Related papers: New Low-Energy Realization of the Superstring-Insp…
Supersymmetry and Grand Unification are the two most promising directions for physics beyond the Standard Model. They receive indirect experimental support from the apparent lightness of the Higgs boson, the values of the gauge couplings…
We present a class of minimal $U(1)_X$ models as a plausible solution to the $R_K$ anomaly that can also help reproduce the neutrino mixing pattern. The symmetries and the corresponding $X$-charges of the fields are determined in a…
In this paper, an electroweak model with massive neutrinos is proposed. The symmetry of the model is $SU(2)_L \times U(1)_Y \times U(1)_M$. Because of the mixing of neutrinos, the conversion of one lepton type to another is possible, but…
In the context of the minimal supersymmetric standard model, nonzero neutrino masses and mixing can be generated through renormalizable lepton number (and thus R-parity) violating operators. It is examined whether neutrino mass matrices…
We construct a supersymmetric standard model in the context of the $Z_{12-I}$ orbifold compactification of the heterotic string theory. The gauge group is $SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)^4\times[SO(10)\times U(1)^3]'$. We…
The doublet-triplet splitting problem is perhaps the most problematic aspect of supersymmetric grand unified theories. It can be argued that the most natural reason for the Higgs doublets to be light is that they are pseudo-Goldstone bosons…
Neutralinos with a large singlino component may appear in extended supersymmetric models with additional singlet Higgs fields. Since singlinos do not couple to (s)fermions and gauge bosons, the cross sections for the production of singlino…
The simplest unified extension of the Minimal Supersymmetric Standard Model with bi-linear R--Parity violation provides a predictive scheme for neutrino masses which can account for the observed atmospheric and solar neutrino anomalies in…
We study the phenomenological implications of effective supergravities based on string vacua with spontaneously broken N=1 supersymmetry by dilaton and moduli $F$-terms. We further require Minimal String Unification, namely that large…
A remarkable U(1) gauge extension of the supersymmetric standard model was proposed eight years ago. It is anomaly-free, has no mu term, and conserves baryon and lepton numbers automatically. The phenomenology of a specific version of this…
We study an extension of the Minimal Supersymmetric Standard Model with a gauge group $SU(2)_1\otimes SU(2)_2$ breaking to $SU(2)_L$. The extra wino has an enhanced gauge coupling to the SM-like Higgs boson and, if light, has a relevant…
We present the dark matter (DM) extension (by N) of the minimal supersymmetric standard model to give the recent trend of the high energy positron spectrum of the PAMELA/HEAT experiments. If the trend survives by future experiments, the…
We consider several low energy consequences arising from a class of supersymmetric models based on the gauge groups $SU(2)_L\times SU(2)_R \times U(1)_{B-L}$ and $SU(4)_C\times SU(2)_L \times SU(2)_R$ in which the gauge hierarchy and $\mu$…
The Next-to-Minimal Supersymmetric Standard Model (NMSSM) includes a Higgs iso-singlet superfield in addition to the two Higgs doublet superfields of the minimal extension. If the Higgs fields remain weakly coupled up to the GUT scale, as…
The supersymmetric flipped $SU(6)\times U(1)$ gauge symmetry can arise through compactification of the ten dimensional $E_8\times E_8$ superstring theory. We show how realistic phenomenology can emerge from this theory by supplementing it…
In a recent paper, we proposed the possibility that supersymmetry breaking is communicated dominantly via a U(1)' vector multiplet. We also required that the U(1)' plays a crucial role in solving the mu problem. We discuss here in detail…
Supersymmetric standard model with softly broken lepton symmetry provides a suitable framework to accommodate the solar and atmospheric neutrino anomalies. This model contains a natural explanation for large mixing and hierarchal masses…
The recent neutrino data converge towards a 3$\nu$ scheme with two large and one small mixing angles. Their implications for model-building are discussed. Some possible components of a flavor symmetry over quarks and leptons are singled…
The electroweak Higgs doublets are identified as components of a vector multiplet in a higher dimensional supersymmetric field theory. We construct a minimal model in 6D where the electroweak $SU(2) \otimes U(1)$ gauge group is extended to…
We show explicitly that supersymmetric $E_6$ Grand Unified Theory with a Higgs sector consisting of $\{27+\bar{27}+351'+\bar{351'}+78\}$ fields provides a realistic scenario for symmetry breaking and fermion mass generation. While gauge…