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Factorization for substructures of boosted Higgs jets

Joshua Isaacson; Hsiang-nan Li; Zhao Li; C.-P. YuanSubjects: Physics >> Nuclear Physics

We present a perturbative QCD factorization formula for substructures of an energetic Higgs jet, taking the energy profile resulting from the?H→bb??decay as an example. The formula is written as a convolution of a hard Higgs decay kernel with two?b-quark jet functions and a soft function that links the colors of the two?b?quarks. We derive an analytical expression to approximate the energy profile within a boosted Higgs jet, which significantly differs from those of ordinary QCD jets. This formalism also extends to boosted?W?and?Z?bosons in their hadronic decay modes, allowing an easy and efficient discrimination of fat jets produced from different processes. |

Subjects: Physics >> Nuclear Physics

We study?S-wave resonance contributions to the?B0(s)→J/ψπ+π??and?Bs→π+π??+???decays in the perturbative QCD (PQCD) framework by introducing two-hadron distribution amplitudes for final states. The Breit-Wigner formula for the?f0(500),?f0(1500)?and?f0(1790)?resonances and the Flatt\'e model for the?f0(980)resonance are adopted to parameterize the time-like scalar form factors in the two-pion distribution amplitudes, which include both resonant and nonresonant contributions. The resultant branching fraction and differential branching fraction in the pion-pair invariant mass for each resonance channel are consistent with experimental data. The determined?S-wave two-pion distribution amplitudes, containing the information of both resonant and nonresonant rescattering phases, can be employed to predict direct CP asymmetries of other three-body hadronic?B?meson decays in various localized regions of two-pion phase space. |

[1 Pages/ 2 Totals]