No, the design requirements of a rich text field is to include only html mark up and strip away active content such as javascript. All JS event handlers are removed and only a whitelisted set of tags and attributes are allowed. Remember that rich text field text output should be rendered with an escape="false"
flag to avoid double rendering. If JS could be included, that would be a stored XSS vulnerability. This is because Author Apex (a profile-level permission) is required to add code to a Salesforce organization, whereas different permissions control access to sObject fields.
In general, the platform does not support the storing and subsequent execution of Javascript code in any sObject field, including rich text fields and URL types (you cannot include a javascript:
pseudo-scheme in URL fields, either). If you want to store and run JS code and you have author apex, then put your code in a Visualforce page, Lightning component controller or renderer, or in static resources loaded by your VF page or lightning component. You can also put Javascript into custom button handlers that you create. But you wont be able to execute code just by updating the contents of sObjects.
You could intentionally write a vulnerable visualforce page that has a mergefield that is not properly escaped. For example:
<script>
{!my_field}
</script>
But hopefully whoever is in charge of security for your organization would flag this as a cross site scripting vulnerability. Please don't do this, and maintain the separation of code and data in your own code in order to keep your Salesforce organization secure.