118,228 research outputs found
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
No full textAn analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
New Liu Estimators for the Poisson Regression Model: Method and Application
No full textA new shrinkage estimator for the Poisson model is introduced in this paper. This method is a generalization of the Liu (1993) estimator originally developed for the linear regression model and will be generalised here to be used instead of the classical maximum likelihood (ML) method in the presence of multicollinearity since the mean squared error (MSE) of ML becomes inflated in that situation. Furthermore, this paper derives the optimal value of the shrinkage parameter and based on this value some methods of how the shrinkage parameter should be estimated are suggested. Using Monte Carlo simulation where the MSE and mean absolute error (MAE) are calculated it is shown that when the Liu estimator is applied with these proposed estimators of the shrinkage parameter it always outperforms the ML. Finally, an empirical application has been considered to illustrate the usefulness of the new Liu estimators.Estimation; MSE; MAE; Multicollinearity; Poisson; Liu; Simulation
On the long distance contribution to the B-s -> gamma gamma decay in the effective Lagrangian approach
No full textWe re-estimate the decay branching ratio of B-s --> 2 gamma through D-s(+) D-s(-) and D-s* (+) D-s* (-) intermediate states, in the effective Lagrangian approach. We find that the branching ratio does not exceed a few times 10(-7), contrary to the result recently claimed in the literature. (C) 1999 Published by Elsevier Science B.V. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000082448700019&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)4ARTICLE3295-29846
Observations of Bºs→ψ(2S)η and Bº(s)→ψ(2S)π+π- decays
No full textFirst observations of the B0s
→ψ(2S)η, B0 →ψ(2S)π
+
π
− and B0s
→ψ(2S)π
+
π
− decays are made
using a dataset corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment in
proton–proton collisions at a centre-of-mass energy of
√
s = 7 TeV. The ratios of the branching fractions
of each of the ψ(2S) modes with respect to the corresponding J/ψ decays are
B(B0s
→ψ(2S)η)
÷
B(B0s
→J/ψη)
= 0.83± 0.14 (stat)±0.12 (syst) ±0.02 (B),
;
B(B0→ψ(2S)π
+
π
−
)
÷
B(B0→J/ψπ
+
π
−
)
= 0.56± 0.07 (stat)±0.05 (syst)± 0.01 (B),
;
B(B0s
→ψ(2S)π
+
π
−
)
÷
B(B0s
→J/ψπ
+
π
−
)
= 0.34± 0.04 (stat)±0.03 (syst)± 0.01 (B),
where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the J/ψ
and ψ(2S) meson decays
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
A Subband-Selective Broadband GSC with Cosine-Modulated Blocking Matrix
No full textIn this paper, a novel subband-selective generalized sidelobe canceller (GSC) for partially adaptive broadband beamforming is proposed. The columns of the blocking matrix are derived from a prototype vector by cosine-modulation, and the broadside constraint is incorporated by imposing zeros on the prototype vector appropriately. These columns constitute a series of bandpass filters, which select signals with specific angles of arrival and frequencies. This results in highpass-type bandlimited spectra of the blocking matrix outputs, which is further exploited by subbands decomposition and suitably discarding the low-pass subbands prior to running independent unconstrained adaptive filters in each non-redundant subband. By these steps, the computational complexity of a GSC implementation is greatly reduced compared to fully adaptive GSC schemes, while performance is comparable or even enhanced due to subband decorrelation in both spatial and temporal domains
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Ellipsoidisporodochium photiniae S. B. Liu, J. W. Xia & X. G. Zhang 2022, sp. nov.
