QCD corrections at subleading power for inclusive nonleptonic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>b</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:mi>c</mml:mi><mml:mover accent="true"><mml:mro

In this paper we compute the next-to-leading order (NLO) QCD corrections for the inclusive nonleptonic decay rates of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>B</a:mi></a:math> hadrons at subleading power of the heavy quark expansion. In particular, we discuss the coefficient of the chromomagnetic moment parameter <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi>μ</c:mi><c:mi>G</c:mi></c:msub></c:math>, which has a large uncertainty at leading order due to its dependence on the renormalization scale. We find that the renormalization-scale dependence of this coefficient is significantly reduced, thereby reducing the theoretical uncertainty of the coefficient and, consequently, the rates. The sign of the coefficient becomes stable, and we estimate that the NLO corrections will increase the decay rates by around 2%. Published by the American Physical Society 2024