Like Linux versus Windows, different research shows different results. There are so many variables here. This question is like asking: Which production car can go fastest on the race track? There are variables such as the track, the weather, the driver, the tires, and so on. There's no one best answer.
In security testing, I generally find C/C#-based applications to be more secure than Java, but there's an infinite number of variables like the developer's coding skills, the functions of the application, the attack surface, and so on.
The most secure language is the one that's coded most securely. Again, this is pretty hard to quantify.