Nuclear Force

An inspection game is a mathematical model of a situation in which an inspector verifies the adherence of an inspectee to some legal obligation, such as an arms control treaty, where the inspectee may have an interest in violating that obligation. The mathematical analysis ...

We consider various forms of the mass term that can be used in the Skyrme model and their implications on the properties of baryonic states. We show that, with an appropriate choice for the mass term, without changing the asymptotic behaviour of the profile functions at large r, we can considerably reduce or increase the mass term’s contribution to the classical mass of the solitons. We find that multibaryon configurations can be classically bound at large baryon numbers for some choices of this mass term. 1

The Similarity Renormalization Group (SRG) is a continuous series of unitary transformations that can be implemented as a flow equation. When the relative kinetic energy (T rel) is used in the SRG generator, nuclear structure calculations have shown greatly improved convergence with basis size because of the decoupling of high-energy and low-energy physics. However this generator can sometimes be problematic. A test case is provided by a study of initial interactions from chiral effective field theories with large cutoffs, which can lead to spurious deep bound states. We would like the SRG to decouple these from the physical shallow bound states. However, with T rel the high-and low-energy bound states are not decoupled in the usual sense. Replacing T rel by the momentum-space diagonal of the Hamiltonian (H d) in the SRG generator does produce decoupling, such that the shallow states are in the low-momentum region and the deep bound states are at higher momentum. The flow toward universal low-momentum interactions is also restored.

A formula, generating the Spinning Magnetic Field (SMF) has been derived, the interaction of two SMF by two protons, using the recently derived unified formula of fields, produced Spinning Magnetic Force (SMFs); while at each step, the mutual electrostatic force by both protons is subtracted from the relevant Spinning Magnetic Force (SMFs), this resulted in the nuclear strong force; this paper is a modified version of previous SMFs, it established and replicated the nuclear force as computed from potential graph; while the Weak Spinning Magnetic Force (F_W) which is the reverse of the Spinning Magnetic Force (SMFs), is produced as a result of an internal repulsive force caused by an agitation of two SMF, forming spiral rotation inside neutron leading to an internal instability, ended by the disconnection of both the electron and the proton; the knowledge of this mechanism will help in understanding both phenomena, and the production of the nuclear fusion, that may help to envision other forms of the most needed alternative renewable energy.

Precise measurements of deuteron vector and tensor analyzing powers A y d , A xx , A yy , and A xz in d-p elastic scattering were performed via 1 H(d ជ ,d)p and 1 H(d ជ ,p)d reactions at three incoming deuteron energies of E d lab ϭ140, 200, and 270 MeV. A wide range of center-of-mass angles from Ϸ10°to 180°was covered. The cross section was measured at 140 and 270 MeV at the same angles. These high precision data were compared with theoretical predictions based on exact solutions of three-nucleon Faddeev equations and modern nucleonnucleon potentials combined with three-nucleon forces. Three-body interactions representing a wide range of present day models have been used: the Tucson-Melbourne 2-exchange model, a modification thereof closer to chiral symmetry, the Urbana IX model, and a phenomenological spin-orbit ansatz. Large three-nucleon force effects are predicted, especially at the two higher energies. However, only some of them, predominantly d/d⍀ and A y d , are supported by the present data. For tensor analyzing powers the predicted effects are in drastic conflict to the data, indicating defects of the present day three-nucleon force models.

We discuss lattice simulations of light nuclei at leading order in chiral effective field theory. Using lattice pion fields and auxiliary fields, we include the physics of instantaneous one-pion exchange and the leading-order S-wave contact interactions. We also consider higher-derivative contact interactions which adjust the S-wave scattering amplitude at higher momenta. By construction our lattice path integral is positive definite in the limit of exact Wigner SU(4) symmetry for any even number of nucleons. This SU(4) positivity and the approximate SU(4) symmetry of the low-energy interactions play an important role in suppressing sign and phase oscillations in Monte Carlo simulations. We assess the computational scaling of the lattice algorithm for light nuclei with up to eight nucleons and analyze in detail calculations of the deuteron, triton, and helium-4.

