Related papers: Light-meson orbital excitations in the QCD string …
An approximate rotational symmetry of a heavy-light meson is viewed from a string picture. Using a simple string configuration, we derive a formula, $(M-m_c)^2=\pi\sigma L$, whose coefficient of the r.h.s. is just 1/2 of that of a light…
Stimulated by recent progress made by the LHCb Collaboration in discoveries of new bottom baryons, e.g., the $\Xi _{b}(6227)^{-}$ and the $\Sigma_{b}(6097)^{\pm}$, we re-examine the orbitally excited spectrum of the charmed and bottom…
Starting from the QCD Lagrangian we derive the effective action for massive quark and antiquark at large distances, corresponding to the minimal area low of the Wilson loop. The path integral method is used to quantize the system and the…
The light mesons tend to cluster near certain values of mass. As was noticed almost twenty years ago, the emergent degeneracy is of the same type as the dynamical $O(4)$-symmetry of the Coulomb potential in the hydrogen atom. The meson mass…
In previous works, a squared mass operator M^2 and a more common centre of frame Hamiltonian H_CM for the quark-antiquark system were obtained by using the only assumption that ln W (W being the Wilson loop correlator) can be written in QCD…
We calculate the light meson spectrum and the light quark masses by lattice QCD simulation, treating all light quarks dynamically and employing the Iwasaki gluon action and the nonperturbatively O(a)-improved Wilson quark action. The…
Two newly proposed Regge trajectory relations are employed to analyze the heavy-light systems. One of the relations is $M=m_1+m_2+C'+\beta_x\sqrt{x+c_{0x}}$, $(x=l,\,n_r)$. Another reads…
We provide first-principles non-perturbative determinations of the low-lying meson mass spectrum of large-$N$ QCD in the 't Hooft limit $N_{\scriptscriptstyle{\rm f}}/N\to 0$, as well as of three low-energy constants appearing in the QCD…
Modern spectroscopic data on light non-strange meson spectrum is analyzed. It is argued that the observed regularities of experimental spectrum for highly excited states favour a partial restoration of all approximate classical symmetries…
We use new high statistics data from CLAS and COMPASS on the nucleon's spin structure function at low Bjorken x and low virtuality, Q^2 < 0.5 GeV^2, together with earlier measurements from the SLAC E-143, HERMES and GDH experiments to…
We consider effective theory treatment for the lowest-lying $S$- and $P$-wave states of charmed mesons. In our analysis, quantum corrections and contributions from leading chiral and heavy quark symmetry breakings are taken into account.…
The large-$N_c$ masses of light vector, axial, scalar and pseudoscalar mesons are calculated from QCD spectral sum rules for a particular ansatz interpolating the radial Regge trajectories. The ansatz includes a linear part plus…
The light scalar meson spectrum is studied using the improved ladder QCD with the UA(1) breaking Kobayashi-Maskawa-'t Hooft interaction by solving the Schwinger-Dyson and Bethe-Salpeter equations. The dynamically generated…
We present estimates of light quarks masses using lattice data. Our main results are based on a global analysis of all the published data for Wilson and Staggered fermions, both in the quenched approximation and with $n_f=2$ dynamical…
We propose a novel approach to construction of hadron spectroscopy. The case of light nonstrange mesons is considered. By assumption, all such mesons above 1 GeV appear due to creation of constituent quark-antiquark pairs inside the pi or…
The spectrum of B and D mesons (including the low lying orbitally and radially excited states) is calculated using the quark-antiquark Hamiltonian derived from QCD in the einbein field formalism. Spin-spin and spin-orbit terms due to the…
Spin-dependent interaction in hadrons is considered in the approach of the QCD string. The string moment of inertia, which ensures the correct (inverse) Regge slope 2*pi*sigma, is found to suppress the spin-orbit interaction. For light…
The light scalar meson sigma(600) is known to appear at low excitation energy with very large width on top of continuum states. We investigate it in the QCD sum rule as an example of resonance structures appearing above the corresponding…
We revisit the model of mesons as rotating strings with massive endpoints and confront it with meson spectra. We look at Regge trajectories both in the (J,M2) and (n,M2) planes, where J and n are the angular momentum and radial excitation…
A new physical mechanism is suggested to explain the universal depletion of high meson excitations. It takes into account the appearance of holes inside the string world sheet due to $q\bar{q}$ pair creation when the length of the string…