Publications

2025

The Cosmological Constant and Dark Dimensions from Non-Supersymmetric Strings
- Dudas Emilian
- Parameswaran Susha
- Serra Marco
, 2025. 46 pages, 4 figures, 4 appendices
Living on the edge: radius effects in the angular substructure of heavy-ion jets
- Andres Carlota
- Holguin Jack
- Kimelman Benjamin
- Kunnawalkam Elayavalli Raghav
- Viinikainen Jussi
- Yang Zhong
, 2025. Jet substructure observables serve as essential tools for probing the quark-gluon plasma produced in relativistic heavy-ion collisions. Their interpretation, however, is often complicated by edge effects, which arise when correlated particles fall outside the reconstructed jet radius, introducing distortions that obscure the underlying QCD dynamics. In this work, we present a comprehensive phenomenological study of edge effects in soft-insensitive angular observables, taking the two-point energy correlator (EEC) as a representative example. We argue that these distortions scale linearly with the average angular separation between the winner-take-all and $E$-scheme axes $\langle ϕ\rangle$, and validate this behavior across proton-proton (p-p) simulations with Pythia8 and Herwig7, as well as lead-lead (Pb-Pb) simulations using JEWEL and CoLBT. In p-p collisions, edge effects are strongly suppressed, scaling as $(R_L/R)^4$, whereas medium-modified jets can exhibit larger distortions, with contributions scaling as $(R_L/R)^2$ and $(R_L/R)^4$. Taking Pb-Pb/p-p ratios of the EEC substantially reduces, but does not completely eliminate, these distortions, highlighting the need of accounting for edge effects in the interpretation of heavy-ion jet substructure measurements. Since edge effects are largely governed by the $\langle ϕ\rangle$ distribution, studying this distribution provides a new handle for benchmarking and constraining the modeling of edge effects in heavy-ion event generators.
investigating strongly correlated materials with modern numerical tools : from dynamical mean-field theory to tensor trains
- Rampon Liam
, 2025. This thesis is concerned with the development of numerical methods for strongly correlated materials, which include unconventional superconductors and Mott insulators.We first investigate spiral magnetic ordering in a model strongly correlated system by mapping the latticeto a self-consistent impurity model. We obtain a phase diagram and identify the magnetization mechanism.The main improvements would be to enlarge the impurity model, and to solve it in real instead of imaginary time. In a second part, we apply tensor cross-interpolation(TCI) to accelerate the computation of Keldysh perturbative expansions. TCI is a new compression technique, able to separate the variables of a function.We compute real time propagators on impurity models with state-of-the-art or above precision and anotable speedup. In the process, we highlight theuse of Koornwinder polynomials for interpolation on a simplex. Further research is needed for extending to multi-site impurities and lattices.
Three-dimensional imaging of hadrons with hard exclusive reactions: advances in experiment, theory, phenomenology, and lattice QCD
- Boër M.
- Camsonne A.
- Constantinou M.
- Jo H.S.
- Joo K.
- Semenov-Tian-Shansky K.
- Son H.-D.
- Sznajder P.
- van Hulse C.
- Wagner J.
- Afanasev A.
- Alvarado J.S.
- Bhattacharya S.
- Biswas D.
- Cao Xu
- Choi H.-M.
- Cichy K.
- Crnković N.
- Hamdi W.
- Hoballah M.
- Huber G.M.
- Hutauruk P. T. P.
- Jentsch A.
- Ji C.-R.
- Kim H.-Ch.
- Kriesten B.
- Lin Huey-Wen
- Lin P. -J.
- Martínez-Fernández V.
- Mazouz M.
- Meziani Z.-E.
- Nefedov M.
- Passek-K. K.
- Pire B.
- Rossi P.
- Teryaev O.
- Thomas A. W.
- Tomida N.
EPJA, 2025. 113 pages, 68 figures, white paper of the workshops "3D Structure of the Nucleon via Generalized Parton Distributions'', Incheon, Republic of Korea, June 25-28, 2024, and "Towards improved hadron tomography with hard exclusive reactions'', ECT*-Trento, Italy, August 5-9, 2024
Deep-lying semi-Dirac fermions in hexagonal close-packed cadmium
- Subedi Alaska
- Behnia Kamran
, 2024. Semi-Dirac fermions are massless in one direction and massive in the perpendicular directions. Such quasiparticles have been proposed in various contexts in condensed matter. Using first principles calculations, we identify a pair of semi-Dirac bands anti-crossing at $-3$ eV below the Fermi level in the electronic structure of hexagonal close-packed cadmium. The linear out-of-plane dispersion is kept up to the Fermi level. We demonstrate that the dichotomy between the linear and quadratic dispersions is driven by an orientation-sensitive hybridization between the $s$ and $p_z$ orbitals. The upper semi-Dirac band produces a lens-shaped nonellipsoidal Fermi sheet whose cross-section area has a $k$-dependence that is in excellent agreement with the experimentally measured period of Sondheimer oscillations.
