Search for the Dark Photon and the Dark Higgs Boson at Belle

	Search for the Dark Photon and the Dark Higgs Boson at Belle
	Belle Collaboration
刊名	PHYSICAL REVIEW LETTERS
	2015
卷号	114 页码:211801
英文摘要	The dark photon A' and the dark Higgs boson h' are hypothetical constituents featured in a number of recently proposed dark sector models. Assuming prompt decays of both dark particles, we search for their production in the so-called Higgstrahlung channel e(+)e(-) -> A'h', with h' -> A'A'. We investigate ten exclusive final states with A' -> e(+)e(-), mu(+)mu(-), or pi(+)pi(-) in the mass ranges 0.1 GeV/c(2) < m(A') < 3.5 GeV/c(2) and 0.2 GeV/c(2) < m(h') < 10.5 GeV/c(2). We also investigate three inclusive final states 2(e(+)e(-))X, 2(mu(+)mu(-))X, and (e(+)e(-))(mu(+)mu(-))X, where X denotes a dark photon candidate detected via missing mass, in the mass ranges 1.1 GeV/c(2) < m(A') < 3.5 GeV/c(2) and 2.2 GeV/c(2) < m(h') < 10.5 GeV/c(2). Using the entire 977 fb(-1) data set collected by Belle, we observe no significant signal. We obtain individual and combined 90% credibility level upper limits on the branching fraction times the Born cross section, B x sigma(Born), on the Born cross section sigma(Born), and on the dark photon coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, alpha(D) x epsilon(2). These limits improve upon and cover wider mass ranges than previous experiments. The limits from the final states 3(pi(+)pi(-)) and 2(e(+)e(-))X are the first placed by any experiment. For alpha(D) equal to 1/137, m(h') < 8 GeV/c(2), and m(A') < 1 GeV/c(2), we exclude values of the mixing parameter epsilon above similar to 8 x 10(-4).
学科主题	Physics
类目[WOS]	Physics, Multidisciplinary
收录类别	SCI ; EI
WOS记录号	WOS:000355101300008
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/228484]
专题	高能物理研究所_实验物理中心
推荐引用方式 GB/T 7714	Belle Collaboration. Search for the Dark Photon and the Dark Higgs Boson at Belle[J]. PHYSICAL REVIEW LETTERS,2015,114:211801.
APA	Belle Collaboration.(2015).Search for the Dark Photon and the Dark Higgs Boson at Belle.PHYSICAL REVIEW LETTERS,114,211801.
MLA	Belle Collaboration."Search for the Dark Photon and the Dark Higgs Boson at Belle".PHYSICAL REVIEW LETTERS 114(2015):211801.