CMS-SMP-22-006

CMS-SMP-22-006 ; CERN-EP-2023-203
Observation of WW$\gamma $ production and search for H$ \gamma $ production in proton-proton collisions at $ \sqrt{s}= $ 13 TeV
CMS Collaboration
8 October 2023
Phys. Rev. Lett. 132 (2024) 121901
Abstract: The observation of WW$\gamma $ production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138 fb$ ^{-1} $ is presented. The observed (expected) significance is 5.6 (4.7) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for WW$\gamma $ is 6.0 $ \pm $ 0.8 (stat) $ \pm $ 0.7 (syst) $ \pm $ 0.6 (modeling) fb, in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks.
Links: e-print arXiv:2310.05164 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; Physics Briefing ; CADI line (restricted) ;

Figures & Tables	Summary	References	CMS Publications

Figures
png pdf	Figure 1: Representative Feynman diagrams for the WW$\gamma $ process at LO, from left to right: ISR, TGC, QGC, and H$ \gamma $ associated production.
png pdf	Figure 1-a: Representative Feynman diagrams for the WW$\gamma $ process at LO, from left to right: ISR, TGC, QGC, and H$ \gamma $ associated production.
png pdf	Figure 1-b: Representative Feynman diagrams for the WW$\gamma $ process at LO, from left to right: ISR, TGC, QGC, and H$ \gamma $ associated production.
png pdf	Figure 1-c: Representative Feynman diagrams for the WW$\gamma $ process at LO, from left to right: ISR, TGC, QGC, and H$ \gamma $ associated production.
png pdf	Figure 1-d: Representative Feynman diagrams for the WW$\gamma $ process at LO, from left to right: ISR, TGC, QGC, and H$ \gamma $ associated production.
png pdf	Figure 2: The distributions of the invariant mass of the dilepton-photon system (left) and the transverse mass of the WW system (right) after the signal region selection before the fit to the data. The black points with error bars represent the data and their statistical uncertainties, whereas the shaded band represents the Monte Carlo statistical uncertainties.
png pdf	Figure 2-a: The distribution of the invariant mass of the dilepton-photon system after the signal region selection before the fit to the data. The black points with error bars represent the data and their statistical uncertainties, whereas the shaded band represents the Monte Carlo statistical uncertainties.
png pdf	Figure 2-b: The distribution of the transverse mass of the WW system after the signal region selection before the fit to the data. The black points with error bars represent the data and their statistical uncertainties, whereas the shaded band represents the Monte Carlo statistical uncertainties.
png pdf	Figure 3: The unrolled two-dimensional $ m_{\mathrm{T}}^{\mathrm{W}\mathrm{W}} $ - $ m_{\ell\ell\gamma} $ distributions in category 0 jet (left) and $ \geq $1 jet (right) after the fit to data. The data are compared with the sum of the signal and expected background. The black points with error bars represent the data and their statistical uncertainties, whereas the hatched bands represent the total uncertainties in the predictions.
png pdf	Figure 3-a: The unrolled two-dimensional $ m_{\mathrm{T}}^{\mathrm{W}\mathrm{W}} $ - $ m_{\ell\ell\gamma} $ distribution in category 0 jet after the fit to data. The data are compared with the sum of the signal and expected background. The black points with error bars represent the data and their statistical uncertainties, whereas the hatched bands represent the total uncertainties in the predictions.
png pdf	Figure 3-b: The unrolled two-dimensional $ m_{\mathrm{T}}^{\mathrm{W}\mathrm{W}} $ - $ m_{\ell\ell\gamma} $ distribution in category $ \geq $1 jet after the fit to data. The data are compared with the sum of the signal and expected background. The black points with error bars represent the data and their statistical uncertainties, whereas the hatched bands represent the total uncertainties in the predictions.

Tables
png pdf	Table 1: The number of events in data and prediction after the fit to data in the SR, SSWW$\gamma $ CR and Top$ \gamma $ CR. The uncertainties include both statistical and systematic contributions.
png pdf	Table 2: Upper limits on the cross section and derived limits in terms of Yukawa coupling at 95% CL for H$ \gamma $ production initiated by light quarks.

