Experimental particle physicist here. It's just hard.

I measured the electron's vector coupling to the Z boson at SLAC in the late 1990s, and the answer from that measurement is: we don't know yet - and that's the point.

Thirty years later, the discrepancy between my experiment and LEP's hasn't been resolved.

It might be nothing. It might be the first whisper of dark matter or a new force. And the only way to find out is to build the next machine. That's not 'dead', that's science being hard.

My measurement is a thread that's been dangling for decades, waiting to be pulled.