Allison, John
Max results
Sort by Reverse order

Showing 10 of 3012 results

Date

Production of 4 pi+- and 6 pi+- by e+ e- Annihilation Between 2.4-GeV and 7.4-GeV

Jean-Marie, B. ; Abrams, G.S. ; Boyarski, A. ; et al.
SLAC-PUB-1711, 1976.
Inspire Record 108089 DOI 10.17182/hepdata.18658

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


rivet Analysis
Observation of a Resonance at 4.4-GeV and Additional Structure Near 4.1-GeV in e+ e- Annihilation

Siegrist, J. ; Abrams, G.S. ; Boyarski, A. ; et al.
Phys.Rev.Lett. 36 (1976) 700, 1976.
Inspire Record 108144 DOI 10.17182/hepdata.21093

We observe a resonancelike structure in the total cross section for hadron production by e+e− colliding beams at a mass of 4414 ± 7 MeV having a total width Γ=33±10 MeV. From the area under this resonance, we deduce the partial width to electron pairs to be Γee=440±140 eV. Further structure of comparable width is present near 4.1 GeV.

1 data table
Table 1

No description provided.


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.


Comparison of Neutral Particle Production in 100 GeV/c $\bar{p}p$ and pp Interactions.

Ward, D.R. ; Ansorge, R.E. ; Bust, C.P. ; et al.
Phys.Lett.B 62 (1976) 237-240, 1976.
Inspire Record 112616 DOI 10.17182/hepdata.5528

We derive cross-sections for the inclusive productiion in p̄p interactions at 100 GeV /c of π 0 , K S 0 and Λ 0 Λ 0 of 91.5±5.7 mb, 5.2±0.4 mb and 4.8±0.4 mb respectively, which are all higher than pp cross-sections at energy. We find indications that these differences can be attributed to “annihilation” processes.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

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 (?////).

More…

Neutron-Deuteron Elastic Scattering from 6-GeV/c to 12.5-GeV/c

Chanowski, John P. ; Gustafson, H. Richard ; Longo, Michael J. ; et al.
Phys.Lett.B 61 (1976) 93, 1976.
Inspire Record 2825 DOI 10.17182/hepdata.27665

The differential cross section for neutron-deuteron elastic scattering was measured for four-momentum transfers 0.3 < − t < 2.0 (GeV/c) 2 with incident neutron momenta between 6 and 12.5 GeV/c. The measurement was made with spark chambers at the Argonne ZGS. Results are compared with proton-deuteron elastic scattering at comparable energies as a test of isospin invariance in strong interactions and with the predictions of the Glauber multiple scattering theory. Very good agreement is found.

8 data tables
Table 1

UNPUBLISHED DATA.

Table 2

No description provided.

Table 3

UNPUBLISHED DATA.

More…

Evidence for anomalous lepton production in e+ e- annihilation.

Perl, Martin L. ; Abrams, G.S. ; Boyarski, A. ; et al.
Phys.Rev.Lett. 35 (1975) 1489-1492, 1975.
Inspire Record 100634 DOI 10.17182/hepdata.21164

We have found events of the form e++e−→e±+μ∓+missingenergy, in which no other charged particles or photons are detected. Most of these events are detected at or above a center-of-mass energy of 4 GeV. The missing-energy and missing-momentum spectra require that at least two additional particles be produced in each event. We have no conventional explanation for these events.

1 data table
Table 1

X IN RE INCLUDES TWO OR MORE UNDETECTED PARTICLES.


Azimuthal Asymmetry in Inclusive Hadron Production by e+ e- Annihilation

Schwitters, R. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 35 (1975) 1320, 1975.
Inspire Record 100683 DOI 10.17182/hepdata.21192

We have observed an azimuthal asymmetry in inclusive hadron production by e+e− annihilation at the center-of-mass energy s=7.4 GeV. The asymmetry is caused by the polarization of the circulating beams in the storage ring and allows separate determination of the transverse and longitudinal structure functions. We find that transverse production dominates for x>0.2 where x is the scaling variable 2ps.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


The Quantum Numbers and Decay Widths of the psi-prime (3684)

Luth, V. ; Boyarski, A. ; Lynch, H.L. ; et al.
Phys.Rev.Lett. 35 (1975) 1124-1126, 1975.
Inspire Record 100636 DOI 10.17182/hepdata.21229

Cross sections for e+e−→hadrons, e+e−, and μ+μ− near 3684 MeV are presented. The ψ(3684) resonance is established as having the assignment JPC=1−−. The mass is 3684 ± 5 MeV. The partial width for decay to electrons is Γe=2.1±0.3 keV and the total width is Γ=228±56 keV.

1 data table
Table 1

No description provided.


Charged-Particle Multiplicities in 100 GeV/c $\bar{p}p$ Interactions

Ansorge, R.E. ; Bust, C.P. ; Carter, J.R. ; et al.
Phys.Lett.B 59 (1975) 299-302, 1975.
Inspire Record 2603 DOI 10.17182/hepdata.27765

Results are presented on the topological cross sections obtained for antiproton-proton interactions from an exposure of the Fermilab 30-inch bubble chamber to a 100 GeV/ c negative beam enriched in p 's. The p p inelastic cross section is found to be σ inel = 34.6 ± 0.4 mb, and the average inelastic charged particle multiplicity to be 〈 n 〉 = 6.74 ± 0.05.

3 data tables
Table 1

ERRORS ARE STATISTICAL ONLY EXCEPT FOR 2-PRONG CROSS-SECTIONS.

Table 2

EXPONENTIAL FIT TO ELASTIC T DISTRIBUTION TO CORRECT FOR AN APPARENT LOSS OF EVENTS AT SMALL -T.

Table 3

MOMENTS OF 100 GEV/C AP P MULTIPLICITY DISTRIBUTION.