JournalTOCs

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

Citation Impact (citeScore): 2
Number of Followers: 23

This is an Open Access Journal

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

[339 journals]

Generalising Holographic Superconductors
- Abstract: In this paper we propose a generalised holographic framework to describe superconductors. We first unify the description of s-, p-, and d-wave superconductors in a way that can be easily promoted to higher spin. Using a semianalytical procedure to compute the superconductor properties, we are able to further generalise the geometric description of the hologram beyond the AdS-Schwarzschild Black Hole paradigm and propose a set of higher-dimensional metrics which exhibit the same universal behaviour. We then apply this generalised description to study the properties of the condensate and the scaling of the critical temperature with the parameters of the higher-dimensional theory, which allows us to reproduce existing results in the literature and extend them to include a possible description of the newly observed f-wave superconducting systems.
  PubDate: Fri, 17 Jun 2022 06:20:05 +000
Model Comparison of the Transverse Momentum Spectra of Charged Hadrons
Produced in Collision at TeV
- Abstract: Transverse momentum, , spectra are of prime importance in order to extract crucial information about the evolution dynamics of the system of particles produced in the collider experiments. In this work, the transverse momentum spectra of charged hadrons produced in collision at TeV have been analyzed using different distribution functions in order to gain strong insight into the information that can be extracted from the spectra. We have also discussed the applicability of the unified statistical framework on the spectra of charged hadron at TeV
  PubDate: Tue, 14 Jun 2022 05:05:01 +000
Relaxing the Constraint on Compact Extradimension
- Abstract: In this paper, we study the constraint on brane tension and compactification scale for models with brane fluctuations using the results from the direct search of at 13 TeV LHC, with an integrated luminosity of , in the case for which branon forms the entire cold dark matter. The inclusion of these brane fluctuations suppresses the KK-mode couplings to brane localised matter fields. Unlike the rigid brane scenario, where the compactification scale gets constrained to TeV, here we show that compactification scales as small as TeV are allowed for brane tensions of similar strength.
  PubDate: Wed, 01 Jun 2022 07:20:01 +000
Erratum to “Superstring Backgrounds in String Geometry”
- PubDate: Mon, 30 May 2022 04:05:03 +000
The Analysis of a Proposed Experiment to Measure the Speed of Gravity in
Short Distances
- Abstract: In order to investigate the speed of gravitational signals travelling in air or through a different medium two experiments were designed. One of the experiments contains 2 masses rotating at very high speed and in the other experiment a sapphire bar will vibrate, in both cases they will emit a periodic tidal gravitational signal and one sapphire device that behaves as a detector, which are suspended in vacuum and cooled down to 4.2 K will act as a detector. The vibrational amplitude of the sapphire detector device is measured by an microwave signal with ultralow phase-noise that uses resonance in the whispering gallery modes inside the detector device. Sapphire has a quite high mechanical Q and electrical Q which implies a very narrow detection band thus reducing the detection sensitivity. A new detector shape for the detector device is presented in this work, yielding a detection band of about half of the device vibrational frequency. With the aid of a Finite Element Program the normal mode frequencies of the detector can be calculated with high precision. The results show a similar expected sensitivity between the two experimental setup, but the experiment with the vibration masses is more stable in frequency then it is chosen for the experimental setup to measure the speed of gravity in short distances. Then a more precise analysis is made with this experiment reaching a signal-noise ratio of 10 at a frequency of 5000 Hz.
  PubDate: Wed, 25 May 2022 08:35:01 +000
Linear Stability of Magneto Viscoelastic Walter’s Type with Heat and
Mass Transfer
- Abstract: In this paper, the couple influence of axial magnetic field and the heat and mass transfer on two rotating cylinders of Walter’s viscoelastic fluids by using the potential flow theory of viscoelastic fluid has been investigated. The normal mode method is used to compute the growth rate of disturbance. The influence of gravity is ignored at the interface, while the effect of surface tension is present in the analysis. The effect of the parameters on the stability is studied. It is found that the rotation of the inner cylinder induces stability. Furthermore, the viscoelastic ratio of fluids has a stabilizing influence. The heat and mass transfer, magnetic permeability ratio, and Ohnesorge number have a stabilized influence, while viscosity ratio of fluids, density ratio of fluids, and axial magnetic field have destabilizing influence on the considered system.
