Upsilon production and polarization in p p macro collisions at square root of s = 1.8 TeV.
Phys Rev Lett 88:16 (2002) 161802
Abstract:
We report on measurements of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections (d(2)sigma/dp(T)dy)(/y/<0.4), as well as on the Upsilon(1S) polarization in p p macro collisions at square root of s = 1.8 TeV using a sample of 77+/-3 pb(-1) collected by the collider detector at Fermilab. The three resonances were reconstructed through the decay Upsilon-->mu(+)mu(-). The measured angular distribution of the muons in the Upsilon(1S) rest frame is consistent with unpolarized meson production.Γ production and polarization in pp̄ collisions at √s = 1.8 TeV
Physical Review Letters 88:16 (2002) 1618021-1618026
Abstract:
The differential cross sections for the γ(1S), γ(2S), and γ(3S) states and the γ(1S) polarization were measured. Fits of nonrelativistic quantumchromodynamics (NRQCD) matrix elements could describe the cross sections. The polarization systematic uncertainties were also indicated. The polarization measurement was made by fitting the shape of the uncorrected data.Diffractive dijet production at sqrt[s] = 630 and 1800 GeV at the Fermilab Tevatron.
Phys Rev Lett 88:15 (2002) 151802
Abstract:
We report a measurement of the diffractive structure function F(D)(jj) of the antiproton obtained from a study of dijet events produced in association with a leading antiproton in pp collisions at sqrt[s] = 630 GeV at the Fermilab Tevatron. The ratio of F(D)(jj) at sqrt[s] = 630 GeV to F(D)(jj) obtained from a similar measurement at sqrt[s] = 1800 GeV is compared with expectations from QCD factorization and other theoretical predictions. We also report a measurement of the xi ( x-Pomeron) and beta ( x of parton in Pomeron) dependence of F(D)(jj) at sqrt[s] = 1800 GeV. In the region 0.035High-mass dijet cross sections in photoproduction at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 531:1-2 (2002) 9-27
Abstract:
Dijet differential cross sections for the reaction e+ p → e+ + jet + jet + X in the photoproduction regime have been measured with the ZEUS detector at HERA using an integrated luminosity of 42.7 pb-. The cross sections are given for photon-proton centre-of-mass energies in the range 134 < W < 277 GeV. The differential cross sections as a function of the dijet mass, MJJ, and of the dijet angular variables have been measured for 47 < MJJ < 160 GeV and compared to next-to-leading-order QCD calculations. The dijet events in the region 75 < MJJ < 100 GeV have been used to derive a 95% C.L. upper limit on the cross section for Z0 photoproduction of σ e+p→e+Z0X < 5.9 pb. Upper limits on the photoproduction of new heavy resonances decaying into two jets are also presented for masses in the range between 60 GeV and 155 GeV. © 2002 Elsevier Science B.V. All rights reserved.Dijet photoproduction at HERA and the structure of the photon
European Physical Journal C 23:4 (2002) 615-631