HEPData Search

Showing 9 of 99 results

Observation of a Peak at 1.28-{GeV} in the $\eta \pi \pi$ System in the Reaction $\gamma p \to \eta \pi^+ \pi^- p$

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.

Nucl.Phys.B 242 (1984) 269-281, 1984.

Inspire Record 194474 DOI 10.17182/hepdata.33873

A peak is reported in the ηπ + π − system, produced in the reaction γ p→ ηπ + π − p, at a mass of 1.28 ± 0.01 GeV with a width of 0.08 ± 0.02 GeV. Possible spin-parity assignments for the peak are shown to be J π = 1 − , J π = 1 + or J π = 2 + and interpretations of these assignments are discussed.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Observation of Semileptonic Decays of Charmed Baryons

Vella, E. ; Trilling, G. ; Abrams, G.S. ; et al.

Phys.Rev.Lett. 48 (1982) 1515, 1982.

Inspire Record 176986 DOI 10.17182/hepdata.19674

Direct electrons are observed in baryon events produced in e+e− annihilation at center-of-mass energies above the ΛcΛ¯c threshold. These events are attributed to charmed-baryon pair production and subsequent Λc semileptonic decay. Various semileptonic branching ratios of the Λc are determined, including B(Λc→e+X)=(4.5±1.7)%.

2 data tables

Table 1

ELECTRON-BARYON RATIO ABOVE AND BELOW LAMBDA/C THRESHOLD.

Table 2

No description provided.

RESONANCE PRODUCTION BY TWO PHOTON INTERACTIONS AT SPEAR

Jenni, P. ; Burke, D.L. ; Telnov, Valery I. ; et al.

Phys.Rev.D 27 (1983) 1031, 1983.

Inspire Record 173430 DOI 10.17182/hepdata.23843

Two-photon interactions have been studied with the SLAC-LBL Mark II magnetic detector at SPEAR. The cross section for η′ production by the reaction e+e−→e+e−η′ has been measured at beam energies from 2.0 to 3.7 GeV. The radiative width Γγγ(η′) has been determined to be 5.8±1.1 keV (±20% systematic uncertainty). Upper limits on the radiative widths of the f(1270), A2(1310), and f′(1515) tensor mesons have been determined. A search has been made for production of the E(1420) by γγ collisions, but no signal is observed.

2 data tables

Table 1

No description provided.

Table 2

NO SIGNAL ABOVE BACKGROUND SEEN. UPPER LIMITS AT 95 PCT CL GIVEN.

Pion Pair Production in Photon - Photon Collisions at {SPEAR}

Roussarie, A. ; Burke, D.L. ; Abrams, G.S. ; et al.

Phys.Lett.B 105 (1981) 304-308, 1981.

Inspire Record 166578 DOI 10.17182/hepdata.31056

We report a measurement of the cross section for the process γγ → π + π − at invariant masses 500 MeV/ c 2 < m ππ <2000 MeV/ c 2 . A value for the radiative width of the f(1270) tensor meson Γ f→ γγ = 3.6 ± 0.3 ± 0.5 KeV (helicity λ = 2) has been obtained from a fit to the observed ππ mass spectrum.

1 data table

Table 1

DATA REQUESTED FROM AUTHORS.

Photoproduction of Charmed F Mesons at $\gamma$ Energies of 20-{GeV} to 70-{GeV}

The Bonn-CERN-Ecole Poly-Glasgow-Lancaster-Manchester-Orsay-Paris-Rutherford-Sheffield collaboration Aston, D. ; Atkinson, M. ; Bailey, R. ; et al.

Phys.Lett.B 100 (1981) 91-94, 1981.

Inspire Record 155586 DOI 10.17182/hepdata.31208

Evidence is presented for inclusive photoproduction of F ± mesons in three decay modes, ηπ ± , ηπ ± π + π − and ηπ ± π + π + π − π − . The average mass of the F ± is found to be 2.020±0.010 GeV.

1 data table

Table 1

No description provided.

CROSS-SECTIONS FOR PI- + P ---> N + (K) PI0 (K = 1 TO 5) AND PI- + P ---> N + ETA0 (ETA0 ---> 2 GAMMA) FOR INCIDENT PION MOMENTA BETWEEN 1.3-GEV/C AND 3.8-GEV/C

Crouch, H.R. ; Hargraves, R. ; Lanou, R.E. ; et al.

Phys.Rev.D 21 (1980) 3023-3058, 1980.

Inspire Record 158169 DOI 10.17182/hepdata.4334

This paper presents the results of a study of the dominant neutral final states from π−p interactions. The data were obtained in an experiment performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron, using a set of steel-plate optical spark chambers surrounding a liquid-hydrogen target. We present differential and total cross sections for the reactions (1) π−p→n+π0 and (2) π−p→n+η0(η0→2γ) and total cross sections for the reactions (3) π−p→n+kπ0 (k=2, 3, 4, and 5) and (4) π−p→all neutrals for eighteen values of beam momentum in the interval 1.3 to 4.0 GeV/c. The angular distributions for (1) and (2) have been analyzed in terms of expansions in Legendre polynomials, the coefficients for which are also given.

41 data tables

Table 1

No description provided.

Table 2

SIG = 4*PI*LEG(L=0).

Table 3

FORWARD DIFFERENTIAL CROSS SECTION CALCULATED FROM LEGENDRE POLYNOMIAL COEFFICIENTS AND ERROR MATRICES.

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Measurement of $\bar{p} p \to \pi^0 \pi^0$, $\pi^0$ Eta0 in the $T$ and U Meson Region

Dulude, R.S. ; Lanou, R.E. ; Massimo, J.T. ; et al.

Phys.Lett.B 79 (1978) 329-334, 1978.

Inspire Record 130456 DOI 10.17182/hepdata.27379

We present measurements from a counter-optical spark chamber experiment of the differential cross sections for p̄p → π 0 π 0 , π 0 η 0 at 25 momenta in the range 1.1 − 2.0 GeV/ c (c.m. energy 2.12 to 2.43 GeV). Approximately 750 000 pictures were taken in the experiment.

4 data tables

Table 1

THE ANGULAR DISTRIBUTIONS IN THE PUBLISHED FIGURES ARE NOT TABULATED HERE SINCE THEY ARE ONLY RECONSTRUCTED FROM THE LEGENDRE EXPANSION COEFFICIENTS WHICH WERE MEASURED DIRECTLY FROM THE DATA.

Table 2

No description provided.

Table 3

LEGENDRE COEFFICIENTS NORMALIZED SO THAT LEG(L=0) = SIG/(2*PI) (IDENTICAL PARTICLES IN FINAL STATE). THESE ARE PLOTTED IN FIG. 1 OF THE FOLLOWING PAPER.

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ELECTRON - PROTON SCATTERING AT LOW MOMENTUM ENERGIES

Lehmann, P. ; Taylor, R.E. ; Wilson, Richard ;

Phys.Rev. 126 (1962) 1183, 1962.

Inspire Record 16521 DOI 10.17182/hepdata.26811

We have measured the electron-proton scattering cross section at 248.9 Mev, 104.81°; 209.6 Mev, 149.75°; and 139.3 Mev, 104.19°. We find the following values: F1=0.767±0.025, F2=0.707±0.028, and F1F2=1.085±0.025 at −q2=2.98 f−2. F=0.902±0.011 at −q2=1.05 f−2. The last result agrees with previous measurements. The others are new contributions.

2 data tables

Table 1

No description provided.

Table 2

No description provided.