arXiv subjects

Petrus Pennanen

Publications and source records attributed to Petrus Pennanen.

3 recordsLinked to original sources

arXiv1997

Comparing improved actions for SU(2)

In order to help the user in choosing the right action a performance comparison is done for seven improved actions. Six of them are Symanzik improved, one at tree-level and two at one-loop, all with or without tadpole improvement. The seventh is an approximate fixed point action. Observables are static on- and off-axis two-body potentials and four-body binding energies, whose precision is compared when the same amount of computer time is used by the programs.

hep-lat↗

arXiv1997

Continuum extrapolation of energies of a four-quark system in lattice gauge theory

A continuum extrapolation of static two- and four-quark energies calculated in quenched SU(2) lattice Monte Carlo is carried out based on Sommer's method of setting the scale. The beta-function is obtained as a side product of the extrapolations. Four-quark binding energies are found to be essentially constant at beta >= 2.35 unlike the two-body potentials. A model for four-quark energies, with explicit gluonic degrees of freedom removed, is fitted to these energies and the behaviour of the parameters of the model is investigated. An extension of the model using the first excited states of the two-body gluon field as additional basis states is found to be necessary for quarks at the corners of regular tetrahedra.

hep-lat↗

arXiv1996

Four Quarks from Lattice to the Continuum

A continuum extrapolation of static four- and two-quark energies calculated in quenched SU(2) is done based on Sommer's method of setting the scale. A model for four-quark energies with explicit gluonic degrees of freedom removed is fitted to these energies and the behavior of the parameters of the model is investigated.

hep-lat↗