Melting temperature of heavy quarkonium with a holographic potential up to sub-leading order

A calculation of the melting temperatures of heavy quarkonium states with the holographic potential was introduced in a previous work.In this paper,we consider the holographic potential at sub-leading order,which permits finite coupling corrections to be taken into account.It is found that this correction lowers the dissociation temperatures of heavy quarkonium.     

Quarkonium spectral functions with complex potential

We study quarkonium spectral functions at high temperatures using a potential model with complex potential. The real part of the potential is constrained by the lattice QCD data on static quark anti-quark correlation functions, while the imaginary part of the potential is taken from perturbative calculations. We find that the imaginary part of the potential has significant effect on quarkonium spectral functions, in particular, it leads to the dissolution of the 1S charmonium and excited bottomonium states at temperatures about 250 MeV and melting of the ground state bottomonium at temperatures slightly above 450 MeV.     

Collision dissociation of heavy quarkonia in dense partonic systems

The influence of collisions in a hot partonic medium on the formation of heavy quarkonia is investigated. We find that the initial color octet propagation of \(Q\bar Q\) pairs created in nuclear collisions leads to a large cross section for collision dissociation even before Debye screening of the quarkonium potential in the color singlet final state becomes effective. This leads to a sizeable suppression of quarkonium states in addition to previously considered effects. The concept of a quarkonium “formation time”, during which the \(Q\bar Q\) pair is not affected by the surrounding medium, is shown to be incorrect. In particular, we argue that the υ resonance will always be suppressed in nuclear collisions, contrary to recent suggestions that an unsuppressed υ state might signal quarkgluon plasma formation.     

Duality ine + e − annihilation

With the help of a relativistic generalization of the formula for the leptonic width of quarkonium in the semiclassical approximation it is shown that for any confinement potential nonsingular at the origin the sum of total cross sections for the production of the heavy quarkonium states \((Q\bar Q)_n\) with masses \(M_n \leqq \sqrt s\) ine ⁺ e ^?-annihilation is equal to the cross section at givens for the production of the free quark-antiquark pair \(Q\bar Q\) . We obtain also a family of dual sum rules for quarkonium which are in agreement with the available experimental data on charmonium and beautionium within experimental errors.     

Entropic destruction of heavy quarkonium in a rotating hot and dense medium from holography

Previous studies have indicated that the peak of the quarkonium entropy at the deconfinement transition can be related to the entropic force, which would induce the dissociation of heavy quarkonium. In this study, we investigated the entropic force in a rotating hot and dense medium using AdS/CFT correspondence. It was found that the inclusion of angular velocity increases the entropic force, thus enhancing quarkonium dissociation, while chemical potential has the same effect. The results imply that the quarkonium dissociates easier in rotating medium compared with the static case.     

Magnon condensation into a Q ball in 3He-B

The theoretical prediction of Q balls in relativistic quantum fields is realized here experimentally in superfluid 3He-B. The condensed-matter analogs of relativistic Q balls are responsible for an extremely long-lived signal of magnetic induction observed in NMR at the lowest temperatures. This Q ball is another representative of a state with phase coherent precession of nuclear spins in 3He-B, similar to the well-known homogeneously precessing domain, which we interpret as Bose-Einstein condensation of spin waves--magnons. At large charge Q, the effect of self-localization is observed. In the language of relativistic quantum fields it is caused by interaction between the charged and neutral fields, where the neutral field provides the potential for the charged one. In the process of self-localization the charged field modifies locally the neutral field so that the potential well is formed in which the charge Q is condensed.     

Quarkonium suppression

I discuss quarkonium suppression in equilibrated strongly interacting matter. After a brief review of basic features of quarkonium production I discuss the application of recent lattice data on the heavy quark potential to the problem of quarkonium dissociation as well as the problem of direct lattice determination of quarkonium properties in finite temperature lattice QCD.     

Derivation of a 1/r~2 potential term for Q in a potential model

We clarify the difference among potential models so far proposed to explain mass spectra of heavylight mesons via transformations of the vacuum.Applying our idea to QQ quarkonium,we obtain the extra term,1/r 2 with positive coefficient,other than non-relativistic potential terms expected for quarkonium.     

A possible unified quarkonium potential

We suggest a possible unified quarkonium potential, which combine the asymptotic freedom at the large-Q² and the multi-gluon effect at the lower-Q² regions with the confinement at large distance. The mass spectrum and the ratio of the leptonic decay of the (cc̄), (bb̄) and (tt̄) s-wave states are calculated. Our results which fit the experimental data very well show that they are sensitive to the scale parameter Λ in QCD.     

Linear or linear plus Coulomb potential for description of quarkonium spectra?

In previous works we explained theS andP-wave data on heavy quark spectroscopy for the spin-independent potential given by the combination of linear, harmonic or power-law and colour-Coulomb potentials. In the present work, we try to understand the same quarkonium spectra when the spin-independent part of the potential contains the linear potential only and the colour-Coulombic piece is treated perturbatively. We find that the present model cannot explain all the features ofS andP-wave data even at the cost of a large value of QCD scale parameter.     

