We determine the CKM matrix-element magnitude \(|V_{cb}|\) using \(\overline{B}^0\to D^{*+}\ell^-\bar\nu_\ell\) decays reconstructed in \(189 \, \mathrm{fb}^{-1}\) of collision data collected by the ...Belle II experiment, located at the SuperKEKB \(e^+e^-\) collider. Partial decay rates are reported as functions of the recoil parameter \(w\) and three decay angles separately for electron and muon final states. We obtain \(|V_{cb}|\) using the Boyd-Grinstein-Lebed and Caprini-Lellouch-Neubert parametrizations, and find \(|V_{cb}|_\mathrm{BGL}=(40.57\pm 0.31 \pm 0.95\pm 0.58)\times 10^{-3}\) and \(|V_{cb}|_\mathrm{CLN}=(40.13 \pm 0.27 \pm 0.93\pm 0.58 )\times 10^{-3}\) with the uncertainties denoting statistical components, systematic components, and components from the lattice QCD input, respectively. The branching fraction is measured to be \({\cal B}(\overline{B}^0\to D^{*+}\ell^-\bar\nu_\ell)=(4.922 \pm 0.023 \pm 0.220)\%\). The ratio of branching fractions for electron and muon final states is found to be \(0.998 \pm 0.009 \pm 0.020\). In addition, we determine the forward-backward angular asymmetry and the \(D^{*+}\) longitudinal polarization fractions. All results are compatible with lepton-flavor universality in the Standard Model.
We present a measurement of time-dependent rate asymmetries in \(B^0\to \phi K^0_S\) decays to search for non-standard-model physics in \(b\to q \overline{q}s\) transitions. The data sample is ...collected with the Belle II detector at the SuperKEKB asymmetric-energy \(e^{+}e^{-}\) collider in 2019-2022 and contains \((387\pm 6)\times 10^6\) bottom-antibottom mesons from \(\Upsilon(4S)\) resonance decays. We reconstruct \(162\pm17\) signal events and extract the charge-parity (\(CP\)) violating parameters from a fit to the distribution of the proper-decay-time difference of the two \(B\) mesons. The measured direct and mixing-induced \(CP\) asymmetries are \(A=0.31\pm0.20\pm0.05\) and \(S=0.54\pm0.26^{+0.06}_{-0.08}\), respectively, where the first uncertainties are statistical and the second are systematic. The results are compatible with the \(CP\) asymmetries observed in \(b\to c\overline{c} s\) transitions.
We present the first comprehensive tests of light-lepton universality in the angular distributions of semileptonic \(B^0\)-meson decays to charged spin-1 charmed mesons. We measure five ...angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral \(B\) is fully reconstructed in \(\Upsilon\left(4S\right)\to{}B \overline{B}\) decays in data corresponding to \(189~\mathrm{fb}^{-1}\) integrated luminosity from electron-positron collisions collected with the Belle II detector. We find no significant deviation from the standard model expectations.
We measure \(C\!P\) asymmetries and branching-fraction ratios for \(B^\pm \to DK^\pm\) and \(D\pi^\pm\) decays with \(D\to K^0_{\rm S} K^\pm\pi^\mp\), where \(D\) is a superposition of \(D^0\) and ...\(\bar{D}^0\). We use the full data set of the Belle experiment, containing \(772\times 10^6~B\bar{B}\) pairs, and data from the Belle~II experiment, containing \(387\times 10^6~B\bar{B}\) pairs, both collected in electron-positron collisions at the \(\Upsilon(4S)\) resonance. Our results provide model-independent information on the unitarity triangle angle \(\phi_3\).
We report measurements of the branching fractions and direct \(\it{CP}\) asymmetries of the decays \(B^0 \to K^+ \pi^-\), \(B^+ \to K^+ \pi^0\), \(B^+ \to K^0 \pi^+\), and \(B^0 \to K^0 \pi^0\), and ...use these for testing the standard model through an isospin-based sum rule. In addition, we measure the branching fraction and direct \(\it{CP}\) asymmetry of the decay \(B^+ \to \pi^+\pi^0\) and the branching fraction of the decay \(B^0 \to \pi^+\pi^-\). The data are collected with the Belle II detector from \(e^+e^-\) collisions at the \(\Upsilon(4S)\) resonance produced by the SuperKEKB asymmetric-energy collider and contain \(387\times 10^6\) bottom-antibottom meson pairs. Signal yields are determined in two-dimensional fits to background-discriminating variables, and range from 500 to 3900 decays, depending on the channel. We obtain \(-0.03 \pm 0.13 \pm 0.04\) for the sum rule, in agreement with the standard model expectation of zero and with a precision comparable to the best existing determinations.
