JournalTOCs

Advances in High Energy Physics
Journal Prestige (SJR): 0.866

Citation Impact (citeScore): 2
Number of Followers: 27

This is an Open Access Journal

Open Access journal
ISSN (Print) 1687-7357 - ISSN (Online) 1687-7365
Published by Hindawi

[340 journals]

Heavy Quarkonium States With Baryonic Chemical Potential
- Abstract: In this work, we have studied the dissociation behavior of 1S and 2S states of quarkonium using quasiparticle approach where the Debye mass depends on baryonic chemical potential. The binding energies of the quarkonium states has been obtained by using quasiparticle Debye mass which further depends on temperature and baryonic chemical potential (). The effect of on the binding energies and the dissociation temperature have been also studied. The binding energy and dissociation temperature of heavy quarkonia decrease as increases. The effect of on the mass spectra of quarkonium states has been studied well.
  PubDate: Wed, 21 May 2025 08:33:29 +000
Pseudoscalar Field as a Possible Candidate for Phantom Field
- Abstract: We demonstrate the existence of a single pseudoscalar (PS) field in the mathematically backed and parity-preserving modifications of the standard Stückelberg formalism (SSF) in the context of the Lagrangian formulation of the (i) two ()-dimensional (2D) massive Abelian 1-form gauge theory, (ii) three ()-dimensional (3D) massive Abelian 2-form gauge theory, and (iii) four ()-dimensional (4D) massive Abelian 3-form gauge theory. This PS field always turns up with the (i) negative kinetic term and (ii) higher order derivative terms. The latter terms are rendered into the well-defined terms due to the imposition of the on-shell condition for the PS field which is derived from the properly gauge-fixed Lagrangian densities for the above theories. These Lagrangian densities incorporate into themselves the (i) PS field with the negative kinetic term and (ii) pure scalar field with the positive kinetic term. However, both these fields satisfy the Klein–Gordon (KG) equation of motion. The PS field (having the negative kinetic term and a well-defined mass) is one of the possible candidates for the “phantom” field which plays a crucial role in the cyclic, bouncing, and self-accelerated cosmological models of the universe. The “exotic” PS field also satisfies one of the criteria for being a possible candidate for dark matter.
  PubDate: Sun, 13 Apr 2025 23:19:44 +000
On the Square Speed of Sound in High-Energy Collisions: Range of Values
and How to Understand It
- Abstract: After reviewing the sound speeds in various forms and conditions of matter, we investigate the sound speed of hadronic matter that has decoupled from the hot and dense system formed during high-energy collisions. We comprehensively consider factors such as energy loss of the incident beam, rapidity shift of leading nucleons, and the Landau hydrodynamic model for hadron production. The sound speed is related to the width or standard deviation of the Gaussian rapidity distribution of hadrons. The extracted square speed of sound lies within a range from 0 to 1/3 in most cases. For scenarios exceeding this limit, we also provide an explanation.
  PubDate: Wed, 12 Mar 2025 03:39:45 +000
Tensor Condensate Accompanied by Chiral Transition in a Strong Magnetic
Field
- Abstract: We investigate tensor condensates and chiral condensates in the ()-flavor Nambu–Jona–Lasinio model at finite temperature and density in the presence of a strong magnetic field. The emergence of the tensor condensate is attributed to the four-fermion interaction. It is shown that a sufficiently large chemical potential is necessary for the occurrence of a phase transition toward tensor condensate. Furthermore, we investigate the correlation between tensor condensate and spin polarization, which accounts for the oscillatory behavior of the spin polarization during the transition from the chiral condensate to tensor condensate phase.
  PubDate: Thu, 06 Mar 2025 02:37:42 +000
Production of Dileptons in Ultraperipheral Heavy-Ion Collisions With
Two-Photon Processes
- Abstract: We study the photoproduction process of dileptons in heavy-ion collision at relativistic heavy-ion collider (RHIC) and large hadron collider (LHC) energies. The equivalent photon approximation, which equates the electromagnetic field of high-energy charged particles to the photon flux, is used to calculate the processes of dilepton production. The numerical results demonstrate that the experimental study of dileptons in ultraperipheral collisions is feasible at RHIC and LHC energies.
