29,813 research outputs found
Some sharp inequalities involving Seiffert and other means and their concise proofs
In the paper, by establishing the monotonicity of some functions involving
the sine and cosine functions, the authors provide concise proofs of some known
inequalities and find some new sharp inequalities involving the Seiffert,
contra-harmonic, centroidal, arithmetic, geometric, harmonic, and root-square
means of two positive real numbers and with .Comment: 10 page
Geometric convexity of the generalized sine and the generalized hyperbolic sine
In the paper, the authors prove that the generalized sine function
and the generalized hyperbolic sine function
are geometrically concave and geometrically convex, respectively. Consequently,
the authors verify a conjecture posed in the paper "B. A. Bhayo and M.
Vuorinen, On generalized trigonometric functions with two parameters, J.
Approx. Theory 164 (2012), no.~10, 1415\nobreakdash--1426; Available online at
\url{http://dx.doi.org/10.1016/j.jat.2012.06.003}".Comment: 5 page
Fully open-flavor tetraquark states and with
We have studied the masses for fully open-flavor tetraquark states
and with quantum numbers
. We systematically construct all diquark-antiquark
interpolating currents and calculate the two-point correlation functions and
spectral densities in the framework of QCD sum rule method. Our calculations
show that the masses are about GeV for the
tetraquark states and GeV for the tetraquarks. The
masses of tetraquarks are below the thresholds of
and final states for the scalar and
axial-vector channels respectively. The tetraquark states
with lie below the and thresholds.
Such low masses for these possible tetraquark states indicate that they can
only decay via weak interaction and thus are very narrow and stable.Comment: 17 pages, 4 figure
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