A
bstract
We present measurements of the branching fractions for the decays
B
→
Kμ
+
μ
−
and
B
→
Ke
+
e
−
, and their ratio (
R
K
), using a data sample of 711 fb
−
1
that contains 772 × 10
6
B
B
¯
...events. The data were collected at the ϒ(4
S
) resonance with the Belle detector at the KEKB asymmetric-energy
e
+
e
−
collider. The ratio
R
K
is measured in five bins of dilepton invariant-mass-squared (
q
2
):
q
2
∈ (0
.
1
,
4
.
0)
,
(4
.
00
,
8
.
12)
,
(1
.
0
,
6
.
0), (10
.
2
,
12
.
8) and (
>
14
.
18) GeV
2
/c
4
, along with the whole
q
2
region. The
R
K
value for
q
2
∈ (1
.
0
,
6
.
0) GeV
2
/c
4
is
1.03
−
0.24
+
0.28
± 0
.
01. The first and second uncertainties listed are statistical and systematic, respectively. All results for
R
K
are consistent with Standard Model predictions. We also measure
CP
-averaged isospin asymmetries in the same
q
2
bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the
q
2
∈ (1
.
0
,
6
.
0) GeV
2
/c
4
bin in the mode with muon final states. The measured differential branching fractions,
d
ℬ
/dq
2
, are consistent with theoretical predictions for charged
B
decays, while the corresponding values are below the expectations for neutral
B
decays. We have also searched for lepton-flavor-violating
B
→
Kμ
±
e
∓
decays and set 90% confidence-level upper limits on the branching fraction in the range of 10
−
8
for
B
+
→
K
+
μ
±
e
∓
, and
B
0
→
K
0
μ
±
e
∓
modes.
We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| from B0→D*−ℓ+νℓ decays, reconstructed with the full Belle data set of 711 fb−1 integrated luminosity. Two form ...factor parametrizations, originally conceived by the Caprini-Lellouch-Neubert (CLN) and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product F(1)ηEW|Vcb| and the decay form factors, where F(1) is the normalization factor and ηEW is a small electroweak correction. In the CLN parametrization we find F(1)ηEW|Vcb|=(35.06±0.15±0.56)×10−3, ρ2=1.106±0.031±0.007, R1(1)=1.229±0.028±0.009, R2(1)=0.852±0.021±0.006. For the BGL parametrization we obtain F(1)ηEW|Vcb|=(34.93±0.23±0.59)×10−3, which is consistent with the world average when correcting for F(1)ηEW. The branching fraction of B0→D*−ℓ+νℓ is measured to be B(B0→D*−ℓ+νℓ)=(4.90±0.02±0.16)%. We also present a new test of lepton flavor universality violation in semileptonic B decays, B(B0→D*−e+ν)B(B0→D*−μ+ν)=1.01±0.01±0.03. The errors quoted correspond to the statistical and systematic uncertainties, respectively. This is the most precise measurement of F(1)ηEW|Vcb| and form factors to date and the first experimental study of the BGL form factor parametrization in an experimental measurement.
A
bstract
Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays
τ
±
→
ℓ
±
γ
(
ℓ
=
e, μ
) are ...predicted to have a sizeable probability, making them particularly interesting channels to search at various experiments. An updated search via
τ
±
→
ℓ
±
γ
using full data of the Belle experiment, corresponding to an integrated luminosity of 988 fb
−
1
, is reported for charged lepton flavor violation. No significant excess over background predictions from the Standard Model is observed, and the upper limits on the branching fractions,
B
(
τ
±
→
μ
±
γ
) ≤ 4
.
2 × 10
−
8
and
B
(
τ
±
→
e
±
γ
) ≤ 5
.
6 × 10
−
8
, are set at 90% confidence level.
This paper investigates the perception of security risk and causes of crimes in gated and non-gated communities in Lahore, Pakistan. Due to increasing rate of crimes in the city, the trend and demand ...of gated communities are rising. People living in non-gated communities have installed barriers and gates in through streets to prevent crimes. The data was collected by conducting face to face interviews with the residents of a gated and non-gated community in Lahore, concerned officials of police stations and Lahore Development Authority using structured questionnaires. Results of data analysis revealed that the residents with high-income experience fewer crimes than the residents with low/middle income, since they are more vulnerable to crimes. The perception of insecurity among the residents is directly proportional to the frequency of crimes in that community. Moreover, residents of gated community are more satisfied with the safety and security measures. Several through streets in each block of non-gated community are facilitating crimes. This shows that the layout plan of residential community also plays an important role in facilitating/reducing the crime. The number of reported crimes in the non-gated community is 25 times higher than the reported crimes in the gated community. Un-registered tenants are also found to be indulged in criminal activities in such communities. Recommendations are made to transform both types of communities and plan future neighbourhoods as more safer places for living.
