37 research outputs found
A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE
In this small note we are concerned with the solution of Forward-Backward
Stochastic Differential Equations (FBSDE) with drivers that grow quadratically
in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem
is a comparison result that allows comparing componentwise the signs of the
control processes of two different qgFBSDE. As a byproduct one obtains
conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
Charged-particle multiplicities in proton-proton collisions at root s=0.9 to 8 TeV
A detailed study of pseudorapidity densities and multiplicity distributions of primary charged particles produced in proton-proton collisions, atv root s = 0.9, 2.36, 2.76, 7 and 8 TeV, in the pseudorapidity range vertical bar n vertical bar<2, was carried out using the ALICE detector. Measurements were obtained for three event classes: inelastic, non-single diffractive and events with at least one charged particle in the pseudorapidity interval vertical bar n vertical barPeer reviewe
Pion, kaon, and proton production in central Pb-Pb Collisions at TeV
In this Letter we report the first results on , K, p and
production at mid-rapidity () in
central Pb-Pb collisions at = 2.76 TeV, measured by the
ALICE experiment at the LHC. The distributions and yields are
compared to previous results at = 200 GeV and expectations
from hydrodynamic and thermal models. The spectral shapes indicate a strong
increase of the radial flow velocity with , which in
hydrodynamic models is expected as a consequence of the increasing particle
density. While the ratio is in line with predictions from the
thermal model, the ratio is found to be lower by a factor of
about 1.5. This deviation from thermal model expectations is still to be
understood.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/286
Elliptic flow of electrons from heavy-flavour hadron decays at mid-rapidity in Pb-Pb collisions at root s(NN)=2.76 TeV
The elliptic flow of electrons from heavy-flavour hadron decays at mid-rapidity (|y| <0.7) is measured in Pb-Pb collisions at TeV with ALICE at the LHC. The particle azimuthal distribution with respect to the reaction plane can be parametrized with a Fourier expansion, where the second coefficient (v (2)) represents the elliptic flow. The v (2) coefficient of inclusive electrons is measured in three centrality classes (0-10%, 10-20% and 20-40%) with the event plane and the scalar product methods in the transverse momentum (p (T)) intervals 0.5-13 GeV/c and 0.5-8 GeV/c, respectively. After subtracting the background, mainly from photon conversions and Dalitz decays of neutral mesons, a positive v (2) of electrons from heavy-flavour hadron decays is observed in all centrality classes, with a maximum significance of 5.9 sigma in the interval 2 <p (T) <2.5 GeV/c in semi-central collisions (20-40%). The value of v (2) decreases towards more central collisions at low and intermediate p (T) (0.5 <p (T) <3 GeV/c). The v (2) of electrons from heavy-flavour hadron decays at mid-rapidity is found to be similar to the one of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4). The results are described within uncertainties by model calculations including substantial elastic interactions of heavy quarks with an expanding strongly-interacting medium.Peer reviewe
W and Z boson production in p-Pb collisions at s N N = 5.02 TeV
The W and Z boson production was measured via the muonic decay channel in proton-lead collisions at sNN=5.02 TeV at the Large Hadron Collider with the ALICE detector. The measurement covers backward (−4.46 10 GeV/c are determined. The results are compared to theoretical calculations both with and without including the nuclear modification of the parton distribution functions. The W-boson production is also studied as a function of the collision centrality: the cross section of muons from W-boson decays is found to scale with the average number of binary nucleon-nucleon collisions within uncertainties.[Figure not available: see fulltext.
Measurement of charm production at central rapidity in proton-proton collisions at 1as = 2.76 TeV
The pt-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D0, D+, and D+ in the rapidity range |y| K 12\u3c0+, D+ -> K 12\u3c0+\u3c0+, D+ -> D0\u3c0+, and their charge
conjugates, and was performed on a Lint = 1.1 nb 121 event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at ps = 2.76 TeV and at
7 TeV was evaluated by extrapolating to the full phase space the pt-differential production cross sections at ps = 2.76 TeV and our previous measurements at ps = 7 TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cd(bar) D mesons produced in a vector state was also determined
Centrality dependence of (sic)(2S) suppression in p-Pb collisions at root s(NN)=5.02 TeV
Peer reviewe