Phenomenological Potential Model Research Articles

Photoproduction of fully charmed tetraquark at electron-ion colliders

In this work, we investigate the inclusive photoproduction of the C-odd, S-wave fully charmed tetraquark at electron-ion colliders within the nonrelativistic QCD (NRQCD) factorization framework, at the lowest order in velocity and αs. The value of the NRQCD long-distance matrix element is estimated from two phenomenological potential models. Our studies reveal that the photoproduction of the 1+− fully charmed tetraquark may be difficult to observe at HERA and the EicC; nevertheless, its observation prospects at the EIC appear to be bright. Published by the American Physical Society 2024

Producing fully-charmed tetraquarks via charm quark fragmentation in colliders

Within the framework of nonrelativistic QCD (NRQCD), we calculate the fragmentation function for a charm quark into an S-wave fully-charmed tetraquark, denoted as T4c. The charm-to-T4c fragmentation function is expressed as a sum of products of the perturbatively calculable short-distance coefficients and the nonperturbative long-distance matrix elements (LDMEs). The short-distance coefficients are ascertained through the perturbative matching procedure at lowest order in αs expansion. The LDMEs are approximated using the T4c four-body wave functions at the origin, which have been evaluated by various phenomenological potential models in literature. Incorporating the celebrated QCD factorization and the charm-to-T4c fragmentation function, we predict the T4c production rate at high transverse momentum pT regime in colliders. Both the differential distribution over pT and the integrated cross sections are predicted at the LHC. The cross sections for T4c states production can reach several femtobarns to several hundreds femtobarns, suggesting a substantial potential for T4c event production at the LHC. Additionally, we estimate for the photoproduction of T4c in electron-proton (ep) collisions. It is observed that the cross sections for these processes are moderate at the HERA and EIC, and relatively small at the EicC. Given the luminosities of these colliders, the prospect of detecting these fully-charmed tetraquarks at ep colliders is somewhat challenging.

An improved simple model for α decay half-lives*

Abstract In this paper, using the α particle preformation probabilities from Xu et al. [Xu and Ren, Nucl. Phys. A 760, 303 (2005)], which were extracted by fitting experimental half-lives of α decay, based on a phenomenological harmonic oscillator potential model (HOPM) [Bayrak, J Phys G 47, 025102 (2020)], refitting 178 α decay half-lives of even-even nuclei obtained from the latest nuclear property table NUBASE2020, we obtain the only one adjustable parameter MeV in the HOPM, i.e., the depth of nuclear potential. The corresponding root-mean-square (rms) deviation is . Furthermore, to consider the contribution of centrifugal potential to unfavored α decay half-lives, adding a new term (d and l are the adjustable parameter and orbital angular momentum carried away by emitted α particle) to the logarithmic form of favored α decay half-lives under the HOPM framework, we propose an improved simple model (ISM) for calculating favored and unfavored α decay half-lives. Fitting the experimental half-lives of 205 unfavored α decay, we obtain . The ISM is used to calculate the unfavored α decay half-lives of 128 odd-A and 77 odd-odd nuclei. The results improve by 54.2% and 53.6%, respectively, compared with HOPM. In addition, we extend the ISM to predict the α decay half-lives of 144 nuclei with , and 120. For comparison, the improved model with eight parameters (DUR) proposed by Deng et al. [Deng, Phys. Rev. C 101, 034307 (2020)] and the modified universal decay law (MUDL) proposed by Soylu et al. [Soylu, Nucl. Phys. A 1013, 122221 (2021)] are also used. The predictions of these models and/or formulas are generally consistent with each other.

