6,878 research outputs found
Dispersion Relations Explaining OPERA Data From Deformed Lorentz Transformation
OPERA collaboration has reported evidence of superluminal phenomenon for
neutrinos. One of the possible ways to explain the superluminality is to have
Lorentz symmetry violated. It has been shown that dispersion relations put
forwards has the problem of physics laws vary in different inertial frames
leading to conflicting results on Cherenkov-like radiation, pion decay and high
energy neutrino cosmic ray. For theories with deformed Lorentz symmetry, by
modifying conservation laws corresponding to energy and momentum in the usual
Lorentz invariant theory, it is possible to have superluminal effect and at the
same time avoid to have conflicts encountered in Lorentz violating theories. We
study dispersion relations from deformed Lorentz symmetry. We find that it is
possible to have dispersion relations which can be consistent with data on
neutrinos. We show that once the superluminality as a function of
energy is known the corresponding dispersion relation in the deformed Lorentz
symmetry can be determined.Comment: 8 pages, 2 figures. Several typos corrected and some references adde
Search for a heavy dark photon at future colliders
A coupling of a dark photon from a with the standard model
(SM) particles can be generated through kinetic mixing represented by a
parameter . A non-zero also induces a mixing between
and if dark photon mass is not zero. This mixing can be large when
is close to even if the parameter is small. Many
efforts have been made to constrain the parameter for a low dark
photon mass compared with the boson mass . We study the
search for dark photon in for a
dark photon mass as large as kinematically allowed at future
colliders. For large , care should be taken to properly treat possible
large mixing between and . We obtain sensitivities to the parameter
for a wide range of dark photon mass at planed colliders,
such as Circular Electron Positron Collider (CEPC), International Linear
Collider (ILC) and Future Circular Collider (FCC-ee). For the dark photon mass
, the
exclusion limits on the mixing parameter are . The CEPC with and FCC-ee with
are more sensitive than the constraint from current
LHCb measurement once the dark photon mass . For , the sensitivity at
the FCC-ee with and is better
than that at the 13~TeV LHC with , while the sensitivity at
the CEPC with and can be even
better than that at 13~TeV LHC with for
.Comment: 21 pages, 5 figures, 2 table
Strong, Electroweak Interactions and Their Unification with Noncommutative Space-time
Quantum field theories based on noncommutative space-time (NCQFT) have been
extensively studied recently. However no NCQFT model, which can uniquely
describe the strong and electroweak interactions, has been constructed. This
prevents consistent and systematic study of noncommutative space-time. In this
work we construct a NCQFT model based on the trinification gauge group
. A unique feature of this model, that all
matter fields (fermions and Higgses) are assigned to (anti-)fundamental
representations of the factor SU(3) groups, allows us to construct a NCQFT
model for strong and electroweak interactions and their unification without
ambiguities. This model provides an example which allows consistent and
systematic study of noncommutative space-time phenomenology. We also comment on
some related issues regarding extensions to and models.Comment: 12 pages, Revtex, no figures. Version to be published in ERJ
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