2592484
A General Treatment of Oblique Parameters
A re-examination is made of one-loop oblique electroweak corrections. General definitions are given of the oblique parameters without reference to any q2 expansion scheme. The old oblique parameters S, T and U are defined as differences of gauge boson vacuum polarization Π functions and suffice for describing certain observable ratios on the Z peak and the ρ parameter at q2 = 0. Regarding the new oblique parameters V, W and X, the first two are defined in terms of differences of Π functions as well as the wave function renormalization of the corresponding weak boson, and the third in terms of the difference of differences of two Π functions for γ - Z mixing. Explicit expressions for measurable quantities involving all six oblique parameters are given and experimental bounds are obtained on the latter, some for the first time. A review of these constraints suggests that the linear approximation of Peskin and Takeuchi is robust.
31086876
Stringent low-energy mass constraints in no-scale supergravity.
Spectacular mass constraints are shown to exist at low energies in minimal no-scale supergravity theories. The top quark cannot be too light, the lowest-lying Higgs particle cannot be too heavy, and the pseudoscalar Higgs boson must weigh nearly a quarter as much as the gluino.
121584805
Current-commutators and high energy hadron production in e+e− annihilation
Abstract We consider the asymptotic behavior of the structure-functions for the process e + e − → H + everything (where H is a detectable hadron) in terms of commutators involving the electromagnetic current.
125018064
Supersymmetry working group report, 'From strings to LHC' workshop, Goa, (January, 2007)
122353884
Parton description of the forward peak in single particle electroproduction with highly virtual photons
The parton mode or the reaction eN→eAB (N = nucleon, A, B = hadrons) in the fixed ω Bj limit is used to discuss the width of the corresponding forward peak as a function of the photon mass.
119370491
Oblique corrections and the quadratic approximation in electroweak precision testing
This paper is withdrawn. A revised and expanded version of this work is available as hep-ph/9603323.
121043298
On the construction of supersymmetric quantum mechanical Hamiltonian
Starting from an arbitrary supersymmetric quantum mechanical Hamilonian (SSQM) (with unbroken spersymmetry) we construct a sequence of SSQM Hamiltonians, each one having the same energy spectrum as the original one with different eigenvectors. The alogorithm developed here is verified for a transcendental type superpotential.
8406718
Motion of a spin-½ particle in shape invariant scalar and magnetic fields
We study the motion of a spin-½ particle in a scalar as well as a magnetic field within the framework of supersymmetric quantum mechanics. We also introduce the concept of shape invariant scalar and magnetic fields and it is shown that the problem admits exact analytical solutions when such fields are considered.
119136395
Exact solutions of the (2+1) Dimensional Dirac equation in a constant magnetic field in the presence of a minimal length
We study the (2+1) dimensional Dirac equation in an homogeneous magnetic field (relativistic Landau problem) within a minimal length, or generalized uncertainty principle -GUP-, scenario. We derive exact solutions for a given explicit representation of the GUP and provide expressions of the wave functions in the momentum representation. We find that in the minimal length case the degeneracy of the states is modified and that there are states that do not exist in the ordinary quantum mechanics limit (\beta -->0). We also discuss the mass-less case which may find application in describing the behavior of charged fermions in new materials like Graphene.
115157994
Non-hermitian quantum mechanics in non-commutative space
AbstractA recent investigation of the possibility of having a 
$\mathcal{PT}$
-symmetric periodic potential in an optical lattice stimulated the urge to generalize non-hermitian quantum mechanics beyond the case of commutative space. We thus study non-hermitian quantum systems in non-commutative space as well as a 
$\mathcal{PT}$
-symmetric deformation of this space. Specifically, a 
$\mathcal{PT}$
-symmetric harmonic oscillator together with an iC(x1+x2) interaction are discussed in this space, and solutions are obtained. We show that in the 
$\mathcal{PT}$ 
deformed non-commutative space the Hamiltonian may or may not possess real eigenvalues, depending on the choice of the non-commutative parameters. However, it is shown that in standard non-commutative space, the iC(x1+x2) interaction generates only real eigenvalues despite the fact that the Hamiltonian is not 
$\mathcal{PT}$
-symmetric. A complex interacting anisotropic oscillator system also is discussed.
121137215
Novel perturbation expansion for the Langevin equation
We discuss the randomly driven systemdx/dt= -W(x) +f(t), wheref(t) is a Gaussian random function or stirring force with〈f(t)f(t′)〉=2δ(t−t′), andW(x) is of the formgx1+2δ. The parameterδ is a measure of the nonlinearity of the equation. We show how to obtain the correlation functions〈x(t)f(t′)〉···x(t(n))〉f as a power series inδ. We obtain three terms in theδ expansion and show how to use Padé approximants to analytically continue the answer in the variableδ. By using scaling relations, we show how to get a uniform approximation to the equal-time correlation functions valid for allg andδ.