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Dr
Kai Zhu
(高能所)
17/08/2019, 14:30
Session 3: Exotic hadrons and candidates
Leading parallel
X(3872) has been observed for more than 15 years ago, but its nature is still unclear. It is considered as an unconventional charmonium candidate. BESIII has collected about 12 fb^{-1} data at center of mass energies from 4.15 to 4.60 GeV. Using these data samples, the decay of X(3872) has been studied extensively, including pi0 chi_cJ, omega J/psi, pi pi J/psi, and gamma psi(1,2S). New...
Ms
Hikari Hirata
(Nagoya University)
17/08/2019, 14:55
Session 3: Exotic hadrons and candidates
Parallel
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. From February to July 2018, the machine has...
Prof.
Qian Wang
(South China Normal University)
17/08/2019, 15:15
Session 3: Exotic hadrons and candidates
Parallel
In the last decade, numerous states have been observed which contain a heavy quark-antiquark pair, but demonstrate properties at odds with a simple quarkonium assignement. Such states are conventionally denoted as exotic states and traditionally labelled by the letters X, Y and Z.
Due to the presence of the heavy quraks, properties of various exotic states can be related through the Heavy...
Xian-Wei Kang
(Beijing Normal University)
17/08/2019, 15:35
Session 3: Exotic hadrons and candidates
Parallel
We proposed a more general two-body scattering amplitude than the effective range expansion. Based on this new method, we found many new features on the exotic meson X(3872)
that is not realized previously. It can either be a bound state of $\bar DD^*$ or a virtual state, or a simultaneous virtual and bound state in the physical and unphysical Riemann Sheet. We also found it can correspond to...
Dr
Zhi-Yong Zhou
(Southeast University, China)
17/08/2019, 15:55
Session 3: Exotic hadrons and candidates
Parallel
By describing the $X(3872)$ using the extended Friedrichs scheme, in
which $D\bar D^*$ is the dominant component, we calculate the decay
rates of the $X(3872)$ to $\pi^0$ and a $P$-wave charmonium
$\chi_{cJ}$ state with $J=0,1$, or $2$, and its decays to
$J/\psi\pi^+\pi^-$ where $\pi^+\pi^-$ are assumed to be produced via
an intermediate $\rho$ state. The decay widths...
Zhiguo He
(Hamburg U.)
17/08/2019, 16:45
Session 3: Exotic hadrons and candidates
Leading parallel
Based on the hypothesis that the $X(3872)$ exotic hadron is a mixture of $\chi_{c1}(2P)$ and other states and that its prompt hadroproduction predominately proceeds via its $\chi_{c1}(2P)$ component, we calculate the prompt-X(3872) polarization at the CERN LHC through next-to-leading order in $\alpha_s$ within the factorization formalism of nonrelativistic QCD, including both the color-singlet...
Christian Fischer
(J)
17/08/2019, 17:10
Session 3: Exotic hadrons and candidates
Parallel
I review recent results on exotic hadrons such as glueballs and tetraquarks
obtained in the framework of functional Dyson-Schwinger and Bethe-Salpeter equations.
First results for quenched glueballs in this framework have been published in 2012; I
present an update of these results and discuss preliminary results in the unquenched case. For tetraquarks, based on our earlier results on the...
Dr
Hua-Xing Chen
(Beihang University)
17/08/2019, 17:30
Session 3: Exotic hadrons and candidates
Parallel
In this talk I shall review our QCD sum rule studies on exotic hadrons. In the past decade many charmonium-like states were observed experimentally, and various theoretical methods/models were applied to study them. The method of QCD sum rules is one of them, and has also been widely applied to study the mass spectra, production and decay properties of exotic hadrons.
Rafael Pavao
(IFIC)
17/08/2019, 17:50
Session 3: Exotic hadrons and candidates
Parallel
Many Ξc and Ξb resonances have been observed during past few of years. This works focus on studying several Ξc and Ξb dynamically generated states from meson-baryon interactions in coupled channels, using an extension of the local hidden gauge approach that we then unitarize using the Bethe-Salpeter equation. We are then able to identify several of our poles in the charm sector with some of...
Sean Dobbs
(Florida State University)
18/08/2019, 16:15
Session 3: Exotic hadrons and candidates
Leading parallel
Photoproduction of charmonium near threshold gives an excellent probe
for studying the gluonic structure of the nucleon. Of more recent
interest is the possibility of producing the $P_c^+$ pentaquark candidates
reported by LHCb in the s-channel reaction: $\gamma p -> P_c^+ \to p
J/\psi$. We report on the measurement of the total cross section
$\sigma(\gamma p \to p J/\psi)$ in 10 bins...
Dr
Meng-Lin Du
(HISKP, University of Bonn)
18/08/2019, 16:40
Session 3: Exotic hadrons and candidates
Parallel
The updated analysis of LHCb in the
$\Lambda_b^0\to J/\psi p K^-$ process with nine times data sample
in Run II presents three narrow pentaquark structures instead of
two in the previous analysis.
However, although the large data sample is available,
the quantum numbers of the three pentaquarks and the corresponding
anglular momentum distribution are still missing.
