There's different ways to do, to the letter, what you're asking for. The most common technique is to have one (or more) of the ARPs as a "Mute" arpeggio. If your time signature is 4/4 then you would pick "Mute 4/4". What this does is stops the ARP from sounding notes - but still keeps the ARP running so when you switch to a non-"Mute" ARP - the ARP will start in time. So it keeps the ARP going - but just doesn't play any notes.

I'm also assuming you mean you want to play other tracks with a pulse - in time (in tempo) but just without the bass or drums playing. In other words you're suggesting "without the beat" means "without drums and bass". And not that you want the other tracks to be in some free time without tempo.

This tutorial: https://www.yamahasynth.com/modx-category/mastering-modx-an-fm-x-exploration-part-iv

Has a reasonable section on how ARP Select relates to PARTs relates to using "Mute X/Y" (like Mute 4/4) arpeggio types.

And how to look at the high-level view as well as drill down to the individual PART and setup the ARPs so you get what you want.

Even though the tutorial is FM - the ARP section applies, for the most part, to any PART type.