B. Tallini

Inclusive V0 production in pp interactions at 12 GeV/c

Results are presented on the inclusive reactions pp → K0X, pp → ΛX and pp → ΛX at an incident antiproton momentum of 12 GeV/c in BEBC. The cross sections are studied as functions of the Feynman scaling variable x, the rapidity, the transverse momentum of the V0 and the missing mass squared. The dependence of the Λ and Λ polarization on x are also studied. Comparisons with proton-proton data at 12 GeV/c are also made. Finally, events with two detected V0 are analyzed in order to study correlations arising from the production of two strange neutral particles.

Total cross sections νμ and ḡnμcharged-current interactions between 20 and 200 GeV

Abstract Exposures of the Ne/H 2 filled Big European Bubble Chamber (BEBC) to a dichromatic neutrino (antineutrino) beam produced by 400 GeV protons of the CERN SPS yielded ∼ 3100 events with a negative, and ∼ 1100 with a positive, muon. The neutrino flux is determined from the muon flux in the shielding. Assuming a linear energy dependence of the cross section, the values σ E between 20 and 200 GeV are found to be 0.657 ± 0.012 (stat.) ± 0.027 (syst.) and 0.309 ± 0.009 (stat.) ± 0.013 (syst.) cm 2 (GeV nucleon) −1 , for neutrinos and antineutrinos, respectively. The scaling variable q 2 E decreases significantly with increasing energy both for neutrinos and antineutrinos.

Spherocity and thrust distributions in high energy neutrino interactions

Abstract The study of the hadronic system of charged current neutrino interactions in terms of the variables spherocity ( S ) and thrust ( T ) is presented. It is found that 〈 S 〉 and 〈1− T 〉 for fixed hadronic energy are similar for neutrino interactions, e + e − annihilations and φ − Ne interactions.

Inclusive production of K*(890), Σ(1385) and S*(993) resonances in pp interactions at 12 GeV/c incident momentum

The reactions pp→K*(890)X, pp→Σ±(1385)X and pp→S*(993)X at 12 GeV/c incident momentum have been studied using 19 000 events with a visible V0 decay in BEBC. Inclusive production cross sections of these resonances as a function of transverse momentum and rapidity are presented. The contribution of annihilation to the production of the K*(890) is investigated from a comparison with the corresponding pp data.

Evidence for a narrow peak in Ksoπ±π+π- at 2.6 gev in 12 gev/ cpp interactions

Abstract We report the evidence for a narrow charged peak (5.5 s.d.), which we suggest calling the I, in the 6-prong-V 0 topology of p p interactions at 12 GeV/ c . The mass, widht and the product of cross section σ I times the branching ratio BR into the final state (K s o τ±τ + τ − are found to be: M I =2.60 ± 0.01 GeV / c 2 , Γ I ⩽ 0.018 GeV / c 2 , σ I ·BR≈20 μbarn

Inclusive V0 Production in anti-p p Interactions at 12-GeV/c

Results are presented on the inclusive reactions pp → K0X, pp → ΛX and pp → ΛX at an incident antiproton momentum of 12 GeV/c in BEBC. The cross sections are studied as functions of the Feynman scaling variable x, the rapidity, the transverse momentum of the V0 and the missing mass squared. The dependence of the Λ and Λ polarization on x are also studied. Comparisons with proton-proton data at 12 GeV/c are also made. Finally, events with two detected V0 are analyzed in order to study correlations arising from the production of two strange neutral particles.

A search for charmed particle production in pp interactions at 12 GeV/c

A search for charmed particles (D mesons, D* mesons and λc baryons) produced in pp interactions at 12 GeV/c incident beam momentum has been carried out using 16 500 events with a visible V0 decay in a 10 event/μb experiment in BEBC. No enhancements are observed in the invariant mass distributions of Ks0 + nπ (n = 1-5) and λ(λ) + nπ (n = 1-3) in the regions of the known charmed particle masses. The upper limits for the product of the inclusive production cross sections times decay branching ratios of D, D* and λc particles as well as the production of pairs of charmed mesons are calculated at 95% confidence level. The Ks0 yields per annihilation event in e+e- and pp interactions are compared at various energies.