Das ist der HAMMER: consistent new physics interpretations of semileptonic decays
Abstract
Precise measurements of b →c τ ν ¯ decays require large resourceintensive Monte Carlo (MC) samples, which incorporate detailed simulations of detector responses and physics backgrounds. Extracted parameters may be highly sensitive to the underlying theoretical models used in the MC generation. Because new physics (NP) can alter decay distributions and acceptances, the standard practice of fitting NP Wilson coefficients to SMbased measurements of the R (D^{(∗)}) ratios can be biased. The newly developed Hammer software tool enables efficient reweighting of MC samples to arbitrary NP scenarios or to any hadronic matrix elements. We demonstrate how Hammer allows avoidance of biases through selfconsistent fits directly to the NP Wilson coefficients. We also present example analyses that demonstrate the sizeable biases that can otherwise occur from naive NP interpretations of SMbased measurements. The Hammer library is presently interfaced with several existing experimental analysis frameworks and we provide an overview of its structure.
 Publication:

European Physical Journal C
 Pub Date:
 September 2020
 DOI:
 10.1140/epjc/s1005202083040
 arXiv:
 arXiv:2002.00020
 Bibcode:
 2020EPJC...80..883B
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Experiment
 EPrint:
 19 pages, 4 figures, published version