永江知文, 京都大学理学研究科
[JAEA先端研, KEK理論センターJ-PARC分室共催セミナー] S-2Sスペクトロメーターを用いたマルチ・ストレンジネス多体系の精密分光
JAEA先端基礎交流棟3階302号室 J-PARC E05実験では、(K-,K+)反応を用いてストレンジネス-2のバリオン多体系であるグザイ・ハイパー核の束縛状態を、エネルギースペクトル上でピークとして観測することを目標としています。
J-PARC E05実験では、(K-,K+)反応を用いてストレンジネス-2のバリオン多体系であるグザイ・ハイパー核の束縛状態を、エネルギースペクトル上でピークとして観測することを目標としています。
そのピーク位置から束縛エネルギーを求め、ピークのエネルギー幅からΞN-ΛΛの結合の強さの情報を引き出します。この測定のため、現在、立体角60msr、運動量分解能5×10^-4の性能を目指すS-2Sスペクトロメーターと呼ぶ新しい磁気スペクトロメーター系を建設中です。
本セミナーでは、その建設状況とこれを使った実験プログラムについて紹介します。
Kohei Kamada, Ecole Polytechnique Federale de Lausanne
Inflationary cosmology and Standard Model Higgs
Meeting Room 1, Kenkyu Honkan 1F
After the discovery of Higgs particle at LHC, we can now say that the Standard Model of particle physics (SM) is completed. However, we cannot still explain the Universe with the SM as it is. In this talk, I will focus on inflation , which is now an (almost) indispensable ingredient in the modern cosmology, and explain the possible ways to drive inflation by the SM Higgs field itself. In particular, I will explain the self consistency of these scenarios and the relation to the electroweak vacuum stability. If time permitted, I will also talk about the electroweak vacuum stability during and after inflation in the case where inflation is driven by other sector than the SM.
David Kubiznak, Perimeter Institute
P-V criticality of AdS black holes
Seminar room, Kenkyu honkan 3F
Treating the cosmological constant as a thermodynamic pressure and its conjugate quantity as thermodynamic volume, we reconsider the critical behavior of AdS black holes. We complete the analogy between the thermodynamics of charged AdS black holes and that of the liquid/gas system. The corresponding critical point occurs at a point of divergence of specific heat at constant pressure and is characterized by critical exponents that coincide with those of the Van der Waals fluid. For more complicated black holes, phenomena like reentrant phase transitions, triple points, and even that of the isolated critical points are observed.
Koutarou Kyutoku, RIKEN iTHES
Dynamical mass ejection from black hole-neutron star binaries
Seminar room, Kenkyu honkan 3F In recent years, mass ejection from compact binary coalescences has been getting a lot more attention. Neutron-rich material ejected from neutron stars during such a coalescence event are increasingly recognized as the most promising site of the rapid-process (r-process) nucleosynthesis. Mass ejection will also be the primary agent driving electromagnetic radiation from compact binary mergers, or electromagnetic counterparts to gravitational waves.
In recent years, mass ejection from compact binary coalescences has been getting a lot more attention. Neutron-rich material ejected from neutron stars during such a coalescence event are increasingly recognized as the most promising site of the rapid-process (r-process) nucleosynthesis. Mass ejection will also be the primary agent driving electromagnetic radiation from compact binary mergers, or electromagnetic counterparts to gravitational waves.
Simultaneous detection of electromagnetic counterparts with gravitational waves is eagerly desired, particularly for accurate source localization. Because mass ejection from black hole-neutorn star binaries are violent phenomena involving disruption of neutron stars, numerical relativity is the only reliable approach for theoretical investigation. In this talk, we present our latest results for dynamical mass ejection from the black hole-neutron star binary merger obtained by numerical-relativity simulations.
We also discuss possible electromagnetic counterparts from the anisotropic dynamical ejecta from black hole-neutron star binaries.
Chong-Sun Chu, National Tsing Hua University, Taiwan
On the gravitational loop effects on the cosmological constant
Meeting Room 1, Kenkyu Honkan 1F
In this talk I will consider a 4 dimensional model where the infrared effect at one loop of the graviton provides a screening on the cosmological constant
Michael E. Peskin, SLAC
Secrets of the Higgs Boson
Meeting room 1, Kenkyu honkan 1F
In two and a half years since the discovery of the Higgs boson, many particle physicists have gone the whole route from skepticism about the existence of this particle to contentment with its Standard-Model-like properties. In reality, we have hardly begun to explore the secrets of the Higgs boson. In this lecture, I will review the coming program of precision measurement of the Higgs boson properties. I will discuss the level of precision needed in this study to test theoretical models, the prospects for high-precision theoretical calculation of the Standard Model reference values, and the prospects for high-precision measurements at the LHC and the ILC.
George Zoupanos, National Technical U
Reduction of Couplings in Quantum Field Theories with applications in Finite Theories and the MSSM
Meeting Room 1, Kenkyu Honkan 1F
We apply the method of reduction of couplings in a Finite Unified Theory (FUT) and in the MSSM. The method consists on searching for renormalization group invariant relations among couplings of a renormalizable theory holding to all orders in perturbation theory. It has a remarkable predictive power since, at the unication scale, it leads to relations between gauge and Yukawa couplings in the dimensionless sectors and relations involving the trilinear terms and the Yukawa couplings, as well as a sum rule among the scalar masses and the unified gaugino mass in the soft breaking sector. In both the MSSM and the FUT model we predict the masses of the top and bottom quarks and the light Higgs in remarkable agreement with the experiment. Furthermore we also predict the masses of the other Higgses, as well as the supersymmetric spectrum, both being in very comfortable agreement with the LHC bounds on Higgs and supersymmetric particles.
Markus Rummel, U Oxford
Dark Matter and Dark Radiation from Axion-Like-Particles
Meeting room 3, Kenkyu honkan 1F
First, we discuss the possibility of explaining the 3.5 keV line through dark matter decaying to axion-like particles that subsequently convert to photons in astrophysical magnetic fields. This model is consistent with all present observations of the 3.5 keV line, including galaxy clusters, spiral and dwarf galaxies and the galactic centre. Then, we discuss how a Cosmic-ALP-background can explain the excess of Soft X-rays in galaxy clusters.
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