No full textEllipsoidisporodochium photiniae S.B. Liu, J.W. Xia & X.G. Zhang, sp. nov. Fig. 2 MycoBank: 842209 Etymology: The specific epithet refers to the genus of the host plant Photinia serratifolia. Description: Asscociated with leaf spot on Photinia serratifolia. Conidiomata sporodochial, appeared within 14 days or longer, formed on agar surface, globose to subglobose, pale bluish green in the center, with a layer of transparent conidia on the outside. Sporodochial conidiophores irregularly branched, 12–18 × 3–6 μm, tapering towards apex, swelling at base; sporodochial phialides monophialidic, fusoid to ampulliform, 7–13 × 3–6 μm, smooth, thin-walled. Conidia solitary, obovoid to ellipsoid, 9–13 × 5–8 μm, hyaline to subhyaline, guttulate, smooth, apex obtuse, base with inconspicuous to conspicuous hilum, 0.8–1.4 μm. Sexual morph: unknown. Culture characteristics: Colonies on PDA incubated at 25 °C in the dark with an average radial growth rate of 6.5–7.5 mm /day and occupying an entire 90 mm Petri dish in 14 days; Margin scalloped or irregularly round, center yellowish brown and white edges, aerial mycelium poorly developed, reverse similarity. Produced conidiomata sporodochial after 14 days or longer on colonies. Type specimen: China, Hainan Province: Wuzhishan National Nature Reserve, on diseased leaves of Photinia serratifolia, 20 May 2021, S. B. Liu (Holotype, HSAUP210421). Living ex-type culture: SAUCC 210421. Additional specimens examined: China, Hainan Province: Wuzhishan National Nature Reserve, on diseased leaves of Photinia serratifolia, 20 May 2021, S. B. Liu (HSAUP210423), living culture SAUCC 210423.Published as part of Liu, Shu-Bin, Zhang, Zhao-Xue, Liu, Rong-Yu, Mu, Tai-Chang, Zhang, Xiu-Guo, Li, Zhuang & Xia, Ji-Wen, 2022, Morphological and molecular identification of Ellipsoidisporodochium gen. nov. (Tubakiaceae, Diaporthales) in Hainan Province, China, pp. 259-266 in Phytotaxa 552 (4) on page 264, DOI: 10.11646/phytotaxa.552.4.3, http://zenodo.org/record/678582
Study of B c + → J / ψ D s + and B c + → J / ψ D s ∗ + decays in pp collisions at s = 13 TeV with the ATLAS detector
No full textAbstract
A study of
B
c
+
→
J
/
ψ
D
s
+
and
B
c
+
→
J
/
ψ
D
s
∗
+
decays using 139 fb−1 of integrated luminosity collected with the ATLAS detector from
s
= 13 TeV pp collisions at the LHC is presented. The ratios of the branching fractions of the two decays to the branching fraction of the
B
c
+
→ J/ψπ+ decay are measured:
B
B
c
+
→
J
/
ψ
D
s
+
/
B
B
c
+
→
J
/
ψπ
+
= 2.76 ± 0.47 and
B
B
c
+
→
J
/
ψ
D
s
∗
+
/
B
B
c
+
→
J
/
ψπ
+
= 5.33 ± 0.96. The ratio of the branching fractions of the two decays is found to be
B
B
c
+
→
J
/
ψ
D
s
∗
+
/
B
B
c
+
→
J
/
ψ
D
s
∗
+
= 1.93 ± 0.26. For the
B
c
+
→
J
/
ψ
D
s
∗
+
decay, the transverse polarization fraction, Γ±±/Γ, is measured to be 0.70 ± 0.11. The reported uncertainties include both the statistical and systematic components added in quadrature. The precision of the measurements exceeds that in all previous studies of these decays. These results supersede those obtained in the earlier ATLAS study of the same decays with
s
= 7 and 8 TeV pp collision data. A comparison with available theoretical predictions for the measured quantities is presented
Measurement of the branching fraction
No full textThe B
0
s
→ J/ψK
0
S
branching fraction is measured in a data sample corresponding to 0.41 fb−1
of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to
the penguin contributions affecting the sin 2β measurement from B
0
→ J/ψK
0
S
. The time-integrated
branching fraction is measured to be B(B
0
s
→ J/ψK
0
S
) = (1.83±0.28)×10−5
. This is the most precise
measurement to date
- …
