Phys. Rev. Lett. 130, 031901 (2023) We present the study of $\bar{B}^{0} \to \Sigma_{c}(2455)^{0,++} \pi^{\pm}
\bar{p}$ decays based on $772\times 10^{6}$ $B\bar{B}$ events collected with
the Belle ...detector at the KEKB asymmetric-energy $e^+e^-$ collider. The
$\Sigma_{c}(2455)^{0,++} $ candidates are reconstructed via their decay to
$\Lambda_{c}^{+} \pi^{\mp}$ and $\Lambda_{c}^{+}$ decays to
$pK^{-}\pi^{+},~pK_{S}^{0},$ and $\Lambda\pi^{+}$ final states. The
corresponding branching fractions are measured to be ${\cal B}(\bar{B}^{0} \to
\Sigma_{c}(2455)^{0} \pi^{+} \bar{p}) = (1.09 \pm 0.06 \pm 0.07)\times10^{-4}$
and ${\cal B}(\bar{B}^{0} \to \Sigma_{c}(2455)^{++} \pi^{-} \bar{p}) = (1.84\pm
0.11 \pm 0.12)\times 10^{-4}$, which are consistent with the world average
values with improved precision. A new structure is found in the
$M_{\Sigma_{c}(2455)^{0,++}\pi^{\pm}}$ spectrum with a significance of
$4.2\sigma$ including systematic uncertainty. The structure is possibly an
excited $\Lambda_{c}^{+}$ and is tentatively named $\Lambda_{c}(2910)^{+}$. Its
mass and width are measured to be $(2913.8 \pm 5.6 \pm 3.8)$ MeV/$c^{2}$ and
$(51.8\pm20.0 \pm 18.8)$ MeV, respectively. The products of branching fractions
for the $\Lambda_{c}(2910)^{+}$ are measured to be ${\cal B}(\bar{B}^{0} \to
\Lambda_{c}(2910)^{+}\bar{p})\times{\cal B}(\Lambda_{c}(2910)^{+} \to
\Sigma_{c}(2455)^{0}\pi^{+}) = (9.5 \pm 3.6 \pm 1.6)\times 10^{-6}$ and ${\cal
B}(\bar{B}^{0} \to \Lambda_{c} (2910)^{+}\bar{p})\times {\cal
B}(\Lambda_{c}(2910)^{+} \to \Sigma_{c}(2455)^{++}\pi^{-}) = (1.24 \pm 0.35 \pm
0.10)\times 10^{-5}$. Here, the first and second uncertainties are statistical
and systematic, respectively.
From e(+)e(-) collision data acquired with the CLEO detector at the Cornell Electron Storage Ring, we observe the non-DD(_) decay Psi(3770))-->gammachi(c1) with a statistical significance of 6.6 ...standard deviations, using the two-photon cascades to J/Psi and J/Psi-->l(+)l(-). We determine sigma(e(=)e(-)-->Psi(3770))xBeta(Psi(3770)-->gammachi(c1))=(18.0 +/- 3.3 +/- 2.5) pb and branching fraction Beta(Psi(3770)-->gammachi(c1)=(2.8 +/- 0.5+/-0.4) x 10(-3). We set 90% C.L. upper limits for the transition to chi(c2) (chi(c0)): sigma x Beta<5.7 pb (<282 pb) and Beta<0.9 x 10(-3) (<44 x 10(-3)). We also determine Gamma(Psi(3770)gammachi(c1))/Gamma(Psi(3770)-->pi(+)pi(-)J/Psi)=1.5 +/- 0.3 +/- 0.3 (>1.0 at 90% C.L.), which bears upon the interpretation of X(3872).
We present a measurement of the $B^{0} \rightarrow D^{*-} \ell^{+}
\nu_{\ell}$ ($\ell=e,\mu$) branching ratio and of the CKM parameter $|V_{cb}|$
using signal decays accompanied by a fully ...reconstructed $B$ meson. The Belle
II data set of electron-positron collisions at the $\Upsilon(4S)$ resonance,
corresponding to 189.3$\,$fb$^{-1}$ of integrated luminosity, is analyzed. With
the Caprini-Lellouch-Neubert form factor parameterization, the parameters
$\eta_{\rm EW} F(1) |V_{cb}|$ and $\rho^{2}$ are extracted, where $\eta_{\rm
EW}$ is an electroweak correction, $F(1)$ is a normalization factor and
$\rho^{2}$ is a form factor shape parameter. We reconstruct 516 signal decays
and thereby obtain $\mathcal{B} (B^{0} \rightarrow D^{*-} \ell^{+} \nu_{\ell} )
= \left(5.27 \pm 0.22~\rm{\left(stat\right)} \pm
0.38~\rm{\left(syst\right)}\right) \%$, $\eta_{EW} F(1) |V_{cb}| \times 10^{3}
= 34.6 \pm 1.8~\rm{\left(stat\right)} \pm 1.7~\rm{\left(syst\right)}$, and
$\rho^{2} = 0.94 \pm 0.18~\rm{\left(stat\right)} \pm
0.11~\rm{\left(syst\right)}$.
