Solutions to R-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msub><mml:mrow><mml:mi>R</mml:mi></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mo>⁎</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:msub></mml:math> in light of Belle 2019 data
Ashutosh Kumar Alok, Dinesh Kumar, Suman Kumbhakar, S. Uma Sankar
Abstract
Earlier this year, the Belle collaboration presented their new measurements of RD and RD⁎ using a new method. These measurements are consistent with the Standard Model predictions, whereas the global averages of the earlier measurements had a 4.1σ discrepancy. With the inclusion of the new data in the global averages, the discrepancy comes down to 3.1σ. In this work, we study the new physics solutions to the RD-RD⁎ anomaly allowed by the reduction in the discrepancy. Among the four fermion operators, which arise through a single particle exchange, only the (V−A) operator solution survives. We found three additional solutions with two dis-similar operators. The branching ratio of Bc→τν¯ is powerful discriminant between these four allowed solutions.