The x dependence of the longitudinal structure function F L was determined with the CHARM neutrino detector exposed to neutrino and antineutrino wide-band beams of the CERN 400 GeV SPS. The results show a clear deviation from the Callan-Gross relation. The amount and the x dependence of this deviation are in agreement with the contribution coming from a finite transverse momentum of the partons in the nucleon if both the intrinsc and perturbative QCD terms are taken into account.
VALUES OF Q**2 FOR EACH POINT IN THE TABLE ARE:- 0.76,3.0,9.3,16.6,18.9.
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.
e + e − annihilation into hadrons was studied at CM energies between 39.8 and 45.2 GeV and a search was made for new heavy quarks. No evidence was found for the existence of a narrow state excluding the possible existence of the lowest vector toponium state in this mass range. A search for continuum production of heavy quarks led to lower mass limits for new quarks of 22.0 GeV ( e Q = 2 3 ) and 21.0 GeV ( e Q = 1 3 ). Quarks are found to be pointlike, the corresponding mass parameter being larger than 288 GeV. A fit of the QCD and the electroweak contributions to R = σ tot / σ μμ yielded sin 2 θ W = 0.30 −0.07 +0.23 .
STATISTICAL ERRORS ONLY. NUMERICAL VALUES OF DATA TAKEN FROM PREPRINT.
No description provided.
No description provided.
Reconstruction of charged D ∗ 's produced inclusively in e + e −. annihilation at CM energies near 34.4 GeV is accomplished in the decay modes D ∗ + → D 0 π + → K − gp + π 0 π + and D ∗ + → D 0 π + → K − gp + π − π + π + and their charge conjugates. Using these and previously reported D ∗ + → D 0 π + → K − gp + π + and D ∗ + → D 0 π + → K − gp + π + + missing π 0 channels we present evidence for hard gluon bremsstrahlung from charm quarks and show that the ratio of the quark-gluon coupling constant of charm quarks to the coupling constant obtained in the average hadronic event, α s c α rms = 100 ± 0.20 ± 1.20 . Our result provides evidence that the quark-gluon coupling constant is independent of flavor.
No description provided.
No description provided.
No description provided.
Inclusive and semi-inclusive cross sections and distributions of γ's and π0's inK+p interactions at 70 GeV/c are presented. The results are compared to other experiments and to the Lund model for low-pT hadron collisions.
No description provided.
No description provided.
No description provided.
Results are presented of a measurement of the proton-proton elastic-scattering spin parameter CLL=(L,L;0,0) at 11.75 GeV/c and θc.m.=48°−90°. The value of CLL is nearly constant and is approximately -0.16 in this angular region. This behavior is consistent with only one of the many models proposed describing the interaction via the hard scattering of two quarks.
NUMERICAL VALUES OF DATA SUPPLIED BY H. SPINKA.
ESTIMATED VALUE OF CSS (90 DEG) DETERMINED FROM PRESENT DATA ON CLL AND DATA OF CRABB ET AL., (PRL 41, 1257) AND CROSBIE ET AL., (PR D23, 600) FOR CNN VIA THE RELATION CNN-CSS-CLL=1 (90 DEG). ERROR CONTAINS BOTH SYSTEMAT8ICS AND STATISTICS.
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.
Distributions of the Bjorken scaling variables x and y, and the structure function F+(x), are presented both for neutral-current and for charged-current νμ interactions. The data were obtained by use of the Fermilab 15-ft neon bubble chamber exposed to a narrow-band νμ beam. Results are based on 151 neutral-current and 683 charged-current events. An important feature of the neutral-current analysis is the event-by-event reconstruction of the outgoing neutrino.
No description provided.
DATA REQUESTED FROM C.BALTAY ON 20/9/91.
DATA REQUESTED FROM C.BALTAY ON 20/9/91.
The production of very large transverse momentum hadron jets has been measured in the UA2 experiment at the CERN p p Collider for s = 540 GeV using a highly segmented calorimeter. The range of previously available cross sections for inclusive jet production is extended to p T = 150 GeV and the two-jet invariant mass distribution to m jj = 280 GeV with the largely increased data sample collected during the 1983 running period. The results are compared with the predictions of QCD models.
LISTED ERRORS INCLUDE STATISTICAL AND THE PT-DEPENDENT UNCERTAINTIES. THE ADDITIONAL OVERALL SYSTEMATIC UNCERTAINTY IS 45PCT.
LISTED ERRORS INCLUDE STATISTICAL AND THE M-DEPENDENT UNCERTAINTIES. THE ADDITIONAL OVERALL SYSTEMATIC UNCERTAINTY IS 45PCT.
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