Single-Pion Production in pp Collisions at 0.95-GeV/c (I)

The COSY-TOF collaboration El-Samad, S.Abd ; Bilger, R. ; Brinkmann, K. -Th. ; et al.
Eur.Phys.J.A 30 (2006) 443-453, 2006.
Inspire Record 725793 DOI 10.17182/hepdata.43429

The single-pion production reactions $pp\to d\pi^+$, $pp\to np\pi^+$ and $pp\to pp\pi^0$ were measured at a beam momentum of 0.95 GeV/c ($T_p \approx$ 400 MeV) using the short version of the COSY-TOF spectrometer. The implementation of a central calorimeter provided particle identification, energy determination and neutron detection in addition to time-of-flight and angle measurements. Thus all pion production channels were recorded with 1-4 overconstraints. The total and differential cross sections obtained are compared to previous data and theoretical calculations. Main emphasis is put on the discussion of the $pp\pi^0$ channel, where we obtain angular distributions different from previous experimental results, however, partly in good agreement with recent phenomenological and theoretical predictions. In particular we observe very large anisotropies for the $\pi^0$ angular distributions in the kinematical region of small relative proton momenta revealing there a dominance of proton spinflip transitions associated with $\pi^0$ $s$- and $d$-partial waves and emphasizing the important role of $\pi^0$ d-waves.

8 data tables

Total cross section measurements.. Errors are mainly systematic.

Measured angular distribution for elastic P P scattering in the CM system normalised to the data in the SAID database (Arndt et al. PR C62,034005(2000). This measurement is made to determine the luminosity.

The measured pion angular distribution in the CM system in the reaction P P --> DEUT PI+.

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Total and differential cross-sections of p + p ---> pi+ + d reactions down to 275-keV above threshold

The GEM collaboration Drochner, M. ; Ernst, J. ; Fortsch, S ; et al.
Phys.Rev.Lett. 77 (1996) 454-457, 1996.
Inspire Record 431032 DOI 10.17182/hepdata.19580

The p+p→π++d reaction is studied at excess energies between 0.275 and 3.86 MeV. Differential and total cross section were measured employing a magnetic spectrometer with nearly 4π acceptance in the center of mass system. The measured anisotropies between 0.008 and 0.29 indicate that the p wave is not negligible even so close to threshold. The data are compared to other data offering no evidence for charge symmetry breaking or time reversal violation. The s-wave and p-wave contributions at threshold are deduced.

1 data table

The CONST is p-wave contribution to the cross section. The differential cross section is fitted usig the relations 4*pi*D(SIG)/D(OMEGA) = SIG + CONST*P2(COS(THETA)), where P2 denotes the Legendre polynomial.


Differential cross sections measurement for the p p --> d pi+ reaction at 850-MeV/c.

The GEM collaboration Betigeri, M. ; Bojowald, J. ; Budzanowski, A. ; et al.
Phys.Rev.C 63 (2001) 044011, 2001.
Inspire Record 551879 DOI 10.17182/hepdata.54884

The present data support a large anisotropy in accordance with phase shift predictions and in contrast to another recent experiment.

4 data tables

Measured deuteron angular distribution in the c.m. system. The errors shown are statistical only and there is an additional 10 PCT systematic uncertainty on the overall normalisation.

Legendre polynomial coefficients from a second order and fourth order fit.

Total cross section from second order fit.

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Pion Production in 650-MeV p-p Collisions

Guzhavin, V.M. ; Kliger, G.K. ; Kolganov, V.Z. ; et al.
Sov.Phys.JETP 19 (1964) 847-854, 1964.
Inspire Record 1387586 DOI 10.17182/hepdata.70070

The angular and energy distributions of pions produced by 650-MeV protons and pion-nucleon correlations were studied using a liquid hydrogen bubble chamber. The present investigation indicates that the experimental angular distributions of neutral and charged pions are consis- tent with the assumption of isotopic spin conservation. The contributions of rrN subsystem states with isospin T 11'N = 7' 2 and % are measured; the contribution of the latter is 72 ± 3%.

1 data table

No description provided.


Cross sections for p p ---> d rho+ from 4.0 to 12.3 gev/c and a search for the delta+

Anderson, H.L. ; Dixit, M. ; Evans, H.J. ; et al.
Phys.Rev.Lett. 26 (1971) 108-112, 1971.
Inspire Record 69063 DOI 10.17182/hepdata.21629

Forward differential cross sections for isospin-1 bosons produced in p+p→d+x+ were measured using a deuteron missing-mass spectrometer at a small angle between 4.0- and 12.3−GeVc incident momentum. Differential cross sections for π+ and ρ+ were extracted from the spectra using phase-space backgrounds. They range from 10.4 to 0.4 μb/sr for π+ and from 1.4 to 0.3 μb/sr for ρ+. A bump near 6 GeVc appears in both dπ and dρ channels. No clear evidence is seen for higher-mass bosons. The possible δ+ cross sections average less than 0.01 μb/sr.

3 data tables

TECHNIQUE USED...ELECTRONIC. TABLE 1.

