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We present off-shell generating functions for all cubic interactions of totally symmetric massless Higher-Spin gauge fields and discuss their properties.
We evaluate interhadron interactions in quenched two-color lattice QCD from Bethe-Salpeter amplitudes, concentrating on S-wave scattering states of two scalar diquarks (uC{gamma}5d). Between two identical scalar diquarks, we observe repulsion in short-range region. We define and evaluate the 'quark-exchange part' in the interaction, which is induced by adding quark-exchange diagrams, or equivalently, by introducing Pauli blocking among some of quarks. The repulsive force in short-distance region arises only from the 'quark-exchange part', and disappears when quark-exchange diagrams are omitted, which is qualitatively consistent with the constituent-quark model picture that a color-magnetic interaction among quarks is the origin of repulsion. We also find a universal long-range attractive force, which enters in any flavor channels of two scalar diquarks and whose interaction range and strength are quark-mass independent.
We summarize the work [1] where we studied the few body system made of several {rho}(770) mesons. Based on the very strong interaction of two {rho}(770) vector mesons in spin 2 and isospin 0, we show that the resonances {rho}3(1690)(3{sup --}), f4(2050)(4{sup ++}), {rho}5(2350)(5{sup --}) and f6(2510)(6{sup ++}) can be interpreted as few body systems made of an increasing number of {rho}(770) particles. The fixed center approximation of the Faddeev equations is used in order to write the multi-body interaction in terms of the elementary two-body scattering amplitudes. Very good agreement with the experimental masses is found. An extension of the model to include also the interaction with K*(895) is discussed.
In this work is considered a complex scalar field theory with higher order derivative terms and interactions. A procedure is developed to quantize consistently this system avoiding the presence of negative norm states. In order to achieve this goal the original real scalar high order field theory is extended to a complex space attaching a complex total derivative to the theory. Next, by imposing reality conditions the complex theory is mapped to a pair of interacting real scalar field theories without the presence of higher derivative terms.
We study a mixture of ultracold spin-half fermionic and spin-one bosonic atoms in a shallow optical lattice where the bosons are coupled to the fermions via both density-density and spin-spin interactions. We consider the parameter regime where the bosons are in a superfluid ground state, integrate them out, and obtain an effective action for the fermions. We carry out a renormalization group analysis of this effective fermionic action at low temperatures, show that the presence of the spinor bosons may lead to a separation of Fermi surfaces of the spin-up and spin-down fermions, and investigate the parameter range where this phenomenon occurs. We also calculate the susceptibilities corresponding to the possible superfluid instabilities of the fermions and obtain their possible broken-symmetry ground states at low temperatures and weak interactions.
Accurate representation of intermolecular forces has been the central task of classical atomic simulations, known as molecular mechanics. Recent advancements in molecular mechanics models have put forward the explicit representation of permanent and/or induced electric multipole (EMP) moments. The formulas developed so far to calculate EMP interactions tend to have complicated expressions, especially in Cartesian coordinates, which can only be applied to a specific kernel potential function. For example, one needs to develop a new formula each time a new kernel function is encountered. The complication of these formalisms arises from an intriguing and yet obscured mathematical relation between the kernel functions and the gradient operators. Here, I uncover this relation via rigorous derivation and find that the formula to calculate EMP interactions is basically invariant to the potential kernel functions as long as they are of the form f(r), i.e., any Green’s function that depends on inter-particle distance. I provide an algorithm for efficient evaluation of EMP interaction energies, forces, and torques for any kernel f(r) up to any arbitrary rank of EMP moments in Cartesian coordinates. The working equations of this algorithm are essentially the same for any kernel f(r). Recently, a few recursive algorithms were proposed to calculate EMP interactions. Depending on the kernel functions, the algorithm here is about 4–16 times faster than these algorithms in terms of the required number of floating point operations and is much more memory efficient. I show that it is even faster than a theoretically ideal recursion scheme, i.e., one that requires 1 floating point multiplication and 1 addition per recursion step. This algorithm has a compact vector-based expression that is optimal for computer programming. The Cartesian nature of this algorithm makes it fit easily into modern molecular simulation packages as compared with spherical coordinate-based algorithms. A software library based on this algorithm has been implemented in C++11 and has been released.
