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Higher derivative couplings with multi-tensor multiplets in 6D supergravity, action and anomalies
No full textInternational audienceWe revisit six-dimensional (1,0) supergravity coupled to nT tensor multiplets and Yang-Mills fields for nT>1 for which no covariant action exists. We construct the action in the Henneaux-Teitelboim approach and in the presence of a gauge anomaly. We moreover obtain the supersymmetric Green-Schwarz counterterm for the gravitational anomaly for arbitrary matter content
Quantum Gravity, Hydrodynamics and Emergent Cosmology: A Collection of Perspectives
No full textInternational audienceThis collection of perspective pieces captures recent advancements and reflections from a dynamic research community dedicated to bridging quantum gravity, hydrodynamics, and emergent cosmology. It explores four key research areas: (a) the interplay between hydrodynamics and cosmology, including analog gravity systems; (b) phase transitions, continuum limits and emergent geometry in quantum gravity; (c) relational perspectives in gravity and quantum gravity; and (d) the emergence of cosmological models rooted in quantum gravity frameworks. Each contribution presents the distinct perspectives of its respective authors. Additionally, the introduction by the editors proposes an integrative view, suggesting how these thematic units could serve as foundational pillars for a novel theoretical cosmology framework termed "hydrodynamics on superspace"
Les ébauches zoliennes pour enseigner la langue et la culture à des étudiants internationaux
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Search for the Higgs boson decays to a , , or K meson and a photon in proton-proton collisions at = 13 TeV
No full textInternational audienceThree rare decay processes of the Higgs boson to a (770), (1020), or K(892) meson and a photon are searched for using = 13 TeV proton-proton collision data collected by the CMS experiment at the LHC. Events are selected assuming the mesons decay into a pair of charged pions, a pair of charged kaons, or a charged kaon and pion, respectively. Depending on the Higgs boson production mode, different triggering and reconstruction techniques are adopted. The analyzed data sets correspond to integrated luminosities up to 138 fb, depending on the reconstructed final state. After combining various data sets and categories, no significant excess above the background expectations is observed. Upper limits at 95% confidence level on the Higgs boson branching fractions into (770), (1020), and K(892) are determined to be 3.7 10, 3.0 10, and 3.0 10, respectively. In case of the (770) and (1020) channels, these are the most stringent experimental limits to date
Convergence d'un système de Zakharov stochastique vers l'équation de NLS multiplicative
No full textInternational audienceWe study the convergence of a Zakharov system driven by a time white noise, colored in space, to a multiplicative stochastic nonlinear Schrödinger equation, as the ion-sound speed tends to infinity. In the absence of noise, the conservation of energy gives bounds on the solutions, but this evolution becomes singular in the presence of the noise. To overcome this difficulty, we show that the problem may be recasted in the diffusion-approximation framework, and make use of the perturbed test-function method. We also obtain convergence in probability. The result is limited to dimension one, to avoid too much technicalities. As a prerequisite, we prove the existence and uniqueness of regular solutions of the stochastic Zakharov system.Nous étudions la convergence d'un système de Zakharov forcé par un bruit blanc temporel, coloré en espace, vers une équation de Schrödinger non linéaire stochastique multiplicative. En l'absence de bruit, la conservation de l'énergie donne des bornes uniformes sur les solutions, mais cette évolution devient singulière en présence du bruit. Pour surmonter cette difficulté, nous montrons que le problème peut être replacé dans le cadre de l'approximation-diffusion, et nous utilisons la méthode de la fonction-test perturbée. Nous obtenons également une convergence en probabilité. Le résultat est limité à la dimension un, pour éviter trop de technicité. En préambule, nous prouvons l'existence et l'unicité de solutions régulières du système de Zakharov stochastique
Search for dark matter produced in association with a pair of bottom quarks in proton-proton collisions at = 13 TeV
No full textInternational audienceA search for dark matter (DM) particles produced in association with bottom quarks is presented. The analysis uses proton-proton collision data at a center-of-mass energy of = 13 TeV, corresponding to an integrated luminosity of 138 fb. The search is performed in the final state with large missing transverse momentum and a pair of jets originating from bottom quarks. No significant excess of data is observed with respect to the standard model expectation. Results are interpreted in the context of a type-II two-Higgs-doublet model with an additional light pseudoscalar (2HDM+a). An upper limit is set on the mass of the lighter pseudoscalar, excluding masses up to 260 GeV at 95% confidence level. This is the first search at the LHC to probe DM produced in association with two nonresonant bottom quarks in the 2HDM+a model. Sensitivity to the parameter space with the ratio of the vacuum expectation values of the two Higgs doublets, , greater than 15 is achieved, capitalizing on the enhancement of couplings between pseudoscalars and bottom quarks with high
