Showing papers on "Superpotential published in 1993"
TL;DR: In this paper, the superpotential is not renormalized in perturbation theory but receives non-perturbative corrections, which are not generic functions of the fields consistent with the symmetries.
502 citations
TL;DR: In this paper, a simple mechanism for solving the μ-problem in the context of minimal low-energy supergravity models is proposed, based on the appearance of non-renormalizable couplings in the superpotential.
192 citations
TL;DR: In this article, an extensive search for a class of flipped SU(5) models built within the free fermionic formulation of the heterotic string is presented, and a set of algorithms which constitute the basis for a computer program capable of generating systematically the massless spectrum and the superpotential of all possible models within the class we consider.
152 citations
TL;DR: In this paper, the authors propose a simple mechanism for solving the $mu$ problem in the context of minimal low-energy supergravity models, based on the appearance of non-renormalizable couplings in the superpotential.
Abstract: We propose a simple mechanism for solving the $\mu$ problem in the context of minimal low--energy supergravity models. This is based on the appearance of non--renormalizable couplings in the superpotential. In particular, if $H_1H_2$ is an allowed operator by all the symmetries of the theory, it is natural to promote the usual renormalizable superpotential $W_o$ to $W_o+\lambda W_o H_1H_2$, yielding an effective $\mu$ parameter whose size is directly related to the gravitino mass once supersymmetry is broken (this result is maintained if $H_1H_2$ couples with different strengths to the various terms present in $W_o$). On the other hand, the $\mu$ term must be absent from $W_o$, otherwise the natural scale for $\mu$ would be $M_P$. Remarkably enough, this is entirely justified in the supergravity theories coming from superstrings, where mass terms for light fields are forbidden in the superpotential. We also analyse the $SU(2)\times U(1)$ breaking, finding that it takes place satisfactorily. Finally, we give a realistic example in which supersymmetry is broken by gaugino condensation, where the mechanism proposed for solving the $\mu$ problem can be gracefully implemented.
135 citations
TL;DR: Couplings that may appear in the superpotential of the supersymmetric extension of thestandard model but which do not occur in the standard model itself are examined.
Abstract: Couplings that may appear in the superpotential of the supersymmetric extension of the standard model but which do not occur in the standard model itself are examined. Experimental constraints on these couplings are examined in the context of natural assumptions on their values. Additional discrete symmetries are considered in cases where the natural values exceed the experimental constraints.
91 citations
TL;DR: In this paper, the authors developed techniques to compute higher loop string amplitudes for twisted $N=2$ theories with c=3$ (i.e. the critical case).
Abstract: We develop techniques to compute higher loop string amplitudes for twisted $N=2$ theories with $\hat c=3$ (i.e. the critical case). An important ingredient is the discovery of an anomaly at every genus in decoupling of BRST trivial states, captured to all orders by a master anomaly equation. In a particular realization of the $N=2$ theories, the resulting string field theory is equivalent to a topological theory in six dimensions, the Kodaira--Spencer theory, which may be viewed as the closed string analog of the Chern--Simon theory. Using the mirror map this leads to computation of the `number' of holomorphic curves of higher genus curves in Calabi--Yau manifolds. It is shown that topological amplitudes can also be reinterpreted as computing corrections to superpotential terms appearing in the effective 4d theory resulting from compactification of standard 10d superstrings on the corresponding $N=2$ theory. Relations with $c=1$ strings are also pointed out.
64 citations
TL;DR: In this article, it was shown that the theory of pure topological gravity (without topological matter) is equivalent to the theory with quadratic superpotential (without metric fields and ghosts) of the Landau-Ginzburg theory.
Abstract: It is argued that gravitational descendants in the theory of topological gravity coupled to topological Landau-Ginzburg theory (not necessarily conformal) can be constructed from matter fields alone (without metric fields and ghosts). In this sense topological gravity is “induced.” We discuss the mechanism of this effect (that turns out to be connected with K. Saito's higher residue pairing: Ki(σi(Φ1),Φ2)=K0(Φ1,Φ2)), and demonstrate how it works in a simplest nontrivial example: correlator on a sphere with four marked points. We also discuss some results on k-point correlators on a sphere. From the idea of “induced” topological gravity it follows that the theory of “pure” topological gravity (without topological matter) is equivalent to the “trivial” Landau-Ginzburg theory (with quadratic superpotential).
53 citations
TL;DR: The semiclassical WKB approximation method is reexamined in the context of nonrelativistic quantum-mechanical bound-state problems with broken supersymmetry (SUSY) and it is shown that to leading order in [h bar], the BSWKB condition yields exact energy eigenvalues for shape-invariant potentials with broken SUSY which are known to be analytically solvable.
