鈴木惇也, 東京大学
[Cosmophysics seminar] Hidden Photon ダークマター探索
Room 345, 4 go-kan 3F
ダークマターの存在はさまざまな観測結果から示唆されており、その直接探索実験は実験物理学の花形の一つとなっている。現在、ダークマターの正体として WIMP を想定し原子核反跳を捉える実験が盛んにおこなわれている。一方、それ以外に axion などの軽い粒子が非熱的に生成されるというシナリオも考えられ、その探索を目指す実験として ADMX などがある。近年、hidden photon (dark photon) も非熱的なシナリオでダークマターになりうることが指摘され、その新奇な探索手法として dish antenna を用いた方法が 提案された。それを受けて我々の研究室では、 ~ eV と ~10^{-5} eV 、２つの hidden photon 質量領域をカバーする２つの実験装置をつくり、その探索を行った。本講演ではダークマターの可能性としての hidden photon について、その実験手法と我々の探索結果についての話をおこなう。
Daisuke Harada, KEK
Phenomenology of Heavy vector-like quarks
Meeting room 1, Kenkyu honkan 1F
Ｋ中間子の崩壊におけるCPの破れについて説明するため、クォークの世代数が、少なくとも３世代以上であることが知られている。標準模型の枠内では、４世代目のクォークおよびレプトンが存在してはいけないという理論的な理由は存在しない。しかしながら、最近のＬＨＣ実験におけるヒッグス探索の結果によって、４世代目のカイラルなクォークは強く否定されている。この実験によって、４世代目のクォーク自体が否定されているわけではなく、その他の可能性として、ベクターライクフェルミオンが知られている。例えば、リトルヒッグス模型や余剰次元の模型といった様々なNew Physicsの模型において、このようなフェルミオンが導入されている。従って、このようなベクターライクフェルミオンがTeVスケールの物理の与える影響について調べることは非常に興味深い。我々の研究では、個々の模型に依存せずにベクターライクフェルミオンの効果について調べるため、有効模型を用いて、LHC実験における発見可能性やフレーバー物理に与える影響について調査した。セミナーでは、この研究成果について議論する。
Yuichiro Nakai, Harvard University
Deconstruction, Holography and Emergent Supersymmetry
Meeting room 1, Kenkyu honkan 1F In this talk, we discuss a gauge theory in a 5D warped space via the dimensional deconstruction that a higher dimensional gauge theory is constructed from a moose of 4D gauge groups. By the AdS/CFT
In this talk, we discuss a gauge theory in a 5D warped space via the dimensional deconstruction that a higher dimensional gauge theory is constructed from a moose of 4D gauge groups. By the AdS/CFT
correspondence, a 5D warped gauge theory is dual to a 4D conformal field theory (CFT) with a global symmetry. As far as physics of the gauge theory, we obtain the one-to-one correspondence between each component of a moose of gauge groups and that of a CFT. We formulate a supersymmetric extension
of deconstruction and explore the framework of natural supersymmetry in a 5D warped space – the supersymmetric Randall-Sundrum model with the IR-brane localized Higgs and bulk fermions – via the gauge moose. In this model, a supersymmetry breaking source is located at the end of the moose corresponding to the UV brane and the first two generations of squarks are decoupled. With left-right gauge symmetries in the bulk of the moose, we demonstrate realization of accidental or emergent supersymmetry of the Higgs sector in comparison with the proposed “Moose/CFT correspondence.”
Kohsaku Tobioka, Tel Aviv U., Weizmann, KEK
Probing Higgs-charm coupling, for current and future LHC
Meeting room 1, Kenkyu honkan 1F
We introduce four different types of datadriven analyses that constrain the size of the Higgscharm Yukawa coupling: (i) recasting the vectorboson associated, Vh, analyses that search for bottompair final state; (ii) the direct measurement of the total width; (iii) the search to h> J/\psi\gamma; (iv) a global fit to the Higgs signal strengths. A comparison with t\bar{t}h data allows us to show that the Higgs does not couple to quarks in a universal way. Finally, we demonstrate how the experimental collaborations can further improve our direct bound (i) using charmtagging.
Khaiming Wong, Universiti Sains Malyasia
Monopole-Antimonopole System and Vortex-ring Configurations in the Weinberg-Salam Model
Seminar room, Kenkyu honkan 3F The Georgi-Glashow model is famous for the huge families of magnetic monopole solutions, the most important of all solution is the well-known ‘t Hooft-Polyakov monopole. For the more realistic Weinberg Salam model, Nambu has demonstrated the existence of a rotating dumb-bell made of monopole and antimonopoly, connected by a flux string of neutral field.
The Georgi-Glashow model is famous for the huge families of magnetic monopole solutions, the most important of all solution is the well-known ‘t Hooft-Polyakov monopole. For the more realistic Weinberg Salam model, Nambu has demonstrated the existence of a rotating dumb-bell made of monopole and antimonopoly, connected by a flux string of neutral field.
Some years later, Cho and Maison showed the Georgi-Glashow and Weinberg-Salam model possesses exactly the same topological structure, and constructed a spherically symmetric Weinberg-Salam monopole, namely the Cho-Maison monopole. In this work we solve the Weinberg-Salam equations of motion for numerical solutions which are generalization of Nambu’s electroweak monopole and the Cho-Maison monopole. These solutions correspond to series of magnetic poles with alternating sign aligned along the z-axis, which include the monopole-antimonopole chain, monopole-antimonoploe pair, and vortex ring.
Tao Liu, The Hong Kong University of Science and Technology
New Strategies on Higgs measure measurements at pp colliders: from LHC to a 100 TeV machine
Meeting room 1, Kenkyu honkan 1F
In this talk, I will present several new Strategies on the measurements of Higgs physics, mainly including Higgs self-coupling and new Higgs resonances, at LHC and A future 100 TeV machine.
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.
