Theory Seminar: Asymptotic Symmetries and Gravitational Waves
Date:
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Location:
CP179
Theory Seminar
Theory Seminar: Searching for Physics Beyond the Standard Model from Lattice QCD
After the discovery of the Higgs boson, physicists keep searching for New Physics in cosmic, energy and intensity frontiers. In the intensity frontier, a key stone is to provide precise Standard Model prediction by controlling the uncertainty from low energy QCD.
Lattice QCD has been developed to tackle the nonperturbative problems in low energy QCD. It has been demonstrated to be a powerful tool in dealing with the ''gold-plated'' observables such as the hadron spectra and decay constants. To meet the requirement of future experiments in the intensity frontier, we need to study more complicated system beyond gold-plated.
Rare kaon decay is such an example. The cleanliness of the Standard Model predication of the branching ratio for the rare kaon decays K^+ -> pi^+ nu nu-bar and K_L -> pi^0 nu nu-bar make them an ideal place to search for New Physics. The CERN NA62 experiment aims for an observation of O(100) events of K^+ -> pi^+ nu nu-bar decay and a 10%-precision measurement of the branching ratio. The KOTO experiment at J-PARC in Japan aims for first observation of the CP-violating decay K_L -> pi^0 nu nu-bar.
In this talk I will present an exploratory study of the long-distance contributions to the K+ -> pi+ nu nu-bar decay amplitude from first principles using lattice QCD. Such study is necessary to interpret future experiments at a 10% precision or better.
Date:
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Location:
CP179
Theory Seminar: The confinement/deconfinement transition in holographic QCD
Date:
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Location:
CP179
Theory Seminar: Geometric constraints on the space of N=2 conformal field theories
Seiberg-Witten theory provides a geometric understanding of N=2 gauge theories while Conformal invariance further constrains the Coulomb branch to be scale-invariant. We will show that this picture is richer: Coulomb branch deformations are related in a precise way to the spectrum of relevant, irrelevant and marginal operators of the SCFT. In particular, a careful study of the former can constraint the latter, geometric constraints on the space of possible N=2 SCFTs can be extracted and a classification scheme can be outlined. In particular, we carry out this program for the rank 1 case.
Some of the constraints on the space of SCFTs which can be obtained in a straightforward way with our approach are instead harder to extract using bootstrap techniques. These two approaches should be thus seen as complementary to one another.
Date:
-
Location:
CP179
