57,764 research outputs found
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)
Measurement of CP observables in B-+/- -> D(*)K-+/- and B-+/- -> D(*)pi(+/-) decays
No full textMeasurements of CP observables in B-+/- -> D(*)K-+/- and B-+/- -> D(*)pi(+/-) decays are presented, where D(*) indicates a neutral Dor D* meson that is an admixture of D(*)(0) and (D) over bar(*)(0) states. Decays of the D* meson to the D pi(0)and D gamma final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the Bcandidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K-+/-pi(-/+), K+K- and pi(+)pi(-) final states. The analysis uses a sample of charged Bmesons produced in ppcollisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0fb- 1taken at centre- of- mass energies of root s = 7, 8 and 13 TeV, respectively. The study of B-perpendicular to -> D*K-perpendicular to and B-perpendicular to -> D*pi(perpendicular to) decays using a partial reconstruction method is the first of its kind, while the measurement of B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays is an update of previous LHCb measurements. The B-+/- -> DK +/- results are the most precise to date. (c) 2017 The Author. Published by Elsevier B. V
Measurement of the B0–B0 oscillation frequency Δmd with the decays B0→D−π+ and B0→ J/ψK∗0
No full textThe B
0
–B
0
oscillation frequency Δmd is measured by the LHCb experiment using a dataset corresponding
to an integrated luminosity of 1.0 fb−1
of proton–proton collisions at √
s = 7 TeV, and is found to be
Δmd
=0.5156±0.0051 (stat.)±0.0033 (syst.) ps−1
. The measurement is based on results from analyses
of the decays B
0
→ D
−π
+ (D
−
→ K
+π
−π
−) and B
0
→ J/ψK
∗0
(J/ψ →μ
+μ
−,K
∗0
→ K
+π
−) and
their charge conjugated modes
Cearagryllus Martins-Neto 1991
No full textCearagryllus Martins-Neto, 1991 Type species. Cearagryllus monstruosus Martins-Neto, 1991, by original designation. Remarks. The type species of the genus was based on a poorly preserved specimen, with an incomplete tegmen. A re-examination of the original material (Figure 2 B) reveals the existence of all diagnostic characters proposed for the subfamily. Species included (males): Cearagryllus monstruosus Martins-Neto, 1991 (the type species, Fig. 1 D); Cearagryllus gorochovi Martins-Neto, 1991 and Cearagryllus robustus Martins-Neto, 1991.Published as part of Martins-Neto, Rafael Gioia & Tassi, Lara Vaz, 2009, The Orthoptera (Ensifera) from the Santana formation (Early Cretaceous, Northeast Brazil): A statistical and paleoecological approach, with description of new taxa, pp. 21-37 in Zootaxa 2080 on page 23, DOI: 10.5281/zenodo.18734
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
Measurement of the CKM angle gamma from a combination of B->Dh analyses
No full textA combination of three LHCb measurements of the CKM angle gamma is presented. The decays B->DK and B->Dpi are used, where D denotes an admixture of D0 and D0-bar mesons, decaying into K+K-, pi+pi-, K+-pi-+, K+-pi-+pi+-pi-+, KSpi+pi-, or KSK+K- final states. All measurements use a dataset corresponding to 1.0 fb-1 of integrated luminosity. Combining results from B->DK decays alone a best-fit value of gamma = 72.0 deg is found, and confidence intervals are set gamma in [56.4,86.7] deg at 68% CL, gamma in [42.6,99.6] deg at 95% CL. The best-fit value of gamma found from a combination of results from B->Dpi decays alone, is gamma = 18.9 deg, and the confidence intervals gamma in [7.4,99.2] deg or [167.9,176.4] deg at 68% CL, are set, without constraint at 95% CL. The combination of results from B->DK and B->Dpi decays gives a best-fit value of gamma = 72.6 deg and the confidence intervals gamma in [55.4,82.3] deg at 68% CL, gamma in [40.2,92.7] deg at 95% CL are set. All values are expressed modulo 180 deg, and are obtained taking into account the effect of D0-D0bar mixing
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
Measurement of the D+/- production asymmetry in 7 TeV pp collisions
No full textThe asymmetry in the production cross-section \sigma of D+/- mesons, A_P = (\sigma(D+) - \sigma(D-))/(\sigma(D+) + \sigma(D-)), is measured in bins of pseudorapidity \eta and transverse momentum p_T within the acceptance of the LHCb detector. The result is obtained with a sample of D+ -> K_S pi+ decays corresponding to an integrated luminosity of 1.0 fb^-1, collected in pp collisions at a centre of mass energy of 7 TeV at the Large Hadron Collider. When integrated over the kinematic range 2.0 K_S pi+ decay is negligible. No significant dependence on \eta or p_T is observed
Allocearagryllus Martins-Neto
