38,617 research outputs found
Mass spectra of Zc and Zb exotic states as hadron molecules
We construct charmonium-like and bottomonium-like molecular interpolating
currents with quantum numbers J(PC)=1(+-) in a systematic way, including both
color singlet-singlet and color octet-octet structures. Using these
interpolating currents, we calculate two-point correlation functions and
perform QCD sum rule analyses to obtain mass spectra of the charmonium-like and
bottomonium-like molecular states. Masses of the charmonium-like q_bar c c_bar
q molecular states for these various currents are extracted in the range
3.85-4.22 GeV, which are in good agreement with observed masses of the Zc
resonances. Our numerical results suggest a possible landscape of hadronic
molecule interpretations of the newly-observed Zc states. Mass spectra of the
bottomonium-like q_bar b b_bar q molecular states are similarly obtained in the
range 9.92-10.48 GeV, which support the interpretation of the Zb(10610) meson
as a molecular state within theoretical uncertainties. Possible decay channels
of these molecular states are also discussed.Comment: 15 pages, 3 figures, 2 tables, accepted by PR
Masses of the Bottom-Charm Hybrid States
QCD sum rules are used to study the mass spectrum of bottom-charm hybrid
systems. The correlation functions and the spectral densities are
calculated up to dimension six condensates at leading order of for
several quantum numbers. After performing the QCD sum rule analysis, we
predict the masses of the
bottom-charm hybrids. These mass predictions show a similar supermultiplet
structure as the bottomonium and charmonium hybrids. Using the QCD sum-rule
mass predictions we analyze the possible hadronic decay patterns of the , and hybrids including the open-flavour and
hidden-flavour mechanisms.Comment: 14 pages, 8 figures, 6 tables. Version to appear in Journal of
Physics
Exotic open-flavor , and , tetraquark states
We study the exotic , and
, systems by constructing the
corresponding tetraquark currents with and . After investigating
the two-point correlation functions and the spectral densities, we perform QCD
sum rule analysis and extract the masses of these open-flavor tetraquark
states. Our results indicate that the masses of both the scalar and axial
vector tetraquark states are about GeV for the
system and GeV for the system. For the
tetraquark states with and , their masses are
extracted to be around GeV. The masses for the scalar and axial vector
states are GeV and GeV, respectively. The
tetraquark states and lie below the
thresholds of and
respectively, but they can decay into plus a light meson. However, the
tetraquark states and lie below the
and thresholds,
suggesting dominantly weak decay mechanisms.Comment: 18 pages, 7 figures, 4 table
New Constructions of Zero-Correlation Zone Sequences
In this paper, we propose three classes of systematic approaches for
constructing zero correlation zone (ZCZ) sequence families. In most cases,
these approaches are capable of generating sequence families that achieve the
upper bounds on the family size () and the ZCZ width () for a given
sequence period ().
Our approaches can produce various binary and polyphase ZCZ families with
desired parameters and alphabet size. They also provide additional
tradeoffs amongst the above four system parameters and are less constrained by
the alphabet size. Furthermore, the constructed families have nested-like
property that can be either decomposed or combined to constitute smaller or
larger ZCZ sequence sets. We make detailed comparisons with related works and
present some extended properties. For each approach, we provide examples to
numerically illustrate the proposed construction procedure.Comment: 37 pages, submitted to IEEE Transactions on Information Theor
Doubly hidden-charm/bottom tetraquark states
We study the mass spectra for the and
tetraquark states by developing a moment sum rule method. Our results show that
the tetraquarks lie below the threshold of
. They are probably stable and very narrow. The masses
for the doubly hidden-charm states are higher than the
spontaneous dissociation thresholds of two charmonium mesons. We suggest to
search for such states in the and
channels.Comment: 8 pages, 2 figures. More references added. Conference proceedings for
6th International Conference on New Frontiers in Physics (ICNFP 2017), Crete,
Greece, 17-29 Aug, 201
Open-flavor charmed/bottom and tetraquark states
We provide comprehensive investigations for the mass spectrum of exotic
open-flavor charmed/bottom , , , tetraquark states with various spin-parity assignments
and in the framework of QCD sum rules. In the
diquark configuration, we construct the diquark-antidiquark interpolating
tetraquark currents using the color-antisymmetric scalar and axial-vector
diquark fields. The stable mass sum rules are established in reasonable
parameter working ranges, which are used to give reliable mass predictions for
these tetraquark states. We obtain the mass spectra for the open-flavor
charmed/bottom , , , tetraquark states with various spin-parity quantum numbers. In
addition, we suggest searching for exotic doubly-charged tetraquarks, such as
in future experiments at facilities
such as BESIII, BelleII, PANDA, LHCb and CMS, etc.Comment: 19 pages, 4 figures, 5 tables, accepted by Phys. Rev. D (in press
Interaction-induced first order correlation between spatially-separated 1D dipolar fermions
We calculate the ground-state properties of fermionic dipolar atoms or
molecules in a one-dimensional double-tube potential by using the Luttinger
liquid theory and the density matrix renormalization-group calculation. When
the external field is applied near a magic angle with respect to the
double-tube plane, the long-ranged dipolar interaction can generate a
spontaneous correlation between fermions in different tubes, even when the bare
intertube tunneling rate is negligibly small. Such interaction-induced
correlation strongly enhances the contrast of the interference fringes and
therefore can be easily observed in the standard time-of-flight experiment.Comment: Same as the published versio
- β¦