Search for the tweets regarding an URL that returns only json?


Am very new to Twitter Integration. One of my requirement is to get no.of tweets for an url, previously i was using API V1 and it was working fine but with V1.1 am not able to fetch the values and instead it gives me Authentication error. so in order to get the search result in json format using the search api, what should i need to do ?

I am using kind of following REST call to get the json response, how can i add OAuth to this ?

Kindly help.