An understanding of analyte–coating interactions is needed in order to be able to predict the sensitivity and selectivity of coating materials considered for use in mass‐sensitive devices such as the ...quartz microbalance. Models are reviewed for the sensor response based on solubility parameters and calculated energies for functionalized coatings and supramolecular cavities (e.g., the substituted tetraazaparacyclophane shown in the Figure).
We present an analysis of the process \(e^{+}e^{-}\to\pi^{+}\pi^{-}\Upsilon(nS)\) (where \(n\) = 1, 2, or 3) reconstructed in \(19.6\rm\) \(\rm fb^{-1}\) of Belle II data during a special run of the ...SuperKEKB collider at four energy points near the peak of the \(\Upsilon(10753)\) resonance. By analyzing the mass distribution of the \(\pi^+\pi^-\Upsilon(nS)\) system and the Born cross sections of the \(e^{+}e^{-}\to\pi^{+}\pi^{-}\Upsilon(nS)\) process, we report the first observation of \(\Upsilon(10753)\) decays to the \(\pi^{+}\pi^{-}\Upsilon(1S)\) and \(\pi^{+}\pi^{-}\Upsilon(2S)\) final states, and find no evidence for decays to \(\pi^{+}\pi^{-}\Upsilon(3S)\). Possible intermediate states in the \(\pi^+\pi^-\Upsilon(1S,2S)\) transitions are also investigated, and no evidence for decays proceeding via the \(\pi^\mp Z_b^\pm\) or \(f_0(980)\Upsilon(nS)\) intermediate states is found. We measure Born cross sections for the \(e^{+}e^{-}\to\pi^{+}\pi^{-}\Upsilon(nS)\) process that, combined with results from Belle, improve the precision of measurements of the \(\Upsilon(10753)\) mass and width by nearly a factor of two to \((10756.3\pm2.7\pm0.6)\) MeV/\(c^2\) and \((29.7\pm8.5\pm1.1)\) MeV, respectively. The relative ratios of the Born cross sections at the \(\Upsilon(10753)\) resonance peak are also reported for the first time.
We report measurements of the $\bar{B}^0 \to D^{*+} \ell^{-} \bar{\nu}_l$ and
$B^- \to D^{0} \ell^{-} \bar{\nu}_l$ processes using 34.6 fb$^{-1}$ of
collision events recorded by the Belle II ...experiment at the SuperKEKB
asymmetric-energy $e^+ e^-$ collider. For the $B^-\to D^{0}\ell^-\bar\nu_\ell$
channel, we present first studies that isolate this decay from other
semileptonic processes and backgrounds. We report a measurement of the
$\bar{B}^0 \to D^{*+} \ell^{-} \bar{\nu}_l$ branching fraction and obtain
${\cal B}(\bar{B}^0 \to D^{*+} \ell^{-} \bar{\nu}_l) = \left(4.60 \pm
0.05_{\mathrm{stat}}\pm0.17_{\mathrm{syst}} \pm 0.45_{\pi_s}\right) \%$, in
agreement with the world average. Here, the uncertainties are statistical,
systematic, and related to slow pion reconstruction, respectively. The
systematic uncertainties are limited by the statistics of auxiliary
measurements and will improve in the future. We also report differential
branching fractions in five bins of the hadronic recoil parameter $w$ for
$\bar{B}^0 \to D^{*+} \ell^{-} \bar{\nu}_l$, unfolded to account for resolution
and efficiency effects.
Tag-side reconstruction is an important method for reconstructing $B$ meson
decays with missing energy. The Belle II tag-side reconstruction algorithm,
Full Event Interpretation, relies on a ...hierarchical reconstruction of $B$ meson
decays with multivariate classification employed at each stage of
reconstruction. Given the large numbers of classifiers employed and decay
chains reconstructed, the performance of the algorithm on data and simulation
differs significantly. Here, calibration factors are derived for hadronic
tag-side $B$ decays by measuring a signal side decay, $B \rightarrow X\ell
\nu$, in $34.6$ fb$^{-1}$ of Belle II data. For a very loose selection on the
tag-side $B$ multivariate classifier, the calibration factors are $0.65 \pm
0.02$ and $0.83 \pm 0.03$ for tag-side $B^{+}$ and $B^{0}$ mesons,
respectively.
The reconstruction of tau-pair production, $e^{+}e^{-} \to \tau^{+}\tau^{-}$,
from the subsequent 3-prong ($\tau^{+} \rightarrow \pi^{+} \pi^{-} \pi^{+}
\bar{\nu}_{\tau}$) and 1-prong ($\tau^{-} \to ...\ell^{-} \bar{\nu}_{\ell}
\nu_{\tau}$, $\tau^{-} \to h^{-} \nu_{\tau}$ or $\tau^{-} \to \pi^{-} \pi^0
\nu_{\tau}$) decays, is presented using 8.8 fb$^{-1}$ of $e^{+}e^{-}$ collision
data of Belle II at the center-of-mass energy $\sqrt{s} = m_{\Upsilon(4S)}$.
