Narrow States Research Articles

Strong decays of the 1P and 2D doubly charmed states

We perform a systematical investigation of the strong decay properties of the low-lying $1P$- and $2D$-wave doubly charmed baryons with the $^3P_0$ quark pair creation model. The main predictions include: (i) in the $\Xi_{cc}$ and $\Omega_{cc}$ family, the $1P~\rho$ mode excitations with $J^P=1/2^-$ and $3/2^-$ should be the fairly narrow states. (ii) For the $1P~\lambda$ mode excitations, $|^2P_{\lambda}\frac{3}{2}^-\rangle$ and $|^4P_{\lambda}\frac{3}{2}^-\rangle$ have a width of $\Gamma\sim150$ MeV, and mainly decay into the $J^P=3/2^+$ ground state. Meanwhile, $|^2P_{\lambda}\frac{1}{2}^-\rangle$ and $|^4P_{\lambda}\frac{5}{2}^-\rangle$ are the narrow states with a width of $\Gamma\sim40$ MeV, and mainly decay into the ground state with $J^P=1/2^+$. (iii) The $2D_{\rho\rho}$ states mainly decay via emitting a heavy-light meson if their masses are above the threshold of $\Lambda_cD$ or $\Xi_cD$, respectively. Their strong decay widths are sensitive to the masses and can reach several tens MeV. (iv) The $2D_{\lambda\lambda}$ states may be broad states with a width of $\Gamma>100$ MeV. It should be emphasized that the states with $J^P=3/2^+$ and $5/2^+$ mainly decay into the ground state with $J^P=3/2^+$ plus a light-flavor meson, while the states with $J^P=1/2^+$ and $7/2^+$ mainly decay into the ground state with $J^P=1/2^+$ plus a light-flavor meson.

Observation of excited Ωc charmed baryons in e+e− collisions

Using the entire Belle data sample of 980 ${\rm fb}^{-1}$ of $e^+e^-$ collisions, we present the results of a study of excited $\Omega_c$ charmed baryons in the decay mode $\Xi_c^+K^-$. We show confirmation of four of the five narrow states reported by the LHCb Collaboration: the $\Omega_c(3000)$ , $\Omega_c(3050)$, $\Omega_c(3066)$, and $\Omega_c(3090)$.

Generalized Ehrenfest Relations, Deformation Quantization, and the Geometry of Inter-model Reduction

This study attempts to spell out more explicitly than has been done previously the connection between two types of formal correspondence that arise in the study of quantum–classical relations: one the one hand, deformation quantization and the associated continuity between quantum and classical algebras of observables in the limit $$\hbar \rightarrow 0$$ , and, on the other, a certain generalization of Ehrenfest’s Theorem and the result that expectation values of position and momentum evolve approximately classically for narrow wave packet states. While deformation quantization establishes a direct continuity between the abstract algebras of quantum and classical observables, the latter result makes in-eliminable reference to the quantum and classical state spaces on which these structures act—specifically, via restriction to narrow wave packet states. Here, we describe a certain geometrical re-formulation and extension of the result that expectation values evolve approximately classically for narrow wave packet states, which relies essentially on the postulates of deformation quantization, but describes a relationship between the actions of quantum and classical algebras and groups over their respective state spaces that is non-trivially distinct from deformation quantization. The goals of the discussion are partly pedagogical in that it aims to provide a clear, explicit synthesis of known results; however, the particular synthesis offered aspires to some novelty in its emphasis on a certain general type of mathematical and physical relationship between the state spaces of different models that represent the same physical system, and in the explicitness with which it details the above-mentioned connection between quantum and classical models.

Transient Sub-bandgap States in Halide Perovskite Thin Films.

Metal halide perovskites are promising solar energy materials, but their mechanism of action remains poorly understood. It has been conjectured that energetically stabilized states such as those corresponding to polarons, quasiparticles in which the carriers are dressed with phonons, are responsible for their remarkable photophysical properties. Yet, no direct evidence of polarons or other low-energy states have been reported despite extensive efforts. Such states should manifest as below bandgap features in transient absorption and photoluminescence measurements. Here, we use single-particle transient absorption microscopy on MAPbI3 (MA = methylammonium) to unambiguously identify spectrally narrow sub-bandgap states directly; we demonstrate that such signals are completely averaged away in ensemble measurements. Carrier temperature-dependent studies suggest that hot carriers are directed toward transient low-energy states which are immune from permanent defects and traps, thereby giving rise to low carrier recombination rates and ultimately high power conversion efficiency in devices. The utilization of short-lived sub-bandgap states may be a key design principle that propels widespread use of highly heterogeneous materials in optoelectronic applications.

