Plants are less negatively affected by flooding when growing in species-rich plant communities

Flooding is expected to increase in frequency and severity in the future. The ecological consequences of flooding are the combined result of species-specific plant traits and ecological context. However, the majority of past flooding research has focused on individual model species under highly controlled conditions. An early summer flooding event in a grassland biodiversity experiment in Jena, Germany, provided the opportunity to assess flooding responses of 60 grassland species in monocultures and 16-species mixtures. We examined plant biomass, species-specific traits (plant height, specific leaf area (SLA), root aerenchyma, starch content) and soil porosity. We found that, on average, plant species were less negatively affected by the flood when grown in higher-diversity plots in July 2013. By September 2013, grasses were unaffected by the flood regardless of plant diversity, and legumes were severely negatively affected regardless of plant diversity. Plants with greater SLA and more root aerenchyma performed better in September. Soil porosity was higher in higher-diversity plots and had a positive effect on plant performance. As floods become more frequent and severe in the future, growing flood-sensitive plants in higher-diversity communities and in soil with greater soil aeration may attenuate the most negative effects of flooding.</p

Model-independent measurement of charm mixing parameters in <math display="inline"><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">(</mo><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>-</mo></msup><mo stretchy="false">)</mo><msup><mi>μ</mi><mo>-</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>μ</mi></msub><mi>X</mi></math> decays

International audienceA measurement of charm mixing and CP-violating parameters is reported, using B¯→D0(→KS0π+π-)⁢μ-ν¯μX decays reconstructed in proton-proton collisions collected by the LHCb experiment during the years 2016 to 2018, corresponding to an integrated luminosity of 5.4  fb-1. The measured mixing and CP-violating parameters are xCP=[4.29±1.48(stat)±0.26(syst)]×10-3, yCP=[12.61±3.12(stat)±0.83(syst)]×10-3, Δx=[-0.77±0.93(stat)±0.28(syst)]×10-3, Δy=[3.01±1.92(stat)±0.26(syst)]×10-3. The results are complementary to and consistent with previous measurements. A combination with the recent LHCb analysis of D*+→D0(→KS0π+π-)π+ decays is reported

First measurement of the Z→μ+μ−Z\rightarrow \mu^+ \mu^- angular coefficients in the forward region of pppp collisions at s=13\sqrt{s}=13 TeV

The first study of the angular distribution of $\mu^+ \mu^-$ pairs produced in the forward rapidity region via the Drell-Yan reaction $pp \rightarrow \gamma^{*}/Z +X \rightarrow l^+ l^- + X$ is presented, using data collected with the LHCb detector at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.1 $\rm{fb}^{-1}$. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the $Z$-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton

Search for the rare decays W+→Ds+γW^+ \to D^+_s\gamma and Z→D0γZ \to D^0\gamma at LHCb

International audienceA search for the rare decays and is performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13, corresponding to an integrated luminosity of 2.0. No significant signal is observed for either decay mode and upper limits on their branching fractions are set using and decays as normalization channels. The upper limits are and at 95% confidence level for the and decay modes, respectively. This is the first reported search for the decay, while the upper limit on the branching fraction improves upon the previous best limit

Measurement of the Prompt <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math> Nuclear Modification Factor in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>p</mml:mi><mml:mtext>−</mml:mtext><mml:mi>Pb</mml:mi></mml:mrow></mml:math> Collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msqrt><mml:mrow><mml:msub><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mi>N</mml:mi><mml:mi>N</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msqrt><mml:mo>=</mml:mo><mml:mn>8.16</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:mrow></mml:math>

The production of prompt $D^0$ mesons in proton-lead collisions in the forward and backward configurations at a center-of-mass energy per nucleon pair of $\sqrt{s_\mathrm{NN}} = 8.16~\mathrm{TeV}$ is measured by the LHCb experiment. The nuclear modification factor of prompt $D^0$ mesons is determined as a function of the transverse momentum $p_\mathrm{T}$, and rapidity in the nucleon-nucleon center-of-mass frame $y^*$. In the forward rapidity region, significantly suppressed production is measured, which provides a stringent test of the nuclear parton distribution down to the very low Bjorken-$x$ region of $\sim 10^{-6}$. In the backward rapidity region, a suppression with a significance of 2 - 4 standard deviations compared to theoretical predictions is observed in the kinematic region of $p_\mathrm{T}>6~\mathrm{GeV}/c$ and -3.25 D0 mesons in proton-lead collisions in both the forward and backward rapidity regions at a center-of-mass energy per nucleon pair of sNN=8.16  TeV is measured by the LHCb experiment. The nuclear modification factor of prompt D0 mesons is determined as a function of the transverse momentum pT, and the rapidity in the nucleon-nucleon center-of-mass frame y*. In the forward rapidity region, significantly suppressed production with respect to pp collisions is measured, which provides significant constraints on models of nuclear parton distributions and hadron production down to the very low Bjorken-x region of ∼10-5. In the backward rapidity region, a suppression with a significance of 2.0–3.8 standard deviations compared to parton distribution functions in a nuclear environment expectations is found in the kinematic region of pT>6  GeV/c and -3.25<y*<-2.5, corresponding to x∼0.01.The production of prompt D^0$mesons in proton-lead collisions in the forward and backward configurations at a center-of-mass energy per nucleon pair of$\sqrt{s_\mathrm{NN}} = 8.16~\mathrm{TeV}$is measured by the LHCb experiment. The nuclear modification factor of prompt$D^0$mesons is determined as a function of the transverse momentum$p_\mathrm{T}$, and rapidity in the nucleon-nucleon center-of-mass frame$y^*$. In the forward rapidity region, significantly suppressed production with respect to$pp$collisions is measured, which provides significant constraints of nuclear parton distributions and hadron production down to the very low Bjorken-$x$region of$\sim 10^{-5}$. In the backward rapidity region, a suppression with a significance of 2.0 - 3.8 standard deviations compared to nPDF expectations is found in the kinematic region of$p_\mathrm{T}>6~\mathrm{GeV}/c$and$-3.25<y^*<-2.5$, corresponding to$x\sim 0.01$

First measurement of the Z→μ+μ−Z\rightarrow \mu^+ \mu^- angular coefficients in the forward region of pppp collisions at s=13\sqrt{s}=13 TeV

International audienceThe first study of the angular distribution of $\mu^+ \mu^-$ pairs produced in the forward rapidity region via the Drell-Yan reaction $pp \rightarrow \gamma^{*}/Z +X \rightarrow l^+ l^- + X$ is presented, using data collected with the LHCb detector at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.1 $\rm{fb}^{-1}$. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the $Z$-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton