ORDER PARAMETER AND EFFECTIVE POTENTIAL

The first quantum correction for the order parameter in the case of SU (2) gauge theory at a finite temperature in the presence of a background field (A(O)a)B = const. is calculated. We note that it is necessary to express the value of the background field in terms of some physical measured value to get a gauge independent expression for any other calculated physical parameters of the theory. In this paper the value of the background field in terms of the order parameter which is parameterized in the following way: < L > A(O)B = cos(gA(O)cl/2T). It is shown that the two-loop effective potential for the field (gA(O)cl) is gauge independent. This effective potential has a minimum when < L > = +/- 1.