By Susan Mathew and Ankika Biswas (Reuters) – U.S. stock indexes slipped on Thursday as worries of a global economic downturn from aggressive central bank rate hikes and risks of potential contagion from a turmoil in UK markets turned investors risk averse. Out of the 11 S&P sector indexes, six of them dropped more than 2%. The Nasdaq fell over 1% due to losses in megacap growth names such as Amazon.com Inc, Apple Inc, Microsoft Corp, Meta Platforms Inc and Tesla Inc. They were down between 2.41% and 4.12%. The calm brought about by the Bank of England’s decision on Wednesday to buy long-dated…