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.


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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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 $\pi^- p \to \pi^- p \pi^0$ 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.


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.


pi- p Elastic Scattering Near 1400-MeV Center-Of-Mass Energy

Lima, C.A.S. ; Greenberg, M. ;
Rev.Bras.Fis. 6 (1976) 117-125, 1976.
Inspire Record 115853 DOI 10.17182/hepdata.70465

None

3 data tables match query

No description provided.

No description provided.

No description provided.


Measurement of the polarization parameter P in elastic π+p scattering at 335, 370, and 410 MeV

Bekrenev, V.S. ; Beloglazov, Yu.A. ; Gaditskii, V.G. ; et al.
JETP Lett. 35 (1982) 148, 1982.
Inspire Record 1408359 DOI 10.17182/hepdata.70446

None

3 data tables match query

No description provided.

No description provided.

No description provided.


Inelastic scattering of 390 MeV $\pi^+$ mesons from protons

Grigor'ev, E.L. ; Mitin, N.A. ;
Sov.Phys.JETP 10 (1960) 1123-1124, 1960.
Inspire Record 1498642 DOI 10.17182/hepdata.75443

None

1 data table match query

No description provided.


Measures of the differential effective sections $\pi ±p$ to 410 MeV and 490 MeV forwards

Banner, M. ; Detoeuf, J.F. ; Fayoux, M.L. ; et al.
Nuovo Cim.A 50 (1967) 431-448, 1967.
Inspire Record 1185325 DOI 10.17182/hepdata.896

Measurements of π±p elastic differential cross-sections have been performed in the forward direction, using a missing-mass spark chamber spectrometer. The films have been seanned by an automatic apparatus. A phase-shift analysis of the experimental data has been done, leading to three solutions. Various experiments are proposed in order to resolve the ambiguities.

2 data tables match query

No description provided.

No description provided.


Measurement of the polarization parameter in $\pi^{pm}p$ scattering from 356 to 519 MeV/c

Gorn, W. ;
LBL-1320, 1973.
Inspire Record 923202 DOI 10.17182/hepdata.1150

None

6 data tables match query

No description provided.

No description provided.

No description provided.

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Measurement of the pi- p ---> n pi0 and pi- p ---> n gamma differential cross-sections near the resonance p(11)(1460)

Cheze, J.B. ; Codreanu, N. ; Hamel, J.L. ; et al.
Nucl.Phys.B 72 (1974) 365-375, 1974.
Inspire Record 94658 DOI 10.17182/hepdata.7810

The π − p→n γ and π − p→n π ° differential cross sections have been measured for −0.9< cos θ ∗ <−0.45 (θ ∗ c.m. scattering angle) at 475 MeV/ c and 550 MeV/ c incident momenta. The π − p→n γ measurement is a good check of the detailed balance principle in the electromagnetic interactions of hadrons at these energies and is in good agreement with Walker's analysis. On the other hand the π − p→ π °n extrapolated values of 180° allows one to verify that the phases of the A 1 2 and A 3 2 amplitudes are equal.

4 data tables match query

No description provided.

No description provided.

BACKWARD CROSS SECTION ESTIMATED BY LEGENDRE POLYNOMIAL FIT.

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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

No description provided.


Measurement of the differential cross-section for pi- p ---> n pi0 at 317, 452, and 491 mev/c

Berardo, P.A. ; Haddock, R.P. ; Nefkens, B.M.K. ; et al.
Phys.Rev.D 6 (1972) 756-766, 1972.
Inspire Record 73968 DOI 10.17182/hepdata.3558

Seventeen differential cross sections of the pion-nucleon charge-exchange reaction have been measured at total center-of-mass energies of 1245, 1337, and 1363 MeV. Most measurements are based on the neutron-photon coincidence method, using carefully calibrated neutron counters and an efficient, large-area photon detector. The results are used to test the predictions of charge independence, with which they agree. The results also confirm the Ayed-Bareyre-Sonderegger phase-degeneracy hypothesis at θ̃π0=180°.

