3,925 research outputs found
Topological invariants for phase transition points of one-dimensional topological systems
We study topological properties of phase transition points of two
topologically non-trivial classes (D and DIII) in one dimension
by assigning a Berry phase defined on closed circles around the gap closing
points in the parameter space of momentum and a transition driving parameter.
While the topological property of the system is generally
characterized by a topological invariant, we identify that it
has a correspondence to the quantized Berry phase protected by the
particle-hole symmetry, and then give a proper definition of Berry phase to the
phase transition point. By applying our scheme to some specific models of class
D and DIII, we demonstrate that the topological phase transition can be well
characterized by the Berry phase of the transition point, which reflects the
change of Berry phases of topologically different phases across the phase
transition point.Comment: 6 pages, 5 figure
Winding numbers of phase transition points for one-dimensional topological systems
We study topological properties of phase transition points of one-dimensional
topological quantum phase transitions by assigning winding numbers defined on
closed circles around the gap closing points in the parameter space of momentum
and a transition driving parameter, which overcomes the problem of ill
definition of winding numbers on the transition points. By applying our scheme
to the extended Kitaev model and extended Su-Schrieffer-Heeger model, we
demonstrate that the topological phase transition can be well characterized by
winding numbers of transition points, which reflect the change of the winding
number of topologically different phases across the phase transition points.Comment: 5 pages, 5 figure
CP Violation and Extra Dimensions
It is shown that the new sources of CP violation can be generated in the
models with more than one extra dimensions. In the supersymmetric models on the
space-time , where the radius moduli have auxiliary vacuum
expectation values and the supersymmetry breaking is mediated by the
Kaluza-Klein states of gauge supermultiplets, we analyze the gaugino masses and
trilinear couplings for two scenarios and obtain that there exist relative CP
violating phases among the gaugino masses and trilinear couplings.Comment: Latex, 7 page
Electron Flavored Dark Matter
In this paper we investigate the phenomenology of the electron flavored Dirac
dark matter with two types of portal interactions. We analyze constraints from
the electron magnetic moment anomaly, LHC searches of singly charged scalar,
dark matter relic abundance as well as direct and indirect detections. Our
study shows that the available parameter space is quite constrained, but there
are parameter space that is compatible with the current data. We further show
that the DAMPE cosmic ray electron excess, which indicates cosmic ray excess at
around 1.5 TeV, can be interpreted as the annihilation of dark matter into
electron positron pairs in this model.Comment: 6 pages, 5 figure
Hunting for Heavy Majorana Neutrinos with Lepton Number Violating Signatures at LHC
The neutrinophilic two-Higgs-doublet model (2HDM) provides a natural way
to generate tiny neutrino mass from interactions with the new doublet scalar
() and singlet neutrinos of TeV scale. In this
paper, we perform detailed simulations for the lepton number violating (LNV)
signatures at LHC arising from cascade decays of the new scalars and neutrinos
with the mass order . Under constraints from lepton
flavor violating processes and direct collider searches, their decay properties
are explored and lead to three types of LNV signatures: , , and . We
find that the same-sign trilepton signature is quite
unique and is the most promising discovery channel at the high-luminosity LHC.
Our analysis also yields the C.L. exclusion limits in the plane of the
and masses at 13 (14) TeV LHC with an integrated luminosity of
100~(3000)/fb.Comment: 31 pages, 17 figures, 6 tables; v2: added a few refs and updated one
ref, without other change
Scales, Couplings Revisited and Low Energy Phenomenology in M-theory on
We revisit the eleven dimension Planck scale, the physical scale of the
eleventh dimension, the physical scale of Calabi-Yau manifold and coupling in
hidden sector in M-theory on . And we discuss the reasonable bound on
them. Considering F-term of dilaton and moduli SUSY breaking and choosing two
repersentative points which correspond to scalar quasi-massless scenario and
dilaton dominant SUSY breaking scenario respectively, we analyze experimental
constraints to the parameter space. The sparticle spectrum and some
phenomenological predictions are also given.Comment: 35 pages and 8 eps files. One error on fig1b is correcte
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