@inbook{davis_2021, title={Cross Section Correlation Functions and Deviations from the Porter-Thomas Distribution}, url={https://doi.org/10.1007/978-3-030-58082-7_6}, DOI={10.1007/978-3-030-58082-7_6}, abstractNote={The long-held belief that, in a compound nucleus (CN), fluctuations in transition strengths are drawn from a Porter-Thomas distribution (PTD), i.e., a χ2 distribution of one degree of freedom has been challenged by work done post-1990 at the Los Alamos Neutron Science Center and Oak Ridge Electron Linear Accelerator facilities. To date, the focus has been on data taken in the resolved resonance regime. I put forward arguments in support of the analysis of measurements of the total cross section in the unresolved but not strongly overlapping resonance regime.}, author={Davis, Edward D.}, year={2021} }
 @article{davis_young_2017, title={Neutron-antineutron oscillations beyond the quasifree limit}, volume={95}, ISSN={2470-0010 2470-0029}, url={http://dx.doi.org/10.1103/physrevd.95.036004}, DOI={10.1103/physrevd.95.036004}, abstractNote={Prompted by plans to conduct a new neutron oscillation experiment at the European Spallation Source (ESS), we consider issues associated with the magnetic field that must be present, some of which are potentially exacerbated by the significantly larger length $l$ contemplated for the neutron propagation region. To this end, we introduce a stochastic model of the residual magnetic field within the propagation region which draws on features of magnetic profiles measured during the last free neutron oscillation experiment [conducted at the Institut Laue-Langevin (ILL) in the 1990's]. We average over both fluctuations in the magnetic field sampled by neutrons, and representative spectra of neutron speeds. We find that deviations from the quasi-free result for the antineutron probability do not depend quadratically on $l$ (as a naive perturbative estimate would suggest) but increase only linearly with $l$. As regards the large spikes in the magnetic field which can be expected at, for example, joints in the magnetic shielding of the propagation region (despite compensating currents and magnetic idealization of the shield), we demonstrate that their effect scales as $l/D^{3/2}$, where $D$ is the diameter of the cylindrical magnetic shielding. Our arguments suggest that, provided the dimensions of the propagation region are such that the ratio $l/D^{3/2}$ does not exceed the value pertinent to the ILL experiment, and these spikes occur close to either end of the propagation region, they can be neglected. We also establish that any large magnetic field encountered after the propagation region is exited will not diminish the probability for antineutron detection. For the range of values of $l$ of most interest to the ESS experiment, it should suffice to improve on the level of magnetic suppression achieved at the ILL by a factor of two.}, number={3}, journal={Physical Review D}, publisher={American Physical Society (APS)}, author={Davis, E. David and Young, Albert R.}, year={2017}, month={Feb} }
 @article{davis_hamdan_2015, title={Reappraisal of the limit on the variation in α implied by the Oklo natural fission reactors}, volume={92}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.92.014319}, DOI={10.1103/physrevc.92.014319}, abstractNote={Methods: We point out that, with more appropriate choices of nuclear parameters, the standard estimate (due to Damour and Dyson) of the sensitivity for resonances in 150 Sm is increased by a factor of 2.5. We go on to identify and compute excitation, Coulomb and deformation corrections. To this end, we use deformed Fermi density distributions fitted to the output of Hartee-Fock (HF) + BCS calculations (with both the SLy4 and SkM ∗ Skyrme functionals), the energetics of the surface diffuseness of nuclei, and thermal properties of their deformation. We also invoke the eigenstate thermalization hypothesis, performing the requisite microcanonical averages with two phenomenological level densities which, via the leptodermous expansion of the level density parameter, include the effect of increased surface diffuseness. Theoretical uncertainties are assessed with the inter-model prescription of Dobaczewski et al. [J. Phys. G: Nucl. Part. Phys. 41, 074001 (2014)]. Results: The corrections diminish the revised 150 Sm sensitivity but not by more than 25%. Subject to a weak and testable restriction on the change in mq/� (relative to the change in α) since the time when the Oklo}, number={1}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, Edward D. and Hamdan, Leila}, year={2015}, month={Jul}, pages={014319} }
 @article{davis_2014, title={Implications of the Oklo Phenomenon in a Chiral Approach to Nuclear Matter}, volume={56}, ISSN={0177-7963 1432-5411}, url={http://dx.doi.org/10.1007/s00601-014-0909-0}, DOI={10.1007/s00601-014-0909-0}, abstractNote={It has been customary to use data from the Oklo natural nuclear reactor to place bounds on the change that has occurred in the electromagnetic fine structure constant α over the last 2 billion years. Alternatively, an analysis could be based on a recently proposed expression for shifts in resonance energies which relates them to changes in both α and the average m q of the u and d current quark masses, and which makes explicit the dependence on mass number A and atomic number Z. (Recent model independent results on hadronic $${\sigma}$$ -terms suggest sensitivity to the strange quark mass is negligible.) The most sophisticated analysis, to date, of the quark mass term invokes a calculation of the nuclear mean-field within the Walecka model of quantum hadrodynamics. We comment on this study and consider an alternative in which the link to low-energy quantum chromodynamics and its pattern of chiral symmetry-breaking is more readily discernible. Specifically, we investigate the sensitivity to changes in the pion mass $${M_\pi}$$ of a single nucleon potential determined by an in-medium chiral perturbation theory ( $${\chi}$$ PT) calculation which includes virtual $${{\Delta}}$$ -excitations. Subject to some reasonable assumptions about low-energy constants, we confirm that the m q -contribution to resonance shifts is enhanced by a factor of 10 or so relative to the $${\alpha}$$ -term and deduce that the Oklo data for Sm imply that $${|m_q({\rm Oklo})- m_q({\rm now})| \lesssim 10^{-9}m_q({\rm now})}$$ .