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SUMMARY:ZOOM Yao Ma
DTSTART;VALUE=DATE-TIME:20200702T140000Z
DTEND;VALUE=DATE-TIME:20200702T150000Z
DTSTAMP;VALUE=DATE-TIME:20200707T124735Z
UID:indico-event-2413@cern.ch
DESCRIPTION:Title: A Forest-based Infrared Subtraction for Wide-angle Scat
tering\nAbstract: For any hard QCD amplitude with massless partons\, infra
red (IR) singularities arise from pinches in the complex planes of loop mo
menta\, called pinch surfaces. To organize and study their leading behavio
rs in the neighborhoods of these surfaces\, we can construct approximation
operators for collinear and soft singularities. In my talk\, I will devel
op a BPHZ-like forest formula to subtract the IR singularities systematica
lly. A related analysis has been carried out by Collins for the back-to-ba
ck Sudakov form factors\, and is generalized here to any wide-angle kinema
tics with an arbitrary number of external momenta. After a brief introduct
ion to Minkowskian IR divergences in momentum space\, I will first illustr
ate that the approximations yield much richer IR structures than those of
an original amplitude\, then construct the forest formula and prove that a
ll the singularities appearing in its subtraction terms cancel pairwise. F
inally\, with the help of this forest formula\, the full amplitude can be
reorganized into a factorized expression. (Password to access the Video re
cording: 6b$B37x3)\n\nhttps://indico.nikhef.nl/event/2413/
LOCATION:Nikhef
URL:https://indico.nikhef.nl/event/2413/
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