No full textAllocearagryllus Martins-Neto n. gen. Etymology. A different Cearagryllus Type species. Notocearagryllus leipnitzi Martins-Neto, 2002 b Diagnosis (male). Speculum approximately square (posterior margin slightly shorter than the anterior) with sp 1 converging on sp 2. CuA secondary branches beginning above the speculum (area supra-specular). Ve i n d-am situated at the boundary of anterior and anterolateral margins of the speculum. Curved d vein. Area below the posterior margin of the speculum similar in width to the adjacent ones. Discussion. Similar to Notocearagryllus Martins-Neto, 1999 in the general aspect of the tegmen morphology, differing however in features of the speculum: the posterior margin is slightly shorter than the anterior in Allocearagryllus n. gen. (posterior longer than anterior in Notocearagryllus); sp 1 converges on sp 2 in Allocearagryllus n. gen. (parallel in Notocearagryllus); sp 2 origin is at the base of the posterolateral margin of the speculum in Allocearagryllus n. gen. (at the posterior margin in Notocearagryllus). Additionally, the CuA secondary branches begin above the speculum in Allocearagryllus n. gen., and after the speculum in Notocearagryllus. Allocearagryllus n. gen. is also larger: tegmen length 25 mm as preserved (representing about 2 / 3 total length), compared with a total tegmen length of around 22 mm in Notocearagryllus. The features outlined above also distinguish the new genus from Cearagryllus. The d vein deflects at the anterior margin of the speculum in both Notocearagryllus and Cearagryllus, and d is curved forward in Allocearagryllus n. gen. The area below the posterior margin of the speculum is as wide as the adjacent ones in Allocearagryllus n. gen., wider in both Cearagryllus and Notocearagryllus.Published as part of Martins-Neto, Rafael Gioia & Tassi, Lara Vaz, 2009, The Orthoptera (Ensifera) from the Santana formation (Early Cretaceous, Northeast Brazil): A statistical and paleoecological approach, with description of new taxa, pp. 21-37 in Zootaxa 2080 on page 25, DOI: 10.5281/zenodo.18734
Allocearagryllus leipnitzi Martins-Neto, n. comb.
No full text<i>Allocearagryllus leipnitzi</i> Martins-Neto, n. comb. <p>(Fig. 1 C)</p> <p> 1. <i>Notocearagryllus leipnitzi</i> Martins-Neto, 2002 b</p> <p> <b>Etymology.</b> In honor of the foraminiferologist Prof. Dr. Itamar Ivo Leipnitz (UNISINOS-RS).</p> <p>Holotype. RGMN-T029, Martins-Neto Collection, housed at the Sociedade Brasileira de Paleoartropodologia – SBPr.</p> <p> Type locality, type stratum and age. As for <i>Notocearagryllus dutrae</i> Martins-Neto.</p> <p> <b>Diagnosis.</b> As for the genus.</p> <p> <b>Description</b> (Holotype, Fig. 1 C). Male tegmen 25 mm long as preserved (around 2/3 of the probable total length). <b>RP</b>, <b>CuA</b> and pre-lanceolate cell partially preserved. Speculum fairly square, with the anterior margin slightly curved than the posterior one. Anterolateral margin as long as the posterolateral one. <b>sp1</b> reaches the distal part of the posterior margin and the apical part of the anterolateral margin, parallel to the anal margin, converging on <b>sp2</b>; <b>sp2</b> reaches the distal part of the posterolateral margin and the apical part of the anterolateral margin, close to the <b>sp1</b> extremity. <b>CuA</b> secondary branches beginning above the speculum, and zigzag-shaped at their base, perpendicularly deflecting toward the apical margin, then running, slightly convergent, alongside the anal margin. Intraspecular cells numerous immediately under the speculum and also after it. Chords notably curved. The <b>d</b> vein partially fused to <b>CuP</b>, converging towards <b>CuA</b>. The <b>d-am</b> crossvein situated at the boundary of both anterior and anterolateral margins of the speculum. Apical part of <b>d</b> connected to the apical part of the posterolateral margin of the speculum by a long cross-vein. The area below the posterior margin of the speculum of similar width to the adjacent areas (area below the anterolateral margin of the speculum and area between the posterolateral margin of the speculum and the most proximal <b>CuA</b> secondary branch) and filled by parallel cross-veins.</p> <p> <b>Remarks.</b> This specimen was originally described by Martins-Neto (2002b) under the collection number RGMN-3000, now removed to a definitive collection number RGMN-T029 at the same Institution (SBPr).</p>Published as part of <i>Martins-Neto, Rafael Gioia & Tassi, Lara Vaz, 2009, The Orthoptera (Ensifera) from the Santana formation (Early Cretaceous, Northeast Brazil): A statistical and paleoecological approach, with description of new taxa, pp. 21-37 in Zootaxa 2080</i> on page 25, DOI: <a href="http://zenodo.org/record/187344">10.5281/zenodo.187344</a>
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