As these three...
Dr
Chu-Wen Xiao
(Central South University)
18/08/2019, 17:00
Session 3: Exotic hadrons and candidates
Parallel
The LHCb collaboration has reported recently three pentaquark states found in the $J/\psi N$ mass distribution. Based on the constraints of the heavy quark spin symmetry combined with the local hidden gauge symmetry, we investigate the ${\bar D}^{(*)}\Sigma_c^{(*)}$ interactions, together with $J/\psi N$ and other coupled channels, using a coupled channel approach. From the poles found in the...
Mr
Ming-Zhu Liu
(Beihang University)
18/08/2019, 17:20
Session 3: Exotic hadrons and candidates
Parallel
Since Pc(4380) and Pc(4450) were discovered by LHCb collaboration in 2015, the nature of two pentaquarks is still veiled. Recently, three pentaquark states, Pc(4312), Pc(4440),
Pc(4457) were discovered by LHCb with more precision, which inspired us to explore the nature of three pc states. In this talk, I will discuss the implementation of effective field theory to describe the three...
Yasuhiro Yamaguchi
(RIKEN)
18/08/2019, 17:40
Session 3: Exotic hadrons and candidates
Parallel
Exotic hadrons close to the hadron-hadron threshold have been one of the interesting topics in the hadron and nuclear physics. Especially, in the heavy quark sector, some of the quarkonium-like states called XYZ and the hidden-charm pentaquark Pc near the thresholds have been discussed as a hadronic molecule. The hadronic molecules is realized as a loosely bound state of a hadron composite...
Nicola Anne Skidmore
(Heidelberg)
20/08/2019, 14:00
Session 3: Exotic hadrons and candidates
Leading parallel
The quark model, proposed in the 1960s, predicts exotic hadrons beyond the conventional quark-antiquark mesons and three quark baryons. However, it was less than 15 years ago that exotic candidates were observed. Since then a number of exotic states have been discovered. LHCb has reported on tetraquark candidates such as the X(3872) as well as the discovery of pentaquark resonances in 2015....
Mr
Jielei Zhang
(Xinyang Normal University)
20/08/2019, 14:25
Session 3: Exotic hadrons and candidates
Parallel
The vector charmoniumlike (such as Y(4260), Y(4360), and Y(4660)) states are observed in exclusive processes in electron-positron collider, but not appear in the total hadronic cross section. Understanding of these vector charmoniumlike states is a challenge. BESIII has collected more than 13 fb^{-1} data samples at center of mass energies from 3.8 to 4.6 GeV, including 13 energy points with...
Ms
Renu Garg
(Panjab University)
20/08/2019, 14:45
Session 3: Exotic hadrons and candidates
Parallel
X(3872) and Y(4260) are famous for their exotic nature. We present
search for $B \to Y(4260) K$, $B \to X(3872) (\to \chi_{c1}\pi^0) K$ and
$B \to X(3915)(\to \chi_{c1} \pi^0) K$ at Belle based on the full data sample
accumulated by the Belle experiment at KEKB asymmetric energy $e^+ e^-$
collider. As no signal is found, upper limit on the product
branching fraction is provided.
We also...
Yun-Hua Chen
(University of Science and Technology Beijing)
20/08/2019, 15:05
Session 3: Exotic hadrons and candidates
Parallel
In this work, we try to gain insights into the structure of the $Y(4260)$ from the light-quark perspective.
We study the dipion invariant mass spectrum of the $e^+ e^-
\to Y(4260) \to J/\psi \pi^+\pi^-$ process and the ratio of the cross sections
${\sigma(e^+e^- \to J/\psi K^+ K^-)}/{\sigma(e^+e^- \to J/\psi \pi^+\pi^-)}$. In
particular, we consider the effects of different light-quark...
Zheng Zhao
(S)
20/08/2019, 15:25
Session 3: Exotic hadrons and candidates
Parallel
The mass of tetraquark states of all $q^2\bar q^2$ and $q\bar q c\bar c$ quark configurations is evaluated in a constituent quark model, where the Cornell potential is employed and all model parameters are predetermined by comparing the theoretical and experimental masses of light, charmed and bottom mesons.
The theoretical predictions of the charmed tetraquarks are compared with the observed...
Kim Maltman
(York University)
20/08/2019, 16:15
Session 3: Exotic hadrons and candidates
Leading parallel
We review recent lattice results from our collaboration (1) predicting strong-interaction-stable doubly heavy tetraquarks, and (2) investigating singly heavy exotic tetraquark channels where tetraquark candidates may be more easily accessible to experimental detection.
Prof.
Jean-Marc Richard
(Institut de Physique Nucleaire, Lyon)
20/08/2019, 16:40
Session 3: Exotic hadrons and candidates
Parallel
A detailed study is presented of the flavor-exotic isoscalar
$T_{bb}^-\equiv b b \bar u \bar d$ tetraquark. with spin and parity $J^P=1^+$.
In realistic quark models, with a careful treatment of the 4-body problem, the $T_{bb}^-$ is
approximately $150\,$MeV below the strong decay threshold $B^-\bar {B^*}^{0}$ and $105\,$MeV below
the electromagnetic decay threshold $B^- \bar B^0 \gamma$....
