An exclusive measurement of the decay η→π+π−γ has been performed at the WASA facility at COSY. The η mesons were produced in the fusion reaction pd→He3 X at a proton beam momentum of 1.7 GeV/c. ...Efficiency corrected differential distributions have been extracted based on 13960±140 events after background subtraction. The measured pion angular distribution is consistent with a relative p-wave of the two-pion system, whereas the measured photon energy spectrum was found at variance with the simplest gauge invariant matrix element of η→π+π−γ. A parameterization of the data can be achieved by the additional inclusion of the empirical pion vector form factor multiplied by a first-order polynomial in the squared invariant mass of the π+π− system.
The results on atmospheric deposition of heavy metals and other trace elements using the moss biomonitoring technique in the northern part of Serbia and some areas of Bosnia-Herzegovina are ...presented. Samples of Hypnum cupressiforme along with some other moss types were collected at 92 sites during the summer of 2000. A total of 44 elements were determined by INAA using epithermal neutrons. High values of Cl and V content in the moss samples at certain areas are suspected to be associated with fires in oil refineries damaged during the 1999 NATO military action.
Two modular Cherenkov detectors FFD and T0 are developed for MPD and BM@N projects at LHEP/JINR for study of Au + Au collisions. The aim of the detectors is production of a start signal for a TOF ...detector and an effective L0 trigger for the collisions. The detector module design, characteristics, and results of tests with a deuteron beam are discussed. The time resolution of the modules for a single high energy photon or charged hadron is σ
t
≈ 21–31 ps and it depends on method and electronics used.
Concept of a fast forward detector (FFD) developed as part of Multi-Purpose Detector (MPD) setup for future experiments with beams of nuclear collider NICA is described. The FFD is aimed at ...triggering nucleus-nucleus collisions at the center of the MPD setup and generating start pulse for TOF detector. Two units of the detector module were designed, produced, and tested with cosmic rays and proton beam. The time resolution obtained in the measurements is ∼30 ps (sigma). Results of simulation, prototype developing and experimental tests are discussed.
An exclusive measurement of the decay eta arrow right pi super(+) pi super(-) gamma has been performed at the WASA facility at COSY. The eta mesons were produced in the fusion reaction inline image X ...at a proton beam momentum of 1.7 GeV/c. Efficiency corrected differential distributions have been extracted based on inline image events after background subtraction. The measured pion angular distribution is consistent with a relative p-wave of the two-pion system, whereas the measured photon energy spectrum was found at variance with the simplest gauge invariant matrix element of eta arrow right pi super(+) pi super(-) gamma . A parameterization of the data can be achieved by the additional inclusion of the empirical pion vector form factor multiplied by a first-order polynomial in the squared invariant mass of the pi super(+) pi super(-) system.
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