pi--p Interactions at 604 MeV

Vittitoe, C.N. ; Riley, B.R. ; Fickinger, W.J. ; et al.
Phys.Rev. 135 (1964) B232-B240, 1964.
Inspire Record 46855 DOI 10.17182/hepdata.594

The interactions of 604 MeV π− mesons in a hydrogen bubble chamber have been systematically analyzed. In 33 000 pictures a total of 8052 usable events were found, corresponding to cross sections of 18.9±1.3 mb for σ(elastic), 4.98±0.54 mb for σ(π−pπ0), 7.87±0.91 mb for σ(π−nπ+), 14.0±1.0 mb for σ(neutrals), with σ(two−pionproduction)<0.2 mb, for a total cross section of 45.9±1.9 mb at this energy. The angular distribution for elastic scattering was fitted with a fifth-order polynomial in cosθ which gave a value of dσdΩ(0°) consistent with dispersion theory. The pion-pion effective-mass distributions for both single-pion-production channels showed pronounced peaking at high mass values, strongly inconsistent with simple isobar-production kinematics. Simple one-pion exchange does not appear to play a significant role.

2 data tables

No description provided.

No description provided.


Pion production in $\pi^-$ - $p$ interactions at energies 790, 830, and 870 {MeV}

Cason, N.M. ; Derado, I. ; Lamsa, J.W. ; et al.
Phys.Rev. 150 (1966) 1134-1140, 1966.
Inspire Record 50370 DOI 10.17182/hepdata.26587

Single-pion production has been studied in the reactions π−p→π−π+n and π−p→π−π0p at 790, 830, and 870 MeV. A total of 4193 events in these two channels, divided approximately equally between the three energies, have been identified. The most interesting feature of the data is the tendency for events to concentrate at high values of mππ and low values of four-momentum transfer. These effects are discussed in terms of conventional isobar models and a model involving two-pion exchange. Partial cross sections for the reactions studied are reported for each energy.

1 data table

No description provided.


Study of He-3 + He-3 Elastic Scattering and the Nucleus Be-6

Jenkin, J.G. ; Harrison, W.D. ; Brown, Ronald E. ;
Phys.Rev.C 1 (1970) 1622-1627, 1970.
Inspire Record 66302 DOI 10.17182/hepdata.26390

Differential cross sections for He3 + He3 elastic scattering have been measured at 18 angles from 12.5 to 45° (lab) at energies of 17.91, 20.00, 22.00, 24.00, 26.00, 28.00, and 30.00 MeV (lab). In addition, differential cross sections have been measured at intermediate energies from 19.00 to 32.00 MeV (lab) at angles of 20, 28, 36, and 45° (lab). The relative standard deviations of the data are generally less than 2%, and there is an additional standard deviation in the cross-section scale of 3%. The measurements are compared with theoretical calculations using the resonating-group method in the one-channel approximation. A broad resonance in the l=3 partial wave is predicted by the theory, and such a resonance has been observed in the present experiment. Differences between theory and experiment can be qualitatively understood as being caused principally by omission in the theory of reaction channels and noncentral forces. The effect of radial distortion in resonating-group calculations for the He3 + He3 system has also been investigated in an approximate manner. It is found that the effect can be quite significant for calculations of the energies of states in Be6 below the He3 + He3 threshold.

2 data tables

No description provided.

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A study of S wave pi pi scattering in the reaction pi+ n ---> pi0 pi0 p at 2.15 gev/c

Bensinger, J.R. ; Erwin, A.R. ; Thompson, M.A. ; et al.
Phys.Lett.B 36 (1971) 134-138, 1971.
Inspire Record 69178 DOI 10.17182/hepdata.28409

We have studied the 2 π 0 final states in the reaction π + d → π 0 π 0 p(p) at 2.15 GeV/ c in a 2 million picture exposure of the PPA rapid cycling deuterium bubble chamber. Two tantalum plates were added to the bubble chamber to convert γ rays which were kinematically constrained to a 2 π 0 hypothesis. The 2 π 0 mass spectrum is observed to saturate s-wave unitarity in the ππ mass region between 0.6 and 0.9 GeV/ c 2 , clearly favoring the ‘up-down’ or broad resonance solution for s-wave, I = 0, ππ scattering.

1 data table

No description provided.


X0 ---> 2gamma from pi- p ---> neutral meson + neutron at 3.8 gev/c

Apel, W.D. ; Auslaender, J. ; Mueller, H. ; et al.
Phys.Lett.B 40 (1972) 680-684, 1972.
Inspire Record 75664 DOI 10.17182/hepdata.28261

We report on a measurement for the branching-ratio X 0 → 2γ X 0 ar all. Our result is X 0 → 2γ X 0 → all = (2.9 ± 0.9)% .

1 data table

BY COMPARISON WITH THE KNOWN ETA PRODUCTION CROSS SECTION.


