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

CP asymmetry, branching ratios and isospin breaking effects of B -> K* gamma with the perturbative QCD approach

The radiative B -> K* gamma mode is caused by a penguin operator which is a quantum correction. Thus this mode may be useful in the search for physics beyond the standard model. In this paper, we compute the branching ratio, direct CP asymmetry, and isospin breaking effects within the Standard Model in the framework perturbative QCD, and discuss how new physics might show up in this decay.Comment: 20 pages, 44 figure

Combining exclusive semi-leptonic and hadronic B decays to measure |V_ub|

The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little theoretical uncertainty, provided the hadronic form factor for the B -> pi transition can be measured from some other B decay. In here, we suggest using the decay B -> pi J\psi. This is a color suppressed decay, and it cannot be properly described within the usual factorization approximation; we use instead a simple and very general phenomenological model for the b d J\psi vertex. In order to relate the hadronic form factors in the B -> pi J\psi and B -> pi + l + antineutrino_l decays, we use form factor relations that hold for heavy-to-light transitions at large recoil.Comment: Latex, 7 pages, no figure

Constraining the CKM Parameters using CP Violation in semi-leptonic B Decays

We discuss the usefulness of the CP violating semi-leptonic asymmetry a_{SL} not only as a signal of new physics, but also as a tool in constraining the CKM parameters. We show that this technique could yield useful results in the first years of running at the B factories. We present the analysis graphically in terms of M_{12}, the dispersive part of the B-Bbar mixing amplitude. This is complementary to the usual unitarity triangle representation and often allows a cleaner interpretation of the data.Comment: 15 pages REVTEX, 7 figure

Association between Insulin Like Growth Factor-1 (IGF-1) gene polymorphism and carcass traits in improved Nigerian indigenous chickens

The insulin-like growth factor-1 (IGF1) is a key regulator of muscle development and metabolism in birds and other vertebrate. Our objective was to determine the association between IGF1 gene polymorphism and carcass traits in FUNAAB Alpha chicken. Genomic DNA was extracted from the blood of 50 normal feathered birds. At 10 weeks, the birds were slaughtered for carcass traits. Specific primers for chicken IGF1 were used for amplification of a 622 base segment. The amplified gene products were digested with Hinf1 restriction enzyme and the digested fragments were genotyped. Allele frequencies were 52% and 48% for A and B, respectively. Genotype frequencies were 27%, 50% and 23% for AA, AB and BB genotypes, respectively. All carcass traits values and the IGF1 gene polymorphism observed were subjected to analysis of variance and the mean were separated using Duncan Multiple Range Test. The results showed that the occurrence of the polymorphism did not affect all the carcass traits but AB genotypes had the highest carcass traits values than the AA and BB genotypes. The conclusion of this study demonstrated that IGF-1 gene, to some extent, could be a candidate gene that affects carcass traits in Improved Nigerian indigenous chicken.Keywords: IGF-1, PCR-RFLP, indigenous chicke

Constraining New Physics with the CDF Measurement of CP Violation in B→ψKSB \to \psi K_S

Recently, the CDF collaboration has reported a measurement of the CP asymmetry in the $B\to\psi K_S$ decay: $a_{\psi K_S}=0.79^{+0.41}_{-0.44}$. We analyze the constraints that follow from this measurement on the size and the phase of contributions from new physics to B-\barB mixing. Defining the relative phase between the full $M_{12}$ amplitude and the Standard Model contribution to be $2\theta_d$, we find a new bound: \sin2\theta_d\gsim-0.6 (-0.87) at one sigma (95% CL). Further implications for the CP asymmetry in semileptonic B decays are discussed.Comment: 13 pages, harvmac, 3 figures; v2: a discussion of new physics effects on tree level decays added; references added; accepted for publication in Physical Review Letter

Unified approach to photo and electro-production of mesons with arbitrary spins

A new approach to identify the independent amplitudes along with their partial wave multipole expansions, for photo and electro-production is suggested,which is generally applicable to mesons with arbitrary spin-parity. These amplitudes facilitate direct identification of different resonance contributions.Comment: 11 page

CP violation in a multi-Higgs doublet model with flavor changing neutral current

We study CP violation in a multi-Higgs doublet model based on a $S_3 \times Z_3$ horizontal symmetry where CKM phase is not the principal source of CP violation. We consider two mechanisms for CP violation in this model: a) CP violation due to complex Yukawa couplings; and b) CP violation due to scalar-pseudoscalar Higgs boson mixings. Both mechanisms can explain the observed CP violation in the neutral Kaon system. $\epsilon'/\epsilon$ due to neutral Higgs boson exchange is small in both mechanisms, but charged Higgs boson con- tributions can be as large as $10^{-3}$ for a), and $10^{-4}$ for b). CP violation in the neutral B system is, however, quite different from the Minimal Standard Model. The neutron Electric Dipole Moment can be as large as the present ex- perimental bound, and can be used to constrain charged Higgs boson masses. The electron EDM is one order of magnitude below the experimental bound in case b) and smaller in case a).Comment: 22 pages, Revtex, OITS-52

Spontaneous CP violation in Supersymmetric theories

We study the minimal version of the supersymmetric standard model with spontaneous CP breaking. In this model, the KM matrix is real and contributions to $\varepsilon$ arise from box diagrams involving squarks. We analyze the region of the parameter space which corresponds to values for $\varepsilon$, $\varepsilon^\prime/\varepsilon$ and the neutron electric dipole moment (NEDM) in agreement with the experimental data. We show that the CP violating phases must be of \calo (10^{-2}) and the NEDM lies near its present experimental limit.Comment: 17 pages, 5 figures (no included), SCIPP-92/30, PHYZZX fil

CP--Violating Invariants in Supersymmetry

I study the weak basis CP-violating invariants in supersymmetric models, in particular those which cannot be expressed in terms of the Jarlskog--type invariants, and find basis--independent conditions for CP conservation. With an example of the K-anti-K mixing, I clarify what are the combinations of supersymmetric parameters which are constrained by experiment.Comment: matches the PRD versio