Stefania Gori (Perimeter Institute) “A flavorful Higgs “
Measurements of Higgs production and decays have revealed that most of the electroweak symmetry breaking is due to the 125 GeV Higgs field. Similarly, we know that the Higgs is at least partially responsible for giving mass to the top and bottom quarks, and tau lepton. Much less is known about the origin of mass for the first two generations, … Read More
Maurizio Pierini (CERN): Signs of Hope
Abstract During the first LHC long shutdown, the CMS and ATLAS collaborations finalized the study of the 8TeV data collected in 2012. Within the impressive amount of results produced, a few searches for new physics show a “coherent” small tension with the prediction from the Standard Model. While the significance is still too small to allow any conclusion, some of … Read More
Particle Theory Seminar | Da Liu (UC Davis) “Gauge Invariance from On-Shell Massive Amplitudes and Tree-level Unitarity”
Abstract: In this talk, I will discuss about my recent work about the on-shell understanding of the spontaneously broken gauge theories by employing the on-shell massive spinor formalism and tree unitarity. We start from the most general on-shell three-particle amplitudes with energy growing behavior at most of O(E) involving arbitrary, finite number of massive scalars, spinors and vectors. Then the … Read More
Particle Theory Seminar | Jessica Howard (KITP & UCSB) “Dark Matter Freeze-out during SU(2)_L Confinement”
In this talk, we will explore the possibility that dark matter is a pair of SU(2)_L doublets and consider a novel mechanism of dark matter production that proceeds through the confinement of the weak sector of the Standard Model. This phase of confinement causes the Standard Model doublets and dark matter to confine into pion-like objects. Before the weak sector … Read More
No Seminar
Particle Theory Seminar | David Cyncynates (Washington U.) “Detectable Dark Photon Dark Matter”
Abstract: Dark photons are excellent dark matter candidates and offer compelling experimental targets. However, recently it has been shown that the simplest production scenarios (e.g. inflationary production and axion-dark photon conversion) lead to the formation of topological defects rather than nonrelativistic dark matter, substantially restricting the viable parameter space. I will first explain how defect formation constrains dark photon production … Read More
Particle Theory Seminar | Pablo Quilez (UCSD) ” Automatic Nelson-Barr from Gauged Flavor and ALP searches at FASER”
Despite the exceptional appeal of the Peccei-Quinn mechanism as a solution to the strong CP problem, alternative mechanisms should still be pursued. In this direction, I will present in the first part of my talk how a Nelson-Barr mechanism (NB) arises automatically in the context of gauged flavor models. Given the tight connection of the strong CP problem with flavor, … Read More
Particle Theory Seminar | Seth Koren (U. of Chicago) “Putting Generalized Symmetries to Work for Particle Physics”
Abstract: Over the past decade, field theorists have developed a novel framework for thinking about global symmetries which has enormously generalized our understanding thereof. Quite recently, my collaborators and I have established positively that past being a useful formal tool, such generalized symmetries are indeed present in models that we care about as particle physicists—and furthermore understanding them can lead … Read More
Particle Theory Seminar | Lingfeng Li (Brown U.) “New inflationary probes of axion dark matter””
“If a light axion is present during inflation and becomes part of dark matter afterwards, its quantum fluctuations contribute to dark matter isocurvature. In this article, we introduce a whole new suite of cosmological observables for axion isocurvature, which could help test the presence of axions, as well as its coupling to the inflaton and other heavy spectator fields during … Read More
Particle Theory Seminar | Liantao Wang (U. of Chicago) “Gravitational wave signals of early universe dynamics”
Abstract: Gravitational wave signals can reveal new information about the dynamics of the early universe and are complementary to other probes. I will use several examples to illustrate what kind of signal we should expect and what we can learn from them.