Results on K 0 and Λ production in p↑p interactions at 6 GeV are presented. The data are from an exposure of the Argonne 12 ft bubble chamber to a 60% transversely polarized proton beam. Results include data on Λ and K 0 inclusive production, and on the reactions p↑p → p Λ K + (p Σ 0 K + ). The beam asymmetry parameter for p ↑ p → K 0 ( K 0 ) + X is determined to be (−0.52 ± 0.12).
No description provided.
New data are presented, in the form of statistical tensors, for the reactions π + p → ( ϱ 0 , ω ) Δ ++ at 7.1 GeV/ c . Using these data, two types of model-dependent amplitude analyses have been performed. Both analyses, though based on different sets of assumptions, yield results which are in agreement with each other. The structure observed in the magnitudes and phases of the extracted amplitudes is consistent with that expected on the basis of currently accepted phenomenological ideas.
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Data are presented on the reactions π + n → ϱ 0 + X and K − p → K ∗0 + X at 6.0 and 7.3 GeV/ c , respectively. Comparisons are made between these two reactions and with other reactions involving inclusive vector meson production at different energies.
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The strong coupling constant, αs, has been determined in hadronic decays of theZ0 resonance, using measurements of seven observables relating to global event shapes, energy correlatio
Data corrected for finite acceptance and resolution of the detector and for intial state photon radiation. No corrections for hadronic effects are applied.. Errors include statistical and systematic uncertainties, added in quadrature.
Data corrected for finite acceptance and resolution of the detector and for intial state photon radiation. No corrections for hadronic effects are applied.. Errors include statistical and systematic uncertainties, added in quadrature.
Data corrected for finite acceptance and resolution of the detector and for intial state photon radiation. No corrections for hadronic effects are applied.. Errors include statistical and systematic uncertainties, added in quadrature.
An experimental investigation of the structure of identified quark and gluon jets is presented. Observables related to both the global and internal structure of jets are measured; this allows for test
The measured jet broadening distributions (B) in quark and gluon jets seperately.
Measured distributions of -LN(Y2), where Y2 is the differential one-subjet rate, that is the value of the subjet scale parameter where 2 jets appear from the single jet.
The mean subjet multiplicity (-1) for gluon jets and quark jets for different values of the subject resolution parameter Y0.
Analyzing powers ( A y ) and spin-rotation-depolarization parameters ( D SS , D SL , D LS , D LL , D NN ) were determined for 500 MeV p + 2 H and p + 12 C inclusive quasielastic scattering at 10°, 15°, and 20° laboratory scattering angles. The p + 2 H data are consistent with the isospin-average of the proton-proton and proton-neutron scattering observables; the p + 12 C data are not. A relativistic plane wave impulse approximation calculation leads to better agreement with the p + 12 C spin-observables.
Inclusive quasielastic p deut measurements.
Inclusive quasielastic p c measurements.
Differential cross sections of the reactions $(\gamma,\pi^\circ\pi^\circ)$ and $(\gamma,\pi^\circ\pi^++\pi^\circ\pi^-)$ have been measured for several nuclei ($^1$H,$^{12}$C, and $^{\rm nat}$Pb) at an incident-photon energy of $E_{\gamma}$=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass dependence of the $\pi\pi$ invariant-mass distribution is found in the $\pi^\circ\pi^\circ$ channel. This dependence is not observed in the $\pi^\circ\pi^{+/-}$ channel and is consistent with an in-medium modification of the $\pi\pi$ interaction in the $I$=$J$=0 channel. The data are compared to $\pi$-induced measurements and to calculations within a chiral-unitary approach.
Differential cross section for PI0PI0 production with a proton target. Errors are statistical only. Note that the data given in this table are sightly different (newer) than the data points presented in the paper.
Differential cross section for PI0PI0 production with a Carbon target. Errors are statistical only.
Differential cross section for PI0PI0 production with a Lead target. Errors are statistical only.
The electric form factor of the neutron GE,n has been measured in the quasifree 2H(e→,e′n→)p reaction using the 855 MeV polarized cw electron beam of the Mainz Microtron MAMI. The polarization of the scattered neutrons was analyzed in a polarimeter consisting of two walls of plastic scintillators. The precession of the neutron spin in a magnetic field was used for the first time to circumvent the measurement of the effective analyzing power of the polarimeter and the beam polarization. In this way GE,n could be determined with little model dependence and experimental uncertainties. The result GE,n(0.34GeV2/c2)=0.0611±0.0069stat({+0.0069}{−0.0055})syst is larger than previously assumed.
No description provided.
The measurement of the polarisation transfer to the proton in the reactions\(H(\vec e,e'\vec p)\) and\(D(\vec e,e'\vec p)\) performed with longitudinally polarised electrons in quasi-free kinematics is presented. The coincidence measurement was executed atQ2≈8fm−2 using the 855 MeV, c.w. beam of the Mainz Microtron MAMI. The recoil polarisation was determined by means of a carbon analyser. The experiment shows that the binding of the nucleon does not modify the polarisationPx of the recoil proton within an error ofΔPx/Px≈10%. The measured polarisation agrees with recent theoretical predictions. Implications for the measurement of the electric form factor of the neutron using the\(D(\vec e,e'\vec n)\) reaction are discussed.
No description provided.
The C12(γ,p)11B differential cross section has been measured over proton angles ranging from 58° to 128°, using tagged photons of energy 80–157 MeV, for low-lying regions of residual excitation energy in B11. The data have been compared with four different types of calculation. It is shown that scaling of the cross section with momentum mismatch occurs for both the ground-state and excited-state data.
EX IN 0 MEV REGION (FROM 0 TO 1.5 MEV). ANGULAR BINS OF 5 DEG WIDTH.
EX = 7 (FROM 6.5 TO 8.0 MEV). ANGULAR BINS OF 5 DEG WIDTH.
EX = 13 (FROM 12.0 TO 13.5 MEV). ANGULAR BINS OF 5 DEG WIDTH.
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