5 data tables match query

No description provided.

No description provided.

No description provided.

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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.


Analyzing power for pi- p charge exchange in the backward hemisphere from 301-MeV/c to 625-MeV/c and a test of pi N partial wave analyses

Kim, G.J. ; Arends, J. ; Engelage, J. ; et al.
Phys.Rev.D 41 (1990) 733-743, 1990.
Inspire Record 301242 DOI 10.17182/hepdata.22935

The analyzing power of π−p→π0n has been measured for pπ=301−625 MeV/c with a transversely polarized target, mainly in the backward hemisphere. The final-state neutron and a γ from the π0 were detected in coincidence with two counter arrays. Our results are compared with predictions of recent πN partial-wave analyses by the groups of Karlsruhe-Helsinki, Carnegie-Mellon University-Lawrence Berkeley Laboratory (CMU-LBL), and Virginia Polytechnic Institute (VPI). At the lower incident energies little difference is seen among the three analyses, and there is excellent agreement with our data. At 547 MeV/c and above, our data strongly favor the VPI phases, and disagree with Karlsruhe-Helsinki and CMU-LBL analyses, which are the source of the πN resonance parameters given in the Particle Data Group table.

3 data tables match query

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).


DIFFERENTIAL CROSS-SECTION FOR PI- P ---> GAMMA N FROM 427-MEV/C TO 625-MEV/C

Kim, G.J. ; Arends, J. ; Briscoe, W.J. ; et al.
Phys.Rev.D 40 (1989) 244-247, 1989.
Inspire Record 285141 DOI 10.17182/hepdata.23110

Differential cross sections for π−p→γn have been determined from 427 to 625 MeV/c, mainly at 90° and 110° c.m. The data were obtained by combining measurements of the Panofsky ratio in flight with known charge-exchange cross sections. The results are compared with γn→π−p data derived from γd experiments; the difference is typically 30%. The radiative decay amplitudes of neutral πN resonances are therefore uncertain by at least 30%.

3 data tables match query

Charge exchange cross section from PWA.

PI- P --> GAMMA N cross section.

GAMMA N --> PI- P cross section calculated using detailed balance.


$\pi^- P$ 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

No description provided.


Differential Cross-sections for $\pi^+ P$ and $\pi^- P$ Elastic Scattering From 378-{MeV}/c to 687-{MeV}/c

Sadler, M.E. ; Briscoe, W.J. ; Fitzgerald, D.H. ; et al.
Phys.Rev.D 35 (1987) 2718-2735, 1987.
Inspire Record 250023 DOI 10.17182/hepdata.23362

Differential cross sections have been measured for π+p and π−p elastic scattering at 378, 408, 427, 471, 509, 547, 586, 625, 657, and 687 MeV/c in the angular range -0.8<cosθc.m.<0.8. The scattered pion and recoil proton were detected in coincidence using scintillation-counter hodoscopes. A liquid-hydrogen target was used except for measurements at forward angles, in which a CH2 target was used. Statistical uncertainties in the data are typically less than 1%. Systematic uncertainties in acceptance and detection efficiency are estimated to be 1%. Absolute normalization uncertainties are 2–3 % for most of the data. The measurements are compared with previous data and with the results of recent partial-wave analyses. The data are fit with Legendre expansions from which total elastic cross sections are obtained.

13 data tables match query

Normalisation uncertainty = 4.1 pct.

Normalisation uncertainty = 2.1 pct.

Normalisation uncertainty = 3.6 pct.

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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.


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.

No description provided.


