Regge Trajectories Research Articles

Mass spectra of Ξ cc , Ξ bc , Ω cc , and Ω bc baryons in Regge phenomenology

In this article, we study the mass spectra of baryons containing two heavy quarks; charm-charm (cc) and bottom-charm (bc) with a light quark (u, d, s) within the framework of Regge phenomenology. With the assumption of linear Regge trajectories we have derived the relations between slope ratios, intercepts, and baryon masses. Using these relations, the ground state masses of Ξ cc , Ξ bc , Ω cc , and Ω bc baryons are obtained. The values of Regge slopes and Regge intercepts are extracted for these baryons to estimate the excited state masses in both the (J, M 2) and (n, M 2) planes. Our obtained results are compared with the experimental observations where available and other theoretical predictions, which could be a valuable addition to the interpretations of experimentally unknown heavy baryon spectra.

Radially excited (n = 3) charm mesons in heavy quark effective theory

Abstract By exploring heavy quark effective theory we use theoretical available data for bottom mesons to analyze the masses and decays for n = 3 charm mesons. From the predicted masses, we study ground state strong decay modes in terms of couplings. Comparing the decays with available total decay widths, we provide upper bounds on the associated couplings. We also plot Regge trajectories for our predicted data in the (J, M2) and (nr, M2) planes, and estimate higher masses (n = 4) by fixing Regge slopes and intercepts. These Regge trajectories and study of branching ratios are used to clarify the $D_2^{*}(3000)$ state’s JP as the 13F2 state. The results presented may be further confirmed through upcoming experimental information.

Masses, Radii and Regge Trajectories of $$\Sigma _{u}^{-}$$ State Hybrid Charmonium

In this paper, masses, radii and $$E_1$$ radiative transitions of $$\Sigma ^-_u$$ state hybrid charmonium mesons for radial and orbital excitations are calculated by numerically solving the Schrödinger equation with non-relativistic potential model. Results for calculated masses of $$\Sigma ^-_{u}$$ states charmonium hybrid mesons are found to be close to the results obtained through lattice simulations. Calculated masses are used to construct Regge trajectories. It is found that the trajectories are almost linear and parallel.

Spectra and Decay Properties of $$\varLambda _b$$ and $$\varSigma _b$$ Baryons

In this article, we study the radial states as well as orbital states mass spectra of the nonstrange baryons from bottom family utilizing hypercentral Constituent Quark Model(hCQM), a non-relativistic approach by employing screened potential as confining potential with color Coulomb potential. The spin-spin, spin-orbital and tensor interaction are considered for hyperfine splitting calculation. The mass spectra calculated and compared with other theoretical approaches. The Regge trajectories has been plotted in $(J, M^2)$ plane using the calculated mass spectra. Further, the single-pion decay and radiative decay have been described and magnetic moments are determined for the ground state.

Low-Energy Electron Elastic Total Cross Sections for the Large Actinide Atoms Cf, Fm and Md

The rigorous Regge pole method has been used to investigate negative-ion formation in the large actinide atoms Cf, Fm and Md through the elastic total cross sections (TCSs) calculation in the electron impact energy range 0.0 ≤ E ≤ 10.0eV. Ground, metastable and excited negative-ion formation as well as shape resonances (SRs) and Ramsauer-Townsend (R-T) minima are found to characterize generally the TCSs which also exhibit fullerene molecular behavior near threshold through the TCSs of the highest excited states, while maintaining atomic character through the ground state TCSs. Additionally, a polarization-induced metastable TCS with a pronounced SR appears for the first time very close to threshold in the Cf TCSs, having flipped over from a deep R-T minimum near threshold in the Bk TCSs. This behavior manifests the impact of the size effect and the 6d-orbital collapse as well as demonstrates the sensitivity of the R-T minima and the SRs to the electronic structure of these atoms, thereby permitting their first ever use as novel confirmation of Cf as a transitional element in the actinide series. Rigorous and unambiguous ground, metastable and excited anionic states BEs extracted from the TCSs are compared with the existing electron affinities.

Scattering amplitudes in the Regge limit and the soft anomalous dimension through four loops

Using rapidity evolution equations we study two-to-two gauge-theory scattering amplitudes in the Regge limit. We carry out explicit computations at next-to-next-to-leading logarithmic accuracy through four loops and present new results for both infrared-singular and finite contributions to the amplitude. New techniques are devised in order to derive the colour structure stemming from three-Reggeon exchange diagrams in terms of commutators of channel operators, obtaining results that are valid for any gauge group, and apply to scattered particles in any colour representation. We also elucidate the separation between contributions to the Regge cut and Regge pole in the real part of the amplitude to all loop orders. We show that planar contributions due to multiple-Reggeon exchange diagrams can be factorised as a Regge pole along with the single-Reggeon exchange, and when this is done, the singular part of the gluon Regge trajectory is directly determined by the cusp anomalous dimension. We explicitly compute the Regge cut component of the amplitude through four loops and show that it is non-planar. From a different perspective, the new results provide important information on soft singularities in general kinematics beyond the planar limit: by comparing the computed corrections to the general form of the four-loop soft anomalous dimension we derive powerful constraints on its kinematic dependence, opening the way for a bootstrap-based determination.

