Alexander Tapper

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, Brandstetter J, Dragicevic M, Eroe J, Del Valle AE, Flechl M, Fruehwirth R, Ghete VM, Hrubec J, Jeitler M, Krammer N, Kraetschmer I, Liko D, Madlener T, Mikulec I, Rad N, Rohringer H, Schieck J, Schoefbeck R, Spanring M, Spitzbart D, Taurok A, Waltenberger W, Wittmann J, Wulz C-E, Zarucki M, Chekhovsky V, Mossolov V, Gonzalez JS, De Wolf EA, Di Croce D, Janssen X, Lauwers J, Pieters M, Van Haevermaet H, Van Mechelen P, Van Remortel N, Abu Zeid S, Blekman F, D'Hondt J, De Clercq J, Deroover K, Flouris G, Lontkovskyi D, Lowette S, Marchesini I, Moortgat S, Moreels L, Python Q, Skovpen K, Tavernier S, Van Doninck W, Van Mulders P, Van Parijs I, Beghin D, Bilin B, Brun H, Clerbaux B, De Lentdecker G, Delannoy H, Dorney B, Fasanella G, Favart L, Goldouzian R, Grebenyuk A, Kalsi AK, Lenzi T, Luetic J, Postiau N, Starling E, Thomas L, Vander Velde C, Vanlaer P, Vannerom D, Wang Q, Cornelis T, Dobur D, Fagot A, Gul M, Khvastunov I, Poyraz D, Roskas C, Trocino D, Tytgat M, Verbeke W, Vermassen B, Vit M, Zaganidis N, Bakhshiansohi H, Bondu O, Brochet S, Bruno G, David P, Delaere C, Delcourt M, Francois B, Giammanco A, Krintiras G, Lemaitre V, Magitteri A, Piotrzkowski K, Saggio A, Marono MV, Wertz S, Zobec J, Alves FL, Alves GA, Correa Martins M, Correia Silva G, Hensel C, Moraes A, Pol ME, Rebello Teles P, Belchior Batista Das Chagas E, Carvalho W, Chinellato J, Coelho E, Da Costa EM, Da Silveira GG, De Jesus Damiao D, De Oliveira Martins C, Fonseca De Souza S, Malbouisson H, Matos Figueiredo D, Melo De Almeida M, Mora Herrera C, Mundim L, Nogima H, Prado Da Silva WL, Sanchez Rosas LJ, Santoro A, Sznajder A, Thiel M, Tonelli Manganote EJ, Torres Da Silva De Araujo F, Vilela Pereira A, Ahuja S, Bernardes CA, Calligaris L, Fernandez Perez Tomei TR, Gregores EM, Mercadante PG, Novaes SF, Padula S, Aleksandrov A, Hadjiiska R, Iaydjiev P, Marinov A, Misheva M, Rodozov M, Shopova M, Sultanov G, Dimitrov A, Litov Let al., 2019, Search for contact interactions and large extra dimensions in the dilepton mass spectra from proton-proton collisions at root s=13 TeV, Journal of High Energy Physics, Vol: 114, ISSN: 1029-8479

A search for nonresonant excesses in the invariant mass spectra of electron and muon pairs is presented. The analysis is based on data from proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the CMS experiment in 2016, corresponding to a total integrated luminosity of 36 fb−1. No significant deviation from the standard model is observed. Limits are set at 95% confidence level on energy scales for two general classes of nonresonant models. For a class of fermion contact interaction models, lower limits ranging from 20 to 32 TeV are set on the characteristic compositeness scale Λ. For the Arkani-Hamed, Dimopoulos, and Dvali model of large extra dimensions, the first results in the dilepton final state at 13 TeV are reported, and values of the ultraviolet cutoff parameter ΛT below 6.9 TeV are excluded. A combination with recent CMS diphoton results improves this exclusion to ΛT below 7.7 TeV, providing the most sensitive limits to date in nonhadronic final states.