No abstract prepared.
The techniques described in an earlier paper were used to determine masses of 104 asteroids by the method of asteroid-asteroid gravitational interaction. For each of the 104 perturbers, 4 large sets of test particles selected by different criteria were used to calculate 4 mass values from a weighted mean of individual results within each set. The sheer number of test particles and observations ameliorates the effects of random observational errors and the type of systematic errors known to have affected specific observatories at specific times. It also reduces the effect of mismodeled attractions by perturbers other than the one being estimated, because the various test particles are affected to different degrees and in different directions. For most of the perturbers that have been analyzed by others, the results of this study agree reasonably well with values published in the past decade, giving credence to the approach. Thirty-eight of the results appear to be the first published masses for the respective asteroids, and 12 are the first determinations based on asteroid-asteroid interactions. Unrealistic and/or negative masses were obtained for some perturbers. Causes for this phenomenon are discussed and various means to obtain reasonable numbers are evaluated.
The heliopause (HP) is the outer edge of the heliosphere that separates the tenuous and hot heliosheath plasma from the relatively dense and cool magnetized plasma of the local interstellar medium (LISM). As a surface of tangential discontinuity, the HP is subject to both Rayleigh-Taylor (RT) and Kelvin-Helmholtz (KH) instabilities. The coupling between plasma ions and neutral atoms through charge exchange provides an ''effective gravity'' for RT, while shear flows due to the velocity difference between the heliosheath and the interstellar flows can drive KH modes. We derive the linearized dispersion relations for waves propagating along the surface of this discontinuity using a fluid picture, to study the possibility for both RT and KH instabilities, including a second population of energetic neutrals produced by charge exchange interactions between the hot solar wind plasma in the heliosheath with interstellar hydrogen. We show that due to charge exchange interactions, the HP is unconditionally unstable to all perturbations.
Catalytic hydrogenation of CO 2 with renewable H 2 to methanol represents a promising pathway for reducing anthropogenic CO 2 emissions. Catalysts play a key role in enhancing both the hydrogenation rate and methanol selectivity. ZrO 2 is a promising catalyst support, promoter and even active species for CO 2 hydrogenation due to its versatile properties and weak hydrophilic character. Over the past decades substantial progress has been made in designing high performance catalysts and understanding the hydrogenation mechanisms over ZrO 2 -supported catalysts. ZrO 2 interacts with metals and/or other oxides and consequently may affect the CO 2 adsorption and activation, enhance the dissociation of H 2 and spillover of atomic hydrogen, change the reaction pathways and/or the binding of key reaction intermediates for further conversion. The synergistic effects induced by ZrO 2 could be achieved by improving the metal dispersion, modifying surface basicity and interacting with other components (metals, cosupports or promoters). However, although experimental and computational investigations have been extensively performed, the multiple roles of ZrO 2 in the catalytic process are still under debate. In the current Perspective, we use ZrO 2 -containing catalysts as a model system to elucidate the governing principles for designing high performance catalysts with multiple active components for CO 2 hydrogenation to methanol.
The recently observed event excess in MiniBooNE anti-neutrino data is in agreement with the LSND evidence for electron anti-neutrino appearance. We propose an explanation of these data in terms of a (3+1) scheme with a sterile neutrino including non-standard neutrino interactions (NSI) at neutrino production and detection. The interference between oscillations and NSI provides a source for CP violation which we use to reconcile different results from neutrino and anti-neutrino data. Our best fit results imply NSI at the level of a few percent relative to the standard weak interaction, in agreement with current bounds. We compare the quality of the NSI fit to the one obtained within the (3+1) and (3+2) pure oscillation frameworks.
Astrophysical observations of recent years indicate that the universe is composed of a large amount of dark energy (DE) responsible for an accelerated expansion of the universe. Here, we argue that DE can arise entirely from the standard principles of strong interaction physics and quantum entanglement. Good quantitative agreement of our estimate with the observation, without the need for any adjustable parameters, is encouraging.