We study the decay $B^{+} \to K^+ K^- \pi^+$ and investigate the angular
distribution of $K^{+}K^{-}$ pairs with invariant mass below $1.1$ GeV/$c^2$.
This region exhibits both a strong enhancement ...in signal and very large direct
$CP$ violation. We construct a coherent sum model for the angular distribution
of $S$- and $P$-wave, and report the ratio of their amplitudes, the relative
phase and the forward-backward asymmetry. We also report absolute differential
branching fractions and direct $CP$ asymmetry for the decay in bins of
$M_{K^+K^-}$ and the differential branching fractions in bins of
$M_{K^+\pi^-}$. The results are based on a data sample that contains
$772\times10^6$ $B \bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance
with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. The
measured overall branching fraction and the direct $CP$ asymmetry are
$(5.38\pm0.40\pm0.35)\times 10^{-6}$ and $-0.170\pm0.073\pm0.017$,
respectively, where the first uncertainties are statistical and the second are
systematic.
Physical Review Letters 130, 091902 (2023) We study the processes $e^+e^-\to\omega\chi_{bJ}(1P)$ ($J$ = 0, 1, or 2)
using samples at center-of-mass energies $\sqrt{s}$ = 10.701, 10.745, and
10.805 ...GeV, corresponding to 1.6, 9.8, and 4.7 fb$^{-1}$ of integrated
luminosity, respectively. These data were collected with the Belle II detector
during special operations of the SuperKEKB collider above the $\Upsilon(4S)$
resonance. We report the first observation of $\omega\chi_{bJ}(1P)$ signals at
$\sqrt{s}$ = 10.745 GeV. By combining Belle II data with Belle results at
$\sqrt{s}$ = 10.867 GeV, we find energy dependencies of the Born cross sections
for $e^+e^-\to \omega\chi_{b1,b2}(1P)$ to be consistent with the shape of the
$\Upsilon(10753)$ state. These data indicate that the internal structures of
the $\Upsilon(10753)$ and $\Upsilon(10860)$ states may differ. Including data
at $\sqrt{s}$ = 10.653 GeV, we also search for the bottomonium equivalent of
the $X(3872)$ state decaying into $\omega\Upsilon(1S)$. No significant signal
is observed for masses between 10.45 and 10.65 GeV/$c^2$.
Climate-change refugia in boreal North America Stralberg, Diana; Arseneault, Dominique; Baltzer, Jennifer L ...
Frontiers in ecology and the environment,
06/2020, Letnik:
18, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The vast boreal biome plays an important role in the global carbon cycle but is experiencing particularly rapid climate warming, threatening the integrity of valued ecosystems and their component ...species. We developed a framework and taxonomy to identify climate-change refugia potential in the North American boreal region, summarizing current knowledge regarding mechanisms, geographic distribution, and landscape indicators. While “terrain-mediated” refugia will mostly be limited to coastal and mountain regions, the ecological inertia (resistance to external fluctuations) contained in some boreal ecosystems may provide more extensive buffering against climate change, resulting in “ecosystem-protected” refugia. A notable example is boreal peatlands, which can retain high surface soil moisture and water tables even in the face of drought. Refugia from wildfire are also especially important in the boreal region, which is characterized by active disturbance regimes. Our framework will help identify areas of high refugia potential, and inform ecosystem management and conservation planning in light of climate change.
We measure the cross section for e+e- -->psi(3770) -->hadrons at Ec.m.=3773 MeV to be (6.38+/-0.08(+0.41)(-0.30) nb using the CLEO detector at the CESR e+e- collider. The difference between this and ...the e+e- -->psi(3770) -->DD cross section at the same energy is found to be (-0.01+/-0.08(+0.41)(-0.30) nb. With the observed total cross section, we extract Gamma(ee)(psi(3770))=(0.204+/-0.003(+0.041)(-0.027) keV. Uncertainties shown are statistical and systematic, respectively.
