Neutral strange particle exclusive production in charged current high-energy antineutrino interactions

The cross section of the quasi-elastic reactions \(\bar v_\mu p \to \mu ^ + \Lambda (\Sigma ^0 )\) in the energy range 5–100 GeV is determined from Fermilab 15′ bubble chamber antineutrino data. TheQ ² analysis of quasi-elastic Λ events yieldsM _A=1.0±0.3 GeV/c² for the axial mass value. With zero µΛ K ⁰ events observed, the 90% confidence level upper limit \(\sigma (\bar v_\mu p \to \mu ^ + \Lambda {\rm K}^0 )< 2.0 \cdot 10^{ - 40} cm^2 \) is obtained. At the same time, we found that the cross section of reaction \(\bar v_\mu p \to \mu ^ + \Lambda {\rm K}^0 + m\pi ^0 \) is equal to \(\left( {3.9\begin{array}{*{20}c} { + 1.6} \\ { - 1.3} \\ \end{array} } \right) \cdot 10^{ - 40} cm^2 \) .     

Diffractive production of charmed strange mesons by neutrinos and antineutrinos

The diffractive production of charmed strangeD _s ^* and possiblyD _s mesons by neutrinos and antineutrinos on nucleons in hydrogen, deuterium and neon targets is observed. The slope parameter of thet distribution is 3.3±0.8 (GeV)^?2. The production rate per charged current neutrino interaction with an isoscalar target times the D _s ⁺ →φτ⁺ branching fraction is (1.03±0.27)×10^?4.     

First observation of the doubly charmed baryon Xi(+)(cc)

We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1+/-0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is 3519+/-1 MeV/c(2). The Gaussian mass width of this state is 3 MeV/c(2), consistent with resolution; its lifetime is less than 33 fs at 90% confidence.     

Observation ofD S ** (2536) meson production by neutrinos in BEBC

Zeitschrift für Physik C Particles and Fields - Neutrino interactions in BEBC produce theD ** (2536) charmed strange meson. The mass of this state is 2534.2±1.2 MeV. The production rate...     

Formation of a narrow baryon resonance with positive strangeness in K + collisions with Xe nuclei

The data on the charge-exchange reaction K ⁺Xe → K ⁰ pXe′, obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK ⁰ resonance with mass near 1538 MeV is confirmed. The statistical significance of the signal reaches some 8 (6) standard deviations when estimated as $ {S \mathord{\left/ {\vphantom {S {\sqrt B \left( {{S \mathord{\left/ {\vphantom {S {\sqrt {B + S} }}} \right. \kern-0em} {\sqrt {B + S} }}} \right)}}} \right. \kern-0em} {\sqrt B \left( {{S \mathord{\left/ {\vphantom {S {\sqrt {B + S} }}} \right. \kern-0em} {\sqrt {B + S} }}} \right)}} $ . The mass and intrinsic width of the Θ⁺ baryon are measured as m = 1538 ± 2 MeV and Γ = 0.39 ± 0.10 MeV.     

Study ofD *+ and search forD **0 production by neutrinos in BEBC

Data from BEBC experiments are combined to provide large statistics for neutrino interactions. ChargedD ^* mesons are produced in (1.22±0.25)% of neutrino and (1.01±0.31)% of antineutrino charged current interactions. The mean fraction of the hadronic laboratory energy taken by theD ^*+ in these events is 0.59±0.03±0.08. Less than 18% of all chargedD ^* mesons from (anti)neutrino interactions are found to be daughters ofD ^**0 (at the 90% confidence level).     

νμp and νμn charged-current interactions unfolded from high energy νμ interactions in neon

We have developed a method to separate $\text{ν}$n and $\text{ν}$p interactions from antineutrino-neon interactions by using the final state electric charge. We present the distributions of the scaling variables x and y for $\text{ν}$n and $\text{ν}$p interactions separately , along with the $\text{ν}$n and $\text{ν}$p cross section ratios as a function of x and y. We obtain a total $\text{ν}$n to $\text{ν}$p cross section ratio of 0.45± 0.08. Our results are consistent with the predictions of the simple quark parton model.