}, number={6-9}, journal={Few-Body Systems}, publisher={Springer Science and Business Media LLC}, author={Davis, Edward D.}, year={2014}, month={Sep}, pages={431–437} }
 @article{davis_gould_sharapov_2014, title={Oklo reactors and implications for nuclear science}, volume={23}, ISSN={0218-3013 1793-6608}, url={http://dx.doi.org/10.1142/s0218301314300070}, DOI={10.1142/s0218301314300070}, abstractNote={ We summarize the nuclear physics interests in the Oklo natural nuclear reactors, focusing particularly on developments over the past two decades. Modeling of the reactors has become increasingly sophisticated, employing Monte Carlo simulations with realistic geometries and materials that can generate both the thermal and epithermal fractions. The water content and the temperatures of the reactors have been uncertain parameters. We discuss recent work pointing to lower temperatures than earlier assumed. Nuclear cross-sections are input to all Oklo modeling and we discuss a parameter, the 175 Lu ground state cross-section for thermal neutron capture leading to the isomer 176 m  Lu , that warrants further investigation. Studies of the time dependence of dimensionless fundamental constants have been a driver for much of the recent work on Oklo. We critically review neutron resonance energy shifts and their dependence on the fine structure constant α and the ratio Xq = mq/Λ (where mq is the average of the u and d current quark masses and Λ is the mass scale of quantum chromodynamics (QCD)). We suggest a formula for the combined sensitivity to α and Xq that exhibits the dependence on proton number Z and mass number A, potentially allowing quantum electrodynamic (QED) and QCD effects to be disentangled if a broader range of isotopic abundance data becomes available. }, number={04}, journal={International Journal of Modern Physics E}, publisher={World Scientific Pub Co Pte Lt}, author={Davis, E. D. and Gould, C. R. and Sharapov, E. I.}, year={2014}, month={Apr}, pages={1430007} }
 @article{davis_zaher_2014, title={Time-dependent generalization of the Nosé-Hoover thermostatting technique for molecular dynamics simulations}, volume={490}, ISSN={1742-6596}, url={http://dx.doi.org/10.1088/1742-6596/490/1/012101}, DOI={10.1088/1742-6596/490/1/012101}, abstractNote={The Nosé-Hoover scheme demonstrates that molecular dynamics simulations can be used to calculate the properties of systems at constant temperature (i.e. canonical ensemble averages). There is interest in deterministic generalizations of Nosé-Hoover dynamics which are ergodic even for simple systems like the harmonic oscillator. Prompted by parallels with studies of the Duffing oscillator within control theory, we have investigated a non-autonomous version of the Nosé-Hoover oscillator in which the temperature is replaced by a weakly time-dependent function. This function is chosen so that its average over time coincides with the temperature desired. Calculations are facilitated by graphical programming with a MATLAB-Simulink platform. A time series analysis of our simple non-autonomous system yields the position and momentum distributions expected for the harmonic oscillator.}, journal={Journal of Physics: Conference Series}, publisher={IOP Publishing}, author={Davis, Edward D and Zaher, Ashraf A}, year={2014}, month={Mar}, pages={012101} }
 @article{davis_2011, title={Orbits of the Kepler problem via polar reciprocals}, volume={79}, ISSN={0002-9505 1943-2909}, url={http://dx.doi.org/10.1119/1.3639130}, DOI={10.1119/1.3639130}, abstractNote={Polar reciprocals of trajectories are an elegant alternative to hodographs for motion in a central force field. Their principal advantage is that the transformation from a trajectory to its polar reciprocal is its own inverse. The form of the polar reciprocals of Kepler orbits is established, and a geometrical construction is presented for the orbits of the Kepler problem starting from their polar reciprocals. No obscure knowledge of conics is required to demonstrate the validity of the method. Unlike a graphical procedure suggested by Feynman and extended by Derbes, the method based on polar reciprocals works without changes for elliptical, parabolic, and hyperbolic trajectories.}, number={12}, journal={American Journal of Physics}, publisher={American Association of Physics Teachers (AAPT)}, author={Davis, E. D.}, year={2011}, month={Dec}, pages={1246–1249} }
 @article{davis_gould_mitchell_sharapov_2005, title={Bounds on time reversal violation from polarized neutron capture with unpolarized targets}, volume={110}, ISSN={1044-677X}, url={http://dx.doi.org/10.6028/jres.110.075}, DOI={10.6028/jres.110.075}, abstractNote={We have analyzed constraints on parity-odd time-reversal noninvariant interactions derived from measurements of the energy dependence of parity-violating polarized neutron capture on unpolarized targets. As previous authors found, a perturbation in energy dependence due to a parity (P)-odd time (T)-odd interaction is present. However, the perturbation competes with T-even terms which can obscure the T-odd signature. We estimate the magnitudes of these competing terms and suggest strategies for a practicable experiment.}, number={4}, journal={Journal of Research of the National Institute of Standards and Technology}, publisher={National Institute of Standards and Technology (NIST)}, author={Davis, E.D. and Gould, C.R. and Mitchell, G.E. and Sharapov, E.I.}, year={2005}, month={Jul}, pages={485} }
