33,088 research outputs found

    Comment on "The Phenomenology of a Nonstandard Higgs Boson in W_L W_L Scattering"

    Get PDF
    We show that in Composite Higgs models, the coupling of the Higgs resonance to a pair of WW bosons is weaker than the corresponding Standard Model coupling, provided the Higgs arises from electroweak doublets only. This is partly due to the effects of the nonlinear realization of the chiral symmetries at the compositeness scale.Comment: 6 pages, BU-HEP 94-2

    CP Violation from a Higher Dimensional Model

    Get PDF
    It is shown that Randall-Sundrum model has the EDM term which violates the CP-symmetry. The comparison with the case of Kaluza-Klein theory is done. The chiral property, localization, anomaly phenomena are examined. We evaluate the bulk quantum effect using the method of the induced effective action. This is a new origin of the CP-violation.Comment: 15pages, Proc. of Int. Workshop on "Neutrino Masses and Mixings"(Dec.17-19,2006,Univ.of Shizuoka,Japan

    Charged and superconducting vortices in dense quark matter

    Full text link
    Quark matter at astrophysical densities may contain stable vortices due to the spontaneous breaking of hypercharge symmetry by kaon condensation. We argue that these vortices could be both charged and electrically superconducting. Current carrying loops (vortons) could be long lived and play a role in the magnetic and transport properties of this matter. We provide a scenario for vorton formation in protoneutron stars.Comment: Replaced with the published version. A typographical error in Eq. 2 is correcte

    Inequalities for low-energy symmetric nuclear matter

    Full text link
    Using effective field theory we prove inequalities for the correlations of two-nucleon operators in low-energy symmetric nuclear matter. For physical values of operator coefficients in the effective Lagrangian, the S = 1, I = 0 channel correlations must have the lowest energy and longest correlation length in the two-nucleon sector. This result is valid at nonzero density and temperature.Comment: 9 page

    Progress in Electroweak Baryogenesis

    Full text link
    Recent work on generating the excess of matter over antimatter in the early universe during the electroweak phase transition is reviewed.Comment: 50 pages (figures on request), uses harvmac (table of contents correct for "l" format), UCSD-93-2,BU-HEP-93-

    Mass corrections in string theory and lattice field theory

    Get PDF
    Kaluza-Klein compactifications of higher dimensional Yang-Mills theories contain a number of four dimensional scalars corresponding to the internal components of the gauge field. While at tree-level the scalar zero modes are massless, it is well known that quantum corrections make them massive. We compute these radiative corrections at 1-loop in an effective field theory framework, using the background field method and proper Schwinger-time regularization. In order to clarify the proper treatment of the sum over KK--modes in the effective field theory approach, we consider the same problem in two different UV completions of Yang-Mills: string theory and lattice field theory. In both cases, when the compactification radius RR is much bigger than the scale of the UV completion (Rα,aR \gg \sqrt{\alpha'},a), we recover a mass renormalization that is independent of the UV scale and agrees with the one derived in the effective field theory approach. These results support the idea that the value of the mass corrections is, in this regime, universal for any UV completion that respects locality and gauge invariance. The string analysis suggests that this property holds also at higher loops. The lattice analysis suggests that the mass of the adjoint scalars appearing in N=2,4\mathcal N=2,4 Super Yang-Mills is highly suppressed due to an interplay between the higher-dimensional gauge invariance and the degeneracy of bosonic and fermionic degrees of freedom.Comment: 27 page

    Low Energy Theorems For Nucleon-Nucleon Scattering

    Get PDF
    Low energy theorems are derived for the coefficients of the effective range expansion in s-wave nucleon-nucleon scattering valid to leading order in an expansion in which both mπm_\pi and 1/a1/a (where aa is the scattering length) are treated as small mass scales. Comparisons with phase shift data, however, reveal a pattern of gross violations of the theorems for all coefficients in both the 1S0^1S_0 and 3S1^3S_1 channels. Analogous theorems are developed for the energy dependence ϵ\epsilon parameter which describes 3S13D1^3S_1 - ^3D_1 mixing. These theorems are also violated. These failures strongly suggest that the physical value of mπm_\pi is too large for the chiral expansion to be valid in this context. Comparisons of mπm_\pi with phenomenological scales known to arise in the two-nucleon problem support this conjecture.Comment: 12 pages, 1 figure, 1 table; appendix added to discuss behavior in chiral limit; minor revisions including revised figure reference to recent work adde

    Renormalization of NN-Scattering with One Pion Exchange and Boundary Conditions

    Full text link
    A non perturbative renormalization scheme for Nucleon-Nucleon interaction based on boundary conditions at short distances is presented and applied to the One Pion Exchange Potential. It is free of off-shell ambiguities and ultraviolet divergences, provides finite results at any step of the calculation and allows to remove the short distance cut-off in a suitable way. Low energy constants and their non-perturbative evolution can directly be obtained from experimental threshold parameters in a completely unique and model independent way when the long range explicit pion effects are eliminated. This allows to compute scattering phase shifts which are, by construction consistent with the effective range expansion to a given order in the C.M. momentum pp. In the singlet 1S0^1S_0 and triplet 3S13D1^3S_1- ^3D_1 channels ultraviolet fixed points and limit cycles are obtained respectively for the threshold parameters. Data are described satisfactorily up to CM momenta of about pmπp \sim m_\pi.Comment: 22 pages, 10 figures, revte
    corecore