#### Filter Results:

- Full text PDF available (39)

#### Publication Year

1994

2014

- This year (0)
- Last 5 years (2)
- Last 10 years (9)

#### Publication Type

#### Co-author

#### Journals and Conferences

Learn More

A Wilsonian renormalisation group is used to study nonrelativistic twobody scattering by a short-ranged potential. We identify two fixed points: a trivial one and one describing systems with a bound state at zero energy. The eigenvalues of the linearised renormalisation group are used to assign a systematic power-counting to terms in the potential near eachâ€¦ (More)

- Michael C. Birse
- 1996

The commonly used types of effective theory for vector mesons are reviewed and their relationships clarified. They are shown to correspond to different choices of field for spin-1 particles and the rules for transforming between them are described. The importance of respecting chiral symmetry is stressed. The choice of fields that transform homogeneouslyâ€¦ (More)

- Michael C. Birse
- 1994

Partial restoration in nuclear matter of the chiral symmetry of QCD is discussed together with some of its possible signals. Estimates of corrections to the leading, linear dependence of the quark condensate are found to be small, implying a significant reduction of that condensate in matter. The importance of the pion cloud for the scalar quark density ofâ€¦ (More)

We apply the renormalisation-group to two-body scattering by a combination of known long-range and unknown short-range forces. A crucial feature is that the low-energy effective theory is regulated by applying a cut-off in the basis of distorted waves for the long range potential. We illustrate the method by applying it to scattering in the presence of aâ€¦ (More)

Group-theoretic arguments are used to determine the dependence of twopoint correlators of quark bilinears on the current quark masses. The leading difference between Ï€ and Î´ correlators is found to be of orderms times a U(1)Aviolating correlator. These general arguments are consistent with Schaeferâ€™s observation that if U(1)A violation persists to highâ€¦ (More)

We study the instabilities of quark matter in the framework of a generalized Nambuâ€“Jona-Lasinio model, in order to explore possible competition between three-quark clustering to form nucleons and diquark formation leading to color superconductivity. Nucleon and âˆ† solutions are obtained for the relativistic Faddeev equation at finite density and theirâ€¦ (More)

We consider a nonlocal version of the NJL model, based on a separable quark-quark interaction. The interaction is extended to include terms that bind vector and axial-vector mesons. The nonlocality means that no further regulator is required. Moreover the model is able to confine the quarks by generating a quark propagator without poles at real energies.â€¦ (More)

We present a calculation of the fourth-order (NLO) contribution to spin-dependent Compton scattering in heavy-baryon chiral perturbation theory, and we give results for the four spin polarisabilities. No low-energy constants, except for the anomalous magnetic moments of the nucleon, enter at this order. The NLO contributions are as large or larger than theâ€¦ (More)

- Abdellatif Abada, Michael C. Birse
- 1997

We investigate the time evolution of a system of quarks interacting with Ïƒ and pion fields starting from an initial configuration consisting of a tube of hot quark plasma undergoing a boost-invariant longitudinal expansion. We work within the framework of the linear sigma model using classical transport equations for the quarks coupled to the mean-fieldâ€¦ (More)

- Boris Krippa, Niels R. Walet, Michael C. Birse
- 2013

We study the ratio between the fermion-fermion scattering length and the dimer-dimer scattering length for systems of nonrelativistic fermions, using the same functional renormalisation technique as previously applied to fermionic matter. We find a strong dependence on the cutoff function used in the renormalisation flow for a two-body truncation of theâ€¦ (More)