Pressure-tunable structural instabilities in single-layer-trilayer La$_3$Ni$_2$O$_7$
- Subedi Alaska
, 2024. Layered nickelates are believed to exhibit superconductivity similar to that found in the cuprates. However, the precise crystal structure of the superconducting phase of the layered nickelates has not been fully clarified. Here, I use first principles calculations to study the pressure dependence of the structural instabilities in the single-layer-trilayer La$_3$Ni$_2$O$_7$, which is one member of the layered nickelates family that also shows signatures of superconductivity. I find a nearly dispersionless nondegenerate phonon branch in the parent $P4/mmm$ phase that is unstable along the Brillouin zone edge $M$ $(\frac{1}{2}, \frac{1}{2}, 0)$ $\rightarrow$ $A$ $(\frac{1}{2},\frac{1}{2},\frac{1}{2})$ at all investigated pressures up to 30 GPa. Calculations show additional doubly-degenerate instabilities along the edge $MA$ at lower pressures. I used group-theoretical analysis to identify the distinct low-symmetry distortions possible due to these instabilities and generated them using the eigenvectors of the unstable modes. Structural relaxations show that the lowest energy structures at 0 and 10 GPa involve condensation of both the nondegenerate and doubly-degenerate instabilities, which is in contrast to the experimental refinements that involve condensation of only the doubly-degenerate branch. I also find that structural distortions are energetically favorable at 20 GPa, contrary to the experiments that do not observe any distortions of the parent $P4/mmm$ structure at high pressures.
Optimizing unitary coupled cluster wave functions on quantum hardware: Error bound and resource-efficient optimizer
- Plazanet Martin
- Ayral Thomas
The Journal of Chemical Physics, American Institute of Physics, 2025, 163 (21). In this study, we study the projective quantum eigensolver (PQE) approach, a hybrid quantum–classical algorithm that, by optimizing a unitary coupled cluster wave function, aims at computing the ground state of many-body systems. Instead of trying to minimize the energy of the system like the variational quantum eigensolver (VQE), PQE uses projections of the Schrödinger equation to efficiently bring the trial state closer to an eigenstate of the Hamiltonian. In this study, we provide a mathematical study of the algorithm. We derive a bound relating off-diagonal coefficients (residues) of the Hamiltonian to the energy error of the algorithm and the overlap achieved by the obtained wavefunction. These bounds not only give formal guarantees to PQE, but they also allow us to formulate a well-informed convergence criterion for residue-based optimizers. We then study the classical optimization itself and derive convergence guarantees under certain conditions. We propose a new residue-based optimizer, with numerical evidence of the superiority of this new approach for H4, H6, BeH2, and LiH dissociation curves over both the optimization introduced in Stair and Evangelista [PRX Quantum 2, 030301 (2021)] and VQE optimized using the Broyden–Fletcher–Goldfarb–Shanno method. (10.1063/5.0299885)
DOI : 10.1063/5.0299885
Perturbative and nonperturbative analysis of the renormalisation group equations
- Wang Pierre
, 2025. This thesis focuses on a non-perturbative and perturbative analysis of the renormalization group flow equations. We analyze the real scalar massive theory with a quartic interaction in four dimensions in the mean-field approximation. First we tackled the triviality problem of the mean-field theory. Using the mean-field non-perturbative flow equations, we constructed, for arbitrary bare couplings, mean-field trivial solutions. In order to simplify the study, we made the technical assumption of a zero mass propagator. To prove the uniqueness of the mean-solutions for fixed mean-field boundary conditions, we derived an integral formulation of the mean-field flow equations. Then, we used our method to analyze the O(N)-model in which the field has N scalar components. Again we proved the triviality result. Then, we dropped our technical assumption on the mass of the regularized propagator in momentum space, it turns out that the triviality result remains valid. In a second part, we confronted our trivial solutions to perturbation theory. We proved that under an ultraviolet regularization, our mean-field solutions have a perturbative expansion in a suitably chosen renormalized coupling. We show that the local Borel transform of the corresponding regularized renormalized mean-field perturbation theory exists and is asymptotic to the non-perturbative mean-field theory. Finally we prove the local Borel summability of the regularized renormalized mean-field perturbation theory. (10.70675/06f3b3b9z52ecz493czb0c6z516ba31fd722)
