Article

Two-pion Bose-Einstein correlations in pp collisions at sqrt(s)=900 GeV

Physical Review D (Impact Factor: 4.86). 07/2010; 82:052001:1-14. DOI: 10.1103/PhysRevD.82.052001
Source: arXiv

ABSTRACT We report on the measurement of two-pion correlation functions from pp
collisions at sqrt(s)=900 GeV performed by the ALICE experiment at the Large
Hadron Collider. Our analysis shows an increase of the HBT radius with
increasing event multiplicity, in line with other measurements done in
particle- and nuclear collisions. Conversely, the strong decrease of the radius
with increasing transverse momentum, as observed at RHIC and at Tevatron, is
not manifest in our data.

Full-text

Available from: Daniel Felea, Jun 03, 2015
6 Followers
 · 
446 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In high-energy collisions, the spatio-temporal size of the particle production region can be measured using the Bose–Einstein correlations of identical bosons at low relative momentum. The source radii are typically extracted using two-pion correlations, and characterize the system at the last stage of interaction, called kinetic freeze-out. In low-multiplicity collisions, unlike in high-multiplicity collisions, two-pion correlations are substantially altered by background correlations, e.g. mini-jets. Such correlations can be suppressed using three-pion cumulant correlations. We present the first measurements of the size of the system at freeze-out extracted from three-pion cumulant correlations in pp, p–Pb and Pb–Pb collisions at the LHC with ALICE. At similar multiplicity, the invariant radii extracted in p–Pb collisions are found to be 5–15% larger than those in pp, while those in Pb–Pb are 35–55% larger than those in p–Pb. Our measurements disfavor models which incorporate substantially stronger collective expansion in p–Pb as compared to pp collisions at similar multiplicity.
    Physics Letters B 10/2014; 739. DOI:10.1016/j.physletb.2014.10.034 · 6.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We discuss the results of femtoscopic correlations performed by various experiments at the Large Hadron Collider and theoretical efforts to interpret them. Two-particle low relative momentum correlations are used to measure the size of the region emitting particles in nuclear collisions. In pp collisions it is important to test the spatio-temporal characteristics of particle production at small scales. The results are compared to sizes measured in Pb+Pb collisions, as a function of pair momentum and centrality. They are interpreted in the frame of hydrodynamic models and used to test the hypothesis of the collective behavior of matter in such collisions.
    The European Physical Journal Conferences 01/2014; 71:00069. DOI:10.1051/epjconf/20147100069
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report on the results of femtoscopic analyses of Pb-Pb collisions at root s(NN)=2.76 TeV and pp collisions at root s= 7 TeV with identical charged and neutral kaons. The femtoscopic correlations allow one to measure the space-time characteristics of particle production using particle correlations due to the effects of quantum statistics for identical particles and final state interaction for both identical and non-identical ones. Small contributions from resonance decays make kaon femtoscopy an ideal tool for the correlation studies. In conjunction with pion and proton femtoscopy, they can also reveal properties of collective dynamics in heavy-ion collisions. ALICE results are compared with the existing world data on kaon femtoscopy in different type of collisions. The theoretical expectations for pp and Pb-Pb collisions are considered
    The European Physical Journal Conferences 01/2014; 71:00081. DOI:10.1051/epjconf/20147100081