Hard exclusive hadron nucleon scattering and color transparency

Heppelmann, S. ; Wu, J.Y. ; Appel, R. ; et al.
Nucl.Phys.A 527 (1991) 581C-583C, 1991.
Inspire Record 327578 DOI 10.17182/hepdata.36761

We present preliminary results on the measurement of a variety of exclusive hadron interactions at center of mass scattering angles of 90°. Data are also presented which show the relative transparency of nuclei to πp and pp elastic scattering in this kinematic range.

3 data tables match query

No description provided.

No description provided.

No description provided.


STUDY OF THE I = 3/2 K- pi- ELASTIC SCATTERING FROM THE REACTION K- p ---> K- pi- p pi+ AT 4.25-GeV/c INCIDENT K- MOMENTUM

Jongejans, B. ; van Meurs, R.A. ; Tenner, A.G. ; et al.
Nucl.Phys.B 67 (1973) 381-394, 1973.
Inspire Record 80765 DOI 10.17182/hepdata.32357

Results on the elastic K − π − scattering have been obtained from a study of the K − π − system in 15 000 events of the type K − p→K − π − p π + at a K − beam momentum of 4.25 GeV/ c . The on-mass-shell values of the spherical harmonic moments of the K − π − scattering angular distribution and the K − π − elastic cross section have been obtained by extrapolation to the pion pole. From these values we determined the s- and p-wave phase shifts δ 0 3 and δ 1 3 as a function of the effective mass of the K − π − system between threshold and 1.25 GeV/ c 2 . The value of | δ 0 3 | is smaller than 17° for all mass values and the existence of a p-wave cannot be neglected. At m K − π − = 1.18 GeV/ c 2 there are two solutions for the phase shifts. On the average, the cross section of the K − π − elastic scattering over the region of the effective mass considered amounts to approximately 2.5 mb.

1 data table match query

The errors are statistical.


$K^- p$ elastic scattering at 2.24 GeV/c

Dickinson, M. ; Miyashita, S. ; Libby, L.Marshall ; et al.
Phys.Lett.B 24 (1967) 596-598, 1967.
Inspire Record 1389623 DOI 10.17182/hepdata.29569

The differential elastic scattering cross section for 2.24 GeV/ c K − p collisions has been measured in film from the Brookhaven 20″ bubble chamber. The total elastic cross section is found to be 6.2 ± 0.7 mb. The exponential dependence on square of the momentum t in (GeV/ c ) 2 is fitted by ( d σ d Ω elastic = (12.4 ± 1.0 mb/sr) exp (7.81 ± 0.25)t . A A fit to a black disc model requires a radius of 0.95 ± 0.05 fm.

1 data table match query

D(SIG)/D(T) was fitted to CONST*EXP(-SLOPE*T).


Single-pion production in pi- p interactions at 2.26 gev/c

Reynolds, B.G. ; Albright, John R. ; Bradley, R.H. ; et al.
Phys.Rev. 184 (1969) 1424-1442, 1969.
Inspire Record 62283 DOI 10.17182/hepdata.26478

We present an analysis of ππN final states obtained from π−p interactions at 2.26 GeV/c. Strong ρ production is present in both final states. In addition, significant nucleon isobar production is observed. We observed the following cross sections: σ(π−π0p)=3.77±0.13 mb, σ(π−π+n)=5.67±0.17 mb, σ(ρ−p)=2.19±0.09 mb, σ(Δ+(1236)π−)=0.30±0.10 mb, σ(N0(1650)π0)=0.49±0.07 mb, σ(ρ0n)=2.89±0.11 mb, σ(Δ−(1236)π+)=0.11±0.06 mb, σ(N+(1470)π−)=0.24±0.06 mb, and σ(N+(1650)π−)=0.45±0.05 mb. The spin-density matrix elements are determined for the ρ0 by interpreting the ρ0 asymmetry as an interference between the resonant P wave and a T=0 S wave. A search for the ε0 in the π+π−n final state failed to yield a direct observation of this effect.

1 data table match query

No description provided.


Two-Charged-Particle Final States from pi-+p Interactions at 2.7 GeVc

Miller, D.H. ; Gutay, L. ; Johnson, P.B. ; et al.
Phys.Rev. 153 (1967) 1423-1442, 1967.
Inspire Record 52271 DOI 10.17182/hepdata.26636

A total of 24 360 events having two charged particles in the final state from π−+p interactions at an incident π− momentum of 2.7 GeVc have been analyzed. The final states π−π+n and π−π0p are found to be dominated by rho-meson production, and in addition, significant N*(1238) production is seen. The partial cross sections for the dominant resonant channels are σ=(pρ−)=(1.3±0.2) mb, σ(nρ0)=(2.3±0.2) mb, and σ[π−N*+(→pπ0)]=(0.5±0.2) mb. The production of the ρ− and ρ0 and the decay of the ρ− agree very well with the predictions of an absorption-modified one-pion-exchange model. The production angular distributions of the ρ0 and ρ− follow an exponential of the form Ae+Bt. The results from a least-squares fit give B(ρ−)=9.32±0.08 (GeVc)−2, B(ρ0)=10.26±0.06 (GeVc)−2. A similar analysis for the elastic-scattering events gave B(el)=7.77±0.05 (GeVc)−2. The ρ0 decay distributions are asymmetric and they have been analyzed using a simple model which includes S−P-wave interference. No clear evidence is seen for a T=0, J=0 resonance at a mass near that of the ρ. The N*(1238) resonance production is found to be in agreement with the ρ-exchange model of Stodolsky and Sakurai. Indication of other resonance production with small cross section is seen, such as A1 and A2 production in the multiple missing neutral events. The masses and widths of the ρ0 and ρ− as a function of the four-momentum transfer squared to the nucleon have been determined.

