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Motivated by two news states $h_1(1911)$ and $h_1(2316)$ observed by BESIII, we have investigated the mass spectrum and the strong decay properties of the strangeonium mesons within the modified Godfrey-Isgur model by considering the screening effects. We have determined the free parameters using the masses and widths of the well established $s\bar{s}$ states $\phi(1020)$, $\phi(1680)$, $h_1(1415)$, $f_2^\prime(1525)$, and $\phi_3(1850)$. According to our results, $h_1(1911)$ and $h_1(2316)$ could be well explained as states $h_1(2^1P_1)$ and $h_1(3^1P_1)$ $s\bar{s}$ states, respectively. Meanwhile, the possible assignments of $X(2000)$, $\eta_2(1870)$, and $\phi(2170)$ as $3^3S_1$, $1^1D_2$, and $2^3D_1$ are also discussed. Furthermore, the masses and widths of the $2S$, $3S$, $1P$, $2P$, $3P$, $1D$, and $2D$ $s\bar{s}$ states are also given and compared with various theoretical predictions, which is helpful for the observations and confirmations of these states in future.

The mass spectrum of the charmed mesons is investigated by considering the coupled channel effects within the nonrelativistic potential model. The predicted masses of the charmed mesons are in agreement with experimental data. The strong decay properties are further analyzed within the $^3P_0$ model by using numerical wave functions obtained from nonrelativistic potential model. Based on the predicted masses and decay properties, we give a classification of the recently observed charmed states. Especially, we have effectively explained the masses and decay properties of the $D_1^*(2600)$ and $D_1^*(2760)$ by considering the $S$-$D$ mixing. Furthermore, the predicted masses and decay properties of the $2P$ wave states are helpful to search for them experimentally in future.

Based upon a combined formalism of Schwinger-Dyson and Bethe-Salpeter equations in quantum chromodynamics (QCD), we propose a QCD kindred algebraic model for the dressed quark propagator, for the Bethe-Salpeter amplitude of the pion and the electromagnetic quark-photon interaction vertex. We then compute the $\gamma^{*}\pi^0\gamma$ transition form factor $G^{\gamma^{*}\pi^0\gamma}(Q^2)$ for a wide range of photon momentum transfer squared $Q^2$. The quark propagator is expanded out in its perturbative functional form but with dynamically generated dressed quark mass. It has complex conjugate pole singularities in the complex-momentum plane which is motivated by the solution of the quark gap equation with rainbow-ladder truncation of the infinite set of Schwinger-Dyson equations. This complex pole singularity structure of the quark propagator can be associated with a signal of confinement which prevents quarks to become stable asymptotic states. The Bethe-Salpeter amplitude is expressed without a spectral density function, which encapsulate its low and large momentum behaviour. The QCD evolution of the distribution amplitude is also incorporated into our model through the direct implementation of Efremov-Radyushkin-Brodsky-Lepage evolution equations. We include the effects of the quark anomalous magnetic moment in the description of the quark-photon vertex whose infrared enhancement is known to dictate hadronic properties. Once the QCD kindred model is constructed, we calculate the form factor $G^{\gamma^{*}\pi^0\gamma}(Q^2)$ and find it consistent with direct QCD-based studies as well as most available experimental data. It slightly exceeds the conformal limit for large $Q^2$ which might be attributed to the scaling violations in QCD. The associated interaction radius and neutral pion decay width turn out to be compatible with experimental data., Comment: 11 pages, 4 figures