Towards a theory of bottom-up holographic models for linear Regge trajectories of light mesons

We advance in constructing a bottom-up holographic theory of linear meson Regge trajectories that generalizes and unites into one logical framework various bottom-up holographic approaches proposed in the past and scattered in the literature. The starting point of the theory is a quadratic in fields holographic five-dimensional action in which the Poincaré invariance along the holographic coordinate is violated in the most general way compatible with the linear Regge behavior of the discrete spectrum in four dimensions. It is further demonstrated how different Soft Wall (SW) like holographic models existing in the literature plus some new ones emerge from our general setup. Various interrelations between the emerging models are studied. These models include the known SW models with different sign in the exponential background, the SW models with certain generalized backgrounds, with modified metrics, and No Wall models with 5D mass depending on the holographic coordinate in a simple polynomial way. We argue that this dependence allows to describe the effects caused by the main non-local phenomena of strongly coupled 4D gauge theory, the confinement and chiral symmetry breaking, in terms of a local 5D dual field theory in the AdS space. We provide a detailed comparison of our approach with the Light Front holographic QCD, with the spectroscopic predictions of the dual Veneziano like amplitudes, and with the experimental Regge phenomenology. We apply our general approach to a holographic study of confinement, chiral symmetry breaking, and the pion form factor.

Bottomonium spectroscopy using Coulomb plus linear (Cornell) potential

The Coulomb plus linear (Cornell) potential is used to investigate the mass spectrum of bottomonium. Gaussian wave function is used in position and momentum space to estimate values of potential and kinetic energies, respectively. Based on our calculations, we study newly observed $${\varUpsilon {(10860)}}$$ as an admixture of $$4^{3}S_{1}$$ with $$4^{3}D_{1}$$ and $${\varUpsilon {(10753)}}$$ as an admixture of $$6^{3}S_{1}$$ with $$4^{3}D_{1}$$ ; also, we try to assign $${{\varvec{\Upsilon }}{(11020)}}$$ as a pure $$4^{3}D_{1}$$ bottomonium state. We also study the Regge trajectories in the $$(J,M^{2})$$ and $$(n_r,M^{2})$$ planes to help prove our association. We estimate the pseudoscalar and vector decay constants, the radiative (electric and magnetic dipole) transition rates, and the annihilation decay width for bottomonium states.

Towards a single scale-dependent Pomeron in holographic light-front QCD

The Pomeron Regge trajectory underlies the dynamics dependence of hadronic total cross sections and diffractive reactions at high energies. The physics of the Pomeron is closely related to the gluon distribution function and the gluon gravitational form factor of the target hadron. In this article we examine the scale dependence of the nonperturbative gluon distribution in the nucleon and the pion, which was derived in a previous article [G. F. de T\'eramond, H. G. Dosch, T. Liu, R. S. Sufian, S. J. Brodsky, and A. Deur, Gluon matter distribution in the proton and pion from extended holographic light-front QCD, Phys. Rev. D 104, 114005 (2021)] in the framework of holographic light-front QCD and the Veneziano model. We argue that the QCD evolution of the gluon distribution function $g(x,\ensuremath{\mu})$ to large ${\ensuremath{\mu}}^{2}$ leads to a single scale-dependent Pomeron. The resulting Pomeron trajectory ${\ensuremath{\alpha}}_{P}(t,\ensuremath{\mu})$ not only depends on the momentum transfer squared $t$, but also on the physical scale $\ensuremath{\mu}$ of the amplitude, such as the virtuality ${Q}^{2}$ of the interacting photon in inclusive diffractive electroproduction, thus unifying the soft and the perturbative Pomeron. This can explain not only the ${Q}^{2}$ evolution of the proton structure function ${F}_{2}(x,{Q}^{2})$ at small $x$, but also the observed energy and ${Q}^{2}$ dependence of high energy diffractive processes involving virtual photons up to LHC energies.

Event-by-Event Investigation of the Two-Particle Source Function in Heavy-Ion Collisions with EPOS.

