Showing papers by "Malgorzata Anna Janik published in 2011"
11 Jul 2011
TL;DR: The first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions is reported, and a double peaked structure in the two-particle azimuthal correlations is observed, which can be naturally explained from the measured anisotropic flow Fourier coefficients.
Abstract: We report on the first measurement of the triangular nu(3), quadrangular nu(4), and pentagonal nu(5) charged particle flow in Pb-Pb collisions at root s(NN) = 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow nu(2) and nu(3) have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.
515 citations
K. Aamodt1, A. Abrahantes Quintana, Dagmar Adamová2, Andrew Marshall Adare3 +919 more•Institutions (76)
TL;DR: In this paper, the first results obtained detecting the J/psi through the dilepton decay into e(+)e(-) and mu(+)mu(-) pairs in the rapidity ranges vertical bar y vertical bar < 0.9 and 2.5 < y < 4, respectively, and with acceptance down to zero PT.
167 citations
K. Aamodt1, A. Abrahantes Quintana, Dagmar Adamová2, Andrew Marshall Adare3 +919 more•Institutions (78)
TL;DR: In this article, high statistics two-pion correlation functions from pp collisions at the ALICE experiment at the Large Hadron Collider were reported, showing an increase of the emission zone with increasing event multiplicity and decreasing homogeneity lengths with increasing transverse momentum.
Abstract: We report on the high statistics two-pion correlation functions from pp collisions at root s = 0.9 TeV and root s = 7 TeV, measured by the ALICE experiment at the Large Hadron Collider. The correlation functions as well as the extracted source radii scale with event multiplicity and pair momentum. When analyzed in the same multiplicity and pair transverse momentum range, the correlation is similar at the two collision energies. A three-dimensional femtoscopic analysis shows an increase of the emission zone with increasing event multiplicity as well as decreasing homogeneity lengths with increasing transverse momentum. The latter trend gets more pronounced as multiplicity increases. This suggests the development of space-momentum correlations, at least for collisions producing a high multiplicity of particles. We consider these trends in the context of previous femtoscopic studies in high-energy hadron and heavy-ion collisions and discuss possible underlying physics mechanisms. Detailed analysis of the correlation reveals an exponential shape in the outward and longitudinal directions, while the sideward remains a Gaussian. This is interpreted as a result of a significant contribution of strongly decaying resonances to the emission region shape. Significant nonfemtoscopic correlations are observed, and are argued to be the consequence of "mini-jet"-like structures extending to low p(t). They are well reproduced by the Monte-Carlo generators and seen also in pi(+)pi(-) correlations.
135 citations
TL;DR: In this article, the pt-differential inclusive production cross sections of the prompt charmed mesons D0, D+, and D*+ in the rapidity range |y| K-pi+, D+->K-pi+pi+,D*+->D0pi+, and their charge conjugates were counted, after selection cuts, in a data sample of 3.14x10^8 events collected with a minimum-bias trigger.
Abstract: The pt-differential inclusive production cross sections of the prompt charmed mesons D0, D+, and D*+ in the rapidity range |y| K-pi+, D+->K-pi+pi+, D*+->D0pi+, and their charge conjugates, about 8,400 D0, 2,900 D+, and 2,600 D*+ mesons with 1
130 citations