bug when using the integrated search-function

hello. i got this issue, its not a big deal, however i feel like its giving me a certain itch knowing there is a slight “bug” in the piano black theme.. atleast i feel there is one.

ive enabled the search-function within the theme. when i search for something, the pagetitle looks like this (lets say i search for “stones”:

“Search Results stonesstones / BRUS.LI”.

this is what my site-title will be after ive performed a search.
im pretty green at php/css etc, so i would really appreciate any advice about altering the code abit, so the search results wont display twice. (like stonesstones).. i dont know why this happens. i would also like to change “Search Results” to something else.
i do know the code probably is in header.php, but could anyone point me in the right direction here? 🙂