Bonner, B.E
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Threshold Measurement of the Reaction $\bar{p} p \to \bar{\ell}$ambda $\lambda$ at {LEAR}

Barnes, P.D. ; Besold, R. ; Birien, P. ; et al.
Phys.Lett.B 229 (1989) 432-438, 1989.
Inspire Record 280159 DOI 10.17182/hepdata.29780

The excitation function of the reaction p p→ Λ Λ in the threshold region has been measured at LEAR. Sixteen measurements of the total cross section, in the energy range between 0.85 MeV below threshold and 4.05 MeV above, are presented. The shapes of the measured differential cross sections indicate a remarkably strong p-wave contribution even down to the reaction threshold. We also report here the measurement of significant polarizations in the threshold region; these are compared with previous higher-energy data.

3 data tables
Table 1

Data to be supplied by authors.

Table 2

No description provided.

Table 3

No description provided.


Analyzing Power Measurement in Inclusive $\pi^0$ Production at High $\chi_F$

Bonner, B.E. ; Buchanan, J.A. ; Carey, D.C. ; et al.
Phys.Rev.Lett. 61 (1988) 1918, 1988.
Inspire Record 269386 DOI 10.17182/hepdata.2928

The analyzing power AN in inclusive π0 production has been measured with use of the new 185-GeV/c Fermilab polarized proton beam. We obtain the value AN=0.10±0.03 for π0's in the kinematic region 0.2<xF<0.8 and 0.3<pT<1.2 GeV/c. In certain models of particle production this suggests that the spin of the proton is carried by its valence quarks.

7 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

Individual polarisation measurements.

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Spin Parameter Measurements in $\Lambda$ and $K_S$ Production

Bonner, B.E. ; Buchanan, J.A. ; Clement, J.M. ; et al.
Phys.Rev.D 38 (1988) 729-741, 1988.
Inspire Record 268865 DOI 10.17182/hepdata.23270

The Brookhaven Alternating Gradient Synchrotron polarized proton beam incident on a beryllium target was used for inclusive Λ production at beam momenta of 13.3 and 18.5 GeV/c. The beam polarization was transverse to the beam direction with magnitude 0.63 at 13.3 GeV/c and 0.40 at 18.5 GeV/c. The Λ polarization was measured and found to be in agreement with results from earlier experiments which used unpolarized proton beams. Analyzing power AN and spin transfer DNN of the Λ’s were both measured and compared with a hyperon-polarization model in which the polarization arises from a Thomas-precession effect. There is good agreement with its predictions: AN=0 and DNN=0. In particular, our measurement of 〈DNN〉=-0.009±0.015 supports the idea that the valence quarks carry all of the hadron spin, since this assumption is implicit in the model’s use of SU(6) wave functions to form final-state hadrons from beam fragments and sea quarks. The presence of substantial KS samples at both beam momenta and Λ¯’s at 18.5 GeV/c prompted a measurement of their analyzing powers, which yielded AN(KS)=-0.094±0.012 at 13.3 GeV/c beam momentum and -0.076±0.015 at 18.5 GeV/c, and AN(Λ¯)=0.03±0.10.

15 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Study of the Reaction $\bar{p} p \to \bar{\Lambda} \Lambda$ Near Threshold

Barnes, P.D. ; Besold, R. ; Birien, P. ; et al.
Phys.Lett.B 189 (1987) 249-253, 1987.
Inspire Record 244883 DOI 10.17182/hepdata.30178

Results are presented from a study of the reaction p p→ Λ Λ near threshold. Over 3000 events recorded at s values 14.6 and 25.5 MeV above the Λ Λ threshold (2231.2 MeV) have been analysed. Results for the production cross section, differential cross section, and the Λ and Λ polarization are given at both energies and are compared with recent theoretical calculations of this process.

3 data tables
Table 1

Statistical errors only.

Table 2

No description provided.

Table 3

No description provided.