Abstract: The semiclassical WKB approximation method is reexamined in the context of nonrelativistic quantum-mechanical bound-state problems with broken supersymmetry (SUSY). This gives rise to an alternative quantization condition (denoted by BSWKB) which is different from the standard WKB formula and also different from the previously studied supersymmetric (SWKB) formula for unbroken SUSY. It is shown that to leading order in [h bar], the BSWKB condition yields exact energy eigenvalues for shape-invariant potentials with broken SUSY (harmonic oscillator, Poeschl-Teller I and II) which are known to be analytically solvable. Further, we show explicitly that the higher-order corrections to these energy eigenvalues, up to sixth order in [h bar], vanish identically. We also consider a number of examples of potentials with broken supersymmetry that are not analytically solvable. In particular, for the broken SUSY superpotential [ital W]=[ital Ax][sup 2[ital d]] [[ital A][gt]0, [ital d]=(integer)], we evaluate contributions up to the sixth order and show that these results are in excellent agreement with numerical solutions of the Schroedinger equation. While the numerical BSWKB results in lowest order are not always better than the corresponding WKB results, they are still a considerable improvement because they guarantee equality of the corresponding energy eigenvalues for the supersymmetricmore » partner potentials [ital V][sub +] and [ital V][sub [minus]]. This is of special importance in those situations where these partner potentials are not related by parity.« less
52 citations
TL;DR: In this paper, the problem of generation mixing in realistic superstring derived standard-like models, constructed in the free fermionic formulation, was examined and a Cabibbo angle of the correct order of magnitude was obtained.
43 citations
TL;DR: In this paper, a simple transformation method permitting the generation of exactly solvable quantum mechanical potentials from special functions solving second-order differential equations is reviewed, and the relationship of this method to the determination of supersymmetric quantum mechanical superpotentials is discussed.
Abstract: A simple transformation method permitting the generation of exactly solvable quantum mechanical potentials from special functions solving second-order differential equations is reviewed. This method is applied to Gegenbauer polynomials to generate an attractive radial potential. The relationship of this method to the determination of supersymmetric quantum mechanical superpotentials is discussed, and the superpotential for the radial potential is also derived.
35 citations
TL;DR: In this article, the superpotential is not renormalized in perturbation theory but receives non-perturbative corrections, which are generic functions of the fields consistent with the symmetries.
Abstract: We give an intuitive proof of a new non-renormalization theorem in supersymmetric field theories. It applies both perturbatively and non-perturbatively. The superpotential is not renormalized in perturbation theory but receives non-perturbative corrections. However, these non-perturbative corrections are {\it not} generic functions of the fields consistent with the symmetries. Certain invariant terms are not generated. This violation of naturalness has applications to dynamical supersymmetry breaking.
TL;DR: In this article, the authors construct several analytically solvable examples of broken supersymmetry in non-relativistic quantum mechanics, motivated from known shape-invariant potentials obeying unbroken supersymmetric and are obtained from them via suitable mapping procedures.
01 Jan 1993
TL;DR: A supersymmetric extension of a class of quantum scalar field theories is constructed in this paper in an abstract form, and a family of super-symmetric extensions of a subclass of scalar fields can be found in this paper.
Abstract: A family of supersymmetric extensions of a class of quantum scalar field theories is constructed in an abstract form.
TL;DR: In this paper, the quantum conservation laws in the N = 1 and N = 2 supersymmetric sine-Gordon theories were investigated based on perturbation theory formulated in superspace.
TL;DR: In this article, it was shown that a single uncharged chiral superfield, canonically coupled to N = 1 supergravity with vanishing superpotential, naturally drives inflation in the early universe for a class of simple Kahler potentials.
TL;DR: In this article, the authors point out a specific link between a recently proposed quantum deformation approach and supersymmetric quantum mechanics, and show that, under a certain q-dependence of the superpotentials, the proposed q-deformation gives rise to a standard Witten superymmetric model.
Abstract: We point out a specific link between a recently proposed quantum deformation approach and supersymmetric quantum mechanics. In fact, we show that, under a certain q-dependence of the superpotentials, the proposed q-deformation gives rise to a standard Witten supersymmetric model. The context of a harmonic oscillator-like system is considered.
TL;DR: In this article, the superpotential of the Lienard-Wiechert electromagnetic field generated by an arbitrarily moving charge in the Minkowski space was obtained using Newman-Unti coordinates.
Abstract: Using Newman-Unti coordinates, we obtain the superpotential for the radiative part of the Lienard-Wiechert electromagnetic field generated by an arbitrarily moving charge in the Minkowski space.
