98,910 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 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 b-hadron masses
No full textMeasurements of b-hadron masses are performed with the exclusive decay modes B +→J/ψK +, B 0→J/ψK +, B0→J/ψKS0, Bs0→J/ψφ and Λb0→J/ψΛ using an integrated luminosity of 35pb -1 collected in pp collisions at a centre-of-mass energy of 7 TeV by the LHCb experiment. The momentum scale is calibrated with J/ψ→μ +μ - decays and verified to be known to a relative precision of 2 ×10 -4 using other two-body decays. The results are more precise than previous measurements, particularly in the case of the Bs0 and Λb0 masses
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
Measurement of the fragmentation fraction ratio fs/fd and its dependence on B meson kinematics
No full textThe relative production rate of B0s and B 0 mesons is determined with the hadronic decays B0s→D−sπ+ and B 0 → D − K +. The measurement uses data corresponding to 1.0 fb−1 of pp collisions at a centre-of-mass energy of s√=7 TeV recorded in the forward region with the LHCb experiment. The ratio of production rates, f s /f d , is measured to be 0.238 ± 0.004 ± 0.015 ± 0.021, where the first uncertainty is statistical, the second systematic, and the third theoretical. This is combined with a previous LHCb measurement to obtain f s /f d = 0.256 ± 0.020. The dependence of f s /f d on the transverse momentum and pseudorapidity of the B meson is determined using the decays B0s→D−sπ+ and B 0 → D −π+. There is evidence for a decrease with increasing transverse momentum, whereas the ratio remains constant as a function of pseudorapidity. In addition, the ratio of branching fractions of the decays B 0 → D − K + and B 0 → D −π+ is measured to be 0.0822 ± 0.0011 (stat) ± 0.0025 (syst)
Pseudocanthon pantanensis Nazare-Silva & Silva 2021, new species
No full text<i>Pseudocanthon pantanensis</i> Nazaré-Silva & Silva, new species <p>(Figs. 2D, 2G, 3E, 4D, 5E, 6E, 7B)</p> <p>urn:lsid:zoobank.org:act: 0A482135-A418-45E6-81E6-AA88A8B62102</p> <p> <b>Etymology</b>. The specific name is the Latinization of the Portuguese demonym “pantaneiro”, which refers to the inhabitants of the Pantanal wetlands, the place where this species has been recorded. It should be treated as a Latin third-declension adjective in the nominative case.</p> <p> <b>Diagnosis</b>. <i>Pseudocanthon pantanensis</i> is similar to <i>P</i>. <i>chaquensis</i> in having the pronotum with dense granulate microsculpture, well impressed at central portion (Fig. 2A); eighth stria of elytra extending across the basal half of the elytra, with shallow carina at basal portion (Fig. 2D); and posterior edge of metafemur lightly angulate at basal third, expanded towards the abdominal ventrites (Fig. 4D–E). However, <i>P</i>. <i>pantanensis</i> can be easily distinguished by its metallic green pygidium, with an orange band at posterior edge (Fig. 2G); parameres curved and pointed apically (Fig. 5E); frontolateral peripheral (FLP) endophallite sinuous, inferior portion rounded (Fig. 6E); accessory endophallite (AE) absent (Fig. 6E). In <i>P</i>. <i>chaquensis</i>, the pygidium is completely orange (Fig. 2H); the parameres are truncate at apex, with small obtuse projection at ventral edge (Fig. 5F); the frontolateral peripheral endophallite is elongate and bifurcate at inferior portion (Fig. 6F); and accessory endophallite is present, being small and elongate (Fig. 6F).</p> <p> <b>Description</b>. <b>Holotype. Length</b>. 4.1 mm. <b>Width</b>. 2.5 mm. <b>Colour</b>. Surface of body black with metallic green reflections; legs orange; orange spot on clypeus and on last abdominal ventrite. <b>Surface punctation and sculpturing</b>. In general, surface punctation consists of foveolate punctures. Surface of head, mesoventrite, metaventrite, elytra, abdomen, tibiae, and femora with dense and well-impressed granulate microsculpture; lateral edges and anterior angle of pronotum, hypomera, lateral edges, and anterior portion of metaventrite, mesepimeron, metanepisternum, epipleuron, tibiae, and femora with imbricate microsculpture. Pronotum with dense and well-impressed granulate microsculpture centrally (Fig. 2A). <b>Elytra</b>. Eighth elytral stria extending across the basal half of the elytra, with shallow carina at basal portion (Fig. 2D). <b>Legs</b>. Posterior edge of metafemur lightly angulate at basal third, expanded towards at abdominal ventrites (Fig. 4D). <b>Abdomen</b>. Metallic green pygidium, with an orange band at posterior edge (Fig. 2G) <b>Tegmen</b>. Apex of parameres curved and pointed (Fig. 5E). <b>Endophallus</b>. Frontolateral peripheral (FLP) endophallite sinuous, inferior portion rounded (Fig. 6E); acessory endophallite (AE) absent (Fig. 6E).