Grad School Physics Seminar 2024/25

Europe/Warsaw
Room 207 (NCBJ)

Room 207

NCBJ

Pasteura 7
Anna Durkalec (National Centre for Nuclear Research), Jakub Wagner (National Centre for Nuclear Research), Michal Bluj (NCBJ)
Description

Physics seminar of the Graduate School of NCBJ.

GoToMeeting link for the seminar: https://app.gotomeeting.com/?meetingId=434622613

    • 09:15 09:35
      Welcoming Talk of the Graduate School Director 20m
      Speaker: Prof. Michał Spaliński
    • 09:35 09:55
      Discussion about the goals and organization of the PhD seminar 20m
      Speakers: Anna Durkalec (National Centre for Nuclear Research), Jakub Wagner (National Centre for Nuclear Research), Michal Bluj (NCBJ)
    • 09:15 10:00
      Multidimensional Random Walk for Calculating the Fusion/Fission Probabilities of Superheavy Elements 45m

      In our recent work [1], we introduced a novel approach, the Dipole-Driven Model (DDM), for characterizing the fusion process of two heavy ions within the entrance channel. The DDM utilizes the dipole variable as an authentic shape parameter to describe the configuration of the colliding heavy ions, with shape parametrization performed at the neck region. This allows for the optimization of the deformation space and the exploration of previously unattainable shapes.
      In this talk, a new method for predicting the probability of fusion of superheavy elements will be presented. The approach uses a random walk algorithm, in which the shape evolution is governed by the density of states above the multidimensional potential energy surface (PES). The PESs were calculated within the latest version of the Warsaw macroscopic-microscopic model [1], with rotational energy included.
      Three cold fusion reactions will be examined in detail: 48Ca+208Pb, 50Ti+208Pb and 54Cr+208Pb. The calculated probabilities of fusion for these reactions will be shown. The influence of angular momentum and excitation energy on ratios of symmetric and asymmetric divisions will be demonstrated. Future improvements to the method will also be discussed.

      [1] T. Cap, A. Augustyn, M. Kowal, and K. Siwek-Wilczyńska, Phys. Rev. C 109, L061603 (2024).
      [2] P. Jachimowicz, M. Kowal, and J. Skalski, At. Data. Nucl. Data. Tables. 138, 101393 (2021).

      Speaker: Mr Aleksander Augustyn (NCBJ)
    • 10:00 10:20
      Cancelled 20m
    • 09:15 10:00
      Understanding the Vector Boson Scattering at the CMS experiment at CERN 45m

      In this seminar, I will present a study of Vector Boson Scattering (VBS) processes at the Compact Muon Solenoid (CMS) experiment at CERN, with a specific focus on the scattering of same-sign W bosons. The final state under investigation involves two leptons, two neutrinos and two tagging jets. My analysis will explore key VBS processes, detailing the challenges posed by various backgrounds and the strategies employed to mitigate their contributions. In particular, I will highlight the impact of non-prompt leptons, which represent one of the most significant backgrounds, and explain how these are addressed in our study. Additionally, I will share insights from the data analysis, including results related to the interpretation within the framework of the Standard Model Effective Field Theory (SMEFT).

      Speaker: Monika Ghimiray
    • 09:15 10:15
      Evolution of the ISM in quiescent galaxies 1h

      Unveiling the routes galaxies take to quiescence is one of the most open challenges in galaxy evolution. While the most of studies focused on characterizing quiescent galaxies (QG) across cosmic time through their stellar properties using optical/near-infrared (NIR) data, the mid-infrared regime was only recently examined thanks to the advent of JWST. The need to understand the MIR emission in QGs has been emphasized due to recent discoveries of a peculiar population of quiescent, but dust-rich galaxies at high-redshitts (z>0.5-3). In this talk, I will present the preliminary results of a first study that investigated the quenching routes and the physical properties of MIRI-bright, dust-attenuated QGs in the distant universe.