  PubDate: Wed, 05 Mar 2025 00:18:20 +000
On Extracting Thermal Parameters and Scenario in High-Energy Collisions
- Abstract: The inconsistent thermal parameters derived from various models in high-energy collisions are examined. A comprehensive literature review suggests model-independent parameters to address these inconsistencies, based on the average transverse momentum and root-mean-square transverse momentum . The relevant parameters include the initial temperature , effective temperature , kinetic freeze-out temperature , and average transverse velocity , where is the average mass of moving particles in the emission source’s rest frame. Alternatively, can be seen as the intercept in the linear relationship between and , while represents the slope between and (with being the rest mass of a specified particle). Our findings show that these four parameters increase in central collisions, within central rapidity regions, at higher energies, and in larger collision systems. As collision energy rises, excitation functions for all four parameters increase rapidly below approximately 7.7 GeV but slowly above this threshold. At energies greater than 39 GeV, fluctuations appear in these trends with only minor changes observed in their growth rates. This work also reveals a mass-dependent multitemperature scenario related to both initial states and kinetic freeze-out processes.
  PubDate: Tue, 04 Mar 2025 07:03:28 +000
-Symmetry in String Geometry Theory
- Abstract: String geometry theory is one of the candidates of nonperturbative formulation of string theory. In this paper, we have shown that dimensionally reduced string geometry theories have what we call -symmetry. In the case of the dimensional reduction in space-like directions, the -symmetry transformation gives the -dual transformation between the Type IIA and IIB perturbative vacua. In the case of the dimensional reduction in the direction of string geometry time , the -symmetry transformation is independent of the -dual transformation and gives a symmetry that cannot be seen in the perturbative string theories.
  PubDate: Wed, 19 Feb 2025 02:36:58 +000
Deviations From Symmetry Using Group on Neutrino Masses and Mixings
- Abstract: The implication of the neutrino mass model based on discrete flavor symmetry, on parameters of neutrino oscillations, CP violation, and effective neutrino masses is studied using the Type I seesaw mechanism. The standard model particle content is extended by adding two additional Higgs doublets, three right-handed neutrinos, and two scalar triplets under symmetry predicting diagonal charged lepton mass matrix. This can generate the desired deviation from symmetry. The resulting neutrino oscillation parameters are well agreed with the latest global fit oscillation data. The sum of the three absolute neutrino mass eigenvalues, (), is found to be consistent with the value given by the latest Planck cosmological data, eV. The model further predicts effective neutrino masses for neutrinoless double beta decay, meV; tritium beta decay, meV; Jarlskog invariant, for CP violation; baryon asymmetry for normal hierarchical case; and also meV, meV, , and for inverted hierarchical case, respectively.
  PubDate: Fri, 29 Nov 2024 11:05:12 +000
-Deformed Glueball Spectrum in AdS/QCD Correspondence
- Abstract: This work presents the application of the -algebra in the glueball spectrum. This algebra is implemented through Jackson’s derivatives in a Schrödinger-like equation resulting from the gravity fluctuations around the braneworld scenario in five dimensions. In our prescription, we consider a four-dimensional AdS4 brane, living in AdS5 bulk, that is also known for describing locally localized gravity via quasizero mode. At the appropriate limit, this background leads to confinement and allows us to find the shape of the -deformed glueball spectrum in the AdS5/QCD4 correspondence. The introduction of the -deformation provides us with a richer glueball spectrum.
