著者

原 和彦 金 信弘 大川 英希 佐藤 構二 受川 史彦 ATLAS Collaboration Hara K. Kim S.H. Okawa H. Sato K. Ukegawa F.

出版者

American Physical Society

雑誌

Physical Review D (ISSN:24700010)

巻号頁・発行日

vol.97, no.5, 2018-03-27

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A search for electroweak production of supersymmetric particles in scenarios with compressed mass spectra in final states with two low-momentum leptons and missing transverse momentum is presented. This search uses proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider in 2015-2016, corresponding to 36.1 tb(-1) of integrated luminosity at root s = 13 TeV. Events with same flavor pairs of electrons or muons with opposite electric charge are selected. The data are found to be consistent with the Standard Model prediction. Results are interpreted using simplified models of R-parity conserving supersymmetry in which there is a small mass difference between the masses of the produced supersymmetric particles and the lightest neutralino. Exclusion limits at 95% confidence level are set on next-to-lightest neutralino masses of up to 145 GeV for Higgsino production and 175 GeV for wino production, and slepton masses of up to 190 GeV for pair production of sleptons. In the compressed mass regime, the exclusion limits extend down to mass splittings of 2.5 GeV for Higgsino production, 2 GeV for wino production, and 1 GeV for slepton production. The results are also interpreted in the context of a radiatively-driven natural supersymmetry model with nonuniversal Higgs boson masses.

著者

原 和彦 金 信弘 大川 英希 佐藤 構二 受川 史彦 ATLAS Collaboration Hara K. Kim S.H. Okawa H. Sato K. Ukegawa F.

出版者

American Physical Society

雑誌

Physical Review D (ISSN:24700010)

巻号頁・発行日

vol.98, no.3, 2018-08-15

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Results from a search for supersymmetry in events with four or more charged leptons (electrons, muons and taus) are presented. The analysis uses a data sample corresponding to 36.1 fb(-1) of proton-proton collisions delivered by the Large Hadron Collider at root s = 13 TeV and recorded by the ATLAS detector. Four-lepton signal regions with up to two hadronically decaying taus are designed to target a range of supersymmetric scenarios that can be either enriched in or depleted of events involving the production and decay of a Z boson. Data yields are consistent with Standard Model expectations and results are used to set upper limits on the event yields from processes beyond the Standard Model. Exclusion limits are set at the 95% confidence level in simplified models of general gauge mediated supersymmetry, where Higgsino masses are excluded up to 295 GeV. In R-parity-violating simplified models with decays of the lightest supersymmetric particle to charged leptons, lower limits of 1.46, 1.06, and 2.25 TeV are placed on wino, slepton and gluino masses, respectively.

著者

原 和彦 佐藤 構二 受川 史彦 ATLAS Collaboration Kazuhiko HARA Koji SATO Fumihiko UKEGAWA

出版者

American Physical Society

雑誌

Physical review D (ISSN:24700010)

巻号頁・発行日

vol.101, no.1, 2020-01

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Combined measurements of Higgs boson production cross sections and branching fractions are presented. The combination is based on the analyses of the Higgs boson decay modes H→γγ, ZZ∗, WW∗, ττ, b¯b, μμ, searches for decays into invisible final states, and on measurements of off-shell Higgs boson production. Up to 79.8  fb−1 of proton–proton collision data collected at √s=13  TeV with the ATLAS detector are used. Results are presented for the gluon–gluon fusion and vector-boson fusion processes, and for associated production with vector bosons or top-quarks. The global signal strength is determined to be μ=1.11+0.09−0.08. The combined measurement yields an observed (expected) significance for the vector-boson fusion production process of 6.5σ (5.3σ). Measurements in kinematic regions defined within the simplified template cross section framework are also shown. The results are interpreted in terms of modifiers applied to the Standard Model couplings of the Higgs boson to other particles, and are used to set exclusion limits on parameters in two-Higgs-doublet models and in the simplified minimal supersymmetric Standard Model. No significant deviations from Standard Model predictions are observed.

