Complete gluon bremsstrahlung corrections to the process b -> s l+ l-

In a recent paper, we presented the calculation of the order (alpha_s) virtual corrections to b->s l+ l- and of those bremsstrahlung terms which are needed to cancel the infrared divergences. In the present paper we work out the remaining order(alpha_s) bremsstrahlung corrections to b->s l+ l- which do not suffer from infrared and collinear singularities. These new contributions turn out to be small numerically. In addition, we also investigate the impact of the definition of the charm quark mass on the numerical results.Comment: 20 pages including 11 postscript figure

Higgs boson masses in supersymmetric theories

The Higgs boson mass problem is considered in the next to minimal supersymmetric standard model. The Higgs potential and the renormalization group equations for the gauge, Yukawa and scalar coupling constants are analyzed. The restrictions for the Higgs boson masses are found for the cases of presence and absence of spontaneous CP- violation

Tolerance to freezing stress in Cicer accessions under controlled and field conditions

Freezing tolerance was determined in 5 annual wild Cicer and 225 Cicer arietinum L. accessions, grown both in field and controlled conditions. In controlled conditions, the temperature was decreased 5°C daily to achieve -20°C. Field trial was conducted at Urmia, Iran. In general, 'kabuli' chickpeas were more susceptible to freezing stress than 'desi' chickpeas. Some 'kabuli' types such as FLIP 93-261C and x03TH21 which presented high freezing tolerance during early seedling stage, withstood -15.6°Cwithout snow cover. Based on severity score data, the highest freezing tolerance sources were all accessions of Cicer echinospermum and Cicer reticulatum and 15 lines from C. arietinum germplasm. The results obtained in controlled conditions were approximately confirmed in the field conditions. The most resistant genotypes to freezing stress were wild accessions of ILWC 81, ILWC 106, ILWC 139, ILWC 181, ILWC 235, and cultivated lines, Sel 96 TH 11404, Sel 96 TH 11439, Sel 96 TH 11488, Sel 98 TH 11518, x03TH21 and FLIP 93-261C. Our results indicated the possibility of autumn sowing of chickpea in the high plateaus of Iran

On the Groundstate of Yang-Mills Quantum Mechanics

A systematic method to calculate the low energy spectrum of SU(2) Yang-Mills quantum mechanics with high precision is given and applied to obtain the energies of the groundstate and the first few excited states.Comment: 4 pages REVTEX twocolumn, no figures; important calculational mistake corrected which considerably changes the conclusions; references adde

Direct CP-asymmetry in Inclusive Rare B-decays in 2HDM

The direct CP-asymmetry in the inclusive $B \to X_d \gamma$ and $B \to X_d e^+ e^ -$ decays is investigated in the two-Higgs doublet extension of the Standard Model (2HDM). The investigation is performed in the lowest non-vanishing order of the perturbation theory using the existing restrictions on the 2HDM parameters space. It is shown that the direct CP-asymmetry in the $B \to X_d \gamma$ decay can deviate significantly from the Standard Model predictions. In the presence of only one source of CP-violation (the CKM matrix weak phase) $a_{CP}(B \to X_d \gamma)$ can have the sign opposite to that in the SM. The new source of CP-violation can make $|a_{CP}(B \to X_d \gamma)|$ arbitrary small (unlike the SM case) and hence unmeasurable. Quantitatively, the obtained results suffer from the uncertainty of the choice of renormalization scale. As for the $B \to X_d e^+ e^ -$ rate asymmetry, its renormalization scale dependence in the lowest non-vanishing order does not allow to conclude if this quantity is efficient for testing New Physics beyond the Standard Model.Comment: 16 pages including 2 figure

NNLL corrections to the angular distribution and to the forward-backward asymmetries in b -> X_s l+ l-

We present NNLL results for the double differential decay width dGamma(b -> X_s l+ l-)/(dsh dcos(theta)), where theta is the angle between the momenta of the b-quark and the l+, measured in the rest-frame of the lepton pair. From these results we also derive NNLL results for the lepton forward-backward asymmetries. Genuinely new calculations for the combined virtual- and gluon bremsstrahlung corrections associated with the operators O_7, O_9 and O_10 are necessary. We find that the NNLL corrections drastically reduce the renormalization scale dependence of the forward-backward asymmetries. In particular, sh_0, the position at which the forward-backward asymmetries vanish, is essentially free of uncertainties due to the renormalization scale at NNLL precision. We find sh_0(NNLL)=0.162 +/- 0.005, where the error is dominated by the uncertainty in (m_c/m_b). This is to be compared with sh_0(NLL)=0.144 +/- 0.020, where the error is dominated by uncertainties due to the choice of mu.Comment: 26 pages including 11 postscript figure