Phys. Rev. D 107, L031103 (2023) We report on a measurement of the $\Omega_c^0$ lifetime using $\Omega_c^0 \to
\Omega^-\pi^+$ decays reconstructed in $e^+e^-\to c\bar{c}$ data collected by
the Belle ...II experiment and corresponding to $207~{\rm fb^{-1}}$ of integrated
luminosity. The result, $\rm\tau(\Omega_c^0)=243\pm48( stat)\pm11(syst)~fs$,
agrees with recent measurements indicating that the $\Omega_c^0$ is not the
shortest-lived weakly decaying charmed baryon.
Using 420 pb(-1) of data collected on the upsilon(5S) resonance with the CLEO III detector, we reconstruct B mesons in 25 exclusive decay channels to measure or set upper limits on the decay rate of ...upsilon(5S) into B meson final states. We measure the inclusive B cross section to be sigma(upsilon(5S) --> BB(X)) = (0.177 +/- 0.030 +/- 0.016) nb and make the first measurements of the production rates of sigma(upsilon(5S) --> B*B*) = (0.131 +/- 0.025 +/- 0.014) nb and sigma(upsilon(5S) --> BB*) = (0.043 +/- 0.016 +/- 0.006) nb, respectively. We set 90% confidence level limits of sigma(upsilon(5S) -->BB) < 0.038 nb, sigma(upsilon(5S) --> B(*)B(*)pi) < 0.055 nb and sigma(upsilon(5S) --> BBpipi) < 0.024 nb. We also extract the most precise value of the B(s)* mass to date, M(B(s)*) = (5411.7 +/- 1.6 +/- 0.6) MeV/c2.
Phys. Rev. D 107, 033003 (2023) We present measurements of the branching fractions for the singly
Cabibbo-suppressed decays $D^+\to K^{+}K^{-}\pi^{+}\pi^{0}$ and $D_s^{+}\to
...K^{+}\pi^{-}\pi^{+}\pi^{0}$, and the doubly Cabibbo-suppressed decay $D^{+}\to
K^{+}\pi^{-}\pi^{+}\pi^{0}$, based on 980 ${\rm fb}^{-1}$ of data recorded by
the Belle experiment at the KEKB $e^{+}e^{-}$ collider. We measure these modes
relative to the Cabibbo-favored modes $D^{+}\to K^{-}\pi^{+}\pi^{+}\pi^{0}$ and
$D_s^{+}\to K^{+}K^{-}\pi^{+}\pi^{0}$. Our results for the ratios of branching
fractions are $B(D^{+}\to K^{+}K^{-}\pi^{+}\pi^{0})/B(D^{+}\to
K^{-}\pi^{+}\pi^{+}\pi^{0}) = (11.32 \pm 0.13 \pm 0.26)\%$, $B(D^{+}\to
K^{+}\pi^{-}\pi^{+}\pi^{0})/B(D^{+}\to K^{-}\pi^{+}\pi^{+}\pi^{0}) = (1.68 \pm
0.11\pm 0.03)\%$, and $B(D_s^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0})/B(D_s^{+}\to
K^{+}K^{-}\pi^{+}\pi^{0}) = (17.13 \pm 0.62 \pm 0.51)\%$, where the
uncertainties are statistical and systematic, respectively. The second value
corresponds to $(5.83\pm 0.42)\times\tan^4\theta_C$, where $\theta_C$ is the
Cabibbo angle; this value is larger than other measured ratios of branching
fractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored
decay. Multiplying these results by world average values for $B(D^{+}\to
K^{-}\pi^{+}\pi^{+}\pi^{0})$ and $B(D_s^{+}\to K^{+}K^{-}\pi^{+}\pi^{0})$
yields $B(D^{+}\to K^{+}K^{-}\pi^{+}\pi^{0})= (7.08\pm 0.08\pm 0.16\pm
0.20)\times10^{-3}$, $B(D^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0})= (1.05\pm 0.07\pm
0.02\pm 0.03)\times10^{-3}$, and $B(D_s^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0}) =
(9.44\pm 0.34\pm 0.28\pm 0.32)\times10^{-3}$, where the third uncertainty is
due to the branching fraction of the normalization mode. The first two results
are consistent with, but more precise than, the current world averages. The
last result is the first measurement of this branching fraction.
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