A new poll found Massachusetts Sen. Scott Brown (R) and presumptive Democratic nominee Harvard Law School professor Elizabeth Warren essentially tied in the tossup Senate race.

Warren led Brown by 3 points in a horse-race matchup, 46 percent to 43 percent — within the margin of error. Eleven percent of those polled didn’t know for whom they would vote.

Both candidates are well-known in the state. Fifty percent of those polled had a favorable view of Brown while 29 percent had an unfavorable impression of him; 15 percent had heard of him but were undecided. Thirty-nine percent of those polled had a favorable view of Warren, while 29 percent had an unfavorable impression of her; 15 percent had heard of her but were undecided.

Warren, who grew up in Oklahoma, is seen by only 13 percent of those surveyed as having “deep roots here in Massachusetts.” Brown gets 39 percent on that question.

But 34 percent thought Warren “seems to be gaining momentum lately for the November election,” while only 24 percent felt that way about Brown.

The WBUR poll, conducted by MassINC Polling Group, surveyed 503 likely voters by land line and cellphone and had a margin of error of 4.4 points. It was conducted Feb. 6-9.