Yuji Hasegawa, Atominsitut, TU-Wien
Weak-values of neutrons in double-slit experiment --- quantum Cheshire-Cat and weak-value as a complex number ---
Seminar room, Kenkyu honkan 3F Our group in Vienna is promoting neutron optical experiments, i.e., neutron interferometery and polarimetry: both experiments manifest the validity of quantum mechanical predictions with high precision. For instance, an experiment is carried out recently, which deals with error-disturbance uncertainty relation: we have experimentally tested error-disturbance uncertainty relations. Experimental results confirm the fact that the Heisenberg’s uncertainty relation is often violated and that the new relation derived by Ozawa is always larger than the limit. In addition, as an example of a counterfactual phenomenon of quantum mechanics, observation of so-called quantum Cheshire Cat is performed experimentally by using neutron interferometer. Experimental results suggest that pre- and post-selected neutrons travel through one of the arms of the interferometer while their magnetic moment is located in the other arm. In addition, we carried out an experiment to determine weak-value of 1/2-spin as a complex number: experimental results agree well with theoretical prediction. In my talk, I am going to give an overview of activities of weak-value/measurement. Then, I am going to explain neutron ineterferometric experiments concerning two aspects of weak-value/measurement.
Our group in Vienna is promoting neutron optical experiments, i.e., neutron interferometery and polarimetry: both experiments manifest the validity of quantum mechanical predictions with high precision. For instance, an experiment is carried out recently, which deals with error-disturbance uncertainty relation: we have experimentally tested error-disturbance uncertainty relations. Experimental results confirm the fact that the Heisenberg’s uncertainty relation is often violated and that the new relation derived by Ozawa is always larger than the limit. In addition, as an example of a counterfactual phenomenon of quantum mechanics, observation of so-called quantum Cheshire Cat is performed experimentally by using neutron interferometer. Experimental results suggest that pre- and post-selected neutrons travel through one of the arms of the interferometer while their magnetic moment is located in the other arm. In addition, we carried out an experiment to determine weak-value of 1/2-spin as a complex number: experimental results agree well with theoretical prediction. In my talk, I am going to give an overview of activities of weak-value/measurement. Then, I am going to explain neutron ineterferometric experiments concerning two aspects of weak-value/measurement.
References:
J. Erhart et al., Nature Phys. 8, 185 (2012).
T. Denkmayr et al., Nat. Comm. (2014) DOI: 10.1038/ncomms5492.
Eiichiro Kokubo, National Astronomical Observatory of Japan
Simulating Formation of Terrestrial Planets
Meeting room 3, Kenkyu honkan 1F
Recent exoplanet surveys revealed that terrestrial planets are ubiquitous in the Galaxy. In the standard scenario, a planetary system forms from a protoplanetary disk that consists of gas and dust. The standard scenario of terrestrial planet formation can be divided into three stages: (1) planetesimal formation, (2) protoplanet formation, and (3) planet formation. In stage (1), planetesimals form from dust. Planetesimals are small building blocks of solid planets. Planetesimals grow by mutual collisions to protoplanets or planetary embryos in stage (2). In stage (3) terrestrial planets are formed by giant impacts among protoplanets. Today these stages are investigated mainly by numerical simulations since they includes complex and non-linear processes. In the present talk, I review the basic elementary processes of terrestrial planet formation, showing some recent numerical simulations.
Hirotada Okawa, Waseda University
On the gravitational collapse in confined geometries
Meeting room 3, Kenkyu honkan 1F
t was recently pointed out that anti-de Sitter(AdS) spacetime is unstable against gravitational collapse. The pertubation in AdS does not simply decay away and can be reflected by AdS boundary to nonlinearly interact with one another. Confinement would play an important role in the nonlinear instability. For instance, how does the gravitational collapse occur by an effective confinement? In this presentation, I would like to show our results in an asymptotic flat spacetime and discuss open problems in this field after making a brief review.
Aravind Natarajan, University of Pittsburgh, IMPU
Probes of dark matter
Meeting room 1, Kenkyu honkan 1F
Weakly Interacting Massive Particles (WIMPs) are one of the leading candidates for the dark matter of the Universe. Dark matter searches include collider, direct and indirect detection experiments. I briefly discuss how the La rge Hadron Collider can constrain theories of dark matter. I then discuss 2 cosmological probes of dark matter: (i) The cosmic microwave background and (ii) Radio observations of the nearby dwarf galaxies.
Tetsuo Hyodo, YTIP
Compositeness of hadrons and near-threshold dynamics
Seminar room, Kenkyu honkan 3F
We present the recent developments in the studies of the structure of hadron resonances, focusing on the notion of the compositeness in terms of the hadronic degrees of freedom. We discuss the model dependence of the compositeness, and show that the structure of the near-threshold bound states and resonances is model-independently determined, thanks to the low-energy universality.
Satoshi Shirai, DESY
Flavor and Minimal SUSY GUT
Meeting room 1, Kenkyu Honkan 1F