The $\mathcal{V}\to\mathcal{P}\gamma$ and $\eta(\eta^\prime) \to \gamma\gamma$ decays are evaluated within a Dyson-Schwinger and Bethe-Salpeter equations framework (here $\mathcal{V}=\{\rho^{\pm},K^{\star\pm},\phi\}$ and $\mathcal{P}=\{\pi^{\pm},K^{\pm},\eta,\eta^{\prime}\}$). The so-called impulse approximation (IA) is employed in the computation of the decay constants involved and decay widths, and so in the estimation of the associated charge and interaction radii. For their part, the required propagators and vertices stem from a contact interaction model, embedded within a beyond rainbow-ladder (RL) truncation that accounts for the typical ladder exchanges, quark anomalous magnetic moment, as well as the non-Abelian anomaly. While the examined transitions produce decay widths plainly compatible with the available experimental data, those processes involving the $\eta-\eta'$ mesons highlight the incompleteness of the IA when considering beyond RL effects in the interaction kernels., Comment: 9 pages

Given the unique role played by the gravitational form factors (GFFs) in unraveling the internal mechanics of hadrons, we examine the GFFs of ground state pseudoscalar mesons $\pi$, $\eta_c$, $\eta_b$ and the hypothetical {\em strangeonium} $\eta_s(s\bar{s})$. We adopt the coupled framework of Dyson-Schwinger and Bethe-Salpeter equations within a contact interaction, and employ a novel approach to the dressed amputated meson-meson scattering amplitude which makes connection with the energy-momentum tensor and with the GFFs. The resulting GFFs fulfill the anticipated symmetry constraints. The corresponding charge and mass radii and the $D-$term are also computed. We show that the $D-$term for the pseudoscalar mesons is bounded within the $(-1, -1/3)$ range; these bounds correspond to the massless (chiral limit) and infinitely massive cases, respectively. Considering the current interest in the GFFs, understanding the \textit{D}-term of pseudoscalar mesons and their GFFs can provide an important first step for future endeavors in the field., Comment: 10 pages, 5 figures

In this study we investigate novel hybrid structure of silicon nanowires (SiNWs) coated with PANI:metaloxide(MO$_x$) nanoparticles i.e., WO$_3$ and TiO$_2$. The SiNWs were fabricated using MACE, whereas PANI:MO$_x$ were deposited using chemical oxidative polymerization method on SiNWs. To this date little attempts has been done to utilize such hybrid structures for respiratory sensing. The structures were characterized using RAMAN spectroscopy, X-ray diffraction, Electron disperssive spectroscopy, and Scanning electron microscopy. The electrical characterization to obtain respiratory sensing reveals excellent response compared to those obtained for SiNWs:MO$_x$ and SiNWs:PANI. Such enhancement in sensitivity is attributed to formation p-n heterojunction along side with wider conduction channel provided of PANI, increased porosity in SiNWs/PANI:WO$_3$ hybrid structures, providing active sites, increased oxygen vacancies and large surface area compared to that of pure MO$_x$ nanoparticles. Further, an improved drift in base line and sensor stability was established for the structure with PANI:WO$_3$ as compared to the PANI:TiO$_2$., Comment: 12 figures, 16 pages, 44 references

In this work, the $\gamma\to3\pi$ form factor is calculated within the Dyson-Schwinger equations framework using a contact interaction model within the so-called modified rainbow ladder truncation. The present calculation takes into account the pseudovector component in the pion Bethe-Salpeter amplitude (BSA) and $\pi-\pi$ scattering effects, producing a $\gamma\to3\pi$ anomaly which is $1+6\mathcal{R}_\pi^2$ larger than the low energy prediction. Here $\mathcal{R_\pi}$ is the relative ratio of the pseudovector and pseudoscalar components in the pion BSA; with our parameters input, this correction raises the $\gamma\to3\pi$ anomaly by around $10\%$. The main outcome of this work is the unveiling of the origin of such correction, which could be a possible explanation of the discrepancy between the existing experimental data and the low energy prediction. Moreover, it is highlighted how the magnitude of the anomaly is affected in effective theories that require an irremovable ultraviolet cutoff. We find that for both the anomalous processes $\pi\to2\gamma$ and $\gamma\to 3\pi$, the missing contribution to the anomaly can be compensated by the additional structures related with the quark anomalous magnetic moment., Comment: 10 pages, 3 figures, references added

