Exclusive measurements of pi+- p --> pi+ pi+- n near threshold.

The CHAOS collaboration Kermani, M. ; Amaudruz, P.A. ; Bonutti, F. ; et al.
Phys.Rev.C 58 (1998) 3419-3430, 1998.
Inspire Record 483005 DOI 10.17182/hepdata.25726

The pion induced pion production reactions π±p→π+π±n were studied at projectile incident energies of 223, 243, 264, 284, and 305 MeV, using a cryogenic liquid hydrogen target. The Canadian High Acceptance Orbit Spectrometer was used to detect the two outgoing pions in coincidence. The experimental results are presented in the form of single differential cross sections. Total cross sections obtained by integrating the differential quantities are also reported. In addition, the invariant mass distributions from the (π+π−) channel were fitted to determine the parameters for an extended model based on that of Oset and Vicente-Vacas. We find the model parameters obtained from fitting the (π+π−) data do not describe the invariant mass distributions in the (π+π+) channel.

2 data tables match query

Total cross sections were obtained by integrating the differential cross section over all three variables: M(pi,pi)**2, t, Cos(Theta(pi)).

Total cross sections were obtained by integrating the differential cross section over all three variables: M(pi,pi)**2, t, Cos(Theta(pi)).


Measurement of pi- p --> pi0 pi0 n from threshold to p(pi-) 750-MeV/c.

The Crystal Ball collaboration Prakhov, S. ; Nefkens, B.M.K. ; Allgower, C.E. ; et al.
Phys.Rev.C 69 (2004) 045202, 2004.
Inspire Record 647544 DOI 10.17182/hepdata.25355

Reaction π−p→π0π0n has been measured with high statistics in the beam momentum range 270–750MeV∕c. The data were obtained using the Crystal Ball multiphoton spectrometer, which has 93% of 4π solid angle coverage. The dynamics of the π−p→π0π0n reaction and the dependence on the beam energy are displayed in total cross sections, Dalitz plots, invariant-mass spectra, and production angular distributions. Special attention is paid to the evaluation of the acceptance that is needed for the precision determination of the total cross section σt(π−p→π0π0n). The energy dependence of σt(π−p→π0π0n) shows a shoulder at the Roper resonance [i.e., the N(1440)12+], and there is also a maximum near the N(1520)32−. It illustrates the importance of these two resonances to the π0π0 production process. The Dalitz plots are highly nonuniform; they indicate that the π0π0n final state is dominantly produced via the π0Δ0(1232) intermediate state. The invariant-mass spectra differ much from the phase-space distributions. The production angular distributions are also different from the isotropic distribution, and their structure depends on the beam energy. For beam momenta above 550MeV∕c, the density distribution in the Dalitz plots strongly depends on the angle of the outgoing dipion system (or equivalently on the neutron angle). The role of the f0(600) meson (also known as the σ) in π0π0n production remains controversial.

2 data tables match query

Measured total cross section. Statistical errors only.

Differential angular distributions of the 2PI0 system for the LH2 data at beam momenta 355 to 472 MeV/c. Statistical errors only.


Measurement of $\pi^- p \to \pi^- p \pi^0$ Reaction Near Threshold and Breaking of Chiral Symmetry

The OMICRON collaboration Kernel, G. ; Korbar, D. ; Krizan, P. ; et al.
Phys.Lett.B 225 (1989) 198-202, 1989.
Inspire Record 278272 DOI 10.17182/hepdata.29804

A full-kinematics measurement of the π − p→ π − p π 0 reaction in the incident π − momentum region from 295 to 450 MeV/ c is presented. The measurement was performed with the OMICRON spectrometer at the CERN synchrocyclotron.

1 data table match query

Integrated cross section.


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

No description provided.


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

No description provided.


