tunable ratio of ccbar and bbbar for embedding

[wuctlby]

Hi @xinyepeng , @gluparel , @stefanopolitano , @zhangbiao-phy , and @mfaggin ,

As discussed in the previous D2H meeting, I implemented a new generator with a tunable ratio of ccbar and bbbar for embedding the HF event into the signal event and the corresponding ini file, as well as the modification of 0.36000 0 2212 311 ### Λc+ -> p K0S 1.59% ==> 1 0.36000 0 2212 310 ### Λc+ -> p K0S 1.59% in the Pythia config file.

Specifically,

• generator_pythia8_embed_hf.C
  -- new hf_generators enum GapHFRatio to trigger GeneratorPythia8GapTriggeredHF with a given quarkPdgList
  -- BuildQuarkListFromBOverC, which builds the quarkPdgList from bOverCRatio
  -- GeneratorPythia8EmbedHFRatio, which accepts the new parameter bOverCRatio for generating the quarkPdgList. For example, if bOverCRatio=3, the BuildQuarkListFromBOverC will generate a list [5,5,5,4], which will embed the ccbar and bbbar in the order of this list

Please let me know if you have any comments or suggestions. Thanks a lot!

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[mfaggin]

In principle this should work in pythia, but did you check that this works?
The physics wants that only 4122:addChannel = 1 0.36000 0 2212 311 is correct, since K0, K0bar are the only states with a well-defined strangeness content, that materialize as K0s or K0L only in decay.
Did you check that the correct and expected decays are present, i.e. the fact that we have Lc decaying into p and K0s with K0s decaying in 2 pions?

[wuctlby]

Yes, I did a private test, and it works.
I checked the decay channels produced in one of the kinematic files, and they look good.

Then I further checked the decay of produced K0s, as follows:
Found K(S)0 daughters for Lambdac+ decay: 111 (#pi^{0}) 111 (#pi^{0})
Found K(S)0 daughters for Lambdac+ decay: 211 (#pi^{+}) -211 (#pi^{-})

[mfaggin]

thanks @wuctlby , I left a couple of comments with a few suggestions and a question. Thank you!