Hi,

Recently I have been studying the vacuum stability of higgs and stau scalar potentials in MSSM with Vevacious. However I find that most parameter points can go through Vevacious but there are still some parameter points that can't be calculated successfully by Vevacious when I turn on thermal calculations. The error is as the followings:

tunnelingCalculator.npoints being given 137
falseVacuumArray = [0. 0. 0. 0.]
trueVacuumArray = [ 93.46248299 -3567.76895125 -3509.70633295 4699.95658229]
Traceback (most recent call last):
File "./Vevacious.py", line 197, in <module>
dsbEvaporationTemperature )
File "/home/pengbo/secondproject/6vevscan/test/VevaciousParameterDependent.py", line 1508, in FindOptimalTunnelingTemperature
thermalNotQuantum = True )
File "/home/pengbo/secondproject/6vevscan/test/VevaciousParameterDependent.py", line 1248, in CalculateAction
maxiter = outerLoopMaxDeformations )
File "/home/pengbo/VEVACIOUS/CosmoTransitions-2.0a2/cosmoTransitions/pathDeformation.py", line 935, in fullTunneling
profile1D = tobj.findProfile(**tunneling_findProfile_params)
File "/home/pengbo/VEVACIOUS/CosmoTransitions-2.0a2/cosmoTransitions/tunneling1D.py", line 700, in findProfile
rf, yf, ctype = self.integrateProfile(r0, y0, *integration_args)
File "/home/pengbo/VEVACIOUS/CosmoTransitions-2.0a2/cosmoTransitions/tunneling1D.py", line 504, in integrateProfile
x = optimize.brentq(lambda x: f(x)[1], 0,1)
File "/usr/local/lib/python2.7/dist-packages/scipy/optimize/zeros.py", line 510, in brentq
r = _zeros._brentq(f,a,b,xtol,rtol,maxiter,args,full_output,disp)
ValueError: f(a) and f(b) must have different signs

Minimizing the one-loop potential, calculating the tunneling time or its upper bound, and printing the results took 19.2795 seconds.

Warning! "./74.out" was not produced!

If I turn off thermal calculations they can go through it and they are all long lived points. I have tried to modify input settings or relevant programs but all methods failed. Do you know how to solve this problem? Thank you very much!

Best Wishes!
Bo

Dear Bo Peng,

as mentioned in our direct correspondence, I do not know exactly what the problem is, but suspect that the potential is too shallow for the computer code to resolve a barrier sufficiently.

Investigating the potential at a specific non-zero T might give some insights (as in, hacking the Vevacious.py code to just print out potential depths at a set of points where you put in values for T and the scalar fields, maybe in a grid around the minima, maybe at regular intervals in a straight line between the minima, and so on). Sometimes it's just that the algorithm used by CosmoTransitions just does not work.

Regards,
Ben

Hi,

it seems that something goes wrong with your runs: One of these vacua should the ew one. Thus, Vevacious doesn't find the input minimum. As long as this doesn't work, I won't trust any result.
One possible origin might be that you use different loop levels for the parameters and the potential.

Cheers,
Florian

No, there's no problem if that's at a non-zero temperature, as the SU(2)-breaking minimum "evaporates" at a few hundred GeV I think.So Vevacious correctly rolls it to {0, 0, 0, 0}.