Precision measurement of charge symmetry breaking in n p elastic scattering at 347-MeV

Zhao, J. ; Abegg, R. ; Berdoz, A.R. ; et al.
Phys.Rev.C 57 (1998) 2126-2141, 1998.
Inspire Record 484066 DOI 10.17182/hepdata.25692

A nonzero difference of the analyzing powers due to charge symmetry breaking has been measured with high precision in np elastic scattering at a neutron beam energy of 347 MeV. The neutron beam and proton target were alternately polarized for the measurements of An and Ap. A mirror-symmetric detection system was used to cancel geometry-related systematic errors. From fits of the measured asymmetry angular distributions over the range of 53.4°<~θcm<~86.9°, the difference in the zero-crossing angles of the analyzing powers was determined to be 0.438°±0.054°(stat.)±0.051°(syst.) in the center-of-mass system. Using the experimentally determined slope of the analyzing power dA/dθ=(−1.35±0.05)×10−2 deg−1 (c.m.), this is equivalent to ΔA≡An−Ap=[59±7(stat.)±7(syst.)±2(syst.)]×10−4. The shape of ΔA(θ) in the vicinity of the zero-crossing angle has also been extracted. Predictions of nucleon-nucleon interaction models based on meson exchange agree well with the results.

1 data table

(C=N) or (C=P) stands for polarized beam or target.


Neutron-proton differential cross-section measurements for En from 28 to 75 MeV

Benck, S. ; Slypen, I. ; Meulders, J-P. ; et al.
Nucl.Phys.A 615 (1997) 220-228, 1997.
Inspire Record 459311 DOI 10.17182/hepdata.36360

Experimental measurements of differential cross-sections for neutron-proton scattering are reported for 12 incident neutron energies between 28 and 75 MeV. Data are compared with predictions of different theoretical models and with other experimental results.

6 data tables

No description provided.

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The Zero crossing angle of the n - p analyzing power

Davis, C.A. ; Abegg, R. ; Berdoz, A.R. ; et al.
Phys.Rev.C 53 (1996) 2052-2067, 1996.
Inspire Record 402498 DOI 10.17182/hepdata.26459

The angles at which the n-p elastic scattering neutron analyzing power A00n0 crosses zero were measured with precision at four TRIUMF energies below 300 MeV. The mean interaction energies are also measured with greater precision than in previous experiments. The results are En=175.26±0.23 MeV, θzx=98.48°±0.28°; En=203.15±0.20 MeV, θzx=91.31°±0.18°; En=217.24±0.19 MeV, θzx=87.64°±0.18°; and En=261.00±0.16 MeV, θzx=80.18°±0.19°. After correction for charge symmetry breaking effects, the energy where the averaged neutron-proton analyzing power crosses zero at θzx=90° is found to be En=206.8±0.6 MeV. © 1996 The American Physical Society.

4 data tables

Polarized beam and target.

Polarized beam and target.

Polarized beam and target.

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Measurement of spin-dependent total cross-section difference $\Delta\sigma_T$ in neutron-proton scattering at 16 MeV

Broz, J. ; Cerny, J. ; Dolezal, Z. ; et al.
Z.Phys.A 354 (1996) 401, 1996.
Inspire Record 397734 DOI 10.17182/hepdata.31421

A new measurement of $\Delta\sigma_T$ for polarized neutrons transmitted through a polarized proton target at 16.2 MeV has been made. A polarized neutron beam was obtained from the $^{3}\rm{H}(d,\vec n)^{4}\rm{He}$ reaction; proton polarization over 90\% was achieved in a frozen spin target of 20 cm$^3$ volume. The measurement yielded the value $\Delta\sigma_T=(-126\pm21\pm14)$ mb. The result of a simple phase shift analysis for the $^3S_1-^3D_1$ mixing parameter $\epsilon_1$ is presented and compared with the theoretical potential model predictions.

1 data table

No description provided.


n p elastic analyzing power A(NO) and spin transfer K(NN)

McNaughton, M.W. ; Johnston, K. ; Swenson, D. ; et al.
Phys.Rev.C 48 (1993) 256-265, 1993.
Inspire Record 34401 DOI 10.17182/hepdata.51045

We have measured the analyzing power ANO and the spin transfer KNN for np-elastic scattering from about 60° to 170° c.m. at 485, 635, and 788 MeV. The new data clarify previous discrepancies and complete the first-order determination of nucleon-nucleon elastic scattering at these energies.

