3 body decay in NMSSM

Send me model parameters and write for which particle your see it.
Best
   Alexander Pukhov

Dear professor Pukhov,

I considered the decay of ~t2 -> t ~o1 h1 . The parameters are MG1 = 270, MG2 = 1000, MG3 = 1500, Atop = -100.0, Ab=Atau=Amuon=0.0 , All squarks and slepton soft masses = 2500 except MQ3 = 550, MU3=560, Lambda = 0.695, kappa = 0.2, Alambda= -1750.0, Akappa= -30, Mueff= -850.0 and all other non-Z3 invariant terms = 0

This gives M(h1)= 120.43, M(~t2)= 553.76, M(~o1)= 268.3. But CalcHEP calculates the width.

regards,

Jyotiranjan

I see,

In general in CalcHEP models top quark mass Mt it is defined as MtEff(Q).
MtEff is running mass with on scale Q with QCD corrections which reproduce H->t,T decay if Q=MH.
Calculating ~t2 decay CalcHEP substitutes Mt=MtEff(Mass(~t2))l
I guess such Mt<165 and decay ~t2-> t,~o1, h takes place.

You can redefine model and set Mt=Mtp (pole mass) . Then Yukawa couplings will be a little bit wrong.
Alternatively we can keep Yukawa couplings dependent of scale Q, but define mass top as pole mass.
When some problems with gauge invariance are expected, but I don't know at which point.

So, you can redefine Mt parameter in Constraints table as Mtp, or redefine top quark mass in Particles table as Mtp.

Also you can ask CalcHEP to load NMSSMTools decay widths and branchings. To realize this way you have to add one
line in Constraints table which will read decay file generated by NMSSMTools. Something like
rd2 | slhaRead("decay", 1)

It should be done after

rd |slhaRead("spectr", 0)

CalcHEP will not recalculate widths and branchings loaded via SLHA file.

Let me know if you have a problem in realization of one of these ways. I'll reply you fast. Sorry for some delay with previously mails. I was busy with other job.

Best
  Alexander Pukhov

Thank you very much for your detailed answer. Is the input parameter Q SUSY scale or EWSB scale ? Does this Q enters into NMSSMTools that is included inside? Is it okay if I use default value for Q=100 GeV ?

regards,

Jyotiranjan

Q is a user defined parameter which defines scale used for calculation of running masses.
But when CalcHEP calculates withs, it automatically sets Q=Mass of decaying particle.
Q is not passed for NMSSMTools.

Best
   Alexander Pukhov

Thank you very much for your time and clarifications.

regards,

Jyotiranjan

In last version 3.6.24 pole mass of top is used to define open decay channels. But in width calculation the 'running' one is
substituted as before.

Thanks a lot for updating the change.

regards,

Jyotiranjan