Model building for a 17 KeV neutrino

We study models with Goldstone bosons (“triplet”-Majorons, familons and Majorons with singlet Higgs fields) accomodating the 17 KeV neutrino reported by Simpson. We consider the possibility of Dirac and Majorana neutrinos. In both cases all phenomenological bounds, includin that coming from “standard” galaxy formation models, are satisfied.     

Anderson Localization for a Supersymmetric Sigma Model

We study a lattice sigma model which is expected to reflect the Anderson localization and delocalization transition for real symmetric band matrices in 3D. In this statistical mechanics model, the field takes values in a supermanifold based on the hyperbolic plane. The existence of a diffusive phase in 3 dimensions was proved in Disertori et al. (Commun. Math. Phys., doi:, 2009) [2] for low temperatures. Here we prove localization at high temperatures for any dimension d ≥ 1. Our analysis uses Ward identities coming from internal supersymmetry.     

A Nonperturbative Regularization of the Supersymmetric Schwinger Model

It is shown that noncommutative geometry is a nonperturbative regulator which can manifestly preserve a space supersymmetry and a supergauge symmetry while keeping only finite number of degrees of freedom in the theory. The simplest N= 1 case of the U(1) supergauge theory on the sphere is worked out in detail. Received: 15 March 1999 / Accepted: 8 April 1999     

The quasi-fixed Minimal Supersymmetric Standard Model

The infra-red fixed points are determined for all the parameters of the MSSM. They dominate the renormalisation group running when the top-Yukawa is in the quasi-fixed point regime (i.e. large at the GUT scale). We examine this behaviour analytically, by solving the full set of one-loop renormalisation group equations in the approximation that the electroweak contributions are negligible, and also numerically. We find the quasi-fixed points for the top-quark trilinear couplings; A_Uα3=A_U3α=−0.59m_g independently of the input parameters at the unification scale. All the remaining parameters are significantly focused towards their true fixed points at the weak scale. We examine how this increases the predictivity of the MSSM in this regime.     

Determinant Representations of Correlation Functions for the Supersymmetric t-J Model

Working in the F-basis provided by the factorizing F-matrix, the scalar products of Bethe states for the supersymmetric t-J model are represented by determinants. By means of these results, we obtain determinant representations of correlation functions for the model.     

Neutrino oscillation beyond the Standard Model

A short review of the theory of neutrino oscillation for non-standard neutrino interaction (NSI) which may exist at low energy is presented. Depending on the NSI, initial neutrino states can be mixed and final oscillation rates not necessarily factorize.     

A Unified Empirical Model for Quasielastic Interactions of Neutrino and Antineutrino with Nuclei

Physics of Particles and Nuclei Letters - We propose a simple empirical model for evaluating the quasielastic neutrino- and antineutrino-nucleus cross sections, based on the conventional...     

Two-Photon Entanglement in a Two-Mode Supersymmetric Model

We will study entangled two-photon states generated from a two-mode supersymmetric model and quantify degree of entanglement in terms of the entropy of entanglement. The influences of the nonlinearity on the degree of entanglement is also examined, and it is shown that amount of entanglement increase with increasing the nonlinear coupling constant. PACS numbers: 03.67.-a, 03.67.Mn.     

Solar Neutrino Problem in Seesaw Model

A specific texture for the Dirac and Majorana mass matrices in the seesaw model leading to a pair of almost degenerate neutrinos is discussed. This texture can be obtained by imposing a global U(1) symmetry. This model could solve the solar neutrino problem through the MSW mechanism and offer the hot component of the dark matter of the universe which requires Σm_vi = 7 eV.     

A Note on the Bethe Ansatz Solution of the Supersymmetric t-J Model

The three different sets of Bethe ansatz equations describing the Bethe ansatz solution of the supersymmetric t-J model are known to be equivalent. Here we give a new, simplified proof of this fact which relies on the properties of certain polynomials. We also show that the corresponding transfer matrix eigenvalues agree.     

