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Abstract A measurement of the dijet production cross section is reported based on proton–proton collision data collected in 2016 at$$\sqrt{s}=13\,\text {Te}\hspace{-.08em}\text {V} $$ $\sqrt{s}=13\mathrm{Te}V$by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of up to 36.3$$\,\text {fb}^{-1}$$ ${\mathrm{fb}}^{-1}$. Jets are reconstructed with the anti-$$k_{\textrm{T}} $$ $k_{\text{T}}$algorithm for distance parameters of$$R=0.4$$ $R=0.4$and 0.8. Cross sections are measured double-differentially (2D) as a function of the largest absolute rapidity$$|y |_{\text {max}} $$ ${\left|y\right|}_{\max }$of the two jets with the highest transverse momenta$$p_{\textrm{T}}$$ $p_{\text{T}}$and their invariant mass$$m_{1,2} $$ $m_{1,2}$, and triple-differentially (3D) as a function of the rapidity separation$$y^{*} $$ $y^{\ast }$, the total boost$$y_{\text {b}} $$ $y_b$, and either$$m_{1,2} $$ $m_{1,2}$or the average$$p_{\textrm{T}}$$ $p_{\text{T}}$of the two jets. The cross sections are unfolded to correct for detector effects and are compared with fixed-order calculations derived at next-to-next-to-leading order in perturbative quantum chromodynamics. The impact of the measurements on the parton distribution functions and the strong coupling constant at the mass of the$${\text {Z}} $$ $Z$boson is investigated, yielding a value of$$\alpha _\textrm{S} (m_{{\text {Z}}}) =0.1179\pm 0.0019$$ ${\alpha }_{\text{S}}\left(m_Z\right)=0.1179\pm 0.0019$. 

Abstract The strange quark content of the proton is probed through the measurement of the production cross section for a W boson and a charm (c) quark in proton–proton collisions at a center-of-mass energy of 13$$\,\text {Te}\hspace{-.08em}\text {V}$$ $\text{Te}\text{V}$. The analysis uses a data sample corresponding to a total integrated luminosity of 138$$\,\text {fb}^{-1}$$ ${\text{fb}}^{-1}$collected with the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm jets are tagged using the presence of a muon or a secondary vertex inside the jet. The$$\hbox {W}+\hbox {c}$$ $\text{W}+\text{c}$production cross section and the cross section ratio$$R_\textrm{c}^{\pm }= \sigma ({\hbox {W}}^{+}+\bar{\text {c}})/\sigma (\hbox {W}^{-}+{\textrm{c}})$$ $R_{\text{c}}^{\pm }=\sigma ({\text{W}}^{+}+\overline{\text{c}})/\sigma ({\text{W}}^{-}+\text{c})$are measured inclusively and differentially as functions of the transverse momentum and the pseudorapidity of the lepton originating from the W boson decay. The precision of the measurements is improved with respect to previous studies, reaching 1% in$$R_\textrm{c}^{\pm }= 0.950 \pm 0.005\,\text {(stat)} \pm 0.010 \,\text {(syst)} $$ $R_{\text{c}}^{\pm }=0.950\pm 0.005\text{(stat)}\pm 0.010\text{(syst)}$. The measurements are compared with theoretical predictions up to next-to-next-to-leading order in perturbative quantum chromodynamics.