 @article{davis_gould_mitchell_sharapov_2004, title={Bounds on P-odd T-odd interactions from polarized neutron capture with unpolarized targets}, volume={69}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.69.015501}, DOI={10.1103/physrevc.69.015501}, abstractNote={We expand on an interesting proposal (by Flambaum and Sushkov) to constrain parity-odd time-reversal noninvariant interactions with measurements of the energy dependence of parity-violating polarized neutron capture on unpolarized targets. We show that the perturbation in energy dependence due a P-odd T-odd interaction is obscured by terms due to electroweak effects. We evaluate for a practicable experiment the influence of these terms on the locations of zeros in a parity-violating asymmetry. Measurements which succeed in putting limits on these shifts of slightly more than the 1 meV or so that we estimate them to be, would constrain the ratio of the rms value of compound nucleus matrix elements of any P-odd T-odd nucleonnucleon interaction to the rms value of compound nucleus matrix elements of the P-odd nucleon-nucleon interaction to be less than of order of 10 ˛2 .}, number={1}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, E. D. and Gould, C. R. and Mitchell, G. E. and Sharapov, E. I.}, year={2004}, month={Jan} }
 @article{davis_2004, title={Uniform approximation of wave functions with improved semiclassical transformation amplitudes and Gram-Schmidt orthogonalization}, volume={70}, ISSN={1050-2947 1094-1622}, url={http://dx.doi.org/10.1103/physreva.70.032101}, DOI={10.1103/physreva.70.032101}, abstractNote={Semiclassical transformation theory implies an integral representation for stationary-state wave functions {psi}{sub m}(q) in terms of angle-action variables ({theta},J). It is a particular solution of Schroedinger's time-independent equation when terms of order ({Dirac_h}/2{pi}){sup 2} and higher are omitted, but the preexponential factor A(q,{theta}) in the integrand of this integral representation does not possess the correct dependence on q. The origin of the problem is identified: the standard unitarity condition invoked in semiclassical transformation theory does not fix adequately in A(q,{theta}) a factor which is a function of the action J written in terms of q and {theta}. A prescription for an improved choice of this factor, based on successfully reproducing the leading behavior of wave functions in the vicinity of potential minima, is outlined. Exact evaluation of the modified integral representation via the residue theorem is possible. It yields wave functions which are not, in general, orthogonal. However, closed-form results obtained after Gram-Schmidt orthogonalization bear a striking resemblance to the exact analytical expressions for the stationary-state wave functions of the various potential models considered (namely, a Poeschl-Teller oscillator and the Morse oscillator)}, number={3}, journal={Physical Review A}, publisher={American Physical Society (APS)}, author={Davis, Edward D.}, year={2004}, month={Sep} }
 @article{davis_ghandour_2003, title={On the use of angle-action variables in semiclassical mechanics}, volume={309}, ISSN={0375-9601}, url={http://dx.doi.org/10.1016/s0375-9601(03)00174-9}, DOI={10.1016/s0375-9601(03)00174-9}, abstractNote={We discuss a novel uniform semiclassical approximation for the bound state wave functions of simple conservative systems (of one degree of freedom) which sheds light on the success of semiclassical transformation theory in dealing with angle-action variables.}, number={1-2}, journal={Physics Letters A}, publisher={Elsevier BV}, author={Davis, Edward D. and Ghandour, Ghassan I.}, year={2003}, month={Mar}, pages={1–4} }
 @article{davis_ghandour_2002, title={Canonical transformations and non-unitary evolution}, volume={35}, ISSN={0305-4470}, url={http://dx.doi.org/10.1088/0305-4470/35/28/307}, DOI={10.1088/0305-4470/35/28/307}, abstractNote={We test the idea that transformations which, at the classical level, can be interpreted as evolutions are represented within quantum mechanics by unitary operators. To this end, we consider non-trivial canonical transformations which leave invariant the form of the Hamilton function of a system. We demonstrate that infinite families of such transformations exist for a variety of familiar conservative systems of one degree of freedom. We show how the precise form of integral equations for the stationary state wavefunctions implied by the existence of these canonical transformations can be pinned down by exploiting the algebra of the transformations and a symmetry of their generating functions. We recover several integral equations found in the literature on standard special functions of mathematical physics. We find that when one of the classical canonical transformations we consider is non-linear, its quantum implementation is non-unitary. We end with some comments on the implications of our findings for semiclassical studies and a brief discussion relevant to string theory of the generalization to scalar field theories in 1 + 1 dimensions.}, number={28}, journal={Journal of Physics A: Mathematical and General}, publisher={IOP Publishing}, author={Davis, E D and Ghandour, G I}, year={2002}, month={Jul}, pages={5875–5891} }