DOI : 10.70675/06f3b3b9z52ecz493czb0c6z516ba31fd722
Non-Linear Supergravity and Inflationary Cosmology
- Antoniadis Ignatios
- Dudas Emilian
- Farakos Fotis
- Sagnotti Augusto
, 2024. 27 pages, 1 figure. Invited contribution to "Half a century of Supergravity'', eds. A. Ceresole and G. Dall'Agata (Cambridge Univ. Press, to appear)
Conceptual design report of the Super Tau-Charm Facility: the accelerator
- Ai Xiao-Cong
- An Liu-Pan
- An Shi-Zhong
- Bai Yu
- Bai Zheng-He
- Bakina Olga
- Bao Jian-Cong
- Batozskaya Varvara
- Belias Anastasios
- Biagini Maria Enrica
- Bian Li-Gong
- Bodrov Denis
- Bogomyagkov Anton
- Boscolo Manuela
- Boyko Igor
- Cao Ze-Xin
- Cetin Serkant
- Chadeeva Marina
- Chang Ming-Xuan
- Chang Qin
- Chen Dian-Yong
- Chen Fang-Zhou
- Chen Hai
- Chen Hua-Xing
- Chen Jin-Hui
- Chen Long
- Chen Long-Bin
- Chen Qi
- Chen Qu-Shan
- Chen Shao-Min
- Chen Wei
- Chen Ying
- Chen Zhi
- Cheng Shan
- Cheng Si-Bo
- Cheng Tong-Guang
- Dai Lian-Rong
- Dai Ling-Yun
- Dai Xin-Chen
- Denig Achim
- Denisenko Igor
- Derkach Denis
- Ding Heng-Tong
- Ding Ming-Hui
- Ding Xiao
- Dong Liao-Yuan
- Du Yong
- Egorov Prokhor
- Fan Kuan-Jun
- Fan Si-Yuan
- Fang Shuang-Shi
- Fang Zhu-Jun
- Feng Song
- Feng Xu
- Fu Hai-Bing
- Gao Jun
- Gao Yuan-Ning
- Gao Zi-Han
- Geng Cong
- Geng Li-Sheng
- Gong Hai-Liang
- Gong Jia-Ding
- Gong Li
- Gong Shao-Kun
- Gonzàlez-Solís Sergi
- Gou Bo-Xing
- Gu Duan
- Guo Hao
- Guo Jun
- Guo Teng-Jun
- Guo Xin-Heng
- Guo Yu-Hui
- Guo Yu-Ping
- Guo Zhi-Hui
- Haciomeroglu Selcuk
- Hamwi Eiad
- Han Cheng-Dong
- Han Ting-Ting
- Hao Xi-Qing
- He Chong-Chao
- He Ji-Bo
- He Tian-Long
- He Xiao-Gang
- Hosaka Masahito
- Hou Kai-Wen
- Hou Zhi-Long
- Hu Dong-Dong
- Hu Hai-Ming
- Hu Hao
- Hu Qi-Peng
- Hu Tong-Ning
- Hu Xiao-Cheng
- Hu Yu
- Hu Zhen
- Huang Da-Zhang
- Huang Fei
- Huang Guang-Shun
- Huang Liang-Sheng
- Huang Peng-Wei
- Huang Rui-Xuan
- Huang Xing-Tao
- Huang Xue-Lei
- Huang Zhi-Cheng
- Ji Wang
- Jia Peng-Kun
- Jia Sen
- Jia Ze-Kun
- Jiang Hong-Ping
- Jiang Hou-Bing
- Jiao Jian-Bin
- Jin Ming-Jie
- Jin Su-Ping
- Jin Yi
- Kang Daekyoung
- Kang Xian-Wei
- Kang Xiao-Lin
- Kaptari Leonid
- Kolcu Onur Bugra
- Koop Ivan
- Kravchenko Evgeniy
- Kudenko Yury
- Küßner Meike
- Leng Yong-Bin
- Levichev Eugene
- Li Chao
- Li Chun-Yuan
- Li Chun-Hua
- Li Hai Tao
- Li Hai-Bo
- Li Hang-Zhou
- Li Heng-Ne
- Li Hong-Lei
- Li Hui-Jing
- Li Hui-Lin
- Li Jia-Rong
- Li Jin
- Li Lei
- Li Min
- Li Pei-Rong
- Li Pei-Lian
- Li Ren-Kai
- Li Sang-Ya
- Li Shu
- Li Teng
- Li Tian-You
- Li Wei-Wei
- Li Wen-Jun
- Li Xin
- Li Xin-Qiang
- Li Xin-Bai
- Li Xuan
- Li Xun-Feng
- Li Yan-Feng
- Li Ya-Xuan
- Li Ying
- Li Yu-Bo
- Liang Jian
- Liang Xiao
- Liang Yu
- Liang Ze-Rui
- Lin Chuang-Xin
- Lin De-Xu
- Lin Ting
- Lin Yu-Gen
- Liu Chao
- Liu Chao
- Liu Chia-Wei
- Liu Gang-Wen
- Liu Hang
- Liu Hong-Bang
- Liu Jian-Bei
- Liu Jian-Dang
- Liu Lang-Tian
- Liu Liang-Chen
- Liu Ming-Yi
- Liu Shu-Bin
- Liu Tao
- Liu Tian-Bo
- Liu Xiang
- Liu Xiao-Yu
- Liu Xin
- Liu Xu-Yang
- Liu Yan-Rui
- Liu Yan-Lin
- Liu Yan-Wen
- Liu Yi
- Liu Yuan
- Liu Zhan-Wei
- Liu Zhao-Feng
- Liu Zhi-Qing
- Liu Zi-Rui
- Liu Zuo-Wei
- Lu Cai-Dian
- Lu Miao-Ran
- Lu Peng-Cheng
- Lu Yu
- Luo Qing
- Luo Tao
- Luo Tao
- Luo Xiao-Feng
- Lv Hui-Hui
- Lyu Shuo-Tian
- Lyu Xiao-Rui
- Ma Bo-Qiang
- Ma Cheng-Long
- Ma Shao-Hang
- Ma Teng
- Ma Wen-Bin
- Meng Yu
- Fan Meng-Xu
- Miao Xue-Ce
- Migliorati Mauro
- Milardi Catia
- Mineeva Taisiya
- Mo Yi-Hao
- Mullor Hector Gisbert
- Musa Elaf
- Nakamura Satoshi
- Nefediev Alexey
- Nie Yuan-Cun
- Ohmi Kazuhito
- Padmanath M.
