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TH Articles

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Axion Star Explosions and the Reionization History of the Universe / Escudero, Miguel (CERN)
Cosmological structure formation simulations of ultralight axion-like dark matter have shown that an axion star forms at the center of every dark matter halo in the Universe. These axion stars would then form in large numbers during the dark ages, $z \lesssim 70$. [...]
arXiv:2402.06547; CERN-TH-2024-023.- 2024-03-01 - 11 p. - Published in : PoS COSMICWISPers (2024) 012 Fulltext: document - PDF; 2402.06547 - PDF;

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Mixed NNLO QCD × electroweak corrections to single-Z production in pole approximation: differential distributions and forward-backward asymmetry / Dittmaier, Stefan (Freiburg U.) ; Huss, Alexander (CERN) ; Schwarz, Jan (Freiburg U.)
Radiative corrections in pole approximation, which are based on the leading contribution in a systematic expansion of amplitudes about resonance poles, naturally decompose into factorizable corrections attributed to the production or decay of the resonance and non-factorizable corrections induced by soft photon (or gluon) exchange between those subprocesses. In this paper we complete an earlier calculation of mixed QCD$\times$electroweak corrections of $\mathcal{O}(\alpha_s\alpha)$ to the neutral-current Drell-Yan cross section in pole approximation by including the previously neglected corrections that are solely related to the Z-boson production process. [...]
arXiv:2401.15682; FR-PHENO-2024-01; CERN-TH-2024-001.- 2024-05-14 - 42 p. - Published in : JHEP 2405 (2024) 170 Fulltext: document - PDF; 2401.15682 - PDF;

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Astrophysical Axion Bounds: The 2024 Edition / Caputo, Andrea ; Raffelt, Georg
We review the current status of astrophysical bounds on QCD axions, primarily based on the observational effects of nonstandard energy losses on stars, including black-hole superradiance. Over the past few years, many of the traditional arguments have been reexamined both theoretically and using modern data and new ideas have been put forth. [...]
arXiv:2401.13728; MPP-2024-13; CERN-TH-2024-013.- 2024-03-11 - 81 p. - Published in : 10.22323/1.454.0041 Fulltext: document - PDF; 2401.13728 - PDF;

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Geometry of the spectral parameter and renormalisation of integrable sigma-models / Lacroix, Sylvain (ETH, Zurich (main)) ; Wallberg, Anders (CERN ; Ecole Polytechnique, Lausanne ; Zurich, ETH)
In the past few years, the unifying frameworks of 4-dimensional Chern-Simons theory and affine Gaudin models have allowed for the systematic construction of a large family of integrable $\sigma$-models. These models depend on the data of a Riemann surface $C$ (here of genus 0 or 1) and of a meromorphic 1-form $\omega$ on $C$, which encodes the geometry of their spectral parameter and the analytic structure of their Lax connection. [...]
arXiv:2401.13741; CERN-TH-2024-008.- 2024-05-09 - 62 p. - Published in : JHEP 2405 (2024) 108 Fulltext: document - PDF; 2401.13741 - PDF;

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Hadronic vacuum polarization in the muon $g-2$: The short-distance contribution from lattice QCD / Kuberski, Simon (CERN) ; Cè, Marco (INFN, Milan Bicocca) ; von Hippel, Georg (U. Mainz, PRISMA) ; Meyer, Harvey B. (U. Mainz, PRISMA ; Mainz U., Inst. Phys. ; Darmstadt, GSI) ; Ottnad, Konstantin (U. Mainz, PRISMA) ; Risch, Andreas (Wuppertal U. ; NIC, Zeuthen ; DESY, Zeuthen) ; Wittig, Hartmut (U. Mainz, PRISMA ; Mainz U., Inst. Phys. ; Darmstadt, GSI)
We present results for the short-distance window observable of the hadronic vacuum polarization contribution to the muon $g-2$, computed via the time-momentum representation (TMR) in lattice QCD. A key novelty of our calculation is the reduction of discretization effects by a suitable subtraction applied to the TMR kernel function, which cancels the leading $x_0^4$-behaviour at short distances. [...]
arXiv:2401.11895; MITP-24-011; CERN-TH-2024-011.- 2024-03-29 - 36 p. - Published in : JHEP 2403 (2024) 172 Fulltext: 2401.11895 - PDF; document - PDF;

