Date

Measurement of direct photon production at Tevatron fixed target energies.

The Fermilab E706 collaboration Apanasevich, L. ; Bacigalupi, J. ; Baker, W. ; et al.
Phys.Rev.D 70 (2004) 092009, 2004.
Inspire Record 653834 DOI 10.17182/hepdata.42777

Measurements of the production of high transverse momentum direct photons by a 515 GeV/c piminus beam and 530 and 800 GeV/c proton beams in interactions with beryllium and hydrogen targets are presented. The data span the kinematic ranges of 3.5 < p_T < 12 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive direct-photon cross sections are compared with next-to-leading-order perturbative QCD calculations and expectations based on a phenomenological parton-k_T model.

18 data tables

Invariant cross sections per nucleon for P BE collisions at 800 GeV.

Invariant cross sections per nucleon for P BE collisions at 530 GeV.

Invariant cross sections per nucleon for PI- BE collisions at 515 GeV.

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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

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.

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

The errors shown are statistical only.

The errors shown are statistical only.

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

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

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.

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.

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

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


Measurement of the spin rotation parameters R and A in pi- p elastic scattering at 450-MeV and 560-MeV

Abaev, V.V. ; Bazhanov, N.A. ; Bekrenev, V.S. ; et al.
Sov.J.Nucl.Phys. 48 (1988) 852-858, 1988.
Inspire Record 457307 DOI 10.17182/hepdata.17344
3 data tables

No description provided.

No description provided.

No description provided.


Measurement of the spin rotation parameter A+ in the elastic scattering of positive pions on a longitudinally polarized proton target in the second resonance region

The ITEP-PNPI collaboration Alekseev, I.G. ; Bobchenko, B.M. ; Budkovsky, P.E. ; et al.
Phys.Lett.B 351 (1995) 585-590, 1995.
Inspire Record 403317 DOI 10.17182/hepdata.28540

The ITEP-PNPI collaboration presents the first results of the spin rotation parameter A + measurements in the second resonance region. The experiment was performed at the ITEP accelerator at a positive pion beam momentum 1.43 GeV/c for scattering angles θ cm = 127° and 133°. The setup was based on a polarized proton target and a carbon-plate polarimeter. The obtained data is compared with the predictions of the existing partial-wave analyses.

1 data table

No description provided.


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

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

Data from Gamma Detectors only.

Data from Gamma Detectors only.

Data from RCBC only.

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