Sub-string match in hyperscan

Hello,
[This is a query and not a bug report]

I have a text like this:
1/1 53 f(2)/p(c)/gmail:login=beta@gmail.com

And, I am trying to find a match for this pattern: "beta@gmail.com"
But hyperscan doesn't return a match for this pattern!

However, if I modify my pattern to be searched as ".*beta@gmail.com" then hyperscan does return a match!

Is this behavior expected?
Is it possible to set any flag in hyperscan to match the exact sub-string("beta@gmail.com" in this case) without any regex in the pattern?

Regards.