Seminar

There will be a JBNU HEP-COSMO seminar (in person) on June 10th (Friday) from 12:00 - 14:00 in room 217.Dr. Yu Seon Jeong in Chung Ang U. will be visiting JBNU from June 9th - 10th and give an in-person seminar with the following title and abstract. Title: Forward neutrinos at the LHC Abstract: Two forward experiments, FASER$\nu$ and SND@LHC are scheduled during the Run 3 at the LHC and the new experiment, Forward Physics Facility was proposed for the High-Luminosity LHC stage. These experiments will probe neutrinos at high rapidity region, the fluxes of which are sensitive to QCD dynamics of heavy flavor production and have not yet been measured. In this talk, I will introduce the forward experiments at the LHC and discuss the expected fluxes and events of neutrinos that are produced from charm hadrons. In addition, I will present some neutrino related physics potential at the forward experiments at the LHC.

Time: 5:30 PM, Apr 20th (Wed) 2022Venue: Room 204, Natural Science Building #5Speaker: Donghui Jeong (Department of Astronomy and Astrophysics, Pennsylvania State University)Title: Gravitational Wave, CMB Polarization, and Hubble TensionAbstract: The discrepancy between the Hubble parameter inferred from local measurements and that from the cosmic microwave background (CMB) has motivated careful scrutiny of the assumptions that enter both analyses. Here we point out that the location of the recombination peak in the CMB B-mode power spectrum is determined by the light horizon at the surface of last scattering and thus provides an alternative early-Universe standard ruler. It can thus be used as a cross-check for standard ruler inferred from the acoustic peaks in the CMB temperature power spectrum and to test various explanations for the Hubble tension. The measurement can potentially be carried out with a precision = 2% with state-IV B-mode experiments. The measurement can also be used to measure the propagation speed of gravitational waves in the early Universe.

There will be HEP joint seminars in person this Friday (April 15th) in room 418.The speakers are Dr. Jongkuk Kim and Dr. Dong Woo Kagn from KIAS.Here is the detailed information.강의실: 전북대학교 자연과학대학 5호관 418호13:00 - 14:00 Jongkuk KimTitle: Muon g-2 and thermal WIMP DM in L_\mu - L_\tau models Abstract: U(1)L L U(1)X model is anomaly free within the Standard Model (SM) fermion content, and can accommodate the muon (g 2) data for MZ O(10 100) MeV and gX (4 8) 10 4. WIMP type thermal dark matter (DM) can be also introduced for MZ 2MDM, if DM pair annihilations into the SM particles occur only through the s-channel Z exchange. In this work, we show that this tight correlation between MZ and MDM can be completely evaded both for scalar and fermionic DM, if we include the contributions from dark Higgs boson. Dark Higgs boson plays a crucial role in DM phenomenology, not only for generation of dark photon mass, but also opening new channels for DM pair annihilations into the final states involving dark Higgs boson, such as dark Higgs pair as well as Z Z through dark Higgs exchange in the s-channel, and co-annihilation into Z H1 in case of inelastic DM. Thus dark Higgs boson will dissect the strong correlation MZ 2MDM, and much wider mass range is allowed for U(1)X-charged complex scalar and Dirac fermion DM, still explaining the muon (g 2). We consider both generic U(1)X breaking as well as U(1)X Z2 (and also into Z3 only for scalar DM case).14:30 - 15:30 Dong Woo KangTitle: Reconstruct Missing Energy Event Kinematics with Deep Neural NetworkAbstract: We present a deep learning technique for building an optimal searching for events with missing kinematic information at the colliders. It can be usefully used for precise measurement of the standard model or to find new physics beyond the standard model in events involving neutrino or dark matter. To be specific, we reconstruct the invisible momenta in tt-like antler event topology and reconstruct the particle mass spectrum of the event. The method using deep learning is closely related to the algebraic singularity and solvability of the kinematics. We show the connection between algebraic singularity and solvability of the kinematics and our method can be explained as an extension of it.

https://sites.google.com/view/kias-particlepheno-jc/seminar?authuser=0

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