Upcoming Seminars

Date/Place Dec. 18th (Tue.) 15:30-16:30 / H711
Name Arindam Das (Osaka U.)
Title Right handed neutrinos: a roadmap from the energy to the intensity frontiers
Abstract In this talk we will study the mass generation mechanisms of the Standard Model (SM) light neutrinos through the commonly known seesaw and inverse seesaw mechanisms which involve SM gauge singlet heavy Majorana right handed neutrinos. We fix the model parameters to reproduce the neutrino oscillation data and to satisfy other experimental constraints, assuming the typical flavor structure/s of these models and the different types of hierarchical light neutrino mass spectra. With the fixed parameters in this way, we analyze the heavy neutrino signal at the colliders. For completeness, we also consider a general parameterization for the model parameters by introducing an arbitrary orthogonal matrix, and the non-zero Dirac and Majorana phases. We perform parameter scan to identify an allowed parameter region which satisfies all experimental constraints. We find that in some cases, the heavy neutrino signal can be observed with a large statistical significance via different flavour charged lepton final states. We will also discuss about the significance of these right handed neutrinos in the intensity frontier beyond the collider searches.

 

Date/Place Jan. 8th (Tue.) 15:30-16:30 / H711
Name Akihiro Ishibashi (Kinki U.)
Title The Quantum Null Energy Condition and its violation
Abstract In this talk I will discuss the quantum null energy condition (QNEC) in curved spacetime. First, I will give a brief review on the (achronal) averaged null energy condition, its major role in spacetime physics, the quantum focusing conjecture, and the notion of QNEC. Then, I will examine the QNEC for a CFT in a wormhole spacetime by using AdS-CFT correspondence. Our bulk spacetime is a numerically constructed AdS black hole solution to the 3+1-dimensional vacuum Einstein equations with a 2+1-dimensional wormhole on its conformal boundary. By computing the IR-regularized entanglement entropy for a half-space anchored to the wormhole throat, it is shown that the QNEC can be violated around the throat. This indicates that IR-effects are crucial for QNEC. This talk is based on the joint work arXiv:1808.05192 with Kengo Maeda and Eric Mefford.

 

Date/Place Jan. 15th (Tue.) 15:30-16:30 / H711
Name Katsura Hosho (U. of Tokyo)
Title TBA
Abstract TBA

 

Date/Place Jan. 22nd (Tue.) 15:30-16:30 / H711
Name Shinji Takeda (Kanazawa U.)
Title QCD phase diagram
Abstract It is known that the nature of finite temperature QCD phase transition depends on the number of quark flavors and quark masses. Such a situation is often pictorially summarized as the Columbia plot. There is an important and longstanding issue on the structure of the plot, namely the location of the critical line which separates the first order phase transition region from the cross-over region. In this talk, I will review and show some recent progresses on the issue by lattice QCD simulations. I will also address another issue how the Columbia plot is affected by the presence of finite quark density.

 

Date/Place Jan. 29th (Tue.) 15:30-16:30 / H711
Name Takahiro Sagawa (U. of Tokyo)
Title TBA
Abstract TBA

 

Date/Place Apr. 9th (Tue.) 15:30-16:30 / H711
Name Yu Nakayama (Rikkyo U.)
Title TBA
Abstract TBA

 

Past Seminars