Related papers: Stability of strings binding heavy-quark mesons
We use a constituent model to analyze the stability of pentaquark $\bar Q qqqq$ configurations with a heavy antiquark $\bar c$ or $\bar b$, and four light quarks $uuds$, $ddsu$ or $ssud$. The interplay between chromoelectric and…
Superconducting cosmic strings can exhibit longitudinal, pinching instabilities in some regions of the parameter space. We make predictions about the onset of this instability using the thin string approximation (TSA) and develop an…
We consider the leading finite-size effects on some structure constants for the $\eta$ - deformed $AdS_5\times S^5$ background in the framework of the semiclassical approach. The leading finite-size corrections are derived for the cases…
We revisit the classical instability of closed strings in the Abelian Higgs model. The instability is expressed by a vanishing energy as the torus-like configuration shrinks to zero size. We treat the radius of the torus as a collective…
The heavy quarks $c$ and $b$ stabilize exotic meson $(qq\bar q \bar q)$ and baryon $(qqqq \bar q)$ states. We discuss work with M. Karliner on molecules containing $c \bar c$ and $b \bar b$; the first doubly charmed baryon; isospin…
The investigation of the q deformation of the S-matrix for excitations on the string world sheet in AdS5 x S5 is continued. We argue that due to the lack of Lorentz invariance the situation is more subtle than in a relativistic theory in…
The characterization and mechanical stability of charged thin shells with spherical symmetry are analyzed in the context of Einstein-Born-Infeld theory. The study of stability is performed by considering linearized perturbations preserving…
The significant heavy threshold effect is found in the supersymmetric SU(5) model with two adjoint scalars, one of which is interpreted as a massive string mode decoupled from the lower-energy particle spectra. This threshold related with…
In some models, exotic baryons with strangeness and anticharm or antibeauty should exist and even be stable against strong decay. We consider the stability of such possible exotic baryons, which in the constituent quark picture are called…
We review the chromoelectric and chromomagnetic mechanisms that tentatively lead to stable or metastable multiquark configurations. An alternative interpretation of the dynamics is the quark interchange between hadrons, as illustrated in…
We study the out-of-equilibrium evolution of a strongly interacting quantum spin chain which is mapped on a system of hard rods that are coherently deposited on and removed from a lattice. We show that this closed quantum system approaches…
We compute some normalized structure constants in the $\eta$-deformed $AdS_5\times S^5$ in the framework of the semiclassical approach. This is done for the cases when the "heavy" string states are finite-size giant magnons carrying one…
The stability and equation of state of quark matter are studied within both two-flavor and (2+1)-flavor Nambu-Jona-Lasinio (NJL) models including the vector interactions. With a free parameter $\alpha$, the Lagrangian is constructed by two…
The confinement of quarks in hadrons occurs due to formation of QCD string. At large separation between the quarks the QCD string breaks into pieces due to light quark-antiquark pair creation. We argue that there exist a critical background…
The configuration of typical highly excited (M >> M_s ~ (alpha')^{-1/2}) string states is considered as the string coupling g is adiabatically increased. The size distribution of very massive single string states is studied and the mass…
The equivalence of quantum field theory and string theory as exemplified by the AdS/CFT correspondence is explored from the point of view of lightcone quantization. On the string side we discuss the lightcone version of the static string…
We consider the leading large string tension correction to correlation functions of three vertex operators of particular massive string states in AdS_5 x S^5 string theory. We assume that two of these states are "heavy" carrying large spins…
We show that the natural resonant frequency of a suspended flexible string is significantly modified (by one order of magnitude) by adding a freely pivoting attached mass at its lower end. This articulated system then exhibits complex…
We construct solutions of non-uniform black strings in dimensions from $D \approx 9$ all the way up to $D = \infty$, and investigate their thermodynamics and dynamical stability. Our approach employs the large-$D$ perturbative expansion…
The evolution of small perturbations around rotating black branes and strings, which are low energy solutions of string theory, are investigated. For simplicity, we concentrate on the Kerr solution times transverse flat extra dimensions,…