 @article{davis_ghandour_2001, title={On the ubiquity of non-unitary quantum canonical transformations}, volume={278}, ISSN={0375-9601}, url={http://dx.doi.org/10.1016/s0375-9601(00)00785-4}, DOI={10.1016/s0375-9601(00)00785-4}, abstractNote={We present examples in support of the conjecture that quantum canonical transformations which are used to establish the equivalence or duality of different quantum systems and which have non-linear classical counterparts will be non-unitary or, more generally, linear isomorphisms but not isometries.}, number={5}, journal={Physics Letters A}, publisher={Elsevier BV}, author={Davis, E.D. and Ghandour, G.I.}, year={2001}, month={Jan}, pages={239–242} }
 @article{davis_gould_1999, title={Extraction of bounds on time-reversal non-invariance from neutron reactions}, volume={447}, ISSN={0370-2693}, url={http://dx.doi.org/10.1016/s0370-2693(99)00013-1}, DOI={10.1016/s0370-2693(99)00013-1}, abstractNote={Ratios involving on-resonance measurements of the three-fold and five-fold correlation cross sections for which the dependence on some of the unknown spectroscopic data is eliminated are considered. Closed form expressions are derived for the statistical distributions of these ratios. Implications for bounds on the variance of matrix elements of time reversal non-invariant nucleon-nucleon interactions are considered within a Bayesian framework and the competitiveness with bounds from other experiments is evaluated. The prospects for null five-fold correlation measurements improving by an order of magnitude or more upon the current bound on a parity-conserving T-odd interaction are good.}, number={3-4}, journal={Physics Letters B}, publisher={Elsevier BV}, author={Davis, E.D. and Gould, C.R.}, year={1999}, month={Feb}, pages={209–215} }
 @article{davis_barrett_diallo_1999, title={Importance of the hexadecapole-hexadecapole interaction}, volume={59}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.59.200}, DOI={10.1103/physrevc.59.200}, abstractNote={Motivated by the sensitivity of collective $M1$ excitations to the hexadecapole-hexadecapole interaction, we explore the influence of this and other features of sdgIBM on the ground-state band properties of deformed rare-earth nuclei. We adopt microscopically motivated choices of the Hamiltonian parameters and work within the angular-momentum-projected intrinsic state formalism, deriving analytic expressions for observables in which the dependence on wave functions and parameters of the model is explicit. We find that energies of ground-state band excitations are insensitive to the hexadecapole-hexadecapole interaction. On the other hand, its contribution to the deformation energy term in the nuclear binding energy is substantial. Our results indicate that angular momentum projection is important even for well-deformed nuclei and that at least two g bosons should be utilized in the corresponding sdgIBM calculations.}, number={1}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, E. D. and Barrett, B. R. and Diallo, A. F.}, year={1999}, month={Jan}, pages={200–209} }
 @article{davis_gould_1998, title={On-resonance deformation effect measurements: A probe of order within chaos in the nucleus}, volume={57}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.57.648}, DOI={10.1103/physrevc.57.648}, abstractNote={The statistics of on-resonance measurements of the deformation effect cross section {sigma}{sub 02} in unpolarized neutron transmission through an aligned {sup 165}Ho target is discussed. Under the standard Porter-Thomas assumption about reduced partial width amplitudes, the sign of {sigma}{sub 02} is random at s-wave resonances with d-wave admixtures. Motivated by the observation of sign correlations in epithermal parity-violation studies, conditions under which a doorway state will give rise to {sigma}{sub 02}{close_quote}s of nonrandom sign are identified. Oblate shape isomers lying at excitation energies in the isolated resonance regime could meet these conditions. {copyright} {ital 1998} {ital The American Physical Society}}, number={2}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, E. D. and Gould, C. R.}, year={1998}, month={Feb}, pages={648–654} }
 @article{davis_1996, title={Self-consistent Bayesian analysis of space-time symmetry studies}, volume={370}, ISSN={0168-9002}, url={http://dx.doi.org/10.1016/0168-9002(95)00802-0}, DOI={10.1016/0168-9002(95)00802-0}, abstractNote={We introduce a Bayesian method for the analysis of epithermal neutron transmission data on space-time symmetries in which unique assignment of the prior is achieved by maximisation of the cross entropy and the imposition of a self-consistency criterion. Unlike the maximum likelihood method used in previous analyses of parity-violation data, our method is freed of an ad hoc cutoff parameter. Monte Carlo studies indicate that our self-consistent Bayesian analysis is superior to the maximum likelihood method when applied to the small data samples typical of symmetry studies.}, number={2-3}, journal={Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, publisher={Elsevier BV}, author={Davis, E.D.}, year={1996}, month={Feb}, pages={509–515} }
