slha-reinit-fix

[smrenna]

applied patch to handle min/max values of resonance masses after multiple reinits.

Explicit checks are made to guarantee that the minimum value sampled for a resonance mass
is below the nominal mass. This is relevant when the slha information is updated in Pythia and
an existing pythia instance is re-initialized.

[cmsbuild]

A new Pull Request was created by @smrenna for branch cms/243.

@aandvalenzuela, @smuzaffar, @cmsbuild, @iarspider can you please review it and eventually sign? Thanks.
@antoniovilela, @rappoccio, @sextonkennedy you are the release manager for this.
cms-bot commands are listed here

[cmsbuild]

cms-bot internal usage

[menglu21]

@cmsbuild please test

[smuzaffar]

Hi, is this change still needed for pythia8 version 243? We already have pythia8 300+ in CMSSW_12 and above

[smuzaffar]

Hi, is this still needed ? If yes then which release cycle

[smrenna]

The patch is needed because some CMSSW releases still use an older version of the 200 series.
We (pythia) do not change our releases, but provide updates. There was a fix in the lastest version of the 200 series, but
CMS does not use that version. Since then, we develop the 300 series!