中微子几何混合模型与轻子和重子数产生

在这一报告中将报告我和BABU教授合作的在hep-ph/0507217一文中有关中微子混合研究结果. 目前中微子实验数据所决定的混合角可归结为几何混合状况:sin²θ₁₂=1/3,sin²θ₂₃=1/2, 和sin²θ₁₃=0. 我们在这一工作中建立了能实现这一几何混合的可重整化模型. 模型以非阿贝尔非连续群A₄为描述中微子不同代混合的对称性. 这类模型对中微子质量有很强的限制. 而且能很自然地由轻子数破坏产生重子不对称的实验观测值. 很有趣的是这类模型中出现在轻子不守恒和无中微子双beta衰变中的相位是一样的.     

Neutrino Oscillations in Caianiello's Quantum Geometry Model

Neutrino flavor oscillations are analyzed in the framework of Quantum Geometry model proposed by Caianiello. In particular, we analyze the consequences of the model for accelerated neutrino particles that experience an effective Schwarzschild geometry modified by the existence of an upper limit on the acceleration, which implies a violation of the equivalence principle. We find a shift of quantum-mechanical phase of neutrino oscillations, which depends on the energy of neutrinos as E³. Implications on atmospheric and solar neutrinos are discussed.     

超对称Sinh-Gordon模型的边界反射因子

利用微扰论研究了带有一个可积边界条件的sinh-Gordon模型,检验了精确反射因子的一圈修正, 并构造了玻色子和费米子传播子.     

Enhancing Gauge Symmetries of Non-Abelian Supersymmetric Chern-Simons Model

In this article, we study gauge symmetries of the Non-Abelian Supersymmetric Chern-Simons model (SCS) of SU(2) group at (2+1)-dimensions in the framework of the formalism of constrained systems. Since, broken gauge symmetries in this physical system lead to the presence of nonphysical degrees of freedom, the Non-Abelian SCS model is strictly constrained to second-class constraints. Hence, by introducing some auxiliary fields and using finite order BFT method, we obtain a gauge symmetric model by converting second-class constraint to first-class ones. Ultimately, the partition function of the model is obtained in the extended phase space.     

Consequence for Wavefunction Collapse Model of the Sudbury Neutrino Observatory Experiment

It is shown that data on the dissociation rate of deuterium obtained in an experiment at the Sudbury Neutrino Observatory provides evidence that the Continuous Spontaneous Localization wavefunction collapse model should have mass–proportional coupling to be viable.     

A Bi-Hamiltonian Supersymmetric Geodesic Equation

A supersymmetric extension of the Hunter–Saxton equation is constructed. We present its bi-Hamiltonian structure and show that it arises geometrically as a geodesic equation on the space of superdiffeomorphisms of the circle that leave a point fixed endowed with a right-invariant metric.      

Search for a lighter Higgs boson in the Next-to-Minimal Supersymmetric Standard Model

Following the discovery of the Higgs boson with a mass of approximately 125 Ge V at the LHC, many studies have been performed from both the theoretical and experimental viewpoints to search for a new Higgs Boson that is lighter than 125 Ge V. We explore the possibility of constraining a lighter neutral scalar Higgs boson h_1 and a lighter pseudo-scalar Higgs boson a_1 in the Next-to-Minimal Supersymmetric Standard Model by restricting the next-to-lightest scalar Higgs boson h_2 to be the one observed at the LHC after applying the phenomenological constraints and those from experimental measurements. Such lighter particles are not yet completely excluded by the latest results of the search for a lighter Higgs boson in the diphoton decay channel from LHC data. Our results show that some new constraints on the Next-to-Minimal Supersymmetric Standard Model could be obtained for a lighter scalar Higgs boson at the LHC if such a search is performed by experimental collaborations and more data. The potentials of discovery for other interesting decay channels of such a lighter neutral scalar or pseudo-scalar particle are also discussed.