Introduction

The AlpgenInterface is undergoing a complete restructuring, according to the new guidelines for GeneratorInterfaces. This page documents this restructuring

New Features

Validation

• W + jets
  • Basic mother-daughter relations validation.

Useful bits

• The PYUPRE subroutine:

C...PYUPRE
C...Rearranges contents of the HEPEUP commonblock so that
C...mothers precede daughters and daughters of a decay are
C...listed consecutively.

FORTRAN routines

Here we describe the FORTRAN routines responsible for the matching in standalone matching.

UPINIT routine

• I/O
• Call ALSHCD - returns "PYT"
• I/O
  • Read until "****"
  • Read IHRD
  • Read six masses (mc, mb, mt, mw, mz, mh)
  • Read key-value pairs (PARVAL[NTMP] array)
  • Read until "****"
  • Read xsec, xsec_error, number of unw events, luminosity
• Call AHSPAR to setup parameters - this sets EBEAM.
  • This sets every parameter except IHRD, the masses and the jet clustering parameters.
• PBEAM1=DBLE(EBEAM), PBEAM2=DBLE(EBEAM), IH1=1 --> these are tramp variables to set up HEPRUP later.
• Call PDFCONVH (what does it do?)
• Call ALSHCD
• Prepares INORAD
• Gets jet matching criteria
• Sets up the HEPRUP
• Calls ALSHIN (passes the six masses to PYTHIA)
• Sets LPRUP (originally it was 661, now it has a meaning).

• UPINIT.odg: UPINIT

UPVETO routine

-- ThiagoTomei - 11 Feb 2009