Naoki Yoshida, Tokyo Univ.
Cosmological constraints on dark matter annihilation and decay
Meeting room 3, Kenkyu honkan 1F
We present the results from cross-correlation analysis of weak gravitational lensing and the extra-galactic gamma-ray radiation. The former provides the large scale distribution of dark matter, and the latter possibly includes high energy photons produced by dark matter self-annihilation or decay. We use data from CFHT, SDSS, RCSLens galaxy surveys and the Fermi all-sky survey. We generate a large set of full-sky mock catalogs from cosmological N-body simulations and use them to estimate statistical errors accurately. The measured cross-correlation is consistent with null detection, which is then used to place strong cosmological constraints on annihilating and decaying DM. For leptophilic DM, the constraints are improved by a factor of 100 in the mass range of ~TeV when including contributions from secondary gamma-rays due to the inverse -Compton upscattering of background photons. Annihilation cross sections of 10^{-23} cm3/s are excluded for TeV-scale DM. Lifetimes of 10^25 sec are also excluded for the decaying TeV-scale DM. These are real cosmological constraints, rather than being obtained from local structures.
Eigo Shintani, RIKEN-AICS
Lattice computation of nucleon matrix element related to BSM physics
Meeting room 1, Kenkyu honkan 1F
I will review the recent nucleon matrix element computation related to BSM physics, e.g. EDM, proton decay, etc, in lattice QCD.
Hiroaki Sugiyama, Toyama Univ.
Exploring neutrino mass generation mechanisms via the lepton flavor violating decay of the Higgs boson
Meeting room 1, Kenkyu honkan 1F There are many new physics models for generating neutrino masses, and it is important to consider how these models can be experimentally discriminated. Classification of models is useful for the efficient discrimination. In this talk, we classify simple models for each of Majorana and Dirac neutrino masses by concentrating on Yukawa interactions with leptons. We see that, if a lepton flavor violating decay of the Higgs boson is discovered, simple models for Majorana neutrino masses are excluded while some models for Dirac neutrino masses can survive.
There are many new physics models for generating neutrino masses, and it is important to consider how these models can be experimentally discriminated. Classification of models is useful for the efficient discrimination. In this talk, we classify simple models for each of Majorana and Dirac neutrino masses by concentrating on Yukawa interactions with leptons. We see that, if a lepton flavor violating decay of the Higgs boson is discovered, simple models for Majorana neutrino masses are excluded while some models for Dirac neutrino masses can survive.
[1] S. Kanemura and H. Sugiyama, Phys. Lett. B753, 161 (2016). [2] S. Kanemura, K. Sakurai and H. Sugiyama, Phys. Lett. B758, 465 (2016). [3] M. Aoki, S. Kanemura, K. Sakurai and H. Sugiyama, Phys. Lett. B763, 352 (2016).
Ignatios Antoniadis, University of Bern
Aspects of string phenomenology and scale hierarchies
Meeting room 3, Kenkyu honkan 1F
I will discuss the problem of scale hierarchies in string phenomenology of particle physics and cosmology and propose ways to address it. In particular I will present a mechanism for supersymmetry breaking in the presence of a tiny (tunable) positive cosmological constant and describe its phenomenological consequences
Ryosuke Sato, Weizmann Inst.
Spherical symmetry of the bounce solution
Meeting room 3, Kenkyu honkan 1F
