Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

We summarize recent work applying on-shell amplitude techniques to compute classical observables in scalar-tensor theories of gravity. We study gravitational and scalar radiation from spinning compact objects in two scenarios: theories without scalar hair where radiation is generated via curvature couplings of the scalar with the Gauss-Bonnet and Chern-Simons invariants, and theories with scalar hair where a direct conformal coupling leads to prolific dipole emission. Using the Kosower-Maybee-O'Connell (KMOC) formalism, we directly compute waveforms at leading order in the Post-Minkowskian (PM) expansion and the associated memory effects and radiated power. We examine their velocity scaling in the Post-Newtonian (PN) limit and comment on their phenomenological relevance. Throughout we use the spinor-helicity formalism and the unitary factorization techniques to derive the necessary on-shell amplitudes, efficiently computing observables to all orders in spin and velocity, offering powerful tools for gravitational-wave astronomy.

High-precision measurements of the Cosmic Microwave Background (CMB) will soon allow for the unprecedented detection of small-scale secondary anisotropies, such as the kinetic Sunyaev-Zel'dovich (kSZ) effect. Linking the kSZ power spectrum to the properties of ionising sources would provide an opportunity to use such observations to access astrophysical and cosmological information from the Epoch of Reionisation, including the morphology of ionised regions, while simultaneously improving CMB analyses. The aim of this work is to assess this potential of the kSZ power spectrum to measure reionisation-era galaxy properties. We repurpose the publicly available LoReLi II simulations, which track the evolution of neutral hydrogen during reionisation, to generate a training set of patchy kSZ angular power spectra. We then train an emulator using neural network regression in order to allow for efficient Bayesian inference, and conduct forecasts assuming mock observations from current and future CMB experiments. We find that measurements of the kSZ power spectrum from such surveys can provide meaningful constraints on several of the astrophysical model parameters of the LoReLi II suite, including the ionising escape fraction for which we expect a 14% relative error, on average. They also provide an independent measurement of the CMB optical depth, marginalised over the astrophysics and with error bars competitive with the cosmic variance limit from large scale surveys. The kSZ power spectrum offers a promising avenue for probing the properties of reionisation-era galaxies and providing an independent measurement of the CMB optical depth with upcoming CMB experiments. Since the error budget of our mock observations is dominated by emulator reconstruction errors, we expect our results could be further improved with a more extended simulation training set.

We report atomic mass measurements of the unstable nuclides 73−75 Ni, 73−78 Cu, and 74−78 Zn, which have been accomplished using multi-reflection time-of-flight mass spectrometry combined with new technical developments to resolve challenges for exotic-isotope identification and selection. The isotopes were produced in-flight at the RIKEN’s Radioactive Ion Beam Facility and delivered to the combined gas cell and multi-reflection system installed downstream of the ZeroDegree spectrometer. The incoming high-energy beam was energy-degraded and subsequently stopped in a helium gas cell. The energy degrader thickness was optimized using a new method that employs signals from plastic scintillators located upstream and downstream of the helium-filled gas cell. Extracted isotopes of interest were mass-selected by the in-MRTOF deflector method, for which we discuss simultaneous selection of multiple isobar chains. The ions of interest were identified unambiguously using β-decay-correlated mass measurements for the first time, which is demonstrated for 78 Zn. The new mass values are compared with literature values and recent measurements performed at JYFLTRAP and ISOLTRAP, where a generally good agreement is observed.

Abstract In this paper, we address double parton scattering (DPS) in pA collisions. Within the Light-Front approach, we formally derive the two contributions to the nuclear double parton distribution (DPD), namely: DPS1, involving two partons from the same nucleon, and DPS2, where the two partons belong to different parent nucleons. We then generalize the sum rule for hadron DPDs to the nuclear case and analytically show how all contributions combine to give the expected results. In addition partial sum rules for the DPDs related to DPS1 and DPS2 mechanisms are discussed for the first time. The deuteron system is considered for the first calculation of the nuclear DPD by using a realistic wave function obtained from the very refined nucleon-nucleon AV18 potential, embedded in a rigorous Poincaré covariant formalism. Results are used to test sum rules and properly verify that DPS1 contribution compares with the DPS2 one, although smaller. We also introduce EMC-like ratios involving nuclear and free DPDs to address the potential role of DPS in understanding in depth the EMC effect.

