That's a very sharp photo!
I think it may be some other form of decoration to each side of the wreath. The wreath ties appear to come to an end, and to left of the helmet it looks like it could be a branch. The thing to the right looks different.
One thing that bothers me about this type of Constantinian helmet is what they are actually meant to be. The other Constantinian helmets seem more clear-cut - the ridge helmet (appropriate to the period) on the VLPPs etc, and the Attic/Praetorian helmet typeically seen on the D2 busts (and also on Arch of Constantine).
I *think* these early helmets, such as on your Sol coin here, are meant to be Corinthian helmets, but its not 100% obvious.
Here's what a real Corinthian helmet looks like - really meant to cover the face:
But normally we see the helmet pushed back to top of head, as worn by Athena:
When pushed back like this it makes the helmet look a
little bit as if it has a cap-like peak in front, but not really, and anyways on the Greek coins they always seem to depict the eye cut-outs so it's obvious what you are looking at.
On coins of Constantine such as yours, these peaked helmets are typically shown with the protruding peak joining a more bowl-like top at an angle, and I've never seen one with eye cut-outs depicted that would make it obvious it's meant to be a somewhat stylized Corinthian helmet.
Any opinion? Corinthian or not? I've not been able to find any other period-correct type of helmet with a peak like this.
