1. Don't assume people speak your native language (I certainly don't) in an english language forum. Translate relevant parts to english; please.
2. Your distribution (RedHat derived I guess based on yum/rpm) may not ship SFML at all or may not ship the latest version. You'll have to take that up with your distro people.
3. It's trivial to clone the SFML git repository and build (compile) it yourself.
It's Portuguese, I will translate (I'm Portuguese as well)
[root@localhost snake]yum install sfml
Loaded Plugins: langpacks, refresh-packagekit
Resolving dependencies
--> Executing Transaction check
---> The Package sfml.x86_64 0:2.0.0-1.fc19 will be installed
--> Dependencies resolution finished
Dependencies resolved
================================================================================
Package Architecture. Version Repo Size
================================================================================
Installing:
sfml x86_64 2.0.0-1.fc19 sfml 202 k
Short-Version of the transaction
================================================================================
Install 1 Package
Total Size: 202 k
Size after installed: 548 k
Is this ok [y/d/N]: y
Downloading packages:
The Package sfml-2.0.0-1.fc19.x86_64.rpm is not signed
[root@localhost snake]#
btw I translated DIRECTLY to Portuguese, maybe somethings are different because this isn't normal talking... it's Computer stuff.