Piccarelli, V.
Pion-Proton Scattering
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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.

5 data tables
Table 1

Measured total cross section. Statistical errors only.

Table 2

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

Table 3

Differential angular distributions of the 2PI0 system for the LH2 data at beam momenta 550 to 678 MeV/c. Statistical errors only.

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Differential cross section of the pion nucleon charge-exchange reaction pi- p --> pi0 n in the momentum range from 148-MeV/c to 323-MeV/c.

The Crystal Ball collaboration Sadler, M.E. ; Kulbardis, A. ; Abaev, V. ; et al.
Phys.Rev.C 69 (2004) 055206, 2004.
Inspire Record 646714 DOI 10.17182/hepdata.31725

Measured values of the differential cross section for pion-nucleon charge exchange are presented at momenta 148, 174, 188, 212, 238, 271, 298, and 323 MeV/c, a region dominated by the Delta resonance. Complete angular distributions were obtained using the Crystal Ball detector at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL). Statistical uncertainties of the differential cross sections are typically 2-6%, exceptions being the results at the lowest momentum and at the most forward measurements of the five lowest momenta. We estimate the systematic uncertainties to be 3-6%.

3 data tables
Table 1

The errors shown are statistical only.

Table 2

The errors shown are statistical only.

Table 3

The total charge-exchange reaction cross section as a function of pion momentum obtained by integrating the differential cross sections. The errors shown are the total and statistical errors.


Measurement of Polarization of Recoil Protons in ( Pi exp - p) Elastic Scattering at 485 Mev

Bekrenev, V. S. ; Gordeev, V. A. ; Kashchuk, A. P. ;
LA-TR-74-33, 2003.
Inspire Record 1113356 DOI 10.17182/hepdata.41626

None

1 data table
Table 1

No description provided.


Production of pi0 and eta mesons at large transverse momenta in pi- p and pi- Be interactions at 515-GeV/c.

The Fermilab E706 collaboration Apanasevich, L. ; Bacigalupi, J. ; Baker, W. ; et al.
Phys.Rev.D 69 (2004) 032003, 2004.
Inspire Record 625447 DOI 10.17182/hepdata.42836

We present results on the production of high transverse momentum pizero and eta mesons in pi-p and pi-Be interactions at 515 GeV/c. The data span the kinematic ranges 1 < p_T < 11 GeV/c in transverse momentum and -0.75 < y < 0.75 in rapidity. The inclusive pizero cross sections are compared with next-to-leading order QCD calculations and to expectations based on a phenomenological parton-k_T model.

19 data tables
Table 1

Invariant differential cross section per nucleon for inclusive PI0 production in PI- BE collisions at 515 GeV averaged over the cm rapidity interval -0.75 to 0.75.

Table 2

Invariant differential cross section for inclusive PI0 production in PI- P collisions at 515 GeV averaged over the cm rapidity interval -0.75 to 0.75.

Table 3

The averaged invariant differential cross section per nucleon as a functionof rapidity in the PT intervals 1.00 to 1.50 and 1.50 to 2.00 GeV for PI0 produ ction in PI- BE interactions at 515 GeV.

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Measurement of the pi- p ---> 3 pi0 n total cross section from threshold to 0.75 GeV/c

Starostin, A. ; Nefkens, B.M.K. ; Manley, D.M. ; et al.
Phys.Rev.C 67 (2003) 068201, 2003.
Inspire Record 620818 DOI 10.17182/hepdata.25279

We report a new measurement of the π−p→3π0n total cross section from threshold to pπ=0.75GeV/c. The cross section near the N(1535)12− resonance is only a few μb after subtracting the large η→3π0 background associated with π−p→ηn. A simple analysis of our data results in the estimated branching fraction B[S11→πN(1440)12+]=(8±2)%. This is the first such estimate obtained with a three-pion production reaction.

1 data table
Table 1

Total cross section from threshold to 750 MeV. Only statistical errors are given in the table.


