The differential cross section for elastic antiproton—proton scattering at s =1.8 TeV has been measured over the t range 0.034⩽| t |⩽0.65 (GeV/ c ) 2 . A logarithmic slope parameter, B , of 16.3±0.3 (GeV/ c ) −2 is obtained. In contrast to lower energy experiments, no change in slope is observed over this t range.
Numerical values from FERMILAB-FN-562 suppliedto us by R. Rubinstein. Statistical errors only. t values at centre of each bin.
Nuclear slope parameter. Error contains 0.3 GeV**-2 systematic uncertainty folded.
The high antiproton-proton luminosity obtained by using a target system consisting of a hydrogen gas-jet crossing a coasting beam of cooled antiproton circulating in one of the rings of CERN's ISR provides the possibility to measure low cross section reactions with very high precision. We present measurements of the antiproton-proton elastic cross section at 90° CM at incident momenta between 3.5 GeV/ c and 5.7 GeV/ c . The precision of these measurements is much higher than previously reported results. The data show that the cross section of this reaction decreases faster than s −12 over this momentum range.
No description provided.
No description provided.
The ratio of the real to the imaginary part of the pp forward elastic-scattering amplitude ϱ has been measured at 550, 757, and 1077 MeV/ c at LEAR, using the Coulomb-nuclear interference method. The results obtained for ρ and b , the nuclear slope, are ϱ = 0.084 ± 0.051 and b = 20.9 ± 2.1 (GeV/ c ) −2 at 550 MeV/ c , ϱ = 0.102 ± 0.043 and b = 18.0 ± 0.5 (GeV/ c ) −2 = at 757 MeV/ c , and ϱ = 0.059 ± 0.035 and b = 15.2 ± 0.3 (GeV/ c ) −2 at 1077 MeV/ c .
Error on SLOPE is statistical only.
Measured differential cross sections corrected for small-angle trigger efficiency and absorption losses. Statistical errors only.
Measured differential cross sections corrected for small-angle trigger efficiency and absorption losses. Statistical errors only.
We report results from a measurement of antiproton-proton and proton-proton small-angle elastic scattering at √ s = 24.3 GeV in the range 0.001 ⩽ | t | ⩽ 0.06 (GeV/ c ) 2 . The measurement was performed at the CERN p p Collider by using silicon detectors to observe protons recoiling from a hydrogen cluster-jet target intercepting the stored p and p beams. Fits to the measured differential cross sections yield the ratio of the real to the imaginary part of the forward nuclear scattering amplitude ρ and the nuclear slope parameter b for both p p and pp. We find that the difference Δρ = ρ ( p p ) − ρ( pp ) = 0.031 ± 0.010 agrees with conventional fits and disagrees with the “odderon” fit designed to accommodate the recent UA4 measurement of ρ( p p) at 546 GeV.
Data requested from authors.
No description provided.
Nuclear slopes fixed to world average.
Cross sections or upper limits are reported for 12 meson-baryon and two baryon-baryon reactions for an incident momentum of 9.9 GeV/c, near 90° c.m.: π±p→pπ±,pp±,π+°±,K+Σ±, (Λ0/Σ0)K0; K±p→pK±; p±p→pp. By studying the flavor dependence of the different reactions, we have been able to isolate the quark-interchange mechanism as dominant over gluon exchange and quark-antiquark annihilation.
No description provided.
No description provided.
Proton-antiproton elastic scattering was measured at the CERN SPS Collider at the centr-of-mass energy s =546 GeV in the Coulomb interference region. The data provide information on the phase of the hadronic amplitude in the forward direction. The conventional analysis gives for the ratio ϱ of the real to the imaginary part of the hadronic amplitude the result ϱ =0.24±0.04.
Axis error includes +- 0.025/0.025 contribution (Normalisation was fixed using a previous UA4 measurement of the total cross section: sig(name=tot)*(1 + alpha**2)).
Best estimate of alpha(rho).
Two high statistics measurements of antiproton-proton small-angle elastic scattering, at p = 233 MeV/ c and p = 272 MeV/ c , are presented. The measurements were carried out at the LEAR facility at CERN. By the Coulomb-nuclear interference method, values are obtained for the real-to-imaginary ratio ρ of the p̄p forward nuclear scattering amplitude and for its exponential slope b : ρ = + 0.041 ± 0.026 and b = 71.5 ± 4.5 (GeV/ c ) −2 at 233 MeV/ c and ρ = −0.014 ± 0.027 and b = 47.7 ± 2.7 (GeV/ c ) −2 at 272 MeV/ c . The method to derive these values is discussed in detail and so are the uncertainties contributing to their systematic error. The results are compared with predictions from forward dispersion relation calculations and with predictions from p̄p potential models.
The corrected cross section is the measured divided by the average folding correction given in the paper.
The corrected cross section is the measured divided by the average folding Correction given in the paper.
Fits to data use the value of total cross sections of 263 & 296 mb for 272 & 233 Mev respectively derived from the authors total cross sections measurement. ETA is the spin dependence parameter.
Proton-antiproton elastic scattering was measured at the centre-of-mass energy s = 630 GeV in the four-momentum transfer range 0.7 ⩽ − t ⩽ 2.2 GeV 2 . The new data confirm our previous results at s = 546 GeV on the presence of a break in the t -distribution at − t ≃ 0.9 GeV 2 which is followed by a shoulder, and extend the momentum transfer range to larger values. The t -dependence of the differential cross section beyond the break is discussed.
Errors contain statistics and acceptance uncertainty.
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INTEGRATED D(SIG)/D(T).
OBTAINED FROM FIT D(SIG)/D(T)=A*EXP(B*T+C*T**2) IN 0.05 < -T < 0.3.
Antiproton-proton and proton-proton small-angle elastic scattering was measured for centre-of-mass energies s =30.6, 52.8 and 62.3 GeV at the CERN Intersectung Storage Rings. In addition, proton-proton elastic scattering was measured at s =23.5 GeV . Using the optical theorem, total cross sections are obtained with an accuracy of about 0.5% for proton-proton scattering and about 1% for antiproton-proton scattering. The measurement of the interference of the Coulomb scattering and the hadronic scattering permits a determination of the ratio of the real-to-imaginary part of the forward hadronic scattering amplitude. Also presented are measurements of the hadronic slope parameter.
No description provided.
No description provided.
No description provided.
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