HEPData Search

Interactions of 683-MeV/c negative pions with protons were investigated using the BNL 14-in. hydrogen bubble chamber in a 17-kG field. Two thousand elastic scatterings were analyzed, yielding a cross section of 18.9±1.0 mb. No evidence for powers of cosθ higher than the second was observed in the elastic angular distribution. The angular distribution obtained was dσdω=(0.384±0.026)+(1.70±0.06)cosθ+(3.36±0.11)cos2θ mb/sr. The single-pion production reactions π−+p→π−+π0+p and π−+p→π−+π++n were studied in detail. A total of 441 π0 productions and 833 π+ productions were analyzed giving cross sections of 3.99±0.50 and 7.50±0.80 mb, respectively. The differential distributions for these inelastic processes are presented and compared with the predictions of the model of Olsson and Yodh. The distribution of events on the Dalitz plots for π0 production is accounted for by the model. However, for the π+ reaction, the model (so far developed) does not describe adequately the distribution of events on the Dalitz plot. In particular, the model fails to account for the enhancement at high (π+π−) effective masses in ππ mass distribution. The center-of-mass angular distributions for π0 and π+ production reactions are presented and compared with the model.

3 data tables

Table 1

No description provided.

Table 2

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Table 3

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pi++p Interactions at 646 MeV

Oliver, John D. ; Nadelhaft, I. ; Yodh, G.B. ;

Phys.Rev. 147 (1966) 932-938, 1966.

Inspire Record 944954 DOI 10.17182/hepdata.26654

A 14-in. liquid-hydrogen-filled bubble chamber in a 17.5-kG magnetic field was exposed to a beam of negative pions produced by the Cosmotron at Brookhaven National Laboratory. About 26 000 pictures were taken and examined for the following final states: (1) elastic scattering (π−p); (2) π+ production (π−π+n); (3) π0 production (π−π0p); (4) neutrals. Values for the cross sections for these processes are σ(elastic)=17.56±0.43 mb, σ(π+)=7.14±0.23 mb, σ(π0)=4.65±0.17 mb. The elastic-scattering angular dependence in the c.m. system is fitted by a power-series expansion in cosθ and gives the following coefficients: a0=0.27±0.02, a1=1.48±0.11, a2=3.86±0.22, a3=−0.29±0.53, a4=−0.65±0.28, a5=1.69±0.52 (units: mb/sr). Cross sections for multiple-pion production were also measured: σ(π−π+π0n)=0.33±0.04 mb, σ(π−π+π−p)=0.08±0.02 mb. The total neutral cross section was σ(neutrals)=11.78±0.43 mb; the total charged events cross section was σ(charged)=29.76±0.69 mb; and the total cross section was σ(total)=41.54±0.82 mb. For single-pion production events, two-body mass distributions and angular distributions were compared with the predictions of the Olsson-Yodh isobar model.

1 data table

Table 1

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

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

Table 1

No description provided.

Differential Pion Charge-Exchange Scattering and $\eta$ Production: $\pi^-+p\to \pi^0 + n$ from 2.4 to 3.8 GeV/c, at 6 GeV/c and at 10 GeV/c, $\pi^-+p\to \eta^0 + n$ at 10 GeV/c

Wahlig, M.A. ; Mannelli, I. ;

Phys.Rev. 168 (1968) 1515-1526, 1968.

Inspire Record 1186784 DOI 10.17182/hepdata.749

Small-angle differential cross sections are presented here for π−+p→π0+n charge-exchange scattering between 2.4 and 3.8 GeV/c. The differential cross section near t=0 displays two minima and one maximum in this momentum interval, reflecting the presence of the N32*(2420), N32*(2850), and N12*(2650) resonances; at larger t values, the cross sections fall off exponentially as a function of t, just as has been previously observed for charge-exchange scattering above 6 GeV/c. The pion-charge-exchange data reported here at 6 and 10 GeV/c extend out to large angles, showing a maximum near t=0, followed by an exponential falloff as e10t, a minimum near −t=0.6 (GeV/c)2, and then a second maximum near −t=1.0 (GeV/c)2. The π−+p→η0+n differential cross section shows a maximum near t=0, followed by an exponential falloff as e4t, much less steep than the π0 slope. These data are compared to our previously published data and to those of the Saclay-Orsay group.

15 data tables

Table 1

No description provided.

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Pi-minus + p ---> k-neutral + lambda/sigma-neutral associated production in the forward direction at 6,8,10 and 11.2 gev/c

Bertolucci, E. ; Mannelli, I. ; Pierazzini, G. ; et al.

