England’s Chris Ashton was banned for four weeks from all rugby on Tuesday for pulling the hair of Leicester’s Alesana Tuilagi during Northampton’s Premiership defeat by the Tigers on Saturday. Ashton, who was punished by a disciplinary panel for “acts contrary to good sportsmanship,” will be free to play again on Jan.4 — a month before England begin the defence of their Six Nations title. The incident took place in the first half of a fiery East Midlands derby won 30-25 by Leicester at their Welford Road home and sparked a touchline brawl.Tuilagi and Northampton flanker Tom Wood were sent off but a disciplinary panel found the red cards they had received for striking were sufficient punishment and both can continue to play. Agenc