- Pakhlov Pavel
- Pang Jian
- Passemar Emilie
- Pei Guo-Xi
- Pei Hua
- Peng Hai-Ping
- Peng Liang
- Ping Rong-Gang
- Pire Bernard
- Prasad Vindhyawasini
- Qi Bin-Bin
- Qi Zhi-Jun
- Qian Yi
- Qiao Cong-Feng
- Qin Jia-Jia
- Qin Long-Yu
- Qin Qin
- Qin Xiao-Shuai
- Ratnikov Fedor
- Roberts Craig
- Rodríguez-Sánchez Antonio
- Rogovsky Yury
- Rogozhin Platon
- Roig Pablo
- Ruan Man-Qi
- Segovia Jorge
- Shang Feng-Lei
- Shang Lei
- Shangguan Jian-Feng
- Shao Ding-Yu
- Shao Ming
- Shao Zhuo-Xia
- Shen Cheng-Ping
- Shen Hong-Fei
- Shen Xiao-Min
- Shen Zhong-Tao
- Shi Cai-Tu
- Shi Jia-Lei
- Shi Rui-Xiang
- Shi Yu-Kun
- Si Zong-Guo
- Silva Luiz Vale
- Skamarokha Mikhail
- Su Jun-Chao
- Sun Guang-Bao
- Sun Jun-Feng
- Sun Kun
- Sun Li
- Sun Ming-Kai
- Sun Rui
- Sun Xu-Lei
- Tang Jing-Yu
- Tang Yin-Gao
- Tang Ze-Bo
- Tao Wei
- Telnov Valery
- Teng Jia-Xiu
- Tikhonov Yuriy
- Tsai Cheng-Ying
- Uglov Timofey
- Vagnoni Vincenzo
- Valencia German
- Wan Guan-Yue
- Wang An-Xin
- Wang Bin
- Wang Cheng-Zhe
- Wang En
- Wang Hong-Jin
- Wang Jia
- Wang Jie
- Wang Jun-Zhang
- Wang Lei
- Wang Lei
- Wang Lin
- Wang Qian
- Wang Qian
- Wang Sheng-Quan
- Wang Sheng-Yuan
- Wang Shi-Kang
- Wang Wei
- Wang Wei-Ping
- Wang Xiang-Peng
- Wang Xia-Yu
- Wang Xiong-Fei
- Wang Ya-Qian
- Wang Yu-Ming
- Wang Yu-Hao
- Wang Zeren Simon
- Wang Zhi
- Wang Zhi-Gang
- Wang Zhi-Yong
- Wang Zi-Yu
- Wang Zi-Rui
- Wei Bing-Feng
- Wei Shao-Qing
- Wei Shu-Yi
- Wei Xiao-Min
- Wei Ya-Jing
- Wei Ye-Long
- Wiedner Ulrich
- Wu Jia-Jun
- Wu Jun
- Wu Qun
- Wu Sang
- Wu Xin
- Wu Xing-Gang
- Wu Xuan
- Wu Yong-Cheng
- Wu Yu-Sheng
- Xia Lei
- Xiao Zhi-Gang
- Xie Chun-Jie
- Xie Kai-Bo
- Xiong Zi-Yu
- Xu Ji
- Xu Lai-Lin
- Xu Shu-Sheng
- Xu Xin
- Xu Yue
- Yan Liang
- Yan Wen-Biao
- Yan Xue-Qing
- Yang Chi
- Yang Hai-Jun
- Yang Hong-Tao
- Yang Jun
- Yang Peng-Hui
- Yang Shuai
- Yang Tao
- Yang Wei-Hua
- Yang Xing-Hua
- Yang Xue-Ting
- Yang Yue-Ling
- Yang Zhen-Wei
- Yang Zhong-Juan
- Yao De-Liang
- Ye Zao-Chen
- Yi Kai
- Yi Li
- Yin Li-Xin
- You Zheng-Yun
- Yu Chen
- Yu Ze
- Yuan Jing
- Yuan You-Jin
- Yury Nefedov
- Zeng Yi-Feng
- Zha Wang-Mei
- Zhang Ai-Lin
- Zhang Ding-Yue
- Zhang Guang-Yi
- Zhang Guo-Heng
- Zhang Hai-Yan
- Zhang Hao-Ran
- Zhang Hong-Hao
- Zhang Hui-Bin
- Zhang Jia-Lian
- Zhang Jian-Rong
- Zhang Jian-Hui
- Zhang Jian-Yu
- Zhang Jie-Lei
- Zhang Lei
- Zhang Liang
- Zhang Ling-Hua
- Zhang Lin-Hao
- Zhang Ning
- Zhang Qiu-Yan
- Zhang Quan-Zheng
- Zhang Rui
- Zhang Rui-Yang
- Zhang Shao-Ru
- Zhang Sheng-Hui
- Zhang Shu-Lei
- Zhang Wen-Chao
- Zhang Xiao-Yang
- Zhang Xiao-Ming
- Zhang Xiao-Tao
- Zhang Xin
- Zhang Xin-Hui
- Zhang Yan-Xi
- Zhang Ya-Teng
- Zhang Yi-Hao
- Zhang Yi-Fei
- Zhang Yu
- Zhang Yu
- Zhang Yu-Mei
- Zhang Zhen-Yu
- Zhang Zhi-Qing
- Zhang Zhi-Cai
- Zhao Jia-Yao
- Zhao Ming-Gang
- Zhao Qiang
- Zhao Rui-Guang
- Zhao Yang-Cheng
- Zhao Ze-Xuan
- Zhao Zheng-Guo
- Zhemchugov Alexey
- Zheng Bo
- Zheng Jing-Xin
- Zheng Liang
- Zheng Ran
- Zheng Xu-Chang
- Zheng Yang-Heng
- Zhong Bin
- Zhou Dai-Cui
- Zhou De-Min
- Zhou Hang
- Zhou Hao
- Zhou Jian
- Zhou Jian-Xin
- Zhou Qin-Song
- Zhou Shi-Yu
- Zhou Xiang
- Zhou Xiao-Kang
- Zhou Xiao-Rong
- Zhou Ya-Jin
- Zhou Yi
- Zhou Yi-Mei
- Zhou Ze-Ran
- Zhu Bing
- Zhu Jing-Yu
- Zhu Jing-Ya
- Zhu Lin
- Zhu Rui-Lin
- Zhu Xing-Hao
- Zhu Ying-Chun
- Zhu Zian
- Zobov Mikhail
- Zong Yang
- Zou Bing-Song
- Zou Ye
- Zu Jian