1 data table match query

No description provided.


Nonstrange Resonance Production in pi+ p Collisions at 2.35, 2.62, and 2.90 GeV/c

Alff-Steinberger, C. ; Berley, D. ;
Phys.Rev. 145 (1966) 1072, 1966.
Inspire Record 50938 DOI 10.17182/hepdata.26629

In an exposure of the Brookhaven National Laboratory 20-in. hydrogen bubble chamber to a separated π+ beam at π+ momenta of 2.35 BeV/c (center-of-mass energy E*=2.30 BeV), 2.62 BeV/c (E*=2.41 BeV), and 2.90 BeV/c (E*=2.52 BeV), we have observed production of the ω0, ρ0, and η0 mesons. The production of the ω0, ρ0, and η0 is often accompanied by simultaneous production of the N*++. The momentum transfer in ω0 and ρ0 production is characteristic of peripheral collisions and suggests a single-particle exchange for the production mechanism. The decay distributions for the ω0, ρ0, and the ρ+ demonstrate the importance of modifying the single-particle-exchange model to include absorptive effects. An upper limit on the two-π decay of the ω0 is set at 2%. The width of the η0 is found to be less than 10 MeV. Elastic-scattering distributions are presented.

1 data table match query

No description provided.


Single and Multiple Pion Production in pi+n and pi-p Interactions at 1.7 GeV/c

Bacon, T.C. ; Fickinger, W.J. ; Hill, D.G. ; et al.
Phys.Rev. 157 (1967) 1263-1278, 1967.
Inspire Record 52416 DOI 10.17182/hepdata.26582

Meson production in π−p and π+n interactions at 1.7 GeV/c has been studied in two bubble-chamber exposures. Combined results are presented with emphasis on single-pion production (4300 events) which is dominated by the formation of the ρ0 meson in peripheral interactions, and on double-pion production (1100 events) which shows strong formation of the ω meson. These data are compared with the predictions of particle-exchange models, including absorption, and the effects of competing channels are discussed. Evidence for a two-pion decay mode of the ω is examined quantitatively. Processes with higher meson multiplicities are described.

1 data table match query

No description provided.


Interactions of pi+ Mesons with Protons at 2.08 BeVc

James, Frederick E. ; Kraybill, Henry L. ;
Phys.Rev. 142 (1966) 896-912, 1966.
Inspire Record 50875 DOI 10.17182/hepdata.26717

Interactions of 2.08−BeVc positive pions with protons have been studied using the 20-in. hydrogen bubble chamber and the alternating gradient synchrotron at Brookhaven National Laboratory. Using 3000 elastic and 8000 inelastic events, the partial cross sections for elastic scattering and for meson production have been measured. The ρ+, ρ0, ω0, and η0 resonances are produced strongly and emerge predominantly in the forward direction in the center-of-mass system, suggesting a peripheral mechanism for their production. The possibility of explaining these reactions by specific particle-exchange models is investigated. More than 75% of the ρ0, ω0, and η0 are produced with the N33* (1238) isobar. The N* (1688) is produced in about one-third of the π+π+N final states. Cross sections for production of ρ+p, π+pω, N33*ω, π+pη, N33*η, π+pρ0, N33*ρ0, N15*π+, and N33*π0, are given. A1, B, φ, and X mesons are not observed.

1 data table match query

No description provided.


pi-p Two-Prong Interactions at 4.16 GeV/c

Eisner, R.L. ; Johnson, P.B. ; Klein, P.R. ; et al.
Phys.Rev. 164 (1967) 1699-1710, 1967.
Inspire Record 52292 DOI 10.17182/hepdata.26569

An analysis of π−p two-prong interactions at 4.16 GeV/c is presented. The total two-prong cross section is 19.11±0.40 mb, based on 33 672 events. The elastic-scattering differential cross section shows an exponential behavior, Kexp(−AΔ2). With A=7.36±0.14 GeV−2, the "absorption parameters" are derived as C+=0.846±0.017 and γ+=0.040±0.001. The final-state π−π0p exhibits a strong ρ−, and the π−π+n a strong ρ0 and f0. The partial cross sections for the dominant resonant channels pρ−, π−Δ+(1236) (→pπ0), ρ0n, and f0n are 0.59±0.03, 0.17±0.01, 1.15±0.05, and 0.53±0.06 mb, respectively. The ρ− production and decay angular distributions do not agree with the predictions of the absorption-modified one-pion-exchange model. However, an inclusion of the contribution from ω exchange adequately accounts for the discrepancy. The ρ0 asymmetry is interpreted as a result of an interference of the resonant P wave and isospin-zero S wave, and the corresponding spin-density matrix elements are obtained. In the final state π−p+neutrals, a clear peak for the η meson and some evidence for the ω meson are seen.

1 data table match query

Axis error includes +- 0.0/0.0 contribution (?////EVENT NORMALIZATION).


Channel cross-sections of k- p reactions from 1.26 to 1.84 gev/c

de Bellefon, A. ; Berthon, A. ; Rangan, L.K. ; et al.
Nuovo Cim.A 7 (1972) 567-583, 1972.
Inspire Record 78277 DOI 10.17182/hepdata.37482

We present the results on total channel cross-sections obtained in the Saclay 180 l HBC exposed to a separated K− beam at Nimrod. The cross-sections for each channel are given at 13 incident K− momenta between 1.26 and 1.84 GeV/c.

1 data table match query

No description provided.