Fermionic kinetic mixing

[Amin]

Hi Florian,

When adding an extra vector superfield C to the MSSM and allowing gauge kinetic mixing, I can see SARAH adds a soft term M\lambda_B\lambda_C (where B is the original vector superfield). Now, in the gauge sector of the theory, there are terms as:

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\delta*(\lambda_C\sigma^{\mu}\partial_{\mu}\bar{\lambda}_B + \lambda_B\sigma^{\mu}\partial_{\mu}\bar{\lambda}_C),

where \delta is the coefficient of gauge kinetic mixing. Does SARAH add those fermionic kinetic mixing terms? (I know SARAH does not write the gauge kinetic mixing in terms of this coefficient but rather in terms of 4 new gauge couplings). I cannot see the effect of those terms in the 6x6 neutralino mass matrix.

Thank you,
Amin

[FStaub]

Hi,

no SARAH doesn't generate these terms. What is does is to modify the gaugino-fermion-sfermion coupling in the same way as the vector-boson coupling to two fermions or scalar. That means

g_a Q(F)_a F_i S^*_i \lambda_a

becomes

g_ab Q(F)_b F_i S^*_i \lambda_b

Cheers,
Florian

[Amin]

Hi Florian,

Thanks for clarifying this. So the effect of the term I am looking for is encoded in g_ab which is the matrix {{g_1, \tilde{g}}, {0, g_BL}} you define in Eq. (4.9) for the B-L model in your paper arXiv:1503.04200 ?

Best,
Amin

[FStaub]

Yes, you can also check https://arxiv.org/abs/1112.4600 which provides more details.

[Amin]

Thanks Florian. I will check the paper.

Best,
Amin