ar X iv : h ep - p h / 97 07 44 5 v 1 2 3 Ju l 1 99 7 Fritzsch - Xing mass matrices , V td and CP Violating phase δ

ar X iv : h ep - p h / 97 07 53 6 v 1 3 1 Ju l 1 99 7 UAB – FT – 421 July 1997 Gravitinos from Gravitational Collapse

We reanalyse the limits on the gravitino mass m 3/2 in superlight gravitino scenarios derived from arguments on energy-loss during gravitational collapse. We conclude that the mass range 10 −7 eV ≤ m 3/2 ≤ 2.2 × 10 −6 eV is excluded by SN1987A data. In terms of the scale of supersymmetry breaking Λ, the range 70GeV ≤ Λ ≤ 300GeV is not allowed.

ar X iv : h ep - p h / 98 01 34 9 v 3 1 2 Ju n 19 98 hep - ph / 9801349 Alberta Thy - 02 - 98 January , 1998 revised

CP-violating signals in weak Ξ → πΛ decay require the knowledge of πΛ Sand P-wave scattering phases at m Ξ center-of-mass energy. We have calculated these phases in baryon chiral perturbation theory with the ground-state Σ in s and u channels and 3 2 + Σ(1385) in the u channel. We do not treat the baryons as heavy. We find δ S = 1.2 • and δ P = −1.7 • with the central value of the strong coupli...

ar X iv : h ep - t h / 97 07 23 0 v 1 2 8 Ju l 1 99 7 A Course on : “ Quantum Field

ar X iv : h ep - p h / 97 11 33 0 v 3 2 5 N ov 1 99 7 New Viewpoint to the Source of Weak CP Phase

In this work, we show that the weak CP phase may be interpreted as a geometric phase (or anholonomy). Thus, a simple relation of the geometric angle to the three rotation angles in the flavor space would completely determine the value of the weak phase δ. The obtained numerical value is reasonably consistent with that extracted from the data of ǫ in the K-system. PACS numbers: 11.30.Er New View...

ar X iv : h ep - t h / 97 07 19 5 v 1 2 3 Ju l 1 99 7 LMU - TPW - 97 / 19 The string scale and the Planck scale Rainer

A particle spectrum below the string scale in accordance with predictions from heterotic string theory yields a Planck mass mP l = (8πGN ) −1/2 which exceeds the string scale by a factor ≃ 61.9. A Planck mass mP l = 2.43× 1018 GeV then corresponds to a string scale ms = 3.9 × 1016 GeV. Such a low value for the string scale in turn implies that the relative strength of graviton and vector exchan...