Ground-based surveys such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time require photometric calibration that is both long-term stable and spatially uniform at the sub-per cent level, even during non-photometric conditions. Achieving this precision motivates new approaches to characterize atmospheric transmission, particularly to mitigate grey extinction from clouds. The StarDICE experiment aims to establish a metrology chain linking laboratory standards to astrophysical fluxes with 1 mmag accuracy in the $\textit{griz}$ bands, a goal for which controlling variable atmospheric effects is essential. We present a method that corrects photometric measurements using simultaneous radiometric information from an infrared thermal camera. The grey-extinction model is fit on an image-by-image basis using thermal radiance excess and the difference between synthetic and instrumental fluxes of calibration stars, without requiring assumptions about the spatial structure of extinction. The method relies on a forward model that incorporates environmental monitoring, radiative-transfer simulations, and Gaia DR3 stellar catalogues. Using data from a remote observing system that repeatedly monitored two fields under diverse atmospheric conditions, we show that the corrections reduce residuals between corrected and reference magnitudes and produce extinction maps with 2-arcmin resolution and ~0.01 mag accuracy. Using this technique, we can recover data acquired under non-photometric conditions with a precision comparable to data obtained under photometric conditions. For the most affected exposures, the mean absolute error improves from 0.64 to 0.11 mag, and temporal extinction variations can be reduced to 0.025 mag per source. We discuss the implications of this technique for future surveys and outline directions for further refinement.

Precise experimental control and interrogation of molecules and calculations of their structure are enriching the investigation of nuclear and particle physics phenomena. Molecules containing heavy, octupole-deformed nuclei, such as radium, are of particular interest. Here, we report precision laser spectroscopy measurements and theoretical calculations of the structure of the radioactive radium monofluoride molecule 225Ra19F. Our results reveal fine details of the short-range electron-nucleus interaction, indicating the high sensitivity of this molecule to the distribution of magnetization, within the radium nucleus. These results provide a stringent test of the description of the electronic wave function inside the nuclear volume, highlighting the suitability of these molecules for investigating subatomic phenomena.

The status of several representative gauge theories on various quantum space-times, mainly focusing on Yang-Mills type extensions together with a few matrix model formulations is overviewed. The common building blocks are derivation based differential calculus possibly twisted and noncommutative analog of the Koszul connection. The star-products related to the quantum space-times are obtained from a combination of harmonic analysis of group algebras combined with Weyl quantization. The remaining problems inherent to gauge theories on Moyal spaces in their two different formulations are outlined. A family of gauge invariant matrix models on $\mathbb{R}^3_\lambda$, a deformation of $\mathbb{R}^3$ is presented among which a solvable model. The characterization of 11 new quantum Minkowski space-times through their $*$-algebras is given. A gauge theory of Yang-Mills type is constructed on one recently explored of these space-times and compared to its counterpart built on the popular $\kappa$-Minkowski.

