How to call variabled ajax

Question

I put the ajax call in a variable, how can I call it again and pass some parameters to the data attribute of the ajax?.

var request = $.ajax({
    URL: '/usage_analytics.php',
    type: 'get',
    data: {date_start: dt_date_start, date_end: dt_date_end},
    dataType: 'json'
});

request.done(function (r) {
    console.log(r);
    //my codes goes here
});

now I have a date range picker, If i click apply button i just want to call the request variable to be able to trigger the ajax call again and pass some parameters.

$('#reportrange').on('apply.daterangepicker', function(ev, picker) {
    var picked_start = picker.startDate.format('YYYY-MM-DD');
    var picked_end   = picker.endDate.format('YYYY-MM-DD');

    dt_date_start = picked_start;
    dt_date_end   = picked_end;
    //call the request here and pass the dt_date_start and dt_date_end
});

TIA