33,168 research outputs found
CP Violation from a Higher Dimensional Model
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
Electron-phonon bound states in graphene in a perpendicular magnetic field
The spectrum of electron-phonon complexes in a monolayer graphene is
investigated in the presence of a perpendicular quantizing magnetic field.
Despite the small electron-phonon coupling, usual perturbation theory is
inapplicable for calculation of the scattering amplitude near the threshold of
the optical phonon emission. Our findings beyond perturbation theory show that
the true spectrum near the phonon emission threshold is completely governed by
new branches, corresponding to bound states of an electron and an optical
phonon with a binding energy of the order of where
is the electron-phonon coupling and the phonon energy.Comment: To be published in Phys. Rev. Lett., 5 pages, 3 figures, 1 tabl
Comment on "The Phenomenology of a Nonstandard Higgs Boson in W_L W_L Scattering"
We show that in Composite Higgs models, the coupling of the Higgs resonance
to a pair of 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
Mass corrections in string theory and lattice field theory
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 is much bigger than
the scale of the UV completion (), 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
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
Inequalities for low-energy symmetric nuclear matter
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
Localization of Eigenfunctions in the Stadium Billiard
We present a systematic survey of scarring and symmetry effects in the
stadium billiard. The localization of individual eigenfunctions in Husimi phase
space is studied first, and it is demonstrated that on average there is more
localization than can be accounted for on the basis of random-matrix theory,
even after removal of bouncing-ball states and visible scars. A major point of
the paper is that symmetry considerations, including parity and time-reversal
symmetries, enter to influence the total amount of localization. The properties
of the local density of states spectrum are also investigated, as a function of
phase space location. Aside from the bouncing-ball region of phase space,
excess localization of the spectrum is found on short periodic orbits and along
certain symmetry-related lines; the origin of all these sources of localization
is discussed quantitatively and comparison is made with analytical predictions.
Scarring is observed to be present in all the energy ranges considered. In
light of these results the excess localization in individual eigenstates is
interpreted as being primarily due to symmetry effects; another source of
excess localization, scarring by multiple unstable periodic orbits, is smaller
by a factor of .Comment: 31 pages, including 10 figure
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