How do I remove the site name from the page title on a particular page?
Try the Page Title module. Here is a quote about it (from the module's project page):

The word &quot;title&quot; is a bit overloaded. Every piece of content in Drupal has a title, and so does every page. The page title is the one found in the HTML head inside the  tag. It is also used on SERPs (Search Engine Result Pages) and can greatly enhance your websites SEO (Search Engine Optimization).
This module gives you granular control over the page title. You can specify patterns for how the title should be structured and, on content creation pages, specify the page title separately to the content's title.