Summary

In summary, this letter reports the first observation of WW$\gamma $ production in proton-proton collisions. The measurement uses a data set collected by the CMS experiment at the LHC in 2016--2018 at a center-of-mass energy of 13 TeV, with an integrated luminosity of 138 fb$ ^{-1} $. The measured fiducial cross section for WW$\gamma $ production is 6.0 $ \pm $ 1.2 fb, in agreement with the prediction at next-to-leading order in quantum chromodynamics. A search for the associated production of the Higgs boson and a photon is also performed using the Higgs boson decay to W$^{+}$W$^{-}$. A set of limits at 95% confidence level on the Higgs boson couplings to light quarks is reported.

References
1	CMS Collaboration	Observation of the production of three massive gauge bosons at $ \sqrt {s} = $ 13 TeV	PRL 125 (2020) 151802	CMS-SMP-19-014 2006.11191
2	ATLAS Collaboration	Observation of WWW production in pp collisions at $ \sqrt s = $ 13 TeV with the ATLAS detector	PRL 129 (2022) 061803	2201.13045
3	ATLAS Collaboration	Evidence of W$\gamma\gamma$ production in pp collisions at $ \sqrt {s} = $ 8 TeV and limits on anomalous quartic gauge couplings with the ATLAS detector	PRL 115 (2015) 031802	1503.03243
4	ATLAS Collaboration	Measurements of $ Z\gamma $ and $ Z\gamma\gamma $ production in pp collisions at $ \sqrt{s}= $ 8 TeV with the ATLAS detector	PRD 93 (2016) 112002	1604.05232
5	CMS Collaboration	Measurements of the pp $ \to W\gamma\gamma $ and pp $ \to Z\gamma\gamma $ cross sections and limits on anomalous quartic gauge couplings at $ \sqrt{s}= $ 8 TeV	JHEP 10 (2017) 072	CMS-SMP-15-008 1704.00366
6	CMS Collaboration	Measurements of the pp $ \to W\gamma\gamma $ and pp $ \to Z\gamma\gamma $ cross sections at $ \sqrt{\mathrm{s}} = $ 13 TeV and limits on anomalous quartic gauge couplings	JHEP 10 (2021) 174	CMS-SMP-19-013 2105.12780
7	CMS Collaboration	Search for $ WW \gamma $ and $ WZ \gamma $ production and constraints on anomalous quartic gauge couplings in pp collisions at $ \sqrt s = $ 8 TeV	PRD 90 (2014) 032008	CMS-SMP-13-009 1404.4619
8	ATLAS Collaboration	Study of $ WW\gamma $ and $ WZ\gamma $ production in pp collisions at $ \sqrt{s} = $ 8 TeV and search for anomalous quartic gauge couplings with the ATLAS experiment	EPJC 77 (2017) 646	1707.05597
9	H. Khanpour, S. Khatibi, and M. Mohammadi-Najafabadi	Probing Higgs boson couplings in H${+} \gamma $ production at the LHC	PLB 773 (2017) 462	1702.05753
10	J. A. Aguilar-Saavedra, J. M. Cano, and J. M. No	More light on Higgs flavor at the LHC: Higgs boson couplings to light quarks through $ h $+$ \gamma $ production	PRD 103 (2021) 095023	2008.12538
11	A. Falkowski et al.	Light quark Yukawas in triboson final states	JHEP 04 (2021) 023	2011.09551
12	W. H. Furry	A symmetry theorem in the positron theory	PR 51 (1937) 125
13	Y. Zhou	Probing anomalous couplings of the Higgs boson to weak bosons and fermions with precision calculations	PhD Thesis, Johns Hopkins University, CERN-THESIS-2019-007, 2019 link
14	J. Davis et al.	Constraining anomalous Higgs boson couplings to virtual photons	PRD 105 (2022) 096027	2109.13363
15	Y. Zhou	Constraining the Higgs boson coupling to light quarks in the $ \mathrm{H} \rightarrow \mathrm{Z} \mathrm{Z} $ final states	PRD 93 (2016) 013019	1505.06369
16	LHC Higgs Cross Section Working Group	Handbook of LHC Higgs cross sections: 4. Deciphering the nature of the Higgs sector	CERN Report CERN-2017-002-M, 2016 link	1610.07922
