If you are signed in, you can save searches permanently. To do so, click ‘Save query’ above the results list:

Note: The “Save query” option is only displayed after you sign in and run a search.

When saving a query, you can choose to receive email notifications about updates. To activate this service, a message will automatically appear at the top of the page.

Notification banner stating ‘The search query was saved to your favorites’ with a link to turn on notifications for the query, and a "Dismiss" button.
Notification settings: To save a query, enter your e-mail, then select the button "save query"

Saved searches are stored in "My Favorites" under the "Saved searches" tab.

Click a search to run it again. Use the icons on the right to set up notifications (via RSS or email) and stay informed about newly added documents that match your search.