Approximate bound state solutions of the fractional Schr\"{o}dinger equation under the spin-spin-dependent Cornell potential

In this work, the approximate bound state solutions of the fractional Schr\"{o}dinger equation under a spin-spin-dependent Cornell potential are obtained via the convectional Nikiforov-Uvarov approach. The energy spectra are applied to obtain the mass spectra of the heavy mesons such as bottomonium, charmonium and bottom-charm. The masses for the singlet and triplet spin numbers increase as the quantum numbers increase. The fractional Schr\"{o}dinger equation improves the mass spectra compared to other theoretic masses. The bottomonium masses agree with the experimental results where percentage errors for fractional parameters of $\beta =1,\alpha =0.97$ and $\beta =1,\alpha =0.50$ were found to be 0.67\% and 0.49\% respectively. The respective percentage errors of 1.97\% and 1.62\% for fractional parameters of $\beta =1,\alpha =0.97$ and $\beta =1,\alpha =0.50$ were obtained for charmonium meson. The results indicate that the potential curves coupled with the fractional parameters account for the short-range gluon exchange between the quark-antiquark interactions and the linear confinement phenomena which is associated with the quantum chromo-dynamic and phenomenological potential models in particle and high-energy physics.

Study of charm and beauty mass spectra, semileptonic decays of $$B_{(s,c)}$$ and $${B_c} \rightarrow J/\psi ({\eta _c}) + P(V)$$ in a phenomenological potential model

Study of charm and beauty mass spectra, semileptonic decays of $$B_{(s,c)}$$ and $${B_c} \rightarrow J/\psi ({\eta _c}) + P(V)$$ in a phenomenological potential model

Static properties and semileptonic transitions of lowest-lying double heavy baryons* *Supported by Kosar University of Bojnord (Grant No. 0011191444)

The static properties and semileptonic decays of ground-state doubly heavy baryons are studied in the framework of a non-relativistic quark model. Using a phenomenological potential model, we calculate the ground-state masses and magnetic moments of doubly heavy Ω and Ξ baryons. In the heavy quark limit, we introduce a simple form of the universal Isgur-Wise function used as the transition form factor and then investigate the exclusive semileptonic decay widths and branching fractions for baryon transitions. Our obtained results are in agreement with other theoretical predictions.

A finite element model of the embryonic zebrafish heart electrophysiology

Background and objectiveIn the last 30 years, a growing interest has involved the study of zebrafish thanks to its physiological characteristics similar to those of humans. The aim of the following work is to create an electrophysiological computational model of the zebrafish heart and lay the foundation for the development of an in-silico model of the zebrafish heart that will allow to study the correlation between pathologies and drug administration with the main electrophysiological parameters as the ECG signal. MethodsThe model considers a whole body and the two chambers of three days post fertilization (3 dpf) zebrafish. A four-variable phenomenological action potential model describes the action potential of different heart regions. Tissue conductivity was calibrated to reproduce the experimentally described activation sequence. ResultsThe model is able to correctly reproduce the activation sequence and times found in literature, with activation of the atrium and ventricle that correspond to 36 and 59 ms, respectively, and a delay of 14 ms caused by the presence of the atrioventricular band (AV band). Moreover, the obtained in-silico ECG reflects the main characteristics of the zebrafish ECG in good agreement with experimental records, a P-wave with a duration of approximately the total atrial activation, followed by a QRS complex of approximately 109 ms corresponding to ventricle activation. ConclusionsThe model allows the assessment of the main electrophysiological parameters in terms of activation sequence and timing, reproducing monopolar and bipolar ECG signals in line with experimental data. Coupling the proposed model with an electrophysiological detailed action potential model of zebrafish will represent a significant breakthrough toward the development of an in-silico zebrafish heart.

Gluons, light and heavy quarks in the instanton vacuum

In this paper, we put our focus towards describing the nonperturbative effects in the properties of hadrons made from the light-heavy and the heavy–heavy quarks in the framework of Instanton Liquid Model (ILM) of QCD vacuum. The main features of ILM and its applicability in the heavy quark sector are briefly discussed. The properties of gluonic systems, the light and heavy quark correlators in the instanton background are also analyzed. We demonstrate that the consideration of both, perturbative and nonperturbative, gluon effects in the instanton background for a single heavy quark leads to the mass shift due to the direct-instanton nonperturbative and ILM modified perturbative contributions, respectively. For the interacting heavy quark and heavy anti-quark, the potential consists of the direct instanton-induced part and the one-gluon exchange (OGE) perturbative part. OGE interactions are screened at large distances due to the nonperturbative dynamics. The estimation of instanton contributions in the phenomenological Cornell-type potential model is presented. In relation to the experimental data, the charmonium properties, the role of instanton effects in their spectra and transitions are discussed. The main features of heavy-light quark systems in the instanton generated background are also discussed. As an example, we consider the process of pion emissions by the exited heavy quarkonium. We show that there is a sizable correction ([Formula: see text]) to the dipole approximation for the process [Formula: see text].

