Naslov
Underlying Event measurements in pp collisions at sqrt(s) = 0.9 and 7 TeV with the ALICE experiment at the LHC

Autori
Abelev, B. ; ... ; Antičić, Tome ; ... ; Gotovac, Sven ; ... ; Mudnić, Eugen ; ... ; Šuša, Tatjana ; ... ; Vicković, Linda ; ... ; Zynovyev, M.

Izvornik
The Journal of high energy physics (1126-6708) (2012), 7; 116-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
ALICE; LHC; CERN; pp; 0.9 TeV; 7 TeV; Hadron-Hadron Scattering

Sažetak
We present measurements of Underlying Event observables in pp collisions at sqrt(s)=0.9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum pT, LT in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different pT thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2–3 between the lower and higher collision energies, depending on the track pT threshold considered. Data are compared to Pythia 6.4, Pythia 8.1 and Phojet. On average, all models considered underestimate the multiplicity and summed pT in the Transverse region by about 10–30%.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
The ALICE Collaboration

POVEZANOST RADA