2,180 research outputs found
Scalegenesis and fermionic dark matters in the flatland scenario
We propose an extension of the standard model with Majorana-type fermionic
dark matters based on the flatland scenario where all scalar coupling
constants, including scalar mass terms, vanish at the Planck scale, i.e. the
scalar potential is flat above the Planck scale. This scenario could be
compatible with the asymptotic safety paradigm for quantum gravity. We search
the parameter space so that the model reproduces the observed values such as
the Higgs mass, the electroweak vacuum and the relic abundance of dark matter.
We also investigate the spin-independent elastic cross section for the Majorana
fermions and a nucleon. It is shown that the Majorana fermions as dark matter
candidates could be tested by dark matter direct detection experiments such as
XENON, LUX and PandaX-II. We demonstrate that within the minimal setup
compatible with the flatland scenario at the Planck scale or asymptotically
safe quantum gravity, the extended model could have a strong predictability.Comment: 23 pages, 9 figures, Version published in EPJ
Perfect difference systems of sets and Jacobi sums
AbstractA perfect (v,{ki∣1≤i≤s},ρ) difference system of sets (DSS) is a collection of s disjoint ki-subsets Di, 1≤i≤s, of any finite abelian group G of order v such that every non-identity element of G appears exactly ρ times in the multiset {a−b∣a∈Di,b∈Dj,1≤i≠j≤s}. In this paper, we give a necessary and sufficient condition in terms of Jacobi sums for a collection {Di∣1≤i≤s} defined in a finite field Fq of order q=ef+1 to be a perfect (q,{ki∣1≤i≤s},ρ)-DSS, where each Di is a union of cyclotomic cosets of index e (and the zero 0∈Fq). Also, we give numerical results for the cases e=2,3, and 4
Neutrino emissions in all flavors up to the pre-bounce of massive stars and the possibility of their detections
This paper is a sequel to our previous one (Kato et al.2015), which
calculated the luminosities and spectra of electron-type anti-neutrinos
('s) from the progenitors of core-collapse supernovae. Expecting
that a capability to detect electron-type neutrinos ('s) will increase
dramatically with the emergence of liquid-argon detectors such as DUNE, we
broaden the scope in this study to include all-flavors of neutrinos emitted
from the pre-bounce phase. We pick up three progenitor models of an electron
capture supernova (ECSN) and iron-core collapse supernovae (FeCCSNe). We find
that the number luminosities reach and
at maximum for and ,
respectively. We also estimate the numbers of detection events at terrestrial
neutrino detectors including DUNE, taking flavor oscillations into account and
assuming the distance to the progenitors to be 200 pc. It is demonstrated that
's from the ECSN-progenitor will be undetected at almost all
detectors, whereas we will be able to observe 15900 's at DUNE
for the inverted mass hierarchy. From the FeCCSN-progenitors, the number of
events will be largest for JUNO, 200-900 's,
depending on the mass hierarchy whereas the number of events at DUNE is
2100 for the inverted mass hierarchy. These results imply that the
detection of 's is useful to distinguish FeCCSN- from
ECSN-progenitors, while 's will provide us with detailed information on
the collapse phase regardless of the type and mass of progenitor.Comment: 22 pages, 14 figures, 4 tables, accepted to Ap
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