Messchendorp, J.G
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Test of Quantum Electrodynamics at {PETRA} Energies

The Aachen-DESY-Annecy(LAPP)-MIT-NIKHEF-Beijing collaboration Barber, D. ; Becker, U. ; Benda, H. ; et al.
Phys.Rev.Lett. 42 (1979) 1110, 1979.
Inspire Record 140093 DOI 10.17182/hepdata.20817

We report on the measurement of the reaction e+e−→e+e− with a large—solid-angle electromagnetic shower detector at center-of-mass energies s=13 and 17 GeV. Comparison of our results with predictions of quantum electrodynamics shows excellent agreement in both the angular distribution and energy dependence. Values of cutoff parameters are also given.

1 data table
Table 1

No description provided.


Production of $\psi$ and $\psi^\prime$ Mesons in $\pi^- N$ Scattering at 150-{GeV}/$c$

Abolins, M.A. ; Barate, R. ; Bareyre, P. ; et al.
Phys.Lett.B 82 (1979) 145, 1979.
Inspire Record 133175 DOI 10.17182/hepdata.27333

In a large-acceptance spectrometer, muon pairs and associated hadrons were observed with μμ masses up to 10 GeV/ c 2 and ΔM M = 0.015 resolution. We report here on the production of 4000 J/ ψ and 80 ψ ′ mesons.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Neutral Kaon Transmission Regeneration on Deuterons and Neutrons in Kaon Momentum Region of 10-GeV/c to 50-GeV/c

The Berlin-Budapest-Dubna-Prague-Serpukhov-Sofiya-Tbilisi collaboration Albrecht, K.F. ; Birulev, V.K. ; Vesztergombi, G. ; et al.
Sov.J.Nucl.Phys. 27 (1978) 199, 1978.
Inspire Record 122158 DOI 10.17182/hepdata.19037

None

4 data tables
Table 1

THE AVERAGE PHASE IS -130.9 +- 2.7 DEG (NO EXPLICIT MOMENTUM DEPENDENCE). USING ABS(ETA+-) = 2.3*10**-3.

Table 2

REGENERATION AMPLITUDE ASSUMING MOMENTUM INDEPENDENT CONSTANT PHASE.

Table 3

CROSS SECTION DIFFERENCES ASSUMING MOMENTUM INDEPENDENT CONSTANT PHASE.

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Hadronic Production of Massive Muon Pairs: Dependence on Incident Particle Type and on Target Nucleus.

Branson, J.G. ; Sanders, G.H. ; Smith, A.J.S. ; et al.
Phys.Rev.Lett. 38 (1977) 1334-1337, 1977.
Inspire Record 123331 DOI 10.17182/hepdata.21006

Data from a study of muon pairs produced in hadron-nucleus collisions are compared with the Drell-Yan model. Comparison of dimuon production by π+ and π− mesons on an isoscalar target shows evidence for a charge asymmetry characteristic of an isospin-nonconserving electromagnetic process. The average transverse momentum of the pairs increases smoothly with pair mass. Data taken on carbon and tin targets are used to extract the dependence on target atomic weight.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Production of the $J/\psi$ and $\psi^{\prime}$ (3.7) by 225 GeV/c $\pi^{\pm}$ and Proton Beams on C and SN Targets.

Branson, J.G. ; Sanders, G.H. ; Smith, A.J.S. ; et al.
Phys.Rev.Lett. 38 (1977) 1331-1334, 1977.
Inspire Record 123330 DOI 10.17182/hepdata.21022

We present results of a large-acceptance experiment in which muon pairs were observed in the mass range 0.6 to 6.0 GeV/c2. Emphasis is given to features of the production of Jψ and ψ′(3.7) particles. We find [Bσ]ψ′(3.7)[Bσ]Jψ to be 0.007±0.004 for p-C and 0.018±0.007 for π+-C interactions. Comparison with results from e+e− storage rings indicates that both the Jψ and the ψ′(3.7) are produced strongly rather than electromagnetically in our experiment.

1 data table
Table 1

No description provided.


Inclusive $\mu$ - Pair Production at 150 GeV by $\pi^+$ Mesons and Protons

Anderson, K.J. ; Henry, G.G. ; McDonald, K.T. ; et al.
Phys.Rev.Lett. 37 (1976) 799, 1976.
Inspire Record 3993 DOI 10.17182/hepdata.21035

We report the measurements of the inclusive μ-pair production by 150-GeV protons and π+ mesons on beryllium. Absolute cross sections as well as the Feynman-x and PT dependence are presented in the mass region between 0.211 and 3.5 GeV/c2. Upper limits are also given for the inclusive production of η and ρ′(1600) mesons.

