14562531
On neutrino masses and mixings from extra dimensions
Abstract In the framework of a Kaluza-Klein type theory with the Standard Model fields localized on a 4-dimensional section while gravity propagates in a full 4+ δ -dimensional space-time, we examine a mechanism of naturally small neutrino mass generation through couplings of the Standard Model singlet fermion(s) living also in the full space-time. A numerical study is carried out on the charged current universality constraint from the ratio of pion decay partial widths. The bounds obtained on the fundamental mass scale could be stringent.
18810830
The sTB-B hierarchy
Abstract We construct a new supersymmetric two boson (sTB-B) hierarchy and study its properties. We derive the conserved quantities and the Hamiltonian structures (proving the Jacobi identity) for the system. We show how this system gives the sKdV-B equation and its Hamiltonian structures upon appropriate reduction. We also describe the zero curvature formulation of this hierarchy both in the superspace as well as in components.
123610301
The hamiltonian structures of the KP hierarchy
Abstract We obtain the two hamiltonian structures of the KP hierarchy following the method of Drinfeld and Sokolov. We point out how the second structure of Drinfeld and Sokolov needs to be modified in the present case. We briefly comment on the connection between these structures and the W 1+∞ algebra.
119380448
DYNAMICAL SUPERSYMMETRY
We show, in a simple quantum mechanical model, how a theory can become supersymmetric in the presence of interactions even when the free theory is not. This dynamical generation of supersymmetry relaxes the condition on the equality of masses of the superpartners which would be of phenomenological interest.
39204644
Thermal Operator and Cutting Rules at Finite Temperature and Chemical Potential
In the context of scalar field theories, both real and complex, we derive the cutting description at finite temperature (with zero/finite chemical potential) from the cutting rules at zero temperature through the action of a simple thermal operator. We give an alternative algebraic proof of the largest time equation which brings out the underlying physics of such a relation. As an application of the cutting description, we calculate the imaginary part of the one-loop retarded self-energy at zero/finite temperature and finite chemical potential and show how this description can be used to calculate the dispersion relation as well as the full physical self-energy of thermal particles.
120503298
Systematic expansion for compact QED near weak coupling
119202936
Inverse seesaw neutrino signatures at the LHC and ILC
We study the collider signature of pseudo-Dirac heavy neutrinos in the inverse seesaw scenario, where the heavy neutrinos with mass at the electroweak scale can have sizable mixings with the Standard Model neutrinos, while providing the tiny light neutrino masses by the inverse seesaw mechanism. Based on a simple, concrete model realizing the inverse seesaw, we fix the model parameters so as to reproduce the neutrino oscillation data and to satisfy other experimental constraints, assuming two typical flavor structures of the model and the different types of hierarchical light neutrino mass spectra. With the fixed parameters in this way, we analyze the heavy neutrino signal at the LHC through tri-lepton final state with large missing energy and at the ILC through a single lepton plus di-jet with large missing energy. We find that in some cases, the heavy neutrino signal can be observed with a large statistical significance via different flavor charged lepton final states. Therefore, we can not only discover the heavy neutrinos in the future but also obtain a clue to reveal the origin of the small neutrino mass and flavor mixing.
119194703
Phenomenological implications of S-duality symmetry
Abstract It is proposed that S -duality is a fundamental symmetry of nature which is spontaneously broken. Axion and dilaton are identified with the doublet of the S -duality symmetry group SL ( 2 , R ) . The symmetry is broken at a high scale corresponding to the experimentally estimated axion decay constant f χ . The symmetry breaking mechanism is discussed in analogy with PCAC in pion physics. S -duality invariant interactions of fermions with axion and dilaton doublet are introduced. The symmetry breaking mechanism contributes negligibly small corrections to fermion masses in the QCD sector. Inspired by universality in string theory, the S -duality invariant interaction of the axion–dilaton doublet to QCD fermions is proposed to generalize to all fermions. Phenomenological consequences of this broken symmetry are explored.
35140437
Hard thermal effective action in QCD through the thermal operator
We derive in a simple way the well-known hard thermal effective action for QCD through the application of the thermal operator to the zero temperature retarded Green's functions. This derivation also clarifies the origin of important properties of the hard thermal effective action, such as the manifest Lorentz and gauge invariance of its integrand, by relating them directly to the properties of the corresponding zero temperature effective action in the hard regime.
119040018
Large gauge invariance and finite temperature
In this talk, I summarize the status of our understanding of the puzzle of large gauge invariance at finite temperature.
15109221
Supersymmetric and Deformed Harry Dym hierarchies
In this talk, we describe our recent results on the supersymmetrization of the Harry Dym hierarchy as well as a newly constructed deformed Harry Dym hierarchy which is integrable with two arbitrary parameters. In various limits of these parameters, the deformed hierarchy reduces to various known integrable systems.