      Speaker: Krzysztof Lisiecki (NCBJ BP4)
    • 09:15 10:15
      Microlensing of continuous gravitational waves 1h

      The direct detection of gravitational waves (GWs) by the LIGO Science Collaboration marked the beginning of a new era in astronomy, allowing us to probe previously inaccessible realms of the universe. Among the most exciting prospects in this field is the detection of gravitationally lensed GWs, which could reveal valuable insights about intervening mass distributions in space. While much attention has focused on detecting lensing in GWs from merging compact binaries, little exploration has been directed toward the lensing of GWs emitted by isolated neutron stars. These GWs are continuous and monochromatic, differing significantly from the transient "chirp" signals we typically observe. In this talk, I will discuss our findings on the lensing of continuous GWs by dark mini-halos and demonstrate how the relative motion between the lens, source, and observer can produce a distinctive microlensing pattern. This work opens new avenues in the study of GW lensing and could provide unique insights into the nature of dark matter besides enhancing the detectability of a signal.

      Speaker: Sreekanth Harikumar (National Centre for Nuclear Research(NCBJ))
    • 09:15 10:15
      Neutrinophillic scalar detection prospects at a future muon collider 1h

      In the upcoming muon collider, high-energy collisions between muons and antimuons will reach center-of-mass energies up to 10 TeV. Decays of these muons in the beam pipe will produce a high-energy muon neutrino beam. The energy and intensity of the beam, as well as its well-known energy spectrum, provide a unique opportunity to study neutrino properties and interactions, potentially uncovering new physics beyond the Standard Model.

      In this talk, I will discuss the prospects for detecting new mediators that couple predominantly to neutrinos with masses in the 1 MeV to 100 GeV range with low coupling strengths. Such a neutrinophillic mediator, which could couple to the dark sector, is a well-motivated candidate for opening new avenues in the search for neutrino portal dark matter. The corresponding signature would include neutrino charged-current scattering events associated with positively charged muons.

      Speaker: Jyotismita Adhikary (NCBJ)
    • 09:15 10:15
      Nuclear chirality as a part of nuclear physics 1h

      Nuclear chirality, a phenomenon known for only 27 years, is being found in more and more different nuclei, around 60 isotopes found to date. Nuclear chirality can occur in the excited state when the nuclei is triaxially deformed.

      In this seminar, I will show why and how we examine excited states in nuclei, what is the nuclear chirality, and how it can be found. I will also show the final results of the experiment performed in July 2022 at Heavy Ion Laboratory in Warsaw and state the most important outcomes.

      Speaker: Adam Nałęcz-Jawecki (NCBJ)
    • 09:15 10:15
      Galactic foreground bias in CMB lensing reconstruction 1h

      Weak gravitational lensing remaps the primordial anisotropies in the Cosmic Microwave Background (CMB), contaminating the measurements of cosmological parameters. Estimating the lensing potential field and delensing the CMB maps of high sensitivity experiments are crucial for improving cosmological measurements. However, one of the main obstacles for these tasks is the presence of foreground emissions from our own Galaxy. In this talk, I will discuss about CMB weak lensing reconstruction methods and the impact of galactic foreground emissions. I will present my results on galactic foreground bias in the context of upcoming CMB Stage-4 survey.

      Speaker: Mr Kishan Deka (NCBJ (BP4))
    • 09:15 10:15
      Cancelled due to the Annual Reporting Seminar 1h
    • 09:15 10:15
      Asymptotically safe gravity as a guiding light to particle phenomenology 1h

      Compelling evidence suggests the existence of new physics beyond the Standard Model. However, in the absence of new experimental data, the energy scales associated with this new physics remain unknown. In this talk, I will give an overview of how the asymptotic safety paradigm can offer insights into these unknowns, addressing several of the outstanding puzzles and challenges within the Standard Model. Specifically, I will discuss how the presence of a specific fixed point structure in the renormalization group flow of model parameters—induced by gravitational corrections above the Planck scale—has several interesting implications. Firstly, I will discuss how this framework could lead to predictions of the new-physics couplings in U(1)’ extensions of the Standard Model. As a second example, I will discuss how this paradigm could give rise to a dynamical mechanism to generate small neutrino masses in the gauged B-L extension and its phenomenological signatures. Finally, I will demonstrate how asymptotically safe gravity can make a measurable contribution to the SMEFT coefficients, challenging the expectation that such contributions are suppressed by the Planck scale.