Synthesis and Raman spectroscopy of a layered SiS2 phase at high pressures.

Dichalcogenides are known to exhibit layered solid phases, at ambient and high pressures, where 2D layers of chemically bonded formula units are held together by van der Waals forces. These materials are of great interest for solid-state sciences and technology, along with other 2D systems such as graphene and phosphorene. SiS2 is an archetypal model system of the most fundamental interest within this ensemble. Recently, high pressure (GPa) phases with Si in octahedral coordination by S have been theoretically predicted and also experimentally found to occur in this compound. At variance with stishovite in SiO2, which is a 3D network of SiO6 octahedra, the phases with octahedral coordination in SiS2 are 2D layered. Very importantly, this type of semiconducting material was theoretically predicted to exhibit continuous bandgap closing with pressure to a poor metallic state at tens of GPa. We synthesized layered SiS2 with octahedral coordination in a diamond anvil cell at 7.5-9 GPa, by laser heating together elemental S and Si at 1300-1700 K. Indeed, Raman spectroscopy up to 64.4 GPa is compatible with continuous bandgap closing in this material with the onset of either weak metallicity or of a narrow bandgap semiconductor state with a large density of defect-induced, intra-gap energy levels, at about 57 GPa. Importantly, our investigation adds up to the fundamental knowledge of layered dichalcogenides.

Heavy Baryons in the Chiral Quark--Soliton Model: A Possibility for Exotica?

We discuss possible interpretation of five excited $\Omega^0_c$ states within the Chrial Quark Soliton Model. We show that it is not possible to interpret all five $\Omega^0_c$'s as parity minus excitations and argue that two narrowest states are pentaquarks belonging to the SU(3) representation $\overline{15}$.

Exploring the electronic structure and speciation of aqueous and colloidal Pu with high energy resolution XANES and computations.

Pu L3 HR-XANES and FEFF9 computations provide evidence for band-like 6d states in colloidal Pu contrasting to narrow 6d states in molecular Pu(iv). Pu L3 HR-XANES is valuable for bond length estimation in plutonyl, whereas Pu M5 HR-XANES is an advanced tool for analysing Pu redox states and 5f unoccupied density of states.

Systematic Study of Vortex Pinning and a Liquid–Glass Phase Transition in BaFe2–xNixAs2 Single Crystals

The vortex pinning and liquid-glass transition have been studied in BaFe2–xNixAs2 single crystals with different doping levels (x = 0.065, 0.093, 0.1, 0.14, 0.18). We found that Ni-doped Ba-122 has rather narrow vortex-liquid state region. Our results show that the temperature dependence of the resistivity as well as I−V characteristics of Ni-doped Ba-122 is consistent with 3D vortex-glass model. It was found that -pinning gives the main contribution to overall pinning in 122 Ni-doped system. The vortex phase diagrams for different doping levels were built based on the obtained data of temperature of the vortex-glass transition Tg and the upper critical magnetic field Hc2.

Soliton-Potential Interactions for Nonlinear Schrödinger Equation in $\mathbb{R}^3$

In this work we mainly consider the dynamics and scattering of a narrow soliton of NLS equation with a potential in $\mathbb{R}^3$, where the asymptotic state of the system can be far from the initial state in parameter space. Specifically, if we let a narrow soliton state with initial velocity $\upsilon_{0}$ to interact with an extra potential $V(x)$, then the velocity $\upsilon_{+}$ of outgoing solitary wave in infinite time will in general be very different from $\upsilon_{0}$. In contrast to our present work, previous works proved that the soliton is asymptotically stable under the assumption that $\upsilon_{+}$ stays close to $\upsilon_{0}$ in a certain manner.

