The spin-dependent operators for heavy quarkonium hybrids have been recently obtained in a nonrelativistic effective field theory approach up to next-to-leading order in the heavy-quark mass expansion. In the effective field theory for hybrids several operators not found in standard quarkonia appear, including an operator suppressed by only one power of the heavy-quark mass. We compute the matching coefficients for these operators in the short heavy-quark-antiquark distance regime, $r\ll 1/Λ_{\rm QCD}$, by matching weakly-coupled potential NRQCD to the effective field theory for hybrids. In this regime the perturbative and nonperturbative contributions to the matching coefficients factorize, and the latter can be expressed in terms of purely gluonic correlators whose form we explicitly calculate with the aid of the transformation properties of the gluon fields under discrete symmetries. We detail our previous comparison with direct lattice computations of the charmonium hybrid spectrum, from which the unknown nonperturbative contributions can be obtained, and extend it to data sets with different light-quark masses.
We give an example of modeling phenomenological heavy-quark potentials in a five-dimensional framework nowadays known as AdS/QCD. In particular we emphasize the absence of infrared renormalons.
The magnetic dipole moments of the spin-$\frac{1}{2}$ doubly heavy baryons are extracted in the framework of light-cone QCD sum rule. The electromagnetic properties of the doubly heavy baryons encodes important information of their internal structure. The results for the magnetic dipole moments of doubly heavy baryons acquired in this work are compared with the predictions of the other theoretical approaches.
Slight sophistications of the QCD sum-rule formalism may have great impact on the reliability of predicted hadron observables, as exemplified for the case of heavy-meson decay constants.
We employ a new method, "gauge cooling", to stabilize complex Langevin simulations of QCD with heavy quarks. The results are checked against results obtained with reweigthing; we find agreement within the estimated errors. The method allows us to go to previously unaccessible high densities.
Recent results relevant for the B-physics phenomenology, obtained from lattice QCD simulations by the APE Collaboration, are reviewed. This includes the B0-B0bar mixing amplitude, B-> pi semileptonic decay and the relative width difference of B0_s mesons, $(ΔΓ/Γ)_{B_s}$.
We investigate the nature of the deconfinement and Roberge-Weiss transition in the heavy quark regime for finite real and imaginary chemical potential within the functional approach to continuum QCD. We extract the critical phase boundary between the first order and cross-over regions, and also explore tricritical scaling. Our results confirm previous ones from finite volume lattice studies.
In this report, the most recent and precise estimates of masses of ground state baryons using lattice QCD are discussed. Considering the prospects in the heavy baryon sector, lattice estimates for these are emphasized. The first and only existing lattice determination of the highly excited $Ω_c$ excitations in relation to the recent LHCb discovery is also discussed.
For some experimental guidelines of the next millenium, I review the determinations of the masses, decays and mixings of the gluonia, scalar and hybrid mesons from QCD spectral sum rules and low-energy theorems, and compare them with the lattice.
Assuming QCD exhibits an interacting fixed-point behaviour in the ultraviolet regime, I argue that the axion can be substantially heavier than in the conventional case of asymptotically free QCD due to the enhanced contribution of small size instantons to its mass.
A review of QCD-based theory approaches to study the heavy-flavor and exotic hadrons is given. The focus is on the results from lattice QCD and from lattice QCD complemented by effective field theories. Both approaches are first briefly introduced and applied in few examples. Then the status of various hadrons sectors is presented.
Some interesting heavy-flavor questions are mentioned that may yield to the methods of lattice QCD. Special emphasis is placed on topics which arise in the discussion of CP violation in $B$ decays. Other subjects include quarkonium and light-quark systems and some potential applications outside QCD.
We consider how two classes of heavy particles: extra vector-like families, and strongly interacting superpartners, manifest themselves below threshold, by interference of virtual loops with normal QCD processes. Quantitative estimates are presented.
This paper is a review of heavy quarks in lattice gauge theory, focusing on methodology. It includes a status report on some of the calculations that are relevant to heavy-quark spectroscopy and to flavor physics.
Flux tube model predictions for hybrid meson decays are beginning to be confronted by Lattice QCD. We compare the two approaches for the $S$-wave decay of the exotic $1^{-+}$, and find excellent agreement. Results suggest that in Strong QCD, \qq~ creation occurs with S=1.
I review the current status of lattice calculations of heavy quark quantities. Particular emphasis is placed on leptonic and semileptonic decay matrix elements.
In the last few years, lattice QCD has made a dramatic progress in understanding the physics of hadrons containing heavy quarks, from the first principle. This review summarises the major achievements.
The ground state and excited spectra of baryons containing three identical heavy quarks, $b$ or $c$, have been recently calculated in nonperturbative lattice QCD. The energy of positive and negative parity excitations has been determined with high precision. Lattice results constitute a unique opportunity to learn about the quark-confinement mechanism as well as elucidating our knowledge about the nature of the strong force. We analyze the nonperturbative lattice QCD results by means of heavy-quark static potentials derived using SU(3) lattice QCD. We make use of different numerical techniques…
We study the effect of $Bπ$ continuum in the QCD sum rule analysis of the heavy meson doublet $(0^+, 1^+)$ in the leading order of heavy quark effective theory. New sum rules are derived for the leading order binding energy ${\bar Λ_{+,{1\over 2}}}$ and pionic coupling constant $g'$.