6 data tables

For definition of the POL(NAME=SPIN-TRANSFER) see text.

For definition of the POL(NAME=SPIN-TRANSFER) see text.

For definition of the POL(NAME=SPIN-TRANSFER) see text.

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Differential cross-section for n p elastic scattering in the angular region 50-degrees < Theta* < 180-degrees at 459-MeV

Northcliffe, L.C. ; Jain, M. ; Evans, M.L. ; et al.
Phys.Rev.C 47 (1993) 36-46, 1993.
Inspire Record 358672 DOI 10.17182/hepdata.26016

The differential cross section for n-p elastic scattering at 459 MeV in the c.m. angular region 50°<θ*<180° has been measured with high statistical precision and good relative accuracy. The uncertainty in the absolute normalization (based on the simultaneously measured yield of deuterons from the np→dπ0 reaction) was initially estimated to be ∼7%. The results agree well with back-angle data obtained independently at LAMPF but less well with results from Saclay and the Princeton-Pennsylvania Accelerator and, except for a normalization difference of 10%, are fairly well represented by a phase-shift fit. The pole-extrapolation method of Chew was used to extract the pion-nucleon coupling constant f2 from the back-angle portion of the data. The value obtained, f2=0.069, is somewhat smaller than the values 0.0735–0.0790 obtained from analyses of pion-nucleon scattering, tending to confirm the need for an upward renormalization of the angular distribution by ∼10%.

1 data table

No description provided.



Differential Cross-sections and Analyzing Powers for Small Angles $N P$ Elastic Scattering Between 376-{MeV} and 1135-{MeV}

Silverman, B.H. ; Lugol, J.C. ; Saudinos, J. ; et al.
Nucl.Phys.A 499 (1989) 763-788, 1989.
Inspire Record 264337 DOI 10.17182/hepdata.36902

We have measured absolute differential cross sections and analyzing powers for neutron-proton elastic scattering for momentum transfer 0.01 < | t |< 0.08 (GeV/ c ) 2 at several energies between 378 and 1135 MeV. The ionization chamber IKAR filled with methane was used as both a gas target and recoil detector. For the analyzing-power measurements the scattered neutron was detected in scintillation counters in coincidence with the recoil proton detected in IKAR. Special care was taken to ensure a precise absolute normalization of the cross sections, with overall systematic uncertainties of 4–7%.

19 data tables

TOTAL SYSTEMATIC UNCERTAINTIES IN D(SIG)/D(T)=6.4 PCT.

TOTAL SYSTEMATIC UNCERTAINTIES IN D(SIG)/D(T)=5.4 PCT.

TOTAL SYSTEMATIC UNCERTAINTIES IN D(SIG)/D(T)=6.5 PCT.

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Measurement of C(ll) and C(sl) in $N P$ Elastic Scattering at 484-{MeV} and 634-{MeV}

Burleson, G.R. ; Faucett, J.A. ; Fontenla, C.A. ; et al.
Phys.Rev.Lett. 59 (1987) 1645, 1987.
Inspire Record 21907 DOI 10.17182/hepdata.3247

The spin-spin correlation parameters CLL=(L,L;0,0)=ALL and CSL=(S,L;0,0)=ASL for np elastic scattering were measured for incident polarized-neutron–beam kinetic energies of 484 and 634 MeV over the center-of-mass angles from ≃80° to 180°. The data are important for determining the I=0 nucleon-nucleon amplitudes. These results are compared with phase-shift calculations.

5 data tables

No description provided.

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Cross-sections of $N P$ Interaction Channels at $P (N$) = 1-{GeV}/c. - 5-{GeV}/c. (In Russian)

Besliu, C. ; Gruia, S. ; Ierusalimov, A.P. ; et al.
Sov.J.Nucl.Phys. 43 (1986) 565-568, 1986.
Inspire Record 238221 DOI 10.17182/hepdata.17455

None

5 data tables

No description provided.

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