著者

Aidala C. Akiba Y. Alfred M. Andrieux V. Apadula N. Asano H. Azmoun B. Babintsev V. Bandara N. S. Barish K. N. Bathe S. Bazilevsky A. Beaumier M. Belmont R. Berdnikov A. Berdnikov Y. Blau D. S. Bok J. S. Brooks M. L. Bryslawskyj J. Bumazhnov V. Campbell S. Canoa Roman V. Cervantes R. Chi C. Y. Chiu M. Choi I. J. Choi J. B. Citron Z. Connors M. Cronin N. Csanád M. Csörgő T. Danley T. W. Daugherity M. S. David G. DeBlasio K. Dehmelt K. Denisov A. Deshpande A. Desmond E. J. Dion A. Dixit D. Do J. H. Drees A. Drees K. A. Durham J. M. Durum A. Enokizono A. En'yo H. Esumi S. Fadem B. Fan W. Feege N. Fields D. E. Finger M. Finger M. Fokin S. L. Frantz J. E. Franz A. Frawley A. D. Fukuda Y. Gal C. Gallus P. Gamez E. A. Garg P. Ge H. Giordano F. Goto Y. Grau N. Greene S. V. Grosse Perdekamp M. Gunji T. Guragain H. Hachiya T. Haggerty J. S. Hahn K. I. Hamagaki H. Hamilton H. F. Han S. Y. Hanks J. Hasegawa S. Haseler T. O. S. He X. Hemmick T. K. Hill J. C. Hill K. Hodges A. Hollis R. S. Homma K. Hong B. Hoshino T. Hotvedt N. Huang J. Huang S. Imai K. Inaba M. Iordanova A. Isenhower D. Ishimaru S. Ivanishchev D. Jacak B. V. Jezghani M. Ji Z. Jiang X. Johnson B. M. Jouan D. Jumper D. S. Kang J. H. Kapukchyan D. Karthas S. Kawall D. Kazantsev A. V. Khachatryan V. Khanzadeev A. Kim C. Kim E.-J. Kim M. Kincses D. Kistenev E. Klatsky J. Kline P. Koblesky T. Kotov D. Kudo S. Kurgyis B. Kurita K. Kwon Y. Lajoie J. G. Lebedev A. Lee S. Lee S. H. Leitch M. J. Leung Y. H. Lewis N. A. Li X. Lim S. H. Liu M. X. Loggins V.-R. Lökös S. Lovasz K. Lynch D. Majoros T. Makdisi Y. I. Makek M. Manko V. I. Mannel E. McCumber M. McGaughey P. L. McGlinchey D. McKinney C. Mendoza M. Metzger W. J. Mignerey A. C. Milov A. Mishra D. K. Mitchell J. T. Mitrankov Iu. Mitsuka G. Miyasaka S. Mizuno S. Montuenga P. Moon T. Morrison D. P. Morrow S. I. Murakami T. Murata J. Nagai K. Nagashima K. Nagashima T. Nagle J. L. Nagy M. I. Nakagawa I. Nakano K. Nattrass C. Nelson S. Niida T. Nishitani R. Nouicer R. Novák T. Novitzky N. Nyanin A. S. O'Brien E. Ogilvie C. A. Orjuela Koop J. D. Osborn J. D. Oskarsson A. Ottino G. J. Ozawa K. Pantuev V. Papavassiliou V. Park J. S. Park S. Pate S. F. Patel M. Peng W. Perepelitsa D. V. Perera G. D. N. Peressounko D. Yu. PerezLara C. E. Perry J. Petti R. Phipps M. Pinkenburg C. Pisani R. P. Pun A. Purschke M. L. Radzevich P. V. Read K. F. Reynolds D. Riabov V. Riabov Y. Richford D. Rinn T. Rolnick S. D. Rosati M. Rowan Z. Runchey J. Safonov A. S. Sakaguchi T. Sako H. Samsonov V. Sarsour M. Sato S. Scarlett C. Y. Schaefer B. Schmoll B. K. Sedgwick K. Seidl R. Sen A. Seto R. Sexton A. Sharma D. Shein I. Shibata T.-A. Shigaki K. Shimomura M. Shioya T. Shukla P. Sickles A. Silva C. L. Silvermyr D. Singh B. K. Singh C. P. Singh V. Skoby M. J. Slunečka M. Smith K. L. Snowball M. Soltz R. A. Sondheim W. E. Sorensen S. P. Sourikova I. V. Stankus P. W. Stoll S. P. Sugitate T. Sukhanov A. Sumita T. Sun J. Sun Z. Suzuki S. Sziklai J. Tanida K. Tannenbaum M. J. Tarafdar S. Taranenko A. Tarnai G. Tieulent R. Timilsina A. Todoroki T. Tomášek M. Towell C. L. Towell R. S. Tserruya I. Ueda Y. Ujvari B. van Hecke H. W. Velkovska J. Virius M. Vrba V. Vukman N. Wang X. R. Wang Z. Watanabe Y. S. Wong C. P. Woody C. L. Xu C. Xu Q. Xue L. Yalcin S. Yamaguchi Y. L. Yamamoto H. Yanovich A. Yoo J. H. Yoon I. Yu H. Yushmanov I. E. Zajc W. A. Zelenski A. Zhai Y. Zharko S. Zou L.

出版者

American Physical Society (APS)

雑誌

Physical Review D (ISSN:24700010)

巻号頁・発行日

no.99, 2019-05-13

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Measurements of the differential production of electrons from open-heavy-flavor hadrons with charm- and bottom-quark content in p+p collisions at √s=200 GeV are presented. The measurements proceed through displaced-vertex analyses of electron tracks from the semileptonic decay of charm and bottom hadrons using the PHENIX silicon-vertex detector. The relative contribution of electrons from bottom decays to inclusive heavy-flavor-electron production is found to be consistent with fixed-order-plus-next-to-leading-log perturbative-QCD calculations within experimental and theoretical uncertainties. These new measurements in p+p collisions provide a precision baseline for comparable forthcoming measurements in A+A collisions.