A Gauge Mediation Model of Dynamical Supersymmetry Breaking without Color Instability

We construct a gauge mediation model of dynamical supersymmetry breaking (DSB) based on a vector-like gauge theory, in which there is a unique color-preserving true vacuum. The DSB scale $\Lambda/4\pi$ turns out to be as high as $\Lambda/4\pi \simeq 10^{8-9} GeV$, since the transmission of the DSB effects to the standard model sector is completed through much higher loops. This model is perfectly natural and phenomenologically consistent. We also stress that the dangerous D-term problem for the messenger U(1)_m is automatically solved by a charge conjugation symmetry in the vector-like gauge theory.Comment: 11 pages, Late

Exact Event Rates of Lepton Flavor Violating Processes in Supersymmetric SU(5) Model

Event rates of various lepton flavor violating processes in the minimal supersymmetric SU(5) model are calculated, using exact formulas which include Yukawa vertices of lepton-slepton-Higgsino. We find subtlety in evaluating event rates due to partial cancellation between diagrams. This cancellation typically reduces the event rates significantly, and the size of the reduction strongly depends on superparticle mass spectrum.Comment: 11pages, 8 figures. Fig.5 where the mu-e conversion rates in nuclei was shown was incorrect due to an error in our numerical computation.It is replaced in this corrected version. All conclusions remain unchange

Limit on the Color-Triplet Higgs Mass in the Minimum Supersymmetric SU(5) Model

In the minimum supersymmetric SU(5) GUT, we derive the upper limit on the mass of the color-triplet Higgs multiplets as \mhc\leq 2.4\times 10^{16}~\GEV (90 \% C.L.) taking all possible corrections into account in a renormalization group analysis. If the above upper limit is compared with a limit on \mhc from the negative search for the proton decay; \mhc \geq 2.0\times 10^{16}~\GEV (in which effects of the larger top-quark mass are included), the minimum supersymmetric SU(5) GUT is severely constrained

Neutrino Oscillations in an SO(10) SUSY GUT with U(2)xU(1)nU(2)xU(1)^{n} Family Symmetry

In a previous paper we analyzed fermion masses (focusing on neutrino masses and mixing angles) in an SO(10) SUSY GUT with U(2)\timesU(1)^n family symmetry. The model is "natural" containing all operators in the Lagrangian consistent with the states and their charges. With minimal family symmetry breaking vevs the model is also predictive giving a unique solution to atmospheric (with maximal $\nu_\mu \to \nu_\tau$ mixing) and solar (with SMA MSW $\nu_e \to \nu_s$ mixing) neutrino oscillations. In this paper we analyze the case of general family breaking vevs. We now find several new solutions for three, four and five neutrinos. For three neutrinos we now obtain SMA MSW, LMA MSW or vacuum oscillation solutions for solar neutrinos. In all three cases the atmospheric data is described by maximal $\nu_\mu \to \nu_\tau$ mixing. In the four and five neutrino cases, in addition to fitting atmospheric and solar data as before, we are now able to fit LSND data. All this is obtained with the additional parameters coming from the family symmetry breaking vevs; providing only minor changes in the charged fermion fits

Lepton Flavour Violation In Supersymmetric Models with Trilinear R-parity Violation

Supersymmetry with R-parity violation (RPV) provides an interesting framework for naturally accommodating small neutrino masses. Within this framework, we discuss the lepton-flavour violating (LFV) processes mu -> e gamma, mu -> eee, and mu -> e conversion in nuclei. We make a detailed study of the observables related to LFV in different RPV models, and compare them to the expectations of R-conserving supersymmetry with heavy right-handed neutrinos. We show that the predictions are vastly different and uniquely characterise each model, thus providing a powerful framework for experimentally distinguishing between different theories of LFV. Besides the obvious possibility of amplified tree-level generation of mu -> eee and mu -> e conversion in nuclei, we find that even in the case where these processes arise at the one-loop level, their rates are comparable to that of mu -> e gamma, in clear contrast to the predictions of R-conserving models. We conclude that in order to distinguish between the different models, such a combined study of all the LFV processes is necessary, and that measuring P-odd asymmetries in polarised mu -> eee can play a decisive role. We also comment on the intriguing possibility of RPV models yielding a large T-odd asymmetry in the decay of polarised mu -> eee

A Solution for Little Hierarchy Problem and b --> s gamma

We show that all the parameters which destabilize the weak scale can be taken around the weak scale in the MSSM without conflicting with the SM Higgs mass bound set by LEP experiment. The essential point is that if the lightest CP-even Higgs h in the MSSM has only a small coupling to Z boson, g_{ZZh}, LEP cannot generate the Higgs sufficiently. In the scenario, the SM Higgs mass bound constrains the mass of the heaviest CP-even Higgs H which has the SM like g_{ZZH} coupling. However, it is easier to make the heaviest Higgs heavy by the effect of off-diagonal elements of the mass matrix of the CP-even Higgs because the larger eigenvalue of 2 times 2 matrix becomes larger by introducing off-diagonal elements. Thus, the smaller stop masses can be consistent with the LEP constraints. Moreover, the two excesses observed at LEP Higgs search can naturally be explained as the signals of the MSSM Higgs h and H in this scenario. One of the most interesting results in the scenario is that all the Higgs in the MSSM have the weak scale masses. For example, the charged Higgs mass should be around 130 GeV. This looks inconsistent with the lower bound obtained by the b --> s gamma process as m_{H^\pm}>350GeV. However, we show that the amplitude induced by the charged Higgs can naturally be compensated by that of the chargino if we take the mass parameters by which the little hierarchy problem can be solved. The point is that the both amplitudes have the same order of magnitudes when all the fields in the both loops have the same order of masses.Comment: 14 pages, 5 figures, input parameter slightly changed, figures replaced, references correcte

Phenomenological implications of neutrinos in extra dimensions

Standard Model singlet neutrinos propagating in extra dimensions induce small Dirac neutrino masses. While it seems rather unlikely that their Kaluza-Klein excitations directly participate in the observed neutrino oscillations, their virtual exchange may lead to detectable signatures in future neutrino experiments and in rare charged lepton processes. We show how these effects can be described by specific dimension-six effective operators and discuss their experimental signals

Peningkatan Pemahaman Tentang Pentingnya Mengenali HIV AIDS Sejak Dini di SMP N 8 Kediri

Kejadian HIV/AIDS merupakan permasalahan global yang hingga saat ini masih belum terselesaikan, termasuk di Indonesia. Kasus tertinggi terjadi pada kelompok umur 20-49 tahun yang mengindikasikan pada usia remaja (15-25 tahun) mereka sudah mengidap HIV. Penyebab tingginya kejadian HIV/AIDS pada remaja dipengaruhi banyak hal diantaranya kurangnya pengetahuan mereka tentang HIV/AIDS. Laporan ini bertujuan untuk mengetahui pengaruh penyuluhan terhadap pengetahuan dan sikap siswa siswi SMPN 8 Kediri. Laporan ini menggunakan metode presentasi dan diskusi tanya jawab. Hasil penyuluhan menunjukkan siswa maupun siswi yang setelah diberikan penyuluhan menjadi lebih memahami bahayanya HIV/AIDS karena beberapa faktor. Selain itu, antusias mereka dalam mencari informasi lebih dalam mengenai HIV/AIDS juga sangat baik setelah diberikan penyuluhan