We study the possibility of producing a new kind of nuclear systems which in addition to ordinary nucleons contain a few antibaryons (B = p, Λ, etc.). The properties of such systems are described within the relativistic mean-field model by employing G-parity transformed interactions for antibaryons. Calculations are first done for infinite systems and then for finite nuclei from 4 He to 208 Pb. It is demonstrated that the presence of a real antibaryon leads to a strong rearrangement of a target nucleus resulting in a significant increase of its binding energy and local compression. Noticeable effects remain even after the antibaryon coupling constants are reduced by factor 3 − 4 compared to G-parity motivated values. We have performed detailed calculations of the antibaryon annihilation rates in the nuclear environment by applying a kinetic approach. It is shown that due to significant reduction of the reaction Q-values, the in-medium annihilation rates should be strongly suppressed leading to relatively long-lived antibaryonnucleus systems. Multi-nucleon annihilation channels are analyzed too. We have also estimated formation probabilities of bound B + A systems in pA reactions and have found that their observation will be feasible at the future GSI antiproton facility. Several observable signatures are proposed. The possibility of producing multi-quark-antiquark clusters is discussed.

We are looking for a holographic explanation of nuclear forces, especially the attractive forces. Recently, the repulsive hard core of a nucleon-nucleon potential was obtained in the Sakai-Sugimoto model, and we show that a generalized version of that model-with an asymmetric configuration of the flavor D8 branes-also has an attractive potential. While the repulsive potential stems from the Chern-Simons interactions of the U(2) flavor gauge fields in 5D, the attractive potential is due to a coupling of the gauge fields to a scalar field describing fluctuations of the flavor branes' geometry. At intermediate distances r between baryons-smaller than R KK = O(1)/M ω meson but larger than the radius ρ ∼ R KK / √ λ′ t Hooft of the instanton at the core of a baryon-both the attractive and the repulsive potentials behave as 1/r 2 , but the attractive potential is weaker: Depending on the geometry of the flavor D8 branes, the ratio C a/r = −V attr (r)/V rep (r) ranges from 0 to 1 9. The 5D scalar fields also affect the isovector tensor and spin-spin forces, and the overall effect is similar to the isoscalar central forces, V (r) → (1 − C a/r) × V (r). At longer ranges r R KK , we find that the attractive potential decays faster than the repulsive potential, so the net potential is always repulsive. This unrealistic behavior may be peculiar to the Sakai-Sugimoto-like models, or it could be a general problem of the N c → ∞ limit inherent in holography.

Spin observables in proton deuteron breakup reactions at low energies offer a rich testing ground for the modern theory of nuclear forces, the chiral effective field theory (EFT). In the three-nucleon continuum the experimental data and the theoretical predictions are today at variance. At the PAX facility at COSY we plan to make an extensive study of analyzing powers and spin correlation parameters in pd breakup reactions at low energies between 30 and 50 MeV, an energy range where previous measurements are scarce and limited while three-nucleon effects are expected to be significant. Furthermore it is an ideal energy for the predictive power of chiral EFT to be tested. The longstanding physics question of the nature of three-nucleon forces will be studied with large coverage provided by an optimized silicon detector barrel, and flexibility utilizing the sampling method, a technique for direct comparison between experiment and theory developed specifically for the complex analysis of three-particle final states. The proposed experiment will yield an independent determination of the low-energy constants D and E and enable tests of appearing three-nucleon interactions in chiral EFT, with possible implications also for the spectra of light nuclei.

Observables in elastic proton-deuteron scattering are sensitive probes of the nucleon-nucleon interaction and three-nucleon force effects. The present experimental data base for this reaction is large, but contains a large discrepancy between data sets for the differential cross section taken at 135 MeV/nucleon by two experimental research groups. This paper reviews the background of this problem and presents new data taken at KVI. Differential cross sections and analyzing powers for the 2 H(p, d)p and H(d, d)p reactions at 135 MeV/nucleon and 65 MeV/nucleon, respectively, have been measured. The data differ significantly from previous measurements and consistently follow the energy dependence as expected from an interpolation of published data taken over a large range at intermediate energies.

