Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, USA.
Institut Max von Laue Paul Langevin, 71 avenue des Martyrs, F-38042 Grenoble Cedex 9, France.
Phys Rev Lett. 2018 Aug 10;121(6):061801. doi: 10.1103/PhysRevLett.121.061801.
The observation of neutron stars with masses greater than one solar mass places severe demands on any exotic neutron decay mode that could explain the discrepancy between beam and bottle measurements of the neutron lifetime. If the neutron can decay to a stable, feebly interacting dark fermion, the maximum possible mass of a neutron star is 0.7M_{⊙}, while all well-measured neutron star masses exceed one M_{⊙}. The existence of 2M_{⊙} neutron stars further indicates that any explanation beyond the standard model for the neutron lifetime puzzle requires dark matter to be part of a multiparticle dark sector with highly constrained interactions. Beyond the neutron lifetime puzzle, our results indicate that neutron stars provide unique and useful probes of GeV-scale dark sectors coupled to the standard model via baryon-number-violating interactions.
观测质量大于一个太阳质量的中子星，对任何奇异的中子衰变模式提出了严格的要求，这种模式可以解释束流和瓶中测量的中子寿命之间的差异。如果中子可以衰变为稳定的、弱相互作用的暗费米子，那么中子星的最大质量可能是 0.7M⊙，而所有经过精确测量的中子星质量都超过 1M⊙。2M⊙ 中子星的存在进一步表明，任何超出标准模型的对中子寿命之谜的解释，都需要暗物质成为一个具有高度受限相互作用的多粒子暗物质部分。除了中子寿命之谜之外，我们的结果还表明，中子星为通过破坏重子数的相互作用与标准模型耦合的 GeV 尺度暗物质部分提供了独特而有用的探针。