</p> <p> <b>Type material</b>. 31♀ and 38♂. <b>Holotype. BRAZIL:</b> MATO GROSSO: Poconé, Pantanal, [17°50.73’S; 57°24.17’W], 15.XI.2011, pitfall with human feces, J. Silva — 1♂ (CEMT). <b>Paratypes. BRAZIL:</b> MATO GROSSO: Poconé, Pantanal, [17°50.73’S; 57°24.17’W], 15.XI.2011, pitfall with human feces, J. Silva — 1♂ (MZUFPA); Poconé, Pantanal, [17°50.73’S; 57°24.17’W], 15.XI.2011, pitfall with human feces, J. Silva — 29♀ 36♂ (CEMT); MATO GROSSO DO SUL: Corumbá, Passo da Lontra, [19°34’32.91’’S; 57°01’36.2’’W], 93 m, II.1996, J. Louzada & F. Vaz-de-Mello — 1♀ (CEMT); Corumbá, Passo da Lontra, [19°34’32.91’’S; 57°01’36.2’’W], 93 m, [no date], V. Lopes — 1♀ (CEMT).</p> <p> <b>Distribution</b>. Known from Brazil (Mato Grosso and Mato Grosso do Sul) (Fig. 7B). <b>Areas of endemism [South America]: Brazilian subregion</b>: South Brazilian dominion: Rondônia province. <b>Chacoan subregion</b>: Chacoan dominion: Chaco province (see Morrone 2014: fig. 12).</p>Published as part of <i>Nazaré-Silva, Everton E. & Silva, Fernando A. B., 2021, A taxonomic revision of the South American species of Pseudocanthon Bates, 1887 (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilini), pp. 61-86 in Zootaxa 5027 (1)</i> on page 76, DOI: 10.11646/zootaxa.5027.1.3, <a href="http://zenodo.org/record/5448088">http://zenodo.org/record/5448088</a>
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
Novantinoe iani Santos-Silva & Hovore 2007
No full text<p> <b> <i>Novantinoe iani</i> Santos-Silva & Hovore, 2007 (Fig. 20 G-I)</b> </p> <p> <i>Novantinoe iani</i> Santos-Silva & Hovore, 2007a: 601, figs. 32, 48; Santos-Silva & Martins, 2010: 200, fig. 276; Le Tirant & Santos-Silva, 2014b; 2; Monné <i>et al.,</i> 2017 a: 86; Botero & Almeida, 2019: 56; Botero & Gutiérrez, 2020: 8; Monné, 2023: 253.</p> <p> <b>Holotype:</b> ♂ " HOLOTYPE // PERU MADRE de DIOS / Rio Alto Madre de Dios / Pantiacolla Lodge 410-700 m / 12°39.4′S, 71°13.9′W / D. Brzoska 25-X-2000 // keys to / equatoriensis // <i>Novantinoe</i> / <i>iani</i> / Santos-Silva / & Hovore // MZSP 40830 ″.</p> <p> <b>Paratypes (3):</b> ♀ " PARÁTIPO // ECUADOR, Napo Pr. 2 km / N Ahuano, malaise trap / 05-15 Sept 2000 / F. T. Hovore, coll. // n. sp. keys to / equatoriensis // <i>Novantinoe</i> / <i>iani</i> / Santos-Silva / & Hovore // MZSP 40832″. ♀ " PARÁTIPO // ECUADOR, Napo Pr. / 25 km E. Atahualpa / 10-15 Sept 1998 / F. T. Hovore, coll. // <i>Novantinoe</i> / <i>iani</i> / Santos-Silva / & Hovore // MZSP 40833″. ♀ " PARÁTIPO // ECUADOR, Napo Pr. / Jatun Sacha Reserve,/ 04-06 Sept 2000 / F. T.Hovore,coll.// <i>Novantinoe</i> / <i>iani</i> / Santos-Silva / & Hovore // MZSP 40831″.</p>Published as part of <i>Botero, Juan Pablo, Casari, Sônia A. & Santos-Silva, Antonio, 2024, An illustrated catalog of Disteniidae (Coleoptera: Chrysomeloidea) type specimens deposited at the Museu de Zoologia da Universidade de São Paulo, pp. 1-38 in Papéis Avulsos de Zoologia 64</i> on pages 29-32, DOI: 10.11606/1807-0205/2024.64.012, <a href="http://zenodo.org/record/10942964">http://zenodo.org/record/10942964</a>
Inequalities between ∥f(A+B)∥ and ∥f(A)+f(B)∥
No full textAbstractThe conjecture posed by Aujla and Silva [J.S. Aujla, F.C. Silva, Weak majorization inequalities and convex functions, Linear Algebra Appl. 369 (2003) 217–233] is proved. It is shown that for any m-tuple of positive-semidefinite n×n complex matrices Aj and for any non-negative convex function f on [0,∞) with f(0)=0 the inequality ⦀f(A1)+f(A2)+⋯+f(Am)⦀⩽⦀ f(A1+A2+⋯+Am)⦀ holds for any unitarily invariant norm ⦀·⦀. It is also proved that ⦀f(A1)+f(A2)+⋯+f(Am)⦀⩾f(⦀A1+A2+⋯+Am⦀), where f is a non-negative concave function on [0,∞) and ⦀·⦀ is normalized
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
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