K. Miyabayashi

Belle electromagnetic calorimeter

Abstract We report the performance of the Belle electromagnetic calorimeter for the first three years operation. Good mass resolutions for π 0 and η are obtained to be 4.8 and 12.1 MeV /c 2 , respectively. The degradation of light output due to the radiation damage is small, about 3% for the radiation dose of 40 rad . These performances promise further study of B physics with neutral particle reconstruction.

Observation of B^+ ¿ ¿K^+

We report the first observation of the charmless hyperonic B decay, B+-->LambdaLambdaK+, using a 140 fb(-1) data sample recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB (e+)(e-) collider. The measured branching fraction is B(B+-->LambdaLambdaK+) = (2.91(+0.90)(-0.70) +/- 0.38) x 10(-6). We also perform a search for the related decay mode B+-->LambdaLambdapi+, but do not find a significant signal. We set a 90% confidence-level upper limit of B(B+-->LambdaLambdapi+) < 2.8 x 10(-6).

A detailed test of the CsI(Tℓ) calorimeter for BELLE with photon beams of energy between 20 MeV and 5.4 GeV

Abstract The results of a beam test of a prototype of the BELLE CsI(Tl) calorimeter are reported. The test used beams of photons with energies spanning the range from 20 MeV to 5.4 GeV, produced at ROKK-1M facility of the Budker Institute of Nuclear Physics. The single-counter energy-equivalent noise was measured to be ∼200 keV. The design goals for the energy resolution, e.g. 4% at 20 MeV and 1.7% at 5.4 GeV, were achieved using the sum of energy deposits in a 5×5 crystal matrices with a single crystal energy threshold of 0.5 MeV; the summed energy deposit measured in the array corresponds to 97±2% of the incident photon energy over the entire energy range. The average position resolution for 470 MeV energy photons was measured to be 8 mm.

Exotic hadrons with heavy flavors: X, Y, Z, and related states

In the past decade, exotic hadrons with charm and bottom flavors have been extensively studied both in experiments and in theories. In this review, we provide topical discussions by selecting

Study of the radiation hardness of CsI(Tl) crystals for the BELLE detector

X,Y,Z

Study of B-+/--> DCPK +/- and (DCPK +/-)-K-* decays

particles, to which Belle has made important contributions. These are

Charged particle multiplicities of quark and gluon jets in e+ e- annihilation at TRISTAN

X(3872)

A study of single photon production in e+e− collisions at s=58 GeV with the TOPAZ detector at TRISTAN

,

Measurement of the cross-section and forward-backward charge asymmetry for the b and c-quark in \(e^+e^-\) annihilation with inclusive muons at \(\sqrt{s} = 58\) GeV

Y(4260)

Radiation hardness test of Pr:LuAG and BSO scintillators

,