8,796 research outputs found
The line shape of the radiative open-charm decay of Y(4140) and Y(3930)
In this work, we study the radiative open-charm decays and under the
assignments of and as molecular states for
Y(4140) and Y(3930) respectively. Based on our numerical result, we propose the
experimental measurement of the photon spectrum of and can further test the
molecular assignment for Y(4140) and Y(3930).Comment: 4 pages, 4 figures. More references and discussions added, typos
corrected. Accepted by Phys. Rev.
Low-lying charmed and charmed-strange baryon states
In this work, we systematically study the mass spectra and strong decays of
and charmed and charmed-strange baryons in the framework of
nonrelativistic constituent quark models. With the light quark cluster-heavy
quark picture, the masses are simply calculated by a potential model. The
strong decays are studied by the Eichten-Hill-Quigg decay formula. Masses and
decay properties of the well-established and states can be reproduced
by our method. can be assigned as a
or state. We prefer to interpret the
signal as a state although at present we cannot
thoroughly exclude the possibility that this is the same state as
. or could be
explained as the state or state,
respectively. We propose to measure the branching ratio of
in future,
which may disentangle the puzzle of this state. Our results support
as the first radial excited state of
with . The assignment of is analogous to
, \emph{i.e.}, a or
state. In addition, we predict some typical ratios
among partial decay widths, which are valuable for experimental search for
these missing charmed and charmed-strange baryons.Comment: 16 pages, 3 figures, 13 tables. Accepted by Eur. Phys. J.
Re-Study on the wave functions of states in LFQM and the radiative decays of
The Light-front quark model (LFQM) has been applied to calculate the
transition matrix elements of heavy hadron decays. However, it is noted that
using the traditional wave functions of the LFQM given in literature, the
theoretically determined decay constants of the obviously
contradict to the data. It implies that the wave functions must be modified.
Keeping the orthogonality among the states and fitting their decay
constants we obtain a series of the wave functions for . Based on
these wave functions and by analogy to the hydrogen atom, we suggest a modified
analytical form for the wave functions. By use of the modified
wave functions, the obtained decay constants are close to the experimental
data. Then we calculate the rates of radiative decays of . Our predictions are consistent with the experimental data on
decays within the theoretical and experimental
errors.Comment: 10 pages, 2 figures, 1 table. Typos corrected and more discussions
added. accepted for publication in Physical Review
Black hole solution and strong gravitational lensing in Eddington-inspired Born-Infeld gravity
A new theory of gravity called Eddington-inspired Born-Infeld (EiBI) gravity
was recently proposed by Ba\~{n}ados and Ferreira. This theory leads to some
exciting new features, such as free of cosmological singularities. In this
paper, we first obtain a charged EiBI black hole solution with a nonvanishing
cosmological constant when the electromagnetic field is included in. Then based
on it, we study the strong gravitational lensing by the asymptotic flat charged
EiBI black hole. The strong deflection limit coefficients and observables are
shown to closely depend on the additional coupling parameter in the
EiBI gravity. It is found that, compared with the corresponding charged black
hole in general relativity, the positive coupling parameter will
shrink the black hole horizon and photon sphere. Moreover, the coupling
parameter will decrease the angular position and relative magnitudes of the
relativistic images, while increase the angular separation, which may shine new
light on testing such gravity theory in near future by the astronomical
instruments.Comment: 14 pages, 7 figures, 1 table. Two issues on the deflection angle and
photon sphere were corrected and clarifie
Exploring open-charm decay mode of charmonium-like state
The newly observed exotic states are definitely not in the standard
structures, thus their existence composes a challenge to our
understanding on the fundamental principles of hadron physics. Therefore the
studies on their decay patterns which are determined by the non-perturbative
QCD will definitely shed light on the concerned physics. Generally the
four-quark states might be in a molecular state or tetraquark or their mixture.
In this work, we adopt the suggestion that is a charmonium-like
tetraquark made of a diquark and an anti-diquark. If it is true, its favorable
decay mode should be decaying into an open-charm baryon pair, since
such a transition occurs via strong interaction and is super-OZI-allowed. In
this work, we calculate the decay width of
in the framework of the quark pair creation (QPC) model. Our numerical results
on the partial width computed in the tetraquark configuration coincide with the
Belle data within a certain error tolerance.Comment: 8 pages, 4 figures, 1 table. Accepted by Eur. Phys. J.
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