Progress on the Pythia 8 event generator

BSM physics 3: Hidden Valley (Secluded Sector) – 2
⋆ Hidden Valley particles may remain invisible, or . . .
⋆ Broken U(1): γ v acquire mass, radiated γ v sdecayback
γ v → γ → ff with BRs as photon (⇒ lepton pairs!)
⋆ SU(N): hadronizationinhiddensector,withfullstringfragmentation,
permitting up to 8 different q v flavours and 64 q v q v mesons,
but for now assumed degenerate in mass, so only distinguish
– off-diagonal, flavour-charged, stable & invisible
–diagonal,candecaybackq v q v → ff
Even when tuned to same average activity, hope to separate U(1) and SU(N):
#(N v )
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
Ab
non-Ab.
0 2 4 6 8 10
N v
#(cos θ)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Ab.
non-Ab.
0
0 0.5 1 1.5 2 2.5 3
Torbjörn Sjöstrand <strong>Progress</strong> on the Pythia 8 event generator slide 37/46
cos θ