We search for lepton-flavor and lepton-number-violating τ decays into a lepton (ℓ= electron or muon) and two charged mesons (h,h′=π± or K±) using 854 fb−1 of data collected with the Belle detector at ...the KEKB asymmetric-energy e+e− collider. We obtain 90% confidence level upper limits on the τ→ℓhh′ branching fractions in the range (2.0–8.4)×10−8. These results improve upon our previously published upper limits by factors of about 1.8 on average.
To clarify the usefulness of three-dimensional (3D) ultrasound in the assessment of the fetal head and brain, according to 3D ultrasound surface reconstruction, multiplanar image analysis, ...three-dimensional angiography, and volume calculation.
We examined 326 normal fetuses between 10 and 40 weeks of gestation using 3D ultrasound (Voluson, 530D, Medison, Seoul, Korea), mainly with transvaginal 3D transducer. Fetal head structures, such as the skull, brain structure, and brain circulation, were presented by surface mode, multiplanar imaging mode, and three-dimensional Doppler mode. After automatic volume acquisition of the fetal head, image analyses were performed off-line, and 3D View software was used for volume imaging of the lateral ventricle and choroid plexus in randomly selected 30 normal fetuses. Seven fetuses with intracranial abnormalities were evaluated by 3D ultrasound functions.
Surface mode of 3D ultrasound objectively depicted in vivo development of the cranial bones and formation of the cranial sutures and fontanelles in normal fetuses. Multiplanar image analysis of the brain structure presented a fetal brain in more cutting sections than conventional 2D ultrasound. Transvaginal 3D angiography was successful in 13% of normal fetuses and rotation of 3D circulatory image allowed the analysis of the intracranial vessels. Volume imaging showed the intracranial structures, such as the lateral ventricle and choroid plexus. Intracranial abnormalities were longitudinally evaluated by 3D ultrasound and objective images helped in reaching prenatal diagnoses.
Advanced 3D ultrasonography and software for volume analysis can provide additional objective information about the fetal skull formation, brain structure, and brain circulation.
Using a data sample of 980 fb–1 of $e^+e^–$ annihilation data taken with the Belle detector operating at the KEKB asymmetric-energy $e^+e^–$ collider, we report the results of a study of the decays ...of the $Ω^0_c$ charmed baryon into hadronic final states. We report the most precise measurements to date of the relative branching fractions of the $Ω^0_c$ into $Ω^–π^+π^0, Ω^–π^+π^–π^+$, $Ξ^–K^–π^+π^+$, and $Ξ^0K^–π^+$, as well as the first measurements of the branching fractions of the $Ω^0_c$ into $Ξ^–\overline{K}^0π^+$, $Ξ^0\overline{K}^0$, and $Λ\overline{K}^0\overline{K}^0$, all with respect to the $Ω^–π^+$ decay. In addition, we investigate the resonant substructure of these modes. Finally, we present a limit on the branching fraction for the decay $Ω^0_c→Σ^+K^–K^–π^+$.
First experience with Belle II Aerogel RICH detector Mrvar, M.; Adachi, I.; Burmistrov, L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
The Aerogel Ring-Imaging Cherenkov (ARICH) detector provides particle identification information in the forward endcap part of Belle II. It efficiently separates charged kaons from pions for momenta ...between 0.5GeV/c and 4.0GeV/c. Optical photons are emitted in a double layer aerogel radiator and detected by Hybrid Avalanche Photo Detectors. ARICH was installed in Belle II at the end of 2017, the first phase of a complex detector calibration of electronic signals and preparation for physics signals calibration has been successfully concluded. Cherenkov rings, created by cosmic rays as well as by charged particles from beam collisions, have been observed. The kaon identification efficiency using D±∗ decays has been studied and its calibration is expected by the end of the commissioning phase when sufficient data is available.
•The commissioning phase of Belle II is completed.•Cherenkov rings, created by cosmic rays and at collisions, were observed in ARICH.•The ARICH performance is studied using charged kaons and pions from D̂{+*} decays
Observation of the Decay Bs0 → K0 K ¯ 0 Schwartz, A. J.; Aihara, H.; Ayad, R. ...
Physical review letters,
04/2016, Letnik:
116, Številka:
16
Journal Article
Recenzirano
Odprti dostop
We measure the decay B$^{0}_{s}$ → K0K¯0 using data collected at the Υ(5S) resonance with the Belle detector at the KEKB e+e– collider. The data sample used corresponds to an integrated luminosity of ...121.4 fb–1. We measure a branching fraction B(B$^{0}_{s}$ → K0K¯0) = 19.6$^{+5.8}_{–5.1}$(stat.) ± 1.0(sys.)±2.0(NB$^{0}_{s}$B¯$^{0}_{s}$)×10–6 with a significance of 5.1 standard deviations. Here, this measurement constitutes the first observation of this decay.
Search for the decay B s 0 → η η Nath, K. J.; Adachi, I.; Aihara, H. ...
Physical review. D,
01/2022, Letnik:
105, Številka:
1
Journal Article
Recenzirano
We report results from a search for the decay $B^0_s$ → $ηη$ using 121.4 fb-1 of data collected at the $Υ(5S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We do ...not observe any signal and set an upper limit on the branching fraction of 14.3 x 10-5 at 90% confidence level. This result represents a significant improvement over the previous most stringent limit.
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