Figure 4: Experimental constraints on the left-handed coupling, |V_ub^L| and the fractional right-handed coupling, ε_R.

Whereas the overlap of the 68% confidence level bands for the inclusive¹⁴ and exclusive⁷ world averages of past measurements suggested a right-handed coupling of significant magnitude, the inclusion of the LHCb |V_ub| measurement does not support this.