Determination of the total c(c)over-bar production cross section in 340 GeV/c Sigma(-)-nucleus interactions

The production of charmed particles by Sigma- of 340 Gev/c momentum was studied in the hyperon beam experiment WA89 at the CERN-SPS, using the Omega-spectrometer. In two data-taking periods in 1993 and 1994 an integrated luminosity of 1600 microb^-1 on copper and carbon targets was recorded. From the reconstruction of 930 +- 90 charm particle decays in 10 decay channels production cross sections for D, antiD, Ds and Lambdac were determined in the region xF>0. Assuming an A^1 dependence of the cross section on the nucleon number, we calculate a total ccbar production cross section of sigma(x_F > 0) = 5.3+- 0.4(stat)+-1.0(syst)+1.0(Xi_c) microb per nucleon. The last term is an upper limit on the unknown contribution from charmed-strange baryon production.The production of charmed particles by Sigma- of 340 Gev/c momentum was studied in the hyperon beam experiment WA89 at the CERN-SPS, using the Omega-spectrometer. In two data-taking periods in 1993 and 1994 an integrated luminosity of 1600 microb^-1 on copper and carbon targets was recorded. From the reconstruction of 930 +- 90 charm particle decays in 10 decay channels production cross sections for D, antiD, Ds and Lambdac were determined in the region xF>0. Assuming an A^1 dependence of the cross section on the nucleon number, we calculate a total ccbar production cross section of sigma(x_F > 0) = 5.3+- 0.4(stat)+-1.0(syst)+1.0(Xi_c) microb per nucleon. The last term is an upper limit on the unknown contribution from charmed-strange baryon production.The production of charmed particles by Sigma- of 340 Gev/c momentum was studied in the hyperon beam experiment WA89 at the CERN-SPS, using the Omega-spectrometer. In two data-taking periods in 1993 and 1994 an integrated luminosity of 1600 microb^-1 on copper and carbon targets was recorded. From the reconstruction of 930 +- 90 charm particle decays in 10 decay channels production cross sections for D, antiD, Ds and Lambdac were determined in the region xF>0. Assuming an A^1 dependence of the cross section on the nucleon number, we calculate a total ccbar production cross section of sigma(x_F > 0) = 5.3+- 0.4(stat)+-1.0(syst)+1.0(Xi_c) microb per nucleon. The last term is an upper limit on the unknown contribution from charmed-strange baryon production

First observation of the Xi(-) pi(+) decay mode of the Xi(0)(1690) hyperon

We report the first observation of the Xi- pi+ decay mode of the Xi0(1690), confirming the existence of this resonance. The Xi0(1690) were produced by Sigma- of 345 Gev/c mean momentum in copper and carbon targets. The mass and width are close to those observed earlier for the Xi-(1690) in the Lambda K- decay channel. The product of inclusive production cross section and branching ratio is given relative to that of the Xi0(1530).We report the first observation of the Xi- pi+ decay mode of the Xi0(1690), confirming the existence of this resonance. The Xi0(1690) were produced by Sigma- of 345 Gev/c mean momentum in copper and carbon targets. The mass and width are close to those observed earlier for the Xi-(1690) in the Lambda K- decay channel. The product of inclusive production cross section and branching ratio is given relative to that of the Xi0(1530)

Production of Xi* resonances in Sigma(-) induced reactions at 345 GeV/c

We report on a measurement of the differential and total cross sections of inclusive production of Xi resonances in Sigma - nucleus collisions at 345 GeV/c.Comment: to be published in Eur. Phys. J.

A Measurement of Lambda Polarization in Inclusive Production by Sigma- of 340- GeV/c in C and Cu Targets

We have measured the polarization of Sigma(-) beam of 340 GeV/c momentum in nuclear targets. From a sample of 9.5 millions of identified Lambda decays, polarizations were determined in the range x(F) gt 0.1 and p(t)less than or equal to1.6 GeV/c . The polarization w.r.t. the production normal is mainly positive for x(F)greater than or equal to0.3. At fixed values of x(F) , it increases with p(t) to a maximum between p(t)=0.5 and p(t)=1 GeV/c , and then decreases to zero or even negative values, in sharp contrast to the plateau above p(t)=1 GeV/c observed in inclusive Lambda production by protons

A study of Sigma(+/-), Sigma(*+/-) and (Sigma)over-bar(1385)(-) production in the hyperon beam experiment WA89 at CERN

We report on a measurement of the inclusive production cross sections for Z(+/-), Z(1385)(+/-), Z(1660)(+/-) and (Σ) over bar ((1) over bar 385) in the CERN hyperon beam experiment WA89, using a Sigma(-)/pi(-) beam of 345 GeV/c momentum and neutrons of 260 GeV/c mean momentum. A strong leading particle effect was observed for all negative Sigma and Sigma*. The results are compared with predictions from phenomenological models