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The flux of cosmic ray muons at the Earth’s surface exhibits seasonal variations due to changes in the temperature of the atmosphere affecting the production and decay of mesons in the upper atmosphere. Using 1473 live days of data collected by the NuMI Off-axis ${\nu }_e$ Appearance (NOvA) Near Detector during 2018–2022, we studied the seasonal pattern in the multiple-muon event rate. The data confirm an anticorrelation between the multiple-muon event rate and effective atmospheric temperature, consistent across all the years of data. Previous analyses from MINOS and NOvA saw a similar anticorrelation but did not include an explanation. We find that this anticorrelation is driven by altitude–geometry effects as the average muon production height changes with the season. This has been studied with a CORSIKA cosmic ray simulation package by varying atmospheric parameters, and provides an explanation to a longstanding discrepancy between the seasonal phases of single and multiple-muon events. 

This Letter reports measurements of muon-neutrino disappearance and electron-neutrino appearance and the corresponding antineutrino processes between the two NOvA detectors in the NuMI neutrino beam. These measurements use a dataset with double the neutrino mode beam exposure that was previously analyzed, along with improved simulation and analysis techniques. A joint fit to these samples in the three-flavor paradigm results in the most precise single-experiment constraint on the atmospheric neutrino mass splitting, $\mathrm{\Delta }{m}_{32}^2=2.431_{-0.034}^{+0.036}(-2.479_{-0.036}^{+0.036})\times {10}^{-3}{\mathrm{eV}}^2$ if the mass ordering is normal (inverted). In both orderings, a region close to maximal mixing with ${\sin }^2{\theta }_{23}=0.55_{-0.06}^{+0.02}$ is preferred. The NOvA data show a mild preference for the normal mass ordering with a Bayes factor of 2.4 (corresponding to 70% of the posterior probability), indicating that the normal ordering is 2.4 times more probable than the inverted ordering. When incorporating a 2D $\mathrm{\Delta }{m}_{32}^2-{\sin }^{2}2{\theta }_{13}$ constraint based on Daya Bay data, this preference strengthens to a Bayes factor of 6.6 (87%). 

A new technique is developed to identify dielectrons ( $e^{+}{e}^{-}$ ) with Lorentz boost ${\gamma }_{\mathrm{L}}>20$ that produce one single merged cluster in the electromagnetic calorimeter of the CMS detector. The identification uses two multivariate models: one for the case where both electron tracks are reconstructed, and another where only one of the tracks is reconstructed. The efficiency is determined using proton-proton collision data collected at a center-of-mass energy of 13 TeV. Boosted $J/\psi$ mesons decaying into $e^{+}{e}^{-}$ pairs are used to estimate the efficiency of the model with two tracks, yielding an overall efficiency of 80%. The $Z\to {\mu }^{+}{\mu }^{-}\gamma$ events, where the photon converts into a collimated dielectron, are used for the model with a single track, yielding an efficiency of about 60%. A dedicated energy correction for dielectron candidates is also developed using $B^{\pm }\to J/\psi K^{\pm }\to e^{+}{e}^{-}{K}^{\pm }$ data. 

A search for Higgs boson ( $H$ ) production in association with two vector bosons ( $V=W$ , $Z$ ) via vector-boson scattering (VBS) is presented using proton-proton collision data collected at $\sqrt{s}=13\mathrm{TeV}$ by the CMS experiment, corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$ . Events containing two forward jets consistent with VBS, a large-radius jet from the decay of a boosted $H$ to a pair of $b$ quarks, and zero, one, or two charged leptons coming from $V$ decays are selected. The process is excluded at 95% confidence level for observed (expected) values of the $VVHH$ coupling modifier ${\kappa }_{2V}$ outside the interval $0.40<{\kappa }_{2V}<1.60$ ( $0.34<{\kappa }_{2V}<1.66$ ), assuming standard model values for all other couplings, thus establishing a novel probe of the $VVHH$ interaction. Constraints are also set on the individual ${\kappa }_{2W}$ and ${\kappa }_{2Z}$ coupling modifiers and on the allowed region in the ${\kappa }_{2W}\text{−}{\kappa }_{2Z}$ plane. 

