Publications

Order by: publication date number of citations

• Recent results on top quark mass and properties and rare/anomalous top quarks interactions in CMS

  Sebastian Wuchterl

  SciPost Phys. Proc. 8, 120 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The amount of data collected by the CMS experiment at the CERN LHC in the second data taking period provides the possibility to study absolute and differential cross sections of top quark interaction processes with high precision. Utilizing these results, fundamental standard model parameters such as the top quark mass are extracted. Moreover, given standard model measurements are interpreted in the context of Beyond the standard model theories. Recent results on top quark properties and rare or anomalous top quark interactions by CMS are presented in these proceedings. Furthermore, the implications of experimental results to effective field theory are discussed.

• Measurements of the Antiquark Flavor Asymmetry in the Proton by the Drell-Yan Experiment SeaQuest

  Kei Nagai

  SciPost Phys. Proc. 8, 119 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The antiquark flavor asymmetry dbar/ubar in the proton gives an insight on the non-perturbative structure of the proton. The SeaQuest experiment measured the Drell–Yan cross section ratio of proton-deuterium to proton-proton to determine the antiquark flavor asymmetry dbar/ubar precisely in the range of 0.13<x<0.45. SeaQuest provides the evidence of dbar/ubar > 1.0 over a wide range of momenta. Some theoretical models reproduce this result.

• EPR and SQUID interrogations of Cr(III) trimer complexes in the MIL-101(Cr) and bimetallic MIL-100(Al/Cr) MOFs

  Kavipriya Thangavel, Andrea Folli, Michael Ziese, Steffen Hausdorf, Stefan Kaskel, Damien M. Murphy, Andreas Pöppl

  SciPost Phys. Proc. 11, 016 (2023) · published 6 June 2023 | Toggle abstract · pdf

  Herein, electron paramagnetic resonance (EPR) spectroscopy at X- (9.4 GHz), Q- (34 GHz) and W-band (95 GHz), and superconducting quantum interference device (SQUID) measurements on antiferromagnetically coupled metal trimers in MIL-101(Cr) and MIL-100(Al$_{0.8}$Cr$_{0.2}$) MOFs were investigated. At low temperatures, the Cr(III) trimers exhibit a Dzyaloshinsky-Moriya (D-M) interaction, and have a total spin state S$_T = 1/2$.

• Two-Loop renormalization of High-Dimensional QCD operators and Higgs EFT amplitudes

  Qingjun Jin, Ke Ren, Gang Yang, Rui Yu

  SciPost Phys. Proc. 7, 036 (2022) · published 21 June 2022 | Toggle abstract · pdf

  We consider two-loop renormalization of high-dimensional operators in QCD and the relevant Higgs EFT amplitudes. Efficient unitarity-IBP strategy is used to compute the two-loop minimal form factors of length-3 operators up to dimension sixteen. From the ultraviolet divergences of form factor results, we extract the renormalization matrices and compute anomalous dimensions. We also obtain the analytic finite remainder functions which exhibit several universal transcendentality structures. The form factors we compute are equivalent to Higgs plus three-gluon amplitudes that capture high-order top mass corrections in Higgs effective field theory.

• Exact physical quantities of a competing spin chain in the thermodynamic limit

  Pengcheng Lu, Yi Qiao, Junpeng Cao, Wen-Li Yang

  SciPost Phys. 15, 060 (2023) · published 10 August 2023 | Toggle abstract · pdf

  We study the exact physical quantities of a competing spin chain which contains many interesting and meaningful couplings including the nearest neighbor, next nearest neighbor, chiral three spins, Dzyloshinsky-Moriya interactions and unparallel boundary magnetic fields in the thermodynamic limit. We obtain the density of zero roots, surface energies and elementary excitations in different regimes of model parameters. Due to the competition of various interactions, the surface energy and excited spectrum show many different pictures from those of the Heisenberg spin chain.

• Remembering David J. Rowe

  John L. Wood, Piet Van Isacker

  SciPost Phys. Proc. 14, 013 (2023) · published 23 November 2023 | Toggle abstract · pdf

  David Rowe was a highly respected theoretical physicist who made seminal contributions that improved our understanding of the atomic nucleus, in particular of the collective behaviour of its constituent nucleons - results he often obtained with the use of sophisticated group-theoretical methods. He will also be remembered as the (co-)author of monographs on nuclear physics, written with the scientific rigour that was characteristic of his research.