17	CMS Collaboration	Search for Higgs boson decay to a charm quark-antiquark pair in proton-proton collisions at $ \sqrt{s} = $ 13 TeV	PRL 131 (2023) 061801	CMS-HIG-21-008 2205.05550
18	ATLAS Collaboration	Direct constraint on the Higgs-charm coupling from a search for Higgs boson decays into charm quarks with the ATLAS detector	EPJC 82 (2022) 717	2201.11428
19	J. Duarte-Campderros, G. Perez, M. Schlaffer, and A. Soffer	Probing the Higgs--strange quark coupling at $ \textrm{e}^{+}\textrm{e}^{-} $ colliders using light-jet flavor tagging	PRD 101 (2020) 115005	1811.09636
20	ATLAS Collaboration	Search for exclusive Higgs and $ Z $ boson decays to $ \phi\gamma $ and $ \rho\gamma $ with the ATLAS detector	JHEP 07 (2018) 127	1712.02758
21	J.-W. Zhu et al.	WW$\gamma$ production at hadron colliders with NLO QCD+EW corrections and parton shower effects	JPG 47 (2020) 055006	2005.10707
22	CMS Collaboration	HEPData record for this analysis	link
23	CMS Collaboration	Particle-flow reconstruction and global event description with the CMS detector	JINST 12 (2017) P10003	CMS-PRF-14-001 1706.04965
24	CMS Collaboration	The CMS experiment at the CERN LHC	JINST 3 (2008) S08004
25	CMS Collaboration	Measurement of electroweak WZ boson production and search for new physics in WZ + two jets events in pp collisions at $ \sqrt{s} = $ 13 TeV	PLB 795 (2019) 281	CMS-SMP-18-001 1901.04060
26	CMS Collaboration	Electron and photon reconstruction and identification with the CMS experiment at the CERN LHC	JINST 16 (2021) P05014	CMS-EGM-17-001 2012.06888
27	CMS Collaboration	Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at $ \sqrt{s}= $ 13 TeV	JINST 13 (2018) P06015	CMS-MUO-16-001 1804.04528
28	M. Cacciari, G. P. Salam, and G. Soyez	The anti-$ k_{\mathrm{T}} $ jet clustering algorithm	JHEP 04 (2008) 063	0802.1189
29	M. Cacciari, G. P. Salam, and G. Soyez	FastJet user manual	EPJC 72 (2012) 1896	1111.6097
30	M. Cacciari and G. P. Salam	Pileup subtraction using jet areas	PLB 659 (2008) 119	0707.1378
31	E. Bols et al.	Jet flavour classification using DeepJet	JINST 15 (2020) P12012	2008.10519
32	CMS Collaboration	Performance of missing transverse momentum reconstruction in proton-proton collisions at $ \sqrt{s} = $ 13 TeV using the CMS detector	JINST 14 (2019) P07004	CMS-JME-17-001 1903.06078
33	A. Alloul, B. Fuks, and V. Sanz	Phenomenology of the Higgs effective Lagrangian via FEYNRULES	JHEP 04 (2014) 110	1310.5150
34	Particle Data Group , P. A. Zyla et al.	Review of particle physics	Prog. Theor. Exp. Phys. 2020 (2020) 083C01
35	J. Alwall et al.	The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations	JHEP 07 (2014) 079	1405.0301
36	Y. Gao et al.	Spin determination of single-produced resonances at hadron colliders	PRD 81 (2010) 075022	1001.3396
37	S. Bolognesi et al.	Spin and parity of a single-produced resonance at the LHC	PRD 86 (2012) 095031	1208.4018
38	I. Anderson et al.	Constraining Anomalous HVV Interactions at Proton and Lepton Colliders	PRD 89 (2014) 035007	1309.4819
39	A. V. Gritsan, R. Röntsch, M. Schulze, and M. Xiao	Constraining anomalous Higgs boson couplings to the heavy flavor fermions using matrix element techniques	PRD 94 (2016) 055023	1606.03107
40	T. Sjöstrand et al.	An introduction to PYTHIA 8.2	Comput. Phys. Commun. 191 (2015) 159	1410.3012
41	GEANT4 Collaboration	GEANT 4---a simulation toolkit	NIM A 506 (2003) 250
42	CMS Collaboration	Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements	EPJC 80 (2020) 4	CMS-GEN-17-001 1903.12179