TL;DR: In this paper, it is shown that the phase-equivalent potentials obtained by the application of supersymmetric quantum mechanics are not off-shell equivalent, and a case study is presented in support of this.
Abstract: Methods of supersymmetric quantum mechanics (SUSYQM) are used to derive relations between phase functions which occur in the context of the variable-phase approach to potential scattering. It is shown that the phase-equivalent potentials obtained by the application of SUSYQM are not off-shell equivalent. A case study is presented in support of this.
TL;DR: A nine-parameter «quasiflat» direction is identified which generates δρ/ρ through chaotic inflation and which leads to an AflReck-Dine valley (flat direction) where primordial baryogenesis occurs.
Abstract: We propose a mechanism by which density perturbations δρ/ρ-10 -4 and a baryon asymmetry n B /s ∼10 -10 can naturally be generated in any realistic supersymmetric theory. By «naturally» we mean that the coefficient λ in the usual toy-model inflationary potential V=λO 4 is related to the superpotential Yukama coupling λ e which generates the electron mass. We identify a nine-parameter «quasiflat» direction which generates δρ/ρ through chaotic inflation and which leads to an AflReck-Dine valley (flat direction) where primordial baryogenesis occurs
TL;DR: In this paper, a numerical renormalization group analysis of the feasibility of the radiative gauge symmetry breaking parametrized by the standard soft supersymmetry breaking terms is presented.
Abstract: We compute one loop radiative corrections to the physical neutralino masses in the MSSM considering the dominant top-stop contributions. We present a numerical renormalization group analysis of the feasibility of the radiative gauge symmetry breaking parametrized by the standard soft supersymmetry breaking terms. Although the above computed effects can be in principle large for extreme values of the Yukawa couplings, they do not in general exceed a few per cent for most of the parameter space. Therefore tree level constraints imposed on the gluino mass $m_{\tilde{g}}$ and on the superpotential parameter $\mu$ by LEP1 and CDF experiments, are not upset by the heavy top-stop sector.
TL;DR: In this article, a supersymmetric quantum mechanics model was developed that put a group structure on the creation and annihilation operators, and applied the scheme to a variety of quantum mechanical problems and work out a two-term energy recursion equation when the overall group structure is U(1, 1).
Abstract: We develop a recently proposed model within supersymmetric quantum mechanics that puts a group structure on the creation and annihilation operators. We apply the scheme to a variety of quantum mechanical problems and work out a two-term energy recursion equation when the overall group structure isU(1, 1).
TL;DR: Arai et al. as mentioned in this paper showed that the Wess-Zumino supersymmetric quantum mechanical model has infinitely many bosonic zero-energy ground states and no fermionic zero energy ground states.
Abstract: It is known that the N=2 Wess–Zumino supersymmetric quantum mechanical model with the superpotential V(z)=λeαz(λ ∈ C\{0},α≥0) has infinitely many bosonic zero‐energy ground states and no fermionic zero‐energy ground states [A. Arai, J. Math. Phys. 30, 1164 (1989)]. In this article, these results are extended to a more general model. The main results include the following: (1) identification of the spectra of the Hamiltonian H of the model; (2) non‐Fredholmness of a supercharge of the model, which is a Dirac‐type operator; (3) existence of infinitely many bosonic zero‐energy states of H; (4) nonexistence of fermionic zero‐energy states of H.
TL;DR: In this article, a topological Landau-Ginzburg model with superpotential W(X)=X^{-1) was studied and the role of gravitational descendants in this theory was examined.
Abstract: We study a topological Landau-Ginzburg model with superpotential W(X)=X^{-1}. This is argued to be equivalent to c=1 string theory compactified at the self-dual radius. We compute the tree-level correlation function of N tachyons in this theory and show their agreement with matrix-model results. We also discuss the nature of contact terms, the perturbed superpotential and the flow of operators in the small phase space. The role of gravitational descendants in this theory is examined, and the tachyon two-point function in genus 1 is obtained using a conjectured modification of the gravitational recursion relations.
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TL;DR: In this article, it was shown that the phase of one of the superpotential parameters does not contribute to any CPV in the MSSM and so is not constrained by \dn.
