## Friday, February 12, 2021 ... //

### PandaX-II seems to slightly strengthen XENON1T's hints of dark matter particles

The recent Chinese 3D remake of the legendary cute Czech Little Mole features a new, bigger friend of the Central and Eastern Europe, I mean of the little mole, namely the People's Republic of China, I mean a big fat panda. ;-) This was the first episode among many.

This blog post is very brief because I don't think it's a good investment of time to write full-blown texts. But as you know, the hints of any new particle behind the Standard Model are extremely weak or almost non-existent.

Last June, Elena Aprile and her XENON1T folks (yes, one ton of xenon in the detector) saw some

Excess Electronic Recoil Events in XENON1T
(not to be confused with nuclear recoil events that they also like to observe) which represented the excess around 3.0-3.5 sigma above the background.

It may be explained by the boring tritium junk or by the exciting axions or magnetic neutrinos. See a July paper that analyzes the excess and tries to explain it.

Now, a similar Chinese experiment
Search for Light Dark Matter-Electron Scatterings in the PandaX-II Experiment
which also uses a xenon detector failed to make a clear discovery in either way but remain compatible with the exciting hypotheses that include new particles (which is probably a dark matter particle). It's a nearly neutral result but I think that the Panda could have falsified the models by now but I didn't, so I call it a slight strengthening of the exciting hints.

Read e.g. Physics World for a fresh popular summary of these developments.