Shoji Asai
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
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Shoji Asai has a total of 1000 co-authors. Here are the top co-authors by number of shared publications:
- A. A. Minaenko
CERN
287 shared publications - A. C. Martyniuk
University College London
287 shared publications - A. E. Kiryunin
Max-Planck-Institut für Physik (Werner-Heisenberg-Institut)
287 shared publications - A. G. Kharlamov
CERN
287 shared publications - A. G. Myagkov
CERN
287 shared publications - A. Kourkoumeli-Charalampidi
INFN Sezione di Pavia
287 shared publications
Latest Publications
- Open Access
- 6 November 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (5)
Measurements of longitudinal flow decorrelations in p p and Xe + Xe collisions with the ATLAS detector
Measurements of longitudinal flow decorrelations in 13-TeV p p and 5.44-TeV Xe + Xe collisions with the ATLAS detector are presented. The measurements are performed using the two-particle correlation method, combining charged-particle tracks within | η | < 2.5 with either calorimeter energy clusters or towers within 4.0 < | η | < 4.9 . A template-based subtraction procedure is used to remove nonflow effects in both the p p and the Xe + Xe analyses. The dependence of the longitudinal flow decorrelations on the pseudorapidity separation between the particles is characterized via the slope parameter F n for the elliptic ( n = 2 ) and triangular ( n = 3 ) harmonic moments. The results are reported as a function of charged-particle multiplicity for the p p and Xe + Xe collision systems. Comparing the data to a color string-based model of the initial geometry indicates that in p p and peripheral Xe + Xe collisions, subnucleonic structure, and fluctuations in longitudinal energy deposition are needed to describe the data.
- 6 November 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (5)
Open AccessMeasurements of longitudinal flow decorrelations in p p and Xe + Xe collisions with the ATLAS detector
Measurements of longitudinal flow decorrelations in 13-TeV p p and 5.44-TeV Xe + Xe collisions with the ATLAS detector are presented. The measurements are performed using the two-particle correlation method, combining charged-particle tracks within | η | < 2.5 with either calorimeter energy clusters or towers within 4.0 < | η | < 4.9 . A template-based subtraction procedure is used to remove nonflow effects in both the p p and the Xe + Xe analyses. The dependence of the longitudinal flow decorrelations on the pseudorapidity separation between the particles is characterized via the slope parameter F n for the elliptic ( n = 2 ) and triangular ( n = 3 ) harmonic moments. The results are reported as a function of charged-particle multiplicity for the p p and Xe + Xe collision systems. Comparing the data to a color string-based model of the initial geometry indicates that in p p and peripheral Xe + Xe collisions, subnucleonic structure, and fluctuations in longitudinal energy deposition are needed to describe the data.
- Open Access
- 23 October 2026
- Published by Elsevier in Physics Letters B
- Vol. 883
Measurement of isolated photon plus two-jet correlations in Pb+Pb and pp collisions at 5.02 TeV with ATLAS
- 23 October 2026
- Published by Elsevier in Physics Letters B
- Vol. 883
Open AccessMeasurement of isolated photon plus two-jet correlations in Pb+Pb and pp collisions at 5.02 TeV with ATLAS
- Open Access
- 7 September 2026
- Published by Elsevier in Physics Letters B
- Vol. 881
Measurement of coincident photon-initiated processes in ultra-peripheral Pb+Pb collisions with the ATLAS detector
- 7 September 2026
- Published by Elsevier in Physics Letters B
- Vol. 881
Open AccessMeasurement of coincident photon-initiated processes in ultra-peripheral Pb+Pb collisions with the ATLAS detector
- Open Access
- 5 May 2026
- Published by Elsevier in Physics Letters B
- Vol. 878
Search for long-lived particles using displaced vertices of oppositely charged leptons in 140fb−1 of pp collisions at s=13 TeV with the ATLAS detector
- 5 May 2026
- Published by Elsevier in Physics Letters B
- Vol. 878
Open AccessSearch for long-lived particles using displaced vertices of oppositely charged leptons in 140fb−1 of pp collisions at s=13 TeV with the ATLAS detector
- Open Access
- 30 April 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (4)
