119287518
Unitary coupled-channels model for three-mesons decays of heavy mesons
In this study, a unitary coupled-channels model is presented for investigating the decays of heavy mesons and excited meson states into three light pseudoscalar mesons. The model accounts for the three-mesons final state interactions in the decay processes, as required by both the three-body and two-body unitarity conditions. In the absence of the Z-diagram mechanisms that are necessary consequences of the three-body unitarity, our decay amplitudes are reduced to a form similar to those used in the so-called isobar-model analysis. We apply our coupled-channels model to the three-pions decays of α1(1260), π2(1670), π2(2100), and D0 mesons, and show that the Z-diagram mechanisms can contribute to the calculated Dalitz plot distributions by as much as 30% in magnitudes in the regions where f0(600), ρ(770), and f2(1270) dominate the distributions. Also, by fitting to the same Dalitz plot distributions, we demonstrate that the decay amplitudes obtained with the unitary model and the isobar model can be rather different, particularly in the phase that plays a crucial role in extracting the CKM CP-violating phase from the data of B meson decays. Our results indicate that the commonly used isobar model analysis must be extended to account for the final state interactions required bymore » the three-body unitarity to reanalyze the three-mesons decays of heavy mesons, thereby exploring hybrid or exotic mesons, and signatures of physics beyond the standard model.« less
85451103
Extraction of Meson Resonances from Three-pions Photo-production Reactions
We have investigated the model dependence of meson resonance properties extracted from the Dalitz-plot analysis of the three-pions photoproduction reactions on the nucleon. Within a unitary model developed in Phys. Rev. D 84, 114019 (2011), we generate Dalitz-plot distributions as data to perform an isobar model fit that is similar to most of the previous analyses of three-pion production reactions. It is found that the resonance positions from the two models agree well when both fit the data accurately, except for the resonance poles near branch points. The residues of the resonant amplitudes extracted from the two models and by the usual Breit-Wigner procedure agree well only for the isolated resonances with narrow widths. For overlapping resonances, most of the extracted residues could be drastically different. Our results suggest that even with high precision data, the resonance extraction should be based on models within which the amplitude parametrization is constrained by three-particle unitarity condition.
117947270
Meson spectroscopy with unitary coupled-channels model for heavy-meson decay into three mesons
We develop a model for describing excited mesons decay into three mesons. The properties of the excited mesons can be extracted with this model. The model maintains the three-body unitarity that has been missed in previous data analyses based on the conventional isobar models. We study an importance of the three-body unitarity in extracting hadron properties from data. For this purpose, we use the unitary and isobar models to analyze the same pseudo data of gamma p -> pi+pi+pi-n, and extract the properties of excited mesons. We find a significant difference between the unitary and isobar models in the extracted properties of excited mesons, such as the mass, width and coupling strength to decay channels.
122375456
Renormalization group analysis of nuclear current operators
A Wilsonian renormalization group (WRG) equation for nuclear current operators in two-nucleon systems is derived. Nuclear current operators relevant to low-energy Gamow-Teller transitions are analyzed using the WRG equation. We employ the axial two-body current operators from phenomenological models and heavy-baryon chiral perturbation theory, which are quite different from one another in describing small-scale physics. After reducing the model space of the operators using the WRG equation, we find that there still remains a significant model dependence at {lambda}=200 MeV, where {lambda} is the sharp cutoff specifying the size of the model space. A model-independent effective current operator is found at a rather small cutoff value, {lambda}=70 MeV. By simulating the effective current operator at {lambda}=70 MeV, we obtain a current operator based on a pionless theory, thereby arguing that an equivalence relation exists between nuclear current operators of phenomenological models and those of effective field theories.
119109289
Explanation of the More Effective Effective Field Theory
We show that the so-called more effective effective field theory (MEEFT) is essentially equivalent to the proper nuclear effective field theory (NEFT) in describing low-energy electroweak processes in nuclei. A key to understanding their equivalence is the relation between aN EFT-based NN -potential and a phenomenological potential through the Wilsonian renormalization group equation. We also discuss an important advantage of MEEFT.
14437805
Consideration of nuclear forces from the viewpoint of the renormalization group: Relation of nuclear forces between phenomenological approach and nuclear effective field theory
A relation between nuclear forces derived using a phenomenological approach and nuclear effective field theory (NEFT) is proposed from a renormalization group point of view. A phenomenological nuclear force (V ph ) and an NEFT-based NN-potential (V EFT ) are satisfactorily related to each other through the Wilsonian renormalization group (WRG) method. It is clearly shown that use of the simple contact interactions in NEFT is adequate to simulate small scale phenomena, and that an NEFT-based NN-potential (V EFT ) is free from dependence on the model used to describe small scale phenomena. We study the characteristics of V EFT from a WRG point of view, emphasizing points that have not previously been fully recognized. We also use the V low k method and a unitary transformation method to relate V ph to V EFT . It is found that they are not appropriate for this purpose.
123970827
Gravity Dual of Spatially Modulated Phase
11991557
Off-shell crosscap state and orientifold planes with background dilatons
Abstract We show that a non-trivial dilaton condensation alters the dimensions of orientifold planes. An off-shell crosscap state which naturally interpolates between the usual on-shell crosscap states and their T-duals plays an important role in the analysis. We present an explicit representation of the off-shell crosscap state on an RP 2 worldsheet in the gauge in which the worldsheet curvature in the bulk of the fundamental region of the RP 2 vanishes. We show that the non-trivial dilaton condensation reproduces the correct descent relation among orientifold plane tensions.
5204481
D0-brane recoil revisited
One-loop string scattering amplitudes computed using the standard D0-brane conformal field theory (CFT) suffer from infrared divergences associated with recoil. A systematic framework to take recoil into account is the worldline formalism, where fixed boundary conditions are replaced by dynamical D0-brane worldlines. We show that, in the worldline formalism, the divergences that plague the CFT are automatically cancelled in a non-trivial way. The amplitudes derived in the worldline formalism can be reproduced by deforming the CFT with a specific ``recoil operator'', which is bilocal and different from the ones previously suggested in the literature.
120851453
Rydberg-atom cavity detector for dark matter axion search in Kyoto*
A new detection method to search for dark matter axions was developed with Rydberg atoms in resonant cavities. Principle of the method and the development status of the experimental apparatus based on this scheme are presented and discussed.
18217443
Extension of boundary string field theory on disc and RP 2 worldsheet geometries
We present a construction of open-closed string field theory based on disc and RP 2 geometries. Finding an appropriate BRS operator in the case of the RP 2 geometry, we generalize the background independent open string field theory (or boundary string field theory) of Witten on a unit disc. The coupling constant flow at the closed string side is driven by the scalar operator inserted at the nontrivial loop of RP 2 . We discuss the off-shell extension of the boundary/crosscap states. Our construction provides an interpolation of orientifold planes of various dimensions as well as that of D-branes.