2010.07.23 PyTune comparison with photon candidates: Perugia0 vs. Pro-PT0

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Data samples and colour coding

  1. black Pythia QCD Monte-Carlo with Pro-Pt0 tune (pytune=329),   partonic pt 9-15
  2. red    Pythia QCD Monte-Carlo with Perugia0 tune (pytune=320), partonic pt 9-15

Event selection

Ran full Pythia+GSTAR simulation and require at least one
reconstucred  EEMC photon candidate in the gamma Maker.

Figure 1:
Left: Reconstructed photon candidate transverse momentum (no normalization factor applied)
Right: ratio of Pro-Pt0/Perugia0 simulations (solid Line: "a+b*x" fit to ratio)
Event selections: require at least one reconstucred EEMC photon candidate

Figure 2:
Same as in Fig. 1 with different event selection criteria:
L2E-gamma, |v_z| < 120cm, at least one EEMC gamma candidate


Pytune parameters comparison table

pytune(320) Perugia 0
P. Skands, Perugia MPI workshop October 2008
and T. Sjostrand & P. Skands, hep-ph/0408302
CR by M. Sandhoff & P. Skands, in hep-ph/0604120
LEP parameters tuned by Professor

pytune(329) Pro-pT0
See T. Sjostrand & P. Skands, hep-ph/0408302
and M. Sandhoff & P. Skands, in hep-ph/0604120
LEP/Tevatron parameters tuned by Professor

Red text indicates the parameter which are different between tunes

Parameter Perugia 0 Pro-pT0 Parameter description
MSTP(51) 7  7 PDF set
MSTP(52) 1 1 PDF set internal (=1) or pdflib (=2)
MSTP(64) 3 2 ISR alphaS type
PARP(64) 1.0000 1.3000 ISR renormalization scale prefactor
MSTP(67) 2 2 ISR coherence option for 1st emission
PARP(67) 1.0000 4.0000 ISR Q2max factor
MSTP(68) 3 3 ISR phase space choice & ME corrections
(Note: MSTP(68) is not explicitly (re-)set by PYTUNE)
MSTP(70) 2 2 ISR IR regularization scheme
MSTP(72) 1 0 ISR scheme for FSR off ISR
PARP(71) 2.0000 2.0000 FSR Q2max factor for non-s-channel procs
PARJ(81) 0.2570 0.2570 FSR Lambda_QCD scale
PARJ(82) 0.8000 0.8000 FSR IR cutoff
MSTP(81) 21 21 UE model
PARP(82) 2.0000 1.8500 UE IR cutoff at reference ecm
(Note: PARP(82) replaces PARP(62).)
PARP(89) 1800.0000 1800.0000 UE IR cutoff reference ecm
PARP(90) 0.2600 0.2200 UE IR cutoff ecm scaling power
MSTP(82) 5 5 UE hadron transverse mass distribution
PARP(83) 1.7000 1.8000 UE mass distribution parameter
MSTP(88) 0 0 BR composite scheme
MSTP(89) 1 1 BR colour scheme
PARP(79) 2.0000 1.1800 BR composite x enhancement
PARP(80) 0.0500 0.0100 BR breakup suppression
MSTP(91) 1 1 BR primordial kT distribution
PARP(91) 2.0000 2.0000 BR primordial kT width <|kT|>
PARP(93) 10.0000 7.0000 BR primordial kT UV cutoff
MSTP(95) 6 6 FSI colour (re-)connection model
PARP(78) 0.3300 0.1700 FSI colour reconnection strength
PARP(77) 0.9000 0.0000 FSI colour reco high-pT dampening streng
MSTJ(11) 5 5 HAD choice of fragmentation function(s)
PARJ(21) 0.3130 0.3130 HAD fragmentation pT
PARJ(41) 0.4900 0.4900 HAD string parameter a
PARJ(42) 1.2000 1.2000 HAD string parameter b
PARJ(46) 1.0000 1.0000 HAD Lund(=0)-Bowler(=1) rQ (rc)
PARJ(47) 1.0000 1.0000 HAD Lund(=0)-Bowler(=1) rb