Ayre, C.A.
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Interaction of Positive Pions with Hydrogen at 600 MeV

Newcomb, Peter C.A. ;
Phys.Rev. 132 (1963) 1283-1292, 1963.
Inspire Record 47245 DOI 10.17182/hepdata.26734

The Berkeley 15-in. hydrogen bubble chamber was used to investigate π+−p interactions at 600 MeV. There were 1738 good events, of which 71.9±0.8% were elastic. Partial waves up to at least D52 are required to fit the elastic angular distribution. The inelastic events were almost entirely single-pion production. The ratio (p+0)(n++) was found to be 5.5±0.8 which agrees well with 4.9 predicted by the (32, 32) pion-nucleon isobar model of Olsson and Yodh. It is also consistent with 6.5 predicted by Sternheimer and Lindenbaum. The pion momentum spectra and the π−π Q-value distributions also support the Olsson and Yodh model. Thus the (32, 32) pion-nucleon isobar is apparently the principal mechanism for single-pion production at 600 MeV. Angular distributions for the single-pion-production data are presented.

1 data table match query
Table 1

No description provided.


Direct Photon Production at High $p_T$ in $\pi^-$Be and pBe Collisions at 500 GeV/c

Alverson, G. ; Baker, W.F. ; Ballocchi, G. ; et al.
Phys.Rev.Lett. 68 (1992) 2584-2587, 1992.
Inspire Record 318739 DOI 10.17182/hepdata.19865

We report new measurements of inclusive direct photon production at high transverse momenta (pT) for π− and p interactions on Be at 500 GeV/c. The yields as a function of pT and rapidity (y) are in good agreement with expectations from next-to-leading-log QCD calculations employing recently extracted quark and gluon structure functions.

1 data table match query
Table 1

No description provided.


Inclusive Production of Direct Photons in 200-{GeV}/$c$ Collisions

McLaughlin, M. ; Biel, J. ; Bromberg, C. ; et al.
Phys.Rev.Lett. 51 (1983) 971, 1983.
Inspire Record 191763 DOI 10.17182/hepdata.20473

The authors have measured the inclusive production of direct photons in the transverse momentum (pT) range 2.1-5.0 GeV/c in 200-GeV/c collisions of protons and π+ mesons on a carbon target. A significant yield of direct photons was observed for pT>2.5 GeV/c. The invariant cross section for direct-photon production, when compared with measurements from the CERN intersecting storage rings, can be expressed in terms of pT and xT=2pTs as (42±14)(1−xT)8.1±1.0pT−6.6±0.3 μb/GeV2 for the c.m. energy range from s=19.4 to 63 GeV, and for the xT range from 0.2 to 0.5.

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


Nuclear Enhancement of pi0 and eta mesons Produced at Large Transverse Momenta

Povlis, J. ; Biel, J. ; Bromberg, C. ; et al.
Phys.Rev.Lett. 51 (1983) 967, 1983.
Inspire Record 191764 DOI 10.17182/hepdata.20477

The authors have measured the large-pT inclusive cross sections for π0 and η production near 90° in the center-of-mass system in 200-GeV/c π+ and proton collisions with beryllium, carbon, and aluminum targets. The cross section for both π0 and η mesons rises with increasing nucleon number (A) of the target nucleus as Aα, with α>1. The ratio of the π0 yield in pA collisions to that in π+A collisions decreases with increasing pT.

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


Rho+- Photoproduction at 9.6-GeV

Abramson, J. ; Andrews, D.E. ; Busnello, R. ; et al.
Phys.Rev.Lett. 36 (1976) 1432, 1976.
Inspire Record 108497 DOI 10.17182/hepdata.21105

ρ± photoproduction from hydrogen and deuterium at 9.6 GeV is studied. The reactions γp→ρ+n and γp→ρ−Δ++(1236) have cross sections much larger than expected from pion exchange alone. t distributions do not show the sharp forward peak characteristic of one-pion exchange contributions. Density matrices indicate an isotropic decay distribution. The ratio of ρ+ to ρ− production on deuterium differs from unity and by the amount expected from interference between ρ and A2 exchanges. We conclude that π exchange is unimportant for ρ± photoproduction, and infer that ρ exchange dominates.

