In respect to this, when you delete a tweet is it gone?
When you delete a Tweet, it is removed from your account, the timeline of any accounts that follow you, and from Twitter search results on twitter.com, Twitter for iOS, and Twitter for Android. Retweets of the deleted Tweet will also be removed on twitter.com, Twitter for iOS, and Twitter for Android.
One may also ask, how long does it take Twitter to delete a tweet? Usually it will take couple of minutes but sometimes it may take up to two hours.
Keeping this in consideration, how long does it take a deleted tweet to disappear?
14 days
How do I know if someone deleted my tweet?
Twitter itself keeps an archive of all the tweets, even the deleted ones. But for security and privacy of the users, you can never find a tweet someone has deleted. But the original account which has tweeted it can have access to it. They can easily request for their archive and see the deleted tweets.