Publications

Order by: publication date number of citations

• The SU(2)$_{D}$ lepton portals for muon g - 2, W boson mass and dark matter

  Seong-Sik Kim, Hyun Min Lee, Adriana Guerrero Menkara, Kimiko Yamashita

  SciPost Phys. Proc. 12, 045 (2023) · published 4 July 2023 | Toggle abstract · pdf

  We propose a novel model which extends the Standard Model (SM) by introducing a $SU(2)_D$ gauge symmetry. In this model, a dark $SU(2)_D$ Higgs doublet and a Higgs bi-doublet can contribute to the muon g-2 anomaly and the $W$ boson mass, remaining in tune with the recent experimental results. At the same time, the isospin charged gauge boson of $SU(2)_D$ becomes a plausible candidate for Dark Matter(DM). We find that the resulting parameter space can fit the muon g-2, the W boson mass and the DM constraints simultaneously.

  1 citation

• A new derivation of the relationship between diffusion coefficient and entropy in classical Brownian motion by the ensemble method

  Yi Liao, Xiao-Bo Gong

  SciPost Phys. Core 4, 015 (2021) · published 2 June 2021 | Toggle abstract · pdf

  The diffusion coefficient--a measure of dissipation, and the entropy--a measure of fluctuation are found to be intimately correlated in many physical systems. Unlike the fluctuation dissipation theorem in linear response theory, the correlation is often strongly non-linear. To understand this complex dependence, we consider the classical Brownian diffusion in this work. Under certain rational assumption, i.e. in the bi-component fluid mixture, the mass of the Brownian particle $M$ is far greater than that of the bath molecule $m$, we can adopt the weakly couple limit. Only considering the first-order approximation of the mass ratio $m/M$, we obtain a linear motion equation in the reference frame of the observer as a Brownian particle. Based on this equivalent equation, we get the Hamiltonian at equilibrium. Finally, using canonical ensemble method, we define a new entropy that is similar to the Kolmogorov-Sinai entropy. Further, we present an analytic expression of the relationship between the diffusion coefficient $D$ and the entropy $S$ in the thermal equilibrium, that is to say, $D =\frac{\hbar}{eM} \exp{[S/(k_Bd)]}$, where $d$ is the dimension of the space, $k_B$ the Boltzmann constant, $\hbar $ the reduced Planck constant and $e$ the Euler number. This kind of scaling relation has been well-known and well-tested since the similar one for single component is firstly derived by Rosenfeld with the expansion of volume ratio.

  1 citation

• Higgs phases and boundary criticality

  Kristian Tyn Kai Chung, Rafael Flores-Calderón, Rafael C. Torres, Pedro Ribeiro, Sergej Moroz, Paul McClarty

  SciPost Phys. 19, 105 (2025) · published 21 October 2025 | Toggle abstract · pdf

  Motivated by recent work connecting Higgs phases to symmetry protected topological (SPT) phases, we investigate the interplay of gauge redundancy and global symmetry in lattice gauge theories with Higgs fields in the presence of a boundary. The core conceptual point is that a global symmetry associated to a Higgs field, which is pure-gauge in a closed system, acts physically at the boundary under boundary conditions which allow electric flux to escape the system. We demonstrate in both Abelian and non-Abelian models that this symmetry is spontaneously broken in the Higgs regime, implying the presence of gapless edge modes. Starting with the U(1) Abelian Higgs model in 4D, we demonstrate a boundary phase transition in the 3D XY universality class separating the bulk Higgs and confining regimes. Varying the boundary coupling while preserving the symmetries shifts the location of the boundary phase transition. We then consider non-Abelian gauge theories with fundamental and group-valued Higgs matter, and identify the analogous non-Abelian global symmetry acting on the boundary generated by the total color charge. For $\mathrm{SU}{N}$ gauge theory with fundamental Higgs matter we argue for a boundary phase transition in the $\mathrm{O}{2N}$ universality class, verified numerically for $N=2,3$. For group-valued Higgs matter, the boundary theory is a principal chiral model exhibiting chiral symmetry breaking. We further demonstrate this mechanism in theories with higher-form Higgs fields. We show how the higher-form matter symmetry acts at the boundary and can spontaneously break, exhibiting a boundary confinement-deconfinement transition. We also study the electric-magnetic dual theory, demonstrating a dual magnetic defect condensation transition at the boundary. We discuss some implications and extensions of these findings and what they may imply for the relation between Higgs and SPT phases.