 @article{davis_diallo_barrett_1996, title={gboson and systematics of theM1 scissors mode}, volume={53}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.53.2849}, DOI={10.1103/physrevc.53.2849}, abstractNote={We discuss systematics of the {ital M}1 scissors mode within the interacting boson model when the {ital g}-boson degree of freedom is included explicitly and microscopically motivated choices of model parameters are adopted. We try to relate the {ital M}1 centroid energy to the energetics of deformation. We conclude that, with the introduction of a hexadecapole-hexadecapole interaction and a {ital g}-boson admixture in the ground state of only a few percent, we can obtain reasonable estimates of the {ital M}1 centroid energy, without invoking a Majorana interaction. If one takes seriously variations in microscopic estimates of boson {ital g} factors, then the summed {ital M}1 strength near midshell can be interpreted in terms of boson occupation numbers which saturate. {copyright} {ital 1996 The American Physical Society.}}, number={6}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, E. D. and Diallo, A. F. and Barrett, B. R.}, year={1996}, month={Jun}, pages={2849–2854} }
 @article{barrett_davis_diallo_1994, title={Can we do without the Majorana term in the effective nuclear interaction?}, volume={50}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.50.1917}, DOI={10.1103/physrevc.50.1917}, abstractNote={We present phenomenological evidence that the strength of the Majorana term necessary to reproduce collective [ital M] 1-transition strength data could be significantly smaller than is conventionally assumed and therefore more in line with naive microscopic considerations. We also find that [ital g]-boson effects are important to the reproduction of the summed [ital M]1 strength.}, number={4}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Barrett, B. R. and Davis, E. D. and Diallo, A. F.}, year={1994}, month={Oct}, pages={1917–1923} }
 @article{davis_1994, title={Constraint on time-reversal tests in fully chaotic nuclear systems}, volume={50}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.50.2236}, DOI={10.1103/physrevc.50.2236}, abstractNote={In tests exploiting the unique sensitivity of a fully chaotic system like the compound nucleus, the possibility exists that unknown resonance parameters and interaction matrix elements taken on values which preclude the observation of a violation of time-reversal invariance independent of the strength of the time-reversal noninvariant interaction. A nontrivial constraint on time-reversal tests is implied, namely, that the observable has to be sampled a minimum number of times [ital M][sub min] where [ital M][sub min][gt]3. Several experiments purporting to be tests of time reversal do not satisfy this condition.}, number={4}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, E. D.}, year={1994}, month={Oct}, pages={2236–2239} }
 @article{davis_navrátil_1994, title={Towards a satisfactory microscopic description of21+g factors}, volume={50}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.50.2362}, DOI={10.1103/physrevc.50.2362}, abstractNote={We investigate the possibility that microscopic boson [ital g] factor estimates may require revision and consider the impact on 2[sub 1][sup +] [ital g] factors of the difference [epsilon][sub [ital v]] between the neutron and proton [ital d] boson energies found typically in microscopic evaluations of interacting boson model parameters. We recalculate microscopic estimates for both [ital d] and [ital g] boson [ital g] factors, this time using the similarity-transformed Dyson boson mapping approach. Modulo more pronounced variation at the beginning and end of shells, our results confirm previous estimates by other methods. Differences between [ital d] and [ital g] boson factors are too small for the inclusion of [ital g] bosons to have a significant effect on 2[sub 1][sup +] [ital g] factor predictions. Instead, we present qualitative and semiquantitative arguments in support of the contention that [ital microscopic] estimates of [epsilon][sub [ital v]] (taken in conjunction with our microscopic boson [ital g] factors) can, by and large, account for the systematics of 2[sub 1][sup +] [ital g] factors in the [ital Z]=50-to-82 and [ital N]=82-to-126 shells. Detailed calculations for [sup 148]Sm and [sup 154]Sm are consistent with this assertion provided the Majorana interaction strength [xi][sub 2] is negligible. more » Our detailed calculations suggest substantial [ital F]-spin admixtures in the 2[sub 1][sup +] states of [sup 148]Sm (at the 20% level or more) and the members of ground-state band of [sup 154]Sm (9% or so), and point to the existence of a mixed-symmetric [beta] bandhead in [sup 154]Sm at below 2 MeV. « less}, number={5}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, E. D. and Navrátil, P.}, year={1994}, month={Nov}, pages={2362–2371} }
 @article{diallo_davis_barrett_1993, title={An Improved Asymptotic Realization of the Projected Intrinsic State Approximation in IBM}, volume={222}, ISSN={0003-4916}, url={http://dx.doi.org/10.1006/aphy.1993.1020}, DOI={10.1006/aphy.1993.1020}, abstractNote={The authors clarify the character of the semi-analytic 1/N-expansion method utilised in otherwise clumbersome studies with the sdg-variant of the interacting boson model. They draw attention to the dynamical foundations of the scheme. It is argued that, by respecting the conditions under which use of the asymptotic expansions involved is legitimate, it may be learned whether the dynamical assumptions made are appropriate or not. To this end, it is shown that an ad hoc [open quotes]gaussian[close quotes] approximation of previous applications can be avoided without any sacrifice of simplicity. The new asymptotic expansion of the fundamental overlap integral differs in every order beyond leading-order. Nevertheless, it is confirmed that, to the order of practical interest, the all-important variational functional for the groundstate-band coincides with that employed previously; the demonstration makes explicit the cancellation mechanism. To illustrate the practical advantages of the new scheme, the authors derive an expression for the gyromagnetic factors of the groundstate-band: it is freed of the deficiencies of the former 1/N-expansion method result. In general, claims that strong variations in an observable unaccounted for by the leading term can be described by higher-order terms are necessarily suspect. 11 refs.}, number={2}, journal={Annals of Physics}, publisher={Elsevier BV}, author={Diallo, A.F. and Davis, E.D. and Barrett, B.R.}, year={1993}, month={Mar}, pages={159–186} }
