12,100 νD and 10,500\(\bar vD\) charged current interactions in deuterium measured in the BEBC bubble chamber were used to obtain the complete set of structure functions of proton and neutron. Thex andQ2 dependence of the structure functions of up and down valence quarks and antiquarks are presented and discussed. The Adler and Gross-Llewellyn Smith sum rules have been tested at differentQ2 values. A QCD analysis of the four non singlet structure functionsxF3νN,xuv,xdv andF2νn−F2νp has been performed yielding values ofΛLO between 100 and 300 MeV.
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We report the observation of 21 dimuon events at the CERN p p Collider with the UA1 detector. The events range in invariant dimuon mass from 2 to 22 GeV / c 2 . The properties of these events are given. The bulk of the events are consistent with heavy-flavour production (mainly b b ) with a few candidates for Drell-Yan production. There remain a few events which are difficult to interpret in terms of these processes, in particular two events with isolated, like-sign muons.
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We report evidence for the production of the charged D ∗ mesons in pp̄ collisions at s = 540 GeV . The search was confined to the charged particle fragments of hadronic jets, which are expected to be predominantly gluon jets in this experiment. The fragmentation function and production rate for D ∗ in jets of average transverse momentum of 28 GeV/ c are given.
THE D*'S ARE CONSIDERED AS ARISING ONLY FROM FRAGMENTATION OF HADRONIC JETS ('GLUON' JETS). HERE THE <PT> OF THE JET IS AROUND 28 GEV THE DEFINITION OF Z IS P(D*).P(JET)/(P(JET))**2.
Antineutrino interactions in BEBC are compared to look for differences between the differential cross sections per nucleon in neon and in deuterium. The identical geometries, beam spectra and muon identification criteria and acceptances allow comparison with very small systematic errors. The results are compared in detail with μ and e scattering data from EMC and SLAC. We find no rise in the ratio d σ/ d x ( ν Ne )/σ/ d x ( ν D 2 ) at low x , independent of Q 2 up to Q 2 ∼ 14 GeV 2 .
VALUES OF Q**2 IN THIS TABLE ARE :- 1.07,2.59,4.33,6.14,7.67,8.28,6.35 (FOR ALL Q**2) AND :-,7.9,9.5,11.5,13.2,13.9,11.6 (FOR Q**2 > 4.5 ).
Some experimental properties of the charged hadronic fragments are compared for νp, νn,\(\bar vp\) and\(\bar vn\) interactions: multiplicities of forward and backward going particles,xF distributions for pions, fragmentation functions and theirQ2 andW2 dependence. The results are compared with the predictions of the Lund fragmentation model.
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The two-jet cross section measured in the UA1 apparatus at the CERN p p Collider has been analysed in terms of the centre-of-mass scattering angle θ and the scaled longitudinal parton momenta x 1 and x 2 . The angular distribution d σ /d cos σ rises rapidly as cos → 1, independent of x 2 and x 2 , as expected in vector gluon theories (QCD). The differential cross section in x 1 and x 2 is consistent with factorization and provides a measurement of the proton structure function F(x) = G(x) + 4 9 [Q(x) + Q (x)] at values of the four-momentum transfer squared, -t̂ ≈ 2000 GeV 2 . Over the range x = 0.10−0.80 the structure function shows an exponential x dependence and may be parametrized by the form F ( x ) = 6.2 exp (−9.5 x ).
S(X1,X2) IS DEFINED BY X1*X2*D2(SIG)/DX1/DX2 NORMAISED APPROPRIATELY.
F(X) DEFINED AS G(X)+(4/9)*(Q(X)+QBAR(X)).
Muons of high transverse momentum p μ T have been observed in the large drift chambers surrounding the UA1 detector at the CERN 540 GeV pp̄ collider. For an integrated luminosity of 108 nb −1 , 14 isolated muons have been found with p T > 15 GeV/ c . They are correlated with a large imbalance in total transverse energy, and show a kinematic behaviour consistent with the muonic decay of the Intermediate Vector Boson W ± of weak interactions. The partial cross section is in agreement with previous measurements for electronic decays and with muon-electron universality. The W mass is determined to be m W = 81 +6 −7 GeV/ c 2 .
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Data from an exposure of the BEBC bubble chamber filled with deuterium to neutrino and antineutrino wide band beams have been used to extract the x dependence of the structure functions for scattering on protons and neutrons and the fractional momentum distributions of the valence quarks and the antiquarks of different flavours. The difference F n 2 − F p 2 is compared with recent data from high energy μD scattering. A result is also obtained on the sum rule giving the difference between the number of up and down quarks in the nucleon.
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A sample of 52 Intermediate Vector Boson decays in the ( v e e) channel is described. They were produced at the CERN SPS Collider for an integrated luminosity of 0.136 pb −1 . Both production and decay properties fit well with expectations from the Standard Model of weak interactions. An improved value for the W mass is given and compared with the previously published value for the Z 0 mass.
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We have measured neutral and charged current interactions of ν μ and ν μ on proton and neutron. From a combination of ratios we determine the neutral current chiral coupling constants. The results are u 2 L = 0.13 ± 0.03, d 2 L = 0.19 ± 0.03, u 2 R = 0.02 ± 0.02 and d 2 R = 0.00 ± 0.02. These results agree with the predictions of the standard SU(2) × U(1) model. The corresponding value of sin 2 θ W is 0.20 ± 0.04.
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