Measurements of the $$\mathrm{t}\overline{\mathrm{t}}$$ t t ¯ production cross section in lepton+jets final states in pp collisions at 8 $$\,\text {TeV}$$ TeV and ratio of 8 to 7 $$\,\text {TeV}$$ TeV cross sections
European physical journal. C, Particles and fields