FoxK mediates TGF-β signalling during midgut differentiation in flies

Inductive signals across germ layers are important for the development of the endoderm in vertebrates and invertebrates (Tam, P.P., M. Kanai-Azuma, and Y. Kanai. 2003. Curr. Opin. Genet. Dev. 13:393–400; Nakagoshi, H. 2005. Dev. Growth Differ. 47:383–392). In flies, the visceral mesoderm secretes signaling molecules that diffuse into the underlying midgut endoderm, where conserved signaling cascades activate the Hox gene labial, which is important for the differentiation of copper cells (Bienz, M. 1997. Curr. Opin. Genet. Dev. 7:683–688). We present here a Drosophila melanogaster gene of the Fox family of transcription factors, FoxK, that mediates transforming growth factor β (TGF-β) signaling in the embryonic midgut endoderm. FoxK mutant embryos fail to generate midgut constrictions and lack Labial in the endoderm. Our observations suggest that TGF-β signaling directly regulates FoxK through functional Smad/Mad-binding sites, whereas FoxK, in turn, regulates labial expression. We also describe a new cooperative activity of the transcription factors FoxK and Dfos/AP-1 that regulates labial expression in the midgut endoderm. This regulatory activity does not require direct labial activation by the TGF-β effector Mad. Thus, we propose that the combined activity of the TGF-β target genes FoxK and Dfos is critical for the direct activation of lab in the endoderm

Single spin resonance driven by electric modulation of the g-factor anisotropy

We address the problem of electronic and nuclear spin resonance of an individual atom on a surface driven by a scanning tunneling microscope. Several mechanisms have been proposed so far, some of them based on the modulation of exchange and crystal field associated with a piezoelectric displacement of the adatom driven by the radio frequency (RF) tip electric field. Here we consider another mechanism, where the piezoelectric displacement modulates the g -factor anisotropy, leading both to electronic and nuclear spin flip transitions. We discuss thoroughly the cases of hydrogenated Ti ( S = 1 / 2 ) and Fe ( S = 2 ) on MgO, relevant for recent experiments. We model the system using two approaches. First, an analytical model that includes crystal field, spin orbit coupling, and hyperfine interactions. Second, we carry out density-functional-based calculations. We find that the modulation of the anisotropy of the g tensor due to the piezoelectric displacement of the atom is an additional mechanism for scanning tunneling microscopy (STM)-based single spin resonance that would be effective in S = 1 / 2 adatoms with large spin orbit coupling. In the case of hydrogenated Ti on MgO, we predict a modulation spin resonance frequency driven by the DC electric field of the tip.Fil: Ferrón, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; ArgentinaFil: Rodriguez, Santiago Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; ArgentinaFil: Gomez, Sergio Santiago. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; ArgentinaFil: Lado, Jose Luis. Aalto University; FinlandiaFil: Fernandez Rossier, Joaquín. International Iberian Nanotechnology Laboratory; Portugal. Universidad de Alicante; Españ

Probing the nature of the χc1(3872) state using radiative decays

The radiative decays χc1(3872) → ψ(2S)γ and χc1(3872) → J/ψγ are used to probe the nature of the χc1(3872) state using proton-proton collision data collected with the LHCb detector, corresponding to an integrated luminosity of 9 fb−1 . Using the B + → χc1(3872)K+ decay, the χc1(3872) → ψ(2S)γ process is observed for the frst time and the ratio of its partial width to that of the χc1(3872) → J/ψγ decay is measured to be Γχc1(3872)→ψ(2S)γ Γχc1(3872)→J/ψγ = 1.67 ± 0.21 ± 0.12 ± 0.04, where the frst uncertainty is statistical, the second systematic and the third is due to the uncertainties on the branching fractions of the ψ(2S) and J/ψ mesons. The measured ratio makes the interpretation of the χc1(3872) state as a pure D0D¯ ∗0 + D¯ 0D∗0 molecule questionable and strongly indicates a sizeable compact charmonium or tetraquark component within the χc1(3872) state

Measurement of the CKM angle γ with B± → D[K∓π±π±π∓]h± decays using a binned phase-space approach