Nuclear science and techniques / Chinese Nuclear Society, Elsevier, 2025, 36 (12), pp.242. Abstract Electron–positron colliders operating in the GeV center-of-mass range, or tau-charm energy region, have been proved to enable competitive frontier research due to several unique features. With the progress of high-energy physics in the last two decades, a new-generation Tau-Charm factory, called the Super Tau-Charm Facility (STCF), has been actively promoted by the particle physics community in China. STCF has the potential to address fundamental questions such as the essence of color confinement and the matter–antimatter asymmetry within the next decades. The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5 × 10 34 cm −2 s −1 that is optimized at a center-of-mass energy of 4 GeV, which is approximately 50 times that of the currently operating Tau-Charm factory—BEPCII. The STCF accelerator has two main parts: a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams. As a typical third-generation electron–positron circular collider, the STCF accelerator faces many challenges in both accelerator physics and technology. In this paper, the conceptual design of the STCF accelerator complex is presented, including the ongoing efforts and plans for technological research and development, as well as the required infrastructure. The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan (2026–2030). (10.1007/s41365-025-01833-x)
DOI : 10.1007/s41365-025-01833-x
Supersymmetry Breaking with Fields, Strings and Branes
- Dudas Emilian
- Mourad J.
- Sagnotti A.
, 2025. review article, 377 pages, LaTeX, 38 eps figures, to appear in Physics Reports
2025 EIC-France Workshop: Physics Highlights and Perspectives
- Arleo F
- Bertone V
- Bettane J
- Blossier B
- Bock F
- Bossù F
- Boussarie R
- Bouyjou F
- Brand-Foissac O
- Bucuru Rodriguez N.L
- Calvelli V
- Caucal P
- Chatagnon P
- Daskalas D
- de la Taille C
- Deconinck W
- Delbart A
- Didelez J
- Dulucq F
- Ziehlmann P. Dumas
- Dupre R
- Berni M. El
- Extier S
- Fazio S
- Francisco A
- Fucilla M
- Gardner S
- Guenego B
- Guillossou-Jnaid K
- Hoballah M
- d'Hose N
- Huang H
- Iancu E
- Jalilian-Marian J
- Jeanneau F
- Rajan A. John Rubesh
- Kachkachi N.E
- Kuan C.-T
- Lajoie J
- Lansberg J.P
- Serin L
- Le Dortz O
- Le Roux Y
- Lynch K
- Marchand D
- Marquet C
- Mehrez F
- Mezrag C
- Migayron A
- Montaña G
- Moutarde H
- Muñoz Camacho C
- Nabeebaccus S
- Neyret D
- Nguyen M
- Niccolai S
- Obraztsov S
- Panebianco S.M
- Perez D
- Pire B
- Ronayette M
- Royer L
- Sazdjian H
- Schienbein I
- Sharma A
- Shatat A
- Shi Y
- Soulier A
- Szymanowski L
- Thienpont D
- Torrento A
- van Hulse C
- Verplancke A
- Vetter S
- Voutier E
- Yarwick J
- Wanlin E
- Wallon S
- Zaidan Z
, 2025. This document presents a synthesis of the theory contributions and discussions from the 2nd EIC-France Workshop, held at IJCLab (Orsay) on 1-3 December 2025. The workshop brought together members of the French hadron-physics community to review recent theoretical developments relevant to the future Electron-Ion Collider (EIC) and to coordinate national efforts in preparation for its early physics program. The report first summarizes the collider's initial running conditions and luminosity performance, as outlined in the EIC Early Science Matrix. It then provides concise overviews of the theoretical presentations on inclusive, semi-inclusive, exclusive, heavy-flavor, and small-x physics. Based on these discussions, two measurements emerged as especially well suited for early EIC operation and strongly aligned with areas of established French expertise: inclusive diffraction and inclusive quarkonium production. These channels offer clean signatures, robust theoretical interpretability, and direct sensitivity to fundamental QCD phenomena such as gluon saturation, heavy-quark dynamics, and the small-x structure of hadrons and nuclei. In addition, the workshop identified longer-term physics opportunities that will benefit from the full capabilities of the EIC after its ramp-up phase. These include accessing the three-dimensional structure of the pion through the Sullivan process and a broader program of exclusive three-body final states, both of which represent high-impact avenues for exploring hadronic structure and non-perturbative QCD. Together, the elements summarized in this report provide a coherent overview of the strategic priorities and scientific ambitions shaping the French community's contribution to the EIC physics program.
