeV with the ATLAS detector	36.1/fb (2015-2016)		arXiv:1803.11145
H → Zd Zd → 4lep	Search for Higgs boson decays to beyond-the-Standard-Model light bosons in four-lepton events with the ATLAS detector at √s=13 TeV	36.1/fb (2015-2016)		arXiv:1802.03388
H → γ+MET	Search for exotic decays of the Higgs boson to at least one photon and missing transverse momentum using 79.8 1/fb of proton-proton collisions collected at √s = 13 TeV with the ATLAS detector	79.8/fb	ATLAS-CONF-2018-019
H → γγ+MET	A search for new phenomena in events with missing transverse momentum and a Higgs boson decaying to two photons at √s = 13 TeV with the ATLAS detector	36.1/fb	ATLAS-CONF-2017-024
H → γγ+MET	A search for new phenomena in events with missing transverse momentum and a Higgs boson decaying to two photons in a 13.3 fb-1 pp collision dataset at √s = 13 TeV with the ATLAS detector	13.3/fb (2015+2016)	ATLAS-CONF-2016-087
h(125) → φγ	Search for Higgs and Z Boson Decays to φγ with the ATLAS Detector	3.2/fb (2015)		arXiv:1607.03400	Phys. Rev. Lett. 117, 111802 (2016)
h(125) → 2a → 4b	Search for the Higgs boson produced in association with a W boson and decaying to four b-quarks via two spin-zero particles in pp collisions at 13 TeV with the ATLAS detector	3.2/fb (2015)		arXiv:1606.08391	Eur. Phys. J. C (2016) 76:605
h(125) → γγ + MET	Search for new phenomena in events with missing transverse momentum and a Higgs boson decaying to two photons in pp collisions at √s = 13 TeV with the ATLAS detecto	3.2/fb (2015)	ATLAS-CONF-2016-011
h → τμ / τe / eμ	Search for lepton-flavour-violating decays of the Higgs and Z bosons with the ATLAS detector	Full 8 TeV		arXiv:1604.07730	Submitted to EPJC
VBF H→ INV	Search for a high-mass Higgs boson decaying to W boson pairs in pp collisions at √s = 8 TeV with the ATLAS detector	Full 8 TeV		arXiv:1508.07869	JHEP01(2016)172
H→γγγγ	Search for new phenomena in events with at least three photons collected in pp collisions at √s = 8 TeV with the ATLAS detector	Full 8 TeV		arXiv:1509.05051	Eur. Phys. J. C (2016) 76:210
LFV H→μτ	Search for lepton-flavor-violating H→μτ decays of the Higgs boson with the ATLAS detector	Full 8 TeV		arXiv:1508.03372	JHEP11(2015)211
H→ γγ + MET	Search for Dark Matter in Events with Missing Transverse Momentum and a Higgs Boson Decaying to Two Photons in pp Collisions with the ATLAS Detector at √s = 8 TeV	full 8 TeV		arXiv:1506.01081	Phys. Rev. Lett. 115, 131801 (2015)
H→hh→4b	Search for Higgs boson pair production in the b b-bar b b-bar final state from pp collisions at √s = 8 TeV with the ATLAS detector	Full 8 TeV		arXiv:1506.00285	Eur. Phys. J. C (2015) 75:412
H→ Z(dark)Zdark	Search for new light gauge bosons in Higgs boson decays to four-lepton final states in pp collisions at √s = 8 TeV with the ATLAS detector at the LHC	Full 8 TeV		arXiv:1505.07645	Phys. Rev. D 92, 092001 (2015)
VH→(had)INV	Search for the invisible decay of the Higgs boson produced in association with a vector boson in pp collisions at √s = 8 TeV	Full 8 TeV		arXiv:1504.04324	Eur. Phys. J. C (2015) 75:337
H/h→aa→μμττ	Search for Higgs bosons decaying to aa in the mu mu tau tau final state in pp collisions at √s = 8 TeV	Full 8 TeV		arXiv:1505.01609	Phys. Rev. D92 (2015) 052002
VBF H→ INV	Search for an Invisibly Decaying Higgs Produced via Weak Boson Fusion	Full 8 TeV	Conf note		ATLAS-CONF-2015-004
H->γ+MET	Search for exotic Higgs-boson decays in events with at least one photon, missing transverse momentum, and two forward jets produced in s√ = 8 TeV pp collisions with the ATLAS detector	Full 8 TeV	Conf note		ATLAS-CONF-2015-001
H→INV (monojet)	Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at sqrt(s) = 8 TeV with the ATLAS detector	Full 8 TeV		arXiv:1502.01518	Eur. Phys. J. C (2015) 75:299
H→Jψγ	Search for Higgs and Z Boson Decays to J/psi gamma and Upsilon(nS) gamma with the ATLAS Detector	Full 8 TeV		arXiv:1501.03276	Phys. Rev. Lett. 114 (2015) 121801
h->long lived particles	Search for pair produced long-lived neutral particles decaying in the ATLAS hadronic calorimeter	Full 8 TeV	Conf note		ATLAS-CONF-2014-041
h->hh->4b	Search for resonant Higgs-pair production in the 4b final state	Full 8 TeV	Conf note		ATLAS-CONF-2014-005
ZH→ (ll)INV	Search for Invisible Decays of a Higgs Boson Produced in Association with a Z boson in ATLAS	7+8 TeV		arXiv:1402.3244	HIGG-2013-03

LHCb Higgs Exotic Decay Results

References

Links

-- ReiTanaka - 2014-12-18

• Hto8lepChannel_Stolarski.pdf: Hto8lepChannel_Stolarski.pdf

• ALP_Brs_Thamm.zip: Brs for ALP benchmark point (1708.00443)

• ALP Brs: blue(ee,mm,tt)(dot,dash,solid)_green(ss,cc,bb)_red(yy)_orange(gg):
  

• Thamm_ALP_Signatures.pdf: ALPs exp signatures