Related papers: Experimental Evidence for the Pentaquark
The recently observed pentaquark baryons $\Theta^{+}$ and $\Xi^{--}$ are studied in the dual gravity theory of QCD. By developing a general formulation useful for studying the branched string web in a curved space, simple mass formulae of…
In this talk, after a short overview of the history of the discovery of tetra-quarks and penta-quarks, we will discuss a possible interpretation of such states in the framework of a 40-years-old "string junction" picture that allows a…
We study the stability of pentaquarks within a schematic model based on SU(3) color symmetry, by taking into account algebraic arguments leading to a chromoelectric interaction containing two- and three-body parts. It has already been…
I first give a brief overview of the status of exotic hadron search so far. Then I review the recent theoretical development on pentaquarks. Finally I emphasize that none of theoretical formalisms predicts the existence of $\Theta$…
If Jaffe and Wilczek's diquark picture for $\Theta_5$ pentaquark is correct, there should also exist a $SU_F$(3) pentaquark octet and singlet with no orbital excitation between the diquark pair, hence $J^P={1/2}^-$. These states are lighter…
I give a brief overview of experimental studies of the spectrum and the structure of the excited states of the nucleon and what we learn about their internal structure. The focus is on the effort to obtain a more complete picture of the…
It is shown that the exotic non-qqq hadrons of pentaquark $qqqq\bar{q}$ states can be clearly distinguished from the conventional qqq-baryon resonances or their hybrids if the flavor of $\bar{q}$ is different from any of the other four…
A brief review of the latest developments in the spectroscopy of heavy quarks is presented. The current status of the recently `discovered' pentaquarks is also discussed.
Recent experimental evidence for the Theta^+(1540) has given rise to much theoretical interest in exotic baryons. The Theta^+ is a baryon that has strangeness S=+1, meaning that it contains an anti-strange quark. Thus it cannot be…
It is shown that all predictions for the light scalars, based on their four-quark nature, are supported by experiment. The future research program is outlined also.
We investigate light meson bound state contributions to six quark Green's functions and establish that the latter has poles corresponding to baryon bound states. We estimate light baryon masses including the Roper resonance. Constituent…
A systematic lowering in mass of strangeness ambiguous $pK^0_S$ peaks relative to the $nK^+$ is noted. We discuss how measurement of $\gamma p\to \Theta^+ K^0_S\to p K^0_S K^0_S \to p\pi^+\pi^-\pi^+\pi^-$ in association with $\gamma p\to…
Using the bound state version of the topological soliton model for the baryons we show that the existence of a bound (or quasi-bound) $\bar D$-soliton state leads to the possibility of having hidden charm pentaquarks with quantum numbers…
The past decades witnessed the golden era of hadron physics. Many excited open heavy flavor mesons and baryons have been observed since 2017. We shall provide an updated review of the recent experimental and theoretical progresses in this…
We highlight topical issues in hyperon spectroscopy that will be accessible when a secondary beam of neutral kaons is created in Hall D at Jefferson Lab as proposed to the JLab Program Advisory Committee. The new beam will have a flux of…
Claims concerning the possible discovery of the \Theta^+ pentaquark, with minimal quark content uudd\bar{s}, have motivated our comprehensive study into possible pentaquark states using lattice QCD. We review various pentaquark…
Pentaquark states in lattice QCD probably lie close in energy to two particle scattering states. Correctly identifying the resonant state is a challenging, yet tractable, problem given the terascale computing facilities available today. We…
The LHCb collaboration have recently updated their analysis of the resonant $J/\psi p$ mass spectrum in the decay $\Lambda_b^0 \to J/\psi p K^-$, making use of their combined Run 1 and Run 2 data. In the updated analysis, three narrow…
Here we review empirical evidence for the possible existence of tachyons, superluminal particles having m^2 < 0: The review considers searches for new particles that might be tachyons, as well as evidence that neutrinos are tachyons from…
This paper reviews the current status of experimental measurements of radiative kaon decays. Several experiments at BNL, CERN and FNAL have recently or will soon complete data collection; as a result, several new results are available.