Elastic Scattering of 300-MeV Negative Pions by Hydrogen

Vasilevskii, I.M. ; Vishnyakov, V.V. ;
Sov.Phys.JETP 11 (1960) 323-326, 1960.
Inspire Record 1407579 DOI 10.17182/hepdata.70213

The elastic scattering of 300-Mev negative pions from hydrogen was studied with the aid of a hodoscopic system with pulse-fed counters. Equation (1) gives the angular distribution for the elastic scattering under the hypothesis that the fundamental contribution to the scattering comes from the S and P waves.

1 data table match query

No description provided.


Positive pion-proton scattering at energies 176, 200, 240, 270, 307 and 310 Mev

Mukhin, A.I. ; Ozerov, E.B. ; Mitin, N.A. ; et al.
204-224, 1956.
Inspire Record 1186667 DOI 10.17182/hepdata.70406

None

1 data table match query

No description provided.


Recoil proton polarization in elastic $\pi^−$ p scattering at 300 MeV and the phase shift analysis of pion-nucleon scattering

Vasilevsky, I.M. ; Vishnyakov, V.V. ; Ivanchenko, I.M. ; et al.
Phys.Lett. 23 (1966) 174-176, 1966.
Inspire Record 1408342 DOI 10.17182/hepdata.70432

The results of a measurement of recoil proton polarization for π−p → π−p at 300 MeV are given, and a phase shift analysis is made with the help of other data.

1 data table match query

No description provided.


Elastic Scattering of 240-330 MeV π- Mesons by Hydrogen

Zinov, V.G. ; Korenchenko, S.M. ;
Sov.Phys.JETP 11 (1960) 794, 1960.
Inspire Record 1407580 DOI 10.17182/hepdata.70214

Results of measurements of differential cross sections for the elastic scattering of 11'- mesons of energies 240, 270, 307 and 333 Mev by hydrogen are given.

2 data tables match query

No description provided.

No description provided.


Charge-Exchange Scattering of 240-300 MeV π- Mesons on Hydrogen

Zinov, V.G. ; Korenchenko, S.M. ;
Sov.Phys.JETP 11 (1960) 1010-1015, 1960.
Inspire Record 1407581 DOI 10.17182/hepdata.70216

The results are given of the measurement of the differential cross sections of charge-exchange scattering of 240, 270, 307, and 333-Mev 1r- mesons on hydrogen.

2 data tables match query

No description provided.

No description provided.


A Search For the $\rho^0$ Meson and a Check of the Dispersion Relations in π-N Scattering

Zinov, V.G. ; Konin, A.D. ; Korenchenko, S.M. ; et al.
Sov.Phys.JETP 11 (1960) 1233-1238, 1960.
Inspire Record 1407582 DOI 10.17182/hepdata.70224

The total 1r- -p interaction cross sections (of) were measured with an accuracy of 1.5-2% for about 50 pion energies between 140 and 360 Mev. The pion energy was known to within ± 1%. No anomalies in the energy dependence of Of were found which could indicate the existence of a p0meson with a mass in the range of 270 to 410 Mev/c2• The data are inconsistent with the energy value E2 = 650 Mev for the second maximum of Of found by Frisch et al. 7 but agree with the conclusion drawn by Brisson et al. 8 that it should be located at a lower energy ( E2 :::::: 610 Mev). The data are in agreement with the dispersion relations for 1r- -p scattering. It is thus demonstrated that the PuppiStanghellini problem as such no longer exists and that it arose only as a result of an inaccurate knowledge of the total 1r--p interaction cross section.

1 data table match query

No description provided.


Left-right Asymmetry in Inverse $\pi^-$ Photoproduction From a Transversely Polarized Proton Target

Kim, G.J. ; Adrian, S.D. ; Arends, J. ; et al.
Phys.Rev.Lett. 56 (1986) 1779-1782, 1986.
Inspire Record 232117 DOI 10.17182/hepdata.20259

Accurate measurements of the left-right asymmetry in π−p→γn at pπ=427−625 MeV/c with a transversely polarized target are reported. Results are compared with the predictions from the Arai and Fujii single-pion photoproduction partial-wave analysis and with data on the inverse process measured with a deuterium target. The agreement is poor, casting doubt on the correctness of the value for the radiative-decay amplitude of the neutral Roper resonance now in use.

