Pole Exchange Research Articles

Measuring transit-oriented development in Algerian light rail transit lines by using hybrid multi-criteria decision making and open data sources

Selecting transit-oriented development (TOD) sites along light rail transit lines (LRTLs) is difficult for city planners and decision makers. Selecting the actors and the charges involved in the prioritising process, particularly, when selecting between regions with criteria, is critical. Therefore, this study provided a measuring tool to identify TOD opportunities between regions, and outlined its defining criteria through an easy, rapid, and cost-effective method. In this measuring tool, a multi-criteria decision making approach with a hybrid weighting technique was used for ranking eight criteria representing five principles of TOD. Subsequently, simple additive weighting and technique for order of preference by similarity to ideal solution methods were used to rank LRTLs. Furthermore, open data sources were used for data acquisition, and QGIS software was used for data analysis. The application of this method on six LRTLs of Algeria revealed that three tramlines are highly appropriate for TOD implementation, and the rest of the three LRTLs require interventions to some TOD requirements. The density criterion was confirmed as the critical parameter of TOD measurements around tramlines in Algeria followed by exchange poles and transit ridership. The station number and ticket price were the least critical criteria. The results revealed that integrated weighting is critical for investigating TOD as a new planning approach. This result promoted the assignment of accurate weights, which can be useful for decision makers when working in unexplored fields or during indecisive situations. Weighting criteria can be used as guidelines for the major requirements for locations suitable for TOD. Eventually, these results are valuable for future investments of TOD projects along LRTLs or other transit modes.

Study on the Removal of Nitrogen-containing Waste outside the Aquaculture Pond by the Method of Electric Flocculation and Quasi Circulating Aquaculture

When the waste containing ammonia nitrogen is removed by electric flocculation circulating aquaculture, not only the colloidal impurities and suspended impurities are coagulated and precipitated, but also a variety of pollutants and bacteria in the water can be removed due to the oxidation of the anode and the reduction of the cathode. In this project, PWM (pulse width modulation) technology is used to overcome the power consumption problem of traditional electric flocculation method, high-voltage pulse and anode-cathode pole exchange technology is used to overcome the iron consumption and plate passivation problem, and echelon potential method is used to solve the difficulty of plate exchange. Compared with the traditional chemical and biological treatment technology, electrocoagulation can ensure the sustainable development of aquaculture without adding oxidants, flocculants and other chemicals. At present, electronic technology and Internet of things technology are used in aquaculture fields to monitor the water quality data in the pond and control the growth of aquaculture organisms in the most suitable environment in real time, so as to increase income, reduce human power and save water and electricity. Therefore, with mature sensing technology, IOT, Im, cloud computing, big data and AI, we can build an intelligent aquaculture production, marketing and digital service system to improve the overall production efficiency, energy and quality, and accelerate the transformation of aquaculture industry.

Classifying and constraining local four photon and four graviton S-matrices

We study the space of all kinematically allowed four photon and four graviton S-matrices, polynomial in scattering momenta. We demonstrate that this space is the permutation invariant sector of a module over the ring of polynomials of the Mandelstam invariants s, t and u. We construct these modules for every value of the spacetime dimension D, and so explicitly count and parameterize the most general four photon and four graviton S-matrix at any given derivative order. We also explicitly list the local Lagrangians that give rise to these S-matrices. We then conjecture that the Regge growth of S-matrices in all physically acceptable classical theories is bounded by s2 at fixed t. A four parameter subset of the polynomial photon S-matrices constructed above satisfies this Regge criterion. For gravitons, on the other hand, no polynomial addition to the Einstein S-matrix obeys this bound for D ≤ 6. For D ≥ 7 there is a single six derivative polynomial Lagrangian consistent with our conjectured Regge growth bound. Our conjecture thus implies that the Einstein four graviton S-matrix does not admit any physically acceptable polynomial modifications for D ≤ 6. A preliminary analysis also suggests that every finite sum of pole exchange contributions to four graviton scattering also violates our conjectured Regge growth bound, at least when D ≤ 6, even when the exchanged particles have low spin.