      Speaker: Mr Abhishek Chikkaballi
    • 09:15 10:15
      Search for signatures of physics beyond the Standard Model in vector boson scattering processes at the CMS experiment at LHC 1h

      Vector Boson Scattering (VBS) is essential for understanding electroweak symmetry breaking and testing the Standard Model at high energies. At the LHC, the CMS experiment investigates VBS processes to identify potential deviations, such as anomalous quartic gauge couplings (aQGCs), which could hint at new physics, including undiscovered particles or interactions. This project focuses on the scattering of two same-sign W bosons, producing two same-sign leptons, neutrinos, and two jets. For this analysis, we used a subset of Run 3 data from 2022, corresponding to an integrated luminosity of 27 fb⁻¹. Background estimation incorporates both Monte Carlo (MC) simulations and a data-driven approach for non-prompt backgrounds.

      Speaker: Mohammad Mousavi
    • 09:15 10:15
      Exploring Graviton Mass through Strongly Lensed Gravitational Waves 1h

      Recent advancements in time-domain surveys have significantly increased the detection of various explosive transient events across the universe, including supernovae, gamma-ray bursts, fast radio bursts, and gravitational waves (GWs). Some of these events can manifest as multiple images due to gravitational lensing. While numerous strongly lensed distant galaxies and quasars have been cataloged, the strong lensing of explosive transients offers new scientific possibilities. These opportunities range from refining measurements of cosmological parameters and detecting dark matter, to testing fundamental physics. Particularly, the long wavelengths of GWs suggest that wave optics effects are crucial in some instances, potentially leading to novel uses of these lensing phenomena. With the next generation of GW detectors expected to enhance sensitivity tenfold, the observable volume of the universe could expand by a thousandfold, substantially increasing detection rates of lensed GW signals. This surge in data provides a unique platform to examine critical physical theories, such as the properties of gravitons, by studying strongly lensed gravitational waves.
      In this work, we investigate constraints on the graviton mass by analyzing strongly lensed GW signals from typical binary black hole mergers. We simulate the response of next-generation ground-based GW detectors, such as the Einstein Telescope, to better gauge the potential of upcoming observations. Our analysis assesses the capacity of future GW data to place meaningful constraints on graviton mass, thereby offering fresh perspectives on the nature of gravity at cosmic scales. This study underscores the critical role of gravitational lensing in enhancing GW astronomy's capability to address fundamental physics questions, with broad implications for our understanding of the universe's fundamental structure

      Speaker: Shuaibo Geng (National Center for Nuclear Research)
    • 09:15 10:15
      Precision calculations for high energy scattering: SIDIS and Inclusive DIS at next-to-eikonal order 1h

      Studying high-energy hadronic scattering processes to understand the structure of nuclei has been the focus of experimental and theoretical studies for more than three decades now. The Color Glass Condensate (CGC) effective theory has been developed and used to study particularly high-energy dilute-dense collisions. One of the main approximations adopted in the Color Glass Condensate is the so-called eikonal approximation, which amounts to neglecting power-suppressed corrections in the high-energy limit. This approximation is well justified for asymptotically high energies. However, corrections to it might be sizable in practice, in particular at the Relativistic Heavy Ion Collider and the upcoming Electron-Ion Collider. Therefore, we need to bring precision in theory to analyze the upcoming data from the colliders. For this, we have to compute observables like scattering cross sections beyond the leading order of energy. Deep inelastic scattering (DIS) is one of the clean channels used to study CGC beyond eikonal order.
      In my talk, I will briefly review the eikonal approximation and how to go beyond eikonal order. Furthermore, I will present its application to semi-inclusive deep inelastic scattering (SIDIS) and Inclusive DIS. Specifically, I will present computations of new contributions to the cross-section of SIDIS at next-to-eikonal accuracy stemming from the t-channel quark exchange, by including the effect of the quark background field for the target and obtain its relation to Transverse momentum dependent (TMD) calculations in small-x limit. I will also present similar studies for inclusive DIS.

      Speaker: Swaleha Mulani (National Centre for Nuclear Research(NCBJ), Warsaw, Poland)
    • 09:15 10:15
      Sushobhan Mandal's seminar 1h

      To be written

      Speaker: Sushobhan Mandal (NCBJ)
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