University of Perugia

About: University of Perugia is a education organization based out in Perugia, Umbria, Italy. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 13365 authors who have published 39516 publications receiving 1265601 citations. The organization is also known as: Universitá degli Studi di Perugia & Universita degli Studi di Perugia.

Chemical reaction dynamics with molecular beams

Abstract: This review describes advances which have occurred during the past decade in chemical reaction dynamics using crossed molecular beams. After a brief historical introduction, advances in the generation and state selection of beams of reactants, and in the schemes for product detection, which are at the basis of our increased ability to measure state-averaged and state-resolved reactive differential cross sections in crossed beam experiments, are described. The novel couplings of laser and synchrotron radiation to these experiments are noted. A selection of case studies are considered in some detail, to exemplify recent improvements in our understanding of gas-phase neutral reaction dynamics. The examples include prototype reactions involving three-atom and four-atom systems, and the results are discussed in the light of the most recent, synergistic, theoretical developments for treating both the potential energy surfaces and the reaction dynamics. Progress made in studies of reactions of molecular radicals and of chemically important atoms, such as carbon, nitrogen, and oxygen, with polyatomic molecules, as made possible by recent developments in the classic crossed beam technique with mass spectrometric detection, is emphasized. Some complementary techniques that recently have contributed to our understanding of chemical reactivity are also described briefly.

Detection of gamma-ray emission from the starburst galaxies m82 and ngc 253 with the large area telescope on fermi

Abstract: We report the detection of high-energy gamma-ray emission from two starburst galaxies using data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Steady point-like emission above 200 MeV has been detected at significance levels of 6.8 sigma and 4.8 sigma respectively, from sources positionally coincident with locations of the starburst galaxies M82 and NGC 253. The total fluxes of the sources are consistent with gamma-ray emission originating from the interaction of cosmic rays with local interstellar gas and radiation fields and constitute evidence for a link between massive star formation and gamma-ray emission in star-forming galaxies.

Suppression of non-prompt J/ψ, prompt J/ψ, and Y(1S) in PbPb collisions at √s NN = 2.76 TeV

Abstract: Yields of prompt and non-prompt J/psi, as well as Y(1S) mesons, are measured by the CMS experiment via their dimuon decays in PbPb and pp collisions at sqrt(sNN) = 2.76 TeV for quarkonium rapidity |y|<2.4. Differential cross sections and nuclear modification factors are reported as functions of y and transverse momentum pt, as well as collision centrality. For prompt J/psi with relatively high pt (6.5