Electroweak diboson production in association with a high-mass dijet system in semileptonic final states from pp collisions at $\sqrt{s} = 13$ TeV with the ATLAS detectorThis paper reports the observation of electroweak diboson ( WW / WZ / ZZ ) production in association with a high-mass dijet system, in which final states with one boson decaying leptonically and the other boson decaying hadronically are studied. The hadronically decaying W / Z boson is reconstructed as either two small-radius jets or one large-radius jet with jet substructure requirements. The data analyzed correspond to an integrated luminosity of $$140 \ \text {fb}^{-1}$$ of proton–proton collisions at a center-of-mass energy of $$\sqrt{s}=13$$ TeV collected with the ATLAS detector during the 2015-2018 data taking at the Large Hadron Collider. The electroweak production of WW / WZ / ZZ in association with two jets is observed in a phase space dominated by vector-boson scattering with a significance of $$7.4\sigma $$ (expected $$6.1\sigma $$ ) and the signal strength is determined to be $$1.28^{+0.23}_{-0.21}$$ . The corresponding production cross section in a fiducial phase space is measured in addition. The signal strengths of both electroweak and QCD associated diboson productions are furthermore measured in a two-dimensional fit, the result of which agrees with the Standard Model prediction. The data are interpreted in the context of a dimension-8 effective field theory to probe anomalous quartic gauge couplings resulting in the first set of exclusion limits on the Wilson coefficients in the semileptonic channel reported by the ATLAS Collaboration. The observed limits for the S02, T0 and M0 operators are $$(-\,3.96< f_{S02} / \Lambda ^4 < 3.96)$$ TeV $$^{-4}$$ , $$(-\,0.25< f_{T0} / \Lambda ^4 < 0.22)$$ TeV $$^{-4}$$ , $$(-\,1.26< f_{M0} / \Lambda ^4 < 1.25)$$ TeV $$^{-4}$$ .- 30 April 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (4)
Open AccessElectroweak diboson production in association with a high-mass dijet system in semileptonic final states from pp collisions at $\sqrt{s} = 13$ TeV with the ATLAS detectorThis paper reports the observation of electroweak diboson ( WW / WZ / ZZ ) production in association with a high-mass dijet system, in which final states with one boson decaying leptonically and the other boson decaying hadronically are studied. The hadronically decaying W / Z boson is reconstructed as either two small-radius jets or one large-radius jet with jet substructure requirements. The data analyzed correspond to an integrated luminosity of $$140 \ \text {fb}^{-1}$$ of proton–proton collisions at a center-of-mass energy of $$\sqrt{s}=13$$ TeV collected with the ATLAS detector during the 2015-2018 data taking at the Large Hadron Collider. The electroweak production of WW / WZ / ZZ in association with two jets is observed in a phase space dominated by vector-boson scattering with a significance of $$7.4\sigma $$ (expected $$6.1\sigma $$ ) and the signal strength is determined to be $$1.28^{+0.23}_{-0.21}$$ . The corresponding production cross section in a fiducial phase space is measured in addition. The signal strengths of both electroweak and QCD associated diboson productions are furthermore measured in a two-dimensional fit, the result of which agrees with the Standard Model prediction. The data are interpreted in the context of a dimension-8 effective field theory to probe anomalous quartic gauge couplings resulting in the first set of exclusion limits on the Wilson coefficients in the semileptonic channel reported by the ATLAS Collaboration. The observed limits for the S02, T0 and M0 operators are $$(-\,3.96< f_{S02} / \Lambda ^4 < 3.96)$$ TeV $$^{-4}$$ , $$(-\,0.25< f_{T0} / \Lambda ^4 < 0.22)$$ TeV $$^{-4}$$ , $$(-\,1.26< f_{M0} / \Lambda ^4 < 1.25)$$ TeV $$^{-4}$$ . - Open Access
- 23 April 2026
- Published by Elsevier in Physics Letters B
- Vol. 877
Characterization of nuclear breakup as a function of hard-scattering kinematics using dijets measured by ATLAS in p+Pb collisions
- 23 April 2026
- Published by Elsevier in Physics Letters B
- Vol. 877
Open AccessCharacterization of nuclear breakup as a function of hard-scattering kinematics using dijets measured by ATLAS in p+Pb collisions
- Open Access
- 9 March 2026
- Published by Elsevier in Physics Letters B
- Vol. 877
Search for Higgs bosons produced in association with a high-energy photon via vector-boson fusion and decaying to a pair of b-quarks in the ATLAS detector
- 9 March 2026
- Published by Elsevier in Physics Letters B
- Vol. 877
Open AccessSearch for Higgs bosons produced in association with a high-energy photon via vector-boson fusion and decaying to a pair of b-quarks in the ATLAS detector
- Open Access
- 13 February 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (2)
Measurements of differential cross-sections of WbWb production in the dilepton channel in pp collisions at $ \sqrt{s}=13 $ TeV using the ATLAS detectorA bstract: At the Large Hadron Collider, the WbWb final state is expected to be dominated by $$ t\overline{t} $$ production with a contribution from single-top processes. Differential cross-sections for WbWb production in the dilepton decay channel are measured at the particle level as a function of various kinematic variables. The analysis is based on data from proton-proton collisions at a centre-of-mass energy of $$ \sqrt{s}=13 $$ TeV, recorded by the ATLAS detector at the Large Hadron Collider over the period from 2015 to 2018, corresponding to an integrated luminosity of 140 fb − 1 . Measurements are performed within the fiducial phase-space defined by the presence of two b -jets and one electron and one muon of opposite charges. The differential cross-sections are corrected for detector effects and unfolded to the particle level. Results are compared with predictions from Monte Carlo event generators at next-to-leading order in perturbative quantum chromodynamics; overall the measurements are in reasonable agreement with several generator setups, although no single prediction is able to describe all measured distributions simultaneously. These measurements provide valuable constraints on the modelling of WbWb production and the interference between doubly resonant and singly resonant WbWb production.- 13 February 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (2)
