Sho Ozaki

Charmonium Spectroscopy in Strong Magnetic Fields by QCD Sum Rules: S-Wave Ground States

We investigate quarkonium mass spectra in external constant magnetic fields by using QCD sum rules. We first discuss a general framework of QCD sum rules necessary for properly extracting meson spectra from current correlators computed in the presence of strong magnetic fields, that is, a consistent treatment of mixing effects caused in the mesonic degrees of freedom. We then implement operator product expansions for pseudoscalar and vector heavy-quark current correlators by taking into account external constant magnetic fields as operators and obtain mass shifts of the lowest-lying bound states η c and J / ψ in the static limit with their vanishing spatial momenta. Comparing results from QCD sum rules with those from hadronic effective theories, we find that the dominant origin of mass shifts comes from a mixing between η c and J / ψ with a longitudinal spin polarization, accompanied by other subdominant effects such as mixing with higher excited states and continua.

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.

Measurement of the γ→p→K+Λ reaction at backward angles

Cross sections for the

Magnetic interaction induced by the anomaly in kaon-photoproductions

\gamma p \to K^+ \Lambda

Transport coefficients from the QCD Kondo effect

have been measured at backward angles using linearly polarized photons in the range 1.50 to 2.37 GeV. In addition, the beam asymmetry for this reaction has been measured for the first time at backward angles. The

Lattice study of J/psi- phi scattering at low energies to search for narrow resonance

\Lambda

A study of mixing properties of a1(1260) meson

was detected at forward angles in the LEPS spectrometer via its decay to

Erratum: Coupled-channel analysis for ϕ photoproduction with Λ(1520) [Phys. Rev. C 80, 035201 (2009)]

p\pi^-

Reaction dynamics for photoproductions of baryon resonances

and the K^+ was inferred using the technique of missing mass. These measurements, corresponding to kaons at far backward angles in the center-of-mass frame, complement similar CLAS data at other angles. Comparison with theoretical models shows that the reactions in these kinematics provide further opportunities to investigate the reaction mechanisms of hadron dynamics.

THE ROLE OF THE QCD ANOMALY IN KAON PHOTOPRODUCTION

We study the role of magnetic interaction in the photoproduction of the kaon and hyperon. We find that the inclusion of a higher order diagram induced by the Wess–Zumino–Witten term has a significant contribution to the magnetic amplitude, which is compatible to the observed photon asymmetry in the forward angle region. This enables us to use the K∗ coupling constants which have been determined in a microscopic way rather than the phenomenological ones which differ largely from the microscopic ones.