Latest CMS Higgs (125) results
on behalf of the CMS Collaboration

QCD@LHC 2017
20th Lomonosov Conference on Elementary Particle Physics 2021

Outline

Higgs boson mass is the only free parameter (assuming SM): I will show the CMS
results of mass measurements
Look for deviations in H(125) boson properties from the SM predictions
Non-SM like structures in production and decay amplitudes: spin-parity, mixed states…
Rates in different production and decay modes: test of couplings to SM particles
Natural width: can provide an indirect sign for presence of abnormal decay modes

Look for abnormal wrt SM production and decay modes of H(125) boson
In a short talk, I will show only some selected (by me) results

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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Higgs boson mass
Higgs mass – the only free parameter in the Higgs
sector (assuming SM)
all other parameters are set by the known masses ofW and Z bosons, and fermions

Most precise mass measurements channels are:
H → ZZ → 4ℓ and H→ 𝛾𝛾𝛾𝛾
statistical power is very similar
challenge in H→ 𝛾𝛾𝛾𝛾: systematics ~ stat error

Run 1 + 2016 results: 15 Feb 2020, PLB 805 (2020) 135425
125.38 ± 0.14 GeV (~0.1% !)Run 1 + Run 2:
expect precision better than 100 MeV

HL-LHC:statistical uncertainty ~10 MeV
the challenge will be controlling syst. uncertainties
Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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Looking for deviations in SM-like properties

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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Higgs decay modes in SM (green - established)
SM HiggsbbWW

ττccZZ

γγ

Zγ

μμ58%

21%

6.3%

2.9%

2.6%

0.23%

0.15%

0.022%

Remainder: 𝐠𝐠𝐠𝐠, 𝒒𝒒𝒒𝒒, 𝒆𝒆𝒆𝒆9%Latest updates for the well-established decays (>5𝝈𝝈):

𝑯𝑯 → 𝝁𝝁𝝁𝝁

𝑯𝑯 → 𝜸𝜸𝜸𝜸:
𝑯𝑯 → 𝒁𝒁𝒁𝒁:
𝑯𝑯 → 𝑾𝑾𝑾𝑾:
𝑯𝑯 → 𝝉𝝉𝝉𝝉:
𝑯𝑯 → 𝒃𝒃𝒃𝒃:

𝜇𝜇 = 1.12 ± 0.09
12 Mar 2021, arXiv:2103.06956 [Run 2]
𝜇𝜇 = 0.94 ± 0.11
8 Mar 2021, arXiv:2103.04956 [Run 2]
𝜇𝜇fid = 1.05 ± 0.12 4 July 2020, JHEP 03 (2021) 003 [Run 2]
𝜇𝜇 = 0.85 ± 0.12
31 July 2020, HIG-19-010 [Run 2]
𝜇𝜇 = 1.04 ± 0.20

Evidence for 𝑯𝑯 → 𝝁𝝁𝝁𝝁

PRL 121 (2018) 121801 [2016+2017 data]
9 Sep 2020, JHEP 01 (2021) 148 [Run 2]– Significance 3.0– Signal strength 𝜇𝜇 = 1.19 ± 0.42

The observed decays comprise ~90% of the total Higgs widthGuenakh Mitselmakher

20th Lomonosov Conference, 2021

5Established production modes
Intermediate Run 2 combination 9 Jan 2020, HIG-19-005 [mix]••> 5𝜎𝜎> 3𝜎𝜎> 3𝜎𝜎> 3𝜎𝜎> 5𝜎𝜎
Guenakh Mitselmakher

𝐻𝐻 → 𝛾𝛾𝛾𝛾, 𝐻𝐻 → 𝑍𝑍𝑍𝑍, 𝐻𝐻 → 𝑊𝑊𝑊𝑊, 𝐻𝐻 → 𝜏𝜏𝜏𝜏, 𝐻𝐻 → 𝑏𝑏𝑏𝑏, 𝐻𝐻 → 𝜇𝜇𝜇𝜇𝑡𝑡𝑡𝑡𝐻𝐻 (𝐻𝐻 → 𝑊𝑊𝑊𝑊/𝑍𝑍𝑍𝑍/𝜏𝜏𝜏𝜏) → 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙

𝒕𝒕𝒕𝒕𝑯𝑯, 𝑯𝑯 → 𝜸𝜸𝜸𝜸

25 Mar 2020, PRL 125 (2020) 061801 [Run 2]– Significance 6.6– 𝜇𝜇 = 1.13 ± 0.10

𝒕𝒕𝒕𝒕𝑯𝑯, 𝑡𝑡𝑡𝑡𝑡𝑡 (𝐻𝐻 → 𝑊𝑊𝑊𝑊/𝑍𝑍𝑍𝑍/𝜏𝜏𝜏𝜏) → 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙
7 Nov 2020, HIG-19-008 [Run 2]– Significance 4.7– 𝜇𝜇 = 0.92 ± 0.24

