2 The e.o.m. which we obtain for the em field is Maxwell-like, with the current given by the charged W ± fields, which is physically reasonable. In general, the e.o.m. are complicated coupled partial differential equations, in which solutions for the Higgs and Stop fields must be found to obtain the current for the em field equation. In the present paper, however, we introduce an I-spin formulation which allows us to uncouple the e.o.m. for the W ± fields, and carry out a study of spherically symmet- ric EW bubble nucleation. For pure nucleation of a bubble we first solve the W ± e.o.m. numerically without leptons, and obtain solutions for the em field using a fit to these numerical solutions for the W ± fields. Next we include the electron current and solve the new equations for the electromagnetic field. The solutions have an instanton-like form near the bubble wall, as expected. These are the first solu- tions for the electromagnetic field from EWPT nu- cleation that have been obtained from the EW La- grangian. Due to spherical symmetry during nu- cleation only electric fields are produced. These give the initial fields for bubble collisions. For the derivation of EW cosmological magnetic seeds, the more complicated collision problem must also be solved[21] In Section II we present the EW-MSSM model, in- cluding fermions, and derive the e.o.m. for the gauge fields and the Higgs and Stop fields. In Section III the I-Spin ansatz is used to separate the gauge fields, and we present the solutions for the em field with- out fermions. In Section IV we include electrons, the mmost important fermion for em field creation, and find the em field. Our conclusions are given in Section V In this section we derive the equations of mo- tion for the standard Weinberg-Salam EW model extended to a MSSM model with the addition of a Stop field, the partner to the top quark. all other partners of the standard model fields are integrated out. with j representing all fermions, while the sum over c is just for charged fermions. The first term in L fermion gives the interaction of fermions with the gauge fields, while second term corresponds to the Higgs EWPT creation of fermion masses. We neglect these masses, as well as fermion masses created by the Stop, in the present work. The effective Higgs and Stop potentials are taken as where the W $^{i}$, with i = (1,2), are the W $^{+}$, W − fields, C a µ is an SU(3) gauge field, (Φ, Φ$_{s}$) are the (Higgs, right-handed Stop fields), ( τ $^{i}$, λ$^{a}$) are the (SU(2),SU(3) generators, and the electromagnetic and Z fields are defined as where the pure C a µ term is omitted in L 1 and The standard fermion Lagrangian, L fermion has the form B. MSSM EW Equations of Motion Without Fermions A. MSSM EW Lagrangian with Fermions II. MSSM EW EQUATIONS OF MOTION WITH RIGHT-HANDED STOP L MSSM = L 1 + L 2 + L 3 + L fermion (1) V (Φ) = − µ $^{2}$| Φ | 2 + λ | Φ | 4 V$_{hs}$ (Φ , Φ$_{s}$) = − µ 2 $_{s}$| Φ$_{s}$ | 2 + λ$_{s}$ | Φ$_{s}$ | 4 (5) + λ$_{hs}$ | Φ | $^{2}$| Φ$_{s}$ | $^{2}$. L fermion = ∑ j [ ¯ ψ j $_{L}$γ$^{µ}$( i∂$_{µ}$ − g 2 τ · W$_{µ}$ − g $_{′}$Y 2 B$_{µ}$ ) ψ j L + ¯ ψ j $_{R}$γ$^{µ}$( i∂$_{µ}$ − g $_{′}$Y 2 B$_{µ}$ ) ψ j $_{R}$] + ∑ c f i ¯ ψ c $_{L}$Φ ψ c R , (4) A em µ = 1 √ g 2 + g ′ $_{2}$( g $^{′}$W 3 µ + gB$_{µ}$ ) Z$_{µ}$ = 1 √ g 2 + g ′ $_{2}$( gW 3 µ − g $^{′}$B$_{µ}$ ) . (3) W i µν = ∂$_{µ}$W i ν − ∂$_{ν}$W i µ − gϵ$_{ijk}$W j $_{µ}$W k ν (2) B$_{µν}$ = ∂$_{µ}$B$_{ν}$ − ∂$_{ν}$B$_{µ}$ , L 1 = − 1 4 W i $_{µν}$W iµν − 1 4 B$_{µν}$B µν L 2 = | ( i∂$_{µ}$ − g 2 τ · W$_{µ}$ − g ′ 2 B$_{µ}$ )Φ | 2 − V (Φ) L 3 = | ( i∂$_{µ}$ − g$_{s}$ 2 λ $^{a}$Ca $_{µ}$)Φ$_{s}$ | 2 − V$_{hs}$ (Φ$_{s}$ , Φ) L fermion = standard Lagrangian for fermions ,