Pi- p ELASTIC SCATTERING IN THE CMS ENERGY RANGE 1400-MeV TO 2000-MeV

Brody, A.D. ; Cashmore, R.J. ; Kernan, A. ; et al.
Phys.Rev.D 3 (1971) 2619, 1971.
Inspire Record 60976 DOI 10.17182/hepdata.4110

Total and differential cross sections for π−p elastic scattering are presented at 35 energies between 1400 and 2000 MeV.

1 data table match query

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Measurement of the reaction pi+ p ---> pi+ pi+ n near threshold

The OMICRON collaboration Kernel, G. ; Korbar, D. ; Krizan, P. ; et al.
Z.Phys.C 48 (1990) 201-208, 1990.
Inspire Record 297700 DOI 10.17182/hepdata.15134

The reaction π+p→π+π+n was studied in the vicinity of the reaction threshold at ten incident pion beam momenta from 297 MeV/c to 480 MeV/c. From data angular distributions, invariant mass spectra and integrated cross-sections were deduced. The chiral symmetry breaking parameter as determined by this reaction equals to ξ=1.56±0.26±0.39, where the first error is experimental, while the latter reflects the uncertainty in the ansatz used in the extrapolation to the reaction threshold. A comparison with the other reaction channels of the reaction πp→ππN indicates that a single parameter (ξ) is not sufficient to describe low energy ππ interactions.

1 data table match query

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Spin rotation parameters A and R for pi+ p and pi- p elastic scattering from 427-MeV/c to 657-MeV/c

Supek, I. ; Barlow, D.B. ; Briscoe, W.J. ; et al.
Phys.Rev.D 47 (1993) 1762-1775, 1993.
Inspire Record 362062 DOI 10.17182/hepdata.22623

The spin-rotation parameters A and R and the related spin-rotation angle β have been measured for π+p and π−p elastic scattering using protons polarized in the scattering plane. The pion-beam momenta are 427, 471, 547, 625, and 657 MeV/c and the angular range is −0.9≤cosΘc.m.≤0.3. The scattered pion and recoil proton were detected in coincidence, using a scintillator hodoscope for the pions, and the Large Acceptance Spectrometer combined with the JANUS polarimeter for the recoil protons. The results are compared with the four recent πN partial wave analyses (PWA's). Our data show that the major features of these PWA's are correct. The A and R measurements complete our program of pion-nucleon experiments, providing full data sets at three of the above beam momenta. Such sets can be used to test the constraints in the PWA's or to obtain a model-independent set of πN scattering amplitudes.

6 data tables match query

BETA is the spin-rotation angle.

BETA is the spin-rotation angle.

BETA is the spin-rotation angle.

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$\pi^- P$ Charge Exchange Analyzing Power From 547-{MeV}/c to 687-{MeV}/c

Wightman, J.A. ; Eichon, A.D. ; Kim, G.J. ; et al.
Phys.Rev.D 38 (1988) 3365-3374, 1988.
Inspire Record 270260 DOI 10.17182/hepdata.23237

The π−p charge-exchange analyzing power has been measured from 547 to 687 MeV/c in the center-of-mass angular range -0.9≤cosθ̃π≤0.9 using a transversely polarized target. The recoil neutron was detected in coincidence with a photon from π0 decay. The results are compared with the three recent partial-wave analyses (PWA’s); the VPI analysis is most consistent with our measured distributions except at 687 MeV/c where no PWA agrees with our data. The charge-exchange transversity cross sections are evaluated using the differential cross sections of Borcherding et al. These transversity cross sections are used in conjunction with earlier π±p data by our group to test the triangle inequalities which are a model-independent test of isospin invariance. Our data satisfy these inequalities everywhere; in contrast, Abaev et al. have reported a violation of more than 5 standard deviations at 685 MeV/c.

1 data table match query

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Recoil Proton Polarization in $\pi P$ Elastic Scattering at 547-{MeV}/c and 625-{MeV}/c

Seftor, C.J. ; Adrian, S.D. ; Briscoe, W.J. ; et al.
Phys.Rev.D 39 (1989) 2457-2463, 1989.
Inspire Record 282265 DOI 10.17182/hepdata.23234

The polarization of the recoil proton in π+p and π−p elastic scattering using a liquid-hydrogen target has been measured for backward angles at 547 and 625 MeV/c. The scattered pion and recoil proton were detected in coincidence using the large-acceptance spectrometer to detect and analyze the momentum of the pions and the JANUS polarimeter to identify and measure the polarization of the protons. Results from this experiment agree with other measurements of the recoil polarization, with analyzing-power data previously taken by this group, and with predictions of partial-wave analyses.

2 data tables match query

No description provided.

No description provided.