  PubDate: Sat, 26 Oct 2024 11:21:49 +000
Study of the Gyro and Divergence Characteristics of Relativistic Charged
Particle Beam Propagation in Earth’s Magnetic Field
- Abstract: Relativistic charged particle beam can be used as a destructive beam weapon in space for debris removal tasks. The trajectories of charged particles are affected by both electric and magnetic forces in the Earth’s magnetic field. In this paper, we firstly analyzed the correlation parameters of the charged particle beam as a weapon when it is propagated in the geomagnetic field. Then, the models were constructed based on COMSOL Multiphysics, and the IGRF model was adopted in the simulation. The gyroradius and the related uncertainty were analyzed by simulation of the charged particle transport in the geomagnetic field at different altitudes. The charged beam spot radius divergency was also simulated. The geomagnetic field can inhibite the diffusion of the electron beam.
  PubDate: Mon, 21 Oct 2024 14:48:59 +000
Hermitian Matrix Diagonalization and Its Symmetry Properties
- Abstract: A Hermitian matrix can be parametrized by a set consisting of its determinant and the eigenvalues of its submatrices. We established a group of equations which connect these variables with the mixing parameters of diagonalization. These equations are simple in structure and manifestly invariant in form under the symmetry operations of dilatation, translation, rephasing, and permutation. When applied to the problem of neutrino oscillation in matter, they produced two new “matter invariants” which are confirmed by available data.
  PubDate: Mon, 30 Sep 2024 12:34:39 +000
Quasinormal Modes of Bardeen Black Hole in 5-Dimensional
Gauss–Bonnet Gravity
- Abstract: This study addressed the scalar field quasinormal ringing behavior of black holes. We investigated scalar field perturbations in Bardeen black hole spacetime in 5-dimensional Einstein–Gauss–Bonnet (EGB) gravity. Using the sixth-order Padé approximation and the finite difference method, we computed the frequency of quasinormal modes (QNMs) in the spacetime background. The calculations demonstrated that the real part of the QNMs increased, whereas the imaginary part decreased with increase in the magnetic charge parameter of the Bardeen black hole for a fixed Gauss–Bonnet parameter . This was also valid when was fixed and increased, where in the real part of the QNMs increased and the absolute value of the imaginary part decreased. However, the change in the latter case was more significant than that in the former; thus, the frequency of eigenvibration of this black hole background under the scalar field perturbation increased and the decay of eigenvibration decreased with increase in or . Moreover, this result shows that the effect of on the intrinsic vibration of this black hole was greater than that of .
  PubDate: Wed, 04 Sep 2024 09:53:00 +000
Higgs Information and NMSSM at the Large Hadron Collider
- Abstract: Information theory has proven to be a worthwhile tool for investigating the implications of the Higgs sector in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) using Higgs information at the Large Hadron Collider (LHC) assessed through the entropy constructed by means of the branching ratios of decay channels of the Higgs boson. The present article focuses on the parameter space of supersymmetric extension with an extra term of singlet in light of various experimental constraints. Our findings show the most preferred values of ,,,,,, neutralino lightest supersymmetric particle (LSP) , lighter chargino , singlino , and gluino to be around 1.93 TeV, 1.78 TeV, −3.62 TeV, 27.5, 0.012, 665.7 GeV, 740 GeV, 790 GeV, 11.24 TeV, and 3.70 TeV, respectively, that is compatible with the relic density of dark matter.
  PubDate: Thu, 25 Jul 2024 14:35:07 +000
Charged Particles Moving around a Spherically Symmetric Dilatonic Black
Hole
- Abstract: For the static spherically symmetric dilatonic black hole described by the Gibbons–Maeda–Garfinkle–Horowitz–Strominger geometry, we analyze the timelike trajectories for electrically charged test particles. Both cases of an electric black hole and a magnetic one are considered. Finally, we are obtaining the solution to the Klein–Gordon equation in terms of Heun confluent functions and the corresponding energy spectrum. A special attention is given to the role of the dilaton parameter.
