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DiscB

DiscB[s,m0,m1]
gives the part of the Passarino-Veltman function containing the plane branch cut, .

Details and OptionsDetails and Options

  • Mathematical function, suitable for both symbolic and numerical manipulation.
  • DiscB is generated by LoopRefine to maintain compact expressions. DiscExpand will replace DiscB with its explicit definition.

  • where is the Källén kinematic function Kallenλ.
  • The scalar Passarino-Veltman function in terms of is given by
  • DiscB[s,m0,m1] has a branch cut discontinuity in the complex plane running from to , and a (non-Landauian) pole at .
  • DiscB[s,m0,m1] is a dimensionless function taking an external invariant-squared , and two masses and as arguments.
  • For special cases, simple expressions are automatically substituted.

ExamplesExamplesopen allclose all

Basic Examples  (4)Basic Examples  (4)

Evaluate numerically:

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The precision of the output tracks the precision of the input:

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Use DiscExpand to insert explict expression:

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Series expansion:

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