Browsing by Author "Rayyan, S."
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- Classical Implications of the Minimal Length Uncertainty RelationBenczik, S. Z.; Chang, Lay Nam; Minic, Djordje; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu (2002-09-12)We study the phenomenological implications of the classical limit of the "stringy" commutation relations [x_i,p_j]=i hbar[(1+beta p^2) delta_{ij} + beta' p_i p_j]. In particular, we investigate the "deformation" of Kepler's third law and apply our result to the rotation curves of gas and stars in spiral galaxies.
- NuTeV anomaly, lepton universality, and nonuniversal neutrino-gauge couplingsLoinaz, William; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2004-12)In previous studies we found that models with flavor-universal suppression of the neutrino-gauge couplings are compatible with NuTeV and Z-pole data. In this paper we expand our analysis to obtain constraints on flavor-dependent coupling suppression by including lepton universality data from W, tau, pi and K decays in fits to model parameters. We find that the data are consistent with a variety of patterns of coupling suppression. In particular, in scenarios in which the suppression arises from the mixing of light neutrinos with heavy gauge singlet states (neutrissimos), we find patterns of flavor-dependent coupling suppression which are also consistent with constraints from mu-->egamma.
- NuTeV anomaly, lepton universality, and nonuniversal neutrino-gauge couplingsLoinaz, William; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2004-12-01)
- Quark-lepton unification and lepton flavor nonconservation from a TeV-scale seesaw neutrino mass textureLoinaz, William; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2003-10-01)In a recent paper we pointed out that the mixing of the light neutrinos with heavy gauge singlet states could reconcile the Z-pole data from e(+)e(-) colliders and the nu(mu) ((nu) over bar (mu)) scattering data from the NuTeV experiment at Fermilab. We further noted that the mixing angle required to fit the data is much larger than what would be expected from the conventional seesaw mechanism. In this paper, we show how such mixings can be arranged by a judicious choice of the neutrino mass texture. We also argue that by invoking the unification of the Dirac mass matrix for the up-type quarks and the neutrinos, the mass of the heavy states can naturally be expected to lie in the few TeV range. The model is strongly constrained by the lepton flavor changing process mu-->egamma which requires lepton universality to be violated in the charged channel.
- Quark-lepton unification and lepton flavor nonconservation from a TeV-scale seesaw neutrino mass textureLoinaz, William; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2003-10-01)
- Short distance versus long distance physics: The classical limit of the minimal length uncertainty relationBenczik, S. Z.; Chang, Lay Nam; Minic, Djordje; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu (American Physical Society, 2002-07-15)
- Short distance versus long distance physics: The classical limit of the minimal length uncertainty relationBenczik, S. Z.; Chang, Lay Nam; Minic, Djordje; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu (American Physical Society, 2002-07-15)We continue our investigation of the phenomenological implications of the "deformed" commutation relations [(x) over cap (i),(p) over cap (j)]=i (h) over bar[(1+beta(p) over cap (2))delta(ij)+beta'(p) over cap (i)(p) over cap (j)]. These commutation relations are motivated by the fact that they lead to the minimal length uncertainty relation which appears in perturbative string theory. In this paper, we consider the effects of the deformation on the classical orbits of particles in a central force potential. Comparison with observation places severe constraints on the value of the minimum length.