Dr
Guang-Juan Wang
(Peking University)
20/08/2019, 17:00
Session 3: Exotic hadrons and candidates
Parallel
In this work, we systematically calculate the mass spectra of the $S$-wave fully heavy tetraquark states $bb\bar b\bar b$, $cc\bar c\bar c$, and $bb\bar c\bar c$ in two nonrelativistic quark models. A tetraquark state may be an admixture of a $6_c-\bar 6_c$ state and a $\bar 3_c-3_c$ one, where $6_c-\bar 6_c$($\bar 3_c-3_c$) denotes the color configuration with a $6_c$ ($\bar 3_c$) diquark and...
Mr
Lu Meng
(Peking Universtiy)
20/08/2019, 17:20
Session 3: Exotic hadrons and candidates
Parallel
We employ the heavy hadron chiral perturbation theory (HHChPT) to calculate the $\Sigma_c\bar{D}^{(\ast)}$ potentials to the next-to-leading order. The contact, the one-pion exchange and the two-pion exchange interactions are included. We keep the mass splittings between the heavy quark spin symmetry (HQSS) multiplets in calculation. We show that neglecting the heavy quark symmetry (HQS)...
Prof.
Eulogio Oset
(IFIC, University of Valencia)
21/08/2019, 08:30
Session 3: Exotic hadrons and candidates
Leading parallel
We have investigated Ωc states that are dynamically generated from the meson-baryon interaction. We
use an extension of the local hidden gauge to obtain the interaction from the exchange of vector mesons.
We show that the dominant terms come from the exchange of light vectors, where the heavy quarks are
spectators. This has as a consequence that heavy quark symmetry is preserved for the...
Daniel Molnar
(Johannes Gutenberg Universität-Mainz)
21/08/2019, 08:55
Session 3: Exotic hadrons and candidates
Parallel
In this work, we use the dispersion theory to provide a physical description of recent BESIII data on the reaction $ e^+ e^- \to \psi (2S) \, \pi^+ \, \pi^-$ [1].
Taking into account explicitly the effects of charged exotic intermediate states in the $t$- and $u$-channels as well as the two-pion final state interaction, we describe the invariant mass distribution for four different $e^+ e^-$...
Dr
Qi Huang
(University of Chinese Academy of Sciences)
21/08/2019, 09:15
Session 3: Exotic hadrons and candidates
Parallel
In 2017, the BESIII Collaboration announced the observation of charged charmonium-like structure in the $\psi(3686)\pi^\pm$ invariant mass spectrum of the $e^+ e^- \to \psi(3686) \pi^+ \pi^-$ process at different energy points, which makes a precise study of the $e^+ e^- \to \psi(3686) \pi^+ \pi^-$ process based on the initial single pion emission (ISPE) mechanism become possible. In my...
Dr
Alberto Martinez Torres
(Universidade de São Paulo)
21/08/2019, 09:35
Session 3: Exotic hadrons and candidates
Parallel
In a recent work we have studied three-body scattering, considering the $DDK$ system, in a coupled channel approach. All input two-body scattering matrices have been obtained by solving Bethe-Salpeter equations for different channels coupling to same quantum numbers. The lowest order amplitudes for the two-body subsystems are obtained from a Lagrangian based on the heavy quark symmetry. We...
Mr
Sen Jia
(Beihang University)
21/08/2019, 10:45
Session 3: Exotic hadrons and candidates
Leading parallel
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. From February to July 2018, the machine has...
Dr
Sachiko Takeuchi
(Japan College of Social Work)
21/08/2019, 11:10
Session 3: Exotic hadrons and candidates
Parallel
The recent experiments by LHCb indicates that the $NJ/\psi$-$\Lambda_c \bar D$-$\Sigma_c \bar D$ or $q^3c\bar c$ systems have a rich spectrum [1].
Theoretically also, it has been found that a quark cluster model, or a hadron model which includes the five-quark mode, gives narrow resonances or cusps in the $Y_c \bar D$ scattering [2,3].
Such a structure appears because the three light quarks...
Prof.
Hongxia Huang
(Nanjing Normal University)
21/08/2019, 11:30
Session 3: Exotic hadrons and candidates
Parallel
The LHCb collaboration published new data on penta-quark states: three narrow states Pc(4312), Pc(4440), Pc(4457) are claimed. All of these states are higher than the threshold of NJ/psi threshold and appeared as narrow resonances in the scattering channel N-J/psi. We had analyzed these states in EPJC(2016)76:624 and PRD99(2019)014010. In this report we will reanalyze these states and the...
Dr
Li Ma
(HISKP, Universität Bonn)
21/08/2019, 11:50
Session 3: Exotic hadrons and candidates
Parallel
Through the Born-Oppenheimer Approximation, we have performed a comprehensive investigation of the DD*K, BB*K and BBB* molecular states. In the framework of One-Pion Exchange model as well as the treatments of the coupled-channel efects and S-D wave mixing, we find loosely bound tri-meson molecular states of these systems with some specific isospin configuration. We also predict that a...