3 data tables match query

No description provided.

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.

No description provided.


Measurement of the left-right asymmetry in pi- p ---> gamma n from 301-GeV/c to 625-MeV/c at backward angles

Kim, G.J. ; Engelage, J. ; Nefkens, B.M.K. ; et al.
Phys.Rev.D 43 (1991) 687-695, 1991.
Inspire Record 316108 DOI 10.17182/hepdata.22828

The left-right asymmetry of π−p→γn has been measured using a transversely polarized target at seven pion momenta from 301 to 625 MeV/c, mostly at photon angles of 90° and 110° c.m. The final-state γ and neutron were detected in coincidence. Neutrons were recorded in two arrays of plastic scintillators and the γ's in two matching sets of lead-glass counters. The results are compared with the predictions from the two most recent single-pion photoproduction partial-wave analyses. The agreement with the analysis of Arai and Fujii is poor, casting some doubt on the correctness of their values for the radiative decay amplitude of the neutral Roper resonance which are used widely. The agreement is much better with the results of the VPI analysis. Also, a comparison is made with the recoil-proton polarization data from the inverse reaction measured at 90° with a deuterium target. It reveals substantial discrepancies, indicating the shortcomings of the deuterium experiments for neutron target experiments. Our data are also compared with several bag-model calculations.

3 data tables match query

No description provided.

No description provided.

No description provided.


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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Measurement of the Recoil Proton Polarization in Elastic $\pi^-p$ Scattering at $T_\pi=410$ and 492 MeV

Bareyre, P. ; Bricman, C. ; Longo, M.J. ; et al.
Phys.Rev.Lett. 14 (1965) 878-880, 1965.
Inspire Record 945162 DOI 10.17182/hepdata.21824

None

1 data table match query

No description provided.


Measurement of the Recoil Proton Polarization in Elastic pi+p Scattering at Tpi=410and492 MeV

Bareyre, P. ; Bricman, C. ; Longo, M.J. ; et al.
Phys.Rev.Lett. 14 (1965) 198-201, 1965.
Inspire Record 944925 DOI 10.17182/hepdata.21847

None

1 data table match query

No description provided.


The total cross-sections for pion-proton scattering between 70 mev and 290 mev

Carter, A.A. ; Williams, J.R. ; Bugg, D.V. ; et al.
Nucl.Phys.B 26 (1971) 445-460, 1971.
Inspire Record 68771 DOI 10.17182/hepdata.21874

Measurements have been made of the π ∓ proton total cross sections over the laboratory kinetic energy range 70 to 290 MeV. The absolute accuracy of the data is generally 0.5 %, but decreases to 1 % for some points where applied corrections are large or where low particle fluxes limit the statistical accuracy.

2 data tables match query

No description provided.

No description provided.


The pi- p ---> pi0 n charge-exchange cross-sections between 90 mev and 290 mev

Bugg, D.V. ; Bussey, P.J. ; Dance, D.R. ; et al.
Nucl.Phys.B 26 (1971) 588-596, 1971.
Inspire Record 68770 DOI 10.17182/hepdata.21877

Measurements have been made of the total charge-exchange cross section π − p to π 0 n over the laboratory kinetic energy range 90 to 290 MeV. The data have an absolute accuracy of typically 1%, and have here been used to determine the pion-nucleon P 13 phase shift.

2 data tables match query

No description provided.

No description provided.