Fermion parity switches imprinted in the photonic field of cavity embedded Kitaev chains
- Becerra Victor Fernandez
- Dmytruk Olesia
, 2025. The entanglement of electronic states with quantum light in cavity embedded systems has opened new avenues to manipulate quantum materials. In this work we investigate the Kitaev chain coupled to a single mode photonic cavity. Using exact diagonalization we calculate the many-body energy spectrum of the electron-photon Hamiltonian in finite-length chains. We find two distinct types of ground states, one with a well defined parity and another with an alternating parity where a doubly degenerate ground state takes place at exceptional points, known as parity switching points. The double ground state hosts edge states weakly affected by the cavity coupling, even in the low frequency regime, in contrast with higher excited states showing strong dependence with the cavity coupling. Besides the electronic quantities, we also find that the photon number peaks at values of the chemical potential corresponding to parity switching points. Therefore, we suggest that quantum optics experiments could be employed to detect the double ground state hosting edge states weakly hybridized with light. Finally, calculations of photonic quadratures reveal squeezed states that are both captured by the exact diagonalization technique and mean field decoupling. However, within these two approaches differences in the photon probability in odd numbers of photons are reported.
Superconductivity of Bad Fermions: Origin of Two Gaps in HTSC Cuprates
- Stepanov E.
- Iskakov S.
- Katsnelson M.
- Lichtenstein A.
, 2025. We investigate the spectral properties of the doped ${t-t'}$ Hubbard model with parameters typical for high-temperature cuprate superconductors. Our approach is based on a novel strong-coupling Green's function expansion around a reference system -- the exactly solvable undoped particle-hole symmetric Hubbard lattice -- that possesses a large antiferromagnetic Mott-Hubbard-Slater gap in the electron spectrum. The electron spectral function in the case of a large next-nearest-neighbor hopping ${t'=-0.3t}$, which is characteristic of the ${T_c \approx 100\,\text{K}}$ family of cuprates, reveals a strongly renormalized flat band feature with a pseudogap around the antinodal point. The superconducting response of this system to a small ${d_{x^2-y^2}}$-like external field exhibits a very unusual form. It features a pseudogap at the antinodal point in the normal part of the Nambu Green's function, related to a ``bad-fermion'' behavior in a normal phase, as well as a ${d}$-wave-like structure in the anomalous (Gorkov's) Green's function, with zero response at the nodal point of the Brillouin zone. Remarkably, we find that the anomalous part of the response deviates essentially from the simplest ${(\cos{k_x}-\cos{k_y})}$ form in momentum space. Specifically, its extrema are shifted away from the ${(π,0)}$ and ${(0,π)}$ points due to suppression of the response by the pseudogap. The observed two-gap structure of the electron spectra in a generic strong-coupling model of cuprates can serve as a basis for phenomenological treatment of different physical properties of high-temperature superconductors within two-fluid model. (10.48550/arXiv.2502.08635)
DOI : 10.48550/arXiv.2502.08635
Cluster-diagrammatic D-TRILEX approach to non-local electronic correlations
- Fossati Félix
- Stepanov Evgeny A
, 2025. In this work, we extend the theoretical approach known as "D-TRILEX", developed for solving correlated electronic systems, to a cluster reference system for the diagrammatic expansion. This framework allows us to consistently combine the exact treatment of short-range correlation effects within the cluster, with an efficient diagrammatic description of the long-range charge and spin collective fluctuations beyond the cluster. We demonstrate the effectiveness of our approach by applying it to the one-dimensional nano-ring Hubbard model, where the low dimensionality enhances non-local correlations. Our results show that the cluster extension of D-TRILEX accurately reproduces the electronic self-energy at momenta corresponding to the Fermi energy, in good agreement with the numerically exact quantum Monte Carlo solution of the problem, and outperforms significantly more computationally demanding approach based on the parquet approximation. We show that the D-TRILEX diagrammatic extension drastically reduces the periodization ambiguity of cluster quantities when mapping back to the original lattice, compared to cluster dynamical mean-field theory (CDMFT). Furthermore, we identify the CDMFT impurity problem as the main source of the translational-symmetry breaking and propose the computational scheme for improving the starting point for the cluster-diagrammatic expansion.
Non-Local Correlation Effects in DC and Optical Conductivity of the Hubbard Model
- Dasari Nagamalleswararao
- Strand Hugo U R
- Eckstein Martin
- Lichtenstein Alexander I
- Stepanov Evgeny A
, 2025. Conductivity is one of the most direct probes of electronic systems, yet its theoretical description remains challenging in the presence of strong non-local correlations. In this Letter, we analyze the conductivity of the half-filled single-band Hubbard model and identify the role of spatial correlations across the Mott transition. We show that in the correlated metallic regime, an accurate description of the conductivity requires not only the correct spectral function but also the inclusion of complex multi-electron processes encoded in vertex corrections. The crossover to the Mott insulating regime is marked by a vanishing contribution of vertex corrections to the DC conductivity. However, in the Mott insulating case, vertex corrections remain significant for the optical conductivity.
