New bounds on dark matter coupling from a global network of optical atomic clocks

We report on the first Earth-scale quantum sensor network based on optical atomic clocks aimed at dark matter (DM) detection. Exploiting differences in the susceptibilities to the fine-structure constant of essential parts of an optical atomic clock, i.e., the cold atoms and the optical reference cavity, we can perform sensitive searches for DM signatures without the need for real-time comparisons of the clocks. We report a two orders of magnitude improvement in constraints on transient variations of the fine-structure constant, which considerably improves the detection limit for the standard model (SM)-DM coupling. We use Yb and Sr optical atomic clocks at four laboratories on three continents to search for both topological defect and massive scalar field candidates. No signal consistent with a DM coupling is identified, leading to considerably improved constraints on the DM-SM couplings.

[Aarskog's syndrome (facial-digital-genital syndrome). Study of a family (author's transl)]

A case of Aarskog syndrome in a 6-years old boy is reported. The patient showed clinical pictures typical of the syndrome: characteristic dysmorphic facies, palpebral ptosis, brachyfalangism, abnormality of the scrotum. Minimal stigmata and clinodactyly of 5th finger were present in a sister. Isolated bilateral clinodactyly was found in other 4 members of the family. The significance of this sign in the context of the syndrome has been discussed. Unusual dermatoglyphic patterns were present in the proband, mother and sister.