Differential cross-sections of pi- p ---> gamma n for 317, 452, and 491 mev/c incident pion momentum

Berardo, P.A. ; Haddock, R.P. ; Nefkens, B.M.K. ; et al.
Phys.Rev.D 9 (1974) 621-643, 1974.
Inspire Record 93116 DOI 10.17182/hepdata.21950

The differential cross sections of π−p→γn at center-of-mass energy Ẽ=1363, 1337, and 1245 MeV are presented. The angular distributions are compared with recent γn→π−p experiments. Though the cross sections for π−p→γn are somewhat lower than those for the inverse reaction, when all uncertainties are considered, we find that our data are in acceptable agreement at all three energies with the inverse reaction determined from π−π+ ratio measurements, in support of time-reversal invariance. The agreement with bubble-chamber measurements at Ẽ=1363 and 1337 MeV is less satisfactory. The isotensor dip test applied to our data is inconclusive. Our measurements are compared with many multipole analyses, disagreeing with most, in particular with pure fixed- t dispersion relation calculations. We find no evidence, in the sense suggested by Donnachie, for the classification of the P11(1470) resonance in an SU(3) antidecuplet. The data are consistent with a small radiative decay of the P11(1470) resonance, as predicted by quark models.

4 data tables match query

Axis error includes +- 4.5/4.5 contribution.

Axis error includes +- 4.2/4.2 contribution.

Axis error includes +- 4.5/4.5 contribution.

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Pion-nucleon total cross-sections from 0.4 to 0.90 gev/c

Davidson, D. ; Bowen, T. ; Caldwell, P.K. ; et al.
Phys.Rev.D 6 (1972) 1199-1202, 1972.
Inspire Record 73938 DOI 10.17182/hepdata.22266

The total cross sections of π± on protons in the momentum interval from 0.40 to 0.90 GeV/c have been measured with high relative precision. In this interval the statistical error varies between 10 and 20 μb. No new structure is observed.

1 data table match query

No description provided.


Measurement of Polarization in pi-p Elastic Scattering from 229 to 390 MeV

Arens, John F. ; Chamberlain, Owen ; Dost, Helmut E. ; et al.
Phys.Rev. 167 (1968) 1261-1267, 1968.
Inspire Record 944940 DOI 10.17182/hepdata.26509

The polarization parameter in elastic π−p scattering has been measured, at the Berkeley 184-in. synchrocyclotron, with the use of a polarized proton target. At 318-, 337-, and 390-MeV incident pion kinetic energy, the angular range from 70° to 180° in the center-of-mass system was covered. At 229 MeV, polarization measurements were made in the angular range 150° to 180°. Phase-shift analyses, using these and other published data, were made at the two lowest energies.

3 data tables match query

No description provided.

No description provided.

No description provided.


Measurements of the pi- p --> pi0 n Forward Scattering Cross-Section in the Energy Region 400-MeV-600-MeV

Kravtsov, A.V. ; Kuzmin, L.A. ; Nemozhenko, O.N. ; et al.
Nucl.Phys.B 140 (1978) 279-284, 1978.
Inspire Record 135966 DOI 10.17182/hepdata.34984

The forward charge-exchange differential cross section has been measured using two Čerenkov spectrometers at five energies of incident pions. The resulting cross-section values are 4.02 ± 0.22, 3.61 ± 0.13, 4.19 ± 0.13, 3.91 ± 0.12, 3.02 ± 0.14 mb/sr at incident pion energies 400, 450, 500, 550 and 600 MeV, respectively. These values are in a good agreement with dispersion-relation predictions.

1 data table match query

No description provided.


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.


OBSERVATION OF INVERSE ELECTROPRODUCTION OF PIONS ON C-12 NUCLEUS AT 164-MeV PION ENERGY AND DETERMINATION OF F1(v) NUCLEON FORM-FACTOR

Alekseev, G.D. ; Blokhintseva, T.D. ; Karpukhin, V.V. ; et al.
Sov.J.Nucl.Phys. 46 (1987) 801, 1987.
Inspire Record 247868 DOI 10.17182/hepdata.38865

None

1 data table match query

No description provided.