Polarized target asymmetry in pion proton bremsstrahlung at 298-MeV

Bosshard, A. ; Amsler, Claude ; Bistirlich, J.A. ; et al.
Phys.Rev.Lett. 64 (1990) 2619-2622, 1990.
Inspire Record 303404 DOI 10.17182/hepdata.22827

First data are presented for the polarized-target asymmetry in the reaction π+p→π+pγ at an incident pion energy of 298 MeV. The geometry was chosen to maximize the sensitivity to the radiation of the magnetic dipole moment μΔ of the Δ++(1232 MeV). A fit of the asymmetry in the cross section d5σ/dΩπ dΩγ dk as a function of the photon energy k to predictions from a recent isobar-model calculation with μΔ as the only free parameter yields μΔ=1.64(±0.19expΔ,±0.14 theor)μp. Though this value agrees with bag-model corrections to the SU(6) prediction μΔ=2μp, further clarifications on the model dependence of the result are needed, in particular since the isobar model fails to describe both the cross section and the asymmetry at the highest photon energies.

2 data tables match query

No description provided.

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Measurement of Pion Proton Bremsstrahlung for Pions at 299-{MeV}

Meyer, C.A. ; Amsler, Claude ; Bosshard, A. ; et al.
Phys.Rev.D 38 (1988) 754-767, 1988.
Inspire Record 268867 DOI 10.17182/hepdata.23271

We have measured the fivefold differential cross section d5σ/dΩπdΩγdEγ for the process π+p→π+pγ with incident pions of energy 299 MeV. The angular regions for the outgoing pions (55°≤θlabπ≤95°), and photons (θlabγ=241°±10°) in coplanar geometry are selected to maximize the sensitivity to the radiation from the magnetic dipole moment of the Δ++(1232) resonance. At low photon energies, the data agree with the soft-photon approximation to pion-proton bremsstrahlung. At forward pion angles the data agree with older data and with the latest theoretical calculations for 2.3μp≤μΔ≤3.3μp. However at more backward pion angles where no data existed, the predictions fail.

2 data tables match query

No description provided.

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Analyzing Power for $\pi^- P$ Charge Exchange and a Test of Isospin Invariance Up to $\eta$ Threshold

Wightman, J.A. ; Eichon, A.D. ; Kim, G.J. ; et al.
Phys.Rev.D 36 (1987) 3529-3532, 1987.
Inspire Record 255689 DOI 10.17182/hepdata.23322

The analyzing power for π−p→π0n has been measured at five incident momenta from 547 to 687 MeV/c using a transversely polarized target. Data were obtained with scintillation counters at 10 angles simultaneously covering the range −0.9≤cosθc.m.π≤0.9. Our results and those of Kim et al. are used for a model-independent test of isospin invariance which is based on the triangle inequalities applied to the transversity-up as well as the transversity-down cross sections. No evidence is found of isospin violation.

1 data table match query

No description provided.


Cross-section Measurement of $\pi^- p \to \pi^- \pi^+ n$ Reaction Near Threshold

The OMICRON collaboration Kernel, G. ; Korbar, D. ; Krizan, P. ; et al.
Phys.Lett.B 216 (1989) 244-248, 1989.
Inspire Record 264989 DOI 10.17182/hepdata.29858

Result of cross section measurements for the reaction π − p → π − π + n are presented. They cover a range of incident pion momenta between 295 and 450 MeV/ c . It is the first time that the cross section has been measured so close to threshold. The experiment was performed with Omicron, a large-solid-angle spectrometer, which enables a measurement of the full set of kinematic variables. In the region of overlap there is a good agreement with other experiments. The extracted value for the chiral-symmetry-breaking parameter ξ is seen to be largely extrapolition dependent but the measured value of -0.5±0.8 leaves Weinberg's prediction of ξ =0 the only remaining choice.

1 data table match query

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Measurement of Differential Cross-Sections for Radiative Pion-Proton Capture in the Second Resonance Region

Weiss, A.J. ; Blasberg, D.J. ; Comiso, J.C. ; et al.
Nucl.Phys.B 101 (1975) 1-18, 1975.
Inspire Record 2234 DOI 10.17182/hepdata.36075

Differential cross-section measurements for π − p → γ n, consisting of three angular distributions at 618, 676 and 718 MeV/ c , and the energy dependence at θ γ = 90° for seven incident pion momenta between 502 and 888 MeV/ c , are presented. Our data qualitatively support recent multipole analyses. Agreement with the Scheffler et al. results for the inverse reaction, γ n → π − p, using a ( π − -recoil p) coincidence technique is good excluding a large violation of time reversal invariance. The agreement with γ n → π − p data obtained using the R ( π − / π + ) ratio technique or a deuterium bubble chamber is only qualitative.

1 data table match query

Axis error includes +- 6.6/6.6 contribution.