Narrative:

My radar assist received a call from an adjacent center sector with a question about a crossing restriction and then a point out for aircraft Y to cross dodje at 4;000 feet. We did not have any traffic. I noticed a limited data block in TRACON airspace at 9;000 feet opposite direction from aircraft Y. About 3-4 minutes out; I pulled the 9;000 foot data tag and watched it for a minute assuming TRACON would reference the traffic. After not noticing a temporary 10;000 feet assigned to aircraft Y; I checked to see if TRACON had a data block. They did not; so I sent them a plan view display (pvd) and made a call to see if they knew about the traffic. They did not and then took action to make sure there was separation.I called back a minute later to let him know the crossing restriction would be different. In the process I interrupted a call between the TRACON controller and the center low sector controller. The response from the TRACON controller was ridiculous; saying there was no factor between the two and it was safe to descend. Luckily the other sector controller did not descend aircraft Y and they passed separated vertically; but roughly 1.7 miles laterally while crossing opposite direction.with the required filters for center low sector generally set to 10;800-23;200 feet; they would have never seen the target to know there was traffic. I'm not sure TRACON knew or understood that there are limitations to what we see inside their airspace; although I'm not sure it would have made much of a difference based on the initial response.

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Original NASA ASRS Text

Title: Center Controllers reported receiving approval from TRACON to descend an aircraft into their airspace even though the TRACON had conflicting traffic.

Narrative: My Radar Assist received a call from an adjacent Center sector with a question about a crossing restriction and then a point out for aircraft Y to cross DODJE at 4;000 feet. We did not have any traffic. I noticed a limited data block in TRACON airspace at 9;000 feet opposite direction from aircraft Y. About 3-4 minutes out; I pulled the 9;000 foot data tag and watched it for a minute assuming TRACON would reference the traffic. After not noticing a temporary 10;000 feet assigned to aircraft Y; I checked to see if TRACON had a data block. They did not; so I sent them a Plan View Display (PVD) and made a call to see if they knew about the traffic. They did not and then took action to make sure there was separation.I called back a minute later to let him know the crossing restriction would be different. In the process I interrupted a call between the TRACON controller and the Center Low sector controller. The response from the TRACON controller was ridiculous; saying there was no factor between the two and it was safe to descend. Luckily the other sector controller did not descend aircraft Y and they passed separated vertically; but roughly 1.7 miles laterally while crossing opposite direction.With the required filters for Center Low sector generally set to 10;800-23;200 feet; they would have never seen the target to know there was traffic. I'm not sure TRACON knew or understood that there are limitations to what we see inside their airspace; although I'm not sure it would have made much of a difference based on the initial response.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.