Decay properties of beauty and charm mesons within Isgur–Wise function formalism

We investigate the decay properties of some beauty and charm mesons with a phenomenological potential model. First, we consider the nonrelativistic Hamiltonian of the mesonic system with Coulomb plus exponential terms and study the wave function and the energy of the system using the variational approach. Thereby, we compute the masses, the decay constants, the leptonic branching fractions of heavy–light mesons and the mixing mass parameter $$\Delta {m_{{B_q}}}$$ . We study the radiative leptonic decay widths of $${D_s} \rightarrow \gamma \ell {{\bar{\nu }}} $$ , $${D^ - } \rightarrow \gamma \ell {{\bar{\nu }}} $$ and the semileptonic decay widths of $${{{\bar{B}}}_{(s)}} \rightarrow {D_{(s)}}\ell {{\bar{\nu }}} $$ and $${{{\bar{B}}}_{(s)}} \rightarrow D_{(s)}^*\ell {{\bar{\nu }}} $$ . Using Isgur–Wise function, we calculate the branching ratios of $$B \rightarrow {D^{(*)}}\pi $$ and two-body nonleptonic decay of $$D \rightarrow K\pi $$ . Our results are consistent with other theoretical models and the experimental results.

Mass and decay properties of double heavy baryons with a phenomenological potential model

We consider baryons in a nonrelativistic quark model, find the wave function and masses of the baryons with two heavy quarks including Xi _{bc}(bcu), Xi _{cc}(ccu), Xi _{bb}(bbu), Omega _{bb}(bbs), Omega _{bc}(bcs) and {Omega _{cc}}(ccs). We calculate magnetic moments of these baryons. Using transition magnetic moments, we obtain the radiative decay widths for double heavy baryons. Then we calculate some of the semileptonic decay widths of these baryons. Our results are compared with other theoretical predictions.

Investigation of spatial manifestation of α clusters in 16O via α-transfer reactions

Recently, we have determined surface distributions of α clusters in the ground state of Ne20 from α-transfer cross sections, without investigating the properties of its excited states. In this paper we extend our comprehension of α-cluster structures in excited states of nuclei through reaction studies. In particular we focus on O16, for which attention has been paid to advances of structure theory and assignment regarding 4+-resonance states. We study the surface manifestation of the α-cluster states in both the ground and excited states of O16 from the analysis of the α-transfer reaction C12(Li6,d)16O. The α-transfer reaction is described by the distorted-wave Born approximation. We test two microscopic wave functions as an input of reaction calculations. Then a phenomenological potential model is introduced to clarify the correspondence between cluster-wave functions and transfer-cross sections. Surface peaks of the α-wave function of O16(0+) are sensitively probed by transfer-cross sections at forward angles, while it remains unclear how we trace the surface behavior of O16(4+) from the cross sections. From inspection of the cross sections at forward angles, we are able to specify that the α-cluster structure in the 01+ and 02+ states prominently manifests itself at the radii ∼4 and ∼4.5 fm, respectively. It is remarkable that the 41+ state has the C12+α-cluster component with the surface peak at the radius ∼4 or outer, whereas the C12+α-cluster component in the 42+ state is found not to be dominant. The 42+ state is difficult to be interpreted by a simple potential model assuming the C12+α configuration only.

Radiative transitions and the mixing parameters of the D meson

Spectroscopic parameters of heavy-light flavoured D meson are obtained within the framework of phenomenological quark-antiquark potential (Coulomb plus linear confinement) model using the Gaussian wave function. We incorporated (1/m) corrections to the potential energy term and relativistic corrections to the kinetic energy term of the hamiltonian. We obtain the radiative (electric and magnetic) transitions and the mixing parameters of the DâĹŠ oscillation. The results are compared with various experimental measurement as well as other theoretical predictions.

