Case for quarkyoniclike matter from a constituent quark model
Not Available
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Engineering topics
Lee, Su Houng
Publications and source records attributed to Lee, Su Houng.
Charmed hadron production in an improved quark coalescence model
Here, we study the production of charmed hadrons $D^0$ and $Λ^+_c$ in relativistic heavy ion collisions using the charm quark coalescence. Besides taking into consideration changing hadron sizes in a hot dense medium, which results in an enhanced coalescence probability for charm quarks of very low transverse momenta, we also include the collective flow effect on heavier resonances, which leads to a shift of massive charmed resonances to larger transverse momenta. Including the conversion of charm quarks not undergoing coalescence to hadrons by independent fragmentation, we obtain a good description of the measured yield ratio $Λ^+_c/D^0$ as a function of transverse momentum in Au + Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV by the STAR Collaboration at the Relativistic Heavy Ion Collider.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
D mesons in a magnetic field
In this paper, we investigate the mass spectra of open heavy flavor mesons in an external constant magnetic field within QCD sum rules. Spectral Ansatze on the phenomenological side are proposed in order to properly take into account mixing effects between the pseudoscalar and vector channels, and the Landau levels of charged mesons. The operator product expansion is implemented up to dimension-5 operators. As a result, we find for neutral D mesons a significant positive mass shift that goes beyond simple mixing effects. In contrast, charged D mesons are further subject to Landau level effects, which together with the mixing effects almost completely saturate the mass shifts obtained in our sum rule analysis.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Free energy versus internal energy potential for heavy quark systems at finite temperature
Not Available
Song, Taesoo (ORCID:0000000153217869)↗
QCD Sum Rules for Magnetically Induced Mixing between ηc and J/ψ
We investigate the properties of charmonia in strong magnetic fields by using QCD sum rules. We show how to implement the mixing effects between ηc and J/ψ on the basis of field-theoretical approaches, and then show that the sum rules are saturated by the mixing effects with phenomenologically determined parameters. Consequently, we find that the mixing effects are the dominant contribution to the mass shifts of the static charmonia in strong magnetic fields.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Exotics from Heavy Ion Collisions
Discriminating hadronic molecular and multi-quark states is a long standing problem in hadronic physics. We propose here to utilize relativistic heavy ion collisions to resolve this problem, as exotic hadron yields are expected to be strongly affected by their structures. Using the coalescence model, we find that the exotic hadron yield relative to the statistical model result is typically an order of magnitude smaller for a compact multi-quark state, and larger by a factor of two or more for a loosely bound hadronic molecule. We further find that some of the newly proposed heavy exotic states could be produced and realistically measured at RHIC and LHC.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
A QCD Sum Rule Approach with an Explicit Di-quark field
In hadron phenomenology, diquark structures can be an important degree of freedom in certain configurations. We investigate the possibility that the diquark structure can be treated as an elementary field in certain configurations. To start with, we assume that {Lambda} is composed of a spectator strange quark and a diquark. We construct a QCD sum rule for {Lambda}, where the input parameters are the diquark mass and its condensate, in addition to other parameters of QCD sum rules. We find good Borel curve for the {Lambda} mass for certain combinations of the diquark mass and condensate, and that smaller diquark condensate is needed when the diquark mass is increased to maintain the good Borel curve. The same sets of diquark mass and condensate are found to work well for {Lambda}{sub c} and {Lambda}{sub b}.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Twist 4 Matrix Elements
This work summarizes previous attempts to extract the nucleon expectation value of twist-4 operators from CERN and SLAC data. Speculations about how the new data from Jlab upgrade can reduce the large uncertainties are discussed.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Diquarks: A QCD sum rule perspective
We propose a phenomenological QCD sum rule with an explicit diquark field to investigate the essential ingredients inside the hadrons. By introducing the mass m{sub {phi}} and the condensate <{phi}{sup 2}> for the diquark field as parameters in the model, we find that the sum rule works well for {Lambda}, {Lambda}{sub c}, and {Lambda}{sub b}. This implies that these {Lambda} baryons can be represented by a diquark and a quark configuration. We also find that there is a duality relation among the parameters (m{sub {phi},}<{phi}{sup 2}>) for which the sum rule is equally good. In the limit when <{phi}{sup 2}>=0, we find m{sub {phi}=}400 MeV, which can be thought of as the constituent diquark mass.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