In an experiment with the CERN 2m deuterium bubble chamber the reaction K + d→K o pp (1) and the related reaction K + n→K o p (2) are studied at an incident momentum of 4.6 GeV/ c . The cross section for the latter reaction is found to be slightly larger than the cross section for the reaction K − p → K o n at the same energy. The corresponding differential cross sections agree within the rather large uncertainties. The forward amplitude for reaction (2) is predominantly real. Moreover, the total and forward differential charge exchange cross section values are compatible with those predicted on the basis of an SU (3) sum rule. A comparison of the K ± -charge exchange differential cross sections with the predictions of a Regge pole model is also presented.
No description provided.
SMALL -T DEUTERIUM CORRECTION APPLIED USING MC GEE WAVE FUNCTION (PAPER ALSO GIVES UNCORRECTED AND HULTHEN CORRECTED DATA).
The differential cross section has been measured using 940 events from the BNL 30-inch deuterium bubble chamber. Events were selected without regard to length of the deuteron, and so wide-angle scatters are included. The data are fitted well by a Glauber model with reasonable assumptions about the parameters.
No description provided.
INTEGRATED CROSS SECTION USING EXPONENTIAL FIT TO FORWARD PEAK (SLOPE = 25.2 +- 1.4 GEV**-2).
We have studied the K ππ system in the 14.3 GeV/ c reactions K − p → K − π + π − p, K − p → K 0 π − π 0 and K − p → K 0 π + π − n . The data have been obtained from a 500 000 picture exposure of the CERN 2m HBC. The first two final states are dominated by Q-production in the Kππ system; there is also an L-signal at M (K ππ ) ∼ 1.75 GeV. The reaction cross sections are compared to K − p data at other energies. We discuss the K ππ mass dependence of the diffractive production slope. Evidence is presented for a Q − p versus Q + p differential cross section cross-over around | t | = 0.17 GeV 2 . A t -channel isospin analysis for the KN → K ∗(890)π N channels in the Q-region shows that the I = 1 exchange amplitude is ⋍ 10% of the dominant I = 0 exchange amplitude. The K ππ decay distributions indicate a predominant J P = 1 + state in the Q-region, and an important J P = 2 − contribution in the L-region. We find neither s -channel nor t -channel helicity conservation at the meson vertex in the Q- or L-regions. The K π angular correlation moments within the K ππ diffractive system are characteristic of K π elastic scattering, suggesting a π -exchange Deck-type production mechanism. There is evidence for a Kf 0 and κπ contribution (where κ is the J P (K π ) = 0 + state) to the diffractive K ππ system. A fit to the K − π + π − and K 0 π − π 0 Dalitz-plot distributions for the Q-re gion indicates that the ratio of K ϱ to K ∗ π decay amplitudes decreases with increasing K ππ mass.
No description provided.
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.
The reaction γp→; π + π − p in the energy range 4.1 to 6.2 GeV has been studied with a tagged photon beam incident on a liquid hydrogen target in the DESY one-meter streamer chamber. The reaction is analysed in terms of the longitudinal phase space (LPS) method. The one-pion-exchange model for Δ(1236) production and decay is examined. For the diffractive part of the LPS a dual model with pomeron exchange is investigated. In particular, the s -channel helicity conservation dual model of Dewey and Humpert describes the data well.
No description provided.
CORRECTED FOR LOSSES AT SMALL T (UNLIKE VALUES OF 'REF 1'). BACKGROUND SUBTRACTION ERROR HAS BEEN ADDED QUADRATICALLY TO THE STATISTICAL ERROR.
No description provided.
The differential cross sections for the reaction γ + n → π 0 + n have been measured at pions angles of 45°, 60°, 105°, 120° and 140° in the c.m.s. for photon energies of 500–900 MeV. Both π 0 meson and recoil neutron from a liquid deuterium target were detected with a pair of Čerenkov counters combined with lead spark chambers and a hodoscope consisting of 16 modules of plastic scintillation counters.
We have made a study of the coherent reaction K + d → K 0 π + d at 2 GeV/ c , using data obtained in the Lawrence Berkeley Laboratory 25 inch bubble chamber. The cross section for this reaction is 324 ± 25 μ b, after correction for invisible K 0 decays. This reaction is dominated primarily by vector exchange. We determine the parameters of the ω trajectory to be α ω = (0.33 ± 0.04) + t .
No description provided.
SLOPE IS 9.4 +- 0.5 GEV**-2 FOR -T > 0.02 GEV**2 AND 10.4 +- 0.6 GEV**-2 FOR -TP > 0.
No description provided.
The average multiplicities 〈 n c 〉 and 〈n〉, of charged-plus-neutral pions produced in e + e − collisions, have been determined for total center-of-mass energies ranging from 1.2 to 2.4 GeV. No appreciable multiplicity variation is observed over this energy range, where the mean values 〈; n c 〉 = 3.3 +0.3 −0.2 and 〈 n 〉 = 4.4 +0.4 −0.2 are found.
No description provided.
VALUES OF R CALCULATED FROM TOTAL CROSS SECTION.
We have measured dσ du for π − p elastic scattering at 3 and 4 GeV c in the ranges −0.119⩽ u ⩽0.113 and −0.233⩽ u ⩽0.088, respectively. A fit of the form d σ /d u = A exp ( Bu + Cu 2 ) gives B = 4.34±0.42 and C = 7.0±3.5 at 4 GeV c with χ 2 = 5.7 for 9 degrees of freedom; the simpler form d σ /d u = A exp( Bu ) gives B = 3.7 ± 0.3 with χ 2 = 9.6. At 3 GeV c we confirm with high statistics the structures already observed.
No description provided.
No description provided.
Results are presented on an analysis of the reaction K + p → K ∗+ (890) p at 16 GeV/ c and compared with data at lower incident momenta and with corresponding results for the reaction K − p → K ∗− (890) p. It is found for both reactions that the energy dependence of the cross section exhibits a simple ( p − n lab behaviour.
BREIT-WIGNER RESONANCE FITS WITH BACKGROUND.
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