Sensitivity to two photon exchange in time-like form factor measurements at PANDA

At PANDA (FAIR) proton time-like form factors measurements are foreseen. In this work, following detailed simulations, we study the sensitivity to possible two photon exchange contribution in the annihilation process $\bar p+p\to e^++e^-$, through the induced asymmetry in the angular distribution. Asymmetries related to systematic errors are also investigated

Time-like observables: differential cross section and angular asymmetry

Time-like electromagnetic form factors can be obtained from unpolarized measurements of the differential cross section in proton antiproton annihilation in a pair of leptons, as $\overline{p}$ + p ↔ e+ + e− , with the PANDA detector at FAIR. We study the sensitivity of such measurements and focus on observables such as the angular asymmetry and the ratio of electric to magnetic form factors. We also collect useful formulas and references for future simulations and studies

Study of exclusive one-pion and one-eta production using hadron and dielectron channels in pp reactions at kinetic beam energies of 1.25 GeV and 2.2 GeV with HADES

We present measurements of exclusive ensuremathπ+,0 and η production in pp reactions at 1.25GeV and 2.2GeV beam kinetic energy in hadron and dielectron channels. In the case of π+ and π0 , high-statistics invariant-mass and angular distributions are obtained within the HADES acceptance as well as acceptance-corrected distributions, which are compared to a resonance model. The sensitivity of the data to the yield and production angular distribution of Δ (1232) and higher-lying baryon resonances is shown, and an improved parameterization is proposed. The extracted cross-sections are of special interest in the case of pp → pp η , since controversial data exist at 2.0GeV; we find \ensuremathσ=0.142±0.022 mb. Using the dielectron channels, the π0 and η Dalitz decay signals are reconstructed with yields fully consistent with the hadronic channels. The electron invariant masses and acceptance-corrected helicity angle distributions are found in good agreement with model predictions

Sensitivity to two photon exchange in time-like form factor measurements at PANDA

At PANDA (FAIR) proton time-like form factors measurements are foreseen. In this work, following detailed simulations, we study the sensitivity to possible two photon exchange contribution in the annihilation process $\bar p+p\to e^++e^-$, through the induced asymmetry in the angular distribution. Asymmetries related to systematic errors are also investigated

Time-like observables: differential cross section and angular asymmetry

Time-like electromagnetic form factors can be obtained from unpolarized measurements of the differential cross section in proton antiproton annihilation in a pair of leptons, as $\overline{p}$ + p ↔ e+ + e− , with the PANDA detector at FAIR. We study the sensitivity of such measurements and focus on observables such as the angular asymmetry and the ratio of electric to magnetic form factors. We also collect useful formulas and references for future simulations and studies

Stiffness-induced cancer-associated fibroblasts are responsible for immunosuppression in a platelet-derived growth factor ligand-dependent manner

International audienceAbstract Pancreatic ductal adenocarcinoma (PDAC) is associated with a vast stromal reaction that arises mainly from cancer-associated fibroblasts (CAFs) and promotes both immune escape and tumor growth. Here, we used a mouse model with deletion of the activin A receptor ALK4 in the context of the KrasG12D mutation, which strongly drives collagen deposition that leads to tissue stiffness. By ligand–receptor analysis of single-cell RNA-sequencing data, we identified that, in stiff conditions, neoplastic ductal cells instructed CAFs through sustained platelet-derived growth factor (PDGF) signaling. Tumor-associated tissue rigidity resulted in the emergence of stiffness-induced CAFs (siCAFs) in vitro and in vivo. Similar results were confirmed in human data. siCAFs were able to strongly inhibit CD8+ T-cell responses in vitro and in vivo, promoting local immunosuppression. More importantly, targeting PDGF signaling led to diminished siCAF and reduced tumor growth. Our data show for the first time that early paracrine signaling leads to profound changes in tissue mechanics, impacting immune responses and tumor progression. Our study highlights that PDGF ligand neutralization can normalize the tissue architecture independent of the genetic background, indicating that finely tuned stromal therapy may open new therapeutic avenues in pancreatic cancer