Abstract: It is well known that if phases and masses in the Minimal Supersymmetric Standard Model (MSSM) are allowed to have general values, the resulting neutron EDM ($d_n$) exceeds the experimental upper limit by about $10^3$. We assume that the needed suppression is not due to a fine-tuning of phases or masses, and ask what natural size of $CP$ violation (CPV) results. We show that (1) the phase of one of the superpotential parameters, $\mu$, does not contribute to any CPV in the MSSM and so is not constrained by \dn; (2) the MSSM contribution to $d_n$ is tiny, just coming from the CKM phase; (3) the phases in the MSSM cannot be used to generate a baryon asymmetry at the weak scale, given our assumptions; and (4) in non-minimal SUSY models, an effective phase can enter at one loop giving $d_n \sim 10^{-26}$\ecm, $d_e \sim 10^{-27}$\ecm, and allowing a baryon asymmetry to be generated at the weak scale, without fine-tunings. Our results could be evaded by a SUSY breaking mechanism which produced phases for the SUSY breaking parameters that somehow were naturally of order $10^{-3}$.
01 Jan 1993
TL;DR: Arai et al. as mentioned in this paper showed that the Wess-Zumino supersymmetric quantum mechanical model has infinitely many bosonic zero-energy ground states and no fermionic zero energy ground states.
Abstract: It is known that the N=2 Wess–Zumino supersymmetric quantum mechanical model with the superpotential V(z)=λeαz(λ ∈ C\{0},α≥0) has infinitely many bosonic zero‐energy ground states and no fermionic zero‐energy ground states [A. Arai, J. Math. Phys. 30, 1164 (1989)]. In this article, these results are extended to a more general model. The main results include the following: (1) identification of the spectra of the Hamiltonian H of the model; (2) non‐Fredholmness of a supercharge of the model, which is a Dirac‐type operator; (3) existence of infinitely many bosonic zero‐energy states of H; (4) nonexistence of fermionic zero‐energy states of H.
TL;DR: In this article, a comprehensive scheme of quantum deformation is presented and applied to supersymmetric quantum mechanics, and the connection with a recently proposed model and explore a new mode of quantum DEformation is explored.
TL;DR: In this paper, the exact S-matrices and the Casimir energy (a c-function) are determined along the entire renormalization group trajectory, running from c=3 (asymptotically) in the UV to the N=2 minimal model values of the central charge in the IR.
Abstract: We find exactly solvable N=2-supersymmetric flows whose infrared fixed points are the N=2 minimal models. The exact S-matrices and the Casimir energy (a c-function) are determined along the entire renormalization group trajectory. The c-function runs from c=3 (asymptotically) in the UV to the N=2 minimal model values of the central charge in the IR, leading us to interpret these theories as the Landau-Ginzburg models with superpotential $X^{k+2}$. Consideration of the elliptic genus gives further support for this interpretation. We also find an integrable model in this hierarchy which has spontaneously-broken supersymmetry and superpotential $X$, and a series of integrable models with (0,2) supersymmetry. The flows exhibit interesting behavior in the UV, including a relation to the N=2 super sine-Gordon model. We speculate about the relation between the kinetic term and the cigar target-space metric.
TL;DR: In this paper, a formula for the kernel of the supersymmetric time evolution operator is found, which is similar to the Feynman-Kac formula used in the path integrals of quantum mechanics.
Abstract: By use of path integrals in N=2 supersymmetric quantum mechanics, a formula for the kernel of the supersymmetric time evolution operator is found. Structurally it is similar to the Feynman–Kac formula used in the path integrals of quantum mechanics. Crucial to the development of this formula is a generalization of the Wiener measure based upon the free supercharges rather than the free Hamiltonian.
TL;DR: In this article, the flat coordinates for a model of a topological conformal field theory corresponding to the 'twisted' version of an N=2 superconformal Landau-Ginzburg field theory with central charge c=3 are analyzed.
Abstract: The problem of determination of the flat coordinates for a model of a topological conformal field theory corresponding to the 'twisted' version of an N=2 superconformal Landau-Ginzburg field theory with central charge c=3 is analysed. The model is characterized by a Landau-Ginzburg superpotential of the form: W= 1/4 x4+ 1/4 y4. All possible relevant and marginal perturbations with their corresponding couplings (expressed as functions of the dimensionless flat-coordinate) are added to the above superpotential to give the perturbed topological field theory model. It is seen that the couplings can be completely determined (and hence also the dependence of the perturbations on the flat coordinate) by imposing the conditions of flatness on the space of couplings of the perturbed theory.
01 Jan 1993
TL;DR: In this paper, the energy-momentum complex as well as the superpotential associated with Moller's theory are derived and two different solutions, giving rise to the same metric, are obtained.
Abstract: MNler's tetrad theory of gravitation is examined with regard to the energymomentum complex. The energy-momentum complex as well as the superpotential associated with Moller's theory are derived. Mr field equations are solved in the case of spherical symmetry. Two different solutions, giving rise to the same metric, are obtained. The energy associated with one solution is found to be twice the energy associated with the other. Some suggestions to get out of this inconsistency are discussed at the end of the paper.