  PubDate: Mon, 23 May 2022 08:35:03 +000
Density Perturbation and Cosmological Evolution in the Presence of
Magnetic Field in Gravity Models
- Abstract: In this paper, we have investigated the density perturbations and cosmological evolution in the FLRW universe in the presence of a cosmic magnetic field, which may be assumed to mimic primordial magnetic fields. Such magnetic fields have sufficient strength to influence galaxy formation and cluster dynamics, thereby leaving an imprint on the CMB anisotropies. We have considered the FLRW universe as a representative of the isotropic cosmological model in the covariant formalism for gravity. The propagation equations have been determined and analyzed, where we have assumed that the magnetic field is aligned uniformly along the -direction, resulting in a diagonal shear tensor. Subsequently, the density perturbation evolution equations have been studied, and the results have been interpreted. We have also indicated how these results change in the general relativistic case and briefly mentioned the expected change in higher-order gravity theories.
  PubDate: Mon, 23 May 2022 08:35:02 +000
Affine Connection Representation of Gauge Fields
- Abstract: There are two ways to unify gravitational field and gauge field. One is to represent gravitational field as principal bundle connection, and the other is to represent gauge field as affine connection. Poincaré gauge theory and metric-affine gauge theory adopt the first approach. This paper adopts the second. In this approach, (i) gauge field and gravitational field can both be represented by affine connection; they can be described by a unified spatial frame. (ii) Time can be regarded as the total metric with respect to all dimensions of internal coordinate space and external coordinate space. On-shell can be regarded as gradient direction. Quantum theory can be regarded as a geometric theory of distribution of gradient directions. Hence, gauge theory, gravitational theory, and quantum theory all reflect intrinsic geometric properties of manifold. (iii) Coupling constants, chiral asymmetry, PMNS mixing, and CKM mixing arise spontaneously as geometric properties in affine connection representation, so they are not necessary to be regarded as direct postulates in the Lagrangian anymore. (iv) The unification theory of gauge fields that are represented by affine connection can avoid the problem that a proton decays into a lepton in theories such as . (v) There exists a geometric interpretation to the color confinement of quarks. In the affine connection representation, we can get better interpretations to the above physical properties; therefore, to represent gauge fields by affine connection is probably a necessary step towards the ultimate theory of physics.
  PubDate: Tue, 17 May 2022 16:05:01 +000
Search for the Charmed Baryonium and Dibaryon Structures via the QCD Sum
Rules
- Abstract: In the present work, we construct eight six-quark currents to study the baryonium and dibaryon states via the QCD sum rules. For either baryonium or dibaryon states, we construct four currents with the and . Except the current of , we find the Borel windows for the other seven. There are two possible molecular states or compact six-quark states with the and . The results of the current of show a possible molecular state with 20 MeV binding energy. We find two baryonium resonances states with the and two dibaryon resonances states with the , respectively. Pole residues of the seven states are also calculated.
  PubDate: Thu, 28 Apr 2022 16:05:01 +000
The Asymmetry of the Cosmic Microwave Background Radiation as Signature of
Local Lorentz Invariance Violation
- Abstract: A difference in electric potential in a static conductor inside a static magnetic field and an anisotropic and asymmetric distribution of neutrons emitted in nuclear reactions induced by ultrasound are assumed as marks of local Lorentz invariance (LLI) violation. The asymmetry of the two experiments is related to the asymmetry of the Cosmic Microwave Background Radiation (CMBR). As common directions of asymmetry are found in these three cases, a fundamental asymmetry of the interactions is suggested which can also shed new light on the question of symmetry breaking in the history of the Universe.
  PubDate: Fri, 22 Apr 2022 08:35:03 +000
Inflationary Universe from Anomaly-Free -Gravity
- Abstract: By adding a three-dimensional manifold to an eleven-dimensional manifold in supergravity, we obtain the action of -gravity and find that it is anomaly-free. We calculate the scale factor of the inflationary universe in this model and observe that it is related to the slow-roll parameters. The tensor-scalar ratio is in good agreement with experimental data.
