First measurement of the top quark pair production cross section in proton-proton collisions at $\sqrt{s}$ = 13.6 TeV

The first measurement of the top quark pair (t¯t) production cross section
in proton-proton collisions at √
s = 13.6 TeV is presented. Data recorded with the CMS
detector at the CERN LHC in Summer 2022, corresponding to an integrated luminosity
of 1.21 fb−1
, are analyzed. Events are selected with one or two charged leptons (electrons
or muons) and additional jets. A maximum likelihood fit is performed in event categories
defined by the number and flavors of the leptons, the number of jets, and the number of
jets identified as originating from b quarks. An inclusive t¯t production cross section of
881 ± 23 (stat + syst) ± 20 (lumi) pb is measured, in agreement with the standard model
prediction of 924+32
−40 pb.