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Neutrino Counting With the Cello Detector and Search for Supersymmetric Particles

The CELLO collaboration Behrend, H.J. ; Criegee, L. ; Dainton, J.B. ; et al.

Phys.Lett.B 215 (1988) 186-194, 1988.

Inspire Record 261670 DOI 10.17182/hepdata.22766

A search for single photons, produced in e + e − collisions together with particles interacting only weakly with matter, has been performed using the CELLO detector at the PETRA storage ring. We report on results from data taken at 35 GeV < √ s <46.57 GeV. An upper limit of 8.7 (90% CL) on the number of light neutrino species is set. Combining our result with published results from other e + e − experiments the number of light neutrinos is limited to N v < 4.6 at 90% CL. We also set lower limits on the masses of supersymmetric particles.

1 data table

Table 1

TWO RUN AT DIFFERENT ENERGIES COMBINED, 1.26 EVENTS WAS FOUND.

The Acceleration of Polarized Protons to 22-{GeV}/$c$ and the Measurement of Spin Spin Effects in $p$ (Polarized) + $p$ (Polarized) $\to p + p$

Khiari, F.Z. ; Cameron, P.R. ; Court, G.R. ; et al.

Phys.Rev.D 39 (1989) 45, 1989.

Inspire Record 262472 DOI 10.17182/hepdata.23245

Accelerating polarized protons to 22 GeV/c at the Brookhaven Alternating Gradient Synchro- tron required both extensive hardware modifications and a difficult commissioning process. We had to overcome 45 strong depolarizing resonances to maintain polarization up to 22 GeV/c in this strong-focusing synchrotron. At 18.5 GeV/c we measured the analyzing power A and the spin-spin correlation parameter Ann in large- P⊥2 proton-proton elastic scattering, using the polarized proton beam and a polarized proton target. We also obtained a high-precision measurement of A at P⊥2=0.3 (GeV/c)2 at 13.3 GeV/c. At 18.5 GeV/c we found that Ann=(-2±16)% at P⊥2=4.7 (GeV/c)2, where it was about 60% near 12 GeV at the Argonne Zero Gradient Synchrotron. This sharp change suggests that spin-spin forces may have a strong and unexpected energy dependence at high P⊥2.

3 data tables

Table 1

No description provided.

Table 2

2.2 GeV point taken from Brown et al., PR D31(85) 3017.

Table 3

No description provided.

rivet Analysis
Investigation of the Total Charm Pair Cross-section in Nonresonant $e^+ e^-$ Annihilations at $\sqrt{s}=10$.5-{GeV}

The CLEO collaboration Bowcock, T.J.V. ; Kinoshita, K. ; Pipkin, F.M. ; et al.

Phys.Rev.D 38 (1988) 2679, 1988.

Inspire Record 23509 DOI 10.17182/hepdata.9269

We report results from two new methods for measuring the total production of charmed particles in nonresonant e+e− annihilations at √s =10.5 GeV. The rate for detection of events containing two reconstructed charmed mesons relative to that for events containing one is used to extract information about total charm production independent of decay branching fractions. The value of ΔRcc¯, the total charm-pair cross section normalized to the pointlike μ-pair cross section, is found to be 1.13−0.13+0.17±0.09, under an assumption of limited particle correlations. In an independent analysis the inclusive cross section for e+e−→qq¯→e±X is measured to be 0.293±0.017±0.017 nb. Using measured relative production rates and semileptonic branching fractions of D0 and D+ mesons and estimates of these quantities for Ds and Λc, this is found to correspond to ΔRcc¯=2.07±0.12±0.26. These two measurements are discussed in the context of measurements made by reconstruction of exclusive hadronic decay modes and of theoretical expectations.

3 data tables

Table 1

Charm quarks production cross section (C=CQCQBQR) evaluated from tagged events.

Table 2

Results using method 1).

Table 3

Results using method 2).

Study of Multi - Hadron Events With Isolated Leptons in $e^+ e^-$ Annihilation at $50\le \sqrt{s} \le 55$-{GeV}

The VENUS collaboration Abe, K. ; Amako, K. ; Arai, Y. ; et al.

Phys.Lett.B 207 (1988) 355-360, 1988.

