{"@context":"http://schema.org","@id":"https://doi.org/10.17182/hepdata.127978.v1","@reverse":{"isBasedOn":[{"@type":"ScholarlyArticle","identifier":{"@type":"PropertyValue","propertyID":"URL","value":"https://inspirehep.net/literature/1762362"}},{"@id":"https://doi.org/10.1103/PhysRevLett.125.012301","@type":"JournalArticle"}]},"@type":"Dataset","additionalType":"Collection","author":{"@type":"Organization","name":"ALICE Collaboration"},"creator":{"@type":"Organization","name":"ALICE Collaboration"},"datePublished":"2024","description":"The first evidence of spin alignment of vector mesons ($K^{*0}$ and $\\phi$) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element $\\rho_{00}$ is measured at midrapidity ($|y| <$ 0.5) in Pb-Pb collisions at a center-of-mass energy ($\\sqrt{s_{\\rm NN}}$) of 2.76 TeV with the ALICE detector. $\\rho_{00}$ values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum ($p_{\\rm T} <$ 2 GeV/$c$) for $K^{*0}$ and $\\phi$ at a level of 3$\\sigma$ and 2$\\sigma$, respectively. No significant spin alignment is observed for the $K^0_S$ meson (spin = 0) in Pb-Pb collisions and for the vector mesons in $pp$ collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.","hasPart":[{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t1","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\rm{K}^{*0}$ (average of particle and anti-particle) meson w.r.t. Event Plane in transverse momentum range 0.8-1.2 GeV/$c$ measured...","name":"Table 1"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t2","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\phi$ meson w.r.t. Event Plane in transverse momentum range 0.5-0.7 GeV/$c$ measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$...","name":"Table 2"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t3","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\rm{K}^{*0}$ (average of particle and anti-particle) meson w.r.t. Production Plane in transverse momentum range 0.4-1.2 GeV/$c$ measured...","name":"Table 3"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t4","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\phi$ meson w.r.t. Production Plane in transverse momentum range 0.5-0.8 GeV/$c$ measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$...","name":"Table 4"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t5","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\rm{K}^{*0}$ (average of particle and anti-particle) meson w.r.t. Random Plane in transverse momentum range 0.8-1.2 GeV/$c$ measured...","name":"Table 5"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t6","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\phi$ meson w.r.t. Random Plane in transverse momentum range 0.5-0.7 GeV/$c$ measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$...","name":"Table 6"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t7","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of K$^{0}_{S}$ meson w.r.t. Event Plane in transverse momentum range 0.6-0.8 GeV/$c$ measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$...","name":"Table 7"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t8","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of K$^{0}_{S}$ meson w.r.t. Production Plane in transverse momentum range 0.6-0.8 GeV/$c$ measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$...","name":"Table 8"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t9","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\rm{K}^{*0}$ (average of particle and anti-particle) meson w.r.t. Production Plane in transverse momentum range 0-0.6 GeV/$c$ measured...","name":"Table 9"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t10","@type":"Dataset","description":"$cos\\theta^{*}$ distribution of $\\phi$ meson w.r.t. Production Plane in transverse momentum range 0.5-0.8 GeV/$c$ measured in pp collisions at $\\sqrt{s}$...","name":"Table 10"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t11","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Event Plane for $\\rm{K}^{*0}$ (average of particle and anti-particle) meson measured in...","name":"Table 11"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t12","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Event Plane for $\\rm{K}^{0}_{S}$ meson measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$ =...","name":"Table 12"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t13","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Event Plane for $\\phi$ meson measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$ =...","name":"Table 13"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t14","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Production Plane for $\\rm{K}^{*0}$ (average of particle and anti-particle) meson measured in...","name":"Table 14"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t15","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Production Plane for $\\rm{K}^{*0}$ (average of particle and anti-particle) meson measured in...","name":"Table 15"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t16","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Production Plane for $\\rm{K}^{0}_{S}$ meson measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$ =...","name":"Table 16"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t17","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Production Plane for $\\phi$ meson measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$ =...","name":"Table 17"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t18","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Production Plane for $\\phi$ meson measured in pp collisions at $\\sqrt{s}$ =...","name":"Table 18"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t19","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Random Plane for $\\rm{K}^{*0}$ (average of particle and anti-particle) meson measured in...","name":"Table 19"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t20","@type":"Dataset","description":"$\\rho_{00}$ as a function of $p_{\\rm T}$ w.r.t. Random Plane for $\\phi$ meson measured in Pb-Pb collisions at $\\sqrt{s_{NN}}$ =...","name":"Table 20"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t21","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Production Plane in transverse momentum range 0.4-1.2 GeV/$c$ for $\\rm{K}^{*0}$ (average...","name":"Table 21"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t22","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Production Plane in transverse momentum range 3.0-5.0 GeV/$c$ for $\\rm{K}^{*0}$ (average...","name":"Table 22"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t23","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Production Plane in transverse momentum range 0.5-0.8 GeV/$c$ for $\\phi$ meson...","name":"Table 23"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t24","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Production Plane in transverse momentum range 3.0-5.0 GeV/$c$ for $\\phi$ meson...","name":"Table 24"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t25","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Event Plane in transverse momentum range 0.8-1.2 GeV/$c$ for $\\rm{K}^{*0}$ (average...","name":"Table 25"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t26","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Event Plane in transverse momentum range 3.0-5.0 GeV/$c$ for $\\rm{K}^{*0}$ (average...","name":"Table 26"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t27","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Event Plane in transverse momentum range 0.5-0.7 GeV/$c$ for $\\phi$ meson...","name":"Table 27"},{"@id":"https://doi.org/10.17182/hepdata.127978.v1/t28","@type":"Dataset","description":"$\\rho_{00}$ as a function of $\\langle N_{\\rm{part}} \\rangle$ w.r.t. Event Plane in transverse momentum range 3.0-5.0 GeV/$c$ for $\\phi$ meson...","name":"Table 28"}],"identifier":[{"@type":"PropertyValue","propertyID":"HEPDataRecord","value":"https://www.hepdata.net/record/ins1762362?version=1"},{"@type":"PropertyValue","propertyID":"HEPDataRecordAlt","value":"https://www.hepdata.net/record/127978"}],"inLanguage":"en","name":"Measurement of spin-orbital angular momentum interactions in relativistic heavy-ion collisions","provider":{"@type":"Organization","name":"HEPData"},"publisher":{"@type":"Organization","name":"HEPData"},"url":"https://www.hepdata.net/record/ins1762362?version=1","version":1}