Precision analysis of pseudoscalar interactions in neutron beta decays

We analyze the contributions of the one–pion–pole (OPP) exchange, caused by strong low–energy interactions, and the pseudoscalar interaction beyond the Standard Model (BSM) to the correlation coefficients of the neutron β−–decays for polarized neutrons, polarized electrons and unpolarized protons. The strength of contributions of pseudoscalar interactions is defined by the effective coupling constant Cps=Cps(OPP)+Cps(BSM). We show that the contribution of the OPP exchange is of order Cps(OPP)∼−10−5. The effective coupling constant Cps(BSM) of the pseudoscalar interaction BSM can be in principle complex. Using the results, obtained by González-Alonso et al. (2019) [34] we find that the values of the real and imaginary parts of the effective coupling constant Cps(BSM) are constrained by −3.5×10−5<ReCps(BSM)<0 and ImCps(BSM)<−2.3×10−5, respectively. The obtained results can be used as a theoretical background for experimental searches of contributions of interactions BSM in asymmetries of the neutron β−–decays with a polarized neutron, a polarized electron and an unpolarized proton at the level of accuracy of a few parts of 10−5 or even better Abele (2016) [40].

The Po di Adria, Frattesina and the Po Delta between the Middle-Recent Bronze Age and the Early Iron Age

The Po di Adria, Frattesina and the Po Delta between the Middle-Recent Bronze Age and the Early Iron Age

Total π+p cross section extracted from the leading neutron spectra at the LHC

We use the very forward neutron energy spectra measured by the Large Hadron Collider forward (LHCf) experiment at 7 TeV to extract the $\pi^+ p$ total cross section at centre-of-mass energies in the range 2.3$-$3.5 TeV. To do this we have to first isolate the $\pi$-exchange pole in forward neutron production in $pp$ collisions, by evaluating other possible contributions. Namely, those from $\rho$ and $a_2$ exchange, from both eikonal and enhanced screening effects, from migration, from neutron production by $\Delta$-isobar decay and from diffractive nucleon excitations. We discuss the possible theoretical uncertainties due to the fact that the data do not exactly reach the $\pi$ pole. We choose the kinematical domain where the pion contribution dominates and demonstrate the role of the different corrections which could affect the final result.

The Production of Neutral N∗(11052) Resonance with Hidden Beauty from π-p Scattering

We investigate the discovery potential of the predicted neutral hidden beauty N∗(11052) resonance through π-p scattering within an effective Lagrangian approach. Two reactions π-p→K-Σ+ and π-p→ηbn are studied in this work, with nucleon pole exchange as the background. It is found that the contributions of the N∗(11052) resonance give clear peak structures in the magnitude of 1 μb near the threshold of N∗(11052) in the total cross sections. The numerical results indicate that the center of mass energy W≃11–11.1 GeV would be the best energy window for searching the N∗(11052) resonance, where the N∗(11052) signal can be easily distinguished from the background. The COMPASS experiment at CERN’s Super Proton Synchrotron (SPS) with pion beam of ≃280 GeV will be an ideal platform for searching the super-heavy resonance with hidden beauty, which is promising for testing the theoretical results.

Nondiffractive feature of γN → ρ ± N with ρ -meson electromagnetic multipole moments

We investigate photoproduction of charged $\rho$ off the nucleon using $\rho(770)+\pi(140)$ Regge pole exchanges by considering the $\rho$-meson electromagnetic multipole moments. The significance of the Ward identity at the $\gamma\rho\rho$ vertex is emphasized for current conservation in the process. Given $\pi$ exchange with the well-known coupling constants for $\gamma\pi\rho$ and $\pi NN$, we analyze the role of the $\rho$ exchange in the $\gamma p\to \rho^+n$ and $\gamma n\to\rho^-p$ processes without model-dependences except for the magnetic moment $\mu_{\rho^\pm}=\pm2.01$ and electric quadrupole moment ${\cal Q}_{\rho^\pm}=\pm0.027$ fm$^2$ taken from theoretical estimates. The nondiffractive feature of both cross sections is reproduced with a rapid decrease beyond the resonance region by the dominance of $\pi$ exchange over the $\rho$\,. % Cross sections for differential and density matrix elements are presented to compare with existing data. The parity and photon polarization asymmetries are predicted to demonstrate the apparent roles of the $\rho$-meson electromagnetic multipole moments.

