Direct reaction test of T violation in 2 MeV neutron scattering from aligned 165Ho

Koster, J.E.; Davis, E. D. D.; Gould, C.R.; Haase, D. G.; Roberson, N. R.; Seagondollar, L. W.; Wilburn, S. W.; Zhu, X.

doi:10.1016/0370-2693(91)90517-t

Cited by 31 publications

(8 citation statements)

References 11 publications

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“…Typical values for the proton-and deuteron-(vector) beam polarization were 0.63 and 0.75, respectively. To cancel instrumental asymmetries in the charged-particle asymmetry and neutron asymmetry measurements, the polarization direction of the polarized ion beam was inverted from up to down and vice versa (relative to the horizontal scattering plane) at a rate of 10 Hz by use of the eight-step sequence + − + + − + −−, which removes instrumental asymmetries in first and second order [17]. A capacitive time-pickoff unit was installed just in front of the neutron production target to derive a fast timing signal from the pulsed ion beam.…”

Section: G Polarized Charged-particle Beamsmentioning

confidence: 99%

Measurements ofAy(θ)forC12
Roper
¹
,
Tornow
²
,
Braun
³

et al. 2005
Phys. Rev. C
8
1
9
0
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The analyzing power A y (θ ) for neutron elastic scattering from 12 C has been measured for 33 neutron energies between E n = 2.2 and 8.5 MeV in the angular range from 25 • to 145 • in the laboratory system. The primary motivation for these measurements is the need for an accurate knowledge of A y (θ) for 12 C(n, n) 12 C elastic scattering to enable corrections to high-precision neutron-proton and neutron-deuteron A y (θ) data in the neutronenergy range below E n = 30 MeV. In their own right, 12 C(n, n) 12 C A y (θ) data are of crucial importance for improving both the parametrization of n-12 C scattering and our knowledge of the level scheme of 13 C. The present A y (θ ) data are compared with published data and previous phase-shift-analysis results.

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Section: G Polarized Charged-particle Beamsmentioning

confidence: 99%

Measurements ofAy(θ)forC12
Roper
¹
,
Tornow
²
,
Braun
³

et al. 2005
Phys. Rev. C
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“…2 were fitted by Eq. (14) modified to in- elude Doppler and resolution broadening. The free parameters in the fit were the energy shift AE P \ and the mixing ratio of the g n (\ j ) and g n (\ j) amplitudes studied earlier by Alfimenkov et al [17].…”

Section: E ~ H P 2~ 11 P 2/mentioning

confidence: 99%

“…The experimental upper limit on <p is between 10 ~3 and 10 ~4, e.g., as given in Ref. [9] or in the recent aligned target experiment [14]. Therefore, in the framework of Bunakov's hypothesis, any experimental measurement of p near a p-wave resonance with accuracy better than 10 _1 may decrease this limit.…”

mentioning

confidence: 96%

TestingT-odd,P-even interactions with γ rays from neutronp-wave resonances

et al. 1993

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A new method for the study of time reversal violation is described. It consists of measurements of the forward-backward asymmetry in individual gamma-ray transitions resulting from unpolarized neutron capture in p-wave resonances. An experiment with a 1,3 Cd target performed at the Dubna pulsed neutron source has been analyzed and a limit on the time reversal odd, parity even interaction extracted. The possibility of experiments using the powerful pulsed neutron source at Los Alamos is considered.PACS numbers: 25.40.Ny, 1 UO.Er CP nonconservation or T (time reversal) noninvariance was observed in the decay of neutral kaons long ago [1]. Attempts to search for this phenomenon in other processes have failed. Recently some possible tests using neutron optics experiments were discussed in a paper by Weidenmuller [2] and references therein. Interest in the neutron-nucleus interaction was stimulated by the discovery [3,4] of large P-(parity-) nonconserving effects near neutron p-wave resonances. These effects appeared to be enhanced by 3 to 6 orders of magnitude compared to the single-particle estimate Gm£ -10~7 (in units of h =c = 1 and G = \0~5m p~2 ).The enhancement was explained in terms of the P-nonconserving mixing of compound nuclear states with opposite parity (mixing of the p-wave resonance with the nearest s-wave resonances [5,6]). The concept of the spreading width of the weak interaction was brought into practice based on recent experimental results [7], It was shown by Bunakov and Gudkov [8,9] that possible T-noninvariant effects may be enhanced near p-wave resonances in the same manner as P-nonconserving effects. It has been suggested that a serach be made for P-conserving, T-noninvariant effects in polarized neutron transmission through aligned nuclear targets [10][11][12]. Such an effect would occur due to an s-[kxlKkl) term in the neutron-nucleus elastic forward scattering amplitude. Here s and I are the neutron and nucleus spins and k is neutron momentum. Bunakov [9] showed that the maximum value of the experimental polarization asymmetry in the cross section p is connected to the Tnoninvariant matrix element vj and to the /7-wave resonance level spacing D p by the approximate relation P^vJ/Dp.(1)