 @article{białynicki-birula_davis_rafelski_1993, title={Evolution modes of the vacuum Wigner function in strong-field QED}, volume={311}, ISSN={0370-2693}, url={http://dx.doi.org/10.1016/0370-2693(93)90578-6}, DOI={10.1016/0370-2693(93)90578-6}, abstractNote={The physical content of a non-covariant quantum-field theoretic transport formalism for strong-field QED is addressed within an integral formulation of the evolution equations which highlights the relation to acoustic and Zitterbewegung modes of the field-free limit. Through the computation within this framework of the electric susceptibility of the vacuum at the one-loop level, it is established that the off-shell behaviour of the electron-positron field is correctly incorporated. The Zitterbewegung mode is seen to be solely responsible at the one-loop level for vacuum polarization. Implications for the full renormalisation of the theory are taken up.}, number={1-4}, journal={Physics Letters B}, publisher={Elsevier BV}, author={Białynicki-Birula, I. and Davis, E.D. and Rafelski, J.}, year={1993}, month={Jul}, pages={329–338} }
 @article{koster_davis_gould_haase_roberson_seagondollar_1992, title={Test of time reversal invariance in 2-MeV neutron scattering from aligned165Ho}, volume={75}, ISSN={0304-3843 1572-9540}, url={http://dx.doi.org/10.1007/bf02398973}, DOI={10.1007/bf02398973}, number={1-4}, journal={Hyperfine Interactions}, publisher={Springer Science and Business Media LLC}, author={Koster, J. E. and Davis, E. D. and Gould, C. R. and Haase, D. G. and Roberson, N. R. and Seagondollar, L. W.}, year={1992}, month={Nov}, pages={165–172} }
 @article{barrett_davis_diallo_1992, title={g-boson panacea for magnetic properties of the nuclear groundstate band?}, volume={295}, ISSN={0370-2693}, url={http://dx.doi.org/10.1016/0370-2693(92)90079-j}, DOI={10.1016/0370-2693(92)90079-j}, abstractNote={The magnetic moments of excited members of the groundstate band of even-even medium-mass nuclei are considered within the framework of the sdg-version of IBM-2. A novel asymptotic realisation of the variation-after-(angular-momentum)-projection Hartree-Bose approximation is employed. The introduction of an explicit g-boson degree of freedom is found not to resolve the discrepancy between the values of the d-boson g-factors required phenomenologically and those expected microscopically. Further study of the microscopic underpinning of the g-boson and improved experimental data are required to clarify matters: a promising testing ground would appear to be the Hf-Pt nuclei. Neither the present asymptotic realisation nor its predecessor (the “1/N-scheme”) are appropriate when strong variations of magnetic moments within a groundstate band are encountered.}, number={1-2}, journal={Physics Letters B}, publisher={Elsevier BV}, author={Barrett, B.R. and Davis, E.D. and Diallo, A.F.}, year={1992}, month={Nov}, pages={5–10} }
 @article{koster_davis_gould_haase_roberson_seagondollar_wilburn_zhu_1991, title={Direct reaction test of T violation in 2 MeV neutron scattering from aligned 165Ho}, volume={267}, ISSN={0370-2693}, url={http://dx.doi.org/10.1016/0370-2693(91)90517-t}, DOI={10.1016/0370-2693(91)90517-t}, abstractNote={The parity-even time-reversal-odd five-fold correlation has been studied in 2 MeV polarized neutron transmission through a rotating, cryogenically-aligned 165Ho target. The analyzing power was found to be (1 ± 6) × 10−4, consistent with time reversal invariance. We obtain a bound of 5 × 10−3 for αT, the ratio of T-odd to T-even couplings in the effective N−N interaction.}, number={1}, journal={Physics Letters B}, publisher={Elsevier BV}, author={Koster, J.E. and Davis, E.D. and Gould, C.R. and Haase, D.G. and Roberson, N.R. and Seagondollar, L.W. and Wilburn, S. and Zhu, X.}, year={1991}, month={Sep}, pages={23–26} }
 @article{davis_1991, title={Nuclear parity violation beyond the two-state approximation: Criteria for quantitative studies above neutron threshold}, volume={340}, ISSN={0939-7922 1434-601X}, url={http://dx.doi.org/10.1007/bf01303827}, DOI={10.1007/bf01303827}, number={2}, journal={Zeitschrift f�r Physik A Hadrons and Nuclei}, publisher={Springer Science and Business Media LLC}, author={Davis, E. D.}, year={1991}, month={Jun}, pages={159–163} }
 @article{davis_hartmann_1991, title={Nuclear sensitivity to time-reversal non-invariance: Traditional detailed balance}, volume={211}, ISSN={0003-4916}, url={http://dx.doi.org/10.1016/0003-4916(91)90209-q}, DOI={10.1016/0003-4916(91)90209-q}, abstractNote={We investigate the most basic fluctuation measure relevant to traditional detailed balance studies with compound nucleus reactions. The treatment is exact to leading order in the hypothetical parity-even time-reversal-odd part of the nuclear interaction and applies from the regime of isolated resonances through to that of strongly-overlapping resonances. We infer approximate expressions in which the scaling with basic compound nucleus parameters is manifest and identify the presence of two enhancements: admixture and lifetime. We confirm the validity of assumptions implicit in the previous theoretical treatment of the