Date

Study of Hypercharge Exchange Reactions of the Type 0- 1/2+ $\to$ 2+ 1/2+ at 4-{GeV}/$c$

The CERN-College de France-Madrid-Stockholm collaboration Aguilar-Benitez, M. ; Albajar, M.C. ; Ferrando, A. ; et al.
Z.Phys.C 8 (1981) 313, 1981.
Inspire Record 156685 DOI 10.17182/hepdata.13530

Results are presented for the quasi two-body hypercharge exchange reactions of the type 0−1/2+→2+1/2+:$$\begin{gathered}

12 data tables

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Measurement of the $\pi^-$ Form-factor

Dally, E.B. ; Drickey, Darrell James ; Hauptman, J.M. ; et al.
Phys.Rev.D 24 (1981) 1718-1735, 1981.
Inspire Record 172687 DOI 10.17182/hepdata.26467

An experiment to measure the electromagnetic form factor of the negative π meson has been carried out at Fermilab by elastically scattering 100-GeV/c pions from the atomic electrons in a liquid-hydrogen target. We find that the elastic differential scattering cross section is characterized by a root-mean-square pion charge radius of 0.56±0.04 fm. This paper described our experimental design, measurement resolutions, event triggering logic, event reconstruction, experimental corrections, and form-factor results.

3 data tables

No description provided.

Axis error includes +- 0.54/0.54 contribution (EVENT-FINDING CORRECTIONS).

No description provided.


Lepton Pair Production and Search for a New Heavy Lepton in $e^+ e^-$ Annihilation

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 99 (1981) 489-494, 1981.
Inspire Record 164302 DOI 10.17182/hepdata.27110

We have measured the reaction ee → μμ and ee → ττ at center of mass energies from 9.4 to 31.6 GeV. The production cross sections are in agreement with the predictions of quantum electrodynamics, resulting in cutoff parameter limits of 70–100 GeV at 95% c.l. The branching ratio for τ → μν ν has been determined as [1.78 ± 2.0 (statist.) ± 1.8(syst.)]% The existence of a new sequential heavy lepton with a mass <14.5 GeV is excluded at 95% c.l.

2 data tables

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$\Delta (\Sigma^-$l) and $\Delta$ (Sigma-t) Between 200-{MeV} and 520-{MeV}

Axen, D. ; Shypit, R. ; Comyn, M. ; et al.
J.Phys.G 7 (1981) L225-L230, 1981.
Inspire Record 171520 DOI 10.17182/hepdata.38530

New pp measurements of Delta sigma L and Delta sigma T between 200 and 520 MeV disagree with earlier Argonne data, and resolve discrepancies with inelastic data, phase-shift analysis and forward dispersion relations.

2 data tables

TOTAL CROSS SECTION DIFFERENCE FOR PURE TRANSVERSE SPIN STATES (ANTIPARALLEL MINUS PARALLEL).

TOTAL CROSS SECTION DIFFERENCE FOR PURE LONGITUDINAL SPIN STATES (ANTIPARALLEL MINUS PARALLEL).


DELTA (1236) PRODUCTION IN ANTI-NEUTRINO n ---> mu+ n pi- REACTION AT HIGH-ENERGIES

Efremenko, V.I. ; Fedotov, A.V. ; Gorichev, P.A. ; et al.
ITEP-83-1981, 1981.
Inspire Record 167553 DOI 10.17182/hepdata.40191

None

5 data tables

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BACKWARD PRODUCTION OF THE B (1235) MESON IN 11.46-GEV/C PI+ P INTERACTIONS

Wong, M.K. ; Key, A.W. ; Schwarzschild, B.M. ; et al.
Phys.Rev.Lett. 46 (1981) 974, 1981.
Inspire Record 169864 DOI 10.17182/hepdata.20643

Evidence for the backward production of the B(1235) meson in the final state π+p→pfπ+ω at 11.46 GeV/c with σ(|u′|<1.5 GeV2)=1.28±0.26 μb is presented. When nucleon exchange is assumed to dominate, estimates for the SU(3) mixing parameter FD as well as the B coupling to the nucleon-antinucleon are given. Some indication of a narrow enhancement at M(π+ω)≃1.03 GeV/c2 is seen, but confirmation of this as a resonant state is not yet possible.

