Related papers: QCD String formation and the Casimir Energy
We study the emergence of quasicrystal configurations produced purely by quantum fluctuations in the ground-state phase diagram of interacting bosonic systems. By using a variational mean-field approach, we determine the relevant features…
We carry out three-dimensional numerical simulations to investigate the formation rate of semilocal strings. We find that the back-reaction of the gauge fields on the scalar field evolution is substantial, and leads to a significant…
Cosmological evolution of axionic strings is investigated by numerically solving field equations of a complex scalar field in 3+1 dimensions. It is shown that the global strings relax to the scaling solution with a significantly smaller…
The $2+1$-dimensional quantum dimer model on a square lattice, proposed by Rokhsar and Kivelson as a theory of layered superconductivity, is shown to be equivalent to a many-body theory of free, transversely oscillating strings obeying…
We show that a static central potential may provide a precise description of highly excited light unflavoured mesons. Due to string breaking this potential becomes of chromoelectric type at sufficiently large quark-antiquark distances…
The separation of a heavy quark and antiquark pair leads to the formation of a tube of flux, or string, which should break in the presence of light quark-antiquark pairs. This expected zero temperature phenomenon has proven elusive in…
I give an overview on experimental studies of the spectrum and the structure of the excited states of the nucleon and what we can learn about their internal structure. One focus is on the efforts to obtain a more complete picture of the…
We evaluate the cross section for electron-positron pair production by a single high energy photon in the space-time of a static, straight cosmic string. Energy and momentum conservation precludes this process in empty Minkowski space. It…
The two quantizations of QFT,as well as the attempt of unifying it with general relativity,lead us to consider that the internal structure of an elementary fermion must be twofold and composed of three embedded internal (bi)structures which…
We study the real-time dynamics of string breaking in quantum electrodynamics in one spatial dimension. A two-stage process with a clear separation of time and energy scales for the fermion--antifermion pair creation and subsequent charge…
Motivated by the gluon-chain model of flux tube formation, we compute and diagonalize the transfer matrix in lattice SU(2) gauge theory for states containing heavy static quark-antiquark sources, with separations up to one fermi. The…
We discuss new results in QCD obtained with string-based methods. These methods were originally derived from superstring theory and are significantly more efficient than conventional Feynman rules. This technology was a key ingredient in…
The mechanism of string creation for light quarks developed earlier is considered for nonzero quark chemical potential. A strong modification of the confining string due to finite quark density (chemical quark potential $\mu$) is observed.…
We report the results of a set of high precision simulations performed in the 3d gauge Ising model. We evaluated the interquark potential and the first few energy levels and compared them with the predictions obtained with the effective…
In string bit models, the superstring emerges as a very long chain of "bits", in which s fermionic degrees of freedom contribute positively to the ground state energy in a way to exactly cancel the destabilizing negative contributions of…
Spectrum of gluons in the adjoint source field is computed analytically using the QCD string Hamiltonian, containing only one parameter - string tension, fixed by meson and glueball spectrum. Spin splitting is shown to be small. A good…
We have earlier shown that cosmic strings moving through the plasma at the time of a first order quark-hadron transition in the early universe can generate large scale baryon inhomogeneities. In this paper, we calculate detailed structure…
We study the QCD color interactions between static two heavy quarks at zero temperature in a quenched SU(3) lattice gauge simulation: in addition to the standard singlet $q\bar{q}$ potentials, we calculate octet $q\bar{q}$ potentials,…
SO(10) cosmic strings formed during the phase transition Spin(10) $\rightarrow$ SU(5) $\times{\cal Z}_2$ are studied. Two types of strings --- one effectively Abelian and one non-Abelian --- are constructed and the string solutions are…
The Casimir energy for the transverse oscillations of a piecewise uniform closed string is calculated. In its simplest version the string consists of two parts I and II having in general different tension and mass density, but is always…