The low-energy U(1)_B−L gauge symmetry is well-motivated as part of beyond Standard Model physics related to neutrino mass generation. We show that a light B − L gauge boson Z′ and the associated U(1)_B−L-breaking scalar φ can both be effectively searched for at high-intensity facilities such as the near detector complex of the Deep Underground Neutrino Experiment (DUNE). Without the scalar φ, the Z′ can be probed at DUNE up to mass of 1 GeV, with the corresponding gauge coupling g_BL as low as 10⁻⁹. In the presence of the scalar φ with gauge coupling to Z′, the DUNE capability of discovering the gauge boson Z′ can be significantly improved, even by one order of magnitude in g_BL, due to additional production from the decay φ → Z′Z′. The DUNE sensitivity is largely complementary to other long-lived Z′ searches at beam-dump facilities such as FASER and SHiP, as well as astrophysical and cosmological probes. On the other hand, the prospects of detecting φ itself at DUNE are to some extent weakened in presence of Z′, compared to the case without the gauge interaction.

低能 U(1) _BL规范对称性作为与中微子质量产生相关的超标准模型物理学的一部分受到了很好的激励。我们表明，在深地下中微子实验的近探测器复合体等高强度设施中，可以有效地搜索到一个轻的B−L规范玻色子Z'和相关的 U(1) _B−L破坏标量φ。沙丘）。在没有标量φ 的情况下，Z ' 可以在 DUNE 处探测到质量高达 1 GeV，相应的规范耦合g _BL低至 10 ^{- 9}。在存在标量φ 时，与规范耦合Z '，DUNE 发现规范玻色子Z ' 的能力可以显着提高，即使是g _BL的一个数量级，由于衰变φ → Z ' Z ' 的额外产生。DUNE 灵敏度在很大程度上是对其他长寿命Z ' 搜索的补充，例如 FASER 和 SHiP 以及天体物理和宇宙学探测器。另一方面，与没有规范相互作用的情况相比，在存在Z ' 的情况下，在 DUNE检测φ本身的前景在某种程度上减弱。