Research Collection Doctoral Thesis Comparison of the experimental cross-sections of high-mass muon pairs produced by negative pions on deuterium and tungsten Author(s): Guanziroli, Mario Publication Date: 1986 Permanent Link: https://doi.org/10.3929/ethz-a-000412385 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library ETH Diss. Nr. 7989 COMPARISON OF THE EXPERIMENTAL CROSS-SECTIONS OF HIGH-MASS MUON PAIRS PRODUCED BY NEGATIVE PIONS ON DEUTERIUM AND TUNGSTEN A dissertation submitted to the SWISS FEDERAL INSTITUTE OF TECHNOLOGY ZURICH for the degree of Doctor of Natural Sciences Presented by Mario GUANZIROLI graduate in physics of the ETH-Zurich born October 30,1952 citizen of Italy Accepted on the recommandation of Prof. V.L. Telegdi, Examiner Prof. H.Hofer, Co-Examiner 1986 ABSTRACT The cross-sections for massive lepton pair production by 284 GeV/c negative pions simultaneously on D2 and W, as measured with the NA10 spectrometer at the CERN SPS, are compared. Nuclear effects in the results are searched forjit is shown that, in the ratio tungsten/deuterium cross-section.there is evidence for a Xp-dependence: in the interval 0.30 < y/r < 0.36, this ratio has a slope of 1.30±0.47(stat.). The A-dependence of the total cross-section a(Z,A) = a0(Z/A)*Aa was determined with the best accuracy to date.yielding «' = 1.000+0.006(stat.)± 0.002(syst.). RIASSUNTO Si confrontano le sezioni efficaci di produzione di coppie di leptoni di massa elevata da parte di pioni negativi di 284 GeV/c simultaneamente su D2 e W, misurate con lo spettrometro NAIO all'SPS al CERN. Si cercano effetti nucleari nei risultati;si mostra che,nel rapporto delle sezioni efficaci tungsten- o/deuterio c'e evidenza di una dipendenza rispetto ad Xp: nell'intervallo 0.30 < ,/t < 0.36, tale rapporto ha una pendenza pari a 1.30±0.47(stat.). La dipendenza lineare rispetto ad A della sezione efficacie to- tale a(Z,A) = a0(Z/A)'Aa e stata verificata con la massima precisione finora raggiunta, ottenendo a'=1.000+0.006(stat.)±0.002(sist.)..