It is estimated that by the year 2050 one in five Americans will be 65 years or older. This mandates the growing need for clinical and basic research in the field of geriatric medicine to understand ...age-related maladies. The most prominent abnormality in renal function in the aging population is the inability to handle water, frequently resulting in hypo- or hyperosmolar states, and the associated electrolyte imbalances. During the past decade, thanks to the advent of powerful molecular techniques, rapid strides have been made in the approaches employed to understand and dissect the physiology of renal function in general and the urinary concentration mechanism in particular. Using an integrated approach of clinical observations, experimental model systems, molecular analysis, and functional genomics, a more comprehensive picture of the interplay of physiological systems in the genesis of urinary concentration defect in the elderly is beginning to emerge. Much remains to be deciphered regarding the complex interactions between the role of environment, genetics, diet, pharmacological agents and the general effects of aging on kidney function. The emerging importance of socio-economic and quality of life issues surrounding geriatric medicine encourage public and private support and funding for research in the area of age-related diseases, especially as they are related to the kidney.
We report results from a study of \(B^\pm \rightarrow DK^\pm\) decays followed by \(D\) decaying to \(CP\)~eigenstates, where \(D\) indicates a \(D^0\) or \(\bar{D}^{0}\) meson. These decays are ...sensitive to the Cabibbo-Kobayashi-Maskawa unitarity-triangle angle \(\phi_{3}\). The results are based on a combined analysis of the final data set of \(772 \times 10^6~B\bar{B}\) pairs collected by the Belle experiment and a data set of \(198 \times 10^6~B\bar{B}\) pairs collected by the Belle~II experiment, both in electron-positron collisions at the \(\Upsilon(4S)\) resonance. We measure the \(CP\) asymmetries to be \(\mathcal{ A}_{CP +} =~(+12.5 \pm 5.8 \pm 1.4)\% \) and \(\mathcal{ A}_{CP -} =~(-16.7 \pm 5.7 \pm 0.6)\%\), and the ratios of branching fractions to be \(\mathcal{ R}_{CP+}=~1.164 \pm 0.081 \pm 0.036 \) and \(\mathcal{ R}_{CP-} =~1.151 \pm 0.074 \pm 0.019\). The first contribution to the uncertainties is statistical, and the second is systematic. The asymmetries \(\mathcal{A}_{CP +}\) and \(\mathcal{A}_{CP -}\) have similar magnitudes and opposite signs; their difference corresponds to 3.5~standard deviations. From these values we calculate 68.3\% confidence intervals of (\(8.5^{\circ}<\phi_{3}<16.5^{\circ}\)) or (\(84.5^{\circ}<\phi_{3}<95.5^{\circ}\)) or (\(163.3^{\circ}<\phi_{3}<171.5^{\circ}\)) and \(0.321<r_{B}<0.465\).
Previous research has demonstrated that newborns are capable of preferentially responding to distinct tastes and food-related odors. However, whether infants are also capable of responding to ...distinct food textures has not been previously investigated. The present research determined whether food texture preferences differ during two developmental periods, infancy and toddlerhood, and whether experience with textures influenced infants' food preferences. In the present research, infants displayed more negative expressions, negative head movements and negative body movements when presented with more complex textures. In contrast, toddlers showed more positive head and body movements and more eagerness for complex textures. The data also suggest that experience with difficult-to-chew textures can facilitate a preference for a more complex texture. The present research adds to our understanding of early perceptual and discriminatory abilities and their development between infancy and early toddlerhood. In addition, the data highlight the need for food texture variation (within the range of the infants' feeding skills) to satisfy the infants' and toddlers' novelty preferences.
Grammatical Evolution Neural Networks (GENN) is a computational method designed to detect gene-gene interactions in genetic epidemiology, but has so far only been evaluated in situations with ...balanced numbers of cases and controls. Real data, however, rarely has such perfectly balanced classes. In the current study, we test the power of GENN to detect interactions in data with a range of class imbalance using two fitness functions (classification error and balanced error), as well as data re-sampling. We show that when using classification error, class imbalance greatly decreases the power of GENN. Re-sampling methods demonstrated improved power, but using balanced accuracy resulted in the highest power. Based on the results of this study, balanced error has replaced classification error in the GENN algorithm
Additional spin-0 particles appear in many extensions of the standard model. We search for long-lived spin-0 particles \(S\) in \(B\)-meson decays mediated by a \(b\to s\) quark transition in ...\(e^+e^-\) collisions at the \(\Upsilon(4S)\) resonance at the Belle II experiment. Based on a sample corresponding to an integrated luminosity of \(189 \mathrm{\,fb}^{-1}\), we observe no evidence for signal. We set model-independent upper limits on the product of branching fractions \(\mathrm{Br}(B^0\to K^*(892)^0(\to K^+\pi^-)S)\times \mathrm{Br}(S\to x^+x^-)\) and \(\mathrm{Br}(B^+\to K^+S)\times \mathrm{Br}(S\to x^+x^-)\), where \(x^+x^-\) indicates \(e^+e^-, \mu^+\mu^-, \pi^+\pi^-\), or \(K^+K^-\), as functions of \(S\) mass and lifetime at the level of \(10^{-7}\).
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