TECHNIQUE USED...MISSING MASS. BREIT WIGNER USED WITH FIXED WIDTH (150 MEV) AND VARIABLE MASS (LATTER VARIED WITH MOMENTA FROM 715 TO 765 MEV). 6 PERCENT NORMALIZATION ERROR; 20 PERCENT FROM BREIT WIGNER FIT. TABLE 1.

TECHNIQUE USED...MISSING MASS. CROSS-SECTIONS CORRESPOND TO VERY NARROW DELTA (962).


Measurements of the differential cross-section of the reaction p p ---> d pi+ from 3.0 to 5.0 gev/c

Anderson, H.L. ; Larson, D.A. ; Myrianthopoulos, L.C. ; et al.
Phys.Rev.D 9 (1974) 580-596, 1974.
Inspire Record 93111 DOI 10.17182/hepdata.21941

A measurement of the complete differential cross section for the reaction pp→dπ+ at 3.00, 3.20, 3.43, 3.65, 3.83, 4.00, 4.20, and 5.05 GeVc incident proton momentum has been made in an attempt to establish the role of the Δ (1950) in this region. The data show that the previously observed enhancement in the forward cross section between 3 and 4 GeVc due to this isobar is an effect which damps out quickly as the production angle departs from zero degrees, in contrast with the well-known enhancement at 1.35 GeVc, which is evident at all angles. In particular, the one-pion-exchange model is in poor agreement with the extended set of data. A detailed description is given of a novel proportional-wire-chamber system which facilitated the selection of this rather rare reaction from a very high competing background.

3 data tables

Axis error includes +- 6/6 contribution.

Axis error includes +- 6/6 contribution.

No description provided.


Measurement of p+p --> pi++d at 90-degrees and 5 GeVc

Ruddick, K. ; Ratner, L.G. ; Edwards, K.W. ; et al.
Phys.Rev. 165 (1968) 1442-1445, 1968.
Inspire Record 944945 DOI 10.17182/hepdata.26528

The differential cross section for the process p+p→π++d was measured at 5.0 GeVc for a center-of-mass angle of 90°. The experiment was done on the Argonne ZGS with the same apparatus as was used in a recent 90° proton-proton elastic scattering experiment. The extracted proton beam of the ZGS was made to impinge upon a CH2 target. The pion and deuteron were detected by two spectrometers, each containing magnets and a scintillation-counter telescope, in coincidence. The incident beam flux was measured by a radiochemical analysis of the CH2 target. The 90° cross section at 5.0 GeVc was found to be 35±9 nb/sr.

1 data table

No description provided.


Measurement of vector-tensor spin-transfer observables for the reaction H(p(pol.),d(pol.))pi+ between 580-MeV and 1300-MeV.

Furget, C ; Goy, J ; Kox, S ; et al.
Nucl.Phys.A 655 (1999) 495-521, 1999.
Inspire Record 512680 DOI 10.17182/hepdata.36156

The three polarization tensor components of the deuteron produced in the H( p , d )π + reaction have been measured for the first time. The experiment was performed using a vertically polarized proton beam produced by the SATURNE accelerator. The deuteron polarization was measured with the POLDER polarimeter. The three polarizing powers t 20 00 , t 21 00 and t 22 00 and the three spin-transfer observables t 20 11 , t 22 11 and t 22 11 have been extracted at a proton kinetic energy of 580 MeV over a wide angular range and at two fixed center-of-mass angles, 132° and 151°, between 800 and 1300 MeV. The six observables, calculated in the C.M. helicity frame, have been compared with predictions of the most refined partial-wave analyses and also with the predictions of a theoretical coupled-channel model which includes the NN-NΔ transition. The comparison between the data and the theory/partial-wave analyses shows some discrepancies which get worse with increasing proton energy. Adding these data to the world database should improve significantly future partial-wave analyses. The A y 0 analyzing power has also been measured over the same kinematical range. The partial-wave analysis predictions are in good agreement with this observable.

7 data tables

No description provided.

No description provided.

No description provided.

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P P ---> D PI+ REACTION AT 0.8-GEV

Nann, H. ; Iversen, S. ; Kaletka, M. ; et al.
Phys.Lett.B 88 (1979) 257-261, 1979.
Inspire Record 147794 DOI 10.17182/hepdata.27297

Differential cross sections and polarization asymmetries for the reaction p + p → d + π + have been measured at 0.8 GeV. The data has been analyzed within the formalism of Mandl and Regge and the results are compared with the recent coupled channel calculations of Niskanen. It is concluded that at this energy the production of upto f-wave pions is important.

2 data tables

No description provided.

No description provided.


MEASUREMENTS OF SPIN CORRELATION PARAMETER A(NN) AND ANALYZING POWER AT 90-degrees FOR P (polarized) P (polarized) ---> D PI+ BETWEEN 500-MEV AND 800-MEV

Glass, G. ; Bhatia, T.S. ; Hiebert, J.C. ; et al.
Phys.Rev.Lett. 53 (1984) 1984-1987, 1984.
Inspire Record 214991 DOI 10.17182/hepdata.20423

Measurements of the spin observables ANN(90∘) and AN0(90∘) for the reaction pp→dπ+ between 500 and 800 MeV are presented and compared with previous measurements and with predictions from theories and a partial-wave analysis. These are the first available measurements of ANN above 590 MeV.

1 data table

ANALYSING POWER IS POL.POL(NAME=AN0).