A new phenomenological potential for heavy quarkonium

We suggest a new phenomenological potential for heavy quarkonium. The potential has a Lorentz vector term motivated by experimental leptonic widths for vector mesons and perturbative QCD at short distances and a Lorentz scalar term responsible for quark confinement at large distances. Using this potential we calculate the energy levels, leptonic decay widths, radiative transition rates and hadronic decay rates of the \(c\bar c, b\bar b\) and \(t\bar t\) systems. Most results agree well with the experiment.     

Final state gluon polarization in large transverse momentum quarkonium production

We calculate the polarization of the final state gluon in the processes thought to dominate large transverse momentum quarkonium production atep colliders ( \((\gamma g \to g^3 S_1 (Q\bar Q))\) ) and at hadron colliders \((gg \to g^3 S_1 (Q\bar Q), gg \to g^3 P_J (Q\bar Q) (J = 0,1,2))\) . We find that the polarization is never more than 10%.     

相对论效应对有限温下重夸克偶素的性质的影响

考虑相对论修正对重夸克偶素结合和分解所产生的作用，计算了重夸克偶素在热力学环境中的临界性质，并与非相对论模型理论进行了比较．     

Schrödinger vs. dirac bound state spectra of Q\bar Q-systems and a plausible lorentz structure of the effective power-law potential-systems and a plausible lorentz structure of the effective power-law potential

It is shown that a non-relativistic power-law potential model for the heavy quarks in the form V(r)=Ar ^v+V ₀, (A, ν>0) acquires relativistic consistency in generating Dirac bound states of \(Q\bar Q\) -system in agreement with the Schrödinger spectroscopy if the interaction is modelled by equally mixed scalar and vector parts as suggested by the phenomenology of fine-hyperfine splittings of heavy quarkonium systems in a non-relativistic perturbative approach.     

Survival of B c mesons in a hot plasma within a potential model

We extend a previous work on the study of heavy charmonia and bottomonia in a deconfined quark-gluon plasma by considering the B _c family of mesons. With the introduction of this bound state of a charm and a beauty quark, we investigate at finite temperature the behavior of the quarkonium, in an energy region between the ψ and the Y states.     

A study of a possible unified potential model

The various properties of quarkonium systems have been studies in the framework of a recently proposed potential model, which combines the asymptotic freedom at the largeQ ₂ and the multigluon effect at the lowerQ ₂ regions with the confinement at the large distance. Good agreements with experiments are found, including \(c\bar c\) and \(b\bar b\) energy levels, leptonic decay widths, and in particular the fine and hyperfine splittings. We also analyze the Lorentz structure of the confinement potential with reference to the charmonium and bottomium fine and hyperfine splittings. Our analyses conclude that almost pure scalar confinement is favored. The properties of \(t\bar t\) spectroscopies are studied over a wide range of \(M_{t\bar t}\) values (from 80 GeV to 200 GeV).     

Color screening melts quarkonium

We calculate quarkonium spectral functions in a quark-gluon plasma using a potential model based on full QCD lattice calculations of the free energy of a static quark-antiquark pair. We estimate the binding energy and the thermal width of different quarkonium states. The estimated upper limit for the dissociation temperatures is considerably lower than the ones suggested in the recent literature.     

Heavy quarkonia in a medium as a quantum dissipative system: master-equation approach

The problem of the evolution of a heavy quarkonium in a medium can be recast as that of a quantum dissipative system. Within the framework of the master-equation approach to open quantum systems, we consider the real-time dynamics of quarkonia. We find that in a plasma at fixed temperature, the populations of the various quarkonium states evolve together, while their momentum distribution satisfies a Fokker–Planck equation.     

Quarkonia with a variational method

A variational method, based in independent minimization of energy levels, is applied to quantum mechanical quarkonium systems. A discussion is presented of the method, with emphasis on quark mass dependence of energy levels (Feynman-Hellman theorem), on the behaviour of wave functions at the origin (Martin's theorem) and on the ordering of energy levels. The potential used in the applications is the Coulomb (4-vector) + Linear (4-scalar) potentials, the fine and hyperfine splittings being included by means of the Fermi-Breit hamiltonian. An attempt is made for an overall treatment of the known splittings (radials-wave, hyperfine and fine splittings) for all quarkonium systems, using an approximately flavour independent potential. Thep-wave splittings, as well as the hyperfine splittings, are shown to be particularly sensitive to the nature and mass dependence of the potential. In particular, asymptotic freedom can be more easily tested there. On the other hand, radial excitations provide the place where the set up of short range potential effects should be first detected. Some results concerning the ordinary mesons are presented, and it is specifically pointed out that strong restrictions exist for the masses of the ρ′ and theA ₁. Predictions for the toponium family are also presented.     

Comb of high‐Q Resonances in a Compact Photonic Cavity

The optical equivalent of the quantum mechanical oscillator is demonstrated in a photonic crystal cavity, owing to the balance of the background dispersion and a bichromatic potential. Consequently, several equi‐spaced resonances with large loaded Q factors are obtained within a very tiny volume. A detailed statistical analysis is carried out by exploiting the complex reflection spectra measured with Optical Coherent Tomography. The log‐normal distribution of the intrinsic Q‐factors is centered at 0.7 million. The device is made of Ga_0.5In_0.5P in order to suppress the two photon absorption in the Telecom spectral range considered here. This is crucial to turn the strong localization of light into ultra‐efficient parametric interactions.