Λc*(2940)+photoproduction off the neutron

By assuming that the $\Lambda _{c}^{\ast }(2940)$ is a $pD^{\ast 0}$ molecular state with spin-parity $J^{P}=\frac{1}{2}^{+}$ and $J^{P}=\frac{1}{2}^{-}$, the photoproduction of charmed $\Lambda _{c}^{\ast }(2940)$ baryon in the $\gamma n\rightarrow D^{-}\Lambda _{c}^{\ast }(2940)^{+}$ process is investigated with an effective Lagrangian approach. It is found that the contributions from $t$-channel with $D^{\ast }$ exchange are dominant, while the $s$-channel with nucleon pole exchange give a sizeable contribution around the threshold. The contributions from the $u$-channel and contact term are very small. The total cross section of the $\gamma n\rightarrow D^{-}\Lambda _{c}^{\ast }(2940)^{+}$ reaction is estimated, which indicate it is feasible to searching for the charmed $\Lambda _{c}^{\ast }(2940)$ baryon at the COMPASS experiment.

Anomalous magnetic moment of the muon in a dispersive approach

We present a new general dispersive formalism for evaluating the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon. In the suggested approach, this correction is related to the imaginary part of the muon's electromagnetic vertex function. The latter may be directly related to measurable hadronic processes by means of unitarity and analyticity. As a test we apply the introduced formalism to the case of meson pole exchanges and find agreement with the direct two-loop calculation.

Glueball Regge trajectories in (2+1)-dimensional gauge theories

We compute glueball masses for even spins ranging from 0 to 6, in the D=2+1 SU(2) lattice gauge theory. We do so over a wide range of lattice spacings, and this allows a well-controlled extrapolation to the continuum limit. When the resulting spectrum is presented in the form of a Chew–Frautschi plot we find that we can draw a straight Regge trajectory going through the lightest glueballs of spin 0, 2, 4 and 6. The slope of this trajectory is small and turns out to lie between the predictions of the adjoint-string and flux-tube glueball models. The intercept we find, α 0∼−1, is much lower than is needed for this leading trajectory to play a ‘Pomeron-like’ role of the kind it is often believed to play in D=3+1. We elaborate the Regge theory of high-energy scattering in 2 space dimensions, and we conclude, from the observed low intercept, that high-energy glueball scattering is not dominated by the leading Regge pole exchange, but rather by a more complex singularity structure in the region 0⩽Re λ⩽1/2 of the complex angular momentum λ plane. We show that these conclusions do not change if we go to larger groups, SU( N>2), and indeed to SU(∞), and we contrast all this with our very preliminary calculations in the D=3+1 SU(3) gauge theory.

Gluonic effects in vector meson photoproduction at large momentum transfers

Nonperturbative QCD mechanisms are of fundamental importance in strong interaction physics. In particular, the flavor singlet axial anomaly leads to a gluonic pole mechanism which has been shown to explain the η′ mass, violations of the OZI rule and more recently the proton spin. We analyze under which conditions the interaction derived from the gluonic pole exchange might explain the high momentum transfer behavior of the photoproduction cross sections of vector mesons at JLab energies. We provide therefore additional support to our scenario in which nonperturbative QCD mechanisms are relevant for the interpretation of the data.

How open charm production and scaling violations probe the rightmost hard BFKL pole exchange

In 1994 Zakharov and the present authors argued that in color dipole (CD) BFKL approach to DIS excitation of open charm at moderately large Q2 is dominated by hard BFKL exchange. In view of the rapid accumulation of the experimental data on small-x charm structure function of the proton F2cc from HERA, we subject the issue of dominance of the rightmost hard BFKL pole exchange to further scrutiny. Based on CD BFKL-Regge factorization we report parameter-free predictions for the charm structure function F2cc and show that the background to the dominant rightmost hard BFKL exchange from subleading hard BFKL and soft-pomeron exchanges is negligible small from real photo-production to DIS at Q2 lsim 50-100 GeV2. The agreement with the experiment is good and lends strong support for the intercept of the rightmost hard BFKL pole DeltaPom=alphaPom-1=0.4 as found in 1994 in the color dipole approach. We comment on the related determination of DeltaPom from the x-dependence of the longitudinal structure function FL(x,Q2) and of the scaling violation dF2/dlog Q2 taken at a suitable value of Q2. \

BOOTSTRAP OF THE SCALAR SECTOR IN TOP–ANTITOP SCATTERING AMPLITUDE

Based on the top-condensate model of Nambu and Bardeen et al., it is pointed out that a bootstrap of the scalar sector occurs in top–antitop scattering amplitude in that the ladder sum of Higgs pole exchange diagrams in one channel reproduces a Higgs pole in the crossed-channel. This result is exact whenever color flows simultaneously in both channel directions e.g. for Nc = 1. Solutions are obtained that are compatible with the condensate models such as the top-color models which imply large top-Yukawa couplings at the top mass.