A
bstract
We present a search for the charged lepton-flavor-violating decays ϒ(1
S
)
→
ℓ
±
ℓ
′
∓
and radiative charged lepton-flavour-violating decays ϒ(1
S
)
→ γ
ℓ
±
ℓ
′
∓
ℓ
,
ℓ
′ =
e, μ, τ
using ...the 158 million ϒ(2
S
) sample collected by the Belle detector at the KEKB collider. This search uses ϒ(1
S
) mesons produced in ϒ(2
S
)
→ π
+
π
−
ϒ(1
S
) transitions. We do not find any significant signal, so we provide upper limits on the branching fractions at the 90% confidence level.
Addition chloro acetyl isothiocyanate (C3H2ClNOS) with 3-Aminoaceto phenone (C8H9NO) to prepare a fresh Ligand N-(3-acetyl phenyl carbamothioyl)-2-chloroacetamide(L). The ligand (L) behaves as ...bidentate coordinating through O and S donor with metal ions, the general formula of all complexes M(L)2(Cl)2(M+2 = Manganese(II), Cobalt(II), Cadmium(II) and Mercury(II)). Compounds were investigation by Proton-1, Carbon -13 NMR spectra (ligand (L) only), Element Microanalysis for C, N, H, O, S, Fourier-transform infrared, UV visible, Conductance, Magnetic susceptibility and Atomic Absorption (A.A). Based on spectral data, complexes appear octahedral geometry. The anti-bacterial activity of the complexes against two type of bacterial was higher than for free ligand.
A
bstract
We present the analysis of two-particle angular correlations using coordinate systems defined with the conventional beam axis and the event thrust axis. We propose the latter as a good ...representation for the correlation structure interpretation in the
e
+
e
−
collision system. The
e
+
e
−
collisions to hadronic final states at center-of-mass energies of
s
= 10
.
52 GeV and 10.58 GeV are recorded by the Belle detector at KEKB. In this paper, results on the first dataset are supplementary to the previous Belle publication
1
. At the same time, the latter is the first two-particle correlation measurement at collision energy on the
Υ
(4
S
) resonance and is sensitive to its decay products. Measurements are reported as a function of the charged-particle multiplicity. Finally, a qualitative understanding of the correlation structure is discussed using a combination of Monte Carlo simulations and experimental data.
A
bstract
We report the measurement of the two-photon decay width of
χ
c
2
(1
P
) in two-photon processes at the Belle experiment. We analyze the process
γγ
→
χ
c
2
(1
P
) →
J/ψγ
,
J/ψ
→
ℓ
+
ℓ
−
(
ℓ
...=
e
or
μ
) using a data sample of 971 fb
−
1
collected with the Belle detector at the KEKB
e
+
e
−
collider. In this analysis, the product of the two-photon decay width of
χ
c
2
(1
P
) and the branching fraction is determined to be
Γ
γγ
χ
c
2
1
P
B
χ
c
2
1
P
→
J
/
ψγ
B
J
/
ψ
→
ℓ
+
ℓ
−
=
14.8
±
0.3
stat
.
±
0.7
syst
.
eV, which corresponds to Γ
γγ
(
χ
c
2
(1
P
)) = 653
±
13(stat.)
±
31(syst.)
±
17(B.R.) eV, where the third uncertainty is from
B
(
χ
c
2
(1
P
)
→ J/ψγ
) and
B
(
J/ψ → ℓ
+
ℓ
−
).
Slow control of the Belle II Aerogel Ring Imaging detector Pestotnik, R.; Adachi, I.; Adamczyk, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2023, Volume:
1056
Journal Article
Peer reviewed
Open access
Since 2018, an Proximity Focusing Aerogel Ring Imaging Detector (ARICH) efficiently separates hadrons in the forward end-cap of the Belle II spectrometer. Cherenkov photons emitted in the ...double-layer aerogel radiator are expanded in 16-cm space and detected on the photon detector, which consists of 420 hybrid avalanche photodiodes and rear readout electronics operating in threshold mode. Each of the sensors requires six different high voltages and a supply of four low voltages for the electronics. Because of the power dissipation, the system also includes a cooling system in which cold water circulates through the Al tubes thermally connected to the readout electronics. Reliable control of supply voltages and monitoring of environmental data and sensor status ensure stable operation of the ARICH detector and early response to sudden changes in current, single event disturbances, overheating, and other faults. In this paper, we introduce the ARICH’s slow control system and the data quality monitor used to track performance.
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