Heavy-flavor quarks produced in proton-proton (pp) collisions provide a unique opportunity to investigate the evolution of quark-initiated parton showers from initial hard scatterings to final-state hadrons. By examining jets that contain heavy-flavor hadrons, this study explores the effects of both perturbative and nonperturbative QCD on jet formation and structure. The angular differences between various jet axes, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi mathvariant="normal">Δ</a:mi> <a:msub> <a:mi>R</a:mi> <a:mrow> <a:mi>axis</a:mi> </a:mrow> </a:msub> </a:math> , offer insight into the radiation patterns and fragmentation of charm quarks. The first measurement of <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"> <d:msup> <d:mi>D</d:mi> <d:mn>0</d:mn> </d:msup> </d:math> -tagged jet axes differences in pp collisions at <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"> <f:msqrt> <f:mi>s</f:mi> </f:msqrt> <f:mo>=</f:mo> <f:mn>5.02</f:mn> <f:mtext> </f:mtext> <f:mtext> </f:mtext> <f:mi>TeV</f:mi> </f:math> by the ALICE experiment at the LHC is presented for jets with transverse momentum <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"> <h:msubsup> <h:mi>p</h:mi> <h:mi mathvariant="normal">T</h:mi> <h:mtext>ch jet</h:mtext> </h:msubsup> <h:mo>≥</h:mo> <h:mn>10</h:mn> <h:mtext> </h:mtext> <h:mtext> </h:mtext> <h:mi>GeV</h:mi> <h:mo>/</h:mo> <h:mi>c</h:mi> </h:math> and <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:msup> <k:mi>D</k:mi> <k:mn>0</k:mn> </k:msup> </k:math> mesons with <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:mrow> <m:msubsup> <m:mrow> <m:mi>p</m:mi> </m:mrow> <m:mrow> <m:mi mathvariant="normal">T</m:mi> </m:mrow> <m:mrow> <m:msup> <m:mrow> <m:mi mathvariant="normal">D</m:mi> </m:mrow> <m:mrow> <m:mn>0</m:mn> </m:mrow> </m:msup> </m:mrow> </m:msubsup> <m:mo>≥</m:mo> <m:mn>5</m:mn> <m:mtext> </m:mtext> <m:mtext> </m:mtext> <m:mi>GeV</m:mi> <m:mo>/</m:mo> <m:mi>c</m:mi> </m:mrow> </m:math> . In this <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"> <q:msup> <q:mi>D</q:mi> <q:mn>0</q:mn> </q:msup> </q:math> -meson-tagged jet measurement, three jet axis definitions, each with different sensitivities to soft, wide-angle radiation, are used: the standard axis, soft drop groomed axis, and winner-takes-all axis. Measurements of the radial distributions of <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"> <s:msup> <s:mi>D</s:mi> <s:mn>0</s:mn> </s:msup> </s:math> mesons with respect to the jet axes, <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:mrow> <u:mi mathvariant="normal">Δ</u:mi> <u:msub> <u:mrow> <u:mi>R</u:mi> </u:mrow> <u:mrow> <u:mrow> <u:mi>axis</u:mi> </u:mrow> <u:mtext>−</u:mtext> <u:msup> <u:mrow> <u:mi mathvariant="normal">D</u:mi> </u:mrow> <u:mrow> <u:mn>0</u:mn> </u:mrow> </u:msup> </u:mrow> </u:msub> </u:mrow> </u:math> , are reported, along with the angle, <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"> <y:mi mathvariant="normal">Δ</y:mi> <y:msub> <y:mi>R</y:mi> <y:mrow> <y:mi>axis</y:mi> </y:mrow> </y:msub> </y:math> , between the three jet axes. The <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline"> <bb:msup> <bb:mi>D</bb:mi> <bb:mn>0</bb:mn> </bb:msup> </bb:math> meson emerges as the leading particle in these jets, closely aligning with the winner-takes-all axis and diverging from the standard jet axis. The results also examine how varying the sensitivity to soft radiation with grooming influences the orientation of the soft drop jet axis and uncover that charm-jet structure is more likely to survive grooming when the soft drop axis is further from the <db:math xmlns:db="http://www.w3.org/1998/Math/MathML" display="inline"> <db:msup> <db:mi>D</db:mi> <db:mn>0</db:mn> </db:msup> </db:math> direction, providing further evidence of the dead-cone effect recently measured by ALICE.

The extragalactic background is composed of the emission from all astrophysical sources, both resolved and unresolved, in addition to any diffuse components. In the last decade, there has been significant progress in our understanding of the cosmic history of extragalactic emissions associated with stellar evolution and accretion onto supermassive black holes, largely enabled by the extensive body of multi-wavelength data. The brightness of the extragalactic sky is now measured in photons, neutrinos, and cosmic rays, using observatories on the ground, in the sea, and in the ice, satellites in Earth orbit, and probes at the edge of the solar system. This wealth of disparate data is essential to unraveling the mysteries of the source populations that contribute to the extragalactic background. In this contribution, we present an open database containing the most comprehensive collection of measurements of the extragalactic background spectrum to date. The combination of multi-messenger measurements over 27 frequency decades allows us to estimate the energy density of most extragalactic background components with an uncertainty of less than 30%. We explore the consistency of this cosmic inventory of the observed fields of relativistic particles populating the Universe with the cosmic history of star formation and accretion around supermassive black holes. Models incorporating these cosmic histories, as well as the redshift-dependent luminosity functions of extragalactic sources, currently match the electromagnetic component of the extragalactic background spectrum over 14 frequency decades, from the near UV to sub-TeV gamma rays. The knowledge gained from synthetic population models in the electromagnetic bands may become a crucial tool for understanding the origin of the most energetic extragalactic messengers, neutrinos and ultrahigh-energy cosmic rays.