Fano resonance induced by stub and applied in nanosensor

This paper mainly investigates the influence of stub resonator on the structure comprising a metal-insulator-metal (MIM), a stub and a groove resonator and its application in nanosensor. We make use of the finite element method (FEM) to gain the simulation results which reveal the Fano resonance originates from the interaction between the stub resonator inducing the narrow discrete state and the groove inducing the continuous spectrum. Meanwhile, when changing the parameters of the structure, we find the asymmetrical linear shape and the resonant wavelength have also changed. And we also explore the influence of stub position on the Fano resonance and explain the mechanism of flipping the Fano resonance when changing stub position. To further explore the influence of stub on our system, we add two stubs and excited multiple Fano resonances. We apply the structure as a plasmonic sensor with a sensitivity of 1300 nm/RIU and a figure of merit of about 4.038×103 and the characteristics can find extensive applications for nano devices.

Electroencephalography Based Analysis of Working Memory Load and Affective Valence in an N-back Task with Emotional Stimuli

Most brain-based measures of the electroencephalogram (EEG) are used in highly controlled lab environments and only focus on narrow mental states (e.g., working memory load). However, we assume that outside the lab complex multidimensional mental states are evoked. This could potentially create interference between EEG signatures used for identification of specific mental states. In this study, we aimed to investigate more realistic conditions and therefore induced a combination of working memory load and affective valence to reveal potential interferences in EEG measures. To induce changes in working memory load and affective valence, we used a paradigm which combines an N-back task (for working memory load manipulation) with a standard method to induce affect (affective pictures taken from the International Affective Picture System (IAPS) database). Subjective ratings showed that the experimental task was successful in inducing working memory load as well as affective valence. Additionally, performance measures were analyzed and it was found that behavioral performance decreased with increasing workload as well as negative valence, showing that affective valence can have an effect on cognitive processing. These findings are supported by changes in frontal theta and parietal alpha power, parameters used for measuring of working memory load in the EEG. However, these EEG measures are influenced by the negative valence condition as well and thereby show that detection of working memory load is sensitive to affective contexts. Unexpectedly, we did not find any effects for EEG measures typically used for affective valence detection (Frontal Alpha Asymmetry (FAA)). Therefore we assume that the FAA measure might not be usable if cognitive workload is induced simultaneously. We conclude that future studies should account for potential context-specifity of EEG measures.

Theoretical and legal investigation of the concept, essences and signs of public administration.

In the article was investigated that a primary category in relation to a concept “state administration” is a concept “management”, that has multifaceded and interdisciplinary character. A “management” on the essence means activity from guidance anybody or by something, influence of imperious subject another subjects. As a sphere of practical activity state administration is characterized by the decision of problems of state organization and adjusting of public life. Approaches of state administration concept understanding was analyzed. In the wide understanding state administration characterizes all activity of the state after organizing influence from the side of the special legal subjects on public relations. The representatives of the narrow going near state administration understand the last as an independent type of activity of the state, that he is carried out by certain part of public organs. Legal essence of state administration consists in execution laws and direct guidance by the different spheres of life of the state and society. It is set that to the most characteristic signs of state administration belong: legally-imperious and prescriptive character; spreads to all members of society and has national character; activity of organs of state administration comes true on founding and on implementation of laws; has organizational maintenance; characterized by purposefulness; comes true on permanent basis and carries active character. On the basis of the signs marked higher, state administration is suggested to understand as the intraorganization, executive and administrative, systematic, purposeful and subordinate activity of public organs, sent to implementation of current legislation and adjusting of different sort of public relations in the different spheres of functioning of the state.

Implications of heavy quark-diquark symmetry for excited doubly heavy baryons and tetraquarks

We give heavy quark-diquark symmetry predictions for doubly heavy baryons and tetraquarks in light of the recent discovery of the ${\mathrm{\ensuremath{\Xi}}}_{cc}^{++}$ by LHCb. For five excited doubly charm baryons that are predicted to lie below the ${\mathrm{\ensuremath{\Lambda}}}_{c}D$ threshold, we give predictions for their electromagnetic and strong decays using a previously developed chiral Lagrangian with heavy quark-diquark symmetry. Based on the mass of the ${\mathrm{\ensuremath{\Xi}}}_{cc}^{++}$, the existence of a doubly heavy bottom $I=0$ tetraquark that is stable to strong and electromagnetic decays has been predicted. If the mass of this state is below 10405 MeV, as predicted in some models, we argue using heavy quark-diquark symmetry that the ${J}^{P}={1}^{+}\text{ }\text{ }I=1$ doubly bottom tetraquark state will lie just below the open bottom threshold and likely be a narrow state as well. In this scenario, we compute strong decay width for this state using a new Lagrangian for doubly heavy tetraquarks which is related to the singly heavy baryon Lagrangian by heavy quark-diquark symmetry.

