Multi-Elliptic Rogue Wave Clusters of the Nonlinear Schrodinger Equation on Different Backgrounds

In this work we analyze the multi-elliptic rogue wave clusters as new solutions of the nonlinear Schr\"odinger equation (NLSE). Such structures are obtained on uniform backgrounds by using the Darboux transformation scheme of order $n$ with the first $m$ evolution shifts that are equal, nonzero, and eigenvalue-dependent, while the imaginary parts of all eigenvalues tend to one. We show that an Akhmediev breather of $n-2m$ order appears at the origin of the $(x,t)$ plane and can be considered as the central rogue wave of the cluster. We show that the high-intensity narrow peak, with characteristic intensity distribution in its vicinity, is enclosed by $m$ ellipses consisting of the first-order Akhmediev breathers. The number of maxima on each ellipse is determined by its index and the solution order. Since rogue waves in nature usually appear on a periodic background, we utilize the modified Darboux transformation scheme to build these solutions on a Jacobi elliptic dnoidal background. We analyze the minor semi-axis of all ellipses in a cluster as a function of an absolute evolution shift. We show that the cluster radial symmetry in the $(x,t)$ plane is violated when the shift values are increased above a threshold. We apply the same analysis on Hirota equation, to examine the influence of a free real parameter and Hirota operator on the cluster appearance. The same analysis can be extended to the infinite hierarchy of extended NLSEs.

Recoupling mechanism for exotic mesons and baryons

The infinite chain of transitions of one pair of mesons (channel I) into another pair of mesons (channel II) can produce bound states and resonances in both channels even if no interactions inside channels exist. These resonances which can occur also in meson-baryon channels are called channel-coupling (CC) resonances. A new mechanism of CC resonances is proposed where transitions occur due to a rearrangement of confining strings inside each channel — the recoupling mechanism. The amplitude of this recoupling mechanism is expressed via overlap integrals of the wave functions of participating mesons (baryons). The explicit calculation with the known wave functions yields the peak at E = 4.12 GeV for the transitions $$ J/\psi +\phi \leftrightarrow {D}_s^{\ast }+{\overline{D}}_s^{\ast } $$ J / ψ + ϕ ↔ D s ∗ + D ¯ s ∗ , which can be associated with χc1 (4140), and a narrow peak at 3.98 GeV with the width 10 MeV for the transitions $$ {D}_s^{-}+{D}_0^{\ast}\leftrightarrow J/\psi +{K}^{\ast -} $$ D s − + D 0 ∗ ↔ J / ψ + K ∗ − , which can be associated with th recently discovered Zcs (3985).

Terbium Doping Graphitic Carbon Nitride Endows Highly Sensitive Ratiometric Fluorescence Assay of Alkaline Phosphatase

Terbium doping graphitic carbon nitride (g-C3N4:Tb) gives rise to two exceptional emissions at λex/λem=290/490 nm and 290/546 nm, with extremely narrow peak width of FWHM <12 nm as well as...

Triangle singularity as the origin of $$X_0(2900)$$ and $$X_1(2900)$$ observed in $$B^+\rightarrow D^+ D^- K^+$$

The LHCb collaboration recently reported the observation of a narrow peak in the $$D^- K^+$$ D - K + invariant mass distributions from the $$B^+\rightarrow D^+ D^- K^+$$ B + → D + D - K + decay. The peak is parameterized in terms of two resonances $$X_0(2900)$$ X 0 ( 2900 ) and $$X_1(2900)$$ X 1 ( 2900 ) with the quark contents $${\bar{c}}{\bar{s}}ud$$ c ¯ s ¯ u d , and their spin-parity quantum numbers are $$0^+$$ 0 + and $$1^-$$ 1 - , respectively. We investigate the rescattering processes which may contribute to the $$B^+\rightarrow D^+ D^- K^+$$ B + → D + D - K + decays. It is shown that the $$D^{*-}K^{*+}$$ D ∗ - K ∗ + rescattering via the $$\chi _{c1}K^{*+}D^{*-}$$ χ c 1 K ∗ + D ∗ - loop and the $${\bar{D}}_{1}^{0}K^{0}$$ D ¯ 1 0 K 0 rescattering via the $$D_{sJ}^{+}{\bar{D}}_{1}^{0}K^{0}$$ D sJ + D ¯ 1 0 K 0 loop can simulate the $$X_0(2900)$$ X 0 ( 2900 ) and $$X_1(2900)$$ X 1 ( 2900 ) with consistent quantum numbers. Such phenomena are due to the analytical property of the scattering amplitudes with the triangle singularities located to the vicinity of the physical boundary.

Search for the N(1685) in ηπ-Photoproduction

The nucleon-like member N(1685) of the speculative baryon antidecuplet denotes one possible explanation for the narrow peak-structure around W = 1.68 GeV observed in the total cross section of η- photoproduction off the neutron. If this baryon existed, it would likely to be seen in other reactions as well. While the aforementioned peak, whatever its nature is, was confirmed by several experiments, claims for signa tures of the N(1685) in other reactions and observables are mainly made by V. Kuznetsov et al. using GRAAL data. Their latest work suggests signals of both N(1685) charge states in all isospin channels of ηπ- photopro duction off the proton and neutron. This contribution reports on challenging these claims with data from the A2 at MAMI experiment employing photon beam energies from Ey=1.43-1.58 GeV. The ηπ0p and ηπ+n final states produced from a hydrogen target were studied and new analysis cuts were tested in order to enhance a possible signal.

Experimental Study on Identification Diffusion Pores, Permeation Pores and Cleats of Coal Samples

Coal pore systems can be commonly classified as diffusion pores, permeation pores and cleats. The classification accuracy influences the coalbed methane (CBM) migration processes from diffusion to permeation and then to outflow, and finally affects the predicted CBM recoverability. To classify coal pore systems precisely, measurements of nuclear magnetic resonance (NMR), mercury intrusion porosimetry (MIP), and nitrogen adsorption isotherm (NAI) are conducted in this paper, and then a comprehensive classification method is proposed. The following cognitions are achieved. NMR spectra can be divided into three categories of three-peak, single narrow peak, and non-three/non-single-narrow peak spectra. The former two categories can be directly used to identify coal pore systems as one peak representing one pore system, and pore systems of the last category can be distinguished by using cumulative amplitudes at the fully water-saturated and centrifuged conditions. Fractal theory suggests that the dividing radii of diffusion–permeation pores obtained by MIP and NAI are quite close, which indicates that the two methods are both effective and accurate. Comparisons between mercury intrusive and cumulative amplitudes indicate that the classification results obtained by measurements of MIP and NMR are similar, which can be a base for transforming transverse relaxation time to pore radius. As a result, the dividing radius of diffusion–permeation pores is about 65 nm, and that of permeation–cleat pores is approximately 600–700 nm.