The CKM angle γ is determined from CP-violating observables measured in B± → D[K∓π±π±π∓]h±, (h = K, π) decays, where the measurements are performed in bins of the decay phase-space of the D meson. Using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to a total integrated luminosity of 9 fb−1, γ is determined to be \gamma ={\left(54.8\begin{array}{c}+6.0\\ {}-5.8\end{array}\begin{array}{c}+0.6\\ {}-0.6\end{array}\begin{array}{c}+6.7\\ {}-4.3\end{array}\right)}^{\circ }, where the first uncertainty is statistical, the second systematic and the third from the external inputs on the coherence factors and strong phases of the D-meson decays

Measurement of the CKM angle γ using the B± → D∗h ± channels

 A measurement of the CP-violating observables from B± → D∗K± and B± → D∗π ± decays is presented, where D∗ (D) is an admixture of D∗0 and D¯ ∗0 (D0 and D¯ 0 ) states and is reconstructed through the decay chains D∗ → Dπ0/γ and D → K0 Sπ +π −/K0 SK+K−. The measurement is performed by analysing the signal yield variation across the D decay phase space and is independent of any amplitude model. The data sample used was collected by the LHCb experiment in proton-proton collisions and corresponds to a total integrated luminosity of 9 fb−1 at centre-of-mass energies of 7, 8 and 13 TeV. The CKM angle γ is determined to be (69+13 −14) ◦ using the measured CP-violating observables. The hadronic parameters r D∗K± B , rD∗π± B , δD∗K± B , δD∗π± B , which are the ratios and strong phase diferences between favoured and suppressed B± decays, are also reported

FastIC: a fast integrated circuit for the readout of high performance detectors

This work presents the 8-channel FastIC ASIC developed in CMOS 65 nm technology suitable for the readout of positive and negative polarity sensors in high energy physics experiments, Cherenkov detectors and time-of-flight systems. The front-end can be configured to perform analog summation of up to 4 single-ended channels before discrimination in view of improving time resolution when segmenting a SiPM. The outputs encode the time-of-arrival information and linear energy measurement which captures the peak amplitude of the input signal in the 5 µA–25 mA input peak current range. Power consumption of the ASIC is 12 mW/ch with default settings. Measurements of single photon time resolution with a red-light laser source and a HPK SiPM S13360-3050CS are ≈140 ps FWHM

Observation of the B+ → Jψη0K+ decay

Abstract: The B+ → Jψη0K+ decay is observed for the first time using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb−1 . The branching fraction of this decay is measured relative to the known branching fraction of the B+ → ψ(2S)K+ decay and found to be B(B+ → Jψη0K+) B(B+ → ψ(2S)K+) = (4.91 ± 0.47 ± 0.29 ± 0.07) × 10−2 , where the first uncertainty is statistical, the second is systematic and the third is related to external branching fractions. A first look at the J/ψη0 mass distribution is performed and no signal of intermediate resonances is observed

A search for rare B → Dµ+µ − decays

Abstract: A search for rare B → Dµ+µ − decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1 . No signifcant signals are observed in the non-resonant µ +µ − modes, and upper limits of B B0 → D 0 µ +µ − < 5.1 × 10−8 , B  meson with a c and u quark respectively in proton-proton collisions. Each result is either the frst such measurement or an improvement by three orders of magnitude on an existing limit. Separate upper limits are calculated when the muon pair originates from a J/ψ → µ +µ − decay. The branching fraction of B+ c → D+ s J/ψ multiplied by the fragmentation-fraction ratio is measured to be fc fu · B B + c → D+ s J/ψ = (1.63 ± 0.15 ± 0.13) × 10−5 , where the frst uncertainty is statistical and the second systematic

Measurement of + c production in pPb collisions at √sNN = 8.16 TeV at LHCb

A study of prompt + c production in proton-lead collisions is performed with the LHCb experiment at a centerof-mass energy per nucleon pair of 8.16 TeV in 2016 in pPb and Pbp collisions with an estimated integrated luminosity of approximately 12.5 and 17.4 nb−1 , respectively. The + c production cross section, as well as the + c to + c production cross-section ratio, are measured as a function of the transverse momentum and rapidity and compared to the latest theory predictions. The forward-backward asymmetry is also measured as a function of the + c transverse momentum. The results provide strong constraints on theoretical calculation and are a unique input for hadronization studies in different collision systems

Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at √sNN = 5.02 TeV with the LHCb detector

Flow harmonic coefficients, vn, which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of 5.02 TeV. The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features