Hi Florian,

I am trying to study some inplications of a leptonic SSB. The model, due the leptonic SSB, have majorons particles and SPheno all the time calculate a mass to this particles (a small one and most of the time a negative mass). I was wondering if have a special way to implement this kind of particle.

PS.: My toy model was the MSSM with sneutrino having a vev.

Any help would be much appreciated.

Geilson

Hi,

How big is the mass? If the mass squared is O(10^-10), It might just be a numerical zero.

Cheers
Florian

Sorry for the late replay.

For my surprise isn't that small. I was expected some mass O(10^-(4<->6)) but in general the result is a few GeV or negative ones. I already double check all the model to see if I was doing something wrong but I can't find nothing.



Cheers,
Geilson

Hmm... Can you try to turn off the one- and two-loop corrections to the masses to see at which loop level the masses appear?

Cheers
Florian

This values are only tree level calculation and because this I am worried... If you want I can send you the model and the SPheno output (take some time here) or the LesHouches file with the compiled SPheno or both.

Cheers,
Geilson

Okay, in that case I would need to check the model files. However, that might take some days until I have time.

Cheers
Florian

No problem. I will send to your email because I will include the SPheno output.
Thanks a lot for your time.


Cheers,
Geilson

Hi,

I took a quick look and could at least further pin down the problem: the origin of the negative masses are the gauge fixing terms. In Landau gauge everything looks okay. This is also obvious from the mass matrix in Mathematica when you plugin in the solutions of the tadpoles: the last three entries on the diagonal are proportional to RXi.
However, I'm not sure what the exact reason for this is. If there is a bug in the derivation of the gauge fixing terms or if there is an issue with the model implementation. Two observations/questions: why is the Ah matrix block diagonal, i.e. is there any reason why the pseudo-scalar sneutrinos shouldn't mix with the other states? And is it correct that the left-sneutrino don't get a VEV? Sorry, I'm not very familiar with these 331 models.

Cheers,
Florian

Yep in the Landau gauge every was working fine looking at the mass matrix generate by SARAH. I will try SARAH 4.10.2 because in this version another 331 version worked fine.

1) The pseudo-scalar sneutrinos will be the marjorons particles because the lepton number is spontaneous broken and we have used a discrete symmetry to exclude some terms in the superpotential that could force other mixing. I am trying to implement the small one first and see what happen to pass to the complete one later.

2) In general yes but having the discrete symmetry in the superpotential if they get a vev the tadpole equation for this state are proportional to this vev and and having all gauge symmetry already broken there are no good reason to vev be not be zero.

Many thanks to check the model and best regards,
Geilson