This paper explores the constraints on massive particles during inflation using the "Cosmological Collider" approach, which treats the early universe as a natural particle accelerator. The authors use data from the BOSS redshift-space galaxy power spectrum and bispectrum multipoles, along with Planck CMB non-Gaussianity data, to search for spin-zero particles interacting with the inflaton. They demonstrate that some Cosmological Collider models can be approximated by the standard equilateral and orthogonal parametrization, allowing them to translate Planck non-Gaussianity constraints into bounds on collider models. However, many models have signatures not degenerate with equilateral and orthogonal non-Gaussianity and require dedicated searches. The authors use BOSS three-dimensional redshift-space galaxy clustering data to constrain such models, focusing on spin-zero particles in the principal series and their couplings to the inflaton at varying speed and mass. This is made possible through improved Cosmological Bootstrap techniques and the combination of perturbation theory and halo occupation distribution models for galaxy clustering. The work sets the standard for inflationary spectroscopy with cosmological observations, providing the ultimate link between physics on the largest and smallest scales. The paper discusses the observables in the Cosmological Collider, including the inflationary action and correlation functions, and presents results from Planck constraints on spin-zero massive particles, obtained from the published $ f_{NL}^{equil} $ and $ f_{NL}^{ortho} $ bounds, assuming negligible inflaton self-interactions. The results show the mean and 95% CL bound for the first amplitude and the 95% CL upper limit for the second, noting that $ \beta^{(\nabla\pi)^{2}\sigma} \geq 0 $. The paper also discusses the DBI Cosmological Collider, where inflaton interactions and their couplings to $ \sigma $ are constrained by a higher-dimensional boost symmetry. The authors find that the projection efficiency is very high for single shape measurements but suffers from significant information loss for joint analyses of both amplitudes. The results are visualized in Figs. 2 & 3, and the constraints are summarized in Tables I and II.This paper explores the constraints on massive particles during inflation using the "Cosmological Collider" approach, which treats the early universe as a natural particle accelerator. The authors use data from the BOSS redshift-space galaxy power spectrum and bispectrum multipoles, along with Planck CMB non-Gaussianity data, to search for spin-zero particles interacting with the inflaton. They demonstrate that some Cosmological Collider models can be approximated by the standard equilateral and orthogonal parametrization, allowing them to translate Planck non-Gaussianity constraints into bounds on collider models. However, many models have signatures not degenerate with equilateral and orthogonal non-Gaussianity and require dedicated searches. The authors use BOSS three-dimensional redshift-space galaxy clustering data to constrain such models, focusing on spin-zero particles in the principal series and their couplings to the inflaton at varying speed and mass. This is made possible through improved Cosmological Bootstrap techniques and the combination of perturbation theory and halo occupation distribution models for galaxy clustering. The work sets the standard for inflationary spectroscopy with cosmological observations, providing the ultimate link between physics on the largest and smallest scales. The paper discusses the observables in the Cosmological Collider, including the inflationary action and correlation functions, and presents results from Planck constraints on spin-zero massive particles, obtained from the published $ f_{NL}^{equil} $ and $ f_{NL}^{ortho} $ bounds, assuming negligible inflaton self-interactions. The results show the mean and 95% CL bound for the first amplitude and the 95% CL upper limit for the second, noting that $ \beta^{(\nabla\pi)^{2}\sigma} \geq 0 $. The paper also discusses the DBI Cosmological Collider, where inflaton interactions and their couplings to $ \sigma $ are constrained by a higher-dimensional boost symmetry. The authors find that the projection efficiency is very high for single shape measurements but suffers from significant information loss for joint analyses of both amplitudes. The results are visualized in Figs. 2 & 3, and the constraints are summarized in Tables I and II.