Abstract: The existence of physics beyond the Standard Model (BSM) is well motivated from both experimental and theoretical points of view. However, data from the 7/8 /13 TeV LHC (Run I and early Run II) have ruled out new, electroweak-scale states that couple appreciably to the Standard Model. This suggests that new physics, if it is indeed accessible at the … Read More
Abstract: We present a mechanism to solve the strong CP problem by embedding QCD in a SU(3)^N product gauge group at high energies. The simplest version of this mechanism realizes a heavy QCD axion by embedding QCD in the diagonal subgroup of a SU(3)xSU(3) gauge group at a scale M~10^14 GeV. The vacuum is naturally aligned to ensure θ=0 at … Read More
“The Higgs potential appears to be fine-tuned, hence very sensitive to values of other scalar fields that couple to the Higgs. We show that this feature can lead to a new epoch in the early universe featuring violent dynamics coupling the Higgs to a scalar modulus. The oscillating modulus drives tachyonic Higgs particle production. We find a simple parametric understanding … Read More
Abstract: Under the assumption that physics beyond the standard model consists of heavy particles well above the electroweak scale, its effects at lower energies can be described by an effective field theory, either SMEFT or HEFT above the electroweak scale. Below the electroweak scale, either theory should be mapped to a low-energy EFT (LEFT), where the heavy standard-model particles are … Read More
The QCD axion remains one of the best-motivated proposals for the nature of dark matter. On the largest scales, axion dark matter is extremely cold and effectively pressureless, making it very similar to the WIMP and other candidates. However, as an extremely light scalar particle, axions can attain large occupation numbers, forming overdensities known as miniclusters, which can further collapse … Read More