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arXiv · 1306.6553

A Hybrid Scheme for Heavy Flavors: Merging the FFNS and VFNS

A. Kusina·F. I. Olness·I. Schienbein·T. Jezo·K. Kovarik·T. Stavreva·J. Y. Yu
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Abstract

We introduce a Hybrid Variable Flavor Number Scheme for heavy flavors, denoted H-VFNS, which incorporates the advantages of both the traditional Variable Flavor Number Scheme (VFNS) as well as the Fixed Flavor Number Scheme (FFNS). By including an explicit $N_F$-dependence in both the Parton Distribution Functions (PDFs) and the strong coupling constant $\alpha_S$, we generate coexisting sets of PDFs and $\alpha_S$ for $N_F=\{3,4,5,6\}$ at any scale $\mu$, that are related analytically by the $\overline{\text{MS}}$ matching conditions. The H-VFNS resums the heavy quark contributions and provides the freedom to choose the optimal $N_F$ for each particular data set. Thus, we can fit selected HERA data in a FFNS framework, while retaining the benefits of the VFNS to analyze LHC data at high scales. We illustrate how such a fit can be implemented for the case of both HERA and LHC data.

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A. Kusina, F. I. Olness, I. Schienbein, T. Jezo, K. Kovarik, T. Stavreva, J. Y. Yu. 2013-06-27. A Hybrid Scheme for Heavy Flavors: Merging the FFNS and VFNS. https://doi.org/10.1103/physrevd.88.074032

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