Measurement of the energy density as a function of pseudorapidity in proton-proton collisions at $$\sqrt{s} =13\,\text {TeV} $$ s = 13 TeV

• Main Authors: Sirunyan, A. M (Author), Tumasyan, A. (Author), Adam, W. (Author), Ambrogi, F. (Author), Asilar, E. (Author), Bergauer, T. (Author), Brandstetter, J. (Author), Dragicevic, M. (Author), Erö, J. (Author), Del Valle, A. E (Author), Flechl, M. (Author), Frühwirth, R. (Author), Ghete, V. M (Author), Hrubec, J. (Author), Jeitler, M. (Author), Krammer, N. (Author), Krätschmer, I. (Author), Liko, D. (Author), Madlener, T. (Author), Mikulec, I. (Author)
• Format: Article
• Language: English
• Published: Springer Berlin Heidelberg, 2021-09-20T17:29:02Z.
• Subjects: Article
• Online Access: Get fulltext

 Abstract A measurement of the energy density in proton-proton collisions at a centre-of-mass energy of $$\sqrt{s} =13$$ s = 13 $$\,\text {TeV}$$ TeV is presented. The data have been recorded with the CMS experiment at the LHC during low luminosity operations in 2015. The energy density is studied as a function of pseudorapidity in the ranges $$-\,6.6<\eta <-\,5.2$$ - 6.6 < η < - 5.2 and $$3.15<|\eta |<5.20$$ 3.15 < | η | < 5.20 . The results are compared with the predictions of several models. All the models considered suggest a different shape of the pseudorapidity dependence compared to that observed in the data. A comparison with LHC proton-proton collision data at $$\sqrt{s} =0.9$$ s = 0.9 and $$7\,\text {TeV} $$ 7 TeV confirms the compatibility of the data with the hypothesis of limiting fragmentation.