Three rare decay processes of the Higgs boson to a $\rho$(770)$^0$, $\phi$(1020), or K$^{*}$(892)$^0$ meson and a photon are searched for using $\sqrt{s}$ = 13 TeV proton-proton collision data collected by the CMS experiment at the LHC. Events are selected assuming the mesons decay into a pair of charged pions, a pair of charged kaons, or a charged kaon and pion, respectively. Depending on the Higgs boson production mode, different triggering and reconstruction techniques are adopted. The analyzed data sets correspond to integrated luminosities up to 138 fb$^{-1}$, depending on the reconstructed final state. After combining various data sets and categories, no significant excess above the background expectations is observed. Upper limits at 95% confidence level on the Higgs boson branching fractions into $\rho$(770)$^0$$\gamma$, $\phi$(1020)$\gamma$, and K$^{*}$(892)$^0\gamma$ are determined to be 3.7 $\times$ 10$^{-4}$, 3.0 $\times$ 10$^{-4}$, and 3.0 $\times$ 10$^{-4}$, respectively. In case of the $\rho$(770)$^0$$\gamma$ and $\phi$(1020)$\gamma$ channels, these are the most stringent experimental limits to date.
Expected and observed UL on $\mathcal{B}(H\rightarrow\rho\gamma)$ split by analysis categories and combined. Green and yellow bands correspond to 68\% and 95\% confidence intervals on the expected upper limits.
Expected and observed UL on $\mathcal{B}(H\rightarrow\phi\gamma)$ split by analysis categories and combined. Green and yellow bands correspond to 68\% and 95\% confidence intervals on the expected upper limits.
Expected and observed UL on $\mathcal{B}(H\rightarrow K^{*0}\gamma)$ split by analysis categories and combined. Green and yellow bands correspond to 68\% and 95\% confidence intervals on the expected upper limits.
A combination of the results of several searches for the electroweak production of the supersymmetric partners of standard model bosons, and of charged leptons, is presented. All searches use proton-proton collision data at $\sqrt{s}$ = 13 TeV recorded with the CMS detector at the LHC in 2016-2018. The analyzed data correspond to an integrated luminosity of up to 137 fb$^{-1}$. The results are interpreted in terms of simplified models of supersymmetry. Two new interpretations are added with this combination: a model spectrum with the bino as the lightest supersymmetric particle together with mass-degenerate higgsinos decaying to the bino and a standard model boson, and the compressed-spectrum region of a previously studied model of slepton pair production. Improved analysis techniques are employed to optimize sensitivity for the compressed spectra in the wino and slepton pair production models. The results are consistent with expectations from the standard model. The combination provides a more comprehensive coverage of the model parameter space than the individual searches, extending the exclusion by up to 125 GeV, and also targets some of the intermediate gaps in the mass coverage.
Post-fit distribution of the $M(ll)$ variable for the low-$p_{\mathrm{T}}^{\mathrm{miss}}$ bins in the '2l soft' signal region of the '2/3l soft' analysis.
Post-fit distribution of the $M(ll)$ variable for the medium-$p_{\mathrm{T}}^{\mathrm{miss}}$ bins in the '2l soft' signal region of the '2/3l soft' analysis.
Post-fit distribution of the $M(ll)$ variable for the high-$p_{\mathrm{T}}^{\mathrm{miss}}$ bins in the '2l soft' signal region of the '2/3l soft' analysis.
A search for supersymmetric particles produced in the vector boson fusion topology in proton-proton collisions is presented. The search targets final states with one or zero leptons, large missing transverse momentum, and two jets with a large separation in rapidity. The data sample corresponds to an integrated luminosity of 35.9 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 13 TeV collected in 2016 with the CMS detector at the LHC. The observed dijet invariant mass and lepton-neutrino transverse mass spectra are found to be consistent with the standard model predictions. Upper limits are set on the cross sections for chargino ($\widetilde\chi_1^\pm$) and neutralino ($\widetilde\chi_2^0$) production with two associated jets. For a compressed mass spectrum scenario in which the $\widetilde\chi_1^\pm$ and $\widetilde\chi_2^0$ decays proceed via a light slepton and the mass difference between the lightest neutralino $\widetilde\chi_1^0$ and the mass-degenerate particles $\widetilde\chi_1^\pm$ and $\widetilde\chi_2^0$ is 1 (30) GeV, the most stringent lower limit to date of 112 (215) GeV is set on the mass of these latter two particles.
Selection efficiency on signal for each channel.
The observed $m_{T}$ and $m_{jj}$ distributions in the ejj (upper left), $\mu$~jj (upper right), $\tau_{h}$~jj (lower left), and $0\ell$~jj (lower right) signal regions compared with the post-fit SM background yields from the fit described in the text. The pre-fit background yields and shapes are determined using data-driven methods for the major backgrounds, and based on simulation for the smaller backgrounds. Expected signal distributions are overlaid. The last bin in the $m_{T}$ distributions of the $1\ell$~jj channels include all events with $m_{T} > 210$~GeV. The last bin of the $m_{jj}$ distributions of the $0\ell$~jj channel include all events with $m_{jj} > 3800$~GeV.
The observed $m_{T}$ and $m_{jj}$ distributions in the ejj (upper left), $\mu$~jj (upper right), $\tau_{h}$~jj (lower left), and $0\ell$~jj (lower right) signal regions compared with the post-fit SM background yields from the fit described in the text. The pre-fit background yields and shapes are determined using data-driven methods for the major backgrounds, and based on simulation for the smaller backgrounds. Expected signal distributions are overlaid. The last bin in the $m_{T}$ distributions of the $1\ell$~jj channels include all events with $m_{T} > 210$~GeV. The last bin of the $m_{jj}$ distributions of the $0\ell$~jj channel include all events with $m_{jj} > 3800$~GeV.
Forum