High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (N N) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the ∆-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant N N and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear preference for the predictions in which the 3NF's are included. The majority of the experimental data points is well reproduced by the theoretical predictions. The remaining discrepancies are investigated by inspecting cross sections integrated over certain kinematical variables. The procedure of global comparisons leads to establishing regularities in disagreements between the experimental data and the theoretically predicted values of the cross sections. They indicate deficiencies still present in the assumed models of the 3N system dynamics.

Current calculations of nuclear shadowing for parton distributions are reviewed. The analysis of pA data is performed using exact QCD sum rules for the total momentum and baryon charge of nuclei. Evidence is found for an overall enhancement of GA in nuclei (> 4% for A >> 1). Combined with the calculation of nuclear shadowing at small z, our analysis indicates an enhancement of valence quark and gluon fields in nuclei for z N 0.1 of about 10 (20)% for A = 40 (A = co), as well as a suppression of the sea, at least for I < 0.1 and of valence quarks at z < 0.02. It is also pointed out that due to scaling violations the small shadowing observed in the Drell-Yan data

We prove that any bilinear coupling of a massive spin-3/2 field can be brought into a gauge invariant form suggested by Pascalutsa by means of a non-linear field redefinition. The corresponding field transformation is given explicitly in a closed form and the implications for chiral effective field theory with explicit ∆(1232) isobar degrees of freedom are discussed.

High precision vector and tensor analyzing power data of the deuteron-proton elastic scattering at 130 MeV deuteron beam energy have been measured in a large range of angles. They are compared with theoretical predictions obtained in various approaches: with realistic potentials for pure NN interactions, with the inclusion of a three-nucleon force, and in the framework of chiral perturbation theory. All the theoretical calculations describe roughly the main features of the measured distributions, but none of them can reproduce all their details. This indicates the need for further development of the three-nucleon force models.

High precision data for vector and tensor analyzing powers of the 1 H(d, pp)n breakup reaction at 130 and 100 MeV deuteron beam energies have been measured in a large fraction of the phase space. They are compared to the theoretical predictions based on various approaches to describe the three nucleon (3N) system dynamics. Theoretical predictions describe very well the vector analyzing power data, with no need to include any three-nucleon force effects for these observables. Tensor analyzing powers can be also very well reproduced by calculations in most of the studied region, but locally certain discrepancies are observed. At 130 MeV for A xy such discrepancies usually appear, or are enhanced, when model 3N forces are included. Predicted effects of 3NFs are much lower at 100 MeV and at this energy equally good consistency between the data and the calculations is obtained with or without 3NFs. Observables for three-nucleon (3N) systems constitute important basis for testing modern approaches to describe interactions between nucleons. The deuteron-nucleon breakup reaction leads to a final state with three free particles, thus providing possibility to study observables for continuous set of kinematical configurations

ABSTRACT Calculations of Levinson and Banerjee using the direct-interaction model for the inelastic scattering of protons indicated that the optical potential seen by the scattered particle is weaker than for the corresponding elastic scattering process. In this paper the scattering amplitude is derived and the “1/A-corrections” to it are examined. It is shown that these represent corrections to the optical potential and arise from the requirement that the contribution of a given target nucleon to the optical potential be removed when that nucleon is interacting directly with the incident particle. It is shown that the short range, symmetry-dependence and spin-dependence of nuclear forces can make this an important correction and can explain the Levinson-Banerjee reduction. It is also shown that the strength of the effective two-body interaction, or t-matrix, is in good agreement with the strength found by Levinson and Banerjee. The distorted-wave direct-interaction model is therefore capable of predicting the absolute magnitude of the inelastic cross section.

