Scattering of dark pions in an Sp(4) gauge theory

In this work we consider strongly interacting dark matter candidates as composite states of $N_f=2$ fermions charged under a dark $Sp(4)$ gauge group in the fundamental representation. We give expressions that allow the calculation of correlation functions of two pseudo-Nambu-Goldstone-bosons with lattice field theory and present first results on the scattering phase shift in the isospin-2 channel in the theory from first principles. We give a lower limit on the dark matter particle mass by comparing our results with astrophysical constraints on the cross-section.Comment: 7 pages, 2 figures, The 40th International Symposium on Lattice Field Theory (Lattice 2023

Constraining exotic compact stars composed of bosonic and fermionic dark matter with gravitational wave events

We investigate neutron star-black hole (NS-BH) merger candidates as a test for compact exotic objects. Using the events GW190814, GW200105 and GW200115 measured by the LIGO-Virgo collabration, which represent a broad profile of the masses in the NS mass spectrum, we demonstrate the constraining power for the parameter spaces of compact stars consisting of dark matter for future measurements. We consider three possible cases of dark matter stars: self-interacting, purely bosonic or fermionic dark matter stars, stars consisting of a mixture of interacting bosonic and fermionic matter, as well as the limiting case of selfbound stars. We find that the scale of those hypothetical objects are dominated by the one of the strong interaction. The presence of fermionic dark matter requires a dark matter particle of the GeV mass scale, while the bosonic dark matter particle mass can be arbitrarily large or small. In the limiting case of a selfbound linear equation of state, we find that the vacuum energy of those configurations has to be similar to the one of QCD.Comment: 6 pages, 4 figures, 3 tables. In accordance with the CRC-TR 211 Data Management Policy, the research data for section 1 and 4 of this study are available as ancilliary files, while the research data of section 3 is made available under http://cloud.itp.uni-frankfurt.de/s/QYARcPkmqKW5ai

Benguela Niños: Physical Processes in Upwelling Regions and Long-Term Variability Cruise No. M189/1

April 16 – May 13, 2023 Walvis Bay (Namibia) – Walvis Bay (Namibia) BANIN

XCR1 + dendritic cells promote memory CD8 + T cell recall upon secondary infections with Listeria monocytogenes or certain viruses

International audienceNaive CD8(+) T cell priming during tumor development or many primary infections requires cross-presentation by XCR1(+) dendritic cells (DCs). Memory CD8(+) T lymphocytes (mCTLs) harbor a lower activation threshold as compared with naive cells. However, whether their recall responses depend on XCR1(+) DCs is unknown. By using a new mouse model allowing fluorescent tracking and conditional depletion of XCR1(+) DCs, we demonstrate a differential requirement of these cells for mCTL recall during secondary infections by different pathogens. XCR1(+) DCs were instrumental to promote this function upon secondary challenges with Listeria monocytogenes, vesicular stomatitis virus, or Vaccinia virus, but dispensable in the case of mouse cytomegalovirus. We deciphered how XCR1(+) DCs promote mCTL recall upon secondary infections with Listeria. By visualizing for the first time the in vivo choreography of XCR1(+) DCs, NK cells and mCTLs during secondary immune responses, and by neutralizing in vivo candidate molecules, we demonstrate that, very early after infection, mCTLs are activated, and attracted in a CXCR3-dependent manner, by NK cell-boosted, IL-12-, and CXCL9-producing XCR1(+) DCs. Hence, depending on the infectious agent, strong recall of mCTLs during secondary challenges can require cytokine-and chemokine-dependent cross-talk with XCR1(+) DCs and NK cells

Early-Career Researchers' Perspective on Future Colliders

International audienceSince its inception, the Large Hadron Collider (LHC) has significantly advanced particle physics and will continue to do so in the context of the High Luminosity LHC (HL-LHC) program to collect $3000$ fb$^{-1}$ by the end of 2041. The particle physics community worldwide is discussing which future collider could follow in the footsteps of the LHC and uncover yet inaccessible phenomena. To foster the discussion on this important topic among the young particle physicist community, the Early-Career Researchers (ECR) panel of the European Committee for Future Colliders (ECFA) has organized the Future Colliders for Early-Career Researchers workshop at CERN in September 2023. This document aims to summarise this event and present the ECR perspective, outline the key questions that came up during the discussions, and explore how ECRs can influence the decision process of future colliders community and beyond

The ECFA Early-Career Researchers Panel: Report for the year 2023

International audienceThe European Committee for Future Accelerators (ECFA) Early-Career Researcher (ECR) panel, which represents the interests of the ECR community to ECFA, presents in this document its initiatives and activities in the year 2023. This report summarises the process of the first big turnover in the panel composition at the start of 2023 and reports on the activities of the active working groups - either pursued from before or newly established. The overarching goal of the ECFA-ECR panel is to better understand and support the diverse interests of early-career researchers in the ECFA community and beyond