E. Calimani

CPT symmetry and neutral kaons

We discuss the accuracy of CPT invariance tests in the neutral kaon decays. The possible CPT non-invariance is parametrized by amplitudes of two types: (i) CP violating, but T conserving, and (ii) T violating, but CP conserving. It is shown that the experimental data are consistent with CPT symmetry essentially within two standard deviations. n nThe source of this not quite satisfactory agreement is the experimental value of the phase φ00 of the ratio A(KL0→π0π0)A(KS0→π0π0), which differs by two standard deviations from the phase φ+− of the ratio A(KL0→π+π−)A(KS0→π+π−) decay amplitude. We argue that to get better agreement with CPT invariance, the value of the phase φ00 has to be equal to the value of the phase φ+− within the errors of the latter. New, more accurate measurements of the phase φ00 would be very interesting to rest CPT invariance, especially taking into account that neutral kaons allow the test with much better accuracy than any other particle.

Measurement of the neutron and proton structure functions from neutrino and antineutrino scattering in deuterium

Abstract 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.

INCLUSIVE rho0 PRODUCTION IN anti-muon-neutrino D AND muon-neutrino D CHARGED CURRENT INTERACTIONS.

Abstract Inclusive production of the meson resonance ϱ0 in high-energy neutrino and antineutrino charged current (CC) interactions in deuterium was studied using the bubble chamber BEBC exposed to the CERN-SPS wide band neutrino and antineutrino beams. In a sample of 10693 charged current ν μ D and 13 758νμD interactions we found 0.222 ± 0.014ϱ0 per charged current event. Thr production of f mesons is smaller than 0.03 per CC event (90% confidence level). The ϱ0 production properties are studied in terms of charged hadron multiplicity, of the mass of the hadronic system and of various kinematical variables. The experimental results are compared with the predictions of the Lund fragmentation model, whose predictions are about 50% higher than the experimental values.

Fragmentation in neutrino and antineutrino charged current interactions on proton and neutron

AbstractSome experimental properties of the charged hadronic fragments are compared for νp, νn,n

Measurement of the νμ and νμ nucleon charged-current total cross sections, and the ratio of νμ neutron to νμ proton charged-current total cross sections

bar vp

Charged hadron multiplicities in high energy\(\bar v_\mu n\) and\(\bar v_\mu p\) interactions

n andn

Transverse momentum of charged hadrons produced in ν and\(\bar v\) deuterium charged current interactions

bar vn