New Ωc0 baryons discovered by LHCb as the members of 1P and 2S states

Inspired by the newly observed $\Omega_c^0$ states at LHCb, we decode their properties by performing an analysis of mass spectrum and decay behavior. Our studies show that the five narrow states, i.e., $\Omega_c(3000)^0$, $\Omega_c(3050)^0$, $\Omega_c(3066)^0$, $\Omega_c(3090)^0$, and $\Omega_c(3119)^0$, could be grouped into the $1P$ states with negative parity. Among them, the $\Omega_c(3000)^0$ and $\Omega_c(3090)^0$ states could be the $J^P=1/2^-$ candidates, while $\Omega_c(3050)^0$ and $\Omega_c(3119)^0$ are suggested as the $J^P=3/2^-$ states. $\Omega_c(3066)^0$ could be regarded as a $J^P=5/2^-$ state. Since the the spin-parity, the electromagnetic transitions, and the possible hadronic decay channels $\Omega_c^{(\ast)}\pi$ have not been measured yet, other explanations are also probable for these narrow $\Omega_c^0$ states. Additionally, we discuss the possibility of the broad structure $\Omega_c(3188)^0$ as a $2S$ state with $J^P=1/2^+$ or $J^P=3/2^+$. In our scheme, $\Omega_c(3119)^0$ cannot be a $2S$ candidate.

Strong and radiative decays of the doubly charmed baryons

We have systematically studied the strong and radiative decays of the low-lying $1P$-wave doubly charmed baryons. Some interesting observations are: (i) The states $\Xi_{cc}^*$ and $\Omega_{cc}^*$ with $J^P=3/2^+$ have a fairly large decay rate into the $\Xi_{cc}\gamma$ and $\Omega_{cc}\gamma$ channels with a width $\sim 15$ and $\sim7$ keV, respectively. (ii) The lowest lying excited doubly charmed baryons are dominated by the $1P$ $\rho$ mode excitations, which should be quite narrow states. They decay into the ground state with $J^P=1/2^+$ through the radiative transitions with a significant ratio. (iii) The total decay widths of the first orbital excitations of $\lambda$ mode ($1P_{\lambda}$ states with $J^P=1/2^-$, $3/2^-$, $5/2^-$) are about $\Gamma\sim100$ MeV, and the ratio between the radiative and hadronic decay widths is about $\mathcal{O}(10^{-3})$.

Narrow exotic tetraquark mesons in large- Nc QCD

Discussing four-point Green functions of bilinear quark currents in large-$N_c$ QCD, we formulate rigorous criteria for selecting diagrams appropriate for the analysis of potential tetraquark poles. We find that both flavor-exotic and cryptoexotic (i.e., flavor-nonexotic) tetraquarks, if such poles exist, have a width of order $O(1/N_c^2)$, so they are parametrically narrower compared to the ordinary $\bar qq$ mesons, which have a width of order $O(1/N_c)$. Moreover, for flavor-exotic states, the consistency of the large-$N_c$ behavior of "direct" and "recombination" Green functions requires two narrow flavor-exotic states, each coupling dominantly to one specific meson-meson channel.

No Evidence of Narrowly Defined Cognitive Penetrability in Unambiguous Vision.

The classical notion of cognitive impenetrability suggests that perceptual processing is an automatic modular system and not under conscious control. Near consensus is now emerging that this classical notion is untenable. However, as recently pointed out by Firestone and Scholl, this consensus is built on quicksand. In most studies claiming perception is cognitively penetrable, it remains unclear which actual process has been affected (perception, memory, imagery, input selection or judgment). In fact, the only available “proofs” for cognitive penetrability are proxies for perception, such as behavioral responses and neural correlates. We suggest that one can interpret cognitive penetrability in two different ways, a broad sense and a narrow sense. In the broad sense, attention and memory are not considered as “just” pre- and post-perceptual systems but as part of the mechanisms by which top-down processes influence the actual percept. Although many studies have proven top-down influences in this broader sense, it is still debatable whether cognitive penetrability remains tenable in a narrow sense. The narrow sense states that cognitive penetrability only occurs when top-down factors are flexible and cause a clear illusion from a first person perspective. So far, there is no strong evidence from a first person perspective that visual illusions can indeed be driven by high-level flexible factors. One cannot be cognitively trained to see and unsee visual illusions. We argue that this lack of convincing proof for cognitive penetrability in the narrow sense can be explained by the fact that most research focuses on foveal vision only. This type of perception may be too unambiguous for transient high-level factors to control perception. Therefore, illusions in more ambiguous perception, such as peripheral vision, can offer a unique insight into the matter. They produce a clear subjective percept based on unclear, degraded visual input: the optimal basis to study narrowly defined cognitive penetrability.