• Local investigation of the crystal electric field ground-state in CeCu(Sb,Bi)$_2$ heavy fermions

  Davi Zau, G. S. Freitas, P. G. Pagliuso, R. R. Urbano

  SciPost Phys. Proc. 11, 017 (2023) · published 6 June 2023 | Toggle abstract · pdf

  In this work, we performed systematic Nuclear Magnetic Resonance (NMR) and magnetic susceptibility experiments in CeCuSb$_2$ single-crystals. The main findings were compared to previous report for CeCuBi$_2$. The NMR spectra and transferred hyperfine coupling for the $^{63}$Cu nuclei were obtained aiming to observe their correlation with the crystal electric field (CEF) effects on the Ce$^{3+}$ ($J=5/2$) multiplet. Besides, in an attempt to elucidate the magnetic structure through NMR measurements at different magnetic fields orientations, we observed a magnetic transition at $T\approx 8\,$K higher than the Néel temperature $T_N$ measured by magnetic susceptibility indicating the development of short-range magnetic ordering above T$_N$. In addition, the wipe out of the main NMR resonance line and a persistent spin-echo signal throughout the whole frequency-swept range suggest the possibility of an incommensurate magnetic structure in CeCuSb$_2$. Furthermore, the small transferred hyperfine coupling constant found for CeCuSb$_2$ indicates a scenario with more localized Ce$^{3+}$ 4f electrons than for CeMIn$_5$ (M $=$ Co,Rh,Ir) heavy fermions family. Additionally, subtle changes in the hybridization between the $^{63}$Cu with the 4f$^1$ Ce$^{3+}$ electrons in distinct magnetic field orientations allowed us to provide detailed information and map out the 4f CEF orbital ground-state of CeCu(Sb,Bi)$_2$ via NMR measurements.

• Applications of the Perturbative Gradient Flow

  Fabian Lange

  SciPost Phys. Proc. 7, 033 (2022) · published 21 June 2022 | Toggle abstract · pdf

  Over the last decade the gradient flow formalism became an important tool for lattice simulations of Quantum Chromodynamics. It offers remarkable renormalization properties which pave the way for cross-fertilization between perturbative and lattice calculations. In this contribution we discuss the perturbative approach. As first application we compute vacuum expectation values of flowed operators which could help to extract parameters like the strong coupling constant from lattice simulations. Afterwards, we apply the flowed operator product expansion to the time-ordered product of two currents which could be employed for an alternative first-principle evaluation of vacuum polarization functions on the lattice.

• Self-binding of one-dimensional fermionic mixtures with zero-range interspecies attraction

  Jules Givois, Andrea Tononi, and Dmitry S. Petrov

  SciPost Phys. 14, 091 (2023) · published 3 May 2023 | Toggle abstract · pdf

  For sufficiently large mass ratios the attractive exchange force caused by a single light atom interacting with a few heavy identical fermions can overcome their Fermi degeneracy pressure and bind them into an $N+1$ cluster. Here, by using a mean-field approach valid for large $N$, we find that $N+1$ clusters can attract each other and form a self-bound charge density wave, the properties of which we fully characterize. Our work shows that there are no fundamental obstacles for having self-bound states in fermionic mixtures with zero-range interactions.

• Ergodic Archimedean dimers

  Henrik Schou Røising, Zhao Zhang

  SciPost Phys. Core 6, 054 (2023) · published 11 August 2023 | Toggle abstract · pdf

  We study perfect matchings, or close-packed dimer coverings, of finite sections of the eleven Archimedean lattices and give a constructive proof showing that any two perfect matchings can be transformed into each other using small sets of local ring-exchange moves. This result has direct consequences for formulating quantum dimer models with a resonating valence bond ground state, i.e., a superposition of all dimer coverings compatible with the boundary conditions. On five of the composite Archimedean lattices we supplement the sufficiency proof with translationally invariant reference configurations that prove the strict necessity of the sufficient terms with respect to ergodicity. We provide examples of and discuss frustration-free deformations of the quantum dimer models on two tripartite lattices.