20th Lomonosov Conference, 2021

6Fit for couplings modifiers
Event rate for 𝑖𝑖𝑖𝑖 → 𝐻𝐻 → 𝑓𝑓𝑓𝑓:
Fit for six Higgs coupling modifiers: 𝜅𝜅W, 𝜅𝜅Z, 𝜅𝜅t, 𝜅𝜅b, 𝜅𝜅𝜏𝜏, 𝜅𝜅µAssuming:• no “new physics” in loop-driven couplings (𝐻𝐻 → 𝛾𝛾𝛾𝛾, gg→ 𝐻𝐻)• no BSM decays (invisible, not observed)• couplings to the 1st/2nd–gen. quarks and electrons are SM-like(i.e., small and hence having a negligible effect on the fit)

Impressive agreement with SM over three orders ofmagnitude of couplings ! (note: ±5% for ttH coupling)
Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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Are H125 quantum JCP numbers 0++,
as predicted by the SM ?

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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INTRO: Higgs bosonic (V) coupling structure
General Lagrangian for HVV interactions up to dim-5 operators:

𝐿𝐿 = −

𝑎𝑎1 2𝑎𝑎2𝑎𝑎3𝑎𝑎4𝑎𝑎5
𝑚𝑚𝑉𝑉 𝐻𝐻𝑉𝑉𝜇𝜇 𝑉𝑉𝜇𝜇 −𝐻𝐻𝐹𝐹𝜇𝜇𝜇𝜇 𝐹𝐹𝜇𝜇𝜇𝜇 −𝐻𝐻𝐹𝐹𝜇𝜇𝜇𝜇 𝐹𝐹� 𝜇𝜇𝜇𝜇 +𝐻𝐻𝑉𝑉𝜇𝜇 ⊡ 𝑉𝑉𝜇𝜇 +⊡ 𝐻𝐻 𝑉𝑉𝜇𝜇 𝑉𝑉𝜇𝜇2𝑣𝑣
2𝑣𝑣
2𝑣𝑣2𝑣𝑣
2𝑣𝑣

SM dim-3 operator dim-5 operators: loop-induced (very small in SM) or, otherwise, non-renormalizablemagenta factors with 𝑎𝑎𝑖𝑖 /𝑣𝑣 are one of a conventions; they could’ve been written just as 1/Λ𝑖𝑖
In SM: 𝑎𝑎1 = 2 for ZZ, WW 𝒂𝒂𝟐𝟐 term is CP-even. In SM, 𝒂𝒂𝟐𝟐 ~O 10−2 [it is actually the lowest-order term for 𝐻𝐻 → 𝛾𝛾𝛾𝛾]
The term vanishes for 𝛾𝛾𝛾𝛾 𝒂𝒂𝟑𝟑 term is the CP-odd term. In SM, 𝒂𝒂𝟑𝟑 ~O 10−11 [due to CP-violation in the quark sector]
𝒂𝒂𝟒𝟒 term is is yet another CP-even distinct operator. In SM, ~O 10−2
𝒂𝒂𝟓𝟓 term is experimentally indistinguishable from SM in on-shell studies (important for off-shell)
HVV couplings can be probed in HVV decays and VH and VBF production
modes: four-fermion kinematics is sensitive to the HVV coupling structure.
This technique was used to establish π0 parity in 1962: π0  γ*γ*  (ee)(ee)When combining, HZZ and HWW processes,
one has to assume how 𝑎𝑎𝑖𝑖𝑍𝑍𝑍𝑍 and 𝑎𝑎𝑖𝑖𝑊𝑊𝑊𝑊 are related to each otherGuenakh Mitselmakher

20th Lomonosov Conference, 2021

9Higgs bosonic (V) coupling structureℓHZZ4l• On-shell analysis only•

WW and ZZ couplings 𝑎𝑎𝑖𝑖𝑊𝑊𝑊𝑊 and 𝑎𝑎𝑖𝑖𝑍𝑍𝑍𝑍 are related
via custodial and SU(2)xSU(1) symmetries:••••

𝑎𝑎1𝑊𝑊𝑊𝑊 = 𝑎𝑎1𝑍𝑍𝑍𝑍𝑎𝑎2𝑊𝑊𝑊𝑊 = cos2 𝜃𝜃𝑊𝑊 𝑎𝑎2𝑍𝑍𝑍𝑍 + ⋯ (𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛)
𝑎𝑎3𝑊𝑊𝑊𝑊 = cos2 𝜃𝜃𝑊𝑊 𝑎𝑎3𝑍𝑍𝑍𝑍 + ⋯ (𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛)
…

