General massive multiplets in extended supersymmetry

We consider the extended Poincaré superalgebra in four dimensions with general central charge operators. We find the invariance of this algebra and the particle supermultiplets with their internal symmetry properties. Central charges obtained by dimensional reduction appear as a special case in this classification.     

Massive tensor multiplets in N = 1 supersymmetry

We derive the action for a massive tensor multiplet coupled to chiral and vector multiplets as it can appear in orientifold compactifications of type IIB string theory. We compute the potential of the theory and show its consistency with the corresponding Kaluza‐Klein reduction of N = 1 orientifold compactifications. The potential contains an explicit mass term for the scalar in the tensor multiplet which does not arise from eliminating an auxiliary field. A dual action with an additional massive vector multiplet is derived at the level of superfields.     

Search for supersymmetry in light nuclei

The supersymmetry assumption based on a system of valence interacting bosons and odd nucleons has been checked in the second half of the nuclear sd-shell. The dynamical supersymmetric hamiltonian restricted to the linear combination of chosen second-order Casimir invariants has been applied to energy levels of several nuclei organized in supermultiplets. The supersymmetry predictions for nine nuclei are in accord, to a good approximation, with experimental energy levels up to 4–7 MeV.     

Classification of the even-even nuclei in symplectic multiplets

A classification of the even-even nuclei withZ20,A-Z-20, in terms of the boson representation of thesp(4,R) algebra is proposed. All even-even nuclei whose valence nucleons occupy the same major nuclear shell are united in two symplectic multiplets and thus treated in a unified way. A qualitative analysis of the spectrum of the 2⁺ energy levels of the ground (quasiground) bands is carried out. This analysis shows the expediency of the classification scheme proposed—a periodic structure of the same type is observed in the different shells. This periodic structure is especially stable in the case of the heavy and superheavy nuclei.     

On the group-theoretical approach to extended conformal supersymmetry: Classification of multiplets

Physically important multiplets of indecomposable representations of the conformal superalgebra su(2, 2/N) are constructed and classified adapting results of Kac. Each multiplet exhausts, in particular, all superfields partially equivalent to a given one together with some invariant operators intertwining the superfields. Known examples of the linearized supergauge conformal theories are accommodated in this scheme.On leave of absence from the Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria.     

On the strong-CP problem in models with several Higgs multiplets and supersymmetry

We point out that the strong-CP problem becomes even more pressing in the context of weak models where CP violation originates in the Higgs sector. θ renormalization is numerically too large at the one-loop level and even divergent at the two-loop level. When supersymmetry (SUSY) is introduced, many more possible sources for CP violation open up. θ renormalization could stay finite in perturbation theory, however, we find that the one-loop result turns out to be too large by orders of magnitude unless SUSY fields like gauginos and higgsinos are highly degenerate in mass or SUSY breaking proceeds in a very special way, or a Peccei-Quinn symmetry holds leading to superlight axions.     

Two-nucleon transfer reactions uphold supersymmetry in atomic nuclei

The spectroscopic strengths of two-nucleon transfer reactions constitute a stringent test for two-nucleon correlations in the nuclear wave functions. A set of closed analytic expressions for ratios of spectroscopic factors is derived in the framework of nuclear supersymmetry. These ratios are parameter independent and provide a direct test of the wave functions. A comparison between the recently measured 198Hg(d-->,alpha)196Au reaction and the predictions from the nuclear quartet supersymmetry lends further support to the validity of supersymmetry in nuclear physics.     

U(6/4) supersymmetry in nuclei

We suggest that supergroups and superalgebras may be useful in classifying the spectra of certain even-even and even-odd nuclei. We show, in particular, that properties of many states in several nuclei, including excitation energies, electromagnetic transition rates and transfer reaction intensities, can be described by a U(6/4) supersymmetry. Our analysis provides the first evidence for the occurrence of supersymmetry in nature.     

Systematics of ground state multiplets of atomic nuclei in the delta-interaction approach

Pairing forces between nucleons in an atomic nucleus strongly influence its structure. One of the manifestations of pair interaction is the ground state multiplet (GSM) formation in the spectrum of low-lying excited states of even–even nuclei. The value of GSM splitting is determined by the value of pair interaction of nucleons; for each isotope, it can be estimated on the basis of experimental nuclear masses. The quality of this estimate is characterized by the degree of reproduction of GSM levels in the nucleus. The GSM systematics in even–even nuclei with a pair of identical nucleons in addition to the filled nuclear core is considered on the basis of delta interaction.     

A study of17N levels andT=3/2 multiplets in mass 17 nuclei

Ten states of¹⁷N have been excited via the¹⁸O(d,³He)¹⁷N reaction atE _itd=52 MeV. Thel-transfer values are presented for eight of these states. Based on the subsequent spin and parity assignments severalT=3/2 isobaric multiplets are proposed.     

Two-proton multiplets in Po

The ²⁰⁹Bi(α,t)²¹⁰Po reaction at 45 MeV has been used to study ²¹⁰Po. Many new levels have been observed and proton configurations are suggested for the lowest three multiplets.     

Massive vector multiplets in supergravity

Starting from a vector multiplet we construct general lagrangians using the tensor calculus. After a Weyl rescaling and other field redefinitions we find lagrangians for the massive spin $\text{(1,}\text{1}\text{2}\text{,}\text{1}\text{2}\text{, 0)}$ model coupled to supergravity. Among the class of lagrangians which we consider we find no supersymmetry breaking.     

Quark multiplets and their interactions

We investigate the potentials between static quark clusters in various SU(3)-representations below and above the deconfinement phase transition. In the confinement regime we are able to resolve in addition to the triplet-antitriplet system the triplet-sextet, the sextet-antisextet, and the octet-octet interactions at small distances. We give an explanation of the general laws for the interaction of quark clusters which have been found earlier. In the deconfinement regime we study multiplet-multiplet systems up to decuplets with high resolution. The energies at zero and infinite distance are determined by the Casimir operators.     

N=3 supersymmetry multiplets with vanishing trace anomaly: Building blocks of the N>3 supergravities

N?3 supergravity theories with vanishing one-loop trace anomaly may be constructed fron three basic N=3 multiplets, one of which contains an antisymmetric tensor gauge field. As an example we construct the N=4 theory and discuss its relationship to ten-dimensional supergravity.     

Temperature and supersymmetry

We study equal-time correlation functions at finite temperature in field theories with global supersymmetry. Global supersymmetry is found to be broken at finite temperature; the ground state is not supersymmetric but no Goldstone fermion appears. The temperature dependence of the mass spectrum in the one-loop approximation and leading order in temperature is investigated in several models. In the models that we consider with spontaneous supersymmetry breaking we find that the Goldstone fermion remains massless at the one-loop level. Ward identities describing the supersymmetry of the underlying theory are checked at the one-loop level. We also discuss the situation in supergravity.