• Tuesday 10 January 2023 at 10:15  in A315 and using Zoom: Tuomas Lappi (Jyväskylä)
    EIC – the most powerful microscope on Earth
    This seminar will discuss the physics program of the Electron-Ion Collider EIC. The EIC is a collider for DIS, deep inelastic scattering, that should start taking data in the early 2030’s. It will be built at Brookhaven, combining the existing proton and ion beams of RHIC with a new electron accelerator. The EIC will be the first collider energy DIS experiment with polarized protons, and the first to collide heavy ions. It will also have a luminosity orders of magnitude higher than previous HERA experiments. These features allow the EIC to access new aspects of gluonic degrees of freedom in ordinary matter. The nuclear beam will enable precision studies of gluon saturation in a high energy nucleus. Polarization gives access to the role of gluons in the proton spin, moving us closer to understanding the proton spin puzzle. The high luminosity enables measurements of rare exclusive processes that lead to a multidimensional mapping of the structure of the proton.
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  • Tuesday 24 January 2023 at 10:15  using Zoom: Sophia Han (T.D.Lee Institute, Shanghai)
    Probing exotic matter in neutron star cores with g-mode oscillations
    The neutron star interior reaches ultra-high densities with its composition details unknown. Gravitational wave emissions from neutron stars are promising probes that can help reveal novel phases of dense matter. In this talk, I will describe a first study of the principle g-mode oscillation in hybrid stars containing quark matter through hadron-quark crossover transition, and compare with results obtained for a first-order transition via the Gibbs mixed-phase construction. I will discuss the distinct behaviors of the adiabatic and equilibrium sound speeds in theoretical models of the equation of state (EoS) for neutron-star matter, as well as their connections to astrophysical observables.
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  • Tuesday 31 January 2023 at 10:15 in A315 and using Zoom: Niklas Ramberg (Mainz)
    Bubbles from Dark Confinement with Holography
    Abstract:Gravitational waves emitted from strongly coupled QFTs are, at present, a daunting task to accurately predict due to the strong coupling. In this talk, we demonstrate how to predict the gravitational wave spectra of such theories using holography and lattice data input for a pure SU(3) Yang-Mills theory with minor uncertainties. We will elaborate on how we obtain an effective potential using holography with the free energy landscape approach and formulate an effective action. Once the effective action is in our grasp, we will use this to study bubble nucleation to predict the gravitational wave spectra.
    Link to video:
  • Tuesday 7 February 2023 at 10:15 in A315 and using Zoom: Andrea Malara (Brussels U, IIHE)
    Reconstruction and calibration of jets at the CMS experiment: Run 2 and perspective for Run 3
    Abstract: Abundantly produced at hadron colliders and appearing as a cluster of energy, jets are the experimental signature of strongly interacting particles. A detailed understanding of jet properties and precise jet calibration are essential for the success of the LHC physics program and becomes increasingly more crucial as more data is collected.  The imminent Run 3 at the LHC paves the way to an era of unprecedented precision.  The knowledge acquired during the previous data-taking periods, both in understanding the detector and in the evolution of analysis strategies, will allow for a calibration accuracy below the per mille level. As a consequence, all CMS physics analyses will profit from the substantial reduction of uncertainties.I will discuss the latest and greatest techniques adopted in CMS for jet calibration, elaborate on the impact on physics analysis and highlight future perspectives in this field.
  • Tuesday 21 February 2023 at 10:15 in A315 and using Zoom: Harri Waltari (Uppsala)
    The anatomy of Higgs pair production with light stops
    The discovery of Higgs pair production is one of the main targets the coming runs of the LHC. In the SM the gluon-initiated process has a destructive interference between the triangle and the box diagrams, which makes Higgs pair production a potential probe of BSM physics. We performed an amplitude-level analysis of Higgs pair production at the LHC in the presence of light stops. We show what types of deviations one could expect and how they arise from different new physics contributions. The toolbox can be used also to different scenarios with additional colored scalars coupling to the Higgs.