Phys. Rev. D 109, 112015 (2024) We report on a search for a resonance $X$ decaying to a pair of muons in
$e^{+}e^{-}\rightarrow \mu^+ \mu^- X$ events in the 0.212-9.000 GeV/$c^{2}$
mass range, using ...178 fb$^{-1}$ of data collected by the BelleII experiment at
the SuperKEKB collider at a center of mass energy of 10.58 GeV. The analysis
probes two different models of $X$ beyond the standard model: a $Z^{\prime}$
vector boson in the $L_{\mu}-L_{\tau}$ model and a muonphilic scalar. We
observe no evidence for a signal and set exclusion limits at the 90$\%$
confidence level on the products of cross section and branching fraction for
these processes, ranging from 0.046 fb to 0.97 fb for the $L_{\mu}-L_{\tau}$
model and from 0.055 fb to 1.3 fb for the muonphilic scalar model. For masses
below 6 GeV/$c^{2}$, the corresponding constraints on the couplings of these
processes to the standard model range from 0.0008 to 0.039 for the
$L_{\mu}-L_{\tau}$ model and from 0.0018 to 0.040 for the muonphilic scalar
model. These are the first constraints on the muonphilic scalar from a
dedicated search.
Les tests d'écoute subjectifs permettent d'évaluer la fiabilité de reproduction des systèmes de codage audio (codecs). Le projet présenté ici vise à évaluer la possibilité d'utiliser les réactions ...physiologiques (activité électrodermale, cardiaque, musculaire et cérébrale) à la place d'une note donnée par l'auditeur, afin de caractériser la performance d'un codec. Ceci permettrait d'avoir une méthode d'évaluation plus proche de la perception réelle de qualité audio du sujet. Des tests d'écoute mettant en œuvre des dégradations audio bien connues en concours avec la mesure des réactions physiologiques ont été réalisés pour 4 auditeurs. L'analyse des résultats montre que certaines caractéristiques physiologiques permettent d'avoir une information fiable sur la qualité audio perçue, et ce de manière répétable pour près de 70% des signaux audio testés chez un sujet, et près de 60% des séquences audio testées chez tous les sujets. Ceci permet de postuler sur lâ faisabilité d'une telle méthode d'évaluation subjective des codecs audio. Mots-clés : test d'écoute subjectif, évaluation des codecs audio, mesures physiologiques, qualité audio perçue, conductance électrodermale, photoplethysmographie, électromyogramme, électroencéphalogramme
PRD 109, 111103 (2024) We measure the branching fraction of the decay $B^- \to D^0 \rho(770)^-$
using data collected with the Belle II detector. The data contain 387 million
$B\overline{B}$ pairs ...produced in $e^+e^-$ collisions at the $\Upsilon(4S)$
resonance. We reconstruct $8360\pm 180$ decays from an analysis of the
distributions of the $B^-$ energy and the $\rho(770)^-$ helicity angle. We
determine the branching fraction to be $(0.939 \pm 0.021\mathrm{(stat)} \pm
0.050\mathrm{(syst)})\%$, in agreement with previous results. Our measurement
improves the relative precision of the world average by more than a factor of
two.
We describe a measurement of charge-parity ($CP$) violation asymmetries in
$B^0\to\eta'K^0_S$ decays using Belle II data. We consider
$\eta'\to\eta(\to\gamma\gamma)\pi^+\pi^-$ and
...$\eta'\to\rho(\to\pi^+\pi^-)\gamma$ decays. The data were collected at the
SuperKEKB asymmetric-energy $e^+e^-$ collider between the years 2019 and 2022,
and contain $(387\pm 6) \times 10^6$ bottom-antibottom meson pairs. We
reconstruct $829\pm35$ signal decays and extract the $CP$ violating parameters
from a fit to the distribution of the proper-decay-time difference between the
two $B$ mesons. The measured direct and mixing-induced $CP$ asymmetries are
$\text{C}_{\eta'K^0_S} = -0.19 \pm 0.08 \pm 0.03 $ and $\text{S}_{\eta'K^0_S} =
+0.67 \pm 0.10 \pm 0.04 $, respectively, where the first uncertainties are
statistical and the second are systematic. These results are in agreement with
current world averages and standard model predictions.
To assess the normality of the cutaneous blood flow reserve (CR).
To explore the feasibility and reproducibility of laser-Doppler flowmetry for CR measurement, we prospectively measured CR in 17 ...healthy subjects on the dorsum of the foot and pulp of the big toe. CR was defined as the sum of the venoarteriolar reflex (VAR), i.e. postural vasoconstriction, and postischemic reactive vasodilation (H), expressed as % of the resting supine flux and assessed by using laser-Doppler flowmetry.
For the dorsal foot, VAR%+/-SEM was 61+/-14, H%, 752.5+/-214 and CR, 813.5+/-217. On the pulp of the big toe, VAR% was 61.6+/-4.7, H%, 588.2+/-174 and CR, 649.9+/-176. CR measurement variability was assessed by calculating the inter-individual coefficient of variation of CR, which was 1.1 for both the dorsal foot and pulp of the big toe. Reproducibility was assessed by calculating the CR intraclass correlation coefficient, which was 0.49 for the dorsal foot and 0.64 for the pulp of the big toe.
The CR is proposed as a new parameter for assessing the microvascular integrity and contractile reserve of the skin. Laser-Doppler flowmetry is suitable for this non-invasive evaluation. The method displayed large variability, and its reproducibility varied from moderate for the dorsal foot, to substantial for the toe. Further studies are necessary to demonstrate its clinical usefulness.
Silicon photonics technological platforms are meant to generate derivative products and concurrently to benefit from the main advantages associated with CMOS platforms namely: high yield, system ...robustness, product reliability and large volume, low cost production. Nevertheless, a simultaneous innovative approach is to analogously take advantage from state-of-the-art fabrication methods and tools available in CMOS to develop new solutions and propose better performing devices to the platform.
Phys. Rev. D 109, 112006 (2024) 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 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.
Une analyse du contenu des messages inscrits sur les registres de condoléances à la mort des présidents de la République en France doit nécessairement considérer que ces messages sont des opinions ...politiques et qu’ils s’inscrivent dans un échange dont dépend le sens de l’hommage adressé au défunt. L’étude de ces deux présupposés amène au contraire à proposer une définition plurivoque de l’activité de signature d’un registre, activité qui tolère des investissements et des tactiques très différenciés.
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