I created a new page on my website and I want to define this page name in Omniture to track more easyly.
Could somebody help me on my issue?
You can pass s.pageName variable in your source code along with other Analytics variable. With that, the page name passed in that variable will appear in Pages report.
For example, s.pageName = "My Page"
See this: pageName
Another method would be to use Name Pages: Name Pages in Analytics UI, though it isn't recommended as it can cause issues in future.
Hope this helps!