Valuable information on dynamics of expanding fluids can be inferred from the response of such systems to perturbations in their initial geometry.We apply this technique in high-energy^(96)Ru+^(96)Ru and^(96)Zr+^(96)Z...Valuable information on dynamics of expanding fluids can be inferred from the response of such systems to perturbations in their initial geometry.We apply this technique in high-energy^(96)Ru+^(96)Ru and^(96)Zr+^(96)Zr collisions to scrutinize the expansion dynamics of the quark-gluon plasma,where the initial geometry perturbations are sourced by the differences in deformations and radial profiles between^(96)Ru and^(96)Zr,and the collective response is captured by the change in anisotropic flow Vn between the two collision systems.Using a transport model,we analyze how the nonlinear coupling between lower-order flow harmonics V_(2)and V_(3)to the higher-order flow harmonics V_(4)and V_(5),expected to scale as V_(4)NL= χ_(4)V_(2)2and V_(5)NL= χ_(5)V_(2)V_(3),gets modified as one moves from^(96)Ru+^(96)Ru to^(96)Zr+^(96)Zr systems.We find that these scaling relations are valid to high precision:variations of order 20% in V_(4)NLand V_(5)NLdue to differences in quadrupole deformation,octupole deformation,and nuclear skin modify χ_(4)and χ_(5)by about 1–2%.Percent-level deviations are however larger than the expected experimental uncertainties and could be measured.Therefore,collisions of isobars with different nuclear structures are a unique tool to isolate subtle nonlinear effects in the expansion of the quark-gluon plasma that would be otherwise impossible to access in a single collision system.展开更多
高能核-核碰撞致力于实验室制造和研究夸克-胶子等离子体(quark-gluon plasma, QGP),并探索强相互作用物质的相变和相图.自相对论重离子对撞机(Relativistic Heavy Ion Collider, RHIC)和大型强子对撞机(Large Hadron Collider, LHC)的...高能核-核碰撞致力于实验室制造和研究夸克-胶子等离子体(quark-gluon plasma, QGP),并探索强相互作用物质的相变和相图.自相对论重离子对撞机(Relativistic Heavy Ion Collider, RHIC)和大型强子对撞机(Large Hadron Collider, LHC)的重离子碰撞实验运行以来,各种实验证据表明夸克-胶子等离子体已经产生.相对论流体力学及耦合模型关于集体流的计算表明夸克-胶子等离子体是近乎完美的流体.展开更多
基金supported by DOE DE-FG02-87ER40331funded by the Deutsche Forschungsgemeinschaft (DFG,German Research Foundation) under Germanys Excellence Strategy EXC2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster),within the Collaborative Research Center SFB1225 (ISOQUANT,Project-ID 273811115)。
文摘Valuable information on dynamics of expanding fluids can be inferred from the response of such systems to perturbations in their initial geometry.We apply this technique in high-energy^(96)Ru+^(96)Ru and^(96)Zr+^(96)Zr collisions to scrutinize the expansion dynamics of the quark-gluon plasma,where the initial geometry perturbations are sourced by the differences in deformations and radial profiles between^(96)Ru and^(96)Zr,and the collective response is captured by the change in anisotropic flow Vn between the two collision systems.Using a transport model,we analyze how the nonlinear coupling between lower-order flow harmonics V_(2)and V_(3)to the higher-order flow harmonics V_(4)and V_(5),expected to scale as V_(4)NL= χ_(4)V_(2)2and V_(5)NL= χ_(5)V_(2)V_(3),gets modified as one moves from^(96)Ru+^(96)Ru to^(96)Zr+^(96)Zr systems.We find that these scaling relations are valid to high precision:variations of order 20% in V_(4)NLand V_(5)NLdue to differences in quadrupole deformation,octupole deformation,and nuclear skin modify χ_(4)and χ_(5)by about 1–2%.Percent-level deviations are however larger than the expected experimental uncertainties and could be measured.Therefore,collisions of isobars with different nuclear structures are a unique tool to isolate subtle nonlinear effects in the expansion of the quark-gluon plasma that would be otherwise impossible to access in a single collision system.
文摘高能核-核碰撞致力于实验室制造和研究夸克-胶子等离子体(quark-gluon plasma, QGP),并探索强相互作用物质的相变和相图.自相对论重离子对撞机(Relativistic Heavy Ion Collider, RHIC)和大型强子对撞机(Large Hadron Collider, LHC)的重离子碰撞实验运行以来,各种实验证据表明夸克-胶子等离子体已经产生.相对论流体力学及耦合模型关于集体流的计算表明夸克-胶子等离子体是近乎完美的流体.