  PubDate: Tue, 29 Mar 2022 11:35:01 +000
Electron Number Density and Coherence Length of Boson-Fermion Pair in HTSC
- Abstract: A Bose-Einstein Condensate (BEC) of a nonzero momentum Cooper pair constitutes a composite boson or simply a boson. Previously, it has been shown that the quantum coherence of the two-component BEC (boson and fermion condensates) is controlled by plasmons where of plasmon energy mediates the charge pairing but most of the plasmon energy is used to overcome the modes that compete against superconductivity such as phonons, charge density waves, antiferromagnetism, and damping effects. The dependence of plasmon frequency on the material of a superconductor reveals that modes within a specific range of frequency enhance superconductivity and therefore affect the critical temperature of a particular superconducting material. Against this background, we study the effect on doping on boson-fermion pairing energy and hence the critical temperature. While most hole doping agents are atoms lighter than copper, many of the electron doping agents are materials heavier than copper. This property defines the doping effect on the plasma frequency. Heavier dopants lower the critical temperature while lighter dopants increase the critical temperature of a superconductor. The number density of electrons is also found to be proportional to the square of critical temperature while the size of a boson-fermion pair condensate (BFPC) is proportional to . The size of a BFPC particle is less than boson-fermion (BF) coherence length by almost an order.
  PubDate: Tue, 29 Mar 2022 08:50:04 +000
The Nonsymmetric Flavor Transition Matrix and the Apparent P Violation
- Abstract: The leptonic mixing parameters of high precision and the next-generation neutrino telescopes make it possible to test new physics in the flavor transition of the high-energy astrophysical neutrinos (HAN). We introduce a nonsymmetric matrix to modify the predictions of the standard flavor transition matrix. It is constructed with the mixing matrix in vacuum and that at the source of the HAN. The mismatch of the mixing matrices results in the new expectation of the flavor ratio of the HAN at Earth. It also leads to a secondary effect called the apparent P violation (APV). The quantitative analyses of the new effects are performed with a moderate setup of the parameters at the source of the HAN. The correlations between the mixing parameters and the new predictions are shown. From the correlations, the dominant parameters determining the new-physics effects are identified.
  PubDate: Sat, 12 Mar 2022 06:20:01 +000
Baryonic Meson Decays
- Abstract: We review the two- and three-body baryonic decays with the dibaryon () as the final states. Accordingly, we summarize the experimental data of the branching fractions, angular asymmetries, and asymmetries. Using the -boson annihilation (exchange) mechanism, the branching fractions of are shown to be interpretable. In the approach of perturbative QCD counting rules, we study the three-body decay channels. In particular, we review the asymmetries of , which are promising to be measured by the LHCb and Belle II experiments. Finally, we remark the theoretical challenges in interpreting and .
  PubDate: Fri, 11 Mar 2022 14:20:02 +000
A Short Theoretical Review of Charmonium Production
- Abstract: In this paper, we review the current status of the phenomenological study of quarkonium production in high-energy collisions. After a brief introduction of several important models and effective field theories for quarkonium production, we discuss the comparisons between theoretical predictions and experimental measurements.
  PubDate: Mon, 07 Mar 2022 14:20:01 +000
Approximate Solutions, Thermal Properties, and Superstatistics Solutions
to Schrödinger Equation
- Abstract: In this work, we apply the parametric Nikiforov-Uvarov method to obtain eigensolutions and total normalized wave function of Schrödinger equation expressed in terms of Jacobi polynomial using Coulomb plus Screened Exponential Hyperbolic Potential (CPSEHP), where we obtained the probability density plots for the proposed potential for various orbital angular quantum number, as well as some special cases (Hellmann and Yukawa potential). The proposed potential is best suitable for smaller values of the screening parameter . The resulting energy eigenvalue is presented in a close form and extended to study thermal properties and superstatistics expressed in terms of partition function and other thermodynamic properties such as vibrational mean energy , vibrational specific heat capacity , vibrational entropy , and vibrational free energy . Using the resulting energy equation and with the help of Matlab software, the numerical bound state solutions were obtained for various values of the screening parameter () as well as different expectation values via Hellmann-Feynman Theorem (HFT). The trend of the partition function and other thermodynamic properties obtained for both thermal properties and superstatistics were in excellent agreement with the existing literatures. Due to the analytical mathematical complexities, the superstatistics and thermal properties were evaluated using Mathematica 10.0 version software. The proposed potential model reduces to Hellmann potential, Yukawa potential, Screened Hyperbolic potential, and Coulomb potential as special cases.
