HEPData Search

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Left-right Asymmetry in Inverse $\pi^-$ Photoproduction From a Transversely Polarized Proton Target

Kim, G.J. ; Adrian, S.D. ; Arends, J. ; et al.

Phys.Rev.Lett. 56 (1986) 1779-1782, 1986.

Inspire Record 232117 DOI 10.17182/hepdata.20259

Accurate measurements of the left-right asymmetry in π−p→γn at pπ=427−625 MeV/c with a transversely polarized target are reported. Results are compared with the predictions from the Arai and Fujii single-pion photoproduction partial-wave analysis and with data on the inverse process measured with a deuterium target. The agreement is poor, casting doubt on the correctness of the value for the radiative-decay amplitude of the neutral Roper resonance now in use.

5 data tables

Table 1

No description provided.

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MEASUREMENT OF THE VECTOR ASYMMETRY IN pi+ d ELASTIC SCATTERING AT 0.74-GeV/c

Yamauchi, I. ; Fukawa, M. ; Isagawa, S. ; et al.

Phys.Rev.C 35 (1987) 352, 1987.

Inspire Record 219514 DOI 10.17182/hepdata.38532

The vector analyzing power has been measured for π+d elastic scattering at 0.74 GeV/c in the angular range of thetac.m.=40?(de–105°, using a polarized deuteron target in a large aperture spectrometer. A comparison with calculations based on the Glauber model was made.

1 data table

Table 1

Data read from graph. Statistical errors only.

Test of {CP} Invariance in $\Lambda^0$ Decay

The R608 collaboration Chauvat, P. ; Erhan, S. ; Hayes, K. ; et al.

Phys.Lett.B 163 (1985) 273-276, 1985.

Inspire Record 216802 DOI 10.17182/hepdata.49640

In an experiment at the CERN intersecting storage rings with √ s = 31 GeV, we have measured αP , the product of asymmetry parameter and polarization, for Λ 0 's and Λ 0 's produced in p p and pp interactions, respectively. The ratio, (αP) Λ /(αP Λ = −1.04±0.29 , is consistent with the value −1, and constitutes the first test of CP invariance in Λ decay.

1 data table

Table 1

The ratio CONST/CONST is obtained under assumption of POL(LAMBDA) = POL(LAMBDABAR).

Measurement of the Analyzing Power for $p p$ (Polarized) $\to p p$ at $p^-$transverse**2 = 6.5-{GeV}/$c^2$

Cameron, P.R. ; Crabb, D.G. ; DeMuth, G.E. ; et al.

Phys.Rev.D 32 (1985) 3070, 1985.

Inspire Record 216507 DOI 10.17182/hepdata.23543

The spin analyzing power A in 28-GeV/c proton-proton elastic scattering was measured at P⊥2=6.5 (GeV/c)2 using a polarized proton target and a high-intensity unpolarized proton beam at the Brookhaven National Laboratory Alternating Gradient Synchrotron. The result of (24±8)% confirms that the analyzing power is large and rising in the large-P⊥2 region.

1 data table

Table 1

No description provided.

STUDY OF THE POLARIZATION FOR LAMBDA'S PRODUCED IN NUCLEUS-NUCLEUS INTERACTIONS

Anikina, M. ; Golokhvastov, A. ; Iovchev, K. ; et al.

Osaka Polarization 1985:986, 1985.

Inspire Record 220117 DOI 10.17182/hepdata.39500

None

1 data table

Table 1

SECOND REACTION CORRESPONDS TO COLLISIONS OF VARIOUS NUCLEAR PAIRS (C C, C NE, O NE, C CU, C ZR, C PB, O PB), FOR DETAILS SEE: ZP C25, 1. PLAB = 3.7 GEV/A|.

MEASUREMENT OF DECAY PARAMETERS AND POLARIZATION IN INCLUSIVE XI- PRODUCTION FROM K- P INTERACTIONS

Bensinger, J. ; Kirsch, L. ; Lomanno, F.D. ; et al.

Nucl.Phys.B 252 (1985) 561-577, 1985.

Inspire Record 216909 DOI 10.17182/hepdata.33790

We present a measurement of the polarization and decay asymmetry parameters of the Ξ − inclusively produced in the forward direction in K − p interactions at 5 GeV/ c . The Ξ − decay parameters have been determined to be α Ξ = −0.405 ± 0.029 and Φ Ξ = 14.7° ± 16.0° from a sample of 20 865 events. A linear rise of the Ξ − polarization has been seen with respect to the transverse momentum of the Ξ − , reaching a maximum of 49 ± 4% at P ⊥ ∼ 0.50 GeV/ c . The value of α Ξ is consistent with the world average prior to 1975, but below the value measured by two recent experiments.

1 data table

Table 1

No description provided.

A STRONG ENERGY DEPENDENCE OF THE ANALYZING POWER IN THE P P ---> D PI+ REACTION AND THE QUESTION OF AN ISOVECTOR DIBARYON RESONANCE

Bertini, R. ; Arvieux, J. ; Boivin, M. ; et al.

Phys.Lett.B 162 (1985) 77-80, 1985.

Inspire Record 221962 DOI 10.17182/hepdata.30330

The angular distributions of the analyzing power for the pp → dπ + reaction have been measured at seven energies T p = 1.2, 1.4, 1.6, 1.7, 1.8, 2.0 and 2.3 GeV. The data show a strong energy dependence with a structure centered at √ s π d = 2.66 GeV. Possible interpretations are presented in the frame of the OPE model and involving the question of the excitation of a dibaryon resonance.

7 data tables

Table 1

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MEASUREMENT OF P (POLARIZED) P (POLARIZED) ---> P P WITH A 16.5-GEV/C POLARIZED PROTON BEAM

Brown, K.A. ; Bruni, R.J. ; Cameron, P.R. ; et al.

Phys.Rev.D 31 (1985) 3017-3020, 1985.

Inspire Record 220234 DOI 10.17182/hepdata.23579

Using the new Brookhaven Alternating Gradient Synchrotron polarized proton beam and our polarized proton target, we measured the spin-spin correlation parameter Ann in 16.5-GeV/c proton-proton elastic scattering. We found an Ann of (6.1±3.0)% at P⊥2=2.2 (GeV/c)2. We also measured the analyzing power A in two independent ways, providing a good test of possible experimental errors. Comparing our new data with 12-GeV Argonne Zero Gradient Synchrotron data shows no evidence for strong energy dependence in Ann in this medium-P⊥2 region.

1 data table

Table 1

ERROR CONTAINS BOTH SYSTEMATIC AND STATISTICAL UNCERTAINTY.