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Observation of Structure in anti-p p and anti-p d Total Cross-Sections Below 1.1-GeV/c

Carroll, A.S. ; Chiang, I.-H. ; Kycia, T.F. ; et al.
Phys.Rev.Lett. 32 (1974) 247, 1974.
Inspire Record 567 DOI 10.17182/hepdata.21309

Total cross sections of p¯p and p¯d have been measured between 360 and 1050 MeV/c, with high statistical precision. Structures are observed in both cross sections at about the same momenta. For p¯p, the central mass is 1932±2 MeV/c2, and a fit to the data with a simple Breit-Wigner resonance plus background gives Γ=9−3+4 MeV/c2. The data suggest that the structures are in the isospin-1 state.

1 data table
Table 1

No description provided.


Polarization structure in p-p elastic scattering,

Abshire, G.W. ; Ankenbrandt, C.M. ; Crittenden, R.R. ; et al.
Phys.Rev.Lett. 32 (1974) 1261-1264, 1974.
Inspire Record 94365 DOI 10.17182/hepdata.21335

We present here the results of an experiment to study the polarization in p−p elastic scattering at the incident momenta 5.15, 7.00, and 12.33 Ge V/c, at t values ranging between - 0.5 and - 6.5 (GeV/c)2. At each momentum we observe a relative maximum in the polarization around t=−1.8 (GeV/c)2. At 12.33 GeV/c the data exhibit a double zero near t=−2.4 (GeV/c)2 and another relative maximum near t=−2.9 (GeV/c)2. The results are discussed in terms of the Chu-Hendry optical model.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Anti-p p annihilations into four charged mesons from 1.6 to 2.2 gev/c

Davidson, J. ; Chapman, J.W. ; Green, R.W. ; et al.
Phys.Rev.D 9 (1974) 77-90, 1974.
Inspire Record 93127 DOI 10.17182/hepdata.21951

The following reactions have been analyzed: (1) p¯p→π−π−π+π+; (2) p¯p→π−π+K−K+; (3) p¯p→K−K−K+K+. Cross sections as a function of beam momentum ranging from 1.6 to 2.2 GeVc are presented. The percentage of resonance production in reaction (1) is examined using the maximum-likelihood (ML) method. The channel is dominated by ρππ and ρf production. The percentage of ρf decreases with p¯ momentum, while ρππ appears to increase. ML fits are also made to reaction (2); the reaction is dominated by K*Kπ, ϕππ, and ρKK production. An enhancement is seen in the Q region of the ππK mass spectrum at 1278 MeV, with FWHM (full width at half maximum) of 25 MeV. Six events are consistent with reaction (3). Mass spectra indicate that five events have at least one ϕ meson produced; one of these is a ϕϕ event.

3 data tables
Table 1

NORMALIZED TO KNOWN TOTAL CROSS SECTION.

Table 2

'FIT 9'. ENERGY DEPENDENCE AND EFFECT OF BOSE-EINSTEIN STATISTICS ALSO STUDIED.

Table 3

'FIT F'.


Updated Charged-Particle Multiplicity Distribution from 205-GeV/c Proton Proton Interactions

Barish, S. ; Cho, Y. ; Colley, D.C. ; et al.
Phys.Rev.D 9 (1974) 2689, 1974.
Inspire Record 609 DOI 10.17182/hepdata.21974

The charged-particle multiplicity distribution in 205−GeVc proton-proton interactions is presented. In addition, the total diffractive contributions to each charged multiplicity are estimated assuming a factorizable Pomeron.

1 data table
Table 1

THE TOTAL CROSS SECTION NORMALIZATION COMES FROM THIS AND OTHER EXPERIMENTS.


Measurements of d p backward elastic scattering at 3.43, 4.50, 5.75, and 6.60 gev/c incident deuteron momentum

Dubal, L. ; Hargrove, C.K. ; Hincks, E.P. ; et al.
Phys.Rev.D 9 (1974) 597-603, 1974.
Inspire Record 93110 DOI 10.17182/hepdata.21938

Differential cross sections for dp elastic scattering from 60° to 175° center of momentum (c.m.) were measured at 3.43, 4.50, 5.75, and 6.60 GeVc incident deuteron momentum. The measurements were made with a two-arm magnetic spectrometer, making use of multiwire proportional chamber detectors. The deuterons were accelerated at the Bevatron of the Lawrence Berkeley Laboratory. Data are compared with predictions of the baryon-pickup model and the one-pion-exchange model. The backward dip at 180° c.m. for 4.5 GeVc, predicted by Craigie and Wilkin using the one-pion-exchange model, is not observed, but reasonable fits to the momentum variation and angular distributions are found. When the data are plotted against the variable Δ of the baryon-pickup model, the s dependence is greatly reduced.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Study of k+ p ---> k0 delta++(1236), k- p ---> anti-k0 n, and k- p ---> anti-k0 delta0(1236)

Foley, K.J. ; Love, W.A. ; Ozaki, S. ; et al.
Phys.Rev.D 9 (1974) 42-48, 1974.
Inspire Record 93128 DOI 10.17182/hepdata.21955

We have studied the reactions K+p→K0Δ++(1236) at 15.7 GeVc, K−p→K¯0n at 10.7 and 15.7 GeVc, and K−p→K¯0Δ0(1236) at 15.7 GeVc in the BNL Double Vee Magnetic Spectrometer. The π+ and π− from the decays of forward K0's were detected and the above reactions were identified by a missing-mass technique. Total and differential cross sections are presented for the first two reactions and a total cross section for the third.

4 data tables
Table 1

Axis error includes +- 10/10 contribution.

Table 2

Axis error includes +- 10/10 contribution.

Table 3

Axis error includes +- 10/10 contribution.

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Differential cross-section for backward pi+ p scattering from 3.25 to 10 gev/c

Bashian, A. ; Finocchiaro, G. ; Good, M.L. ; et al.
Phys.Rev.D 9 (1974) 3193-3196, 1974.
Inspire Record 94286 DOI 10.17182/hepdata.21973

We present differential cross-section data for the reaction π+p→π+p near 180° in the center-of-mass system at beam momenta between 3.25 GeVc and 10 GeVc.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


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
Table 1

Axis error includes +- 6/6 contribution.

Table 2

Axis error includes +- 6/6 contribution.

Table 3

No description provided.


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.

6 data tables
Table 1

Axis error includes +- 6/6 contribution.

Table 2

Axis error includes +- 4.5/4.5 contribution.

Table 3

Axis error includes +- 4.2/4.2 contribution.

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Negative-pion photoproduction from neutrons by linearly polarized photons in the first resonance region

Kondo, K. ; Miyachi, T. ; Ukai, K. ; et al.
Phys.Rev.D 9 (1974) 529-533, 1974.
Inspire Record 93115 DOI 10.17182/hepdata.21954

The angular dependence of the asymmetry for negative-pion photoproduction on neutrons by linearly polarized photons has been measured for photon energies 260, 300, 350, 400, 450, and 500 MeV at center-of-mass angles 60°, 75°, 90°, 150°, and 120°. The results are compared with theoretical models of low-energy single-pion photoproduction. The observed asymmetry below 400 MeV shows good agreement with predictions of dispersion-theoretical models by Berends, Donnachie, and Weaver and by Schwela. The asymmetry values in the 400-500 MeV energy region suggest that smaller M1− amplitude is more favorable.

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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