しばらく for a while (usually used in negative connotations)
ひさしぶり for a while (usually used in positive connotations, closer to “long time no see!”)
＃おひさしぶり = honorific way to say ひさしぶり、but usually it is also used in casual speech.
以前お会いしてから、 しばらく ですね～
It’s been a while since we have last met.
Long time no see! How are you today?
#Justin Palmer 1.7.17