2,223 research outputs found
X(1812) in Quarkonia-Glueball-Hybrid Mixing Scheme
Recently a (X(1812)) state with a mass near the threshold of
and has been observed by the BES collaboration in decay. It has been suggested that it is a
state. If it is true, this state fits in a mixing scheme based on quarkonia,
glueball and hybrid (QGH) very nicely where five physical states are predicted.
Together with the known , , , and
states, X(1812) completes the five members in this family. Using known
experimental data on these particles we determine the ranges of the mixing
parameters and predict decay properties for X(1812). We also discuss some
features which may be able to distinguish between four-quark and hybrid mixing
schemes.Comment: 15 pages, 2 figures, 3 table
A preliminary study of photometric redshifts based on the Wide Field Survey Telescope
The Wide Field Survey Telescope (WFST) is a dedicated time-domain multi-band
(, , , , and ) photometric survey facility under construction.
In this paper, we present a preliminary study that assesses the quality of
photometric redshifts based on WFST by utilizing mock observations derived with
the galaxy catalog in the COSMOS/UltraVISTA field. We apply the template
fitting technique to estimate photometric redshifts by using the ZEBRA
photometric-redshift code and adopting a modified set of adaptive templates. We
evaluate the bias (median relative offset between the output photometric
redshifts and input redshifts), normalized median absolute deviation
() and outlier fraction () of photometric
redshifts in two typical WFST observational cases, the single 30-second
exposure observations (hereafter shallow mode) and co-added 50-minute exposure
observations (hereafter deep mode). We find bias\la0.006, \sigma_{\rm
NMAD}\la0.03, and f_{\rm outlier}\la5\% in the shallow mode and bias, , and -- in the deep mode, respectively, under various lunar phases.
Combining the WFST mock observational data with that from the upcoming CSST and
Euclid surveys, we demonstrate that the results can be
significantly improved, with and .Comment: 20 pages, 13 figures. Accepted for publication in Research in
Astronomy and Astrophysics (RAA
Exact Eigenfunctions of -Body system with Quadratic Pair Potential
We obtain all the exact eigenvalues and the corresponding eigenfunctions of
-body Bose and Fermi systems with Quadratic Pair Potentials in one
dimension. The originally existed first excited state level is missing in one
dimension, which results from the operation of symmetry or antisymmetry of
identical particles. In two and higher dimensions, we give all the eigenvalues
and the analytical ground state wave functions and the number of degeneracy.
Through the comparison with Avinash Khare's results, we have perfected his
results.Comment: 7 pages,1 figur
The single t-quark productions via the flavor-changing processes in the topcolor-assisted technicolor model at the hadron colliders
In the framework of topcolor-assisted technicolor(TC2) model, there exist
tree-level flavor-changing (FC) couplings which can result in the loop-level FC
coupling . Such coupling can contribute significant clues at the
forthcoming Large Hadron Collider (LHC) experiments. In this paper, based on
the TC2 model, we study some single t-quark production processes involving
coupling at the Tevatron and LHC: .
We calculate the cross sections of these processes. The results show that the
cross sections at the Tevatron are too small to observe the signal, but at the
LHC it can reach a few pb. With the high luminosity, the LHC has considerable
capability to find the single t-quark signal produced via some FC processes
involving coupling . On the other hand, these processes can also provide
some valuable information of the coupling with detailed study of the
processes and furthermore provide the reliable evidence to test the TC2 model.Comment: 15 pages, 10 figure
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Computational Design of a Tetrapericyclic Cycloaddition and the Nature of Potential Energy Surfaces with Multiple Bifurcations
An ambimodal transition state (TS) that leads to formation of four different pericyclic reaction products ([4 + 6]-, [2 + 8]-, [8 + 2]-, and [6 + 4]-cycloadducts) without any intervening minima has been designed and explored with DFT computations and quasiclassical molecular dynamics. Direct dynamics simulations propagated from the ambimodal TS show the evolution of trajectories to give the four cycloadducts. The topography of the PES is a key factor in product selectivity. A good correlation is observed between geometrical resemblance of the products to the ambimodal TS (measured by the RMSD) and the ratio of products formed in the dynamics simulationsWe are grateful to the National Science Foundation (CHE1764328 to K.N.H.) for financial support of this research and
for access to XSEDE and UCLA Hoffman 2 for computer time
and for this study. A.M.S. thanks the Madrid Government
(Comunidad de Madrid-Spain) under the Multiannual Agreement with Universidad Autónoma de Madrid in the line
Support to Young Researchers, in the context of the V PRICIT
(SI3-PJI-2021-00463) and “Ministerio de Educación Cultura y