The pseudomass technique developed by the ARGUS experiment is used to measure
the $\tau$-lepton mass $m_{\tau}$ in the 3-prong $\tau^{+} \to \pi^{+} \pi^{-}
\pi^{+} \bar{\nu}_{\tau} $ decay, resulting in $m_{\tau} = 1777.28 \pm
0.75~{\rm (stat.)} \pm 0.33 ~{\rm (sys.)}~{\rm{MeV}/\rm{c}^2}$.
We search for the rare decay \(B^{+}\rightarrow K^{+}\nu\bar{\nu}\) in a \(362\ \rm{fb}^{-1}\) sample of electron-positron collisions at the \(\Upsilon(4S)\) resonance collected with the Belle II ...detector at the SuperKEKB collider. We use the inclusive properties of the accompanying \(B\) meson in \(\Upsilon(4S) \to B\kern 0.18em\overline{\kern -0.18em B}{}\) events to suppress background from other decays of the signal \(B\) candidate and light-quark pair production. We validate the measurement with an auxiliary analysis based on a conventional hadronic reconstruction of the accompanying \(B\) meson. For background suppression, we exploit distinct signal features using machine learning methods tuned with simulated data. The signal-reconstruction efficiency and background suppression are validated through various control channels. The branching fraction is extracted in a maximum likelihood fit. Our inclusive and hadronic analyses yield consistent results for the \(B^{+}\rightarrow K^{+}\nu\bar{\nu}\) branching fraction of \(\left2.7\pm 0.5(\mathrm{stat})\pm 0.5(\mathrm{syst})\right \times 10^{-5}\) and \(\left1.1^{+0.9}_{-0.8}(\mathrm{stat}){}^{+0.8}_{-0.5}(\mathrm{syst})\right \times 10^{-5}\), respectively. Combining the results, we determine the branching fraction of the decay \(B^{+}\rightarrow K^{+}\nu\bar{\nu}\) to be \(\left2.3 \pm 0.5(\mathrm{stat})^{+0.5}_{-0.4}(\mathrm{syst})\right\times 10^{-5}\), providing the first evidence for this decay at \(3.5\) standard deviations. The combined result is \(2.7\) standard deviations above the standard model expectation.
We report a case of severe lumbar artery bleeding following percutaneous renal biopsy. A 68-year-old man with a history of rheumatoid arthritis, gold therapy, and Staphylococcus aureus bacteremia ...underwent a percutaneous renal biopsy to evaluate nephrotic syndrome and renal insufficiency. Following the procedure, he developed signs of severe hemorrhage. A selective renal angiogram revealed an intrarenal bleeding site that was occluded by selective embolization. The patient failed to stabilize however, and repeat angiography was performed two days later. A lumbar artery was identified as a second bleeding site, and was also occluded by selective embolization. The bleeding was controlled, but the patient developed serious complications and died five days later.
We utilize a sample of 34.6 fb$^{-1}$, collected by the Belle II experiment
at the SuperKEKB asymmetric energy $e^+e^-$ collider, to search for the $B^+
\to \phi K^+$, $B^+ \to \phi K^{*+}$, $B^0 \to ...\phi K^0_S$, and $B^0 \to \phi
K^{*0}$ decays. Charmless hadronic $B$ decays represent an important part of
the Belle II physics program, and are an ideal benchmark to test the detector
capabilities in terms of tracking efficiency, charged particle identification,
vertexing, and advanced analysis techniques. Each channel is observed with a
significance that exceeds 5 standard deviations, and we obtain measurements of
their branching ratios that are in good agreement with the world averages. For
the $B \to \phi K^*$ modes, we also perform a measurement of the longitudinal
polarization fraction $f_L$.
We present a measurement of the ratio \(R_\mu = \mathcal{B}(\tau^-\to \mu^-\bar\nu_\mu\nu_\tau) / \mathcal{B}(\tau^-\to e^-\bar\nu_e\nu_\tau)\) of branching fractions \(\mathcal{B}\) of the \(\tau\) ...lepton decaying to muons or electrons using data collected with the Belle II detector at the SuperKEKB \(e^+e^-\) collider. The sample has an integrated luminosity of 362 fb\(^{-1}\) at a centre-of-mass energy of 10.58 GeV. Using an optimised event selection, a binned maximum likelihood fit is performed using the momentum spectra of the electron and muon candidates. The result, \(R_\mu = 0.9675 \pm 0.0007 \pm 0.0036\), where the first uncertainty is statistical and the second is systematic, is the most precise to date. It provides a stringent test of the light-lepton universality, translating to a ratio of the couplings of the muon and electron to the \(W\) boson in \(\tau\) decays of \(0.9974 \pm 0.0019\), in agreement with the standard model expectation of unity.
We report a determination of the CKM angle \(\phi_{3}\), also known as \(\gamma\), from a combination of measurements using samples of up to 711~fb\(^{-1}\) from the Belle experiment and up to ...362~fb\(^{-1}\) from the Belle II experiment. We combine results from analyses of \(B^+\to DK^+, B^+\to D\pi^+\), and \(B^+ \to D^{*}K^+\) decays, where \(D\) is an admixture of \(D^0\) and \(\overline{D}{}^{0}\) mesons, in a likelihood fit to obtain \(\phi_{3} = (78.6^{+7.2}_{-7.3})^{\circ}\). We also briefly discuss the interpretation of this result.