2 data tables

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A Measurement of the Cross-Section for Four Pion Production in gamma gamma Collisions at SPEAR

Burke, D.L. ; Abrams, G.S. ; Alam, M.S. ; et al.
Phys.Lett.B 103 (1981) 153-156, 1981.
Inspire Record 165016 DOI 10.17182/hepdata.31168

We present a measurement of the cross section for the reaction e + e − → e + e − π + π − π + π − at SPEAR. This channel is found to be large and dominated by the process γγ → ϱ 0 ϱ 0 → π + π − π + π − . The cross section, which is small just above the four-pion threshold, exhibits a large enhancement near the ϱ 0 ϱ 0 threshold.

1 data table

Axis error includes +- 0.0/0.0 contribution (THE QUOTED ERRORS INCLUDE VARIOUS SYSTEMATIC ERRORS ADDED QUADRATICALLY).


Inclusive $K^0$ Production in $e^+ e^-$ Annihilation for 9.3-{GeV} $<\sqrt{s}<$ 31.6-{GeV}

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 104 (1981) 79-83, 1981.
Inspire Record 165122 DOI 10.17182/hepdata.6716

Results on inclusive K s 0 production in e + e − annihilation at mean center-of-mass energies of 9.4, 12.0 and 30 GeV are presented. The ratio R (K 0 ) = 2 σ (K s 0 )/ σ μμ rises from 3.10 ± 0.75 at √ s = 9.4 GeV to 5.6 ± 1.2 at √ s = 30 GeV, corresponding to an approximately constant K 0 /charged-particle ratio of 0.12 ± 0.02. A similar ratio for K 0 / charged particle is observed for direct hadronic decays of the ϒ.

7 data tables

SYSTEMATIC ERROR INCLUDED.

NUMBER OF K0 PER HADRONIC EVENT. AUTHORS ALSO USE MULTIPLICITY TO ESTIMATE NUMBER OF K0 PER CHARGED PARTICLE.

INCLUDING EARLIER DATA.

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A Study of the Reaction $\pi^- p \to \phi \phi n$ at 16-{GeV}/$c$

The Aachen-Bari-Bonn-CERN-Glasgow-Liverpool-Milan collaboration Armstrong, T.A. ; Baccari, B. ; Booth, P.S.L. ; et al.
Nucl.Phys.B 196 (1982) 176-188, 1982.
Inspire Record 165251 DOI 10.17182/hepdata.34217

The reaction π − p → φφ n has been isolated at 16 GeV/ c and its cross section determined to be 40 ± 10 nb. The φφ mass spectrum shows a threshold enhancement between 2.1 and 2.5 GeV. A successful description of the angular content of the φφ system requires two interferingss J P = 2 + states.

2 data tables

No description provided.

SLOPE OF DIFFERENTIAL TP(P=3,P=2) DISTRIBUTION.


Observation of $\mu^+ e^+$ Events in Anti-neutrino - Nucleon Interactions

The Fermilab-Serpukhov-Moscow-Michigan collaboration Ammosov, V.V. ; Denisov, A.G. ; Ermolov, P.F. ; et al.
Phys.Lett.B 106 (1981) 151-154, 1981.
Inspire Record 166059 DOI 10.17182/hepdata.41257

The first observation of μ + e + events produced in antineutrino interactions using the Fermilab 15 ft bubble chamber is reported. The relative yield of μ + e + events is (4.8 −3.2 +5.3 ) × 10 −4 of all charged-current events with antineutrino energy greater than 10 GeV. The observed V 0 rate is 1.0 −1.0 +1.2 per μ + e + event. Possible sources of these events are discussed.

1 data table

No description provided.