• Physics 15, s169
A superconducting nanowire detector locations new bounds on how a hypothetical light-weight darkish matter particle interacts with electrons.
Looking for light-weight darkish matter particles requires detectors with a lot decrease sign thresholds than conventional experiments. This requirement has prompted novel detection strategies, together with probing the faint interactions that happen between sub-MeV particles and electrons. In a 180-hour-long experiment, Yonit Hochberg of the Hebrew College of Jerusalem and her colleagues show a tool that distinguishes hypothetical sub-MeV darkish matter from background noise with report sensitivity . Their experiment locations the strongest constraints but on interactions between light-weight darkish matter and common matter.
Hochberg and her colleagues etched an array of nanowires in a 7-nm-thick tungsten-silicide movie to supply a superconducting nanowire single-photon detector, a sensor that’s delicate to extraordinarily small power inputs. When power above some threshold is deposited on a superconducting nanowire, the wire briefly turns into a daily conductor, leading to a voltage pulse.
The crew circulated a hard and fast present by their gadget and sealed it in a light-tight field for 180 hours. They counted 4 voltage pulses, every comparable to a deposited power of at the very least 0.73 eV. Absent another detectable power supply, these darkish counts could possibly be attributed to cosmic-ray-generated muons or high-energy particles excited by radioactive decay.
To differentiate such background sources from interactions between sub-MeV darkish matter and electrons, the researchers used an method that relates the darkish matter interplay charge to the gadget’s dielectric properties. Particularly, when power is deposited by darkish matter, electrons within the materials must be rearranged in a selected approach, affecting the wire’s electromagnetic area. The crew’s calculations present higher bounds on electron scattering and absorption charges with sub-MeV and sub-eV particles. The researchers say that these constraints enhance on earlier limits by a number of orders of magnitude.
Rachel Berkowitz is a Corresponding Editor for Physics Journal based mostly in Vancouver, Canada.
- Y. Hochberg et al., “New constraints on darkish matter from superconducting nanowires,” Phys. Rev. D 106, 112005 (2022).