Study of the underlying event at forward rapidity in pp collisions at sqrt(s) = 0.9, 2.76, and 7 TeV

CMS Collaboration;Quertenmont, Loïc;Basegmez, Suzan;Bruno, Giacomo;Bethani, Agni;et.al.
(2013) Journal of High Energy Physics — Vol. 1304, p. 72 (2013)

Files

13022394.pdf
  • Open Access
  • Adobe PDF
  • 456.28 KB

Details

Authors
  • CMS Collaboration
    Author
  • Author
  • Basegmez, SuzanUCLouvain
    Author
  • Author
  • Castello, RobertoUCLouvain
    Author
  • Ceard, LudivineUCLouvain
    Author
  • Author
  • Du Pree, TristanUCLouvain
    Author
  • Favart, DenisUCLouvain
    Author
  • Forthomme, LaurentUCLouvain
    Author
  • Author
  • Hollar, JonathanUCLouvain
    Author
  • Author
  • Liao, JunhuiUCLouvain
    Author
  • Militaru, OtiliaUCLouvain
    Author
  • Nuttens, ClaudeUCLouvain
    Author
  • Pagano, DavideUCLouvain
    Author
  • Pin, ArnaudUCLouvain
    Author
  • Piotrzkowski, KrzysztofUCLouvain
    Author
  • Vizan Garcia, Jesús ManuelUCLouvain
    Author
  • Selvaggi, MicheleUCLouvain
    Author
  • Popov, AndreyUCLouvain
    Author
  • Bethani, Agniorcid-logoUCLouvain
    Author
  • et. al.
Show more
Abstract
The underlying event activity in proton-proton collisions at forward pseudo-rapidity (−6.6 < η < −5.2) is studied with the CMS detector at the LHC, using a novel observable: the ratio of the forward energy density, dE/dη, for events with a charged-particle jet produced at central pseudorapidity (|η jet| < 2) to the forward energy density for inclusive events. This forward energy density ratio is measured as a function of the central jet transverse momentum, p T, at three different pp centre-of-mass energies ( TeX , 2.76, and 7 TeV). In addition, the TeX evolution of the forward energy density is studied in inclusive events and in events with a central jet. The results are compared to those of Monte Carlo event generators for pp collisions and are discussed in terms of the underlying event. Whereas the dependence of the forward energy density ratio on jet p T at each TeX separately can be well reproduced by some models, all models fail to simultaneously describe the increase of the forward energy density with TeX in both inclusive events and in events with a central jet.
Affiliations

Citations

CMS Collaboration, Quertenmont, L., Basegmez, S., Bruno, G., Castello, R., Ceard, L., Delaere, C., Du Pree, T., Favart, D., Forthomme, L., Giammanco, A., Hollar, J., Lemaitre, V., Liao, J., Militaru, O., Nuttens, C., Pagano, D., Pin, A., Piotrzkowski, K., et al. (2013). Study of the underlying event at forward rapidity in pp collisions at sqrt(s) = 0.9, 2.76, and 7 TeV. Journal of High Energy Physics, 1304, 72. https://doi.org/10.1007/JHEP04(2013)072 (Original work published 2013)