Measurement of the Drell--Yan forward-backward asymmetry and of the effective leptonic weak mixing angle in proton-proton collisions at = 13 TeV
No full textInternational audienceThe forward-backward asymmetry in Drell-Yan production and the effective leptonic electroweak mixing angle are measured in proton-proton collisions at = 13 TeV, collected by the CMS experiment and corresponding to an integrated luminosity of 138 fb. The measurement uses both dimuon and dielectron events, and is performed as a function of the dilepton mass and rapidity. The unfolded angular coefficient is also extracted, as a function of the dilepton mass and rapidity. Using the CT18Z set of parton distribution functions, we obtain = 0.23157 0.00031, where the uncertainty includes the experimental and theoretical contributions. The measured value agrees with the standard model fit result to global experimental data. This is the most precise measurement at a hadron collider, with a precision comparable to the results obtained at LEP and SLD
Lighting up the Photon Wigner Distribution via Dilepton Productions
No full textInternational audienceWe present a systematic investigation of lepton pair production through photon-photon fusion processes in heavy-ion collisions. It is demonstrated that the dilepton production at a given impact parameter () with a fixed transverse momentum imbalance () can be factorized into a unified formula in terms of the Wigner photon distribution of heavy nuclei. We show that this framework provides a comprehensive description of all the relevant data from RHIC to the LHC, with a strong evidence that the quasi-real photon can be radiated not only from the nucleus as a whole, standing for the coherent contribution, but also from the sub-structures inside the nucleus, representing the incoherent contribution. Further predictions are made for the anisotropies in the correlations between , , and the dilepton transverse momentum (). This will help us to constrain the photon Wigner distribution which plays a crucial role to study the gluonic matter of nucleus at small- through the diffractive photoproduction processes in heavy ion collision
Search for a standard model-like Higgs boson in the mass range between 70 and 110 GeV in the diphoton final state in proton-proton collisions at = 13 TeV
No full textInternational audienceThe results of a search for a standard model-like Higgs boson decaying into two photons in the mass range between 70 and 110 GeV are presented. The analysis uses the data set collected by the CMS experiment in proton-proton collisions at = 13 TeV corresponding to integrated luminosities of 36.3 fb, 41.5 fb and 54.4 fb during the 2016, 2017, and 2018 LHC running periods, respectively. No significant excess over the background expectation is observed and 95% confidence level upper limits are set on the product of the cross section and branching fraction for decays of an additional Higgs boson into two photons. The maximum deviation with respect to the background is seen for a mass hypothesis of 95.4 GeV with a local (global) significance of 2.9 (1.3) standard deviations. The observed upper limit ranges from 15 to 73 fb
Exploring orbital angular momentum and spin-orbit correlation for gluons at the Electron-Ion Collider
No full textInternational audienceIn our previous work [Phys. Rev. Lett. 128, 182002 (2022)], we introduced a pioneering observable aimed at experimentally detecting the orbital angular momentum (OAM) of gluons. Our focus was on the longitudinal double spin asymmetry observed in exclusive dijet production during electron-proton scattering. We demonstrated the sensitivity of the angular correlation between the scattered electron and proton as a probe for gluon OAM at small- and its intricate interplay with gluon helicity. This current work provides a comprehensive exposition, diving further into the aforementioned calculation with added elaboration and in-depth analysis. We reveal that, in addition to the gluon OAM, one also gains access to the spin-orbit correlation of gluons. We supplement our work with a detailed numerical analysis of our observables for the kinematics of the Electron-Ion Collider. In addition to dijet production, we also consider the recently proposed semi-inclusive diffractive deep inelastic scattering process which potentially offers experimental advantages over dijet measurements. Finally, we investigate quark-channel contributions to these processes and find an unexpected breakdown of collinear factorization