Search results for "Collision"
showing 10 items of 908 documents
Decentralized Coordination System for Multiple AGVs in a Structured Environment
2011
Abstract In this paper, we propose a decentralized coordination algorithm for safe and efficient management of a group of mobile robots following predefined paths in a dynamic industrial environment. The proposed algorithm is based on shared resources and proved to guarantee ordered traffic flows avoiding collisions and deadlocks. In consistency with the model of distributed robotic systems (DRS), no centralized mechanism, synchronized clock, shared memory or ground support is needed. A local inter-robot communication is required among a small number of spatially adjacent robotic units.
Quantum Non-Markovian Collision Models from Colored-Noise Baths
2019
A quantum collision model (CM), also known as repeated interactions model, can be built from the standard microscopic framework where a system S is coupled to a white-noise bosonic bath under the rotating wave approximation, which typically results in Markovian dynamics. Here, we discuss how to generalize the CM construction to the case of frequency-dependent system–bath coupling, which defines a class of colored-noise baths. This leads to an intrinsically non-Markovian CM, where each ancilla (bath subunit) collides repeatedly with S at different steps. We discuss the illustrative example of an atom in front of a mirror in the regime of non-negligible retardation times.
ϕ meson production in the forward/backward rapidity region in Cu + Au collisions at √sNN = 200 GeV
2016
Measurement of D0, D+, D*+ and D+s production in pp collisions at √s = 5.02 TeV with ALICE
2019
The measurements of the production of prompt D0 , D+ , D∗+ , and D+s mesons in proton–proton (pp) collisions at s√=5.02 TeV with the ALICE detector at the Large Hadron Collider (LHC) are reported. D mesons were reconstructed at mid-rapidity ( |y|<0.5 ) via their hadronic decay channels D0→K−π+ , D+→K−π+π+ , D∗+→D0π+→K−π+π+ , D+s→ϕπ+→K+K−π+ , and their charge conjugates. The production cross sections were measured in the transverse momentum interval 0<pT<36 GeV/c for D0 , 1<pT<36 GeV/c for D+ and D∗+ , and in 2<pT<24 GeV/c for D+s mesons. Thanks to the higher integrated luminosity, an analysis in finer pT bins with respect to the previous measurements at s√=7 TeV was performed, allowing for …
D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions at √sNN = 5.02 TeV
2018
The azimuthal anisotropy coefficient v 2 of prompt D 0 , D + , D * + , and D + s mesons was measured in midcentral (30%–50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair √ s N N = 5.02 TeV , with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, | y | < 0.8 , in the transverse momentum interval 1 < p T < 24 GeV / c . The measured D -meson v 2 has similar values as that of charged pions. The D + s v 2 , measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically e…
Measurement of azimuthal correlations of D mesons with charged particles in pp collisions at √s = 7 TeV and p-Pb collisions at √sNN = 5.02 TeV
2017
The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at √s = 7 TeV and p–Pb collisions at √sNN = 5.02 TeV at the Large Hadron Collider. D0, D+, and D∗+ mesons and their charge conjugates with transverse momentum 3 0.3 GeV/c. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators. peerReviewed
Measurement of dijet production with a veto on additional central jet activity in pp collisions at sqrt(s)=7 TeV using the ATLAS detector
2011
A measurement of jet activity in the rapidity interval bounded by a dijet system is presented. Events are vetoed if a jet with transverse momentum greater than 20 GeV is found between the two boundary jets. The fraction of dijet events that survive the jet veto is presented for boundary jets that are separated by up to six units of rapidity and with mean transverse momentum 50 < p¯T < 500 GeV. The mean multiplicity of jets above the veto scale in the rapidity interval bounded by the dijet system is also presented as an alternative method for quantifying perturbative QCD emission. The data are compared to a next-to-leading order plus parton shower prediction from the powheg-box, an all-order…
Predictions for 5.023 TeV Pb + Pb collisions at the CERN Large Hadron Collider
2016
We compute predictions for various low-transverse-momentum bulk observables in √sNN = 5.023 TeV Pb+Pb collisions at the CERN Large Hadron Collider (LHC) from the event-by-event next-to-leading-order perturbative-QCD + saturation + viscous hydrodynamics (“EKRT”) model. In particular, we consider the centrality dependence of charged hadron multiplicity, flow coefficients of the azimuth-angle asymmetries, and correlations of event-plane angles. The centrality dependencies of the studied observables are predicted to be very similar to those at 2.76 TeV, and the magnitudes of the flow coefficients and event-plane angle correlations are predicted to be close to those at 2.76 TeV. The flow coeffic…
Limit on the production of a light vector gauge boson in $\phi $ mesondecays with the KLOE detector
2012
We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAPHNE. This boson, called U, has been searched for in the decay phi --> eta U, U --> e+ e-, analyzing the decay eta --> pi0 pi0 pi0 in a data sample of 1.7 fb-1. No structures are observed in the e+e- invariant mass distribution over the background. This search is combined with a previous result obtained from the decay eta --> pi+ pi- pi0, increasing the sensitivity. We set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of alpha'/alpha < 1.7x10^-5 for 30<M_U<400 MeV and alpha'/alpha < 8x10^-6 for the sub-region 50<M_U<210 MeV. This…