Nuclear forces are considered based on chiral perturbation theory with and without explicit ∆-isobar degrees of freedom. We discuss the subleading corrections to chiral three-nucleon forces in the ∆-less formalism which contain no additional free parameters. In the formalism with explicit ∆-isobar we present the complete next-to-next-to-leading order analysis of isospin-conserving and next-to-leading order analysis of isospinviolating nuclear forces. The perturbative expansion of nuclear forces in the ∆-full case is shown to have much better convergence compared with the ∆-less theory where the ∆-resonance is integrated out and is encoded in certain low-energy constants.

A tagged medium-energy neutron beam has been used in a precise measurement of the absolute differential cross section for np back-scattering. The results resolve significant discrepancies within the np database concerning the angular dependence in this regime. The experiment has determined the absolute normalization with ±1.5% uncertainty, suitable to verify constraints of supposedly comparable precision that arise from the rest of the database in partial wave analyses. The analysis procedures, especially those associated with the evaluation of systematic errors in the experiment, are described in detail so that systematic uncertainties may be included in a reasonable way in subsequent partial wave analysis fits incorporating the present results.

Cross sections were measured for the near-threshold electrodisintegration of 3 He at momentum transfer values of q = 2.4, 4.4, and 4.7 fm −1. From these and prior measurements the transverse and longitudinal response functions RT and RL were deduced. Comparisons are made against previously published and new non-relativistic A = 3 calculations using the best available NN potentials. In general, for q < 2 fm −1 these calculations accurately predict the threshold electrodisintegration of 3 He. Agreement at increasing q demands consideration of two-body terms, but discrepancies still appear at the highest momentum transfers probed, perhaps due to the neglect of relativistic dynamics, or to the underestimation of high-momentum wave-function components.

... Angular-momentum-dependent fission barriers in the rare-earth region F. Plasil, T. C. Awes, B. Cheynis, &#x27; D. Drain, &#x27; RL Ferguson, F. E. Obenshain, A. J. Sierk, SG Steadman, &#x27; and Q. R. Young ... Lett. 78B, 17 (1978). F. Plasil, RL Ferguson, RL Hahn, FE Obenshain, F. Pleason-...

Recent advances in ab initio quantum many-body methods and growth in computer power now enable highly precise calculations of nuclear structure. The precision has attained a level sufficient to make clear statements on the nature of 3-body forces in nuclear physics. Total binding energies, spin-dependent structure effects, and electroweak properties of light nuclei play major roles in pinpointing properties of the underlying strong interaction. Eventually, we anticipate a theory bridge with immense predictive power from QCD through nuclear forces to nuclear structure and nuclear reactions. Light front Hamiltonian quantum field theory offers an attractive pathway and we outline key elements.

In the modern description of nuclear forces based on chiral effective field theory, four-nucleon operators with unknown coupling constants appear. These couplings can be fixed by a fit to the low partial waves of neutron-proton scattering. We show that the so determined numerical values can be understood on the basis of phenomenological one-boson-exchange models. We also extract these values from various modern high accuracy nucleon-nucleon potentials and demonstrate their consistency and remarkable agreement with the values in the chiral effective field theory approach. This paves the way for estimating the low-energy constants of operators with more nucleon fields and/or external probes.

Multi-electron production is studied at high electron transverse momentum in positronand electron-proton collisions using the H1 detector at HERA. The data correspond to an integrated luminosity of 115 pb −1. Di-electron and tri-electron event yields are measured. Cross sections are derived in a restricted phase space region dominated by photon-photon collisions. In general good agreement is found with the Standard Model predictions. However, for electron pair invariant masses above 100 GeV, three di-electron events and three tri-electron events are observed, compared to Standard Model expectations of 0.30 ± 0.04 and 0.23 ± 0.04, respectively.