strongly-overlapping regime. For the purpose of order of magnitude estimates, this treatment is adequate throughout the overlapping resonance regime. We find that, in the resolved resonance regime, the correlations due to unitarity between the symmetric and anti-symmetric parts of the S-matrix are strong. With regard to future measurements, we present a revised sensitivity estimate for the class of optimal isolated-resonance regime measurements identified recently and we argue in favour of two observables constructed entirely from energy averages (which have some practical advantages). We conclude that, for the case of (p, α0)(α, p0)-reactions, one of our observables constructed from energy averages is only marginally less sensitive than optimal isolated-resonance regime measurements. Related findings are that: conventional measurements with (p, α0)(α, p0)-reactions in the overlapping resonance regime of medium-weight nuclei (A ∼ 100) can possess a sensitivity comparable to that of optimal isolated-resonance regime measurements; on-resonance measurements in the isolated resonance regime are of interest in as much as they benefit from dynamic and structural enhancement.}, number={2}, journal={Annals of Physics}, publisher={Elsevier BV}, author={Davis, E.D and Hartmann, U}, year={1991}, month={Nov}, pages={334–386} }
 @article{davis_diallo_barrett_balantekin_1991, title={Particle-hole symmetry,F-spin, andr-process parameters}, volume={44}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.44.1655}, DOI={10.1103/physrevc.44.1655}, abstractNote={We exploit approximate symmetry under particle-hole conjugation and the systematics associated with a classification scheme (inspired by the neutron-proton interacting boson model) to obtain estimates of binding energies and low-lying excitation energies for even-even {ital r}-process nuclei drawn from the major proton and neutron shells, 50{lt}{ital Z}{lt}82 and 82{lt}{ital N}{lt}126. We anticipate that our simple formalism for binding energies, depending on only six parameters, has an accuracy of {similar to}0.8 MeV. We argue that the particular dual particle-hole conjugation symmetry required to relate excitation energies in neutron-rich nuclei to the known excitation energies of the corresponding conjugated nuclei holds to within 10% or so.}, number={4}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Davis, E. D. and Diallo, A. F. and Barrett, B. R. and Balantekin, A. B.}, year={1991}, month={Oct}, pages={1655–1660} }
 @article{müller_davis_harney_1990, title={Parity violation in compound-nucleus reactions}, volume={65}, ISSN={0031-9007}, url={http://dx.doi.org/10.1103/physrevlett.65.1329}, DOI={10.1103/physrevlett.65.1329}, abstractNote={A formalism is developed that incorporates parity violation into the statistical theory of nuclear reactions. It allows the calculation of average square values of observables sensitive to parity breaking starting from well known average parameters (transmission coefficients and level densities) as input. For the case of low-energy neutron resonance scattering, a systematic study of the expected size of the effect is presented. An enhanced sensitivity of these reactions to parity violation is borne out.}, number={11}, journal={Physical Review Letters}, publisher={American Physical Society (APS)}, author={Müller, A. and Davis, E. and Harney, H.}, year={1990}, month={Sep}, pages={1329–1331} }
 @article{bunakov_davis_weidenmüller_1990, title={Tests of fundamental symmetries on isolated compound-nucleus resonances}, volume={42}, ISSN={0556-2813 1089-490X}, url={http://dx.doi.org/10.1103/physrevc.42.1718}, DOI={10.1103/physrevc.42.1718}, abstractNote={Previous theoretical work has shown that parity and time-reversal symmetry can be tested with particularly high sensitivity in the domain of isolated compound-nucleus resonances. In this domain, experiments will naturally focus on individual resonances rather than on the background cross section. The theoretical analysis of this situation leads to the concept of an ensemble of ``on-resonance'' measurements. This concept naturally emerges by combining two previous theoretical approaches to tests of fundamental symmetries. We investigate the properties of this new ensemble and show how to convert ``on-resonance'' data into statistically significant information on symmetry violation.}, number={4}, journal={Physical Review C}, publisher={American Physical Society (APS)}, author={Bunakov, V. E. and Davis, E. D. and Weidenmüller, H. A.}, year={1990}, month={Oct}, pages={1718–1730} }
 @article{davis_boos�_1989, title={Higher moments of the fluctuatingS-matrix within the stochastic model for compound-nucleus scattering}, volume={332}, ISSN={0930-1151 1434-601X}, url={http://dx.doi.org/10.1007/bf01292429}, DOI={10.1007/bf01292429}, abstractNote={We present expressions for the energy-averages of the most general products of fluctuatingS-matrix elements required to calculate the variance in the energy-averaged cross-section and related observables for compound-nucleus processes. The results, which areexact and hold from the regime of isolated resonances through to that of strongly-overlapping resonances (independently of the number of open channels), involve no more than straightforward three-dimensional integrals. In line with earlier general arguments, they are functions only of averageS-matrix elements. Explicit (asymptotic) expansions which approximate these results in the domain of strongly-overlapping resonances are also determined and the leading order corrections to Ericson's treatment of fluctuations deduced. Contrary to previous studies, we find that the fluctuatingS-matrix is not necessarily Gaussian distributed in this regime. In addition, we demonstrate how unitarity can be used to check our results both numerically and analytically. Other technical issues addressed include the casting of the generating function used into an “optimal” form, the treatment of complications due to its non-trivial dependence on the source matrix, and identities for the extraction of the maximal order term. These lay a foundation for other applications of the stochastic model for compound-nucleus processes.}, number={4}, journal={Zeitschrift f�r Physik A Atomic Nuclei}, publisher={Springer Science and Business Media LLC}, author={Davis, E. D. and Boos�, D.}, year={1989}, month={Dec}, pages={427–441} }
