Masato Arai, Czech Technical University in Prague
Renormalization effects on the MSSM from a calculable model of a strongly coupled hidden sector
Meeting room 1, Kenkyu honkan 1F
We investigate possible renormalization effects on the low-energy mass spectrum of the minimal supersymmetric standard model (MSSM), using a calculable model of strongly coupled hidden sector. We model the hidden sector by N=2 supersymmetric quantum chromodynamics with gauge group SU(2) x U(1) and N_f=2 matter hypermultiplets, perturbed by a Fayet-Iliopoulos term which breaks the supersymmetry down to N=0 on a metastable vacuum. In the hidden sector the Kahler potential is renormalized. Upon identifying a hidden sector modulus with the renormalization scale, and extrapolating to the strongly coupled regime using the Seiberg-Witten solution, the contribution from the hidden sector to the MSSM renormalization group flows is computed. For concreteness, we consider a model in which the renormalization effects are communicated to the MSSM sector via gauge mediation. In contrast to the perturbative toy examples of hidden sector renormalization studied in the literature, we find that our strongly coupled model exhibits rather intricate effects on the MSSM soft scalar mass spectrum, depending on how the hidden sector fields are coupled to the messenger fields. This model provides a concrete example in which the low-energy spectrum of MSSM particles that are expected to be accessible in collider experiments is obtained using strongly coupled hidden sector dynamics.
Yuji Osumi, Nagoya University
宇宙の初期ゆらぎの古典性とエンタングルメント
Meeting room 1, Kenkyu honkan 1F
宇宙背景放射の温度ゆらぎなどに見られる宇宙の初期密度ゆらぎは，インフレーション期における場の量子効果によって生じたと考えられている．しかし，宇宙背景放射の温度ゆらぎは古典的なゆらぎであり，量子力学特有の性質は今のところ見つかっていない．したがって，初期ゆらぎの量子的性質はなんらかの機構によって消えると考えられる．この発表では，ゆらぎの２点間の量子相関，いわゆるエンタングルメントを調べ，それが消える条件について議論する．
Richard Hill, University of Chicago
Universal behavior in the scattering of heavy, weakly interacting dark matter on nuclear targets
Meeting room 3, Kenkyu honkan 1F
Particles that are heavy compared to the electroweak scale (M >> m_W), and that are charged under electroweak SU(2) gauge interactions display universal properties such as a characteristic fine structure in the mass spectrum induced by electroweak symmetry breaking, and an approximately universal cross section for scattering on nuclear targets. The heavy particle effective theory framework is developed to compute these properties. As illustration, the spin independent cross section for low-velocity scattering on a nucleon is evaluated in the limit M >> m_W, including complete leading-order matching onto quark and gluon operators, renormalization analysis, and systematic treatment of perturbative and hadronic-input uncertainties.
Keiko I. Nagao, KEK
Dark Matter in Inert Triplet Models
Meeting room 1, Kenkyu honkan 1F
Since the standard model (SM) does not accommodate dark matter candidate, new physics models are expected. In the inert triplet model (ITM), we introduce one triplet scalar which does not couple to the SM fermions. In this talk I plan to talk about the signature of the DM candidates in the model.
Andrey Tayduganov
Determining the photon polarization of the $b¥to s¥gamma$ using the $B¥to K_1(1270)¥gamma¥to(K¥pi¥pi)¥gamma$ decay
Seminar hall, 4 go-kan
Recently the radiative $B$ decay to the strange axial-vector mesons, $B¥to K_1(1270) ¥gamma$, has been observed with rather large rate. This process is particularly interesting as the subsequent $K_1$ decay into its three body final state allows to determine the polarization of the gamma, which is mostly left- (right-)handed for $¥overline{B} (B)$ in the SM while various new physics models predict additional right- (left-)handed components. A new method is proposed to determine the polarization, exploiting the full Dalitz plot distribution, which seems to reduce strongly the statistical errors. In order to obtain a theoretical prediction for this polarization measurement, it is necessary to understand the hadronic $K_1 ¥to K ¥pi ¥pi$ decay channel and its uncertainties. The strong decays of the $K_1$ mesons, namely the partial wave amplitudes as well as their relative phases, are revisited in the framework of the $^3P_0$ quark-pair-creation model. Then, the result on the sensitivity of the $B¥to K_1(1270) ¥gamma$ process to the photon polarization is presented.
Tsuyoshi Houri, Osaka City University
Geometrization of Hamiltonian Dynamics and Hidden Symmetry of Space-times
Meeting room 1, Kenkyu honkan 1F
It is known that motion of free particles in curved space-times is deeply connecting with symmetry of space-times. In particular, it has been revealed that besides isometry “hidden symmetry” is important in black hole space-times since it was discovered first in Kerr space-time. Therefore it is interesting question to study how hidden symmetry works in higher-dimensional black hole space-times. In this talk, we will study hidden symmetry of five-dimensional black ring space-times together with a “Geomtrization” method. According to Maupertuis’ principle, Hamiltonian dynamics result in geodesic problems on the corresponding manifolds, which is called “Geometrization.” In the first half of this talk, beginning with a review of hidden symmetry, we will introduce the geometrization carefully. After that, hidden symmetry of five-dimensional black ring space-times will be discussed.
Kentaroh Yoshida, Kyoto University
Classical integrable structure of deformed sigma models
Meeting room 1, Kenkyu honkan 1F
We show that Yangian x quantum group symmetries are realized in two-dimensional sigma models whose target spaces are three-dimensional squashed spheres, warped AdS spaces and Schrodinger spacetimes. These symmetries enable us to develop two descriptions to describe its classical dynamics, according to the left and right symmetries. Each of the Lax pairs constructed in both ways leads to the same equations of motion. The two descriptions are related one another through a non-local map.
Kunihisa Morita, Waseda Institute for Advanced Study
時間対称化された量子力学の解釈
Seminar room, Kenkyu honkan 3F
量子力学の解釈問題において，状態の収縮を認めるか否かは重要な争点のひとつである．また，状態の収縮を認めない場合，では，物理量が測定前は明確な値をもたない物理量をもたないのに，どのようにして，測定後は明確な値をもつようになるのか，ということに答えることができなければならない．そのひとつの回答として，アハラノフらの時間対称化された量子力学（二状態ベクトル形式）をベースにした時間対称化された解釈について議論する．
坂口貴男, Brookhaven National Laboratory
電磁プローブによる重イオン衝突の研究
Seminar room, Kenkyu honkan 3F
２０００年よりＲＨＩＣで始まった重イオン衝突の実験においては、これまで生成量が小さかったために困難であった、ハード過程を利用した研究が可能となった。衝突でできた高温高密度物質と、ハード過程で散乱されたパートンの相互作用によって起きた、高横運動量ハドロンの収量の抑制は、この研究手法における大きな成果の一つであるが、その解釈を決定的にしたのが、衝突初期の情報をそのまま持ち出す単光子の測定である。 単光子は衝突初期から、系がハドロン化するまでに、連続的に放射されるため、重イオン衝突を系統的に研究する、最適のプローブである。 本講演では、重イオン衝突における単光子測定の歴史と、その測定手法、そしてRHICにおける最新の測定結果を紹介する。
Handhika Satrio Ramadhan, LIPI
Exotic Transitions in 6d Flux Compactifications
Room 345, 4 go-kan