  PubDate: Mon, 07 Mar 2022 09:20:02 +000
Hadronic Molecule Interpretation of and Its Beauty Partners
- Abstract: Motivated by the latest discovery of a new tetraquark with two charm quarks and two light antiquarks by LHCb Collaboration, we investigated the hadronic molecule interpretation of . By calculation, the mass and the decay width of this new structure can be understood in one-meson exchange potential model. The binding energies for these hadronic molecules with are around 1 MeV. Besides, we also studied the possible beauty partners of hadronic molecule , which may be feasible in future LHCb experiments.
  PubDate: Fri, 04 Mar 2022 14:05:01 +000
Multisource Thermal Model Describing Transverse Momentum Spectra of
Final-State Particles in High-Energy Collisions
- Abstract: In this minireview article, the transverse momentum spectra of final-state particles produced in high-energy hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions described by the multisource thermal model at the quark or parton level are summarized. In the model, the participant or contributor quarks or partons are considered to contribute together to the transverse momentum distribution of final-state particles with different modes of contributions. The concrete mode of contribution is generally determined by the difference of azimuthal angles of contributor partons in their emissions.
  PubDate: Thu, 03 Mar 2022 12:05:01 +000
On Lorentz Invariant Complex Scalar Fields
- Abstract: We obtain a Lorentz covariant wave equation whose complex wave function transforms under a Lorentz boost according to the following rule, . We show that the spacetime-dependent phase is the most natural relativistic extension of the phase associated with the transformation rule for the nonrelativistic Schrödinger wave function when it is subjected to a Galilean transformation. We then generalize the previous analysis by postulating that transforms according to the above rule under proper Lorentz transformations (boosts or spatial rotations). This is the most general transformation rule compatible with a Lorentz invariant physical theory whose observables are bilinear functions of the field . We use the previous wave equations to describe several physical systems. In particular, we solve the bound state and scattering problems of two particles which interact both electromagnetically and gravitationally (static electromagnetic and gravitational fields). The former interaction is modeled via the minimal coupling prescription while the latter enters via an external potential. We also formulate logically consistent classical and quantum field theories associated with these Lorentz covariant wave equations. We show that it is possible to make those theories equivalent to the Klein-Gordon theory whenever we have self-interacting terms that do not break their Lorentz invariance or if we introduce electromagnetic interactions via the minimal coupling prescription. For interactions that break Lorentz invariance, we show that the present theories imply that particles and antiparticles behave differently at decaying processes, with the latter being more unstable. This suggests a possible connection between Lorentz invariance-breaking interactions and the matter-antimatter asymmetry problem.
  PubDate: Mon, 28 Feb 2022 14:50:01 +000
Hamiltonian and Lagrangian BRST Quantization in Riemann Manifold
- Abstract: The BRST quantization of particle motion on the hypersurface embedded in Euclidean space is carried out both in Hamiltonian and Lagrangian formalism. Using Batalin-Fradkin-Fradkina-Tyutin (BFFT) method, the second class constraints obtained using Hamiltonian analysis are converted into first class constraints. Then using BFV analysis the BRST symmetry is constructed. We have given a simple example of these kind of system. In the end we have discussed Batalin-Vilkovisky formalism in the context of this (BFFT modified) system.
  PubDate: Sun, 27 Feb 2022 13:35:02 +000
Hunting for Direct CP Violation in
- Abstract: In perturbative QCD approach, based on the first order of isospin symmetry breaking, we study the direct violation in the decay of . An interesting mechanism is applied to enlarge the violating asymmetry involving the charge symmetry breaking between and . We find that the violation is large by the mixing mechanism when the invariant masses of the pairs are in the vicinity of the resonance. For the decay process of , the maximum violation can reach . Furthermore, taking mixing into account, we calculate the branching ratio for . We also discuss the possibility of observing the predicted violation asymmetry at the LHC.
