Science does not need to adopt a whole new language because the rest of popular culture is ambiguous.
It has two meanings, the biological sex of an organism and the biological reproduction of that organism.
The other alternative would have been them doing some experimental fucking next to the mice to see what happens. Such a paper would undoubtedly have been titled differently.
"Experimenters' (possessive) sex" : so, their biological sex is the only thing they can posses in this sentence. They can't "possess" sexual reproduction in this context, that would not make any sense. This is just simple grammar.
Gender would also make zero sense because this is not an article about gender.
I can understand the confusion if English isn't your first language but outside of that it's very clear.
2: capable of being understood in two or more possible senses or ways
Thanks to grammar, we are literally incapable of understanding "sex" in this context to mean anything other than biological sex. I can't believe I'm having to explain this multiple times.
The only argument people are making is that they lack the reading comprehension to understand the sentence correctly.
And unless there's the possibility that people are fucking in front of the mice, there's no ambiguity here.