Triviality vs perturbation theory: an analysis for mean-field $φ^4$-theory in four dimensions
- Kopper Christoph
- Wang Pierre
, 2025. We have constructed the mean-field trivial solution of the $φ^4$ theory $O(N)$ model in four dimensions in two previous papers using the flow equations of the renormalization group. Here we establish a relation between the trivial solutions we constructed and perturbation theory. We show that if an UV-cutoff is maintained, we can define a renormalized coupling constant $g$ and obtain the perturbative solutions of the mean-field flow equations at each order in perturbation theory. We prove the local Borel-summability of the renormalized mean-field perturbation theory in the presence of an UV cutoff and show that it is asymptotic to the non-perturbative solution.
Supersymmetry Breaking with Fields, Strings and Branes
- Dudas E
- Mourad J
- Sagnotti A
, 2025. The first part of this review tries to provide a self-contained view of supersymmetry breaking from the bottom-up perspective. We thus describe N=1 supersymmetry in four dimensions, the Standard Model and the MSSM, with emphasis on the ``soft terms'' that can link it to supergravity. The second part deals with the top-down perspective. It addresses, insofar as possible in a self-contained way, the basic setup provided by ten-dimensional strings and their links with supergravity, toroidal orbifolds, Scherk-Schwarz deformations and Calabi-Yau reductions, before focusing on a line of developments that is closely linked to our own research. Its key input is drawn from ten-dimensional non-tachyonic string models where supersymmetry is absent or non-linearly realized, and runaway ``tadpole potentials'' deform the ten-dimensional Minkowski vacua. We illustrate the perturbative stability of the resulting most symmetrical setups, which are the counterparts of circle reduction but involve internal intervals. We then turn to a discussion of fluxes in Calabi-Yau vacua and the KKLT setup, and conclude with some aspects of Cosmology, emphasizing some intriguing clues that the tadpole potentials can provide for the onset of inflation. The appendices collect some useful material on global and local N=1 supersymmetry, in components and in superspace, on string vacuum amplitudes, and on convenient tools used to examine the fluctuations of non-supersymmetric string vacua.
Topological Insulators and Local Properties of Orbital Magnetization
- Al Saati Sariah
, 2025. This thesis presents an analytical theoretical work conducted in the field of topological materials within condensed matter physics. We focus in this thesis on the local properties of topological insulators and explore in detail the effects of the bulk-boundary correspondence in these materials.We first investigate the Hall transport properties of a two-dimensional topological metal model that exhibits a Fermi surface in the form of a closed contour, known as a nodal ring. Our aim is to characterize the nature of the topological invariant associated with this metal, and to evaluate the effects of this invariant on the Hall transport properties of the model.Next, more generally, we consider systems described within the tight-binding formalism, and we develop a new analytical theory for computing the orbital magnetization resolved at the level of a single lattice site. Orbital magnetization is a magnetic property of materials known to exhibit topological features, similar to Hall conductance, due to the relationship between these two observables expressed by the Středa formula.This theory is valid for two- and three-dimensional materials, as well as for amorphous systems, finite-sized systems, and periodic crystals with an arbitrary number of bands. It reveals, for the first time, the orbital magnetic texture of quantum materials at the sublattice scale, and in particular allows us to identify orbital ferromagnetic and antiferromagnetic phases in non-topological insulators.Applying this theory to topological insulators provides a novel perspective on fundamental aspects of the bulk-boundary correspondence—a key property of topological materials that is often discussed in the literature but whose detailed mechanisms have remained elusive until now. (10.70675/3740e9d6z6be2z4b5bz8f5ez53973172284c)
DOI : 10.70675/3740e9d6z6be2z4b5bz8f5ez53973172284c
Nature of momentum- and orbital-dependent magnetic fluctuations in Sr2RuO4
- Chatzieleftheriou Maria
- Rudenko Alexander N
- Sidis Yvan
- Biermann Silke
- Stepanov Evgeny A
Physical Review B, American Physical Society, 2025, 112 (19), pp.195118. (10.1103/ts6y-zb6m)
DOI : 10.1103/ts6y-zb6m
Unified Resummation of Soft Gluon Radiation in Heavy Meson Pair Photoproduction
- Marquet Cyrille
- Shi Yu
- Xiao Bo-Wen
, 2025. We develop a unified resummation framework for heavy-meson pair photoproduction that treats soft-gluon radiation in a massive scheme for $|\boldsymbol q| \lesssim m_Q$ and is consistent with the massless limit $m_Q \ll |\boldsymbol q|$, where $\boldsymbol q$ denotes the transverse momentum of the pair and $m_Q$ the quark mass. This framework describes the full correlation regime $|\boldsymbol q| \ll |\boldsymbol P|$, with $\boldsymbol P$ the pair's relative transverse momentum. Next, within the Color Glass Condensate framework, we quantify the impact of soft gluon radiation on two important phenomenological observables, namely, the azimuthal $Δϕ$ correlation and the harmonic asymmetries $\langle \cos(2nϕ_{qP})\rangle$. Our results show that the resummation provides an excellent description of the H1 $Δϕ$ data. We then find that the angular-asymmetry harmonics are sizable and their ratios in $γA$ to $γp$ collisions are highly sensitive to gluon saturation. We further find a clear mass hierarchy in both observables, indicating that heavy-quark masses suppress soft radiation and thereby enhance genuine small-$x$ saturation signals. Our work demonstrates that heavy-quark pair photoproduction provides a quantitative probe of gluon saturation, directly measurable in forthcoming EIC and UPC measurements. Finally, the unified resummation is readily extendable to other processes involving massive particles and jets in both $eA$ and $pA$ collisions.