Experimental study of the near threshold pi+ p ---> pi+ pi+ n cross-section and chiral symmetry

Sevior, M.E. ; Ambardar, A. ; Brack, J.T. ; et al.
Phys.Rev.D 48 (1993) 3987-3995, 1993.
Inspire Record 364198 DOI 10.17182/hepdata.22551

Total cross-section measurements of the π+p→π+π+n reaction at pion kinetic energies of 180, 184, 190, and 200 MeV are reported. The threshold value for the amplitude a(π+π+) as well as the s-wave, isospin 2, ππ scattering length a20 were determined. The results were found to be in agreement with chiral perturbation theory and inconsistent with the calculations of Jacob and Scadron and the model of dominance by quark loop anomalies.

1 data table
Table 1

No description provided.


pi0 and eta meson production in pi+ p and K+ p collisions at 250-GeV/c

The EHS/NA22 collaboration Atayan, M.R. ; Botterweck, F. ; Charlet, M. ; et al.
Z.Phys.C 54 (1992) 247-254, 1992.
Inspire Record 322980 DOI 10.17182/hepdata.14597

We report on a study of inclusiveπ0 and η meson production inπ+p andK+p interactions at 250 GeV/c beam momentum. The Feynman-x spectrum ofπ0 is very similar in shape and normalization to that of negatively charged particles produced in the same experiment. The results are compared with data at other energies and with FRITIOF model predictions. This model overestimates the η cross section by a factor of 2.5. It reproduces theπ0 cross section correctly, but predicts a too hardπ0x distribution.

15 data tables
Table 1

Data from Gamma Detectors only.

Table 2

Data from Gamma Detectors only.

Table 3

Data from RCBC only.

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On the role of rescattering in the production of particles with large transverse momentum in pi- A interactions at 38-GeV/c.

The RISK collaboration Akhobadze, K.G. ; Bannikov, A.V. ; Boos, E.G. ; et al.
Sov.J.Nucl.Phys. 52 (1990) 662-665, 1990.
Inspire Record 299247 DOI 10.17182/hepdata.17239

None

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

PT(P=3,NAME=OUT)**2 - MEAN SQUARE OF THE PROJECTION OF THE ASSOCIATED PARTICLE TRANSVERSE MOMENTUM ONTO THE NORMAL TO THE TRIGGER PARTICLE PRODUCTION PLANE.

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Measurement of the production of high mass gamma gamma, pi0 pi0, and gamma pi0 pairs in pi- p, pi+ p, and p p collisions at 300-GeV/c

De Marzo, C. ; De Palma, M. ; Favuzzi, C. ; et al.
Phys.Rev.D 42 (1990) 748-758, 1990.
Inspire Record 303958 DOI 10.17182/hepdata.22851

The NA24 experiment at CERN investigated inclusive γγ, π0π0, and γπ0 final states in the mass range between 4 and 9 GeV/c2 produced in π−p, π+p, and pp reactions at a c.m.-system energy s=23.7 GeV. The π0π0 cross sections agree well with expectations of the quark-parton model. For γπ0 production in π−p and pp reactions, a clear signal is observed and cross sections are shown. The production of γγ events was observed with a statistical significance of 2.9σ in π−p reactions. The cross section is in agreement with a higher-order QCD prediction.

5 data tables
Table 1

Cross sections are averaged over the transverse momentum differences up to a value which is 1.10 GeV for all points except the first two which are 0.5 and 0.75 GeV respectively.

Table 2

No description provided.

Table 3

Maximum accepted transverse momentum difference of pi0 pair is 1 GeV. Inclusive cross section integrated over the total geometrical acceptance of the detector.

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Neutral kaon production in K+ p and pi+ p interactions at 250-GeV/c

The EHS/NA22 collaboration Ajinenko, I.V. ; Albert, L. ; Belokopytov, Yu. A. ; et al.
Z.Phys.C 46 (1990) 525-536, 1990.
Inspire Record 302184 DOI 10.17182/hepdata.15191

The inclusive production of neutral kaons is studied inK+p and π+p interactions at 250 GeV/c. Total and semi-inclusive cross sections and average kaon multiplicities are presented and compared with the data at lower energies. The longitudinal and transverse momentum distributions and their energy dependence are analyzed. The results are interpreted in the framework of recent parton models.

12 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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