The chiral low-energy constants cD and cE are constrained by means of accurate ab initio calculations of the A = 3 binding energies and, for the first time, of the triton β decay. We demonstrate that these low-energy observables allow a robust determination of the two undetermined constants, a result of the surprising fact that the determination of cD depends weakly on the short range correlations in the wave functions. These two-plus three-nucleon interactions, originating in chiral effective field theory and constrained by properties of the A = 2 system and the present determination of cD and cE, are successful in predicting properties of the A = 3, and 4 systems. 21.45.Ff, The fundamental connection between nuclear forces and the underlying theory of quantum chromodynamics (QCD) remains one of the greatest contemporary theoretical challenges, due to the non-perturbative character of QCD in the low-energy regime relevant to nuclear phenomena. However, the last two decades of theoretical developments provide us with a bridge to overcome this obstacle, in the form of chiral perturbation theory (χPT) [1]. The χPT Lagrangian, constructed by integrating out degrees of freedom of the order of Λ χ ∼ 1 GeV and higher (nucleons and pions are thus the only explicit degrees of freedom), is an effective Lagrangian of QCD at low energies. As such, it retains all conjectured symmetry principles, particularly the approximate chiral symmetry, of the underlying theory. Furthermore, it can be organized in terms of a perturbative expansion in positive powers of Q/Λ χ where Q is the generic momentum in the nuclear process or the pion mass [1]. Though the subject of an ongoing debate about its validity [2, 3], the naive extension of this expansion to non-perturbative phenomena provides a practical interface with existing manybody techniques, and clearly holds a significant value for the study of the properties of QCD at low energy and its chiral symmetry.

We start from a low-energy effective field theory for interacting fermions on the lattice and expand in the hopping parameter to derive the nearest-neighbor interactions for a lattice gas model. In this model the renormalization of couplings for different lattice spacings is inherited from the effective field theory, systematic errors can be estimated a priori, and the breakdown of the lattice gas model description at low temperatures can be understood quantitatively. We apply the lattice gas method to neutron matter and compare with results from a recent quantum simulation.

We start from a low-energy effective field theory for interacting fermions on the lattice and expand in the hopping parameter to derive the nearest-neighbor interactions for a lattice gas model. In this model the renormalization of couplings for different lattice spacings is inherited from the effective field theory, systematic errors can be estimated a priori, and the breakdown

The differential cross sections and vector analyzing powers for nd elastic scattering at E n = 248 MeV were measured for 10°-180° in the center-of-mass (c.m.) system. To cover the wide angular range, the experiments were performed separately by using two different setups for forward and backward angles. The data are compared with theoretical results based on Faddeev calculations with realistic nucleon-nucleon (NN) forces such as AV18, CD Bonn, and Nijmegen I and II, and their combinations with the three-nucleon forces (3NFs), such as Tucson-Melboume 99 (TM99), Urbana IX, and the coupled-channel potential with A-isobar excitation. Large discrepancies are found between the experimental cross sections and theory with only 2N forces for θc.m. &gt; 90°. The inclusion of 3NFs brings the theoretical cross sections closer to the data but only partially explains this discrepancy. For the analyzing power, no significant improvement is found when 3NFs are included. Relativistic corrections are...

We study the many-body effects in the propagation of the scalar meson in the nuclear medium arising from its coupling to two pion states. We identify the source of the medium effects as the influence of the individual nucleon response arising from their pion clouds. The same modification applies to the QCD scalar susceptibility. It reflects the reshaping of the scalar strength observed in 2π production experiments. While large modifications of the σ propagator occur, we show that the NN scalar potential remains instead unaffected.

The discrete quantum properties of matter are manifest in a variety of phenomena. Any particle that is trapped in a sufficiently deep and wide potential well is settled in quantum bound states. For example, the existence of quantum states of electrons in an electromagnetic ...

The impact of a (I = 0, J P = 1 2 +) Z + (1540) resonance with a width of 5 MeV or more on the K + N (I=0) elastic cross section and on the P 01 phase shift is examined within the KN meson-exchange model of the Jülich group. It is shown that the rather strong enhancement of the cross section caused by the presence of a Z + with the above properties is not compatible with the existing empirical information on KN scattering. Only a much narrower Z + state could be reconciled with the existing data-or, alternatively, the Z + state must lie at an energy much closer to the KN threshold.