Design principles of deep translationally symmetric neural quantum states for frustrated magnets
- Nutakki Rajah
- Shokry Ahmedeo
- Vicentini Filippo
Physical Review Research, American Physical Society, 2025, 7 (4), pp.043099. Deep neural-network quantum states have emerged as a leading method for studying the ground states of quantum magnets. Successful architectures exploit translational symmetry, but the root of their effectiveness and differences between architectures remain unclear. Here, we apply the ConvNext architecture, designed to incorporate elements of transformers into convolutional networks, to quantum many-body ground states. We find that it is remarkably similar to the factored vision transformer, which has been employed successfully for several frustrated spin systems, allowing us to relate this architecture to more conventional convolutional networks. Through a series of numerical experiments, we design the ConvNext to achieve greatest performance at lowest computational cost, and then apply this network to the Shastry-Sutherland and J 1 − J 2 models, obtaining variational energies comparable to the state of the art, providing a blueprint for network design choices of translationally symmetric architectures to tackle challenging ground-state problems in frustrated magnetism. (10.1103/ybgv-35jm)
DOI : 10.1103/ybgv-35jm
Coupling quantum spin ice to matter on the centered pyrochlore lattice
- Nutakki Rajah
- Capponi Sylvain
- Jaubert Ludovic D. C.
- Pollet Lode
Physical Review B, American Physical Society, 2025, 112 (14), pp.144437. The low-energy physics of quantum spin ice is known to support an emergent form of quantum electrodynamics (QED), where magnetic monopoles exist and the fine-structure constant is material dependent. In this article, we show how this QED is modified via a coupling to dynamical matter on the centered pyrochlore lattice, a structure that has recently been synthesized using metal-organic frameworks. Specifically, we study the low-energy properties of the S = 1 / 2 quantum XXZ model on the centered pyrochlore lattice, with a focus on the sign-problem-free region. At fourth order in degenerate perturbation theory, this model hosts a quantum spin liquid distinct from the well-known U(1) quantum spin ice on the pyrochlore because of the presence of dynamical matter in the ground state. Exact diagonalization results are consistent with this quantum spin liquid over an extended region of the ground-state phase diagram, although potential quantum critical points within this region could indicate a richer phase structure. Our work thus expands the physics of quantum spin ice in an experimentally motivated geometry, showing how the emergent QED can be coupled to dynamical matter at zero temperature. (10.1103/xrmm-vr6m)
DOI : 10.1103/xrmm-vr6m
A comparative study of thermal transport properties in FeS2 and RuS2
- Agnarelli L
- Pelloquin D
- Daou R
- Maignan A
- Hébert S
- Mukherjee A
- Subedi A
Journal of Physics: Condensed Matter, IOP Publishing [1989-....], 2025, 37 (41), pp.415701. Abstract The thermal properties of RuS 2 have been investigated and compared to those of FeS 2 , its well-documented 3d analogue. Particular care was required in the synthesis of RuS 2 by solid-state reaction, due to the strongly exothermic nature of the reaction, in contrast to the easier preparation of FeS 2 . Dense polycrystalline samples were obtained and characterized by x-ray diffraction, electron microscopy, and transport measurements. While FeS 2 exhibits very high thermal conductivity, reaching ∼175 Wm −1 K −1 at 75 K, RuS 2 shows much lower values, with κ ∼ 20 Wm −1 K −1 at 300 K. First-principles calculations reveal that the intrinsic lattice conductivities of FeS 2 and RuS 2 are comparable, with a modest reduction in RuS 2 arising from enhanced phonon–phonon Umklapp scattering. The much stronger experimental suppression is explained by extrinsic microstructural disorder, consistent with scanning electron microscope and x-ray powder diffraction evidence of smaller grains and reduced crystallinity. These results highlight both the synthetic challenges, the moderate role of Umklapp scattering, and the decisive role of microstructure in shaping the transport properties of 4d transition-metal pyrites. (10.1088/1361-648X/ae0b21)
DOI : 10.1088/1361-648X/ae0b21
From the Rose–DuBois ansatz of hotspot fields to the instanton solution: A pedestrian presentation
- Mounaix Philippe
Physics of Plasmas, American Institute of Physics, 2025, 32 (10). This paper gives a pedestrian presentation of some technical results recently published in mathematical physics with non-trivial implications for laser–plasma interaction. The aim is to get across the main results without going into the details of the calculations or offering a specialist's user guide but by focusing conceptually on how these results modify the commonly held description—in terms of laser hotspot fields—of backscattering instabilities with a spatially smoothed laser beam. The intended readers are plasma physicists as well as graduate students interested in laser–plasma interaction. No prior knowledge of scattering instabilities is required. Step by step, we explain how the laser hot spots are gradually replaced with other structures, called instantons, as the amplification of the scattered light increases. In the amplification range of interest for laser–plasma interaction, instanton–hotspot complexes tend to appear in the laser field (in addition to the expected hot spots), with a non-negligible probability. For even larger amplifications and systems longer than a hotspot length, the hotspot field description is clearly invalidated by the instanton takeover. (10.1063/5.0282684)
DOI : 10.1063/5.0282684

Retour aux années