We present a total of 427 np analyzing power data points in a large angular interval at 12 energies between 0.312 and 1.10 GeV. The SATURNE II polarized beam of free monochromatic neutrons was scattered either on the Saclay frozen-spin polarized proton target or on CH 2 and C targets. Present results are compared with existing elastic and quasieleastic data.
Results of the analyzing power for n p scattering at 0.312 GeV. The CH2 target was used.
Results of the analyzing power for n p scattering at 0.363 GeV. The CH2 target was used.
Results of the analyzing power for n p scattering at 0.800 GeV.
We present first results on the total photoproduction cross section measurement with the H1 detector at HERA. The data were extracted from low Q 2 collisions of 26.7 GeV electrons with 820 GeV protons. The γp total cross section has been measured by two independent methods in the γp center of mass energy range from 90 to 290 GeV. For an average center of mass energy of 195 GeV a value of σ tot ( γp ) = 159 ± 7 (stat.) ± 20 (syst.) μb was obtained.
Data from tagged sample.
Data from untagged sample.
Multiplicity distributions of negatively charged particles have been studied in restricted phase space intervals for central S+S, O+Au and S+Au collisions at 200 GeV/nucleon. It is shown that multiplicity distributions are well described by a negative binomial form irrespectively of the size and dimensionality of phase space domain. A clan structure analysis reveals interesting similarities between complex nuclear collisions and a simple partonic shower. The lognormal distribution agrees reasonably well with the multiplicity data in large domains, but fails in the case of small intervals. No universal scaling function was found to describe the shape of multiplicity distributions in phase space intervals of varying size.
Multiplicity distribution analysed in 1D for M = 4.
Multiplicity distribution analysed in 2D for M = 16.
Multiplicity distribution analysed in 3D for M = 64.
Production of charged kaons in proton-sulphur, proton-gold, sulphur-sulphur and oxygen-gold collisions at 200 GeV/nucleon has been studied in the NA35 Streamer Chamber experiment. Rapidity and transverse mass distributions as well as mean multiplicities were obtained. The results are compared with nucleon-nucleon data and with model predictions.
Tranverse mass distribution for all charged kaons in S S collisions for the limited yrap range 1.4 to 2.4.
Tranverse mass distribution for K0S production in the limited rapidity range 1.4 to 2.4. Data are taken from Bartke et al. ZP C48 (1990) 191.
Rapidity distribution for K+ production in p SU interactions.
A study of inclusive production of the meson resonances ρ 0 , K ∗0 (892), ƒ 0 (975) and ƒ 2 (1270) in hadronic decays of the Z 0 is presented. The measured mean meson multiplicity per hadronic event is 0.83 ± 0.14 for the ρ 0 0.64 ± 0.24 for the K ∗0 (892), 0.10 ± 0.04 for the ƒ 0 (975) in the momentum range p > 0.05 p beam ( x p > 0.05) and 0.11 ± 0.05 for the ƒ 2 (1270) for x p > 0.1 . These values and the corresponding differential cross sections ( 1 σ hadr ) d σ d x p for the vector mesons are in good agreement with the predictions of the JETSET 7.3 PS and HERWIG 5.4 models. The ƒ 2 (1270) production is overestimated by HERWIG but its x p -shape is correctly reproduced. The measured ratios of the production cross sections σ(ƒ 2 (1270)) σ(ρ 0 ) = 0.22 ± 0.08 and σ(ƒ 2 (1270)) σ(ƒ 0 (975)) = 3 −1 +7 for x p > 0.1 are consistent with the results obtained in hadronic reactions.
Average multiplicity per hadronic event. Extrapolation to x = 0 using the x shape predicted by JETSET 7.3 PS.
Average multiplicity per hadronic event. Extrapolation to x = 0 using the x shape predicted by JETSET 7.3 PS.
Average multiplicity per hadronic event. Extrapolation to x = 0 using the x shape predicted by JETSET 7.3 PS.
We present results from an experimental study of reabsorption effects in subthreshold π0 production in the reaction Xe129+197Au at 44 MeV/nucleon. Within the picture of pion generation in nucleon-nucleon scattering we deduce, from our data and from a comparison with the systematics of production cross sections available for lighter reaction systems, information on the π0 absorption length in nuclear matter. For the π0 kinetic-energy range ≃5–100 MeV the energy-averaged λabs and its momentum dependence are obtained, and compared with optical-model calculations.
No description provided.
No description provided.
No description provided.
We measure the relative cross sections for D mesons produced in interactions of π− and π+ beams with targets of Be, Cu, Al, and W. The measurement is based on 1400 fully reconstructed decays of the types D0→K−π+, D+→K−π+π+, and charge conjugates. We find that the cross section for the production of both neutral and charged D’s by either π− or π+ is well fitted by the form Aα where A is the atomic mass and α=1.00±0.05±0.02, where the errors are statistical and systematic, respectively. There is no significant dependence of α on the transverse or longitudinal momentum of the D meson or on the charge of either the incident pion or the produced D mesons.
No description provided.
The nuclear response of a medium-mass nucleus (136Xe) to electromagnetic excitation in a near-relativistic heavy-ion collision was investigated in the reaction136Xe(0.7A GeV)+Pb. From an exclusive measurement of the neutron decay of the excited Xe136 projectiles, strong excitations of giant resonances and, in particular, of the double isovector giant dipole resonance were identified. A resonance energy of 28.3±0.7 MeV, a width of 6.3±1.6 MeV, and a total cross section of 215±50 mb were found for the double giant dipole resonance.
CROSS SECTION FOR THE DOUBLE GIANT DIPOLE RESONANCE IN XE136.
Inclusive jet cross sections have been measured in p¯p collisions at √s =546 and 1800 GeV, using the Collider Detector at Fermilab. The ratio of jet cross sections is compared to predictions from simple scaling and O(as3) QCD. Our data exclude scaling and lie (1.5–2.4)σ below a range of QCD predictions.
Additional systematic uncertainty +23,-26 pct.
Additional systematic uncertainty +-16 pct.
Additional systematic uncertainty +-0.22.
Measurements of the forward-angle differential cross section for elastic electron-proton scattering were made in the range of momentum transfer from Q2=2.9 to 31.3 (GeV/c)2 using an electron beam at the Stanford Linear Accelerator Center. The data span six orders of magnitude in cross section. Combinded statistical and systematic uncertainties in the cross section measurements ranged from 3.6% at low Q2 to 19% at high Q2. These data have been used to extract the proton magnetic form factor GMp(Q2) and Dirac form factor F1p(Q2) by using form factor scaling. The logarithmic falloff of Q4F1p expected from leading twist predictions of perturbative quantum chromodynamics is consistent with the new data at high Q2. Some nonperturbative and hybrid calculations also agree with our results.
No description provided.
Formfactor scaling assumes (Ge=Gm/mu).
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