Since the initial data taking of the CERN LHC, the CMS experiment has undergone substantial upgrades and improvements. This paper discusses the CMS detector as it is configured for the third data-taking period of the CERN LHC, Run 3, which started in 2022. The entire silicon pixel tracking detector was replaced. A new powering system for the superconducting solenoid was installed. The electronics of the hadron calorimeter was upgraded. All the muon electronic systems were upgraded, and new muon detector stations were added, including a gas electron multiplier detector. The precision proton spectrometer was upgraded. The dedicated luminosity detectors and the beam loss monitor were refurbished. Substantial improvements to the trigger, data acquisition, software, and computing systems were also implemented, including a new hybrid CPU/GPU farm for the high-level trigger.

Event shapes for Au + Au collisions at 11.4 GeV/c per nucleon were studied over nearly the full solid angle with the E877 apparatus. The analysis was performed by Fourier expansion of azimuthal distributions of the transverse energy ($E_T$) measured in different pseudorapidity intervals. For semicentral collisions a pronounced event anisotropy is identified with a clear forward-backward anticorrelation. In the forward pseudorapidity interval up to 9% of the $E_T$ is in a directed component. The signal decreases for peripheral and very central collisions.

A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at $${\sqrt{s}=13\,\text {Te}\hspace{-.08em}\text {V}}$$s = 13 Te V by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 $$\,\text {fb}^{-1}$$fb - 1 . The 95% confidence level upper limit set on the branching fraction of the 125 $$\,\text {Ge}\hspace{-.08em}\text {V}$$Ge V Higgs boson to invisible particles, $${\mathcal {B}({\textrm{H}} \rightarrow \text {inv})}$$B ( H → inv ) , is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous $${\mathcal {B}({\textrm{H}} \rightarrow \text {inv})}$$B ( H → inv ) searches carried out at $${\sqrt{s}=7}$$s = 7 , 8, and 13 $$\,\text {Te}\hspace{-.08em}\text {V}$$Te V in complementary production modes. The combined upper limit at 95% confidence level on $${\mathcal {B}({\textrm{H}} \rightarrow \text {inv})}$$B ( H → inv ) is 0.15 (0.08 expected).