  PubDate: Wed, 23 Feb 2022 12:50:02 +000
Calculated Event Rates for Axion Detection via Atomic and Nuclear
Processes
- Abstract: The possibility of detection of 5.5 MeV and 14.4 keV solar axions by observing axion-induced nuclear and atomic transitions is investigated. The presence of nuclear transitions between spin orbit partners can be manifested by the subsequent deexcitation via gamma ray emissions. The transition rates can also be studied in the context of radiative axion absorption by a nucleus. The elementary interaction is obtained in the context of the axion-quark couplings predicted by existing axion models. Then, these couplings will be transformed to the nucleon level utilizing reasonable existing models, which lead to effective transition operators. Using these operators, we calculate the needed nuclear matrix elements employing wave functions obtained in the context of the nuclear shell model. With these ingredients, we discuss possibilities of experimental observation of the axion-induced nuclear gamma rays. In the second part, we will examine the axion-induced production of X-rays (axion-photon conversion) or ionization from deeply bound electron orbits. In this case, the axion electron coupling is predicted by existing axion models; no renormalization is needed. The experimental signal is the observation of directly produced electrons and/or the emission of hard X-rays and Auger electrons, following the deexcitation of the final atom. Critical discussion is made on the experimental feasibility of detecting the solar axions by using multiton scale NaI detectors.
  PubDate: Tue, 22 Feb 2022 12:20:01 +000
Charmless Quasi-Two-Body Decays in Perturbative QCD Approach: Taking as
Examples
- Abstract: Three-body decays not only significantly broaden the study of meson decay mechanisms but also provide information of resonant particles. Because of complicate dynamics, it is very hard for us to study the whole phase space in a specific approach. In this review, we take decays as examples and show the application of the perturbative QCD (PQCD) approach in studying the quasi-two-body decays, where two particles move collinearly with large energy and the bachelor one recoils back. To describe the dynamics of two collinear particles, the ,, and -wave functions of kaon-pair with different waves are introduced. By keeping the transverse momenta, all possible diagrams including the hard spectator diagrams and annihilation ones can be calculated in PQCD approach. Most results are well consistent with the current measurements from BaBar, Belle, and LHCb experiments. Moreover, under the narrow-width approximation, we can extract the branching fractions of the two-body decays involving the resonant states and also predict the branching fractions of the corresponding quasi-two-body decays . All predictions are expected to be tested in the ongoing LHCb and Belle-II experiments.
  PubDate: Tue, 22 Feb 2022 12:20:01 +000
Form Factors with the -Meson Light-Cone Sum Rules
- Abstract: In this review, we discuss the calculation of the form factors within the framework of the light-cone sum rules with the light-cone distribution amplitudes of the -meson. A detailed introduction to the definition, scale evolution, and phenomenological models of the -meson distribution amplitudes is presented. We show two equivalent approaches of calculating the next-to-leading order QCD corrections to the sum rules for the form factors, i.e., the method of regions and the step-by-step matching in the soft-collinear effective theory. The power suppressed corrections to the form factors especially the contributions from the higher-twist -meson distribution amplitudes are displayed. We also present numerical results of the form factors including both the QCD and the power corrections, and phenomenological applications of the predicted form factors such as the determination of the CKM matrix element .
  PubDate: Tue, 22 Feb 2022 11:05:01 +000
Thermal Freeze-Out Parameters and Pseudoentropy from Charged Hadron
Spectra in High-Energy Collisions
- Abstract: We collected the transverse momentum (mass) spectra of charged hadrons (,,,,, and ) produced in collisions over a center-of-mass energy range from 2.70 to 200 GeV (per nucleon pair). The modified Tsallis–Pareto-type function (the TP-like function) with average transverse flow velocity is used to describe the contribution of participant or constituent quarks to transverse momentum of considered hadron. The experimental spectra of and (or and ) are fitted by the convolution of two (or three) TP-like functions due to the fact that two (or three) constituent quarks are regarded as two (or three) energy resources in the formation of considered hadron. From the reasonable fits to the spectra, the thermal freeze-out parameters are extracted, and the pseudoentropy is newly defined and extracted. Some parameters quickly change in the energy range of less than 7.7 GeV, and slowly change in the energy range of greater than 7.7 GeV, indicating the variation of collision mechanism at around 7.7 GeV.