43	P. Nason	A new method for combining NLO QCD with shower Monte Carlo algorithms	JHEP 11 (2004) 040	hep-ph/0409146
44	S. Frixione, P. Nason, and C. Oleari	Matching NLO QCD computations with parton shower simulations: the POWHEG method	JHEP 11 (2007) 070	0709.2092
45	S. Alioli, P. Nason, C. Oleari, and E. Re	A general framework for implementing NLO calculations in shower monte carlo programs: the POWHEG BOX	JHEP 06 (2010) 043	1002.2581
46	S. Alioli et al.	Jet pair production in POWHEG	JHEP 04 (2011) 081	1012.3380
47	S. Alioli, P. Nason, C. Oleari, and E. Re	NLO Higgs boson production via gluon fusion matched with shower in POWHEG	JHEP 04 (2009) 002	0812.0578
48	E. Bagnaschi, G. Degrassi, P. Slavich, and A. Vicini	Higgs production via gluon fusion in the POWHEG approach in the SM and in the MSSM	JHEP 02 (2012) 088	1111.2854
49	CMS Collaboration	Measurement of the W$ \gamma $ production cross section in proton-proton collisions at $ \sqrt {s} = $ 13 TeV and constraints on effective field theory coefficients	PRL 126 (2021) 252002	CMS-SMP-19-002 2102.02283
50	CMS Collaboration	Measurement of the cross section for electroweak production of a Z boson, a photon and two jets in proton-proton collisions at $ \sqrt{\mathrm{s}} = $ 13 TeV and constraints on anomalous quartic couplings	JHEP 06 (2020) 076	CMS-SMP-18-007 2002.09902
51	E. Gabrielli, B. Mele, F. Piccinini, and R. Pittau	Asking for an extra photon in Higgs production at the LHC and beyond	JHEP 07 (2016) 003	1601.03635
52	CMS Collaboration	Performance of the CMS Level-1 trigger in proton-proton collisions at $ \sqrt{s} = $ 13 TeV	JINST 15 (2020) P10017	CMS-TRG-17-001 2006.10165
53	CMS Collaboration	The CMS trigger system	JINST 12 (2017) P01020	CMS-TRG-12-001 1609.02366
54	M. Dittmar and H. Dreiner	How to find a Higgs boson with a mass between 155 and 180 GeV at the LHC	PRD 55 (1997) 167	hep-ph/9608317
55	J. Butterworth et al.	PDF4LHC recommendations for LHC Run II	JPG 43 (2016) 023001	1510.03865
56	L. A. Harland-Lang, A. D. Martin, P. Motylinski, and R. S. Thorne	Parton distributions in the LHC era: MMHT 2014 PDFs	EPJC 75 (2015) 204	1412.3989
57	NNPDF Collaboration	Parton distributions for the LHC Run II	JHEP 04 (2015) 040	1410.8849
58	S. Dulat et al.	New parton distribution functions from a global analysis of quantum chromodynamics	PRD 93 (2016) 033006	1506.07443
59	CMS Collaboration	Precision luminosity measurement in proton-proton collisions at $ \sqrt{s} = $ 13 TeV in 2015 and 2016 at CMS	EPJC 81 (2021) 800	CMS-LUM-17-003 2104.01927
60	CMS Collaboration	CMS luminosity measurement for the 2017 data-taking period at $ \sqrt{s} = $ 13 TeV	CMS Physics Analysis Summary, 2018 CMS-PAS-LUM-17-004	CMS-PAS-LUM-17-004
61	CMS Collaboration	CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV	CMS Physics Analysis Summary, 2019 CMS-PAS-LUM-18-002	CMS-PAS-LUM-18-002
62	M. Duehrssen	Study of Higgs bosons in the WW final state and development of a fast calorimeter simulation for the ATLAS experiment	PhD thesis, Freiburg University, CERN-THESIS-2010-061, 2009 link
63	ATLAS and CMS Collaborations, and LHC Higgs Combination Group	Procedure for the LHC Higgs boson search combination in Summer 2011	CMS Physics Analysis Note CMS-NOTE-2011-005, ATL-PHYS-PUB-2011-11, 2011
64	F. Yu	Phenomenology of enhanced light quark Yukawa couplings and the $ W^\pm h $ charge asymmetry	JHEP 02 (2017) 083	1609.06592