  PubDate: Mon, 08 Jul 2024 10:49:58 +000
Top Quark Flavor Changing Couplings at a Muon Collider
- Abstract: There is growing interest in the development of a muon collider that would make it possible to produce lepton collisions at energies of several TeV. Among others, there can be significant contributions to electroweak gauge boson, Higgs boson, and top quark physics. In this work, we pay attention to the latter, in particular, effective flavor-changing (FC) top-quark interactions. We discuss the flavor-changing production processes that can be a good probe of the dimension-six top quark four-fermion and fermion-boson operators in the SMEFT. We consider all sixteen operators that can generate flavor-changing top quark couplings. After comparing with the current LHC bounds, we find potential limits three or four orders of magnitude stronger for four-fermion operators. Concerning fermion-boson couplings, for the tensor operators and , we obtain the highest sensitivity. We also observe that the effective approximation (EWA) does not apply with .
  PubDate: Thu, 04 Jul 2024 10:20:36 +000
Statistical Issues on the Neutrino Mass Hierarchy with
- Abstract: The neutrino mass hierarchy determination ( MHD) is one of the main goals of the major current and future neutrino experiments. The statistical analysis usually proceeds from a standard method, a single-dimensional estimator that shows some drawbacks and concerns, together with a debatable strategy. The drawbacks and considerations of the standard method will be explained through the following three main issues. The first issue corresponds to the limited power of the standard method. The estimator provides us with different results when different simulation procedures were used. Regarding the second issue, when and are drawn in a 2D map, their strong positive correlation manifests as a bidimensional variable, instead of a single-dimensional estimator. The overlapping between the distributions of the two hypotheses leads to an experiment sensitivity reduction. The third issue corresponds to the robustness of the standard method. When the JUNO sensitivity is obtained using different procedures, either with as one-dimensional or as two-dimensional estimator, the experimental sensitivity varies with the different values of the atmospheric mass, the input parameter. We computed the oscillation of with the input parameter values, . The MH significance using the standard method, , strongly depends on the values of the parameter . Consequently, the experiment sensitivity depends on the precision of the atmospheric mass. This evaluation of the standard method confirms the drawbacks.
  PubDate: Tue, 14 May 2024 12:50:00 +000
Determination of the Energy Eigenvalues of the Varshni-Hellmann Potential
- Abstract: In this paper, we solve the bound state problem for the Varshni-Hellmann potential via a useful technique. In our technique, we obtain the bound state solution of the Schrödinger equation for the Varshni-Hellmann potential via ansatz method. We obtain the energy eigenvalues and the corresponding eigenfunctions. Also, the behavior of the energy spectra for both the ground and the excited state of the two body systems is illustrated graphically. The similarity of our results to the accurate numerical values is indicative of the efficiency of our technique.
  PubDate: Fri, 10 May 2024 10:35:00 +000
Hint for a Minimal Interaction Length in Annihilation in Total Cross
Section of Center-of-Mass Energies 55-207 GeV
- Abstract: The measurements of the total cross section of the reaction from the VENUS, TOPAS, OPAL, DELPHI, ALEPH, and L3 collaborations, collected between 1989 and 2003, are used to perform a test to validate the current quantum electrodynamics (QED) theory and search for possible deviations with the direct contact term annihilation. By observing a deviation from the QED predictions on the total cross section of the reaction above GeV, a non-QED direct contact term is introduced following the dimension 6 effective theory to explain the deviation. In the non-QED direct contact term, a threshold energy scale is included and explained to the finite interaction length in direct contact term and in consequence the size of the electron involved in the annihilation area. The experimental data of the total cross section is compared to the QED cross section by a test, which gives a best fit of the to be GeV, corresponding to a finite interaction length of (cm). In the direct contact term annihilation, this interaction length is a measure of the size of an electron . By combining all the data results from the mentioned collaborations, we have at least 2 to 3 times more statistics than every single experiment at high region. This induces the best precision on compared to the previous measurements.