  PubDate: Mon, 21 Feb 2022 12:35:03 +000
Coherent Photoproduction of Low- Charmonium in Peripheral Heavy Ion
Collisions within the Color Dipole Model
- Abstract: We calculate the centrality dependence for coherent photoproduction of very low- at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies within the impact parameter-dependent saturated color dipole model. By using the large equivalent photon fluxes, we present the differential cross-section of very low- produced by coherent photonuclear in peripheral heavy ion collisions. The numerical results demonstrate that our calculation agrees with data in peripheral heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) energies.
  PubDate: Tue, 15 Feb 2022 05:35:01 +000
Tritonlike Molecules of Three Identical Baryons
- Abstract: In nuclear physics, triton and helium-3 nucleus can be understood as three-body hadronic molecules. Analogous to the loosely bound structures for the triton and helium-3 nucleus, whether there is a bound state formed by three hadrons leaves us an open issue. Based on the one-boson exchange model as well as the adoption of the variational approach, we make a comprehensive investigation on the tritonlike systems of three identical baryons ,,, and . We predict that the three-body molecular states for the systems of three identical hadrons of baryon octet are probably existent as long as their two-body subsystems have bound states. The numerical results of this work may be helpful for the theoretical and experimental researches on the trihadron molecules in future.
  PubDate: Mon, 14 Feb 2022 11:05:02 +000
Residual Gauge Invariance in a Massive Lorentz-Violating Extension of QED
- Abstract: We reassess an alternative CPT-odd electrodynamics obtained from a Palatini-like procedure. Starting from a more general situation, we analyze the physical consistency of the model for different values of the parameter introduced in the mass tensor. We show that there is a residual gauge invariance in the model if the local transformation is taken to vary only in the direction of the Lorentz-breaking vector. This residual gauge invariance can be extended to all models whose only source of gauge symmetry breaking is such a mass term.
  PubDate: Sat, 12 Feb 2022 07:20:03 +000
On the Impact of the LHC Run 2 Data on General Composite Higgs Scenarios
- Abstract: We study the impact of Run 2 LHC data on general composite Higgs scenarios, where nonlinear effects, mixing with additional scalars, and new fermionic degrees of freedom could simultaneously contribute to the modification of Higgs properties. We obtain new experimental limits on the scale of compositeness, the mixing with singlets and doublets with the Higgs, and the mass and mixing angle of top-partners. We also show that for scenarios where new fermionic degrees of freedom are involved in electroweak symmetry breaking, there is an interesting interplay among Higgs coupling measurements, boosted Higgs properties, SMEFT global analyses, and direct searches for single and double production of vector-like quarks.
  PubDate: Wed, 09 Feb 2022 08:35:02 +000
Modeling Particle Transport in Astrophysical Outflows and Simulations of
Associated Emissions from Hadronic Microquasar Jets
- Abstract: In this work, after improving the formulation of the model on particle transport within astrophysical plasma outflows and constructing the appropriate algorithms, we test the reliability and effectiveness of our method through numerical simulations on well-studied galactic microquasars as the SS 433 and the Cyg X-1 systems. Then, we concentrate on predictions of the associated emissions, focusing on detectable high-energy neutrinos and -rays originated from the extragalactic M33 X-7 system, which is an X-ray binary discovered in 2006, located in the neighboring galaxy Messier 33, and has not yet been modeled in detail. The particle and radiation energy distributions, produced from magnetized hadronic astrophysical jets in the context of our method, are assumed to originate from decay and scattering processes taking place among the secondary particles created when hot (relativistic) protons of the jet scatter on thermal (cold) ones (p-p interaction mechanism inside the jet). These distributions are computed by solving the system of coupled integrodifferential transport equations of multiparticle processes (reactions chain) following the inelastic proton-proton (p-p) collisions. For the detection of such high-energy neutrinos as well as multiwavelength (radio, X-ray, and gamma-ray) emissions, extremely sensitive space telescopes and other -ray and neutrino detection instruments are in operation or have been designed like the CTA, IceCube, ANTARES, KM3NeT, and IceCube-Gen-2.
  PubDate: Tue, 08 Feb 2022 07:20:02 +000