No, colliders or experiments studying quarks have not observed any evidence of quarks exhibiting anti-gravity or floating upwards. Quarks are elementary particles that are subject to the fundamental forces of nature, including gravity. The behavior of quarks within particle accelerators and colliders is consistent with the known laws of physics, including gravity.
It is important to note that quarks have never been observed in isolation due to quark confinement, as discussed earlier. Instead, they are always found bound together in combinations that are subject to the strong nuclear force. The behavior of composite particles, such as protons and neutrons, is consistent with the gravitational interaction that we observe in macroscopic objects.
The concept of anti-gravity or objects with negative mass has not been experimentally verified in the context of known particles. Theoretical speculation on negative mass particles often involves exotic hypothetical particles that have not yet been detected or confirmed by experimental evidence.
It's worth mentioning that the study of gravity at the quantum level and its connection to other fundamental forces is an area of ongoing research and a subject of interest in theories such as quantum gravity and string theory. However, there is no experimental evidence or established theory supporting the existence of negative mass particles or quarks exhibiting anti-gravity behavior.