Answer by Dennis Williamson for Tmux: equivalent command to screen -d -m -S session_name

The new-session command with the -d option is similar to the -d -m option in screen. The -s option corresponds to the -S option in screen. Note that -d and -s are options to the new-session command rather than to tmux itself.

tmux new-session -d -s session_name '/root/script'