Launcher remains running on memory

When using the newest launcher (1.3.7) regardless profile, mod, settings, after pressing "play" the launcher's window closes, but does not stops from running, i discover the 'extra' javaw.exe' on my task manager that was causing me some lag in my modded version, i ended process, the lag stopped and didn't end my MC game, i have repeated this many times with different versions of the game, mods, etc and the launcher keeps running on memory