The reaction π − p → ω n has been studied at 8 and 12 GeV / c incident momenta with the CERN Omega spectrometer using a neutron time of flight trigger. The differential cross sections and the ω-decay density matrix elements are presented as functions of the momentum transfer squared − t in the range of 0.02 to 0.80 GeV 2 . The data are used to evaluate the intercept and slope of both the natural and unnatural parity exchange trajectories. Regge exchange amplitude factorisation tests involving the reaction π N → ω N are investigated.
No description provided.
'FIT'.
'FIT'.
The reaction K + p→ Δ ++ (1236)+ anything is studied at beam momenta 8.2 and 16 GeV/ c and compared with other Δ ++ producing reactions. We find that the low-mass Δ ++ π − enhancement affects the shapes of Δ ++ inclusive distributions. The triple-Regge formula is found to be consistent with the data. Dual properties of this formula are successfully tested.
No description provided.
No description provided.
No description provided.
The momentum transfer (t′) dependence of the JP=1+K*π and ρK partial waves in the K±π+π− system is presented. The production of the Q1 meson (m∼1300 MeV), which has a large ρK decay mode, obeys approximate s-channel helicity conservation. In contrast the production of the Q2 meson (m∼1400 MeV), which decays predominantly to K*π, satisfies approximate t-channel helicity conservation. Furthermore the Q1 production distributions are virtually identical, whereas the Q2± distributions exhibit a distinct cross-over for |t′|∼0.18 GeV2.
No description provided.
In view of the possible production of heavy leptons or charmed states in e+e− collisions, we searched for anomalous muons with momenta pμ≳1 GeV/c. The inclusive cross section for nch>~3 has an upper limit of 96 pb (assuming isotropy). For nch=2 and noncoplanarity > 20°, an excess of muonic events is observed, corresponding to (dσdΩ)|90°=23−9+12 pb/sr; the probability that known processes produce the observed events is 2×10−4.
No description provided.
We present results of a K − d experiment performed with the 81 cm Saclay deuterium bubble chamber which was exposed to a K − beam at 4 momenta between 680 and 840 MeV/ c at the CERN PS. Cross sections were measured for inelastic two- and three-body K − n reactions on the basis of 5200 events/mb. Resonance production in the three-body reactions is discussed. In addition, differential cross sections and polarisations are presented for inelastic two-body reactions.
CROSS SECTIONS FOR TWO-BODY REACTIONS.
CROSS SECTIONS FOR THREE-BODY REACTIONS.
CROSS SECTIONS FOR K- P REACTIONS.
The inclusive production of π and η mesons at 90° from proton-proton collisions has been measured at the CERN ISR at centre-of-mass energies between 23.5 and 62.4 GeV. The momentum correlation of charged particles emitted together with a large transverse momentum pion has also been studied, using two magnetic spectrometers each centred at 90°.
No description provided.
No description provided.
No description provided.
Measurements have been made of the differential cross section for p p elastic scattering over a c.m. angular range −0.95 ⩽ cos θ ∗ ⩽ 0.93 at 21 incident antiproton momenta between 0.69 GeV/ c and 2.43 GeV/ c (c.m. energy 1.96–2.58 GeV). About 10 5 events were obtained at each momentum. The results are discussed primarily in terms of the formation of s -channel resonances in the T and U mass regions, and within the context of the optical model of Frahn and Venter.
No description provided.
No description provided.
No description provided.
The differential cross section of K − p and K + p elastic scattering has been measured at 4.2, 7 and 10 GeV/ c in the very forward region of scattering angles. The measurements have been made at the CERN PS by means of multiwire proportional chambers and counters. The region of momentum transfers t is 0.001 ⩽ | t | ⩽ 0.10 GeV 2 at the highest momentum and 0.001 ⩽ | t | ⩽ 0.03 GeV 2 at the lowest. Over these regions the Coulomb and the nuclear amplitudes reach their maximum interference. We have used a parametrisation of the above amplitudes to determine the value of the real part of the nuclear forward scattering amplitude. A dispersion relation fit has then been performed using these and earlier measurements; the asymptotic behaviour of the K ± p real parts has been examined in the light of this fit.
No description provided.
No description provided.
No description provided.
The reaction p p → K ∗ K does not exhibit any s -channel resonance effect between 1 and 2.5 GeV/ c . On the contrary, the data on p p → K ∗∓ K ± are compatible with an exchange mechanism in the t - and u -channels above 1.5 GeV/ c . Strong similarities are found with p p → K − K + and K ∗− K ∗+ . The polarisation of K ∗± is given. The reaction p p → K ∗0 K 0 vanishes above 1.5 GeV/ c
No description provided.
LEG(L=0) = SIG/(4*PI).
LEG(L=0) = SIG/(4*PI).
From 63 760 four pronged events we have selected 10 960 events of the p p π + π − final state. We have studied baryon resonances production and the associated production of Δ(1236) Δ (1236) isobars. We find (48.5 ± 2.6)% of Δ ++ Δ ++ and (4.5 ± 0.5)% of Δ 0 Δ 0 . Study of the various mass spectra shows that they are essentially described by the introduction of Δ ++ ( Δ ++ ) production. Introduction of the strong t dependence of the Δ ++ ( Δ ++ ) changes this description only slightly. A study of the interaction radius of the p π system reveals a best value of r = 1.6 ± 0.4 fm. Bumps observed in the p π + π − + c.c. system at 1450 and 1690 MeV when treated as resonances give rates of (4.0 ± 0.4)% and (4.5 ± 0.4)% respectively. We arrive at the conclusion that the reaction p p → p p π + π − at 5.7 GeV/ c proceeds almost entirely via the production of baryon resonances.
No description provided.
No description provided.
Forum