Interference between (p,f0 ...) and (rho0,b0,...) exchanges in pion diffraction dissociation at 16 gev/c

The Aachen-Berlin-Bonn-CERN-Heidelberg collaboration Beaupre, J.V. ; Deutschmann, M. ; Graessler, H. ; et al.
Phys.Lett.B 41 (1972) 393-396, 1972.
Inspire Record 75614 DOI 10.17182/hepdata.28235

It is found in the reactions π ± p →( π ± π + π − )p, believed to be dominated by diffraction dissociation, that the d σ d t′ distributions show a “cross-over” effect at t ′ ≈ 0.15, similar to the effect observed in elastic scattering. This gives evidence for the interference of ( ϱ 0 , B 0 ,…)-exchanges with ( P , f 0 , …) -exchanges in pion diffraction dissociation reactions. No such evidence is found for baryon dissociation, π ± p → π ± (p π + π − ), at the same energy.

8 data tables

No description provided.

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The reaction pi+ p ---> omega delta++(1236) at 11.7 gev/c

Evans, D. ; Maddock, R.O. ; Pinter, G.F. ; et al.
Nucl.Phys.B 51 (1973) 205-220, 1973.
Inspire Record 84297 DOI 10.17182/hepdata.32709

For the reaction π + p → ωΔ ++ data on the total cross section ( σ = 61 ± 12 μ b), differential cross sections, spin density matrix elements and statistical tensor elements are given. We observe natural and unnatural parity exchange contributions to the total cross section. We note that the value of ϱ 00 is not zero and in the helicity frame exhibits a dip at t ≈ −0.25 (GeV/ c ) 2 . A qualitative theoretical discussion of our results is presented.

9 data tables

CORRECTED FOR BACKGROUND, RESONANCE TAILS AND UNSEEN OMEGA DECAY MODES.

NORMALIZED TO THE TOTAL CROSS SECTION. SOME BACKGROUND IS PRESENT.

NORMALIZED TO THE TOTAL CROSS SECTION. SOME BACKGROUND IS PRESENT.

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Properties of the b-meson observed in 11 gev/c pi+- p interactions

Afzal, M. ; Evans, D. ; Neat, K.P. ; et al.
Nuovo Cim.A 15 (1973) 61-76, 1973.
Inspire Record 86986 DOI 10.17182/hepdata.37808

Production and decay properties of the B-meson are studied in the reactions π±p→B±p at 11 GeV/c. Values for mass, width, total and differential cross-sections and spin density matrix elements are given. The spin and parity, and the helicity states in the B→πω decay, are analysed.

3 data tables

BREIT-WIGNER FIT WITH 30 PCT BACKGROUND SUBTRACTED AND CORRECTED FOR UNSEEN OMEGA DECAYS.

FOR <OMEGA PION> EVENTS IN THE B REGION (1.16 TO 1.32 GEV) WITHOUT SUBTRACTING BACKGROUND.

ASSUMING B HAS SPIN-PARITY OF 1+.


Study of the reaction p d ---> he-3 x0

Brody, H. ; Groves, E. ; Van Berg, R. ; et al.
Phys.Rev.D 9 (1974) 1917-1932, 1974.
Inspire Record 92993 DOI 10.17182/hepdata.21985

The missing-mass technique has been used to study the spectra of neutral mesons produced by 2- and 3-Gev protons in the reaction p+d→He3+x0. Cross sections (dσdΩc.m.) of about 10−34 cm2/sr were observed for the π, η, and ω for 3-GeV protons. A peak with a much smaller cross section was observed at a mass of 956 MeV. We have tentatively identified this peak as the η′. Cross sections for the π and η were nearly a factor of 10 larger at 2 GeV than at 3 GeV. Deviations from simple phase space were observed near the two-pion threshold in both 2-GeV and 3-GeV data. Details of the experimental method and of the results are presented.

1 data table

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


Results on the production cross-sections pi- p ---> neutrals and pi- p ---> chi0(2gamma) n at 3.8, 6, 8 and 12 gev/c

Apel, W.D. ; Auslaender, J. ; Mueller, H. ; et al.
Phys.Lett.B 46 (1973) 459-464, 1973.
Inspire Record 95163 DOI 10.17182/hepdata.28058

The ratio between the cross sections for the reactions π − p→ χ ↳ 2γ 0 n and π − p → η →2 γ n has been measured to be (2.4 ± 0.9) × 10 −2 , (2.1 ± 0.6) × 10 −2 and (2.8 ± 1.3) × 10 −2 at 3.8,6,8 and 12 GeV/ c incident momentum respectively.

1 data table

ETAPRIME CROSS SECTIONS DEDUCED FROM THEIR RATIO TO ETA PRODUCTION, USING THE RESULTS OF O. GUISAN ET AL., PL 18, 200 (1965).