𝑍𝑍𝑍𝑍

ℓ

30 July 2020, HIG-19-009 [Run 2]

𝑞𝑞ℓℓ– red line: SM 0+– blued line:
0–ℓℓ

𝑞𝑞ℓℓ

𝑞𝑞

𝑞𝑞ℓℓℓℓ• Production modes: VBF tag, VH tag, untagged• ME-based discriminants
68% CL:

𝑎𝑎3𝑍𝑍𝑍𝑍 /𝑎𝑎1𝑍𝑍𝑍𝑍 = 0.018+0.066−0.034

𝑎𝑎2𝑍𝑍𝑍𝑍 /𝑎𝑎1𝑍𝑍𝑍𝑍 = −0.004+0.045−0.058

Coupling ratios are extracted from ratios 𝑓𝑓𝑎𝑎𝑎 and 𝑓𝑓𝑎𝑎𝑎 (Approach 2), given in the paper

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

10INTRO: Higgs fermionic (f) coupling structure
General lowest-dim Lagrangian for Higgs-fermion interactions:
𝐿𝐿 = −𝑚𝑚𝑓𝑓𝑣𝑣

𝜓𝜓�𝑓𝑓 𝜅𝜅𝑓𝑓 + 𝑖𝑖 𝑘𝑘�𝑓𝑓 𝛾𝛾5 𝜓𝜓𝑓𝑓 𝐻𝐻𝜅𝜅𝑓𝑓 term is CP-even𝑘𝑘�𝑓𝑓 term is CP-odd

Define mixing angle 𝜙𝜙, where tan𝜙𝜙 =both are tree-level (unlike HVV)

SM:
MSSM:
nMSSM:

Guenakh Mitselmakher••

pure CP-even state:pure CP-odd state:�𝒇𝒇 = 𝟎𝟎; hence, 𝝓𝝓 = 𝟎𝟎
𝜿𝜿𝒇𝒇 = 𝟏𝟏, 𝒌𝒌

𝜙𝜙 = 0°𝜙𝜙 = 90°

� 𝑓𝑓𝑘𝑘𝜅𝜅𝑓𝑓

𝜙𝜙 ≈ 0𝜙𝜙 can be large, but < 27° (due to existing experimental constraints)
20th Lomonosov Conference, 2021

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Higgs fermionic coupling structure: ttH
25 Mar 2020, PRL 125 (2020) 061801 [Run 2]

Final states used:
𝑝𝑝𝑝𝑝 → 𝑡𝑡𝑡𝑡𝑯𝑯 → (𝑗𝑗𝑗𝑗𝑗𝑗)(𝑗𝑗𝑗𝑗𝑗𝑗)(𝜸𝜸𝜸𝜸) [all-hadronic]
𝑝𝑝𝑝𝑝 → 𝑡𝑡𝑡𝑡𝑯𝑯 → 𝑙𝑙𝑣𝑣𝑏𝑏 𝑗𝑗𝑗𝑗𝑗𝑗 𝜸𝜸𝜸𝜸 [semi-leptonic]𝜇𝜇bb

𝜈𝜈

𝛾𝛾𝛾𝛾

Building a ME-based discriminantthat would account fora whole slew of jet mis-measurements(plus missing neutrino in semi-leptonic channel)
is challenging…

Instead, a BDT-based discriminant (D0-) is built using
CP-even and CP-odd MC models, with the following inputs:
kinematics of the first six jets (in pT) and their b-tag scores𝜑𝜑, 𝜂𝜂 -direction of the diphoton system
for semi-leptonic channel: lepton multiplicity, leading lepton kinematics

Pure CP-odd ttH coupling is disfavored at 3.2𝝈𝝈
68% CL: 𝜙𝜙 < 35°
95% CL: 𝜙𝜙 < 55°Guenakh Mitselmakher

20th Lomonosov Conference, 2021

events are S/(S+B) weighted
background is subtracted|fCP| = sin2 𝜙𝜙12

Higgs fermionic coupling structure: H𝝉𝝉𝝉𝝉
Final states used: 𝜏𝜏𝜇𝜇 𝜏𝜏ℎ and 𝜏𝜏ℎ 𝜏𝜏ℎ𝜏𝜏𝜇𝜇 → 𝜇𝜇 ± 𝜈𝜈𝜈𝜈(17%)

𝜏𝜏ℎ → 𝜋𝜋 ± 𝜈𝜈 (12%)→ 𝜌𝜌± 𝜈𝜈 → 𝜋𝜋 ± 𝜋𝜋 0 𝜈𝜈 (26%)→ 𝑎𝑎1± 𝜈𝜈 → 𝜋𝜋 ± 𝜋𝜋 0 𝜋𝜋 0 𝜈𝜈 (10%)→ 𝑎𝑎1± 𝜈𝜈 → 𝜋𝜋 ± 𝜋𝜋 ± 𝜋𝜋 ∓ 𝜈𝜈 (10%)

