Mario Tama/Getty ImagesMcDonald's has started trials of its new bigger burger — the Big Arch.By using a brand name rather than a descriptor, companies can "signal superiority," a marketing professor said.The Golden Arches are synonymous with McDonald's, just like Grimace and the Hamburglar.The prefix "Mc" has become synonymous with the world's biggest burger chain.It's not just in the name of the company.