paper

Phenomenological Study of Heavy Hadron Lifetimes

arXiv:1807.00916 · doi:10.1007/JHEP11(2018)014

Abstract

The lifetimes of bottom and charmed hadrons are analyzed within the framework of the heavy quark expansion (HQE). Lifetime differences arise from the spectator effects such as weak -annihilation and Pauli interference. Spectator effects originating from dimension-7 four-quark operators are derived. Hadronic matrix elements of four-quark operators are parameterized in a model-independent way. Using the dimension-6 bag parameters recently determined from HQET sum rules and the vacuum insertion approximation for meson matrix elements of dimension-7 operators, the calculated meson lifetime ratios and are in excellent agreement with experiment. Likewise, based on the quark model evaluation of baryon matrix elements, the resulting baryon lifetime ratios , , and the lifetime ratio also agree well with the data. Contrary to the bottom hadron sector where the HQE in works well, the HQE to fails to give a satisfactory description of the lifetimes of both charmed mesons and charmed baryons. This calls for the subleading corrections to spectator effects. The relevant dimension-7 spectator effects are in the right direction for explaining the large lifetime ratio of .

41 pages, 3 figures, improved version, to appear in JHEP

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