Pôles d'échanges et intermodalités, un enjeu pour la ville de demain, l'exemple de Lille-Flandres / Lille-Europe

Urban policy makers and planners in western Europe are beginning that land use end transport trends are environmentally unsustainable, large cities such as Lille Metropole face growth in the use of motor vehicles. If cities are to be sustainable socially, economically and environmentally, land use and transport must be recognized, and treated, as an integrated system. The Central Urban Pole Exchange Center with an excellent accessibility at different scales may be a positive experience to change the modal-split in the future ! Even when they have, the development is too recent that it is soon to judge the effectiveness of the policy. Nevertheless, it is worth commenting on several characteristics. Co-ordination between the local, strategic and regional scales and between land-use planning is essential.

Evidence for a scalar κ(900) resonance inπKscattering

Motivated by the ${1/N}_{c}$ expansion, we study a simple model in which the $\ensuremath{\pi}K$ scattering amplitude is the sum of a current-algebra contact term and resonance pole exchanges. This phenomenological model is crossing symmetric and, when a putative light strange scalar meson \ensuremath{\kappa} is included, satisfies the unitarity bounds to well above 1 GeV. The model also features chiral dynamics, vector meson dominance and appropriate interference between the established ${K}_{0}^{*}(1430)$ resonance and its predicted background. We briefly discuss the physical significance of the results and directions for further work.

Mechanisms of the reactionπ−p→a00(980)n→π0ηnat high energies

The main dynamical mechanisms of the reaction $\pi^-p \rightarrow a^0_0 (980)n \rightarrow \pi^0\eta n$ at high energies, currently investigated at Serpukhov and Brookhaven, are considered in detail. It is shown that the observed forward peak in its differential cross section can be explained within the framework of the Regge pole model only by the conspiring $\rho_2$ Regge pole exchange. The tentative estimates of the absolute $\pi^-p \rightarrow a^0_0(980)n \rightarrow \pi^0\eta n$ reaction cross section at $P_{lab}^{\pi^-} = 18$ GeV/c are obtained: $\sigma\approx200$ nb and, in the forward direction, $d\sigma/dt\approx940$ nb/GeV$^2$. The contribution of the one pion exchange, which is forbidden by $G$-parity and which can rise owing to the $f^0_0(980)-a^0_0(980)$ mixing, is also estimate. A role of the Regge cuts in the non-flip helicity amplitude is briefly examined and a conclusion is made that the contributions of the cuts have to be inessential in comparison with the conspiring $\rho_2$ Regge pole exchange.

Simple description ofππscattering to 1 GeV

Motivated by the $\frac{1}{{N}_{c}}$ expansion, we present a simple model of $\ensuremath{\pi}\ensuremath{\pi}$ scattering as a sum of a current-algebra contact term and resonant pole exchanges. The model preserves crossing symmetry as well as unitarity up to 1.2 GeV. Key features include chiral dynamics, vector meson dominance, a broad low energy scalar ($\ensuremath{\sigma}$) meson, and a Ramsauer-Townsend mechanism for the understanding of the 980 MeV region. We discuss in detail the regularization (corresponding to rescattering effects) necessary to make all these nice features work.

Four Momentum Transfer between the Fireballs in Carbon‐Emulsion Interaction at 4.5 GeV/c per Nucleon

AbstractThis paper presents an analysis of the four momentum transfer between the fireballs in the events produced in 12C‐Emulsion interaction at 4.5 GeV/c per nucleon. The results have been compared with the predications of the Pomeranchuk Pole exchange model.

Three-body Coulomb effects in neutral-particle-exchange singularity

In a three-body model with Coulomb interactions the Faddeev equations for the Alt-Grassberger-Sandhas transition operators are used to find the leading term of the neutron-transfer amplitude near the exchange singularity in the cos θ plane. We derive formulae containing three-body Coulomb effects for the renormalization of the second-order exchange pole in the calculation of observables, such as the cross section and polarizations.