Quark-model descriptions of the nucleon-nucleon interaction contain two main ingredients, a quark-exchange mechanism for the short-range repulsion and meson-exchanges for the medium-and long-range parts of the interaction. We point out the special role played by higher partial waves, and in particular the 1 F 3 , as a very sensitive probe for the meson-exchange part employed in these interaction models. In particular, we show that the presently available models fail to provide a reasonable description of higher partial waves and indicate the reasons for this shortcoming.

In this work we revisit the Okamoto-Nolen-Schiffer (ONS) anomaly in the context of four parametrizations of effective hadronic models, two of them with constant couplings between the nucleons and the mesons and two with density-dependent couplings. A Thomas-Fermi approximation is performed and the effects of the isovector-scalar virtual δ(a 0(980)) mesons are investigated since they influence directly the proton and neutron effective masses in opposite ways. The ρ-ω mixing term is claimed to be important in the explanation of the ONS anomaly and is added in our calculations. We have concluded that as far as the ρ-ω mixing term is included, ΔM (Z, N) is clearly larger in models with δ than in models where this meson is not considered, which is not always the case if the coupling is discarded. None of the models is good enough to describe all experimental data, but the models that better describe the experimental values include the δ mesons.

Excluded volume effects are incorporated in the quark meson coupling model to take into account in a phenomenological way the hard core repulsion of the nuclear force. The formalism employed is thermodynamically consistent and does not violate causality. The effects of the excluded volume on in-medium nucleon properties and the nuclear matter equation of state are investigated as a function of the size of the hard core. It is found that in-medium nucleon properties are not altered significantly by the excluded volume, even for large hard core radii, and the equation of state becomes stiffer as the size of the hard core increases.

Measured and calculated cross sections for spin-exchange between alkali atoms and noble gases (specifically sodium and helium) are used to constrain anomalous spin-dependent forces between nuclei at the atomic scale (∼ 10 −8 cm). Combined with existing stringent limits on anomalous shortrange, spin-dependent couplings of the proton, the dimensionless coupling constant for a heretofore undiscovered axial vector interaction of the neutron arising from exchange of a boson of mass < ∼ 100 eV is constrained to be g n A / √ 4πhc < 2 × 10 −3. Constraints are established for a velocityand spin-dependent interaction ∝ (I • v)(K • v), where I and K are the nuclear spins of He and Na, respectively, and v is the relative velocity of the atoms. Constraints on torsion gravity are also considered.

High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (N N) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the ∆-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant N N and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear preference for the predictions in which the 3NF's are included. The majority of the experimental data points is well reproduced by the theoretical predictions. The remaining discrepancies are investigated by inspecting cross sections integrated over certain kinematical variables. The procedure of global comparisons leads to establishing regularities in disagreements between the experimental data and the theoretically predicted values of the cross sections. They indicate deficiencies still present in the assumed models of the 3N system dynamics.

High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (N N) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the ∆-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant N N and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear preference for the predictions in which the 3NF's are included. The majority of the experimental data points is well reproduced by the theoretical predictions. The remaining discrepancies are investigated by inspecting cross sections integrated over certain kinematical variables. The procedure of global comparisons leads to establishing regularities in disagreements between the experimental data and the theoretically predicted values of the cross sections. They indicate deficiencies still present in the assumed models of the 3N system dynamics.

We have calculated the atomic electric dipole moments (EDMs) induced in 199 Hg, 129 Xe, 223 Rn, 225 Ra, and 239 Pu by their respective nuclear Schiff moments S. The results are (in units 10 −17 S(e fm 3) −1 e cm): d(199 Hg) = −2.8, d(129 Xe) = 0.38, d(223 Rn) = 3.3, d(225 Ra) = −8.5, d(239 Pu) = −11. We have also calculated corrections to the parity-and time-invariance-violating (P, Todd) spin-axis interaction constant in TlF. These results are important for the interpretation of atomic and molecular experiments on EDMs in terms of fundamental P, T-odd parameters.