Inspire Record 23570 DOI 10.17182/hepdata.29946

We have studied inclusive lepton production in e + e − annihilations into multihadrons in the energy range between √ s =50 and 55 GeV using the VENUS detector at TRISTAN, KEK. Though MARK-J and JADE groups at PETRA found an excess of isolated muon events at √ s ⩾46.3 GeV, we have not observed such an anomaly in muon nor in electron production. The observed rates of isolated leptons are consistent with the production and decay of five known quarks.

4 data tables

Table 1

Observed rates for whole event sample.

Table 2

No description provided.

Table 3

No description provided.

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rivet Analysis
Measurement of the Reaction $e^+ e^- \to \eta \pi^+ \pi^-$ in the Center-of-mass Energy Interval 1350-{MeV} to 2400-{MeV}

The DM2 collaboration Antonelli, A. ; Baldini, R. ; Calcaterra, A. ; et al.

Phys.Lett.B 212 (1988) 133-138, 1988.

Inspire Record 264144 DOI 10.17182/hepdata.29912

The e + e − → ηπ + π − reaction has been measured in the center of mass energy interval 1350–2400 MeV by the magnetic detector DM2 at the Orsay storage ring DCI. Under the hypothesis of only one large resonance the cross section is not fit in a satisfactory way. The branching ratio τ − → η − π 0 ν τ =(0.13 ± 0.02)% is deduced via CVC from the above measurement.

1 data table

Table 1

No description provided.

rivet Analysis
Observation of the Charmed Baryon $\Sigma(c$) in $e^+ e^-$ Annihilations

The ARGUS collaboration Albrecht, H. ; Bockmann, P. ; Glaser, R. ; et al.

Phys.Lett.B 211 (1988) 489-492, 1988.

Inspire Record 261672 DOI 10.17182/hepdata.29913

Using the ARGUS detector at the DORIS II storage ring, we have observed the charmed baryons Σ c ++ and Σ c 0 , through their decays to Λ c + π ± . We have measured the mean Σ c −Λ c + mass difference as 167.6±0.3±1.6 MeV/ c 2 . The isospin mass splitting between the Σ c ++ and the Σ c 0 was found to be 1.2±0.7±0.3 MeV/ c 2 . The rate of Λ c + production from Σ c decays was found to be (36±12±11)% of the total rate of Λ c + production. The Σ c χ p spectrum was observed to be similar to that of the Λ c + , with a Peterson function parameter ϵ of 0.29±0.06.

1 data table

Table 1

DATA FROM UPSI(4S) WAS EXCLUDED.

Shadowing in deep inelastic muon scattering from nuclear targets

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.

Phys.Lett.B 211 (1988) 493-499, 1988.

Inspire Record 262246 DOI 10.17182/hepdata.29908

Results are presented on the ratio of the inelastic muon-nucleus cross section per nucleon for carbon and calcium relative to that for deuterium. The measurements were made in the kinematic range of low x (0.003–0.1) and low Q 2 (0.3–3.2 GeV 2 ) at an incident muon energy of 280 GeV. The calcium to deuterium ratio shows a significant x dependence which is interpreted as a shadowing effect. No strong Q 2 dependence is observed. This suggests that the effect is due at least partially to parton interactions within the nucleus.

4 data tables

Table 1

VALUES OF Q**2 AT EACH POINT ARE:- 0.52,0.60,0.61,0.61,0.63,0.68,0.90.

Table 2

VALUES OF Q**2 AT EACH POINT ARE:- 1.09,1.25,1.54,1.74,1.76,1.68,1.71, 2.29.

Table 3

VALUES OF X AT EACH POINT ARE:- 0.009,0.011,0.010,0.010,0.010,0.011, 0.013,0.015.

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First Observation of Dielectron Production at the Bevalac

The DLS collaboration Roche, G. ; Claesson, G. ; Hendrie, D. ; et al.

Phys.Rev.Lett. 61 (1988) 1069-1072, 1988.

Inspire Record 268588 DOI 10.17182/hepdata.38105

We have begun a program to measure dielectron production in p-nucleus and nucleus-nucleus collisions at the LBL Bevalac. Results are presented for the reaction p+Be at 4.9 GeV. For the first time, direct dilepton production is observed below 10 GeV incident energy. The cross sections are discussed and compared to previous data at higher energies. The observation of a structure at a mass of about 275 MeV suggests that pion annihilation may be the dominant production mechanism in this mass range.

2 data tables

Table 1

A IS TARGET ATOMIC MASS NUMBER.

Table 2

A IS TARGET ATOMIC MASS NUMBER.