25,771 research outputs found
Measuring the ratio of and couplings through production
For a generic Higgs boson, measuring the relative sign and magnitude of its
couplings with the and bosons is essential in determining its origin.
Such a test is also indispensable for the 125-GeV Higgs boson. We propose that
the ratio of the and couplings can be directly
determined through the production, where denotes a generic Higgs
boson, owing to the tree-level interference effect. While this is impractical
at the LHC due to the limited sensitivity, it can be done at future
colliders, such as a 500-GeV ILC with the beam polarization
in the and
channels. The discovery potential of a
general ratio and the power to discriminate it from the SM value are studied in
detail. Combining the cross section of with the
measurements of coupling at the HL-LHC, one can further improve the
sensitivity of .Comment: 24 pages, 10 figures, 2 table
Production of Charmed Tetraquarks from and decays
Hadronic states composed of multi-quark flavors may exist in reality since
they are not prohibited by QCD. Compact four quark systems of color singlet are
classified as tetraquarks. To understand the properties of these states, more
theoretical and experimental efforts are needed. In this work, we study charmed
tetraquarks with three light flavors using flavor symmetry. States with
three different light quarks must be in a or a
multiplet. We investigate the production of charmed tetraquarks in and decays. Whether the states with
three light quarks belong to or can be determined by
studying various tetraquark and decays. We demonstrate that the decay
amplitudes for these decays can be parametrized by a few irreducible SU(3)
invariant amplitudes. We then derive relations for decay widths and CP
violating rate difference which can be examined experimentally. Although no
experimental measurement is available yet, they might be accessed at the
ongoing and forthcoming experiments like the LHCb and Belle-II. Measurements of
these observables can not only provide useful information for the study of
exotics spectroscopy but are also valuable information towards a better
understanding of some non-perturbative aspects of QCD.Comment: 14 page
Unification of Flavor SU(3) Analyses of Heavy Hadron Weak Decays
Analyses of heavy mesons and baryons hadronic charmless decays using the
flavor SU(3) symemtry can be formulated in two different forms. One is to
construct the SU(3) irreducible representation amplitude (IRA) by decomposing
effective Hamiltonian, and the other is to draw the topological diagrams (TDA).
In the flavor SU(3) limit, we study various ,
decays, and two-body nonleptonic decays of beauty/charm baryons, and
demonstrate that when all terms are included these two ways of analyzing the
decay amplitudes are completely equivalent. Furthermore we clarify some
confusions in drawing topological diagrams using different ways of describing
beauty/charm baryons.Comment: 36 pages, 6 figures, 16 table
A Model for Flavour Anomalies
We study the implications of flavour-changing neutral currents (FCNC's) in a
model with the electroweak gauge symmetry
for several anomalies appearing in induced decays in
LHCb data. In this model, and govern the left-handed
fermions in the first two generations and the third generation, respectively.
The physical and generate the transition at tree level,
leading to additional contributions to the semileptonic operators
. We find that although - mixing constrains the
parameters severely, the model can produce values of
in the range determined by Descotes-Genon {\it et. al.} in
Ref.~\cite{Descotes-Genon:2015uva} for this scenario to improve the global fit
of observables in decays induced by the transition. The
boson in this model also generates tree-level FCNC's for the leptonic
interactions that can accommodate the experimental central value of . In this case, the
model predicts sizeable branching ratios for , , and an enhancement of with respect to its SM
value.Comment: ReTex, 13 pages with two figures. A few typos corrected and several
references adde
Efficient Algorithms for Node Disjoint Subgraph Homeomorphism Determination
Recently, great efforts have been dedicated to researches on the management
of large scale graph based data such as WWW, social networks, biological
networks. In the study of graph based data management, node disjoint subgraph
homeomorphism relation between graphs is more suitable than (sub)graph
isomorphism in many cases, especially in those cases that node skipping and
node mismatching are allowed. However, no efficient node disjoint subgraph
homeomorphism determination (ndSHD) algorithms have been available. In this
paper, we propose two computationally efficient ndSHD algorithms based on state
spaces searching with backtracking, which employ many heuristics to prune the
search spaces. Experimental results on synthetic data sets show that the
proposed algorithms are efficient, require relative little time in most of the
testing cases, can scale to large or dense graphs, and can accommodate to more
complex fuzzy matching cases.Comment: 15 pages, 11 figures, submitted to DASFAA 200
Implications for and Modes from Observed Large
The unexpectedly large branching ratios for decays
could be of gluonic origin. We study the implications for and , where is the pseudoscalar glueball. In the
mechanism proposed by Fritzsch, large branching ratios are predicted for these
modes. The rate is barely within the experimental limit, and
, could be at the 0.1% and 1% level, respectively. Smaller but
less definite results are found for the mechanism of via the
gluon anomaly.Comment: 11 pages, revtex, no fig
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