Charged pion production in 32GeV/c K+p interactions

Final data on topological cross sections are presented. Inclusive single particle distributions for the reactions K+p→ π±X at 32 GeV/c are discussed and compared with data at lower energies. Early scaling in the fragmentation regions is confirmed, while cross sections in th central region continue to rise with energy even faster than in pp interactions. The x-and pT-dependence of the π+/π- ratio in K+p interactions is discussed and a comparison of reactions K+p→ π±X and K-p→ π±X at 32 GeV/c is made in the context of constituent models. We also present transverse momentum distributions, show prominent seagull effects and study how they are influenced by resonance production. © 1980 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Observation in K+p interactions at 32 GeV/c of a narrow state at 2145 MeV/c2 decaying into øπ+

We present evidence for a new narrow state decaying into øπ+ with a mass of 2145 ± 10 MeV/c2 and an experimental width of 25 MeV/c2, produced in K+p interactions at 32 GeV/c. The production cross section σ · BR (→øπ+) is equal to 11 ± 3 μb. © 1980, All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Λ and Λ production in K+p interactions at 32 GeV/c

A study of the inclusive and semi-inclusive Λ and Λ production in K+p interactions at 32 GeV/c is presented. The inclusive cross sections for Λ and Λ amount to 0.78 ± 0.05 and 0.42 ± 0.04 mb thus showing a remarkable growth between 16 and 32 GeV/c with a factor of 1.7 for Λ and 2.8 for Λ. Target and beam fragmentation processes are found to be dominant for Λ and Λ production respectively with the following lower limits for the corresponding cross sections: σ(p → K+v{inverted}) > 0.5 mb and σ(K+ → pv{inverted}) > 0.3 mb. Although the early scaling conditions are fulfilled for the Λ production in the target fragmentation region, and Λ production in the beam fragmentation region, scaling is not observed between 16 and 32 GeV/c in the x and pT2 Feynman variables. The Λ production is found to be very similar in the K+p inclusive reaction at 32 GeV/c and in the semi-inclusive reaction K-p→ ΛKKX at the same energy. The ΛΛ pair production cross section increases significantly in K+p interactions from 16 to 32 GeV/c where it reaches the value σΛΛ = 47 ± 11 μb. The cross sections for Λ or Λ produced in association with an identified proton are also given and discussed. © 1977.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

SEARCH FOR HEAVY NEUTRINO DECAYS IN THE BEBC BEAM DUMP EXPERIMENT

New limits on lepton mixing parameters are derived from a search for decays of heavy neutrinos in a proton beam dump experiment. The limits |Uøi|2, |Uei|2 < 10-6-10-7 are obtained for neutrino mass eigenstates vi of mass between 0.5 and 1.75 GeV, which can be produced through mixing in charmed D meson decays. This is the first such limit on |Uøi|2 for neutrino masses greater than 0.5 GeV. For the mass eigenstate v3 in particular, we obtain the limits |Uø3|2 < 10-7-10-8, |Ue3|2 < 10-9-10-10 for the mass range 150-190 MeV, assuming the v3 to be produced directly in charmed F meson decays. © 1985

SEARCH FOR TAU-NEUTRINO INTERACTIONS IN THE BEBC BEAM DUMP EXPERIMENT

A novel and efficient kinematic method is used to estimate the number of ντ charged current interactions with Eν > 20 GeV in the BEBC beam dump experiment. The result, -14±12 ντ events, is consistent with zero. The ratio of Ds to D meson production in 400 GeV proton interactions in copper is estimated to be below 0.65 at 90% c.l. The oscillation probability P(νe→ντ) averaged over the electron-(anti)neutrino spectrum is found to be below 18%. The hypothesis that νe and ντ are identical is excluded by about 6 standard deviations. A remarkable event is described: it contains a muon, a high pT photon and a high pT hadron. © 1987

BOUNDS ON LIGHT GLUINOS FROM THE BEBC BEAM DUMP EXPERIMENT

Observational upper limits on anomalous neutral-current events in a proton beam dump experiment are used to constrain the possible hadroproduction and decay of light gluinos. These results require ifmg̃ $ ̌4 GeV for ifmq̃ - minw. © 1985

AN INVESTIGATION OF THE EMC EFFECT USING ANTI-NEUTRINOS INTERACTIONS IN DEUTERIUM AND NEON

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 dσ/dx (ν Ne)/σ/dx (ν D2) at low x, independent of Q2 up to Q2 ∼ 14 GeV2. © 1984.058 auteursSCOPUS: ar.jinfo:eu-repo/semantics/publishe