Fano resonances in photonic crystal nanobeams side-coupled with nanobeam cavities

Fano resonances usually arise when a narrow resonance or discrete state and a broad resonance or continuum state are coupled. In this paper, we theoretically and numerically study asymmetric Fano line shape realized in a photonic crystal nanobeam (PCN) side-coupled with a photonic crystal nanobeam cavity (PCNC). Asymmetric transmission profiles with a transmission peak and a transmission valley are obtained for a low index concentrated cavity mode. The transmission valley, associated with the destructive interference, of our PCN-PCNC structures is deeper than that of a waveguide or Fabry-Perot resonator side-coupled with a PCNC structure. Through changing the position of the photonic band gap (PBG) of the PCN, we can utilize the high or low frequency band edge modes and the Fano transmission profiles can be further controlled. The transmission spectra of our PCN-PCNC structures can be well fitted by the Fano resonance formula and agree qualitatively with the prediction made by the temporal coupled mode theory. By using the band edge modes of the PCN as the continuum state instead of a usual broad resonance, we have demonstrated a new way to generate a prominent Fano resonance. Our PCN-PCNC structures are compact and feasible to achieve large-scale high-performance integrated photonic devices, such as optical modulators or switches.

Measurements of charge state distributions of 0.74 and 1.4 MeV/u heavy ions passing through dilute gases

In many modern heavy-ion accelerator facilities, gas strippers are used to increase the projectile charge state for improving the acceleration efficiency of ion beams to higher energies. For this application, the knowledge on the behavior of charge state distributions of heavy-ions after passing through dilute gases is of special interest. Charge state distributions of uranium ($^{238}\mathrm{U}$), bismuth ($^{209}\mathrm{Bi}$), titanium ($^{50}\mathrm{Ti}$), and argon ($^{40}\mathrm{Ar}$) ion beams with energies of $0.74\text{ }\mathrm{MeV}/\mathrm{u}$ and $1.4\text{ }\mathrm{MeV}/\mathrm{u}$ after passing through hydrogen (${\mathrm{H}}_{2}$), helium (He), carbon dioxide (${\mathrm{CO}}_{2}$), nitrogen (${\mathrm{N}}_{2}$), oxygen (${\mathrm{O}}_{2}$), neon (Ne), and argon (Ar) gases were measured. Gas stripper target thicknesses up to $100\text{ }\text{ }\ensuremath{\mu}\mathrm{g}/{\mathrm{cm}}^{2}$ were applied. The observed behavior of the charge state distributions, including their width and mean charge state, are discussed. The measurements show the highest equilibrium charge state at $1.4\text{ }\mathrm{MeV}/\mathrm{u}$ for $^{238}\mathrm{U}$ on ${\mathrm{H}}_{2}$ gas of $29.2\ifmmode\pm\else\textpm\fi{}1.2$. Narrow charge state distributions are observed for $^{238}\mathrm{U}$ and $^{209}\mathrm{Bi}$ on ${\mathrm{H}}_{2}$ and He gas, which are highly beneficial, e.g., for the production of beams of high intensities in accelerators.

Control of plasmon resonance by mode coupling in metal-dielectric nanostructures

We present an approach to control the spectral response of plasmonic metal-dielectric nanostructure through resonant scattering. The resonant coupling scheme is based on mixing of a broad surface state with a narrow resonant state. The spectral response of the Au-Si nanostructure is highly tunable by controlling the coupling strength of the two states. The nanostructure also shows a highly asymmetric and narrow resonance profile in the reflection spectrum. The calculated quality factor of a resonant mode in the proposed structure is about 93 around λ0 = 750 nm. The proposed metal-dielectric nanostructure has great potential to improve the quality factor of the existing surface plasmon resonance systems.