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“…The search for the effects of direct violation of the Time Reversal Invariance (TRI) and the related theoretical studies still remain to be a very actual direction of nuclear physics [1][2][3][4][5][6][7][8][9][10][11][12], [13][14][15][16][17][18][19][20][21][22][23]. Different kinds of experiments (nuclear, atomic and molecular) are competing in this field to obtain the tighter bounds on the TRI violating interaction.…”

mentioning

confidence: 99%

“…Engel, Gould and Hnizdo [7] used the interaction V T RIV ρ to obtain the effective TRI violating nuclear optical potential. That enabled them to calculate microscopically the "fivefold" TRIV correlation ( s · I × p)( I · p) and, by comparison of the result to the experimental value for the neutron scattering on the aligned 165 Ho target [21], to extract the limits on the value of the constantḡ ρ .…”

mentioning

confidence: 99%

Limits of time-reversal violating interaction from compound nuclear experiments

Vorov

1996

Physics Letters B

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Mean square matrix elements of the time reversal invariance violating (TRIV) interaction between the compound nuclear states are calculated within the statistical model, using the explicit form of the TRIV interaction via the ρmeson exchange. From the comparison of the calculated values with the data known for p + 27 Al ⇔ 24 M g + α reaction, and for γ-correlation measurements in 113 Cd(n, γ) 114 Cd process, the bounds on the TRIV constant are obtained g ρ < ∼ 1.8 × 10 −2 andḡ ρ < ∼ 1.1 × 10 −2 . The sensitivity of the recently proposed detailed balance test experiments on isolated resonances in 32 S to the value ofḡ ρ is shown to be as high as to reach valuesḡ ρ ∼ 10 −4 .

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Direct reaction test of T violation in 2 MeV neutron scattering from aligned 165Ho

Cited by 31 publications

References 11 publications

Measurements ofAy(θ)forC12
Roper
¹
,
Tornow
²
,
Braun
³

et al. 2005
Phys. Rev. C
8
1
9
0
View full text Add to dashboard Cite

Measurements ofAy(θ)forC12
Roper
¹
,
Tornow
²
,
Braun
³

et al. 2005
Phys. Rev. C
8
1
9
0
View full text Add to dashboard Cite

TestingT-odd,P-even interactions with γ rays from neutronp-wave resonances

Limits of time-reversal violating interaction from compound nuclear experiments

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Direct reaction test of T violation in 2 MeV neutron scattering from aligned 165Ho

Cited by 31 publications

References 11 publications

Measurements ofAy(θ)forC12Roper1, Tornow2, Braun3 et al. 2005Phys. Rev. C8190View full textAdd to dashboardCite

Measurements ofAy(θ)forC12Roper1, Tornow2, Braun3 et al. 2005Phys. Rev. C8190View full textAdd to dashboardCite

TestingT-odd,P-even interactions with γ rays from neutronp-wave resonances

Limits of time-reversal violating interaction from compound nuclear experiments

Contact Info

Product

Resources

About

Measurements ofAy(θ)forC12
Roper
¹
,
Tornow
²
,
Braun
³

et al. 2005
Phys. Rev. C
8
1
9
0
View full text Add to dashboard Cite

Measurements ofAy(θ)forC12
Roper
¹
,
Tornow
²
,
Braun
³

et al. 2005
Phys. Rev. C
8
1
9
0
View full text Add to dashboard Cite