This paper reports on measurements of the total cross section for the inclusive reaction vμ+N, as a function of incident energy. Neutrinos and antineutrinos with energy in the range 3
Data from 100 to 300 GeV are combined with previous measurements and errors have statistical and systematics combined.
Cross section using direct normalization.
Cross section using direct normalization.
A sample of 8000 interactions of 250 GeV/c π+ andK+ mesons on Al and Au nuclei, is used to search for intermittency effects by calculating the normalized factorial moments of order two to four. No significant effect is observed in the higher moments. Two-body rapidity correlations and Bose-Einstein correlations in these interactions are presented.
No description provided.
As part of a programme to study the spin structure of the p p→ n n channel, we have measured the analysing power A 0 n and the differential cross section at an incident antiproton beam momentum of 704 MeV/ c . The analysing power exhibits a remarkable angular dependence, which is poorly reproduced by the existing potential models.
No description provided.
No description provided.
In a photoproduction experiment using a mean photon energy of 100 GeV we have observed 29±8 Λ c ( Λ c ) charmed-baryon and antibaryon decays in the pK − π + ( p K + π − ) final state. Quasi two-body final states do not contribite significantly to this channel. The mass of the Λ c was measured to be 2281.7±2.7±2.6 MeV/ c 2 and its lifetime 0.18±0.03±0.03 ps. The ratio of Λ c D production, measured in this experiment, is significantly greater than that predicted by photon-gluon fusion and using a Lund model to describe the hadronization. This excess cannot be completely accounted for in this model, even using a Λ c branching fraction in pK π as high as 5%.
Result extrapolated to all lambda/c energies has large model dependent uncertainties.
The Crystal Ball detector has been used at the DORIS II storage ring at DESY to study the reactionγγ→π0π0π0 in theπ0π0π0 invariant mass range from 850 MeV/c2 to 2600 MeV/c2. An enhancement around 1750 MeV/c2 is attributed to theπ2(1670) resonance. The observedπ0π0 invariant mass distribution and theπ0 angular distributions are consistent with those expected for the decay chainπ2→π0f2(1270)→π0π0π0. From our measurements we find the following resonance parameters: two photon partial width\(\Gamma _{\pi _2 }^{\gamma \gamma }= (1.41 \pm 0.23 \pm 0.28)keV\), massM(π2)=(1742±31±49)MeV/c2. and total width\(\Gamma _{\pi _2 }^{tot}= (236 \pm 49 \pm 36)MeV\).
Data read from graph.
Cross section times branching ratio to 3pi0 assuming the decay chain pi2 --> pi0f2 --> 3pi0.
None
No description provided.
No description provided.
We have measured the rate of D ∗± meson production inside the jets produced in p p collisions at √ s = 630 GeV. For jets in the transverse energy range 15< E T <60 GeV we find a production rate of 0.10±0.04±0.03 D ∗± per jet, which is in good agreement with perturbative QCD calculations. In addition, we find that the D ∗± fragmentation distribution is strongly peaked towards low z consistent with gluon splitting as the dominant production mechanism.
No description provided.
Using the ARGUS detector at the e + e − storage ring DORIS II at DESY, we have observed production of the charmed-strange baryon Ξ c + and its neutral isospin partner, the Ξ c 0 . The Ξ c + was reconstructed in the final state Ξ − π + π + , while the Ξ c 0 was seen in decay to Ξ − π + and Ξ − π + π + π − . The average Ξ c fragmentation spectrum has been determined, as well as the production cross section times branching ratio for each decay mode. The charged and neutral masses were measured to be 2465.1 ± 3.6 ± 1.9 MeV/ c 2 and 2472.1 ± 2.7 ± 1.6 MeV/ c 2 respectively, corresponding to a mass-splitting, M ( Ξ c + ) − M ( Ξ c 0 ), of −7.0±4.5±2.2 MeV/ c 2 .
Cross sections times branching ratios for $\Xi_c^0$ and $\Xi_c^+$ production at $E_{\mathrm{cms}} = 10.5$ GeV and $x_p > 0.5$.
Cross sections times branching ratios for $\Xi_c^0$ and $\Xi_c^+$ production at $E_{\mathrm{cms}} = 10.5$ GeV and all $x_p$.
Data requested from authors.
We have measured the cross section for production of ψ and ψ′ in p¯ and π− interactions with Be, Cu, and W targets in experiment E537 at Fermilab. The measurements were performed at 125 GeV/c using a forward dimuon spectrometer in a closed geometry configuration. The gluon structure functions of the p¯ and π− have been extracted from the measured dσdxF spectra of the produced ψ's. From the p¯W data we obtain, for p¯, xG(x)=(2.15±0.7)[1−x](6.83±0.5)[1+(5.85±0.95)x]. In the π− case, we obtain, from the W and the Be data separately, xG(x)=(1.49±0.03)[1−x](1.98±0.06) (for π−W), xG(x)=(1.10±0.10)[1−x](1.20±0.20) (for π−Be).
No description provided.
No description provided.
No description provided.
We present the charged-particle multiplicity distributions for e+e− annihilation at center-of-mass energies from 50 to 61.4 GeV. The results are based on a data sample corresponding to a total integrated luminosity of 30 pb−1 obtained with the AMY detector at the KEK storage ring TRISTAN. The charged-particle multiplicity distributions deviate significantly from the modified Poisson and pair Poisson distributions, but follow Koba-Nielsen-Olesen scaling and are well reproduced by the LUND parton-shower model.
Fully corrected charged particle multiplicity distributions. Errors for n=2 and 4 are systematic only since these were derived using the LUND 6.3 Monte Carlo normalized to the observations at higher n values.
No description provided.
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