We measure the tau-to-light-lepton ratio of inclusive B -meson branching fractions R ( X τ / ℓ ) ≡ B ( B → X τ ν ) / B ( B → X ℓ ν ) , where ℓ indicates an electron or muon, and thereby test the ...universality of charged-current weak interactions. We select events that have one fully reconstructed B meson and a charged lepton candidate from 189 fb − 1 of electron-positron collision data collected with the Belle II detector. We find R ( X τ / ℓ ) = 0.228 ± 0.016 ( stat ) ± 0.036 ( syst ) , in agreement with standard-model expectations. This is the first direct measurement of R ( X τ / ℓ ) . Published by the American Physical Society 2024
We report the first evidence for isospin violation in B→K^{*}γ and the first measurement of the difference of CP asymmetries between B^{+}→K^{*+}γ and B^{0}→K^{*0}γ. This analysis is based on the ...data sample containing 772×10^{6}BBover ¯ pairs that was collected with the Belle detector at the KEKB energy-asymmetric e^{+}e^{-} collider. We find evidence for the isospin violation with a significance of 3.1σ, Δ_{0+}=+6.2±1.5(stat)±0.6(syst)±1.2(f_{+-}/f_{00})%, where the third uncertainty is due to the uncertainty on the fraction of B^{+}B^{-} to B^{0}Bover ¯^{0} production in ϒ(4S) decays. The measured value is consistent with predictions of the standard model. The result for the difference of CP asymmetries is ΔA_{CP}=+2.4±2.8(stat)±0.5(syst)%, consistent with zero. The measured branching fractions and CP asymmetries for charged and neutral B meson decays are the most precise to date. We also calculate the ratio of branching fractions of B^{0}→K^{*0}γ to B_{s}^{0}→ϕγ.
We report a study of the charmless hadronic decay of the charged B meson to the three-body final state K+K−π+. The results are based on a data sample that contains 772×106 BB¯ pairs collected at the ...ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The measured inclusive branching fraction and direct CP asymmetry are (5.38±0.40±0.35)×10−6 and −0.170±0.073±0.017, respectively, where the first uncertainties are statistical and the second are systematic. The K+K− invariant mass distribution of the signal candidates shows an excess in the region below 1.5 GeV/c2, which is consistent with the previous studies from BABAR and LHCb. In addition, strong evidence of a large direct CP asymmetry is found in the low K+K− invariant-mass region.
A
bstract
We report results from a study of
B
±
→ DK
±
decays followed by
D
decaying to the
CP
-even final state
K
+
K
−
and CP-odd final state
K
S
0
π
0
, where
D
is an admixture of
D
0
and
D
¯
0
...states. These decays are sensitive to the Cabibbo-Kobayashi-Maskawa unitarity-triangle angle
ϕ
3
. The results are based on a combined analysis of the final data set of 772
×
10
6
B
B
¯
pairs collected by the Belle experiment and a data set of 198
×
10
6
B
B
¯
pairs collected by the Belle II experiment, both in electron-positron collisions at the Υ(4
S
) resonance. We measure the CP asymmetries to be
A
CP
+
= (+12.5
±
5.8
±
1.4)% and
A
CP−
= (
−
16.7
±
5.7
±
0.6)%, and the ratios of branching fractions to be
R
CP
+
= 1.164
±
0.081
±
0.036 and
R
CP−
= 1.151
±
0.074
±
0.019. The first contribution to the uncertainties is statistical, and the second is systematic. The asymmetries
A
CP
+
and
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
°
<
ϕ
3
< 16.5
°
) or (84.5
°
<
ϕ
3
< 95.5
°
) or (163.3
°
<
ϕ
3
< 171.5
°
) and 0.321 <
r
B
< 0.465.
HEIBL C., TROMMET V., BURGSTALLER S., MAYRBAEURL B., BALDINGER C., KOPLMÜLLER R., KÜHR T., WIMMER L. & THALER J. (2010) European Journal of Cancer Care19, 676–681
Complications associated with the ...use of Port‐a‐Caths in patients with malignant or haematological disease: a single‐centre prospective analysis
Totally implantable central venous catheters are widely used in the management of patients with haematological or malignant disease. This paper investigates device‐related complications and compares it with the literature. A total of 143 Port‐a‐Caths (PaCs) were implanted in 140 patients at a single centre during 2004 and followed until March 2005. Indication for implantation was mainly administration of chemotherapy. High standards of care were applied through intensive training of staff. Complications were registered prospectively and cross‐checked with the medical records at the end of the observational period. The ports were in place for a total of 29 107 days (mean 204, range 3–443 days per port). A total of 25 complications were recorded. These included 13 infections 9.1% with 5 cutaneous (3.5%) and 8 systemic (5.6%) infections, one deep vein thrombosis (0.7%). In 6 patients (4.2%) the device had to be removed because of complications. No device‐related death was observed. The use of totally implantable central venous catheters for treating haemoto‐oncological patients is safe. The need for device removal due to complications was particularly low in this analysis as compared with the literature.
We present results from a study of X(3872)→ππJ/ψ decays produced via exclusive B→KX(3872) decays. We determine the mass to be MX(3872)=(3871.85±0.27(stat)±0.19(syst)) MeV, a 90% confidence level ...upper limit on the natural width of ΓX(3872)<1.2 MeV, the product branching fraction B(B+→K+X(3872))×B(X(3872)→π+π-J/ψ)=(8.63±0.82(stat)±0.52(syst))×10-6, and a ratio of branching fractions B(B0→K0X(3872))/B(B+→K+X(3872))=0.50±0.14(stat)±0.04(syst). The difference in mass between the X(3872)→π+π-J/ψ signals in B+ and B0 decays is ΔMX(3872)=(-0.71±0.96(stat)±0.19(syst)) MeV. A search for a charged partner of the X(3872) in the decays B0→K-X+ or B+→K0X+, X+→π+π0J/ψ resulted in upper limits on the product branching fractions for these processes that are well below expectations for the case that the X(3872) is the neutral member of an isospin triplet. In addition, we examine possible JPC quantum number assignments for the X(3872) based on comparisons of angular correlations between final state particles in X(3872)→π+π-J/ψ decays with simulated data for JPC values of 1++ and 2-+. We examine the influence of ρ-ω interference in the M(π+π-) spectrum. The analysis is based on a 711 fb-1 data sample that contains 772×106 BB meson pairs collected at the Υ(4S) resonance in the Belle detector at the KEKB e+e- collider.
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