6 data tables match query
Table 1

No description provided.

Table 2

No description provided.

Table 3

DENSITY MATRICES IN HELICITY FRAME - UNPUBLISHED.

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Inelastic Photoproduction of omega and rho+- Mesons

Nelson, C.A., Jr. ; May, E.N. ; Abramson, J. ; et al.
Phys.Rev.D 17 (1978) 647, 1978.
Inspire Record 4373 DOI 10.17182/hepdata.24401

We report measurements of inelastic photoproduction of ω and ρ± mesons from hydrogen and deuterium at incident photon energies in the range 7.5-10.5 GeV. For ωΔ and ρ−Δ++ production, differential cross sections dσdt′ and spin density matrices are presented. For higher missing masses the cross sections dσdMX2 and invariant structure functions F(x) are also given. The data are compared to a one-pion-exchange model. We conclude that pion exchange is dominant for inelastic ω photoproduction, but unimportant for ρ±.

4 data tables match query
Table 1

CROSS SECTION PER NUCLEON FOR COMBINED HYDROGEN AND DEUTERIUM DATA ALLOWING FOR A GLAUBER CORRECTION FACTOR OF 0.88 FOR THE DEUTERIUM CROSS SECTIONS.

Table 2

HYDROGEN AND DEUTERIUM DATA COMBINED BY AVERAGING.

Table 3

OBTAINED BY EXTRAPOLATING A FIT TO D(SIG)/DT OVER -T = 0 TO 0.52 GEV**2.

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Partial Wave Analysis of Coherent 3 $\pi$ Production on Nuclei at 200-{GeV}

Zielinski, M. ; Berg, D. ; Chandlee, C. ; et al.
Phys.Rev.D 30 (1984) 1855, 1984.
Inspire Record 15136 DOI 10.17182/hepdata.23674

We have carried out a partial-wave analysis (PWA) of three-pion systems produced in the coherent dissociation of π+ mesons on nuclear targets. The data have been analyzed for copper and lead targets at an incident π+ energy of 202.5 GeV. This PWA provides further evidence for resonant contributions to JP=1+ and 0− waves at 3π masses below 1.5 GeV, which can be plausibly identified with A1 and π′ mesons. The contribution from electromagnetic production of the A2 has also been extracted, and an estimate for Coulomb production and radiative width of the A1 has been obtained.

1 data table match query
Table 1

No description provided.


PRODUCTION OF LOW MASS K+ omega SYSTEMS ON NUCLEI

Zielinski, M. ; Berg, D. ; Chandlee, C. ; et al.
Phys.Rev.D 30 (1984) 1107, 1984.
Inspire Record 15686 DOI 10.17182/hepdata.23675

We have measured the coherent nuclear production of low-mass K+ω systems in K+A collisions at 202.5 GeV. Results for carbon, copper, and lead targets are similar to those found for π+π+π− production in π+A reactions at the same energy.

1 data table match query
Table 1

M(K+ OMEGA) < 1.5 GEV.


Production of $\pi^0$ Mesons at high $p_T$ in $\pi^-$Be and pBe Collisions at 500 GeV/c

Alverson, G. ; Baker, W.F. ; Ballocchi, G. ; et al.
Phys.Rev.D 45 (1992) R3899-R3902, 1992.
Inspire Record 318740 DOI 10.17182/hepdata.22751

We present new measurements of π0 production at high transverse momenta (pT) for π− and p interactions on Be and Cu targets at 500 GeV/c. The observed dependence of the yields as a function of pT and rapidity (y) is compared with expectations from leading-log QCD over a kinematic range in which the inclusive cross sections fall by more than 4 order of magnitude.

2 data tables match query
Table 1

No description provided.

Table 2

A dependence parameterized as A**POWER for both Pi- and P interactions.


An Improved Upper Limit for Photoproduction of psi (3105) Near Threshold

Andrews, D.E. ; Harvey, John R. ; Lobkowicz, F. ; et al.
Phys.Rev.Lett. 34 (1975) 1134-1136, 1975.
Inspire Record 98255 DOI 10.17182/hepdata.21225

An improved upper limit for ψ photoproduction near threshold is presented.

1 data table match query
Table 1

The branching ratio for J/PSI --> E+ E- is taken as 0.06.