𝝓𝝓CP angle for
𝐻𝐻 → 𝜏𝜏ℎ 𝜏𝜏ℎ → (𝜌𝜌+ 𝜈𝜈)(𝜌𝜌− 𝜈𝜈) → 𝜋𝜋 + 𝜋𝜋 0 𝜋𝜋 − 𝜋𝜋 0 𝜈𝜈 𝜈𝜈

30 July 2020, HIG-20-006 [Run 2]

Signal (H) vs Bkg BDT enhances the signal VBF
contribution with two forward-backward jets
Building a ME-based discriminants that would accountfor jet mis-measurements and missing neutrinos ispossible, but challenging…
Distributions of angles between planes set by observableparticles from decaying tau leptons (𝝓𝝓CP) are sensitive toCP-admixture phase 𝜙𝜙

Guenakh Mitselmakher

Pure CP-odd ttH coupling is disfavored at 3.2𝝈𝝈
68% CL: 𝜙𝜙 = 4 ± 17°
95% CL: 𝜙𝜙 < 36°

20th Lomonosov Conference, 2021

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Higgs(125) widthGuenakh Mitselmakher

20th Lomonosov Conference, 2021

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Most precise Higgs (125) width measurements (indirect)
1 Jan 2019, PRD 99 (2019) 112003 [Run 1 + 2016 + 2017]

From the ratio of off-shell to on-shell rates using
𝑯𝑯 → 𝒁𝒁𝒁𝒁 → 𝟒𝟒𝟒

𝚪𝚪𝑯𝑯 = 𝟑𝟑. 𝟐𝟐+𝟐𝟐.𝟖𝟖−𝟐𝟐.𝟐𝟐 MeV

25 Mar 2020, PRL 125 (2020) 061801 [2016 dataset]𝚪𝚪𝑯𝑯 = 𝟒𝟒. 𝟎𝟎 +𝟏𝟏.𝟑𝟑−𝟏𝟏.𝟎𝟎 MeV

And assuming:••

SM-like amplitude structure for 𝐻𝐻 → 𝑍𝑍𝑍𝑍
No significant BSM physics in 𝑔𝑔𝑔𝑔 → 𝐻𝐻 up to mH*~1 TeV

From the combination of all on-shell decays
And assuming:• SM-like amplitude structure for Higgs couplings• |κW|, |κZ| ≤ 1 (hard to build a theory violating these conditions)
Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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Non- SM decay/production modesof the H125 boson

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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Search for Charged Lepton Flavor Violation in decays:
𝐇𝐇 → 𝝁𝝁𝝁𝝁, 𝐇𝐇 → 𝒆𝒆𝝉𝝉

17 Mar 2021, HIG-20-009 [Run 2]

Channels used:• μτh, μτe• eτh, eτμVery similar to the “nominal” H → 𝜏𝜏𝜏𝜏analysis, except that μ and e••

are prompt
tend to have larger momenta

BDT is used to separate signal fromnon-Higgs bkg and H → ττB(H → μτ) < 0.15%

B(H → eτ) < 0.22%
Guenakh Mitselmakher

most sensitive final state in
𝐇𝐇 → 𝝁𝝁𝝁𝝁 search: μτh + 2-jet VBF tag
20th Lomonosov Conference, 2021

Limits on off-diagonal
Yukawa couplings Y𝝁𝝁𝝁𝝁17

ss

Higgs production cross-section with decays 𝐇𝐇 → 𝝉𝝉𝝉𝝉23 Jul 2021 arXiv:2107.11486 Sub to PRLCross sections of the Higgs
boson production have beenmeasured in the Higgs decay
channel of two τ leptons.
Fiducial inclusive cross section is426 ± 102 fb, in agreement withthe standard-model.
Differential cross sections asfunctions of the Higgs boson
Observed and expected
Observed and expectedtransverse momentum, the jet
differential fiducial crossdifferential fiducial crossmultiplicity, and transverse
section in bins of pTH
section in bins of Njets
momentum of the leading jet, are inagreement with the SM expectations, with a competitive precision with other final states.

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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Summary• the H125 Higgs looks more and more SM-like••keep looking for small deviations
some measurements already challenge the accuracy of theoretical predictions

Full-Run2 analyses are still to come – stay tuned
Run 3 (2022-2024) – expect to triplicate the integrated luminosity
and CMS is being made an even more capable detector!
More Higgs analyses will be at presently constructed HL LHC (High LuminosityLHC) - new accelerator at CERN.

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

19BACKUP SLIDES

Guenakh Mitselmakher

20th Lomonosov Conference, 2021

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