A
bstract
Charged-lepton-flavor-violation is predicted in several new physics scenarios. We update the analysis of
τ
lepton decays into a light charged lepton (
ℓ
=
e
±
or
μ
±
) and a vector meson (
...V
0
=
ρ
0
,
ϕ
,
ω
,
K
*0
, or
K
¯
*0
) using 980 fb
−
1
of data collected with the Belle detector at the KEKB collider. No significant excess of such signal events is observed, and thus 90% credibility level upper limits are set on the
τ
→
ℓV
0
branching fractions in the range of (1.7–4
.
3) × 10
−
8
. These limits are improved by 30% on average from the previous results.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract The production cross-sections of B mesons are measured in pp collisions at a centre-of-mass energy of 7 TeV, using ...data collected with the LHCb detector corresponding to a integrated luminosity of 0.36 fb^sup -1^. The B ^sup +^, B ^sup 0^ and ... mesons are reconstructed in the exclusive decays B ^sup +^ arrow right J/psiK ^sup +^, B ^sup 0^ arrow right J/psiK ^sup *0^ and ..., with J/psi arrow right mu ^sup +^ mu ^sup -^, K ^sup *0^ arrow right K ^sup +^pi^sup -^ and arrow right K ^sup +^ K ^sup -^. The differential cross-sections are measured as functions of B meson transverse momentum p ^sub T^ and rapidity y, in the range 0 < p ^sub T^ < 40 GeV/c and 2.0 < y < 4.5. The integrated cross-sections in the same p ^sub T^ and y ranges, including charge-conjugate states, are measured to be ...where the third uncertainty arises from the pre-existing branching fraction measurements. Figure not available: see fulltext.
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.
A
bstract
Using three- and four-body decays of
D
mesons produced in semileptonic
b
-hadron decays, precision measurements of
D
meson mass differences are made together with a measurement of the
D
0
...mass. The measurements are based on a dataset corresponding to an integrated luminosity of 1
.
0 fb
−1
collected in
pp
collisions at 7 TeV. Using the decay
D
0
→
K
+
K
−
K
−
π
+
, the
D
0
mass is measured to be
The mass differences
are measured using the
D
0
→
K
+
K
−
π
+
π
−
and
modes.
A
bstract
We present a search for the lepton-flavor-violating decays
B
s
0
→
ℓ
∓
τ
±
, where
ℓ
=
e, μ
, using the full data sample of 121 fb
−
1
collected at the Υ(5
S
) resonance with the Belle ...detector at the KEKB asymmetric-energy
e
+
e
−
collider. We use
B
s
0
B
¯
s
0
events in which one
B
s
0
meson is reconstructed in a semileptonic decay mode and the other in the signal mode. We find no evidence for
B
s
0
→ ℓ
∓
τ
±
decays and set upper limits on their branching fractions at 90% confidence level as
B
(
B
s
0
→ e
∓
τ
±
)
<
14
×
10
−
4
and
B
(
B
s
0
→ μ
∓
τ
±
)
<
7
.
3
×
10
−
4
. Our result represents the first upper limit on the
B
s
0
→ e
∓
τ
±
decay rate.
A
bstract
A study of
D
+
π
−
,
D
0
π
+
and
D
∗+
π
−
final states is performed using
pp
collision data, corresponding to an integrated luminosity of 1.0 fb
−1
, collected at a centre-of-mass energy of ...7 TeV with the LHCb detector. The
D
1
(2420)
0
resonance is observed in the
D
∗+
π
−
final state and the
$ D_2^{*}\left( {2460} \right) $
resonance is observed in the
D
+
π
−
,
D
0
π
+
and
D
∗+
π
−
final states. For both resonances, their properties and spin-parity assignments are obtained. In addition, two natural parity and two unnatural parity resonances are observed in the mass region between 2500 and 2800 MeV. Further structures in the region around 3000 MeV are observed in all the
D
∗+
π
−
,
D
+
π
−
and
D
0
π
+
final states.
The calibration and performance of the opposite-side flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been ...developed using simulated events and optimized and calibrated with
B
+
→
J
/
ψK
+
,
B
0
→
J
/
ψK
∗0
and
B
0
→
D
∗−
μ
+
ν
μ
decay modes with 0.37 fb
−1
of data collected in
pp
collisions at
during the 2011 physics run. The opposite-side tagging power is determined in the
B
+
→
J
/
ψK
+
channel to be (2.10±0.08±0.24) %, where the first uncertainty is statistical and the second is systematic.
A
bstract
We present a measurement of the Cabibbo-Kobayashi-Maskawa unitarity triangle angle
ϕ
3
(also known as
γ
) using a model-independent Dalitz plot analysis of
B
+
→
D
(
K
S
0
h
+
h
−
)
h
+
, ...where
D
is either a
D
0
or
D
¯
0
meson and
h
is either a
π
or
K
. This is the first measurement that simultaneously uses Belle and Belle II data, combining samples corresponding to integrated luminosities of 711 fb
−
1
and 128 fb
−
1
, respectively. All data were accumulated from energy-asymmetric
e
+
e
−
collisions at a centre-of-mass energy corresponding to the mass of the Υ(4
S
) resonance. We measure
ϕ
3
= (78
.
4 ± 11
.
4 ± 0
.
5 ± 1
.
0)°, where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is from the uncertainties on external measurements of the
D
-decay strong-phase parameters.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract A measurement of the Z(arrow right mu ^sup +^ mu ^sup -^) + jet production cross-section in pp collisions at a ...centre-of-mass energy ... = 7 TeV is presented. The analysis is based on an integrated luminosity of 1.0 fb^sup -1^ recorded by the LHCb experiment. Results are shown with two jet transverse momentum thresholds, 10 and 20 GeV, for both the overall cross-section within the fiducial volume, and for six differential cross-section measurements. The fiducial volume requires that both the jet and the muons from the Z boson decay are produced in the forward direction (2.0 < eta < 4.5). The results show good agreement with theoretical predictions at the second-order expansion in the coupling of the strong interaction. Figure not available: see fulltext.
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