Measurement of the branching fraction of B → D(∗)π`ν at Belle using hadronic tagging in fully reconstructed events

We report a measurement of the branching fraction of the decay B→D(∗)πℓν. The analysis uses 772×106 BB¯ pairs produced in e+e−→Υ(4S) data recorded by the Belle experiment at the KEKB asymmetric-energy e+e− collider. The tagging B meson in the decay is fully reconstructed in a hadronic decay mode. On the signal side, we reconstruct the decay B→D(∗)πℓν (ℓ=e,μ). The measured branching fractions are (B+→D−π+ℓ+ν) = [4.55 ± 0.27 (stat.) ± 0.39 (syst.)]×10−3, (B0→D¯0π−ℓ+ν) = [4.05 ± 0.36 (stat.) ± 0.41 (syst.)]×10−3, (B+→D∗−π+ℓ+ν) = [6.03 ± 0.43 (stat.) ± 0.38 (syst.)]×10−3, and (B0→D¯∗0π−ℓ+ν) = [6.46 ± 0.53 (stat.) ± 0.52 (syst.)]×10−3. These are in good agreement with the current world average values

Observation of Beam Spin Asymmetries in the Process ep → e\u27π⁺π⁻ X with CLAS 12

The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function e(x), which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function G⊥1. A clear sign change is observed around the ρ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark

Beyond humanization and de-immunization: tolerization as a method for reducing the immunogenicity of biologics

Immune responses to some monoclonal antibodies (mAbs) and biologic proteins interfere with their efficacy due to the development of anti-drug antibodies (ADA). In the case of mAbs, most ADA target ‘foreign’ sequences present in the complementarity determining regions (CDRs). Humanization of the mAb sequence is one approach that has been used to render biologics less foreign to the human immune system. However, fully human mAbs can also drive immunogenicity. De-immunization (removing epitopes) has been used to reduce biologic protein immunogenicity. Here, we discuss a third approach to reducing the immunogenicity of biologics: introduction of Treg epitopes that stimulate Treg function and induce tolerance to the biologic protein. Supplementing humanization (replacing xenosequences with human) and de-immunization (reducing T effector epitopes) with tolerization (introducing Treg epitopes) where feasible, as a means of improving biologics ‘quality by design’, may lead to the development of ever more clinically effective, but less immunogenic, biologics

Observation of Transverse Λ/¯Λ Hyperon Polarization in e+e− Annihilation at Belle

We report the first observation of the spontaneous polarization of Λ and ¯Λ hyperons transverse to the production plane in e+e− annihilation, which is attributed to the effect arising from a polarizing fragmentation function. For inclusive Λ/¯Λ production, we also report results with subtracted feed-down contributions from Σ0 and charm. This measurement uses a dataset of 800.4  fb−1 collected by the Belle experiment at or near a center-of-mass energy of 10.58 GeV. We observe a significant polarization that rises with the fractional energy carried by the Λ/¯Λ hyperon

Observation of Beam Spin Asymmetries in the Process Ep→e′π+π−X with CLAS12.

The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function e (x), which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function G⊥1 . A clear sign change is observed around the ρ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

International audienceThe PHENIX collaboration presents first measurements of low-momentum (0.41  GeV/c) direct-photon yield dNγdir/dη is a smooth function of dNch/dη and can be well described as proportional to (dNch/dη)α with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high pT (>5  GeV/c), but when results from different collision energies are compared, an additional sNN-dependent multiplicative factor is needed to describe the integrated-direct-photon yield