Measurements are reported of p̄p total cross sections from 388 to 599 MeV/ c in small momentum steps. Statistical errors are typically ±0.4%and the normalisation uncertainty is ±0.7%. There is no evidence for the “S-meson”.
DATA TAKEN WITH 8.33 CM LH2 TARGET.
DATA TAKEN WITH 1.17 CM LH2 TARGET.
The depolarization parameter D NN for pp elastic scattering at θ cm = 90 ° has been measured at twelve momenta between 0.9 and 1.5 GeV/ c . The moduli of the three transversity amplitudes T 1 , T 3 , and T 4 have been extracted from these data and from previous measurements of the differential cross section and spin correlation parameter A NN (90 °). Smooth energy dependence is found for all three amplitude moduli.
Axis error includes +- 3/3 contribution (DUE TO UNCERTAINTIES IN THE TARGET ANALYSING POWER).
An exposure of BEBC equipped with the hydrogen-filled TST to the v μ wide band beam at the CERN SPS has been used to study v μ interactions on free protons. About neutral induced interactions have been observed inside the hydrogen and separated into charged current, neutral current and neutral hadron interactions using a multivariate discriminant analysis based on the kinematics of the events. The neutral to charged current cross-section ratio has been determined to be R p v = 0.33 ± 0.04 . When combined with the value of R p v previously determined in the same experiment, the result is compatible with the prediction of the standard SU (2) × U (1) model for sin 2 θ W = 0.24 −0.08 +0.06 and ρ = 1.07 −0.08 +0.06 . Fixing the parameter ρ = 1 yields sin 2 θ W = 0.18 ± 0.04.
No description provided.
We present new measurements of parity conservation in the 293-nm transition in atomic Tl81205. Linearly polarized 293-nm photons, polarization ε^, are absorbed by 6P122 atoms in crossed electric and magnetic fields. The transition probability for each Zeeman component contains a term proportional to ε^·B→ε^·E→×B→ arising from interference between the Stark E1 amplitude βE and the parity-nonconserving E1 amplitude Ep. Our result, [ImEpβ]expt=−1.73±0.33 mV/cm, is compared with estimates based on the standard electroweak model.
Spin of the Tl nucleus is 1/2.
The differential cross sections of the reaction p―p→n―n were measured at 390, 490, 590, 690, and 780 MeV/c. The existence of the theoretically predicted forward dip is confirmed. The results are compared with the predictions of various N―N potential models.
NUMERICAL VALUES SUPPLIED BY F. SAI.
NUMERICAL VALUES SUPPLIED BY F. SAI.
NUMERICAL VALUES SUPPLIED BY F. SAI.
The electroweak production asymmetry and the decay fragmentation function for e + e − → c c have been measured at s = 29 GeV using charged D ∗ production over the full kinematic range. The data were taken at PEP using the High Resolution Spectrometer. The measured asymmetry is −0.12 ± 0.08. The total production cross section in units of the point cross section corrected for initial state radiation is R D ∗ = 2.7 ± 0.9 .
ASSUMES SIG(D*+) = SIG(D*0). (EXPT. MEASURES D*+ PRODUCTION ONLY). R VALUE CORRECTED FOR INITIAL STATE RADIATION.
No description provided.
We have observed inclusive production of D0 and D+ mesons, and their charge conjugates, in e+e− annihilation at 29 GeV on the basis of a data sample of 106 pb−1. These signals correspond to R values of R(D0+D―0)=1.8±0.5 and R(D++D−)=1.2±0.4. Taking the D+ and D0 data together, we measure a charge asymmetry of A=−0.08±0.12 for charmed quarks. A comparison of R(D+D―) with R(D*+D―*) obtained via the process D*+→D0π+ gives a DD* ratio of 1.0−0.2+0.3, indicating that direct D* production dominates over direct D production.
No description provided.
EXTRAPOLATED TO ALL Z.
No description provided.
Total inclusive cross sections for rho0, ω and f (1270) meson production and the corresponding average multiplicities < n(rho0) > = 0.072+-0.019, < n(ω) > = 0.033+-0.022, < n(f) > = 0 01 +-0.010 have been measured in π-C interactions at 5 GeV/c. It is shown that approximately 8 percent of secondary π- mesons are produced from the meson resonance decay. For the reactions with the production of rho0 mesons the dependence of the inclusive differential cross sections on the rapidity and squared transverse momentum is analysed
No description provided.
No description provided.
Sixty-two charm events have been observed in an exposure of the SLAC Hybrid Facility toa backward sacttered laser beam. Based on 22 neutral and 21 charged decays we have measured the charmed-meson lifetimes to be τD0=(6.8−1.8+2.3)×10−13 sec, τD±=(7.4−2.0+2.3)×10−13 sec and their ratio τD±τD0=1.1−0.3+0.6. The inclusive charm cross section at a photon energy of 20 GeV has been measured to be 56−23+24 nb. Evidence is presented for a non-DD¯ component to charm production, consistent with (35±20)% Λc+ production and some D*± production. We have found no unambiguous F decays.
No description provided.
The inclusive production of charmed baryonsΛc+ by 40–70 GeV neutrons on carbon has been observed. The decays\(\Lambda _c^ + \to \bar K^0 p\pi ^ + \pi ^ -\) (130 ± 18 events) andΛc+→Λ0π+π+π− (57±14 events) have been detected. The mean value ofΛc+ mass is (2,268±6) MeV/c2. The invariant cross section forX>0.5 is described byE·d3σ/dp3∝ exp(−)bPT·(1−X)n withb=(2.5±0.6) (GeV/c)−1 andn=(1.5±0.5).
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