Evidence of the production of two $Z$ bosons and a photon in proton-proton collisions is reported for the first time in CMS. The analysis uses data collected by the CMS experiment between 2016 and 2018 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$ . Evidence for the process $pp\to ZZ\gamma \to 4\ell \gamma$ ( $\ell =e$ , $\mu$ ), with an observed (expected) significance of 3.7 (3.1) standard deviations in a fiducial region defined by $p_{\mathrm{T}}^{\gamma }>20\mathrm{GeV}$ , $\left|{\eta }^{\gamma }\right|<2.4$ , $\mathrm{\Delta }R(\ell ,\gamma )>0.5$ , $m_Z$ between 60 and 120 GeV, and the invariant mass of either of the two $Z$ bosons combined with the photon ( $m_{Z_{\gamma }}$ ) larger than 100 GeV, is reported. The measured (predicted) fiducial cross section is ${60}_{-22}^{+27}\mathrm{ab}$ ( $47.56\pm 0.04\mathrm{ab}$ ). Additionally, the inclusive production of $pp\to 4\ell \gamma$ is studied by removing the $m_{Z_{\gamma }}$ requirement to include final state radiation where one $Z$ boson decays to $2\ell \gamma$ , yielding an observed (expected) significance of 5.0 (4.2) standard deviations and a measured (predicted) fiducial cross section of ${156}_{-35}^{+39}\mathrm{ab}$ ( $99.97\pm 0.09\mathrm{ab}$ ). 

The existence of a new spin-zero particle with a mass below the electroweak scale is predicted by several theoretical models. Searches for resonant production of photon pairs at the LHC are able to probe these models. We present a search for a narrow resonance produced through gluon fusion that decays into a pair of photons with an invariant mass between 10 and 70 GeV, using a proton-proton collision dataset from the CMS experiment. This dataset, corresponding to an integrated luminosity of $54.4{\mathrm{fb}}^{-1}$ , was recorded in 2018 at a center-of-mass energy of 13 TeV using a newly introduced diphoton trigger that enabled exploration of the low-mass diphoton spectrum. No significant excess above the expected background is observed. Upper limits are set on the product of the gluon fusion production cross section and the branching fraction of the diphoton decay of a narrow resonance. An interpretation of these limits within an effective field theory framework for axionlike particles is also provided. 

A search is performed for a new resonance $X$ decaying into a Higgs boson and a new scalar boson $Y$ ( $HY$ ) including the case where $Y$ is assumed to be a second Higgs boson ( $HH$ ), using proton-proton collision data collected at $\sqrt{s}=13\mathrm{TeV}$ , corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$ . This study performs a comprehensive exploitation of the $bbZZ$ events, encompassing the following decay topologies. One $H$ candidate is identified through its decay into a bottom quark-antiquark pair, while the other $H$ or the $Y$ candidate is selected through its decay into a pair of $Z$ bosons. One $Z$ boson is required to decay leptonically and the other, to decay into a pair of quarks or neutrinos. Events of interest are categorized based on the Lorentz boosts of the hadronically decaying $H$ and $Z$ bosons. Machine-learning-based discriminants, together with the reconstructed resonance mass, are employed across the different categories to separate signal from backgrounds, and their corresponding distributions are included in a simultaneous fit. No significant deviations from the standard model predictions are observed. Upper limits at the 95% confidence level are set on the $HY$ and $HH$ production cross sections. For $HY$ production, the upper limit on the cross section of the process $pp\to X\to HY\to bbZZ$ ranges from 500 to 5 fb, with the most stringent constraints achieved for high-mass $X$ resonances and $Y$ masses near the threshold for decay into a pair of massive vector bosons. This is comparable to the sensitivity achieved in other analyses, which focus on $H$ decays to $\gamma \gamma$ or $\tau \tau$ and $Y$ decays into a pair of bottom quarks or massive vector bosons. For resonant $HH$ production, the upper limit on the cross section of $pp\to X\to HH$ production is 1 pb for a high-mass resonance. 

