# $B\to D^{(*)}\tau\nu_\tau$ in the 2HDM with an anomalous $\tau$ coupling

## TL;DR

This paper investigates the $R(D^{(*)})$ anomalies in B meson decays within the two-Higgs-doublet model, introducing an anomalous tau coupling to better fit experimental data from BaBar, Belle, and LHCb.

## Contribution

It proposes a modified 2HDM with an anomalous tau coupling to explain the $R(D^{(*)})$ puzzle, showing all model types fit data similarly and improving fit with normalized ratios.

## Key findings

- All four types of the model yield similar minimum chi-squared values.
- Normalized $R(D^{(*)})$ with $B o au
u$ data reduces chi-squared significantly.
- The anomalous tau coupling provides a better fit to experimental results.

## Abstract

The puzzle of $R(D^{(*)})$ associated with $B\to D^{(*)}\tau\nu$ decay is addressed in the two-HIggs-doublet model. An anomalous coupling of $\tau$ to the charged Higgs is introduced to fit the data from BaBar, Belle, and LHCb. It is shown that all of the four types of the model yield similar values of the minimum $\chi^2$. Also shown is that the newly normalized $R(D^{(*)})$ with the branching ratio of $B\to\tau\nu$ decay exhibits much smaller minimum $\chi^2$.