6,290 research outputs found
ROLE OF VOLUNTARY SERVICE ACTIVITIES IN IMPROVING COLLEGE STUDENTS’ MENTAL HEALTH FROM THE PERSPECTIVE OF POSITIVE PSYCHOLOGY
Test of conformal gravity with astrophysical observations
Since it can describe the rotation curves of galaxies without dark matter and
can give rise to accelerated expansion, conformal gravity attracts much
attention recently. As a theory of modified gravity, it is important to test
conformal gravity with astrophysical observations. Here we constrain conformal
gravity with SNIa and Hubble parameter data and investigate whether it suffers
from an age problem with the age of APM~08279+5255. We find conformal gravity
can accommodate the age of APM~08279+5255 at 3 deviation, unlike most
of dark energy models which suffer from an age problem.Comment: 6 pages, 2 figure
The puzzle of anomalously large isospin violations in
The BES-III Collaboration recently report the observation of anomalously
large isospin violations in , where the in the invariant mass
spectrum appears to be much narrower ( 10 MeV) than the peak width
(50 MeV) measured in other processes. We show that a mechanism, named as
triangle singularity (TS), can produce a narrow enhancement between the charged
and neutral thresholds, i.e., . It can also
lead to different invariant mass spectra for
and , which can possibly explain the long-standing puzzle
about the need for two close states and in
and , respectively. The TS could be a key to our
understanding of the nature of and advance our knowledge
about the mixing between and .Comment: 4 pages and 7 eps figures; Journal-matched versio
Tip induced unconventional superconductivity on Weyl semimetal TaAs
Weyl fermion is a massless Dirac fermion with definite chirality, which has
been long pursued since 1929. Though it has not been observed as a fundamental
particle in nature, Weyl fermion can be realized as low-energy excitation
around Weyl point in Weyl semimetal, which possesses Weyl fermion cones in the
bulk and nontrivial Fermi arc states on the surface. As a firstly discovered
Weyl semimetal, TaAs crystal possesses 12 pairs of Weyl points in the momentum
space, which are topologically protected against small perturbations. Here, we
report for the first time the tip induced superconductivity on TaAs crystal by
point contact spectroscopy. A conductance plateau and sharp double dips are
observed in the point contact spectra, indicating p-wave like unconventional
superconductivity. Furthermore, the zero bias conductance peak in low
temperature regime is detected, suggesting potentially the existence of
Majorana zero modes. The experimentally observed tunneling spectra can be
interpreted with a novel mirror-symmetry protected topological superconductor
induced in TaAs, which can exhibit zero bias and double finite bias peaks, and
double conductance dips in the measurements. Our work can open a broad avenue
in search for new topological superconducting phases from topological Weyl
materials and trigger intensive investigations for pursuing Majorana fermions
Measurement of monocyte apoptosis, plasma IL-1β and PR3 activity as an approach to evaluate the immunological status in sepsis
Fourier-Jacobi models of Deligne-Lusztig characters and depth zero local descent for unitary groups
In this paper, we deduce explicit multiplicity formulas of the Fourier-Jacobi
model for Deligne-Lusztig characters of finite symplectic groups, unitary
groups, and general linear groups. We then apply these results to deduce the
explicit depth zero local descent (\`a la Soudry and Tanay) for -adic
unitary groups. The result is a concrete example in the context of non-tempered
Gan-Gross-Prasad program.Comment: 31 pages. Comments are welcom
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