Lett.Nuovo Cim. 2S1 (1969) 149-155, 1969.

Inspire Record 58290 DOI 10.17182/hepdata.37419

None

2 data tables

Table 1

Only statistical errors are given.

Table 2

Only statistical errors are given.

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

Table 1

BY COMPARISON WITH THE KNOWN ETA PRODUCTION CROSS SECTION.

Differential cross-sections in pi- p ---> k0 lambda0 and pi- p ---> k0 sigma0 from 3 to 6 gev/c

Ward, C.E.W. ; Ambats, I. ; Lesnik, A. ; et al.

Phys.Rev.Lett. 31 (1973) 1149-1152, 1973.

Inspire Record 83757 DOI 10.17182/hepdata.21372

We have measured the differential cross sections for the associated-production reactions π−p→K0Λ0 and π−p→K0Σ0 at 3, 4, 5, and 6 GeV/c, with a total of over 40 000 events. We find that both reactions have exponential forward peaks for −t≲0.4 (GeV/c)2, with no indication of forward-direction flattening or turnover; the slopes of the forward peaks show little if any variation with momentum; and the two cross sections are equal within experimental error from −t=1.2 (GeV/c)2 out to at least −t=2.0 (GeV/c)2.

5 data tables

Table 1

INTERCEPT AND SLOPE FROM FIT TO D(SIG)/DT (PRESUMABLY FOR -TP < ABOUT 0.4 GEV**2).

Table 2

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Table 3

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Comparison of particle-antiparticle elastic scattering from 3 to 6 gev/c

Ambats, I. ; Ayres, D.S. ; Diebold, R. ; et al.

Phys.Rev.Lett. 29 (1972) 1415-1419, 1972.

Inspire Record 84577 DOI 10.17182/hepdata.21445

Differential cross sections for π±p, K±p, pp, and p¯p elastic scattering were measured at 3, 3.65, 5, and 6 GeVc for momentum transfers from 0.03 to 1.5 GeV2 using the Argonne effective mass spectrometer. Particular attention was paid to the relative particle-antiparticle normalization. The crossover points are consistent with no energy dependence, average values being 0.14 ± 0.03, 1.190 ± 0.005, and 0.160 ± 0.007 GeV2 for π's, K's, and protons, respectively.

1 data table

Table 1

No description provided.

Momentum dependence of the 180-degrees pi- p charge-exchange cross-section

Kistiakowsky, V. ; Feld, B.T. ; Triantis, F.A. ; et al.

Phys.Rev.D 6 (1972) 1882-1905, 1972.

Inspire Record 83145 DOI 10.17182/hepdata.3611

The π−+p→π0+n differential cross section at 180° has been measured for 52 values of π− momentum from 1.8 to 6.0 GeV/c using a constant-geometry detection system. The average statistical uncertainty is ∼5% and the systematic uncertainty is ∼10%. The details of the experiment and the data analysis are discussed. The data are compared with those of other experiments with which they are generally in agreement. One set of data disagrees with those presented here and a possible reason for this is discussed. A five-parameter fit of the predictions of a dual-resonance model to our data gave excellent agreement. The differential cross sections at 180° for π±p elastic scattering have been compiled and the moduli and relative phase of the T=12 and T=32 pion-nucleon s- and u-channel amplitudes (|A12|, |A32|, and cosδ) have a minimum at u=0.4 GeV/c and, in the s channel, a corresponding minimum at s=2.2 GeV/c.

53 data tables

Table 1

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HIGH-ENERGY pi- p ELASTIC SCATTERING FOR SMALL MOMENTUM TRANSFERS AND FORWARD DISPERSION CALCULATIONS

pi--p Interactions at 683 MeV/c

pi++p Interactions at 646 MeV

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

Differential Pion Charge-Exchange Scattering and $\eta$ Production: $\pi^-+p\to \pi^0 + n$ from 2.4 to 3.8 GeV/c, at 6 GeV/c and at 10 GeV/c, $\pi^-+p\to \eta^0 + n$ at 10 GeV/c

Pi-minus + p ---> k-neutral + lambda/sigma-neutral associated production in the forward direction at 6,8,10 and 11.2 gev/c

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

Differential cross-sections in pi- p ---> k0 lambda0 and pi- p ---> k0 sigma0 from 3 to 6 gev/c

Comparison of particle-antiparticle elastic scattering from 3 to 6 gev/c

Momentum dependence of the 180-degrees pi- p charge-exchange cross-section