Papers by Angela Valentin Mari
The inclusive transverse momentum (p T ) distributions of primary charged particles are measured ... more The inclusive transverse momentum (p T ) distributions of primary charged particles are measured in the pseudo-rapidity range |η| < 0.8 as a function of event centrality in Pb-Pb collisions at √ s NN = 2.76 TeV with ALICE at the LHC. The data are presented in the p T range 0.15 < p T < 50 GeV/c for nine centrality intervals from 70-80% to 0-5%. The results in Pb-Pb are presented in terms of the nuclear modification factor R AA using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-p T particles strongly depends on event centrality. The yield is most suppressed in central collisions (0-5%) with R AA ≈ 0.13 at p T = 6-7 GeV/c. Above p T = 7 GeV/c, there is a significant rise in the nuclear modification factor, which reaches R AA ≈ 0.4 for p T > 30 GeV/c. In peripheral collisions (70-80%), only moderate suppression (R AA = 0.6-0.7) and a weak p T dependence is observed. The measured nuclear modification factors are compared to other measurements and model calculations.
Physical Review D, 2011
We report on the high statistics two-pion correlation functions from pp collisions at √ s = 0.9 T... more We report on the high statistics two-pion correlation functions from pp collisions at √ s = 0.9 TeV and √ 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 threedimensional 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 non-femtoscopic 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 π + π − correlations. 25.75.Gz, 25.70.Pq
The production cross section of electrons from semileptonic decays of beauty hadrons was measured... more The production cross section of electrons from semileptonic decays of beauty hadrons was measured at mid-rapidity (|y| < 0.8) in the transverse momentum range 1 < p T < 8 GeV/c with the ALICE experiment at the CERN LHC in pp collisions at a center of mass energy √ s = 7 TeV using an integrated luminosity of 2.2 nb −1 . Electrons from beauty hadron decays were selected based on the displacement of the decay vertex from the collision vertex. A perturbative QCD calculation agrees with the measurement within uncertainties. The data were extrapolated to the full phase space to determine the total cross section for the production of beauty quark-antiquark pairs. * See Appendix A for the list of collaboration members Electrons from beauty hadron decays in pp collisions at √ s = 7 TeV 1
Measurements of cross sections of inelastic and diffractive processes in proton-proton collisions... more Measurements of cross sections of inelastic and diffractive processes in proton-proton collisions at LHC energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single diffraction (diffractive mass M X < 200 GeV/c 2 ) σ SD /σ INEL = 0.21 ± 0.03, 0.20 +0.07 −0.08 , and 0.20 +0.04 −0.07 , respectively at centre-of-mass energies
El propósito de un ensayo de compactación en laboratorio es determinar la curva de compactación p... more El propósito de un ensayo de compactación en laboratorio es determinar la curva de compactación para una determinada energía de compactación. Esta curva considera en abscisas el contenido de humedad y en ordenadas la densidad seca. A partir de ella, se podrá obtener la humedad llamada óptima que es la que corresponde a la densidad máxima. Con estos resultados se podrá determinar la cantidad de agua de amasado a usar cuando se compacta el suelo en terreno para obtener la máxima densidad seca para una determinada energía de compactación. Para cumplir este propósito, un ensaye de laboratorio debe considerar un tipo de compactación similar a la desarrollada en terreno con los equipos de compactación a especificar.
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Papers by Angela Valentin Mari