New limits on "odderon" amplitudes from analyticity constraints

In studies of high energy $pp$ and $\bar pp$ scattering, the odd (under crossing) forward scattering amplitude accounts for the difference between the $pp$ and $\bar pp$ cross sections. Typically, it is taken as $f_-=-\frac{p}{4\pi}Ds^{\alpha-1}e^{i\pi(1-\alpha)/2}$ ($\alpha\sim 0.5$), which has $\Delta\sigma, \Delta\rho\to0$ as $s\to\infty$, where $\rho$ is the ratio of the real to the imaginary portion of the forward scattering amplitude. However, the odd-signatured amplitude can have in principle a strikingly different behavior, ranging from having $\Delta\sigma\to$non-zero constant to having $\Delta\sigma \to \ln s/s_0$ as $s\to\infty$, the maximal behavior allowed by analyticity and the Froissart bound. We reanalyze high energy $pp$ and $\bar pp$ scattering data, using new analyticity constraints, in order to put new and precise limits on the magnitude of ``odderon'' amplitudes.Comment: 13 pages LaTex, 6 figure

Bounds on the lightest Higgs boson mass with three and four fermion generations

We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations SM(3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and four generations MSSM(3,4). Our analysis utilizes the SM(3,4) renormalization-group-improved one-loop effective potential of the Higgs boson to find the upper bounds on the Higgs mass in the MSSM(3,4) while the lower bounds in the SM(3,4) are derived from considerations of vacuum stability. All the bounds increase as the degenerate fourth generation mass increases, providing more room in theory space that respects the increasing experimental lower limit of the Higgs mass.Comment: 24 pages, 10 figures, Some additional discussion added. Final version to be published in International Journal of Modern Physics

Gauge/String-Gravity Duality and Froissart Bound

The gauge/string-gravity duality correspondence opened renewed hope and possibility to address some of the fundamental and non-perturbative QCD problems in particle physics, such as hadron spectrum and Regge behavior of the scattering amplitude at high energies. One of the most fundamental and long-standing problem is the high energy behavior of total cross-sections. According to a series of exhaustive tests by the COMPETE group, (1). total cross-sections have a universal Heisenberg behavior in energy corresponding to the maximal energy behavior allowed by the Froissart bound, i.e., $A + B ln^2 (s/s_0)$ with $B \sim 0.32 mb$ and $s_0 \sim 34.41 GeV^2$ for all reactions, and (2). the factorization relation among $\sigma_{pp, even}, \sigma_{\gamma p}, and \sigma_{\gamma \gamma}$ is well satisfied by experiments. I discuss the recent interesting application of the gauge/string-gravity duality of $AdS/CFT$ correspondence with a deformed background metric so as to break the conformal symmetry that can lead to the Heisenberg behavior of rising total cross-sections, and present some preliminary results on the high energy QCD from Planckian scattering in $AdS$ and black-hole production.Comment: 10 pages, Presented to the Coral Gables Conference 2003, Launching of BelleE\'poque in High Energy Physics and Cosmology, 17 - 21 December 2003, Fort Lauderdale, Florid

Neutrino Oscillations and Lepton Flavor Mixing

In view of the recent announcement on non-zero neutrino mass from Super-Kamiokande experiment, it would be very timely to investigate all the possible scenarios on masses and mixings of light neutrinos. Recently suggested mass matrix texture for the quark CKM mixing, which can be originated from the family permutation symmetry and its suitable breakings, is assumed for the neutrino mass matrix and determined by the four combinations of solar, atmospheric and LSND neutrino data and cosmological hot dark matter bound as input constraints. The charged-lepton mass matrix is assumed to be diagonal so that the neutrino mixing matrix can be identified directly as the lepton flavor mixing matrix and no CP invariance violation originates from the leptonic sector. The results favor hierarchical patterns for the neutrino masses, which follow from the case when either solar-atmospheric data or solar-HDM constraints are used.Comment: Latex, 9 page