On the eighth day of their search for a new head coach, the Jets decided late this afternoon to offer the job to Patriots defensive coordinator Eric Mangini, a person with knowledge of the situation told Newsday. The team is expected to finalize details on a contract that is likely to make Mangini its next coach as early as Tuesday. Barring any contractual hang-ups, Mangini, who would become the youngest head coach in the NFL at 34, is likely to accept the job. "It looks like he will," said the person, who spoke only on the condition of anonymity. "It's about as likely as anything could be." The situation remains fluid and unfinished, the person cautioned, especially since the Jets finished interviewing their final candidate, former Vikings coach Mike Tice, at 4 p.m. this afternoon. "There's still things that would have to happen and details that would have to be worked on," the person said. "But my perception is that by tomorrow morning, the Jets will have a new coach." Their choice is Mangini, the Hartford, Conn., native who has spent 10 of his 11 years as an NFL assistant with Patriots coach Bill Belichick, including the 2005 season as his defensive coordinator. "It appears as if the job will be his and the club was in the process of putting an offer on the table today," the person said.