  PubDate: Wed, 10 Apr 2024 11:50:00 +000
Dissociation of and Using Dissociation Energy Criteria in -Dimensional
Space
- Abstract: The analytical exact iteration method (AEIM) has been widely used to calculate -dimensional radial Schrodinger equation with medium-modified form of Cornell potential and is generalized to the finite value of magnetic field (eB) with quasiparticle approach in hot quantum chromodynamics (QCD) medium. In -dimensional space, the energy eigenvalues have been calculated for any states (,). These results have been used to study the properties of quarkonium states (i.e, the binding energy and mass spectra, dissociation temperature, and thermodynamical properties in the -dimensional space). We have determined the binding energy of the ground states of quarkonium with magnetic field and dimensionality number. We have also determined the effects of magnetic field and dimensionality number on mass spectra for ground states of quarkonia. But the main result is quite noticeable for the values of dissociation temperature in terms of magnetic field and dimensionality number for ground states of quarkonia after using the criteria of dissociation energy. At last, we have also calculated the thermodynamical properties of QGP (i.e., pressure, energy density, and speed of sound) using the parameter eB with ideal equation of states (EoS). A preprint has previously been published (Solanki et al., 2023).
  PubDate: Mon, 08 Apr 2024 13:35:00 +000
Creation Field Cosmological Model with Variable Cosmological Term () in
Bianchi Type III Space-Time
- Abstract: The paper is devoted to the study of cosmological models with time-varying cosmological term () in the presence of creation field in the framework of Bianchi type III space-time. To obtain deterministic model of the universe, we have assumed , where is the scale factor, for steady state cosmology and creation field, and shear () is proportion to expansion () which leads to , where and are the metric potentials to explain small anisotropic behaviour of the universe and its isotropy. To obtain the results in terms of cosmic time , we have assumed . The model satisfies conservation equations, and creation field increases with time. The present model is free from singularity, has particle horizon, and provides a natural explanation for inflationary scenario and isotropization. Creation field and Einstein field equations are derived using principle of least action and Lagrangian formulation of variable cosmological term. For illustrative purposes, evolutionary behaviour of some cosmological parameters are shown graphically. The other physical aspects like accelerating behaviour of the model are also discussed. Thus, the model represents not only expanding universe but also accelerating which matches with the results of present-day observations.
  PubDate: Fri, 05 Apr 2024 09:50:00 +000
Solving Schrödinger Wave Equation for the Charmonium Spectrum Using
Artificial Neural Networks
- Abstract: In this study, we solved the Schrödinger wave equation by using effective potential in an artificial neural network (ANN) for the mass spectrum of different charmonium states, including ,,, and . The ANN approach provides an efficient, more general, and continuous solution-approximating strategy, thus eliminating the possibility of skipping any region of interest in mass spectroscopy. The close consistency of ANN results with the already-reported results from numerical and theoretical approaches and experimental ones shows the reliability and accuracy of the ANN approach.
  PubDate: Wed, 03 Apr 2024 08:20:00 +000
Extracting Kinetic Freeze-Out Properties in High-Energy Collisions Using a
Multisource Thermal Model
- Abstract: We study the transverse momentum () spectra of neutral pions and identified charged hadrons produced in proton–proton (pp), deuteron–gold (d–Au), and gold–gold (Au–Au) collisions at the center of mass energy GeV. The study is made in the framework of a multisource thermal model used in the partonic level. It is assumed that the contribution to the -value of any hadron comes from two or three partons with an isotropic distribution of the azimuthal angle. The contribution of each parton to the -value of a given hadron is assumed to obey any one of the standard (Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein) distributions with the kinetic freeze-out temperature and average transverse flow velocity. The spectra of the final-state hadrons can be fitted by the superposition of two or three components. The results obtained from our Monte Carlo method are used to fit the experimental results of the PHENIX and STAR Collaborations. The results of the present work serve as a suitable reference baseline for other experiments and simulation studies.