7 data tables
Table 1

DATA OBTAINED FROM FIGURE BY A.A. LEBEDEV.

Table 2

DATA OBTAINED FROM FIGURE BY A.A. LEBEDEV.

Table 3

No description provided.

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Study of omega Production Near Threshold in the Reaction pi- p --> omega n

Keyne, J. ; Binnie, D.M. ; Carr, J. ; et al.
Phys.Rev.D 14 (1976) 28-41, 1976.
Inspire Record 115718 DOI 10.17182/hepdata.24698

We have investigated ω production in the reaction π−p→ωn very close to threshold. The dependence of the mass, width, branching ratio, and cross section upon the final-state c.m. momentum, P*, were studied. The mass and width were independent of P* with values of 782.4 ± 0.5 and 10.22 ± 0.43 MeV, respectively. The branching ratio Γ(ω→π0γ)Γ(ω→π+π−π0) was also constant, having a value of 0.084 ± 0.013. An upper limit of 0.18 was set on the branching ratio Γ(ω→π0π0γ)Γ(ω→π0γ). We observed a rapid fall in the cross section below P*=100 MeV/c. This could not be explained in terms of S-wave production alone, but could be fitted by a resonant P wave plus a noninterfering S wave.

1 data table
Table 1

CROSS SECTION DEPENDENCE ON FINAL STATE CENTRE OF MASS MOMENTUM. TABULATED VALUES TAKEN FROM TABLE 1 OF H. KARAMI ET AL., NP B154, 503 (1979).


The Polarized Beam Asymmetry in Photoproduction of eta Mesons from Protons at 2.5-GeV and 3.0-GeV

Bussey, P.J. ; Raine, C. ; Rutherglen, J.G. ; et al.
Phys.Lett.B 61 (1976) 479-482, 1976.
Inspire Record 108515 DOI 10.17182/hepdata.27687

Measurements of the polarised beam asymmetry parameter Σ for eta photoproduction from protons, have been carried out at incident energies of 2.5 GeV and 3.0 GeV, and for various t -values between −0.2 (GeV/c) 2 and −1.2 (GeV/c) 2 . The values of Σ are close to +1 for values of | t | less than 0.7 (GeV/c) 2 , showing that there can be little contribution from unnatural parity exchange in any Regge exchange model of the process, in disagreement with present theories. Differential cross sections for the process werre also measured, and are consistent with those from other experiments.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


A Measurement of the Beam Asymmetry Parameter Sigma for Neutral Pion Photoproduction in the Energy Range 1.2-GeV-2.8-GeV

Bussey, P.J. ; Raine, C. ; Rutherglen, J.G. ; et al.
Nucl.Phys.B 104 (1976) 253-276, 1976.
Inspire Record 100818 DOI 10.17182/hepdata.8492

An experiment has been completed at the Daresbury synchrotron to measure the asymmetry in the photoproduction cross section of neutral pions on hydrogen, for photons polarised normal to and in the production plane. The source of polarised photons was coherent bremsstrahlung of electrons traversing the lattice structure of diamond and the polarisation P of the γ beam was calculated from the measured intensity of the coherent spike. The asymmetry parameter Σ, defined as Σ = ( σ ⊥ − σ |)/( σ ⊥ + σ |) where σ ⊥( σ |) are the cross sections for photons polarised perpendicular (parallel) to the production plane, has been measured over a range of photon energies from 1.2 to 2.8 GeV and over a range of − t (the square of the four-momentum transfer) from 0.13 (GeV/ c ) 2 to 1.4 (GeV/ c ) 2 . A marked energy variation in the value of Σ is found over the energy region 1.6–1.8 GeV.

38 data tables
Table 1

Axis error includes +- 0.0/0.0 contribution (?////).

Table 2

Axis error includes +- 0.0/0.0 contribution (?////).

Table 3

Axis error includes +- 0.0/0.0 contribution (?////).

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Photoproduction of the psi Particles

Camerini, U. ; Learned, J.G. ; Prepost, R. ; et al.
Phys.Rev.Lett. 35 (1975) 483, 1975.
Inspire Record 100670 DOI 10.17182/hepdata.21149

The s and t dependence of incoherent ψ(3100) photoproduction from deuterium has been measured at the Stanford Linear Accelerator Center. ψ(3700) photoproduction and ψ(3100) photoproduction from hydrogen have also been measured.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.