This work proposes an extensive review of laminar and turbulent forced convective heat transfer correlations inside tubes by analyzing both experimental and computational research. Convective heat transfer is influenced by fluid turbulence and boundary layers, with geometry significantly impacting flow conditions. Nusselt number correlations quantifying the heat transfer coefficient are vital for various applications. Previous reviews are summarized regarding nanofluid heat transfer modeling approaches in circular tubes. Additionally, comparisons of tube shapes like circular, elliptical and flat geometries are needed. Recent database searches indicate more experimental than numerical studies have been conducted, with greater focus on turbulent flows. This review systematically evaluates laminar and turbulent forced heat transfer correlations reported in the open literature, discussing both older established work as well as newer findings to provide a holistic perspective. The goal is to better understand convective transportation dependencies for optimized thermal design and performance improvement., Comment: 42 Pages, 14 figures

In the presence of a momentum cutoff, effective theories seem unable to faithfully reproduce the so called chiral anomaly in the Standard Model. A novel prospect to overcome this related issue is discussed herein via the calculation of the $\gamma^{*}\pi^0\gamma$ transition form factor, $G^{\gamma^* \pi^0 \gamma}(Q^2)$, whose normalization is intimately connected with the chiral anomaly and dynamical chiral symmetry breaking (DCSB). To compute such transition, we employ contact interaction model of Quantum Chromodynamics (QCD) under a modified rainbow ladder truncation, which automatically generates a quark anomalous magnetic moment term, weighted by a strenght parameter $\xi$. This term, whose origin is also connected with DCSB, is interpreted as an additional interaction that mimics the complex dynamics beyond the cutoff. By fixing $\xi$ to produce the value of $G^{\gamma^* \pi^0 \gamma}(0)$ dictated by the chiral anomaly, the computed transition form factor, as well as the interaction radius and neutral pion decay width, turn out to be comparable with QCD-based studies and experimental data., Comment: 9 pages, 2 figures

We report on Ge coated silicon nanowires (SiNWs) sensors synthesized with metal assisted chemical etching and qualify their functionality as human respiratory sensor. The sensors were made from p-type single-crystalline (100) silicon wafers using a silver catalysed top-down etching, afterwards coated by 50 nm Ge thin layer using a magnetron sputtering. The Ge post-treatment were performed by rapid thermal annealing (RTA) at 450 and 700 C degrees. The sensors were characterized by X-ray diffraction diffractogram and scanning electron microscopy. It is demonstrated that the sensors are highly sensitive as human breath detectors, with rapid response and frequency detect-ability. They are also shown to be a good candidate for human respiratory diseases diagnoses., Comment: International Semiconductor Conference - CAS 2022, Romania

We report on the structure and electrical characteristics of silicon nanowire arrays prepared by metal assisted chemical etching (MACE) method, investigated by cross-sectional scanning electron microscopy (SEM) and high resolution X-ray diffraction (HR-XRD) methods. SEM micrographs show arrays of merged parallel nanowires, with lengths of 700 nm and 1000 nm, resulted after 1.5 min and 5 min etching time, respectively. X-ray reciprocal space maps (RSMs) around Si (004) reciprocal lattice point indicate the presence of 0D structural defects rather than of extended defects. The photoluminescence spectra exhibit emission bands at 1.70 eV and 1.61 eV, with intensity significantly higher in the case of longer wires and associated with the more defected surface. The transient photoluminescence spectroscopy reveals average lifetime of 60 $\mu$s and 111 $\mu$s for the two SiNW arrays, which correlate with a larger density of defects states in the latest case. The I-V characteristics of the nanowires, show a memristive behavior with the applied voltage sweep rate in the range 5V/s - 0.32V/s. We attribute this behavior to trap states which control the carrier concentration, and model this effect using an equivalent circuit. Photogeneration processes under excitation wavelengths in visible domain, 405 nm - 650 nm, and under light intensity in the range 20 - 100 mW/cm$^2$ provided a further insight into the trap states., Comment: 23 pages 18 figures