The differential cross section for the reaction π − p→n π ° has been measured with high statistics at six incident beam momenta between 1.0 and 2.4 GeV/ c . The results are compared with predictions of recent phase shift analyses and forward dispersion relations.
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FROM EXTRAPOLATING THE LEGENDRE POLYNOMIAL FITS.
THE LEGENDRE POLYNOMIAL FITS WERE CONSTRAINED IN THE EXTREME BACKWARD DIRECTION BY DATA AT THETA = 180 DEG FROM OTHER EXPERIMENTS.
In this note we report the results obtained in a single-photoproduction experiment on neutrons in deuterium, with an experimental apparatus made of scintillation counters, spark chambers and a magnetic spectrometer; the explored energy region is one around the second resonance, that is (500÷900) MeV indicent γ-ray energy. We briefly describe the present situation of the phenomenological analysis of the single photoproduction in the second resonance region and compare the results of an analysis made by us with the results obtained by other authors; in particular the e.m. coupling of theP11 isobaric state found by us is large, in accordance with the results of some other authors.
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Experimental results are presented for the available channels in the 1.2 GeV/ c π + p interaction. An isobaric model with incoherent addition of the amplitudes is used to determine the π, Δ and N ∗ abundance rates in the π + π o p final state. The multipole parameters in the density matrix of the Δ ++ are determined as functions of its production angle.
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LEGENDRE POLYNOMIAL FIT USED TO CORRECT FOR ELASTIC EVENTS LOST FROM THE FORWARD BIN.
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The π−+p→π0+n differential cross section at 180° has been measured for 52 values of π− momentum from 1.8 to 6.0 GeV/c using a constant-geometry detection system. The average statistical uncertainty is ∼5% and the systematic uncertainty is ∼10%. The details of the experiment and the data analysis are discussed. The data are compared with those of other experiments with which they are generally in agreement. One set of data disagrees with those presented here and a possible reason for this is discussed. A five-parameter fit of the predictions of a dual-resonance model to our data gave excellent agreement. The differential cross sections at 180° for π±p elastic scattering have been compiled and the moduli and relative phase of the T=12 and T=32 pion-nucleon s- and u-channel amplitudes (|A12|, |A32|, and cosδ) have a minimum at u=0.4 GeV/c and, in the s channel, a corresponding minimum at s=2.2 GeV/c.
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The ratio R = (d σ /d t )( γ d → ( π 0 n)p)/(d σ /d t )( γ d → ( π 0 p)n), was measured at the Deutsches Elektronen-Synchrotron DESY, Hamburg at a mean photon energy of 4.0 GeV in the four-momentum transfer range between t = − 0.2 (GeV/ c ) 2 and t = − 1.2 (GeV/ c ) 2 in steps of approximately 0.08 (GeV/ c ) 2 . The ratio R is less than 1 up to t = − 0.9 (GeV/ c ) 2 and shows a broad minimum around t = − 0.6 (GeV/ c ) 2 . Corrections for nuclear effects in the deuterium were not applied but are shown to be small.
No description provided.
We have studied high-energy proton scattering on Be, C, Cu and Pb targets using a single-arm spectrometer. The projectile momenta were 19 and 24 GeV/ c , the square of the four-momentum transfer varied from t = 0.1 to t = 4.4 GeV 2 . We have recorded momentum distributions of scattered protons in the high-momentum range. An application of multiple-scattering theory yielded agreement of calculation and experimental results to within a ± 30% uncertainty of the former.
X ERROR D(OMEGA) = 0.0076 MSR.
X ERROR D(OMEGA) = 0.0076 MSR.
X ERROR D(OMEGA) = 0.0076 MSR.
We present experimental results on the K + n → K + n differential cross sections measured in deuterium at 13 momenta between 0.64 and 1.51 GeV/ c .
REACTION HAS A SPECTATOR PROTON. WHILE SOME DEUTERIUM CORRECTIONS HAVE BEEN APPLIED, THESE DATA ARE NOT DIVIDED BY THE DEUTERIUM FORM FACTOR APPEARING IN THE IMPULSE APPROXIMATION.
Based on 150 000 photographs taken at the ZGS with the 30 inch deuterium-filled chamber we present an analysis of the elastic p d scattering reaction. Due to unrecoreded small deuteron recoils we were only able to measure the elastic cross section in the four-momentum region | t | > 0.03 (GeV/ c ) 2 . Extrapolation towards small | t | by two different methods gave us two compatible estimates of the total elastic cross section. The differential cross section was analyzed by means of the Glauber formalism both with and without the effects due to the D-wave part of the deuteron wave function. The differential cross sections of np at 5.4 GeV/ c and pn deduced from our data were compared and exhibit a crossover phenomenon.
CALCULATED USING TOTAL ELASTIC SIG(-T > 0.03 GEV**2) = 7.2 +- 0.4. THE SMALL ANGLE SCATTERING APPROXIMATION HOLDS: D(SIG)/DOMEGA(RF=LAB) = (P**2/PI)*D(SIG)/DT.
INTEGRATED CROSS SECTION USING EITHER EXPONENTIAL EXTRAPOLATION OR GLAUBER MODEL FIT FOR -T < 0.03 GEV**2.
The differential cross section for the reaction γp → π 0 p at forward angles has been measured in the energy region between 350 MeV and 1175 MeV. A phenomenological multiple analysis was carried out on the present data together with other data.
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We have determined the pion charge exchange cross section on hydrogen for π ° mesons emitted at 180° by measuring neutron time-of-flight. Using known values of the p-wave phase shifts we have deduced the contribution of the s-wave. We obtain a value for the quantity a 1 − a 3 (in h = c = m =1 units where m is the pion mass) =0.270±0.014 in agreement within the errors with recent theoretical calculations. We also find a value of 114±55 μb / sr for the cross section in the center of mass system for radiative pion capture at 22.6 MeV (gamma ray emitted at 180°).
No description provided.
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