prevent url string to encode & to &

I am using cakephp ajax pagination for my web application.

In this application i have implemented search filters also. When user filter the records, i submit the search form using GET method, in controller i get the filter variables and append them to the paginator helper like this.

$this->paginator->options(array(
    'url' => array_merge($this->passedArgs, array('?'=> $query_string)), 
    'update' => '#tlist', 
    'evalScripts' => true)
);

My problem is that in my pagination link my all & is get converted into & See below and look at the bold part.

<a href="/sites/tutor/users/ajaxtutor/page:2?gender%5B0%5D=1&gender%5B1%5D=2" id="link-1795722171" />;

And when i click on the link i do get query String as below:

[gender] => Array
        (
            [0] => 1
        )
[amp;gender] => Array
        (
            [1] => 2
        )

how to remove this extra amp; from the query string.

Can anybody help how to cope with this situation.

Solution

As guffa said the conversion is correct from & to & as it is html standard.

The problem was that cakephp picks pagination link's href part which contains & in place of & and put it into ajax url section. See below for example:

Pagination links:
<a href='somedomain.com?&a=1&b=2>1</a>
Generated ajax code:

$("#link-1478709635").bind("click", function (event) {
    $.ajax({
        url: "somedomain.com?&amp;a=1&amp;b=2"
    });
    return false;

And when we click on the link it will take & in place of & with it.
As a solution i used Post method in place of GET method to post my data back with pagination links in paginator options like this: 'data'=>http_build_query($this->request->data),

prevent url string to encode & to &amp;

prevent url string to encode & to &