We report on recent constraints on models with a flat ``universal'' extra dimension in which all Standard Model fields propagate in the bulk. A significantly improved constraint on the compactification scale is obtained from the extended set of electroweak precision observables accurately measured at LEP1 and LEP2. We find a lower bound of 1/R > 700 (800) GeV at the 99% (95%) confidence level. Comparison of this constraint with the relic density of Kaluza-Klein dark matter for the Minimal UED model points towards the necessity of including non-minimal boundary terms which motivates studying alternative Kaluza-Klein dark matter candidates. Results for the one-loop induced magnetic dipole moment for Kaluza-Klein neutrino dark matter are presented. This talk is based on Phys.Rev.D73:095002,2006 and hep-ph/0601161.
I review the physics capabilities of the machines proposed for the next generation of high-energy experimentation: in hadron physics, the LHC, and in electron physics, a $500$--$1500$ GeV $e^+e^-$ linear collider. Using for illustration two specific models of electroweak symmetry breaking, I show how the $pp$ and $e^+e^-$ techniques are expected to complement one another in the exploration of the next scale of physics. [invited lecture at the 22nd INS Symposium, Tokyo] (text only; complete paper with figures and tables available by anonymous ftp from preprint.slac.stanford.edu, in the directory pub/preprints/hep-ph/9408)
hep-ph/9801348A NOTE ON R-PARITY VIOLATION AND FERMION MASSESM.E. GOMEZ and K. TAMVAKIS´Division of Theoretical Physics,University of Ioannina, GR-45110, GreeceAbstractWe consider aclass ofsupersymmetric SU(3)×SU(2)×U(1) multihiggs models inwhichR-parity is violated through bilinear Higgs-lepton interactions. The required, due toR-parity violation, higgs-lepton rotations introduce an alternative way to generatethe phenomenologically desirable fermion mass matrix structures independently of theequality of Yukawas, possibly imposed by superstring or other unification.January 1998E-mails: mgomez@cc.uoi.gr, tamvakis@cc.uoi.gr
This paper has been withdrawn by the authors. This paper started with a wrong term describing elastic scattering. The correct form of the kinetic equations for the density matrix are derived e.g. in A. Dolgov, Yad. Fiz. 33 (1981) 1309; K. Enqvist, K. Kainulainen and J. Maalampi, Nucl. Phys. B 349 (1991) 754; G. Sigl and G. Raffelt, Nucl. Phys. B 406 (1993) 423. When using the correct form of the kinetic equations, the result is in good agreement with old results, A. Dolgov and S. Hansen, hep-ph/0009083.
In the paper nucl-ex/0010009 by The Jefferson Lab F_pi Collaboration the new results for the charged pion electromagnetic form factor are presented. The approach given in our paper hep-ph/9811318, "On a possible estimation of the constituent--quark parameters from Jefferson Lab experiments on the pion form factor" makes it possible to estimate the mass of constituent quark from such kind of experiment. Now this estimation gives M=0.21 GeV.
Withdrawn by arXiv administration because the text and equations were plagiarized from chapter 10 of the BaBar Physics Book this http URL See also hep-ph/0304045
We review the computation of the thermodynamic pressure of the entire minimal standard model to three loop order, performed in [A. Gynther, M. Vepsalainen, JHEP 0601, 060 (2006), [ hep-ph/0510375 ], JHEP 0603, 011 (2006), [ hep-ph/0512177 ]].
The Rb and Rc crises described by Kaoru Hagiwara in hep-ph/9512425 can be resolved by the T-quark mass value of 130 GeV and the alpha_s(M_Z) value of 0.106 of the D4-D5-E6 model described in hep-ph/9501252 and quant-ph/9503009.