TRANSVERSE SPIN DEPENDENCE OF THE P P TOTAL CROSS-SECTION DELTA sigma-t FROM 0.8-GEV/C TO 2.5-GEV/C

Madigan, W.P. ; Bell, D.A. ; Buchanan, J.A. ; et al.
Phys.Rev.D 31 (1985) 966-975, 1985.
Inspire Record 216906 DOI 10.17182/hepdata.23564

The difference ΔσT=σ(↓↑)-σ(↑↑) between the proton-proton total cross sections for protons in pure transverse-spin states, was measured at incident momenta 0.8 to 2.5 GeV/c in experiments performed at the Los Alamos Clinton P. Anderson Meson Physics Facility and the Argonne Zero Gradient Synchrotron. In agreement with other data, peaks were observed at center-of-mass energies of 2.14 and 2.43 GeV/c2, where D21 and G41 dibaryon resonances have been proposed.

2 data tables
Table 1

DATA FROM LAMPF EXPERIMENT.

Table 2

DATA FROM ARGONNE EXPERIMENT.


THE ENERGY DEPENDENCE OF THE 90-degrees P P ELASTIC SCATTERING DEPOLARIZATION PARAMETER AND AMPLITUDES BETWEEN 0.9-GEV/C AND 1.5-GEV/C

Hollas, C.L. ; Cremans, D.J. ; Ransome, R.D. ; et al.
Phys.Lett.B 143 (1984) 343-346, 1984.
Inspire Record 208375 DOI 10.17182/hepdata.30531

The depolarization parameter D NN for pp elastic scattering at θ cm = 90 ° has been measured at twelve momenta between 0.9 and 1.5 GeV/ c . The moduli of the three transversity amplitudes T 1 , T 3 , and T 4 have been extracted from these data and from previous measurements of the differential cross section and spin correlation parameter A NN (90 °). Smooth energy dependence is found for all three amplitude moduli.

1 data table
Table 1

Axis error includes +- 3/3 contribution (DUE TO UNCERTAINTIES IN THE TARGET ANALYSING POWER).


SPIN DEPENDENCE IN NEUTRON PROTON CHARGE EXCHANGE AT 790-MEV

Ransome, R.D. ; Hollas, C.L. ; Riley, P.J. ; et al.
Phys.Rev.Lett. 48 (1982) 781-784, 1982.
Inspire Record 180615 DOI 10.17182/hepdata.20595

The analyzing power A and spin-transfer parameters KNN, KSS, KSL, and KLL have been measured in the np charge-exchange (np→pn) region at 790 MeV. These data provide new and unique information on the spin dependence of the np interaction in the charge-exchange region. Models which explain the charge-exchange peak in the np elastic differential cross section as being due to interference between one-pion exchange and a slowly varying background are in basic agreement with the data.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

USING PHASE-SHIFT VALUES FOR KLS AND KSL.


Precision Measurement of n p Charge Exchange Cross-Section at 647-MeV

Evans, M.L. ; Glass, G. ; Hiebert, J.C. ; et al.
Phys.Rev.Lett. 36 (1976) 497-500, 1976.
Inspire Record 112959 DOI 10.17182/hepdata.21088

The differential cross section for n−p elastic scattering in the angular region 145°<θc.m.<180° has been measured with high statistical accuracy using the monoenergetic neutron beam at Clinton P. Anderson Meson Physics Facility. The results differ significantly from previous Dubna and Princeton-Pennsylvania Accelerator results but agree reasonably well with recent Saclay data except at extreme backward angles.

1 data table
Table 1

No description provided.


Measurement of n p Charge Exchange for Neutron Energies 150-MeV-800-MeV

Bonner, B.E. ; Simmons, J.E. ; Hollas, C.L. ; et al.
Phys.Rev.Lett. 41 (1978) 1200-1203, 1978.
Inspire Record 136397 DOI 10.17182/hepdata.20887

The s and u variations of the np charge-exchange (np→pn) cross section are measured to be relatively smooth and without structure at intermediate energies—in sharp contast to previous results.

1 data table
Table 1

No description provided.


Measurements of k- p ---> anti-k0 n charge-exchange cross-sections at 25 and 35 gev/c

Belousov, V.I. ; Bolotov, B.N. ; Devishev, M.I. ; et al.
Phys.Lett.B 43 (1973) 76-78, 1973.
Inspire Record 84940 DOI 10.17182/hepdata.28127

Results are presented on the reaction K − p → K̄ o n for momenta above 20 GeV/ c . Events were identified by precise measurement of the opening angle in the decay K o → π + π − without using a magnetic field. The cross-section is described by a power energy dependence.

1 data table
Table 1

No description provided.