Updated predictions for the decay constants of the D, Ds, B and Bs mesons obtained from Borel QCD sum rules for heavy-light currents are presented and compared with the recent lattice averages performed by the Flavor Lattice Averaging Group. An excellent agreement is obtained in the charm sector, while some tension is observed in the bottom sector. Moreover, available lattice and QCD sum-rule calculations of the decay constants of the vector D*, Ds*, B* and Bs* mesons are compared. Again some tension in the bottom sector is observed.
We review the recent theoretical progress in heavy quarkonium spectroscopy within the boundstate theory based on perturbative QCD. New microscopic pictures of the heavy quarkonium systems are obtained.
Compared with lattice QCD, isospin breaking of heavy-meson decay constants from QCD sum rules agrees for $D$ mesons but disagrees (by a factor of four) for $B$ mesons.
Finite temperature QCD sum rules are applied to the behaviour of charmonium and bottonium states, leading to their survival at and beyond the critical temperature for deconfinement. Di-muon production in heavy-ion collisions in the $ρ$-region is also discussed.
In this talk, we give a short review of our recent works on studying the singly heavy baryon, doubly heavy baryon, and triply heavy baryon spectra from QCD sum rules.
We discuss recent progress in the study of in-medium heavy quarkonium using first-principles lattice QCD calculations and effective field theory. In particular our focus lies on real-time information carried by QCD spectral functions and we report on a novel strategy for their extraction from Euclidean-time simulations. Combining an effective description for heavy quarks with finite temperature lattice QCD we compute in-medium spectra providing insight in heavy quarkonium melting in a static thermal medium. On the other hand we use spectral information to extract the complex in-medium potentia…
QCD sum rules for decay constants of heavy mesons with $u$ or $d$ quark yield for $B$ mesons much less isospin breaking than lattice QCD but good agreement for $D$ mesons.
We investigate the effects produced by the three-momentum scale $\sqrt{mΛ_{QCD}}$ in the strong coupling regime of heavy quarkonium. We compute the leading non-vanishing contributions due to this scale to the masses and inclusive decay widths. We find that they may provide leading corrections to the S-wave decay widths but only subleading corrections to the masses.
I review recent progress in lattice QCD at non-zero temperature whith emphasis on the calculations of equation of state and the properties of heavy quar anti-quark pairs at high temperatures. I also briefly discuss the deconfinement and chiral symmetry restoring aspects of the QCD transition at finite temperature
We give an introduction to the special problems encountered in a treatment of HQET beyond perturbation theory in the gauge coupling constant. In particular, we report on a recent test of HQET as an effective theory for QCD and discuss how HQET can be implemented on the lattice including the non-perturbative matching of the effective theory to QCD.
We study topological defects constructed from diagonal and non-diagonal gluons in Abelian projection of zero temperature lattice QCD. We compare results obtained in the quenched and non-quenched vacuum field configurations and show that the density of hybrids is higher than the density of monopoles. The density of some hybrids is sensitive to the presence of the virtual fermions.
The mass spectroscopy of exotic meson states is scrutinized in the AdS/QCD paradigm. The differential configurational entropy is then used to study, derive, and analyze the mass spectrum of excited exotic vector meson resonances, whose configurational stability is also addressed. For it the hadronic molecule, the hadrocharmonium, and the hybrid description of heavy-quark exotic mesonic states are employed to more precisely match experimental data in the Particle Data Group and also to predict the next generations of heavy-quark QCD exotica in the $Z_c$, $Y$, $π_1$, and $Z_b$ exotic meson famil…
We compute masses of bottomonium and charmonium bound states using a Schrödinger equation with a heavy quark-antiquark potential including $1/m$ and $1/m^2$ corrections previously derived in potential Non-Relativistic QCD and computed with lattice QCD. This is a preparatory step for a future project, where we plan to take into account similar corrections to study quarkonium resonances and tetraquarks above the lowest meson-meson thresholds.
Masses of the p-wave excited heavy baryons have been calculated to the Lambda_{QCD}/m_Q order using QCD sum rule method within the framework of heavy quark effective theory. Numerical results for kinetic energy lambda_1 and chromo-magnetic interaction lambda_2 are presented. The splitting between spin 1/2 and 3/2 doublet derived from our calculation is given, for which the agreement with the current experiment is desirable.
In this article, we study the ${3\over 2}^+$ heavy and doubly heavy baryon states $Ξ^*_{cc}$, $Ω^*_{cc}$, $Ξ^*_{bb}$, $Ω^*_{bb}$, $Σ_c^*$, $Ξ_c^*$, $Ω_c^*$, $Σ_b^*$, $Ξ_b^*$ and $Ω_b^*$ by subtracting the contributions from the corresponding ${3\over 2}^-$ heavy and doubly heavy baryon states with the QCD sum rules, and make reasonable predictions for their masses.
