Showing papers by "Manfried Faber published in 2006"

On the renormalization of the two-point Green function in the sine-Gordon model

Abstract: We analyse the renormalizability of the sine-Gordon model using the two-point causal Green function. We show that all divergences can be removed by the renormalization of the dimensional coupling constant using the renormalization constant Z1, calculated in Faber and Ivanov (2003 J. Phys. A: Math. Gen. 36 7839) within the path-integral approach. We calculate the Gell-Mann–Low function and solve the Callan–Symanzik equation for the two-point Green function. We analyse the renormalizability of Gaussian fluctuations around a soliton. We show that Gaussian fluctuations around a soliton solution are renormalized like quantum fluctuations around the trivial vacuum and do not introduce any singularity to the sine-Gordon model at β2 = 8π. We calculate the correction to the soliton mass, caused by Gaussian fluctuations around a soliton, within the discretization procedure for various boundary conditions and find complete agreement with our result, obtained in continuous space–time.

Estimate of the σ K N ( I = 1 ) ( 0 ) -term value from the energy-level shift of kaonic hydrogen in the ground state

Abstract: Using the experimental data on the energy-level shift of kaonic hydrogen in the ground state [Beer et al., Phys. Rev. Lett. 94, 212302 (2005)] and the theoretical value of the energy-level shift, calculated within the phenomenological quantum field theoretic approach to the description of strong low-energy $\overline{K}N$ and $\overline{K}NN$, interactions, we estimate the value of the ${\ensuremath{\sigma}}_{KN}^{(I=1)}(0)$ term of low-energy $\overline{K}N$ scattering. We get ${\ensuremath{\sigma}}_{KN}^{(I=1)}(0)=433\ifmmode\pm\else\textpm\fi{}132\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$. This shows the absence of strange quarks in the proton structure.