A<sc>bstract</sc> A search for Higgs boson (H) production at high transverse momentum (p_T) in the WW decay channel is presented. The analysis uses proton-proton collisions at$$ \sqrt{s}=13 $$ $\sqrt{s}=13$ TeV recorded by the CMS experiment in 2016–2018, corresponding to an integrated luminosity of 138 fb⁻¹. The visible decay products of the Higgs boson are reconstructed as a single large-radius jet with one isolated lepton or none (1ℓand 0ℓ, respectively;ℓ= e,μ). The H-candidate jets are identified using an advanced transformer-based algorithm and are calibrated with the Lund jet plane reweighting technique. The 1ℓchannel is further split into gluon fusion, vector boson fusion, and associated production with hadronically decaying vector boson categories, while the 0ℓchannel considers all production processes inclusively. The measured cross section times the H→WW branching fraction relative to the standard model expectation is$$ \mu =-{0.19}_{-0.46}^{+0.48} $$ $\mu =-{0.19}_{-0.46}^{+0.48}$ , indicating no evidence of a signal above the background. This measurement represents the first dedicated study of highly Lorentz-boosted H→WW decays, complementing earlier searches for high-p_THiggs boson in other decay channels. 

We present the measurement of ${\pi }^{+}$ -argon inelastic cross sections using the ProtoDUNE single-phase liquid argon time projection chamber in the incident ${\pi }^{+}$ kinetic energy range of 500–800 MeV in multiple exclusive channels (absorption, charge exchange, and the remaining inelastic interactions). The results of this analysis are important inputs to simulations of liquid argon neutrino experiments such as the Deep Underground Neutrino Experiment and the Short Baseline Neutrino program at Fermi National Accelerator Laboratory. They will be employed to improve the modeling of final state interactions within neutrino event generators used by these experiments, as well as the modeling of ${\pi }^{+}$ -argon secondary interactions within the liquid argon. This is the first measurement of ${\pi }^{+}$ -argon absorption at this kinetic energy range as well as the first ever measurement of ${\pi }^{+}$ -argon charge exchange. 

A search for the pair production of heavy spin- $1/2$ or spin- $3/2$ resonances ( $t^{*}$ ) in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$ is presented. Data collected with the CMS detector at the CERN LHC from 2016 to 2018 corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$ are used. The analysis targets benchmark signal scenarios where one $t^{*}$ decays into a top quark ( $t$ ) and a photon ( $\gamma$ ), and the other into a $t$ quark and a gluon ( $g$ ), i.e., $pp\to t^{*}\overline{t^{*}}\to tt\gamma g$ . All-hadronic final states from the $t$ pair decay chain are selected using jet substructure techniques. The signal is probed as a function of the $t^{*}$ candidate mass, which is reconstructed using the photon and a top quark candidate jet. No significant deviation from the background-only hypothesis is found. Observed (expected) upper limits on the signal cross section at 95% confidence level are set, excluding masses of spin- $1/2$ $t^{*}$ particles below 930 (930) GeV and spin- $3/2$ $t^{*}$ particles below 1330 (1390) GeV. This analysis marks the first search for heavy resonances in the $t\overline{t}\gamma g$ channel. Exploiting the high-energy photon to reduce the backgrounds, this search achieves sensitivity competitive with $pp\to t^{*}\overline{t^{*}}\to t\overline{t}gg$ searches for spin- $1/2$ $t^{*}$ despite the small expected $t^{*}\to t\gamma$ branching fraction.