Open AccessMeasurements of differential cross-sections of WbWb production in the dilepton channel in pp collisions at $ \sqrt{s}=13 $ TeV using the ATLAS detectorA bstract: At the Large Hadron Collider, the WbWb final state is expected to be dominated by $$ t\overline{t} $$ production with a contribution from single-top processes. Differential cross-sections for WbWb production in the dilepton decay channel are measured at the particle level as a function of various kinematic variables. The analysis is based on data from proton-proton collisions at a centre-of-mass energy of $$ \sqrt{s}=13 $$ TeV, recorded by the ATLAS detector at the Large Hadron Collider over the period from 2015 to 2018, corresponding to an integrated luminosity of 140 fb − 1 . Measurements are performed within the fiducial phase-space defined by the presence of two b -jets and one electron and one muon of opposite charges. The differential cross-sections are corrected for detector effects and unfolded to the particle level. Results are compared with predictions from Monte Carlo event generators at next-to-leading order in perturbative quantum chromodynamics; overall the measurements are in reasonable agreement with several generator setups, although no single prediction is able to describe all measured distributions simultaneously. These measurements provide valuable constraints on the modelling of WbWb production and the interference between doubly resonant and singly resonant WbWb production. - Open Access
- 15 January 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (1) , 26
Erratum: Precision measurement of the $B^0$ meson lifetime using $B^0 \rightarrow J/\psi K^{*0}$ decays with the ATLAS detector- 15 January 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (1) , 26
Open AccessErratum: Precision measurement of the $B^0$ meson lifetime using $B^0 \rightarrow J/\psi K^{*0}$ decays with the ATLAS detector - Top Cited PapersOpen Access
- 14 January 2026
- Published by Springer Nature in Nature Communications
- Vol. 17 (1) , 541
Transforming jet flavour tagging at ATLAS
Jet flavour tagging enables the identification of jets originating from heavy-flavour quarks in proton–proton collisions at the Large Hadron Collider, playing a critical role in its physics programmes. This paper presents GN2, a transformer-based flavour tagging algorithm deployed by the ATLAS Collaboration that represents a different methodology compared to previous approaches. Designed to classify jets based on the flavour of their constituent particles, GN2 processes low-level tracking information in an end-to-end architecture and incorporates physics-informed auxiliary training objectives to enhance both interpretability and performance. Its performance is validated in both simulation and collision data. The measured c -jet (light-jet) rejection in data is improved by a factor of 3.5 (1.8) for a 70% b -jet tagging efficiency, compared to the previous algorithm. GN2 provides substantial benefits for physics analyses involving heavy-flavour jets, such as measurements of Higgs boson pair production and the couplings of bottom and charm quarks to the Higgs boson, and demonstrates the impact of advanced machine learning methods in experimental particle physics.
- 14 January 2026
- Published by Springer Nature in Nature Communications
- Vol. 17 (1) , 541
Top Cited PapersOpen AccessTransforming jet flavour tagging at ATLAS
Jet flavour tagging enables the identification of jets originating from heavy-flavour quarks in proton–proton collisions at the Large Hadron Collider, playing a critical role in its physics programmes. This paper presents GN2, a transformer-based flavour tagging algorithm deployed by the ATLAS Collaboration that represents a different methodology compared to previous approaches. Designed to classify jets based on the flavour of their constituent particles, GN2 processes low-level tracking information in an end-to-end architecture and incorporates physics-informed auxiliary training objectives to enhance both interpretability and performance. Its performance is validated in both simulation and collision data. The measured c -jet (light-jet) rejection in data is improved by a factor of 3.5 (1.8) for a 70% b -jet tagging efficiency, compared to the previous algorithm. GN2 provides substantial benefits for physics analyses involving heavy-flavour jets, such as measurements of Higgs boson pair production and the couplings of bottom and charm quarks to the Higgs boson, and demonstrates the impact of advanced machine learning methods in experimental particle physics.