The search for particle electric dipole moments (edm) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known − → v × − → E field with magnetic field gradients (often referred to as the geometric phase effect (Commins, ED; Am. J. Phys. 59, 1077 (1991), Pendlebury, JM et al; Phys. Rev. A70, 032102 (2004)). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic form for the velocity auto-correlation function which determines the velocityposition correlation function which in turn determines the behavior of the frequency shift Phys. Rev A71, 032104 (2005)) and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.

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The general theory of neutron scattering is presented, valid for the whole domain of slow neutrons from thermal to ultracold. Particular attention is given to multiple scattering which is the dominant process for ultracold neutrons (UCN). For thermal and cold neutrons, when the multiple scattering in the target can be neglected, the cross section is reduced to the known value. A new expression for inelastic scattering cross section for UCN is proposed. Dynamical processes in the target are taken into account and their influence on inelastic scattering of UCN is analyzed. PACS.28.20.-v Neutron physics, 61.12.Bt Theories of diffraction and scattering

The study of five-fold (P even, T odd) correlation in the interaction of slow polarized neutrons with aligned nuclei is a possible way of testing the time reversal invariance due to the expected enhancement of T violating effects in compound resonances. Possible nuclear targets are discussed which can be aligned both dynamically as well as by the "brute force" method at low temperature. A statistical estimation is performed of the five-fold correlation for low lying p wave compound resonances of the 121 Sb, 123 Sb and 127 I nuclei. It is shown that a significant improvement can be achieved for the bound on the intensity of the fundamental parity conserving time violating (PCTV) interaction. PACS: 24.80.+y Nuclear tests of fundamental interactions and symmetries

Abstract. Angular distributions of fission fragments from the neutron-induced fission of 232 Th, 233 U, 235 U, 238 U and 209 Bi have been measured in the energy range 1-200 MeV at the neutron TOF spectrometer GNEIS based on the spallation neutron source at 1 GeV proton synchrocyclotron of the PNPI (Gatchina, Russia). The multiwire proportional counters have been used as a position sensitive fission fragment detector. A description of the experimental equipment and measurement procedure is given. The anisotropy of fission fragments deduced from the data on measured angular distributions is presented in comparison with experimental data of other authors, first of all, the recent data from WNR at LANSCE (Los Alamos, USA) and n TOF(CERN).

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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)