PRECISE MEASUREMENT OF THE PION CHARGE EXCHANGE FORWARD DIFFERENTIAL CROSS-SECTION AT 522-MEV/C

Gaille, F.C. ; Highland, V.L. ; Auerbach, L.B. ; et al.
Phys.Rev.D 30 (1984) 2408-2410, 1984.
Inspire Record 215121 DOI 10.17182/hepdata.23596

A precise measurement of the differential cross section at zero degrees for the pion charge-exchange reaction π−p→π0n at pπ=522 MeV/c has been made. The result is dσdΩ (0∘)=4.32±0.11 mb/sr.

1 data table match query

DIFFERENTIAL CROSS SECTION AT THETA = 0.


Differential Cross-Sections for pi- p and pi+ p Elastic Scattering Between 400-GeV/c and 590-MeV/c

Gordeev, V.A. ; Koptev, V.P. ; Kruglov, S.P. ; et al.
Yad.Fiz. 24 (1976) 1144-1151, 1976.
Inspire Record 113036 DOI 10.17182/hepdata.18345

None

10 data tables match query

No description provided.

No description provided.

No description provided.

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MEASUREMENT OF THE ASYMMETRY PARAMETER A IN PI- P ELASTIC AND CHARGE EXCHANGE SCATTERING AT PION ENERGIES T (PI) = 98-MEV, 238-MEV, 292-MEV, AND 310-MEV

Alder, J.c. ; Joseph, C. ; Perroud, J.p. ; et al.
Phys.Rev.D 27 (1983) 1040-1055, 1983.
Inspire Record 192365 DOI 10.17182/hepdata.23839

The asymmetry parameter A in π−p elastic scattering at incident pion laboratory kinetic energies Tπ of 98, 238, and 2922 MeV and in π−p charge-exchange scattering π−p→π0n at Tπ=238, 292, and 310 MeV have been measured over a wide range of scattering angles (typically from about 60° to 130° c.m.) with a polarized proton target. The data have been used in an energy-independent phase-shift analysis to improve the precision of the pion-nucleon phase shifts, to set new limits on violation of isospin conservation in the pion-nucleon S wave, and to confirm significant charge dependence in the P32 wave.

3 data tables match query

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

Axis error includes +- 5/5 contribution (BACKGROUND SUBTRACTION).

Axis error includes +- 5/5 contribution (BACKGROUND SUBTRACTION).


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.


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.


Contribution to the study of the interactions $\pi^{-}$p at 407 and 493 MeV : determination of cross sections of charged tracks, phase shift analysis in the elastic channel.

Derre, J. ;
PhD Thesis, Acad. Sci., Paris, 1969.
Inspire Record 1345881 DOI 10.17182/hepdata.39913

None

1 data table match query

Angular Distribution of Charge Exchange and Inelastic Neutrons in $\pi^- - p$ Interactions at 313 and 371 MeV

Lind, Don L. ; Barish, Barry C. ; Ku, Richard J. ; et al.
Phys.Rev. 138 (1965) B1509-B1517, 1965.
Inspire Record 1186787 DOI 10.17182/hepdata.467

Neutron angular distributions from the charge-exchange (π0n) and inelastic modes (π0π0n,π+π−n) of the π−−p interaction have been investigated at 313 and 371 MeV incident-pion kinetic energy. The data were obtained with an electronic counter system. Elastic and inelastic neutrons were separated in the all-neutral final states by time of flight. At both energies the charge-exchange differential cross section at the forward neutron angles differs from that determined by Caris et al. from measurements of the π0-decay gamma distributions, but generally agrees with the phase-shift-analysis calculations of Roper. The distribution of inelastic neutrons from both modes shows a strong preference for low center-of-mass neutron energies. The distribution of these neutrons does not correspond to that expected from the I=0, π−π interaction (ABC effect) suggested to account for the anomaly in p−d collisions observed by Abashian et al. Finally, all available charge-exchange differential-cross-section data from this and other experiments were combined by at least-squares fit to a Legendre expansion of the form dσdΩ*(cosθπ0*)=Σl=0NalPl(cosθπ0*) with the following results (in mb/sr):

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