  PubDate: Mon, 25 Mar 2024 13:20:01 +000
Modified Gravity Model and Wormhole Solution
- Abstract: We investigate wormhole solutions using the modified gravity model with viscosity and aim to find a solution for the existence of wormholes mathematically without violating the energy conditions. We show that there is no need to define a wormhole from exotic matter and analyze the equations with numerical analysis to establish weak energy conditions. In the numerical analysis, we found that the appropriate values of the parameters can maintain the weak energy conditions without the need for exotic matter. Adjusting the parameters of the model can increase or decrease the rate of positive energy density or radial and tangential pressures. According to the numerical analysis conducted in this paper, the weak energy conditions are established in the whole space if and or and . The analysis also showed that the supporting matter of the wormhole is near normal matter, indicating that the generalized model with viscosity has an acceptable parameter space to describe a wormhole without the need for exotic matter.
  PubDate: Tue, 12 Mar 2024 08:50:00 +000
Properties and Behaviors of Heavy Quarkonia: Insights through Fractional
Model and Topological Defects
- Abstract: In this study, we investigated the impact of a topological defect () on the properties of heavy quarkonia using the extended Cornell potential. We solved the fractional radial Schrödinger equation (SE) using the extended Nikiforov-Uvarov (ENU) method to obtain the eigenvalues of energy, which allowed us to calculate the masses of charmonium and bottomonium. One significant observation was the splitting between nP and nD states, which attributed to the presence of the topological defect. We discovered that the excited states were divided into components corresponding to , indicating that the gravity field induced by the topological defect interacts with energy levels like the Zeeman effect caused by a magnetic field. Additionally, we derived the wave function and calculated the root-mean radii for charmonium and bottomonium. A comparison with the classical models was performed, resulting in better results being obtained. Furthermore, we investigated the thermodynamic properties of charmonium and bottomonium, determining quantities such as energy, partition function, free energy, mean energy, specific heat, and entropy for P-states. The obtained results were found to be consistent with experimental data and previous works. In conclusion, the fractional model used in this work proved an essential role in understanding the various properties and behaviors of heavy quarkonia in the presence of topological defects.
  PubDate: Sat, 02 Mar 2024 07:50:01 +000
Role of Time-Varying Magnetic Field on QGP Equation of State
- Abstract: The phase diagram of quantum chromodynamics (QCD) and its associated thermodynamic properties of quark-gluon plasma (QGP) are studied in the presence of time-dependent magnetic field. The study plays a pivotal role in the field of cosmology, astrophysics, and heavy-ion collisions. In order to explore the structure of quark-gluon plasma to deal with the dynamics of quarks and gluons, we investigate the equation of state (EoS) not only in the environment of static magnetic field but also in the presence of time-varying magnetic fields. So, for determining the equation of state of QGP at nonzero magnetic fields, we revisited our earlier model where the effect of time-varying magnetic field was not taken into consideration. Using the phenomenological model, some appealing features are noticed depending upon the three different scales: effective mass of quark, temperature, and time-independent and time-dependent magnetic fields. Earlier the effective mass of quark was incorporated in our calculations, and in the current work, it is modified for static and time-varying magnetic fields. Thermodynamic observables including pressure, energy density, and entropy are calculated for a wide range of temperature- and time-dependent as well as time-independent magnetic fields. Finally, we claim that the EoS are highly affected in the presence of a magnetic field. Our results are notable compared to other approaches and found to be advantageous for the measurement of QGP equation of state. These crucial findings with and without time-varying magnetic field could have phenomenological implications in various sectors of high-energy physics.
  PubDate: Mon, 12 Feb 2024 12:20:01 +000
Thick Branes in Horndeski Gravity
- Abstract: We investigate thick brane solutions in the Horndeski gravity. In this setup, we found analytical solutions, applying the first-order formalism to two scalar fields where the first field comes from the nonminimal scalar-tensor coupling and the second is due to the matter contribution sector. With these analytical solutions, we evaluate the symmetric thick brane solutions in Horndeski gravity with four-dimensional geometry. In such a setup, we evaluate the gravity fluctuations to find “almost massless modes,” for any values of the Horndeski parameters. These modes were used to compute the corrections to the Newtonian potential and evaluate the limit four-dimensional gravity.
  PubDate: Fri, 02 Feb 2024 07:35:01 +000

HOME > Browse the 73 Subjects covered by JournalTOCs
Subject	Total Journals