Lattice Evidence that Scalar Glueballs Are Small

Here, this Letter reports the first calculation of the gravitational form factors (GFFs) of the scalar glueball, performed via lattice field theory in Yang-Mills theory at a single lattice spacing. The glueball GFFs are compared with those of other hadrons as determined in previous lattice calculations, providing strong indications that glueballs have a different gluonic structure than typical hadronic states. A mass radius of 0.263(31) fm is predicted, supporting previous suggestions that the scalar glueball is significantly smaller than other hadrons.. Authors: Abbott, Ryan [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)] (ORCID:0000000258778005); Hackett, Daniel C. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)] (ORCID:0000000160393801); Pefkou, Dimitra A. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000247190417); Romero-López, Fernando [University of Bern (Switzerland)]; Shanahan, Phiala E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)] (ORCID:0000000209167603). DOE Contract: 89243024CSC000002; AC02-05CH11231; FG02-00ER41132; SC0004658; SC0011090; SC0021006; SC0023116; SC0023646; SC0024053