Exploring the shape of the pair-source function for particles such as pions or kaons has been an important goal of heavy-ion physics, and substantial effort has been made in order to understand the underlying physics behind the experimental observations of non-Gaussian behavior. In experiments, since no direct measurement of the source function is possible, quantum-statistical momentum correlations are utilized to gain information about the space-time geometry of the particle emitting source. Event generators, such as EPOS, however, provide direct access to the freeze-out coordinates of final state particles, and thus the source function can be constructed and investigated. The EPOS model is a sophisticated hybrid model where the initial stage evolution of the system is governed by Parton-Based Gribov–Regge theory, and subsequently a hydrodynamic evolution is utilized, followed by hadronization and hadron dynamics. EPOS has already proven to be successful in describing several different experimental observations for systems characterized by baryon chemical potential close to zero, but so far the source shape has not been explored in detail. In this paper we discuss an event-by-event analysis of the two-particle source function in = 200 GeV Au+Au collisions generated by the EPOS model. We find that when utilizing all stages of the model, Lévy-shaped distributions (unlike Gaussian distributions) provide a good description of the source shape in the individual events. Hence it is clear that it is not the event averaging that creates the non-Gaussian features in the pair distributions. Based on this observation, we determine Lévy-parameters of the source as a function of event centrality and particle momentum.

On Asymptotic Regge Trajectories of Heavy Meson Resonances

We performed the analysis of the asymptotic behavior of Regge trajectories of nonstrange and strange mesons and found that thewidth of heavy hadrons for these trajectories cannot linearly depend on their mass. Such a finding clearly demonstrates that a widely spread belief on the linear mass dependence of the resonance width contradicts the linearity of Regge trajectories on theMandelstam variable s. Using the data on masses and widths for ρJ––, ωJ––, aJ++,, and fJ++ mesons with the spin values J ≤ 6 and for K*J mesons with J ≤ 5, we extracted the parameters of the asymptotically linear Regge trajectories predicted by the finite-width model of quark gluon bags. It is shown that the parameters obtained for the data sets B and D are consistent with the cross-over temperaturedetermined by the lattice QCD simulations at the vanishing baryonic density and with the kinetic freeze-out temperature of early hadronizing particles found in relativistic heavy ion collisions at and above the highest SPS energy. Comparing the resonance width of sets B and D evaluated at the masses of Z and W bosons, respectively, we discovered that the calculated width values match that of the gauge bosons. We argue that such matches provide us with indirect, but the first experimental evidence for the compositeness of Z and W bosons. Based on these findings, we assume that Z, W, and Higgs bosons have the Regge trajectories which are similar to the asymptotic trajectories of the studied mesons. The predictions for the masses and widths of the Regge partners of Z and W bosons and for the mass dependence of the widths of Higgs boson Regge partners along with the values for the mass and width of the scalar Higgs mesons are made as well.

Low-mass Diffraction Dissociation at the LHC. Role of the Background

A dual model with a nonlinear proton Regge trajectory in the missing mass (M2X) channel is constructed. A background based on a direct-channel exotic trajectory, developed and applied earlier for the inclusive electron-proton cross section description in the nucleon resonance region, is used. The parameters of the model are determined from the extrapolations to earlier experiments. Predictions for the low-mass (2 < M2X < 8 GeV2) diffraction dissociation cross sections at the LHC energies are given.

AdS/QCD oddball masses and the odderon Regge trajectory from a twist-five operator approach

In this work, we consider a massive gauge boson field in ${\mathrm{AdS}}_{5}$ dual to odd glueball states with twist-5 operator in 4D Minkowski spacetime. Introducing an IR cutoff, we break the conformal symmetry of the boundary theory allowing us to calculate the glueball masses with odd spins using Dirichlet and Neumann boundary conditions. Then, from these masses, we construct the corresponding Regge trajectories associated with the odderon. Our results are compatible with the ones in the literature.

The gluon Regge trajectory at three loops from planar Yang-Mills theory

We compute the three-loop leading-colour corrections to the Yang-Mills Regge trajectory and gluon impact factor. Conjecturing that, in analogy with mathcal{N} = 4 super Yang-Mills (SYM), in a suitable scheme Nc-subleading terms are absent from the three-loop Regge trajectory, we understand our result as the first computation of the pure gauge, or nf = 0, part of the QCD three-loop Regge trajectory. The results are presented both for the bare and renormalised amplitudes and are consistent with predictions from infrared factorisation along with reproducing known results in planar mathcal{N} = 4 SYM through a maximal weight truncation. We also include the dependence on a Regge factorisation scale to facilitate future applications in BFKL theory at next-to-next-to leading logarithmic accuracy.

