Journal of High Energy Physics (Apr 2018)

Heavy-flavor parton distributions without heavy-flavor matching prescriptions

  • Valerio Bertone,
  • Alexandre Glazov,
  • Alexander Mitov,
  • Andrew S. Papanastasiou,
  • Maria Ubiali

DOI
https://doi.org/10.1007/JHEP04(2018)046
Journal volume & issue
Vol. 2018, no. 4
pp. 1 – 32

Abstract

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Abstract We show that the well-known obstacle for working with the zero-mass variable flavor number scheme, namely, the omission of O1 $$ \mathcal{O}(1) $$ mass power corrections close to the conventional heavy flavor matching point (HFMP) μ b = m, can be easily overcome. For this it is sufficient to take advantage of the freedom in choosing the position of the HFMP. We demonstrate that by choosing a sufficiently large HFMP, which could be as large as 10 times the mass of the heavy quark, one can achieve the following improvements: 1) above the HFMP the size of missing power corrections Om $$ \mathcal{O}(m) $$ is restricted by the value of μ b and, therefore, the error associated with their omission can be made negligible; 2) additional prescriptions for the definition of cross-sections are not required; 3) the resummation accuracy is maintained and 4) contrary to the common lore we find that the discontinuity of α s and pdfs across thresholds leads to improved continuity in predictions for observables. We have considered a large set of proton-proton and electron-proton collider processes, many through NNLO QCD, that demonstrate the broad applicability of our proposal.

Keywords