  1 citation

• Correlations among 3N observables

  Yuriy Volkotrub, Jacek Golak, Roman Skibiński, Kacper Topolnicki, Henryk Witała

  SciPost Phys. Proc. 3, 055 (2020) · published 27 February 2020 | Toggle abstract · pdf

  We use a correlation matrix of two-nucleon (2N) potential parameters to investigate correlations among three-nucleon (3N) observables for the elastic nucleon-deuteron (Nd) scattering process. We employ the up-to-date 2N semilocal momentum-space regularized chiral interactions and the phenomenological OPE-Gaussian potential and using the Faddeev formalism we calculate 3N observables and their correlations. As an example, we present the correlation between the differential cross section and the deuteron analyzing power T20.

  1 citation

• Can quantized fragmentation replace colour reconnection models?

  Šárka Todorova-Nová

  SciPost Phys. Proc. 15, 001 (2024) · published 2 April 2024 | Toggle abstract · pdf

  A brief overview of properties of the model of quantized fragmentation of a helical QCD string is followed by the discussion of colour reconnection models and of the ways to reproduce the evolution of the average transverse momentum in hadronic events, as function of charged particle multiplicity. Reference to recent experimental data is included.

  1 citation

• MACK: Mismodeling addressed with contrastive knowledge

  Liam Rankin Sheldon, Dylan Sheldon Rankin, Philip Harris

  SciPost Phys. 18, 150 (2025) · published 6 May 2025 | Toggle abstract · pdf

  The use of machine learning methods in high energy physics typically relies on large volumes of precise simulation for training. As machine learning models become more complex they can become increasingly sensitive to differences between this simulation and the real data collected by experiments. We present a generic methodology based on contrastive learning which is able to greatly mitigate this negative effect. Crucially, the method does not require prior knowledge of the specifics of the mismodeling. While we demonstrate the efficacy of this technique using the task of jet-tagging at the Large Hadron Collider, it is applicable to a wide array of different tasks both in and out of the field of high energy physics.

  1 citation

• Preference for Chaudfontaine or bias towards the preferred option?

  Alexandra Sarafoglou

  J. Robust. Rep. 0-Ex2 (2025) · published 16 April 2025 | Toggle abstract · pdf

  Although participants' taste scores were influenced by their preferences, they still generally favored Chaudfontaine over tap water, which confirms the original claim.

  1 citation

• Searching for wave-like dark matter with QSHS

  Ian Bailey, Bhaswati Chakraborty, Gemma Chapman, Edward J. Daw, John Gallop, Gianluca Gregori, Edward Hardy, Ling Hao, Edward Laird, Peter Leek, John March-Russell, Phil Meeson, Seaárbhan Ó Peatáin, Yuri Pashkin, Mitchell G. Perry, Michele Piscitelli, Edward Romans, Subir Sarkar, Paul J. Smith, Ningqiang Song, Mahesh Soni, Boon K. Tan, Stephen West, Stafford Withington

  SciPost Phys. Proc. 12, 040 (2023) · published 4 July 2023 | Toggle abstract · pdf

  In 2021 the Quantum Sensors for the Hidden Sector (QSHS) collaboration was founded in the UK and received funding to develop and demonstrate quantum devices with the potential to detect hidden sector particles in the $\mu$eV to 100 $\mu$eV mass window. The collaboration has been developing a range of devices. It is building a high-field, low-temperature facility at the University of Sheffield to characterise and test the devices in a haloscope geometry. This paper introduces the collaboration's motivation, aims, and progress.

  1 citation

• Muon Decay

  W. Fetscher

  SciPost Phys. Proc. 5, 006 (2021) · published 6 September 2021 | Toggle abstract · pdf

  The decay of the muon has been studied at PSI with several precision measurements: The longitudinal polarization PL(E) with the muon decay parameters ξ′, ξ′′, the Time- Reversal Invariance (TRI) conserving transverse polarization PT1(E) with the muon de- cay parameters η, η′′, the TRI violating transverse polarization PT2(E), with α′/A, β′/A and the muon decay asymmetry with Pμξ. The detailed theoretical analysis of all mea- surements of normal and inverse muon decay has led for the first time to a lower limit |g V | > 0.960 ("V − A") and upper limits for nine other possible complex couplings, espe- cially the scalar coupling |g S | < 0.550 which had not been excluded before.

  1 citation

• Anyon condensation in mixed-state topological order

  Ken Kikuchi, Kah-Sen Kam, Fu-Hsiang Huang

  SciPost Phys. Core 8, 072 (2025) · published 20 October 2025 | Toggle abstract · pdf

  We discuss anyon condensation in mixed-state topological order. The phases were recently conjectured to be classified by pre-modular fusion categories. Just like anyon condensation in pure-state topological order, a bootstrap analysis shows condensable anyons are given by connected étale algebras. We explain how to perform generic anyon condensation including non-invertible anyons and successive condensations. Interestingly, some condensations lead to pure-state topological orders. We clarify when this happens. We also compute topological invariants of equivalence classes.

  1 citation