 @article{davis_1989, title={Systematic nuclear sensitivity to time reversal noninvariance}, volume={226}, ISSN={0370-2693}, url={http://dx.doi.org/10.1016/0370-2693(89)91179-9}, DOI={10.1016/0370-2693(89)91179-9}, abstractNote={I argue in favour of using, for resolved resonances (PR), energy averages of observables in compound-nucleus (CN) reactions to set bounds on the strength of a parity- (P-) even time-reversal- (T-) odd nucleon-nucleon interaction. I show that an observable of this type exists, which, if measured to the accuracy of previous detailed-balance studies, could be used to lower the bound by an order of magnitude.}, number={3-4}, journal={Physics Letters B}, publisher={Elsevier BV}, author={Davis, E.D.}, year={1989}, month={Aug}, pages={197–201} }
 @article{hartmann_davis_1989, title={epic Grass - symbolic calculations with anticommuting variables}, volume={54}, ISSN={0010-4655}, url={http://dx.doi.org/10.1016/0010-4655(89)90096-9}, DOI={10.1016/0010-4655(89)90096-9}, abstractNote={epicGrass is a specialised symbolic manipulation utility for handling complicated (matrix) expressions involving commuting and anticommuting (Grassmann) variables. Its chief strength is its speed, achieved by “hardwiring” the Grassmann algebra using a table. User-friendly features include: a number of built-in functions to simplify the manipulation of matrices and expressions, an on-line help facility, sophisticated error messages and several output formats. The program has been extensively tested and a complete record of these tests is available. Extension to other related algebraic structures arising in theoretical physics is straightforward.}, number={2-3}, journal={Computer Physics Communications}, publisher={Elsevier BV}, author={Hartmann, U. and Davis, E.D.}, year={1989}, month={Jun}, pages={353–369} }
 @article{davis_boosé_1988, title={On the variance of the fluctuating cross section}, volume={211}, ISSN={0370-2693}, url={http://dx.doi.org/10.1016/0370-2693(88)91879-5}, DOI={10.1016/0370-2693(88)91879-5}, abstractNote={We present an exact expression for the variance in the average cross section of a compound-nucleus reaction between two definite channels and explore its qualitative features. In particular, we discuss deviations from Ericson theory and their relevance to searches for time-reversal non-invariance in compound-nucleus reactions.}, number={4}, journal={Physics Letters B}, publisher={Elsevier BV}, author={Davis, E.D. and Boosé, D.}, year={1988}, month={Sep}, pages={379–383} }
 @article{davis_miller_1987, title={“Phase transitions” at finite temperature in finite systems}, volume={196}, ISSN={0370-2693}, url={http://dx.doi.org/10.1016/0370-2693(87)90730-1}, DOI={10.1016/0370-2693(87)90730-1}, abstractNote={Indications of phase transitions (present in the thermodynamic limit) are seen in the solution for a finite number of particles of an exactly solvable model. The gross structure of the implied exact “phase diagram” is reproduced by self-consistent mean-field approximations, but not, in general, the precise location of the “phase” boundaries.}, number={3}, journal={Physics Letters B}, publisher={Elsevier BV}, author={Davis, E.D. and Miller, H.G.}, year={1987}, month={Oct}, pages={277–280} }
 @article{davis_heiss_1986, title={Random-phase approximation and broken symmetry}, volume={12}, ISSN={0305-4616}, url={http://dx.doi.org/10.1088/0305-4616/12/9/006}, DOI={10.1088/0305-4616/12/9/006}, abstractNote={The validity of the random-phase approximation (RPA) in broken-symmetry bases is tested in an appropriate many-body system for which exact solutions are available. Initially the regions of stability of the self-consistent quasiparticle bases in this system are established and depicted in a 'phase' diagram. It is found that only stable bases can be used in an RPA calculation. This is particularly true for those RPA modes which are not associated with the onset of instability of the basis; the authors see that these modes do not describe any excited state when the basis is unstable, although from a formal point of view they remain acceptable. The RPA does well in a stable broken-symmetry basis provided one is not too close to a point where a phase transition occurs. This is true for both energies and matrix elements.}, number={9}, journal={Journal of Physics G: Nuclear Physics}, publisher={IOP Publishing}, author={Davis, E D and Heiss, W D}, year={1986}, month={Sep}, pages={805–820} }
 @article{davis_heiss_1984, title={Convergence of a crossing‐symmetric perturbation series for the four‐point vertex}, volume={25}, ISSN={0022-2488 1089-7658}, url={http://dx.doi.org/10.1063/1.526227}, DOI={10.1063/1.526227}, abstractNote={A finite radius of convergence is established for a perturbation expansion of the crossing-symmetric vertex function in a discrete model.}, number={4}, journal={Journal of Mathematical Physics}, publisher={AIP Publishing}, author={Davis, E. D. and Heiss, W. D.}, year={1984}, month={Apr}, pages={812–813} }