ZOB Supervisor described an airspace incursion event with an adjacent ZNY sector when the hand off status of a transferring aircraft was unclear; the reporter questioning the ZNY's Controller unresponsiveness.

Narrative

Air carrier X was descending in our airspace to meet an LOA restriction of FL250. A hand-off was initiated to ZNY Sector N73. Both the RADAR Controller and myself thought the aircraft hand-off had been flashing at ZNY Center and accepted. Our sector was moderately busy at this time and there were several data blocks flashing conflict alert; including Air carrier X The aircraft was changed to ZNY frequency. A minute later the RADAR Controller said something like;'hey doesn't PSP Sector have the hand-off on that guy?' We both looked closer and realized the data block was in PSB airspace; still flashing at N73 (PSB). The RADAR Controller called PSB Sector and asked them if they had the hand-off. They were somewhat evasive saying; yeah.... They saw him but were waiting to take the hand-off to see if the aircraft was going to make the LOA altitude restriction. As it was the aircraft was not given an altitude crossing restriction by us but instead given an expeditious descent to miss other traffic. The aircraft crossed the ZNY boundary out of about FL260 descending to 250. Why ZNY did not 'at least' take the hand-off after the aircraft reached FL250 is unknown. After this call ZNY took the hand-off. The conflict alert flashing and then stopping seemed to lull us into thinking the hand-off had been accepted by ZNY. It would have been more helpful if ZNY called us and asked us about aircraft's altitude if there was a question; rather than ignoring the hand-off all together.