Related papers: Pi-Pi scattering lengths at finite temperature
Using first-principles calculation within Quantum Chromodynamics, we are able to determine a pattern of strangeness=1 resonances which appear as complex singularities within coupled $\pi K$, $\eta K$ scattering amplitudes. We make use of…
Magnetization noise measurements on the spin ice Dy${}_2$Ti${}_2$O${}_7$ have revealed a remarkable `pink noise' power spectrum $S(f,T)$ below 4 K, including evidence of magnetic monopole excitations diffusing in a fractal landscape.…
We investigate complex-temperature singularities in the Ising model on the triangular lattice. Extending an earlier analysis of the low-temperature series expansions for the (zero-field) susceptibility $\bar\chi$ by Guttmann \cite{g75} to…
We compute the scattering amplitude for pion scattering in Wilson chiral perturbation theory for two degenerate quark flavors. We consider two different regimes where the quark mass m is of order (i) a\Lambda_QCD^2 and (ii)…
We have performed polarized Raman scattering measurements on the newly discovered superconductor Ta$_{4}$Pd$_{3}$Te$_{16}$ ($T_c = 4.6$ K). We observe twenty-eight out of thirty-three Raman active modes, with frequencies in good accordance…
Recent microwave conductivity measurements of detwinned, high-purity, slightly overdoped YBa$_{2}$Cu$_{3}$O$_{6.993}$ crystals reveal a linear temperature dependence and a near-Drude lineshape for temperatures between 1 and 20 K and…
We present a density functional perturbation theory approach to estimate the transition temperature of the charge density wave transition of TiSe2. The softening of the phonon mode at the L-point where in TiSe2 a giant Kohn anomaly occurs,…
We calculate the complete one-loop effective potential for SU(2) gauge bosons at temperature T as a function of two variables: phi, the angle associated with a non-trivial Polyakov loop, and H, a constant background chromomagnetic field.…
Peculiarities of obtaining parameters for broad multi-channel resonances from data are discussed analyzing the experimental data on processes $\pi\pi\to\pi\pi,K\bar{K}$ in the $I^GJ^{PC}=0^+0^{++}$ channel in a model-independent approach…
By using a thermal Finite Energy QCD Sum Rule, we are able to establish the temperature dependence of the $g_{\omega \rho \pi}(T)$ strong coupling. It turns out that this coupling decreases as a function of temperature, vanishing at the…
We propose a method to calculate scattering amplitudes using the Bethe-Salpeter wave function inside the interaction range on the lattice. For an exploratory study of this method, we evaluate a scattering length of $I=2$ S-wave two pions by…
The pion-deuteron scattering length is computed to next-to-next-to-leading order in baryon chiral perturbation theory. A modified power-counting is then formulated which properly accounts for infrared enhancements engendered by the large…
We use the density matrix renormalization group method (DMRG) to compute the frequency and momentum resolved spin-spin correlation functions of a dimerized spin-1/2 chain under a magnetic field at finite temperature. The spectral features…
Taking advantage of the known analytic expression of the eigenfunctions and eigenenergies of the Morse Hamiltonian, explicit expressions are found for the scattering length $a$ and the effective range $r_e$ which determine the s-wave…
pi pi scattering at low energy is sensitive to the structure of the QCD vacuum. I review the calculations of the pi pi scattering lengths and phases, and group them in three cathegories: 1. those based on very general theoretical…
The thermal and density corrections, in terms of the isospin chemical potential $\mui $, to the mass of the pions, the decay constant and different condensates are studied in the framework of the SU(2) low energy effective chiral lagrangian…
General interest in a precise determination of the threshold pi-pi amplitudes has recently increased markedly due to a controversy regarding the size of <0|qbar q|0>, the scalar quark condensate. This paper examines the current experimental…
It is shown that the notion of the finite pairing interaction energy range $T_d$ results in a linear temperature dependence of the London magnetic penetration depth $\Delta \lambda / \lambda (0) = (T/T_d)(2/\pi)\ln 2$ at low temperature, in…
A theory of non-equilibrium (``shot'') noise and high frequency conductance in diffusive mesoscopic conductors with screening is presented. Detailed results are obtained for two simple geometries, for both large and short electron-electron…
We report measurements of the temperature $T $ dependence of the linear polarization $\langle P\rangle $ of the thermal radiation emitted by thin, incandescent tungsten wires. We investigated an interval ranging from a little above room…