Evaluation of SF6-alternative gas C5-PFK based on arc extinguishing performance and electric strength

C5-PFK (C5-perfluoroketone, C5F10O) is under wide consideration as an environmentally-friendly alternative gas to SF6 in high-voltage applications, because of its superior insulation performance. The aim of this work is to study theoretically the arc extinguishing performance and electric strength of C5-PFK.The arc extinguishing performance of C5-PFK was evaluated by analyzing and comparing the thermophysical properties of C5-PFK, SF6, CF4, CO2 and N2 plasmas. It was difficult to obtain the species formed in C5-PFK plasmas because of the complex C5-PFK molecular decomposition process. In this work, the decomposition process of C5-PFK and the related species were analyzed by the bond energy analysis method. For the species for which parameters such as the partition function and the enthalpy of formation were not available, computational chemistry methods were used to obtain the required data. The collision integrals were calculated using the phenomenological potential model. Using these results, the local thermodynamic equilibrium composition at temperatures from 300 to 30 000 K at 1–10 atm of pure C5-PFK was calculated by the method of minimization of the Gibbs free energy, and the corresponding transport coefficients were calculated by Chapman–Enskog method. Through the comparison of the thermophysical properties, it was found that C5-PFK had similar characteristics to SF6, with large peaks in specific heat below 4500 K, indicating potentially good thermal interruption capability. However, the specific heat peak at 7000 K corresponding to CO decomposition may detract from the thermal interruption capability. Specific heat peaks at higher temperatures are associated with the breaking of double or triple bonds, and should be avoided if possible in the new alternative gases.The electric strength of C5-PFK was assessed using the molecular electrostatic potential, which can be accurately calculated or measured, and gives strong insights into important characteristics of the molecule. Based on the analysis of the molecular surface electrostatic potential and electric strength of C5-PFK, SF6, CF4, CO2, and N2, it is found that the positive potential area of the molecular surface has a strong correlation with the electric strength and is expected to be one of the predictors of electric strength. To verify this phenomenon, 36 kinds of particles were used for the correlation analysis. The correlation coefficient between the positive potential area and electric strength is up to 0.9 which means strong correlation.

A parallel interaction potential approach coupled with the immersed boundary method for fully resolved simulations of deformable interfaces and membranes

In this paper we show and discuss how the deformation dynamics of closed liquid–liquid interfaces (for example drops and bubbles) can be replicated with use of a phenomenological interaction potential model. This new approach to simulate liquid–liquid interfaces is based on the fundamental principle of minimum potential energy where the total potential energy depends on the extent of deformation of a spring network distributed on the surface of the immersed drop or bubble. Simulating liquid–liquid interfaces using this model require computing ad-hoc elastic constants which is done through a reverse-engineered approach. The results from our simulations agree very well with previous studies on the deformation of drops in standard flow configurations such as a deforming drop in a shear flow or cross flow. The interaction potential model is highly versatile, computationally efficient and can be easily incorporated into generic single phase fluid solvers to also simulate complex fluid–structure interaction problems. This is shown by simulating flow in the left ventricle of the heart with mechanical and natural mitral valves where the imposed flow, motion of ventricle and valves dynamically govern the behaviour of each other. Results from these simulations are compared with ad-hoc in-house experimental measurements. Finally, we present a simple and easy to implement parallelisation scheme, as high performance computing is unavoidable when studying large scale problems involving several thousands of simultaneously deforming bodies in highly turbulent flows.

Excited state mass spectra, decay properties and Regge trajectories of charm and charm-strange mesons**Supported by Department of Science of Technology, India under SERB fast track scheme SR/FTP/PS-152/2012 and also to SVNIT (Institute Research Grant (Dean (R&C)/1488/2013-14))

The framework of a phenomenological quark-antiquark potential (Coulomb plus linear confinement) model with a Gaussian wave function is used for detailed study of masses of the ground, orbitally and radially excited states of heavy-light Qq̅, (Q=c,q=u/d,s) mesons. We incorporate a correction to the potential energy term and relativistic corrections to the kinetic energy term of the Hamiltonian. The spin-hyperfine, spin-orbit and tensor interactions incorporating the effect of mixing are employed to obtain the pseudoscalar, vector, radially and orbitally excited state meson masses. The Regge trajectories in the (J,M2) and (nr,M2) planes for heavy-light mesons are investigated with their corresponding parameters. Leptonic and radiative leptonic decay widths and corresponding branching ratios are computed. The mixing parameters are also estimated. Our predictions are in good agreement with experimental results as well as lattice and other theoretical models.

