title: HF(v' = 3) forward scattering in the F + H2 reaction: shape resonance and slow-down mechanism.
abstract: Crossed molecular beam experiments and accurate quantum dynamics calculations have been carried out to address the long standing and intriguing issue of the forward scattering observed in the F + H(2) --> HF(v' = 3) + H reaction. Our study reveals that forward scattering in the reaction channel is not caused by Feshbach or dynamical resonances as in the F + H(2) --> HF(v' = 2) + H reaction. It is caused predominantly by the slow-down mechanism over the centrifugal barrier in the exit channel, with some small contribution from the shape resonance mechanism in a very small collision energy regime slightly above the HF(v' = 3) threshold. Our analysis also shows that forward scattering caused by dynamical resonances can very likely be accompanied by forward scattering in a different product vibrational state caused by a slow-down mechanism.
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China.
authors.forename: Xingan
authors.initials: X
authors.lastname: Wang
authors.forename: Wenrui
authors.initials: W
authors.lastname: Dong
authors.forename: Minghui
authors.initials: M
authors.lastname: Qiu
authors.forename: Zefeng
authors.initials: Z
authors.lastname: Ren
authors.forename: Li
authors.initials: L
authors.lastname: Che
authors.forename: Dongxu
authors.initials: D
authors.lastname: Dai
authors.forename: Xiuyan
authors.initials: X
authors.lastname: Wang
authors.forename: Xueming
authors.initials: X
authors.lastname: Yang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Sun
authors.forename: Bina
authors.initials: B
authors.lastname: Fu
authors.forename: Soo-Y
authors.initials: SY
authors.lastname: Lee
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Dong H
authors.initials: DH
authors.lastname: Zhang