Deporte” for funding (CAS18/00458
Berry Phase in Neutrino Oscillations
We study the Berry phase in neutrino oscillations for both Dirac and Majorana
neutrinos. In order to have a Berry phase, the neutrino oscillations must occur
in a varying medium, the neutrino-background interactions must depend on at
least two independent densities, and also there must be CP violation if the
neutrino interactions with matter are mediated only by the standard model W and
Z boson exchanges which implies that there must be at least three generations
of neutrinos. The CP violating Majorana phases do not play a role in generating
a Berry phase. We show that a natural way to satisfy the conditions for the
generation of a Berry phase is to have sterile neutrinos with active-sterile
neutrino mixing, in which case at least two active and one sterile neutrinos
are required. If there are additional new CP violating flavor changing
interactions, it is also possible to have a non-zero Berry phase with just two
generations.Comment: RevTex 16 pages, no figures, new discussions about sterile neutrino
added,typos corrected and errors in references correcte
Study on contributions of hadronic loops to decays of vector pseudoscalar mesons
In this work, we evaluate the contributions of the hadronic loops to the
amplitudes of where and denote light pseudoscalar and
vector mesons respectively. By fitting data of two well measured channels of
, we obtain the contribution from the pure OZI process to the
amplitude which is expressed by a phenomenological quantity
, and a parameter existing in the calculations
of the contribution of hadronic loops. In terms of and
, we calculate the branching ratios of other channels
and get results which are reasonably consistent with data. Our results show
that the contributions from the hadronic loops are of the same order of
magnitude as that from the OZI processes and the interference between the two
contributions are destructive. The picture can be applied to study other
channels such as PP or VV of decays of .Comment: 9 pages, 3 figures, 1 table. Some descriptions changed, more
references added and typos corrected. Published version in PR
Transport Measurements on Nano-engineered Two Dimensional Superconducting Wire Networks
Superconducting triangular Nb wire networks with high normal-state resistance
are fabricated by using a negative tone hydrogen silsesquioxane (HSQ) resist.
Robust magnetoresistance oscillations are observed up to high magnetic fields
and maintained at low temperatures, due to the eective reduction of wire
dimensions. Well-defined dips appear at integral and rational values (1/2, 1/3,
1/4) of the reduced flux f = Phi/Phi_0, which is the first observation in the
triangular wire networks. These results are well consistent with theoretical
calculations for the reduced critical temperature as a function of f.Comment: 4 pages, 3 figure
A new parametric equation of state and quark stars
It is still a matter of debate to understand the equation of state of cold
supra-nuclear matter in compact stars because of unknown on-perturbative strong
interaction between quarks. Nevertheless, it is speculated from an
astrophysical view point that quark clusters could form in cold quark matter
due to strong coupling at realistic baryon densities. Although it is hard to
calculate this conjectured matter from first principles, one can expect the
inter-cluster interaction to share some general features to nucleon-nucleon
interaction. We adopt a two-Gaussian component soft-core potential with these
general features and show that quark clusters can form stable simple cubic
crystal structure if we assume Gaussian form wave function. With this
parameterizing, Tolman-Oppenheimer-Volkoff equation is solved with reasonable
constrained parameter space to give mass-radius relation of crystalline solid
quark star. With baryon densities truncated at 2 times nuclear density at
surface and range of interaction fixed at 2fm we can reproduce similar
mass-radius relation to that obtained with bag model equations of state. The
maximum mass ranges from about 0.5 to 3 solar mass. Observed maximum pulsar
mass (about 2 solar mass) is then used to constrain parameters of this simple
interaction potential.Comment: 5 pages, 2 figure
Experimental realization of continuous-time quantum walks on directed graphs and their application in PageRank
PageRank is an algorithm used by Google Search to rank web pages in their search engine results. An important step for quantum networks is to quantize the classical protocol as quantum mechanics provides computational resources that can be used to outperform classical algorithms. In this paper, we experimentally realize continuous-time quantum walks for directed graphs with non-Hermitian adjacency matrices by using linear optical circuits and single photons. We find that the node classical centrality in a directed graph is correlated with the maximum node probability resulting from a continuous-time quantum walk and then demonstrate PageRank. Our work opens up an avenue of applications of quantum information in real-life tasks
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