We follow our previous paper on possible cosmological variation of weak scale (quark masses) and strong scale, inspired by data on cosmological variation of the electromagnetic fine structure constant from distant quasar (QSO) absorption spectra. In this work we identify the strange quark mass ms as the most important quantity, and the sigma meson mass as the ingredient of the nuclear forces most sensitive to it. As a result, we claim significantly stronger limits on ratio of weak/strong scale (W = ms/ΛQCD) variation following from our previous discussion of primordial Big-Bang Nucleosynthesis (|δW/W | < 0.006) and Oklo natural nuclear reactor (|δW/W | < 1.2 • 10 −10 ; there is also a non-zero solution δW/W = (−0.56 ± 0.05) • 10 −9) .

There are several factors which lead to a huge enhancement of parity and time invariance violating effects in the Ra atom: very close electronic levels of opposite parity, the large nuclear charge Z and the collective nature of T,Podd nuclear moments. Experiments with Radium may be used to measure it's nuclear anapole, magnetic quadrupole and Schiff moments. Such measurements provide information about parity and time invariance violating nuclear forces and electron-nucleon interactions.

The data from the DISTO Collaboration on the exclusive pp → pK + Λ production acquired at T p = 2.85 GeV have been re-analysed in order to search for a deeply bound K − pp(≡ X) state, to be formed in the binary process pp → K + X. The preliminary spectra of the ∆M K + missingmass and of the M pΛ invariant-mass show, for large transverse-momenta of protons and kaons, a distinct broad peak with a mass M X = 2265 ± 2 MeV/c 2 and a width Γ X = 118 ± 8 MeV/c 2 .

A "theory of everything," in modern physics, is a mathematical theory which attempts to explain or fit all of the laboratory data available today, from the level of elementary particles and nanochips, to the level of gravitational effects between galaxies. Physics today appears to have only two contenders for a theory of everything-superstring or nbrane theory, and a hoped-for merger of quantum loop gravity with the "standard model of physics" (QCD+EWT). This brief paper will attempt to specify a third candidate, which I call "the Q hypothesis." This paper will not argue for the truth of the hypothesis. It will include a few remarks to explain it (with citations to more extensive explanations) , and discuss how the hypothesis might be used in the end. In the end, my claim is that this hypothesis, like the classic Wigner hypothesis 2 , may have computational and empirical value, in helping us to explore and think about the universe. Religious commitment for (or against) specific theories of everything will not really help our fundamental theoretical understanding now, any more than it did when Tycho Brahe proposed his own sacred and elegant theories of strings in the heavens. The simplicity of the hypothesis may be somewhat shocking to some at first, but there is substantial analysis behind it, and the obvious questions have been considered. An appendix added in April, 2008, explains more about the background behind the hypothesis, and the reasons why the earlier P hypothesis currently seems preferable. Specification 1. The theory is defined by starting from a base theory and making two extensions. 2. The base theory is a classical field theory (CFT) in the spirit of Einstein. We postulate a set of smooth continuous fields ϕ i (x,t) over flat Minkowski space, for i = 1 to N, where N is some finite number. The fields form a mathematical vector ϕ. In specific variations of this, the components of ϕ will of course be grouped in ways that include relativistic vectors, some under "topological constraints" (such as the Skyrme constraint that |v| 2 =1 for a vector v made up of some of the components of ϕ), relativistic scalars and so on. We assume that these fields are governed by the classical Lagrange-Euler equations for a specific Lagrangian density L(ϕ, ∂ μ ϕ), which may be represented equivalently in terms

We present results for the 3 P 2-3 F 2 pairing gap in neutron matter with several realistic nucleon-nucleon potentials, in particular with recent, phase-shift equivalent potentials. We find that their predictions for the gap cannot be trusted at densities above ρ ≈ 1.7ρ 0 , where ρ 0 is the saturation density for symmetric nuclear matter. In order to make predictions above that density, potential models which fit the nucleon-nucleon phase shifts up to about 1 GeV are required.