Recent work by the authors led to the development of a mathematical theory dealing with 'second-order hyperbolic Fuchsian systems', as we call them. In the present paper, we adopt a physical standpoint and discuss the implications of this theory which provides one with a new tool to tackle the Einstein equations of general relativity (under certain symmetry assumptions). Specifically, we formulate the 'Fuchsian singular initial value problem' and apply our general analysis to the broad class of vacuum Gowdy spacetimes with spatial toroidal topology. Our main focus is on providing a detailed description of the asymptotic geometry near the initial singularity of these inhomogeneous cosmological spacetimes and, especially, analyzing the asymptotic behavior of timelike geodesics - which represent the trajectories of freely falling observers - and null geodesics. In particular, we numerically construct Gowdy spacetimes which contain a black hole-like region together with a flat Minkowski-like region. By using the Fuchsian technique, we investigate the effect of the gravitational interaction between these two regions and we study the unexpected behavior of geodesic trajectories within the intermediate part of the spacetime limited by these two regions.
We study the scenario which incorporates dark matter in the minimal left-right symmetric theory at the TeV scale. The only viable candidate is found to be the lightest right-handed neutrino with a mass of keV. In order to satisfy the dark matter relic abundance, the relic yield is diluted by late decays of the two heavier neutrinos. We point out that the QCD phase transition temperature coincidences with the typical freeze-out temperature governed by super-weak right-handed interactions. This helps to alleviate the problem of overproduction and a careful numerical study reveals a narrow window for the mass of the right-handed gauge boson, which is within the reach of the LHC.
The present theoretical status of neutrino interactions in the few-GeV region is reviewed. Quasielastic scattering, pion production and their importance for neutrino oscillation studies are discussed, making emphasis on the open questions that arise in the comparison with new experimental data.
Anomalous U(1){sub A} SUSY GUT models are atractive because they can solve many difficulties in SUSY GUT models. In anomalous U(1){sub A} SUSY GUT models, nucleon decay amplitudes of dim 6 effective interactions are larger than that of dim 5 effective interactions. Then, I discuss dim 6 effective interactions in some models, and predict proton lifetimes for many decay modes by calculating interactions. First, I fix unitary matrices that make Yukawa coupling matrices diagonalize, and predict proton lifetimes. Second, I study uncertainties of these unitary matrices, and show these effects on proton lifetimes. From these results, I show that we can distinguish some models from by nucleon decay.
The oscillation of the muon and electron neutrinos (anti-neutrinos) to tau neutrinos (anti-neutrinos) adds to the muon and electron events sample (both right sign and wrong sign) via leptonic decays of the taus produced through charge current interactions in the detector. We focus on how this contribution affects a precision measurement of the atmospheric mixing parameters and the deviation of v{sub {mu}} {r_reversible} v{sub {tau}} mixing from maximality. We also comment on the tau contamination in the golden and platinum channels.
The QCD beta function extracted from polarized electron proton scattering data obtained at JLab and the lattice simulation in the MOM scheme suggest that the critical flavor number for the presence of IR fixed point is about three. In analyses of Schroedinger functional scheme, however, critical flavor number for the presence of IR fixed point and the conformality is larger than nine.In the QCD analysis, when quarks are expressed in quaternion basis, the product of quaternions are expressed by octonions and the octonion posesses the triality symmetry. Since the triality has the effect of multiplying the falvor number, it could explain the apparent large critical flavor number in the Schroedinger functinal scheme. In this scheme, larger degrees of freedom in adjusting data of different scales on the boundary are necessary than in the MOM scheme.In weak interaction, there is no clear lepton-flavor violation except in the neutrino oscillation. If the triality is assigned to the lepton flavors(e,{mu} and {tau}) and they are assumed to be exact symmetry, or the electro-magnetic interaction preserves tiality, but the strong interaction is triality blind, there is a possibility of explaining the neutrino oscillation through triality mixing of the matter field.The self energy of gluons, ghost and gauge bosons due to self-dual gauge fields and leptonic decays of B,D and D{sub s} mesons are discussed.