In grand unified theories (GUTs), such as those attempting to unify the strong, weak, and electromagnetic forces, additional particles beyond those in the Standard Model are postulated. These particles, such as X and Y bosons, are predicted to exist in some GUT models.
If these hypothetical GUT particles exist, their masses could indeed be acquired through interactions with the Higgs boson. The Higgs boson is responsible for the mechanism of electroweak symmetry breaking in the Standard Model, which gives mass to the W and Z bosons as well as to fermions (quarks and leptons). In some GUT models, the Higgs field responsible for electroweak symmetry breaking may also participate in the symmetry breaking of the GUT force. This could give rise to the masses of the X and Y bosons.
However, it's important to note that the specific details and predictions of GUT models can vary significantly, and there is no consensus on which GUT model, if any, accurately describes our universe. The energies required to directly produce and detect GUT particles are currently beyond the reach of our particle accelerators. Therefore, we have not observed direct evidence of the coupling between the Higgs boson and the hypothetical GUT particles.
To search for indirect evidence or constraints on GUT models, scientists rely on various indirect methods, such as precision measurements of particle interactions, astrophysical observations, and theoretical considerations. These investigations help to place constraints on the possible masses and couplings of GUT particles and guide future experimental efforts. It remains an active area of research to explore the predictions and implications of GUT models and to search for experimental evidence supporting or ruling out these theories.