New Exclusion Limits for Dark Gauge Forces from Beam-Dump Data
Johannes Blümlein, Jürgen Brunner
TL;DR
The paper reanalyzes U70 proton beam-dump data to set exclusion limits on dark U(1) gauge bosons γ'. It develops a production model where γ' is produced in π^0 decays and computes the γ' flux from π^0 yields modeled with empirical pp cross sections. It obtains new mass–coupling exclusions for m_γ' < m_π^0 and a range of ε values, extending accelerator bounds in the MeV–GeV region. The work demonstrates how archival beam-dump data can constrain hidden-sector gauge forces and informs future experimental searches.
Abstract
We re-analyze proton beam dump data taken at the U70 accelerator at IHEP Serpukhov with the $ν$-calorimeter I experiment in 1989 to set mass-coupling limits for dark gauge forces. The corresponding data have been used for axion and light Higgs particle searches in Refs. before. We determine new mass and coupling exclusion bounds for dark gauge bosons.