Measurement of inclusive and differential Higgs boson production cross sections in the diphoton decay channel in proton-proton collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This CMS analysis measures inclusive and differential Higgs production cross sections in the H→γγ channel using 13 TeV pp collisions, emphasizing a fiducial phase space defined by photon isolation and kinematics. It employs a mass-resolution based categorization and a simultaneous likelihood fit to extract signal across multiple bins, with background estimated via discrete profiling. The inclusive fiducial cross section is found to be 84 ± 13 fb, in agreement with the SM prediction of 73 ± 4 fb, and differential results are presented for observables sensitive to production mechanisms and QCD radiation. The study also defines a VBF-enriched fiducial region and several jet-related observables to probe Higgs production dynamics within a robust, detector-resilient framework.

Abstract

Measurements of the inclusive and differential production cross sections for the Higgs boson in the diphoton decay channel are performed using the data set of proton-proton collisions at $\sqrt{s} =$ 13 TeV collected by the CMS experiment at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The cross sections are measured in a fiducial phase space defined by a set of requirements on the isolation and kinematic variables of the photons. Differential cross sections are measured as functions of the kinematic properties of the diphoton system and the event. A subset of the measurements is performed in subregions of the fiducial phase space, where relative contributions of specific Higgs boson production mechanisms are enhanced. The total cross section in the chosen fiducial phase space is measured to be 84 $\pm$ 11 (stat) $\pm$ 7 (syst) fb = 84 $\pm$ 13 fb, to be compared with a theoretical prediction of 73 $\pm$ 4 fb. All measurements are found to be in agreement with the theoretical predictions for the standard model Higgs boson with a mass of 125.09 GeV within the experimental and theoretical uncertainties.

Figures (11)

• Figure 1: Comparison of the decorrelated mass resolution estimator $\sigma_{m}^{D}$ distributions in data and simulation for $Z\to\mathrm{e}^+\mathrm{e}^-$ events where both electrons are reconstructed as photons, passing the selection defined in Section \ref{['sec:selection']}. The impact of the systematic uncertainty in the $\sigma_E/E$ is indicated by the red band. The distributions are shown separately for events with both electrons in the EB (left) and the remainder of the events, i.e., events with at least one photon in the EE (right). Events in the shaded gray region are discarded from the final analysis.
• Figure 2: The diphoton mass spectrum in data (black points), together with the best signal-plus-background fit (red lines), for each $\sigma_{m}^{D}$ category employed for the measurement of the inclusive fiducial cross section, as defined in Section \ref{['sec:categorization']}. The two bands indicate the one and two standard deviation uncertainty in the background component.
• Figure 3: Likelihood scan (black curve) for the fiducial cross section measurement, where the value of the SM Higgs boson mass is profiled in the fit. The measurement is compared to the theoretical prediction (vertical red line), shown with its uncertainty (red hatched area), and it is found in agreement within the uncertainties.
• Figure 4: Measurement of the differential cross section (black points) as functions of $p_{\mathrm{T}}\xspace^{\gamma\gamma}\xspace$, $N_{\text{jet}}\xspace$, $\lvert y^{\gamma\gamma} \rvert\xspace$, and $\lvert \cos(\theta^*) \rvert\xspace$. The error bars indicate $1$ standard deviation uncertainty. The systematic component of the uncertainty is shown by the blue band. The measurements are compared to different simulation programs (histograms) with their uncertainties (hatched areas), all normalized to the same theoretical predictions from Ref. LHCHXSWG:YR4. When the last bin of the distribution is an overflow bin, the normalization of the cross section in that bin is indicated in the figure.
• Figure 5: Measurement of the differential cross section (black points) as functions $p_{\mathrm{T}}\xspace^{j_{\text{1}}}\xspace$, $\lvert y^{j_{\text{1}}} \rvert\xspace$, $\lvert \Delta\phi^{\gamma\gamma,j_{\text{1}}} \rvert\xspace$, and $\lvert \Delta y^{\gamma\gamma,j_{\text{1}}} \rvert\xspace$. The error bars indicate $1$ standard deviation uncertainty. The systematic component of the uncertainty is shown by the blue band. The measurements are compared to different simulation programs (histograms) with their uncertainties (hatched areas), all normalized to the same theoretical predictions from Ref. LHCHXSWG:YR4. When the last bin of the distribution is an overflow bin, the normalization of the cross section in that bin is indicated in the figure.