First Measurement of the Underlying Event Activity at the LHC with $$\sqrt{s} = 0.9$$ TeV

Journal Article · Sat Nov 06 00:00:00 EDT 2010 · European Physical Journal. C, Particles and Fields

DOI:https://doi.org/10.1140/epjc/s10052-010-1453-9· OSTI ID:1155706

Khachatryan, Vardan ^[1]

---

1. Yerevan Physics Inst. (Armenia)

A measurement of the underlying activity in scattering processes with transverse momentum scale in the GeV region is performed in proton-proton collisions at sqrt(s) = 0.9 TeV, using data collected by the CMS experiment at the LHC. Charged hadron production is studied with reference to the direction of a leading object, either a charged particle or a set of charged particles forming a jet. Predictions of several QCD-inspired models as implemented in PYTHIA are compared, after full detector simulation, to the data. The models generally predict too little production of charged hadrons with pseudorapidity eta < 2, p_T > 0.5 GeV/c, and azimuthal direction transverse to that of the leading object.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: CMS Collaboration
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1155706
• Report Number(s): FERMILAB-PUB-10-726-CMS; arXiv eprint number arXiv:1006.2083
• Journal Information: European Physical Journal. C, Particles and Fields, Vol. 70, Issue 3; ISSN 1434-6044
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS