INDIANAPOLIS - US Republican presidential candidate Ted Cruz, in a last-ditch bid to slow front-runner Donald Trump's momentum, on Wednesday named former business executive Carly Fiorina to be his vice presidential running mate if he wins the nomination.After suffering a series of crushing losses to Trump in nominating contests on Tuesday, Cruz praised Fiorina as a principled fighter for conservative values who knew how to create jobs and would be a valuable ally on the campaign trail."She is careful. She is measured. She is serious," Cruz said. "She doesn't get rattled."Fiorina, 61, dropped her own White House bid in February after a lackluster seventh-place finish in New Hampshire's first-in-the-nation primary. She endorsed Cruz, a 45-year-old US senator from Texas, a month later and has been a sharp critic on the campaign trail of likely Democratic nominee Hillary Clinton.