Compensation of transverse momentum is studied in π+p interactions at 250 GeV/c. SignificantpT-transfer is found between c.m.s. hemispheres. With respect to the beam axis transverse momentum is compensated over the whole event, with respect to the sphericity axis mainly within one hemisphere. The highestpT in the event is mainly compensated by increased multiplicity. The QGSM and FRITIOF models qualitatively reproduce these effects, but important differences are observed.
Mean value of total transverse VECTOR defined as sum over all charged particles in the forward or backward hemispheres was measured.
Mean value of total transverse VECTOR defined as sum over all charged particles in the forward or backward hemispheres was measured.
No description provided.
A spectroscopic study of the CΛ12 hypernucleus by the (π+, K+) reaction has been performed using a new superconducting kaon spectrometer (INS-SKS) at the KEK 12 GeV Proton Synchrotron with an energy resolution of 2 MeV (FWHM). In addition to two prominent peaks which correspond to the s and p orbitals of a Λ hyperon, for the first time two smaller peaks were clearly observed at excitation energies of 2.6 and 6.9 MeV. These two peaks are interpreted as states where the C11 excited core and a Λ hyperon in the s orbit are weakly coupled. The excitation energies and the cross sections of these peaks provide information on the ΛN interaction.
No description provided.
A prompt photon cross section measurement from the Collider Detector at Fermilab experiment is presented. Detector and trigger upgrades, as well as 6 times the integrated luminosity compared with our previous publication, have contributed to a much more precise measurement and extended PT range. As before, QCD calculations agree qualitatively with the measured cross section, but the data has a steeper slope than the calculations.
Note that the sytematic uncertainties are approximately 100 pct correlated bin to bin.
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THE CROSS SECTION HAS BEEN FITTED BY THE FORMULA: D(SIG)/D(PT**2)= CONST*EXP(-SLOPE*PT**2).
We measured the spin asymmetry in the scattering of 100 GeV longitudinally-polarized muons on transversely polarized protons. The asymmetry was found to be compatible with zero in the kinematic range $0.006<x<0.6$, $1<Q~2<30\,\mbox{GeV}~2$. {}From this result we derive the upper limits for the virtual photon--proton asymmetry $A_2$, and for the spin structure function $g_2$. For $x<0.15$, $A_2$ is significantly smaller than its positivity limit $\sqrt{R}$.
No description provided.
Nucleon spin structure function g2.
Proton total reaction cross sections (σR) have been measured for the nuclei Ca42, Ca44, and Ca48 at seven energies each between 20.8 and 48.0 MeV. The experimental results plus our previously measured σR values for Ca40 are compared to the results of optical model analyses, both nonrelativistic and relativistic, of an extensive set of elastic scattering data for the same calcium isotopes in this energy range. The experimental results are also compared to global optical model predictions. In general, the theoretical values are in good agreement with the experimental results, with a slight preference for the relativistic analysis. In addition, our results are used in nuclear transparency calculations, which show that over the range of energies studied, the average nuclear transparency decreases by almost 15%.
No description provided.
No description provided.
This paper presents a measurement of J/psi,psi(2S) differential cross sections in p-pbar collisions at square root s = 1.8 TeV. The cross sections are measured above 4 GeV/c in the central region (|eta| < 0.6) using the dimuon decay channel. The fraction of events from B decays is measured, and used to calculate b quark cross sections and direct J/psi,psi(2S) cross sections. The direct cross sections are found to be more than an order of magnitude above theoretical expectations.
Cross sections are multiplied on branching ratio of J/PSI or PSI(2S), respectively.
The cross sections was evaluated form the J/PSI spectrum. The error is statistical and systematic errors, added in quadrature.
The cross sections was evaluated form the PSI(2S) spectrum. The error is statistical and systematic errors, added in quadrature.
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Charged B+ or B- meson cross section.
Charged B+ or B- meson cross section.
Neutral B0 or BBAR0 meson cross section.
None
No description provided.
No description provided.
No description provided.
The cross section for the process e + e − → p p has been measured in the s range 3.6–5.9 GeV 2 by the FENICE experiment at the e + e − Adone storage ring and the proton electromagnetic form factor has been extracted.
Cross section measurement.
Proton form-factor measurement.