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Double-graviton production from Standard Model plasma / Ghiglieri, J. (SUBATECH, Nantes) ; Laine, M. (Bern U.) ; Schütte-Engel, J. (UC, Berkeley ; Wako, RIKEN) ; Speranza, E. (CERN)
The thermal plasma filling the early universe generated a stochastic gravitational wave background that peaks in the microwave frequency range today. If the graviton production rate is expressed as a series in a fine-structure constant, $\alpha$, and the temperature over the Planck mass, $T^2_{ } / m_{\rm pl}^2$, then the lowest-order contributions come from single ($\sim \alpha T^2_{ }/m_{\rm pl}^2$) and double ($\sim T^4_{ }/m_{\rm pl}^4$) graviton production via $2\to 2$ scatterings. [...]
arXiv:2401.08766; RIKEN-iTHEMS-Report-24; CERN-TH-2023-216.- 2024-04-23 - 16 p. - Published in : JCAP 2404 (2024) 062 Fulltext: document - PDF; 2401.08766 - PDF;

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Isospin-breaking corrections to weak decays: the current status and a new infrared improvement / Di Carlo, Matteo
We provide an overview of the current state of lattice calculations concerning isospin-breaking corrections in weak decays, focusing in particular on leptonic decays of light pseudoscalar mesons. We examine the two currently existing calculations, placing a particular emphasis on the role of electromagnetic finite-volume corrections. [...]
arXiv:2401.07666; CERN-TH-2024-005.- 2024-01-23 - 18 p.
- Published in : PoS: LATTICE2023 (2024) , pp. 120 Fulltext: 2401.07666 - PDF; document - PDF;
In : 40th International Symposium on Lattice Field Theory (Lattice 2023), Fermilab, Batavia, IL, United States, 30 Jul - 5 Aug 2023, pp.120

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Brickwall in Rotating BTZ: A Dip-Ramp-Plateau Story / Das, Suman (HBNI, Mumbai) ; Kundu, Arnab (HBNI, Mumbai ; CERN)
In this article, building on our recent investigations and motivated by the fuzzball-paradigm, we explore normal modes of a probe massless scalar field in the rotating BTZ-geometry in an asymptotically AdS spacetime and correspondingly obtain the Spectral Form Factor (SFF) of the scalar field. In particular, we analyze the SFF obtained from the single-particle partition function. [...]
arXiv:2310.06438; CERN-TH-2023-187.- 2024-02-08 - 33 p. - Published in : JHEP 2402 (2024) 049 Fulltext: 2310.06438 - PDF; document - PDF;

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Charm quark mass using a massive nonperturbative renormalisation scheme / Del Debbio, Luigi (Piemonte Orientale U., Alessandria ; INFN, Turin) ; Erben, Felix (CERN) ; Flynn, Jonathan (Southampton U.) ; Mukherjee, Rajnandini (Southampton U.) ; Tsang, J. Tobias (CERN)
We present a first numerical implementation of a massive nonperturbative renormalisation scheme, RI/mSMOM, in the study of heavy quarks using the domain-wall fermion action. In particular, we calculate renormalisation constants for fermion bilinears at non-vanishing heavy-quark masses and compare the approach to the continuum of the renormalised charm-quark mass with that from a mass-independent scheme..
arXiv:2312.16537; CERN-TH-2023-250.- 2024-05-02 - 8 p. - Published in : PoS LATTICE2023 (2024) 294 Fulltext: document - PDF; 2312.16537 - PDF;
In : 40th International Symposium on Lattice Field Theory (Lattice 2023), Fermilab, Batavia, IL, United States, 30 Jul - 5 Aug 2023, pp.294

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Extrapolating semileptonic form factors using Bayesian-inference fits regulated by unitarity and analyticity / Flynn, Jonathan ; Juettner, Andreas (CERN ; Southampton U.) ; Tsang, Tobias (CERN)
We discuss our recently proposed model-independent framework for fitting hadronic form-factor data, which are often only available at discrete kinematical points, using parameterisations based on unitarity and analyticity. The accompanying dispersive bound on the form factors (unitarity constraint) is used to regulate the ill-posed fitting problem and allow model-independent predictions over the entire physical range. [...]
arXiv:2312.14631; CERN-TH-2023-248.- 2023-12-27 - 7 p. - Published in : PoS LATTICE2023 (2024) 239 Fulltext: 2312.14631 - PDF; document - PDF;
In : 40th International Symposium on Lattice Field Theory (Lattice 2023), Fermilab, Batavia, IL, United States, 30 Jul - 5 Aug 2023, pp.239

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