Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment a_{τ}. The dataset corresponds to an integrated luminosity of 1.44  nb^{-1} of LHC Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a τ-lepton decay, an electron or charged-particle track(s) from the other τ-lepton decay, little additional central-detector activity, and no forward neutrons. The γγ→ττ process is observed in Pb+Pb collisions with a significance exceeding 5 standard deviations and a signal strength of μ_{ττ}=1.03_{-0.05}^{+0.06} assuming the standard model value for a_{τ}. To measure a_{τ}, a template fit to the muon transverse-momentum distribution from τ-lepton candidates is performed, using a dimuon (γγ→μμ) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a_{τ} is -0.057

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.131.151802DOI Listing

Publication Analysis

Top Keywords

pb+pb collisions
12
γγ→ττ process
8
constraints τ-lepton
8
τ-lepton anomalous
8
anomalous magnetic
8
magnetic moment
8
τ-lepton decay
8
τ-lepton
5
observation γγ→ττ
4
process pb+pb
4

Similar Publications

Asthenospheric flow and lithospheric erosion driving the outward growth of the northeastern Tibetan Plateau.

Sci Bull (Beijing)

August 2025

Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.

The northeastern (NE) Tibetan Plateau is extruding eastward at a rapid rate (∼15 mm a), but the role of the upper mantle in this process remains unclear. Early-Miocene primary melilitites from the leading edge of the extruding plateau provide critical insights into the upper mantle dynamics. Geochemical and Sr-Nd-Pb-Os isotopic data, supported by experimental melt comparisons, reveal that these melilitites originate from a hybrid source of CO-bearing mantle source, probably dominated by peridotite and pyroxenite/wehrlite lithologies.

View Article and Find Full Text PDF

Evidence of slab tearing on an inherited Mesozoic rift transfer fault in the Betic Cordillera.

Sci Rep

August 2025

Instituto Geológico y Minero de España. Consejo Superior de Investigaciones Científicas (IGME-CSIC), Madrid, Spain.

The Western Mediterranean has undergone complex subduction and collision between the African and Iberian plates, influenced by slab segmentation and melt generation. Despite numerous studies aimed at understanding these connections, the style of subduction remains controversial. Utilizing a compilation of geophysical data and a new map of magmatic suites along the Western Betic Cordillera, along with geochemical and geochronological analyses, this paper presents a 3D reconstruction of a segmented subducting slab beneath the Gibraltar Arc, with a focus on the nature and timing of slab tearing and magmatism.

View Article and Find Full Text PDF

The ALICE Collaboration reports measurements of the large relative transverse momentum (k_{T}) component of jet substructure in pp and Pb-Pb collisions at center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV. Enhancement in the yield of such large-k_{T} emissions in head-on Pb-Pb collisions is predicted to arise from partonic scattering with quasiparticles of the quark-gluon plasma.

View Article and Find Full Text PDF

We present the first theoretical study of the polarization of lepton pairs produced in sqrt[s_{NN}]=5.02  TeV Pb+Pb collisions at the LHC, using next-to-leading order (NLO) dilepton emission rates. These calculations employ a multistage framework to simulate the evolution of relativistic heavy-ion collisions, and to explore the sensitivity of polarization to early times.

View Article and Find Full Text PDF

Regimes and Breakup Model of Head-On Collisions of Unequal-Sized Water Nanodroplets.

Langmuir

July 2025

School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, P. R. China.

The difference in diameters of unequal-sized water nanodroplets can significantly alter the collision regimes, and a quantitative model for predicting nanodroplet breakup remains unclear. This study employs molecular dynamics simulations to investigate the head-on collisions of unequal-sized nanodroplets. The interactions during head-on collisions are analyzed over a broad spectrum of Weber numbers and size ratios, allowing for a comprehensive characterization of the collision regime diagram.

View Article and Find Full Text PDF