ExHIC10 Abstracts
ExHIC10 home
- Su Houng Lee
--- Theoretical aspects of exotic hadrons
- Che-Ming Ko
--- Exotic hadrons from heavy-ion collisions (tentative) / Overview of heavy-ion collision physics
- Akira Ohnishi
--- Lambda-Lambda correlation in (K-,K+) reaction and in heavy-ion collisions
- Alberto Martinez Torres
--- 3-body structure of exotic hadrons
- Marina Nielsen
--- QCD sum rule study of exotic hadrons (tentative)
- Huan Zhong Huang
--- Exotic Particle Searches with STAR at RHIC
Relativistic heavy ion collisions at RHIC produce high temperature and energy density partonic matter. The hadronization of the bulk partonic matter is rapid and likely through coalescence or recombination processes. There is a unique opportunity to search for various exotic particles in these collisions at RHIC. I will report on status and future perspectives of searches for exotic particles at RHIC.
- In-Kwon Yoo
--- Exotic search at RHIC (tentative)
- Choongjae Yoon
--- Probing Lambda-Lambda potential
One interesting phenomenon in the scattering experiment is a resonance.
In its simplest form, a narrow resonance leads to a bump in the cross
section. And its phase shift rapidly change from 0 to 180 degree. In our
previous work, we have studied $^{12}$C($K^-$, $K^+$ $ \Lambda \Lambda$)
reaction by using a scintillating fiber (SCIFI) active target. The experiment
(KEK-PS E522) was performed at the KEK proton synchrotron using 1.66 GeV/$c$
separated $K^-$ beams. The $\Lambda\Lambda$ events were observed in the SCIFI
target via the ($K^-$, $K^+$)reactions. The ($K^-$, $K^+$) reactions were
tagged by a Kaon-spectrometer. In the production runs of 2002, approximately 9
$\times$ 10$^9$ $K^-$ beam particles were injected into the SCIFI target and
then, 4 .5 $\times$ 10$^4$ ($K^-$, $K^+ $) events were obtained. Based on the
tagged ($K^-$, $K^+$) events, 68 two-$\Lambda$ events for the $K^+$ momentum
region, 0.9 GeV/$c$ $\le$ $P_{K^+}$ $\le$ 1.3 GeV/$c$, were finally retained.
From the analysis of these data, we observed an enhancement
near $\Lambda\Lambda$ threshold as reported in a previous KEK-PS experiment.
We have fitted the $\Lambda\Lambda$ invariant mass spectrum by using
a square of $S$-wave $\Lambda\Lambda$ wave function and combinatorial
background in which the wave function was considered as a sine wave form.
Phase shift of the $\Lambda\Lambda$ wave function which described by
scattering length and effective range were determined in the fitting
process. Comparing the predicted values of potential models, the determined
value of the scattering length $-$0.10, and the effectiverange 13.90 fm
is the most consistent with the values predicted by using a series of the
Nijmegen soft core modles NSC97's. However the predicted value by using the
Nijmegen hard core model ND (G-matrix), the extended soft core model ESC00,
and the Kyoto-Niigata FSS model predictions are out of three standard
deviations from the determined scattering parameters. Further, we extracting
$\Lambda\Lambda$potential from the $\Lambda\Lambda$ invariant mass spectrum.
In this talk, I will present a completed analysis result for the
$\Lambda\Lambda$ scattering parameters together with undergoing study for the
$\Lambda\Lambda$ potential in a low energy $\Lambda$$-$$\Lambda$ scattering.
- Youngjoon Kwon
--- Exotic search at Belle
With world-highest luminosity of the KEKB e+e- collider, the Belle experiment has made not only a series of high-statics studies of CP violations and rare decays in the heavy-flavor systems, it has also observed many new particles and exotic states. In this presentation, we will go review the searches and discoveries of exotic particles from Belle.
- Atsushi Hosaka
--- Algebraic approach to chiral symmetry for hadron properties
- Tetsuo Hyodo
--- Exotic hadrons and hadronic molecules in s-wave chiral dynamics
- Chiho Nonaka
--- Fragmentation and recombination for exotics in heavy ion collisions
- Shigehiro Yasui
--- Exotic hadrons with heavy-quarks (tentative)
- Kenichi Imai
--- Search for H-resonance and other exotics at J-PARC
Based on the past experiments at KEK-PS and SPring-8, we are planning new experiments to search for H-resonance in Lambda-Lambda invariant mass measurement and pentaquaks at J-PARC. Following a brief review of past works, a prospect of J-PARC experiments is discussed.
- Masayuki Niiyama
--- Exotic search at SPring8 (tentative)
- Sungtae Cho
--- Classical strongly coupled quark-gluon plasma
- Shunzo Kumano
--- Exotic hadrons from fragmentation functions
- Philipp Gubler
--- QCD Sum Rules in a Bayesian approach
QCD sum rules are analyzed using the Maximum Entropy Method, which makes it possible to have direct access to the spectral functions of two-point correlators. Using the operator product expansion, QCD sum rules allow one to calculate the correlators only in the deep euclidean region, which is connected to the physical region by a dispersion relation. In the traditional analysis of QCD sum rules, one then employs the ``pole + continuum" ansatz for the physical region of the spectral function and extracts the position and residue of the low-lying pole. Our approach is different as we do not need to make any assumptions about the explicit form of the spectral function, but can obtain the most probable spectral function directly by using the Maximum Entropy Method.
Compared with the traditional analysis, this method has many advantages: As we have direct access to the spectral function, we do not have to deal with results depending on ``unphysical" parameters such as the Borel mass or the threshold parameter, which appears in the ``pole + continuum" ansatz. Another advantage is that, by examining the behavior of the spectral function, we are able to distinguish narrow resonances from scattering states.
As a first test of the applicability of our method, we have analyzed the sum rules of the rho-meson, a case in which the traditional sum rules are known to work well. Our calculation shows a clear peak around 800 MeV, which confirms the older sum rule results and shows that the Maximum Entropy Method can be successfully applied to QCD sum rules.
- Alexander Titov
--- Charm production in proton reactions (tentative)
- Maya Shimomura
--- KT and quark number scaling of v2