315 research outputs found
Generación de locomoción para un robot hexápodo usando aprendizaje por refuerzo profundo
No full textEn este trabajo, introducimos una metodología basada en aprendizaje por refuerzo para el aprendizaje de la locomoción de un robot hexápodo sobre distintos tipos de terrenos. Durante el entrenamiento, a medida que el robot va experimentando con terrenos cada vez más desafiantes, incrementaremos progresivamente su dificultad. La hipótesis central de este trabajo es que, posteriormente a la etapa de aprendizaje, el robot pueda adaptarse a terrenos no explorados durante su entrenamiento. Los experimentos realizados en simulación utilizando Gazabo muestra la factibilidad del enfoque propuesto. El sistema fue desarrollado bajo ROS (Robot Operating System) y se encuentra disponible para la comunidad en https://github.com/lrse/hexapod-locomotion/.Fil: Sandacz, Matías. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
The GPD program at COMPASS
No full textThe 160 GeV polarised muon beam available at CERN, with positive or negative charge, makes COMPASS a unique place for GPD studies. The first GPD related COMPASS results come from exclusive vector meson production on transversely polarised protons and deuterons. The data were taken in 2003-2010 with large solid-state polarised targets, although without detection of recoil particles. Results on various transverse target spin dependent azimuthal asymmetries are presented and their relations to GPDs are discussed. The dedicated COMPASS GPD program started in 2012 with commissioning of a new long liquid hydrogen target and new detectors such as the large recoil proton detector and the large-angle electromagnetic calorimeter. It was followed by a short pilot 'DVCS run'. The performance of the setup and first results on DVCS and exclusive channels have been demonstrated. The full data taking for the GPD program approved within COMPASS-II proposal is planned for 2016 and 2017.The 160 GeV polarised muon beam available at CERN, with positive or negative charge, makes COMPASS a unique place for GPD studies. The first GPD related COMPASS results come from exclusive vector meson production on transversely polarised protons and deuterons. The data were taken in 2003-2010 with large solid-state polarised targets, although without detection of recoil particles. Results on various transverse target spin dependent azimuthal asymmetries are presented and their relations to GPDs are discussed. The dedicated COMPASS GPD program started in 2012 with commissioning of a new long liquid hydrogen target and new detectors such as the large recoil proton detector and the large-angle electromagnetic calorimeter. It was followed by a short pilot 'DVCS run'. The performance of the setup and first results on DVCS and exclusive channels have been demonstrated. The full data taking for the GPD program approved within COMPASS-II proposal is planned for 2016 and 2017
Program of COMPASS-II at CERN
No full textCOMPASS collaboration has started in 2012 a five-year program of new measurements, which are outlined in the 'COMPASS-II' proposal. The two new major projects of the proposal are measurements of polarized Drell-Yan process in π- scattering off transversely polarized protons and studies of GPDs via measurements of Deeply Virtual Compton Scattering and Hard Exclusive Meson Production in muon scattering off a liquid hydrogen target. In addition, high statistics SIDSI measurements with muon beams and a study of charged pion and kaon polarizabilities via Primakoff reactions with hadron beams are also foreseen as a part of this program
Diffractive production at COMPASS experiment
No full textThe helicity structure of the diffractive leptoproduction of mesons, , is studied and preliminary results on several spin density matrix elements and for incoherent exclusive production from COMPASS 2002 data are presented. The elements , , , and are measured at 10 GeV in a wide range of , 0.01 10 GeV. The data are consistent with a substantial increase of with and a weak violation of SCHC, in agreement with other high energy experiments
The GPD program at COMPASS
No full textThe high energy polarised muon beam available at CERN, with positive or negative charge, make COMPASS a unique place for GPD studies. The COMPASS program of GPD studies is reviewed and various observables for this program and expected accuracies are discussed. The necessary developements of the experimental setup and the first results of the test runs are also presented
Hard exclusive meson production in muon scattering at COMPASS
No full textWe report on measurements of hard exclusive muoproduction of ρ0, ω and π0 mesons on the proton at COMPASS using 160 GeV/c polarized μ+ and μ− beams scattering off a liquid hydrogen target. The extracted Spin Density Matrix Elements for vector mesons indicate a violation of s-channel helicity conservation for transitions of transversely polarized virtual photons to longitudinally polarized vector mesons, γT → VL, where V denotes ρ0 or ω meson. Additionally, for ρ0 production we observe a dominant contribution of natural-parity-exchange transitions and a small contribution of unnaturalparity-exchange transitions. On the contrary, the contribution of unnaturalparity-exchange for ω production is significant and it decreases with increasing W, being still non-negligible at the largest W values accessible at COMPASS. Further, we present also the absolute value of the differential cross section for exclusive π0 production and its dependence on squared four-momentum transfer t and azimuthal angle ø between the scattering plane and π0 production plane. The results provide an important input for modeling Generalized Parton Distribution (GPDs), and in particular to constrain chiral-odd (transversity) GPDs
The GPD program at COMPASS
No full textThe COMPASS proposed program of the Generalised Parton Distribution (GPD) studies is reviewed. Various observables for this program and the expected accuracies are discussed. The necessary developements of the experimental setup and the first results from the test run are also presented
- …