We argue that consistency of the combined heavy quark and chiral effective lagrangian requires the QCD scale which multiplies $1/M$ in the heavy quark expansion to be the chiral symmetry breaking scale, $Λ_{CSB}$, rather than the QCD scale, $Λ_{QCD}$. This means that either there is large uncertainty in the accuracy with which the heavy quark effective theory can be applied to $c$ quarks or the cutoff scale of the heavy quark chiral effective theory is lower than has been assumed.
The radiative decays of heavy baryons and lowest three doublets of heavy mesons are studied with the light cone QCD sum rules in the leading order of heavy quark effective theory.
Using the analytic properties of two-point functions in QCD, as well as unitarity, bounds on the B meson form factor F(q^2) can be derived. Heavy quark spin symmetry, correctly taken into account, is shown to improve these bounds significantly.
We study the phase structure of lattice QCD with heavy quarks at finite temperature and density by a histogram method. We determine the location of the critical point at which the first-order deconfining transition in the heavy-quark limit turns into a crossover at intermediate quark masses through a change of the shape of the histogram under variation of coupling parameters. We estimate the effect of the complex phase factor which causes the sign problem at finite density, and show that, in heavy-quark QCD, the effect is small around the critical point. We determine the critical surface in 2+…
Using a specific scheme of the QCD sum rules for heavy quarkonium in the leading approximation over the inverse heavy quark mass, one gets the estimate of the difference between the masses of the heavy meson and heavy quark $\bar Λ= 0.59\pm 0.02$ GeV.
This review of the Quantum Chromodynamics (QCD),the early universe Cosmoloical Phase Transition from the Quark-Gluon Plasma (QGP) to our present universe (QCDPT), Relativistic Heavy Ion Collisions (RHIC) which can produce the QGP, the possible detection of the QGP produced by the production of mixed hybrid heavy quark mesons. We also review recent studies of the production of mixed heavy quark hybrids via RHIC and heavy quark meson supression in p-Pb and Pb-Pb collisions.
We present an analytical calculation of the $α_s$ corrections for the coefficient of $ρ_D/m_Q^3$ term in the heavy quark expansion for the inclusive semileptonic decays of heavy hadrons, such as $B \to X_c \ell \barν$. The full dependence of the coefficient on the final-state quark mass is taken into account. Our result leads to further improvement of the theoretical predictions for the precision determination of CKM matrix element $|V_{cb}|$.
We discuss a minimal holographic model for the description of heavy-light and light mesons with chiral symmetry, defined in a slab of AdS space. The model consists of a pair of chiral Yang-Mills and tachyon fields with specific boundary conditions that break spontaneously chiral symmetry in the infrared. The heavy-light spectrum and decay constants are evaluated explicitly. In the heavy mass limit the model exhibits both heavy-quark and chiral symmetry and allows for the explicit derivation of the one-pion axial couplings to the heavy-light mesons.
We review the developments of QCD multipole expansion and its applications to hadronic transitions and some radiative decays of heavy quarkonia. Theoretical predictions are compsred with updated experimental results.
We construct the heavy baryonic currents by using the Bethe-Salpeter wave functions in the heavy quark limit. We discuss the one-loop renormalization of these heavy baryonic currents as well as their two-point correlators up to the order $1/M_h$. For a special case, we do the QCD sum rule for masses of the doublet (3/2,5/2).
We review recent calculations of second order corrections to heavy quark decays. Techniques developed in this context are applicable to many processes involving heavy charged particles, for example the nonabelian dipole radiation. Calculations involving relativistic radiating particles are also discussed.
We give an overview over recent calculations of baryonic correlator functions with finite mass quarks in view on their applicability for QCD sum rules. The QCD sum rule method is then demonstrated within the Heavy Quark Effective Theory.
Non-relativistic bound state theories for QED and QCD have become fairly mature and amenable to a textbook-level understanding and computation. In this talk we give an introductory review of the following subjects related to the recent computation of the heavy quarkonium spectrum using perturbative QCD: (1) Technological developments in higher-order computation, (2) Physics predictions, (3) Challenge towards analytic evaluation of the 3-loop static QCD potential.
We present the two-loop virtual QCD corrections to the production of heavy quarks in gluon fusion. The results are exact in the limit when all kinematical invariants are large compared to the mass of the heavy quark up to terms suppressed by powers of the heavy-quark mass. Our derivation uses a simple relation between massless and massive QCD scattering amplitudes as well as a direct calculation of the massive amplitude at two loops. The results presented here together with those obtained previously for quark-quark scattering form important parts of the next-to-next-to-leading order QCD correc…
We review recent developments in QCD pertaining to its application to weak decays of heavy hadrons. We concentrate on exclusive rare and nonleptonic B-meson decays, discussing both the theoretical framework and phenomenological issues of current interest.
In this article, we restudy the mass spectrum of the ground state triply-heavy baryon states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 6 in a consistent way and preforming a novel analysis. It is the first time to take into account the three-gluon condensates in the QCD sum rules for the triply-heavy baryon states.
