Pension if a ex wife having been married to her husband 11 years be entitled to his pension if it wasn't in the divorce decree

Probably not since the the division of a penision must be addressed in the property division in your divorce decree. In addition, if you ex-husband is in "pay" status, that is collecting on his pension, it would be nearly impossible to change the pension's status now. Usually a modification to a property settlment in a Judgment must be done within 1 year at the latest and you would have to show fraud, misrepresentation, coercion, or mutual mistake. From your question, it sounds like none of these things exist. You can certainly have a lawyer review your Judgment to be sure there is no reference to any retirement benefits that could be construed as a pension but it might cost you more than its worth. Sorry the answer isn't what you were hoping for.