Probing surface distributions ofαclusters inNe20viaα-transferreaction

Direct evidence of the $\alpha$-cluster manifestation in bound states has not been obtained yet, although a number of experimental studies were carried out to extract the information of the clustering. In particular in conventional analyses of $\alpha$-transfer reactions, there exist a few significant problems on reaction models, which are insufficient to qualitatively discuss the cluster structure. We aim to verify the development of the $\alpha$-cluster structure from observables. As the first application, we plan to extract the spatial information of the cluster structure of the $^{20}$Ne nucleus in its ground state through the cross section of the $\alpha$-transfer reaction $^{16}$O($^6$Li,~$d$)$^{20}$Ne. For the analysis of the transfer reaction, we work with the coupled-channel Born approximation (CCBA) approach, in which the breakup effect of $^6$Li is explicitly taken into account by means of the continuum-discretized coupled-channel method based on the three-body $\alpha + d + {}^{16}$O model. The two methods are adopted to calculate the overlap function between $^{20}$Ne and $\alpha + {}^{16}$O; one is the microscopic cluster model (MCM) with the generator coordinate method, and the other is the phenomenological two-body potential model (PM). We show that the CCBA calculation with the MCM wave function gives a significant improvement of the theoretical result on the angular distribution of the transfer cross section, which is consistent with the experimental data. Employing the PM, it is discussed which region of the cluster wave function is probed on the transfer cross section. It is found that the surface region of the cluster wave function is sensitive to the cross section. The present work is situated as the first step in obtaining important information to systematically investigate the cluster structure.

Spectroscopic properties of the B meson

Investigation of the B(b ¯ q); q = u, d meson properties is carried out using vari- ational method within phenomenological quark antiquark potential(coulomb plus power) model using the Gaussian wave function. O (1/m) correction to the potential energy term and relativistic corrections to the kinetic energy term of the hamiltonian are incorporated. Spin-orbit, spin-spin and tensor interactions are employed to obtain the mass spectra. Various other properties such as the decay constants, e1 and m1 transitions are also ob- tained

Study of various spectroscopic properties of theDsmeson

Spectroscopic parameters of the Ds (cs̄) meson are obtained using phenomenological quark antiquark potential(coulomb plus power) model consisting of O(1/m) correction to the potential. Within Variational scheme Gaussian wave function is employed with a hamiltonian incorporating kinematic relativistic corrections to obtain various properties such as the mass spectra, decay constants, electromagnetic transitions. The results are compared with various experimental measurement as well as other theoretical predictions.

Spectra and decay rates ofbb̄meson using Gaussian wave function

Using the Gaussian wave function mass spectra and decay rates of b¯ b me- son are investigated in the framework of phenomenological quark anti-quark potential (coulomb plus power) model consisting of relativistic corrections to the kinetic energy term. The spin-spin, spin-orbit and tensor interactions are employed to obtain the pseu- doscalar and vector meson masses. The decay constantsfP/Vare computed using the wave function at the origin. The di-gamma and di-leptonic decays of the b¯ b meson are investigated using Van-Rayan Weisskopf formula as well as in the NRQCD formalism.

Spectroscopic properties of the B meson

Investigation of the B(bq̄); q = u, d meson properties is carried out using variational method within phenomenological quark antiquark potential(coulomb plus power) model using the Gaussian wave function. O(1/m) correction to the potential energy term and relativistic corrections to the kinetic energy term of the hamiltonian are incorporated. Spin-orbit, spin-spin and tensor interactions are employed to obtain the mass spectra. Various other properties such as the decay constants, e1 and m1 transitions are also obtained