Systematic study ofπ±p,K±p,

I. Ambats

¹

,

D. S. Ayres

²

,

R. Diebold

³

et al.

Abstract

3~o t hMonte Carlo-generated events for particular reactions a s well a s the real data, where it is possible to check this, indicate that there is little difference, generally less than 0.5 units, between 17 and the real longitudinal rapidity y = 4 ln[(E +p , , ) / ( E -prl)l.2"he different shapes of the data near v = 0 and near v = -6 result from the use of the pseudorapidity and the angle errors on the fast forward tracks.Measurements of ntp, K*p, pp, andpp elastic scattering a r e presented for incident momenta of 3, 3.65, 5, and 6 GeV/c and momentum transfers typically 0.03 to 1.8 Gev2. The q l e and momentum of the scattered particle were measured with the Argonne Effective Mass Spectrometer for 300 000 events, yielding 930 cross-section values with an uncertainty in absolute normalization of k4 %. Only the K + and proton data show any significant change in slope of the forward diffraction peak with incident momentum. The particle-antiparticle crossover positions are consistent with no energy dependence, average values being 0.14 10.03, 0.19010.006, and 0.162 +0.004 G~V ' for n's, K ' s , and protons, respectively; these e r r o r s reflect both statistics and the *1.5 % uncertainty in particle-antiparticle relative normalization. Differences between particle and antiparticle cross sections isolate interference terms between amplitudes of opposite C parity in the t channel; these differences indicate that the imaginary part of the odd-C nonflip-helicity amplitude has a ~~(r(-t)"') structure for -t ~0 . 8 Gev2, as predicted by strong absorption models. The cross-section differences for K * and proton-antiproton a r e in qualitative agreement with the predictions of w universality, the agreement improving with increasing energy. The corresponding quark-model predictions relating the n* and K* differences failed by more than a factor of 2. We have combined our r * cross sections with other data to better determine the nN amplitudes in a model-independent way; results of this analysis a r e presented.

Absolute measurement of the differential cross section for pp elastic scattering at ANKE-COSY

“…1, our data fall about 25% below the SAID predictions at 2.65 GeV and a similar disagreement is found with the results of Ref. [9] at the slightly higher energy of 2.83 GeV. The variation of the discrepancy with energy is illustrated in the right panel of Fig.…”

“…The curve is the SP07 solution from the SAID analysis group [5] and the crosses are experimental data at 2.83 GeV taken from Ref. [9]. Right: Average ratio of experimental data on the pp elastic differential cross section to the SAID predictions [5] for 10 • < θ cm < 30 • for different energies.…”

Toward complete pion nucleon amplitudes

“…6 for p lab ≥ 50 GeV. In the fit we use the data from [33][34][35]. The value of the parameters is given in columns three and four in Table I.…”

Study ofπ−C→π+π−Ascoli1, Chapin2, Cutler3 et al. 1973Phys. Rev. Lett.7000View full textAdd to dashboardCite

“…5 This point is discussed in more detail in Ref. 4 state is identified by its y decay to the ground state of carbon. This technique was applied in the present experiment to the production of three pions in coincidence with a 4.44-MeV y ray.…”

“…128, 2425 (1962), and Theoretical Physics (International Atomic Energy Agency, Vienna, 1963), p. 89. 4 A. Casher, J. Kogut, and L. Susskind, to be published. 5 This point is discussed in more detail in Ref.…”