Regge trajectories for the (2, 0) theories

We investigate the structure of conformal Regge trajectories for the maximally supersymmetric (2, 0) theories in six dimensions. The different conformal multiplets in a single superconformal multiplet must all have similarly-shaped Regge trajectories. We show that these super-descendant trajectories interact in interesting ways, leading to new constraints on their shape. For the four-point function of the stress tensor multiplet supersymmetry also softens the Regge behavior in some channels, and consequently we observe that ‘analyticity in spin’ holds for all spins greater than −3. All the physical operators in this correlator therefore lie on Regge trajectories and we describe an iterative scheme where the Lorentzian inversion formula can be used to bootstrap the four-point function. Some numerical experiments yield promising results, with OPE data approaching the numerical bootstrap results for all theories with rank greater than one.

Spectroscopic Properties of Light Baryon

Hadron Spectroscopy provides a realm to study the internal quark dynamics within the hadrons through phenomenological, theoretical as well as experimental approaches. In the present article, an attempt has been made to exploit the nucleon N resonances using a non-relativistic hypercentral Constituent Quark Model (hCQM). The properties are studied based on the linear nature of confining part of the potential. The 1S-5S, 1P-3P, 1D-2D and 1F states mostly with four star labelled resonances are explored again with the separation of charge states using different constituent quark masses. Also, Regge trajectories for some obtained states are plotted for examining the linear nature.

Изучение наклона дифракционного конуса рассеяния адронов на ядрах

In this paper, we propose a Regge-pole model with a Gaussian potential for studying hadron scattering at high energies. In the diffraction approximation and the consequences arising from the analyticity and unitarity of the scattering amplitude, an expression is obtained for the matrix of the scattering amplitude, for the cross section, and for the slope parameter of the diffraction cone for the reactions a+A® B+b . The resulting expressions are applied to p-p scattering. The results show that the model describes well the slope coefficient of the diffraction cone at energies below 102 GeV. For agreement with experiment at high energies, it is necessary to tune the parameters.

Spinning-off stringy electro-magnetic memories

We extend and generalise the string corrections to the EM memory to the Type I superstring including spin effects. Very much as in the simpler bosonic string context, the relevant corrections are non-perturbative in α′, slowly decaying (as 1/R) at large distances and modulated in retarded time u=t−R. For spin N states in the first Regge trajectory they entail a sequence of N derivatives wrt u on the ‘parent’ N=0 amplitude. We also briefly discuss how to include loop effects, that broaden and shift the string resonances, and how to modify our analysis for macroscopic semi-classical quasi-BPS coherent states, whose collisions may lead to detectable string memory signals in viable Type I models.

A First-Quantized Model for Unparticles and Gauge Theories around Conformal Window

We first quantize an action proposed by Casalbuoni and Gomis in 2014 that describes two massless relativistic scalar particles interacting via a conformally invariant potential. The spectrum is a continuum of massive states that may be interpreted as unparticles. We then obtain in a similar way the mass operator for a deformed action in which two terms are introduced that break the conformal symmetry: a mass term and an extra position-dependent coupling constant. A simple Ansatz for the latter leads to a mass operator with linear confinement in terms of an effective string tension σ. The quantized model is confining when σ≠0 and its mass spectrum shows Regge trajectories. We propose a tensionless limit in which highly excited confined states reduce to (gapped) unparticles. Moreover, the low-lying confined bound states become massless in the latter limit as a sign of conformal symmetry restoration and the ratio between their masses and σ stays constant. The originality of our approach is that it applies to both confining and conformal phases via an effective interacting model.

Rotational Resonances and Regge-like Trajectories in Lightly Doped Antiferromagnets.

Understanding the nature of charge carriers in doped Mott insulators holds the key to unravelling puzzling properties of strongly correlated electron systems, including cuprate superconductors. Several theoretical models suggested that dopants can be understood as bound states of partons, the analogues of quarks in high-energy physics. However, direct signatures of spinon-chargon bound states are lacking, both in experiment and theory. Here we propose a rotational variant of angle-resolved photo-emission spectroscopy (ARPES) and calculate rotational spectra numerically using the density-matrix renormalization group. We identify long-lived rotational resonances for an individual dopant, which we interpret as a direct indicator of the microscopic structure of spinon-chargon bound states. Similar to Regge trajectories reflecting the quark structure of mesons, we establish a linear dependence of the rotational energy on the superexchange coupling. The rotational peaks we find are strongly suppressed in standard ARPES spectra, but we suggest a multiphoton extension of ARPES which allows us to access rotational spectra. Our findings suggest that multiphoton spectroscopy experiments should provide new insights into emergent universal features of strongly correlated electron systems.