ng pattern for allowing only '-' in input text box

Is there any pattern that will allow only '-' in the input text box and deny entering other special characters like @, #, $ etc.I tried with the pattern ng-pattern="/^[a-zA-Z0-9]*$/" which will deny all special characters from being entered in the field.

   <form name="myForm">
    <input type="text" ng-pattern="/^[a-zA-Z0-9]*$/" ng-model="name" name="name">
    </form>
  <span class="error pop_up"  ng-show="myForm.name.$error.pattern">Special Characters are not allowed</span>