6,910 research outputs found
The Scotogenic Models for Dirac Neutrino Masses
We construct the one-loop and two-loop scotogenic models for Dirac neutrino
mass generation in the context of extensions of standard model. It
is indicated that the total number of intermediate fermion singlets is uniquely
fixed by anomaly free condition and the new particles may have exotic
charges so that the direct SM Yukawa mass term
and the Majorana mass term
are naturally forbidden. After the spontaneous
breaking of symmetry, the discrete or symmetry
appears as the residual symmetry and give rise to the stability of
intermediated fields as DM candidate. Phenomenological aspects of lepton flavor
violation, DM, leptogenesis and LHC signatures are discussed.Comment: 18 pages, 16 figure
Influence of adjacent surface building on seismic response of shallow buried subway station structure
Taking the 6-storey frame structure as an example, using FLAC numerical simulation, the influence of the adjacent multi-storey buildings on the seismic response of the metro station structure (including the internal force and bias state of the station structure) is studied systematically, and the relationship between the influence and surrounding rock level change is analyzed. The research shows that the existence of surface buildings has obvious amplification effect on the internal force of the subway station and above. It mainly shows that the eccentricity of the vault of the subway station is increased, and the eccentricity of the arch waist is reduced. It has a great influence on the internal force and distribution range of the station structure. The worse the surrounding rock, the greater the internal force and influence range of the building to the station structure
Maximum gravitational mass inferred at about precision with multimessenger data of neutron stars
The maximal gravitational mass of nonrotating neutron stars ()
is one of the key parameters of compact objects and only loose bounds can be
set based on the first principle. With reliable measurements of the masses
and/or radii of the neutron stars, can be robustly inferred from
either the mass distribution of these objects or the reconstruction of the
equation of state (EoS) of the very dense matter. For the first time we take
the advantages of both two approaches to have a precise inference of (68.3% credibility), with the updated
neutron star mass measurement sample, the mass-tidal deformability data of
GW170817, the mass-radius data of PSR J0030+0451 and PSR J0740+6620, as well as
the theoretical information from the chiral effective theory (EFT) and
perturbative quantum chromodynamics (pQCD) at low and very high energy
densities, respectively. This narrow credible range is benefited from the
suppression of the high by the pQCD constraint and the exclusion
of the low by the mass function. Three different EoS
reconstruction methods are adopted separately, and the resulting
are found to be almost identical. This precisely evaluated
suggests that the EoS of neutron star matter is just moderately stiff and the
compact objects detected by the second generation
gravitational wave detectors are most likely the lightest black holes.Comment: 12 pages, 6 figure
Identifying the Riemann zeros by periodically driving a single qubit
The Riemann hypothesis, one of the most important open problems in pure
mathematics, implies the most profound secret of prime numbers. One of the most
interesting approaches to solve this hypothesis is to connect the problem with
the spectrum of the physical Hamiltonian of a quantum system. However, none of
the proposed quantum Hamiltonians have been experimentally feasible.Here, we
report the first experiment to identify the first non-trivial zeros of the
Riemann zeta function and the first two zeros of P\'olya's fake zeta function,
using a novel Floquet method, through properly designed periodically driving
functions. According to this method, the zeros of these functions are
characterized by the occurrence of crossings of quasi-energies when the
dynamics of the system are frozen. The experimentally obtained zeros are in
excellent agreement with their exact values. Our study provides the first
experimental realization of the Riemann zeros, which may provide new insights
into this fundamental mathematical problem.Comment: 5 pages, 7 figure
Burst expansion, distribution and diversification of MITEs in the silkworm genome
<p>Abstract</p> <p>Background</p> <p>Miniature inverted-repeat transposable elements (MITEs) are widespread in plants and animals. Although silkworm (<it>Bombyx mori</it>) has a large amount of and a variety of transposable elements, the genome-wide information of the silkworm MITEs is unknown.</p> <p>Results</p> <p>We used structure-based and homology approaches to search for MITEs in the silkworm genome. We identified 17 MITE families with a total of 5785 members, accounting for ~0.4% of the genome. 7 of 17 MITE families are completely novel based on the nucleotide composition of target site duplication (TSD) and/or terminal inverted repeats (TIR). Silkworm MITEs were widely and nonrandom distributed in the genome. One family named BmMITE-2 might experience a recent burst expansion. Network and diversity analyses for each family revealed different diversification patterns of the silkworm MITEs, reflecting the signatures of genome-shocks that silkworm experienced. Most silkworm MITEs preferentially inserted into or near genes and BmMITE-11 that encodes a germline-restricted small RNA might silence its the closest genes in silkworm ovary through a small RNA pathway.</p> <p>Conclusions</p> <p>Silkworm harbors 17 MITE families. The silkworm MITEs preferred to reside in or near genes and one MITE might be involved in gene silence. Our results emphasize the exceptional role of MITEs in transcriptional regulation of genes and have general implications to understand interaction between MITEs and their host genome.</p
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