35 research outputs found
Evidence for new resonances in the systems
No full textPartial-wave analysis has been performed on 120 000 - -+ events coherently produced on nuclear targets in a - beam of 40 GeV/c. Evidence has been found for a 0- S resonance at 1.24 GeV with a width 0.36 GeV. The data also suggest the presence of another 0- S resonance of similar width near 1.8 GeV. These observations can be interpreted as radial excitations of the meson
Carolina Ortega, soprano (Colombia)
No full textConcierto interpretado por la soprano Carolina Ortega, en compañía del pianista Sergei Sychkov. Ortega nació en Bogotá en 1977. Inició sus estudios en la Pontificia Universidad Javeriana en 1995; empezó los de canto en 1997 con el maestro Wilmer García y posteriormente los continuó con la maestra María Olga Piñeros. Durante su carrera participó en los conciertos de estudiantes y en los martes musicales realizados en el auditorio Luis Carlos Galán de la universidad, y en varias oportunidades se desempeñó como solista del coro de la carrera en obras como el Magnificat de J. S. Bach y el Réquiem de W. A. Mozart
Coherent production of 3pi states at 25 GeV/c
No full textThe coherent production of π-π-π+ states has been studied at 25.7 GeV incident energy with an Al target. The partial-wave analysis of the data confirms the evidence of a I GJPL=1-0- S resonant state in the mass region near to 1.2 GeV, already found by our collaboration at 40 GeV incident energy
Semicoherent elastic pion-carbon scattering at 25 and 40 GeV/c
No full textIn the frame of a systematic study of hadron-nucleus interactions performed at the Serpukhov accelerator (CERN-IHEP 5th experiment), semicoherent elastic scattering on carbon pi /sup -12/C to pi /sup -12 /C* (4.44 MeV) was investigated with 25 and 40 GeV/c incident pions. The experimental data were obtained with a counter technique, looking at the coincidence between the scattered pion and the 4.44 MeV photon from the J/sup P/=2/sup +/ carbon excited state detected by a NaI counter. The value obtained for the integrated cross section at 40 GeV /c in the 0.0032<or= mod t mod <or=0.27 (GeV/c)/sup 2/ four-momentum transfer range is sigma =1.16+or-0.11 mb. According to the theoretical models, this t-range at 40 GeV/c covers more than 90% of the angular distribution, so the above value almost corresponds to the total semicoherent elastic cross section. (13 refs)
Study of coherent inelastic diffraction of a 40-GeV/c. pi. /sup -/ meson in a silicon target-detector
No full textThe (3π)-nucleon collision in coherent production on nuclei at 40 GeV/c
No full textCoherent 3π production on nine different nuclear targets has been studied using a 40 GeV/c π- beam at the Serpukhov accelerator (CERN-Serpukhov experiment no. 5). The absorption in nuclear matter of the produced system has been measured, analysing the data on the different nuclear targets. Identica results are obtained from the differential cross sections and from the coherent nuclear cross sections. The 1+ waves show a very weak absorption, definitely smaller than 0- and 2- waves. No influence on the absorption comes from the spin-flip amplitudes, which have been found to be negligible in the coherent region
Multiplicity of charged particles in interactions on nuclei at 40 GeV/c
No full textMultiparticle production in π--nucleus interactions at 40 GeV/c (Fifth Joint CERN-Serpukhov Experiment) has been studied using a spark-chamber technique at the Serpukhov accelerator. The mean multiplicities, the pseudorapidity distributions and the dispersion of the multiplicity distributions of charged particles produced on C, Al, Cu and Pb targets are presented. The data have been analysed, both subtracting and including secondary protons with p 3.4 the average multiplicity is nearly independent of the size (ν) of the target nucleus, while it increases for η 4) the mean multiplicity on nuclei is smaller than the mean multiplicity on hydrogen. The dependence upon ν in the target fragmentation region is stronger when the emitted protons are included in the pseudorapidity distributions of the secondary particles. The dispersion of the multiplicity distributions for the different nuclear targets versus the mean multiplicity shows the same slope as found by the world statistics on hydrogen and by other experiments on nuclei at different energies. The results are compared with the predictions of the coherent tube model and with the soft hadron-nucleus collision model
Morphology of the γ → α recrystalllization front with diffusional change in composition of complex iron alloys
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