A comparison of K±p and p±p elastic scattering is made for incident energy 50 to 175 GeV. Average values of 0.19±0.04 and 0.11±0.02 GeV2 were found for the invariant-momentum-transfer values of the Kp and pp crossover points, respectively.
KP AND PP CROSSOVER POINTS AT -T = 0.19 +- 0.04 AND 0.11 +- 0.02 GEV**2 (AVERAGE VALUES) RESPECTIVELY.
The differential cross sections for the elastic scattering of π+, π−, K+, K−, p, and p¯ on protons have been measured in the t interval -0.04 to -0.75 GeV2 at five momenta: 50, 70, 100, 140, and 175 GeV/c. The t distributions have been parametrized by the quadratic exponential form dσdt=Aexp(B|t|+C|t|2) and the energy dependence has been described in terms of a single-pole Regge model. The pp and K+p diffraction peaks are found to shrink with α′∼0.20 and ∼0.15 GeV−2, respectively. The p¯p diffraction peak is antishrinking while π±p and K−p are relatively energy-independent. Total elastic cross sections are calculated by integrating the differential cross sections. The rapid decline in σel observed at low energies has stopped and all six reactions approach relatively constant values of σel. The ratio of σelσtot approaches a constant value for all six reactions by 100 GeV, consistent with the predictions of the geometric-scaling hypothesis. This ratio is ∼0.18 for pp and p¯p, and ∼0.12-0.14 for π±p and K±p. A crossover is observed between K+p and K−p scattering at |t|∼0.19 GeV2, and between pp and p¯p at |t|∼0.11 GeV2. Inversion of the cross sections into impact-parameter space shows that protons are quite transparent to mesons even in head-on collisions. The probability for a meson to pass through a proton head-on without interaction inelastically is ∼20% while it is only ∼6% for an incident proton or antiproton. Finally, the results are compared with various quark-model predictions.
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The ratio of π+p to pp elastic scattering is found to be smoothly varying over the range −t=0.03 to 0.4 GeV2. It is well fitted by a single exponential, indicating the forward behavior must be quite similar for the two reactions.
ACTUALLY THE DATA ARE THE EXPONENTIAL SLOPE OF THE RATIO OF D(SIG)/DT FOR THE TWO REACTIONS.
We report final results on the polarization parameter P in elastic scattering of π − , K − and antiprotons at 40 GeV/ c incident momentum. The energy dependence of P (t) in π − p above 10 GeV/ c is well fitted by P (t) α s αR(t)-α P (t) where α R (t) are the effective Regge and Pomeron trajectories respectively. The data in K − p are compatible with exchange degeneracy. The results inp¯p show an important structure for |t|> 0.3 (GeV/c) 2 demonstrating the existence of a large helicity flip amplitude.
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We have measured the elastic cross section for pp, p¯p, π+p, π−p, K+p, and K−p scattering at incident momenta of 70, 100, 125, 150, 175, and 200 GeV/c. The range of the four-momentum transfer squared t varied with the beam momentum from 0.0016≤−t≤0.36 (GeV/c)2 at 200 GeV/c to 0.0018≤−t≤0.0625 (GeV/c)2 at 70 GeV/c. The conventional parametrization of the t dependence of the nuclear amplitude by a simple exponential in t was found to be inadequate. An excellent fit to the data was obtained by a parametrization motivated by the additive quark model. Using this parametrization we determined the ratio of the real to the imaginary part of the nuclear amplitude by the Coulomb-interference method.
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The polarization parameter P has been measured for elastic π + p, K + p and pp scattering at 45 GeV/c. Four-momentum transfer ranges from −0.08 to −1.1 (GeV/) 2 for pp, and from −0.08 to −0.9 (GeV/) 2 for π + p and K + p. The energy dependence of the polarization P ( t ) in π + p and in K + p above 6 GeV/c incident momentum is compatible with interference between pomeron and Regge poles. On the other hand, the polarization in p p elastic scattering decreases faster than ordinary Regge model predictions. This result can be explained by interference between non flip and flip amplitudes of the pomeron, leading to negative values for the polarization.
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1691 events were fitted to K - p elastic scatters at a K - momentum of 3.46 GeV/ c . The differential cross section as a function of 4 momentum transfer was fitted to exp ( A + Bt + Ct 2 ) with A = 3.7 B = 8.7 ( GeV / c ) −2 and C = 2.0 ( GeV / c ) −4 . The distribution is consistent with zero real part for the forward scattering amplitude.
D(SIG)/D(T) was fitted to EXP(CONST+SLOPE*T+SLOPE*T**2).
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The spin rotation parameter R has been measured for elastic π − p scattering at 40 GeV/ c , at four momentum transfers t ranging from −0.19 to −0.52 (GeV/ c ) 2 . The average value within this interval is R π − p = -0.200± 0.023. The resulting constraints on the πN scattering amplitudes are discussed. The experiments also yields an average value for K − p scattering, R K − p scattering, R K − p = -0.16±0.16.
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The polarization in π + p → π + p and K + p → K + p has been measured at 6 and 12 GeV/ c in the four-momentum transfer interval 0.1 ⩽ | t | ⩽ 2.0 (GeV/ c ) 2 by scattering on protons of a polarized deuteron target. Comparison with existing results obtained with polarized proton targets shows good general agreement and no evidence for asymmetry effects due to the presence of the spectator neutron. For K + p elastic scattering polarization the experiment yields improved statistics, especially at 6 GeV/ c
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