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Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, Brandstetter J, Dragicevic M, Eroe J, Del Valle AE, Flechl M, Fruehwirth R, Ghete VM, Hrubec J, Jeitler M, Krammer N, Kraetschmer I, Liko D, Madlener T, Mikulec I, Rad N, Rohringer H, Schieck J, Schoefbeck R, Spanring M, Spitzbart D, Taurok A, Waltenberger W, Wittmann J, Wulz C-E, Zarucki M, Chekhovsky V, Mossolov V, Gonzalez JS, De Wolf EA, Di Croce D, Janssen X, Lauwers J, Pieters M, Van Haevermaet H, Van Mechelen P, Van Remortel N, Abu Zeid S, Blekman F, D'Hondt J, De Clercq J, Deroover K, Flouris G, Lontkovskyi D, Lowette S, Marchesini I, Moortgat S, Moreels L, Python Q, Skovpen K, Tavernier S, Van Doninck W, Van Mulders P, Van Parijs I, Beghin D, Bilin B, Brun H, Clerbaux B, De Lentdecker G, Delannoy H, Dorney B, Fasanella G, Favart L, Goldouzian R, Grebenyuk A, Kalsi AK, Lenzi T, Luetic J, Postiau N, Starling E, Thomas L, Vander Velde C, Vanlaer P, Vannerom D, Wang Q, Cornelis T, Dobur D, Fagot A, Gul M, Khvastunov I, Poyraz D, Roskas C, Trocino D, Tytgat M, Verbeke W, Vermassen B, Vit M, Zaganidis N, Bakhshiansohi H, Bondu O, Brochet S, Bruno G, David P, Delaere C, Delcourt M, Francois B, Giammanco A, Krintiras G, Lemaitre V, Magitteri A, Piotrzkowski K, Saggio A, Marono MV, Wertz S, Zobec J, Alves FL, Alves GA, Correa Martins M, Correia Silva G, Hensel C, Moraes A, Pol ME, Rebello Teles P, Belchior Batista Das Chagas E, Carvalho W, Chinellato J, Coelho E, Da Costa EM, Da Silveira GG, De Jesus Damiao D, De Oliveira Martins C, Fonseca De Souza S, Malbouisson H, Matos Figueiredo D, Melo De Almeida M, Mora Herrera C, Mundim L, Nogima H, Prado Da Silva WL, Sanchez Rosas LJ, Santoro A, Sznajder A, Thiel M, Tonelli Manganote EJ, Torres Da Silva De Araujo F, Vilela Pereira A, Ahuja S, Bernardes CA, Calligaris L, Fernandez Perez Tomei TR, Gregores EM, Mercadante PG, Novaes SF, Padula S, Aleksandrov A, Hadjiiska R, Iaydjiev P, Marinov A, Misheva M, Rodozov M, Shopova M, Sultanov G, Dimitrov A, Litov Let al., 2019, Search for nonresonant Higgs boson pair production in the b(b)over-barb(b)over-bar final state at root s=13 TeV, Journal of High Energy Physics, Vol: 2019, ISSN: 1029-8479

Results of a search for nonresonant production of Higgs boson pairs, with each Higgs boson decaying to a bb¯¯¯ pair, are presented. This search uses data from proton-proton collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1, collected by the CMS detector at the LHC. No signal is observed, and a 95% confidence level upper limit of 847 fb is set on the cross section for standard model nonresonant Higgs boson pair production times the squared branching fraction of the Higgs boson decay to a bb¯¯¯ pair. The same signature is studied, and upper limits are set, in the context of models of physics beyond the standard model that predict modified couplings of the Higgs boson.

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Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, Brandstetter J, Dragicevic M, Eroe J, Del Valle AE, Flechl M, Fruehwirth R, Ghete VM, Hrubec J, Jeitler M, Krammer N, Kraetschmer I, Liko D, Madlener T, Mikulec I, Rad N, Rohringer H, Schieck J, Schoefbeck R, Spanring M, Spitzbart D, Taurok A, Waltenberger W, Wittmann J, Wulz C-E, Zarucki M, Chekhovsky V, Mossolov V, Gonzalez JS, De Wolf EA, Di Croce D, Janssen X, Lauwers J, Pieters M, Van Haevermaet H, Van Mechelen P, Van Remortel N, Abu Zeid S, Blekman F, D'Hondt J, De Bruyn I, De Clercq J, Deroover K, Flouris G, Lontkovskyi D, Lowette S, Marchesini I, Moortgat S, Moreels L, Python Q, Skovpen K, Tavernier S, Van Doninck W, Van Mulders P, Van Parijs I, Beghin D, Bilin B, Brun H, Clerbaux B, De Lentdecker G, Delannoy H, Dorney B, Fasanella G, Favart L, Goldouzian R, Grebenyuk A, Kalsi AK, Lenzi T, Luetic J, Postiau N, Starling E, Thomas L, Vander Velde C, Vanlaer P, Vannerom D, Wang Q, Cornelis T, Dobur D, Fagot A, Gul M, Khvastunov I, Poyraz D, Roskas C, Trocino D, Tytgat M, Verbeke W, Vermassen B, Vit M, Zaganidis N, Bakhshiansohi H, Bondu O, Brochet S, Bruno G, Caputo C, David P, Delaere C, Delcourt M, Giammanco A, Krintiras G, Lemaitre V, Magitteri A, Mertens A, Musich M, Piotrzkowski K, Saggio A, Marono MV, Wertz S, Zobec J, Alves FL, Alves GA, Correa Martins Junior M, Correia Silva G, Hensel C, Moraes A, Pol ME, Rebello Teles P, Belchior Batista Das Chagas E, Carvalho W, Chinellato J, Coelho E, Da Costa EM, Da Silveira GG, De Jesus Damiao D, De Oliveira Martins C, Fonseca De Souza S, Malbouisson H, Matos Figueiredo D, Melo De Almeida M, Mora Herrera C, Mundim L, Nogima H, Prado Da Silva WL, Sanchez Rosas LJ, Santoro A, Sznajder A, Thiel M, Tonelli Manganote EJ, Torres Da Silva De Araujo F, Vilela Pereira A, Ahuja S, Bernardes CA, Calligaris L, Fernandez Perez Tomei TR, Gregores EM, Mercadante PG, Novaes SF, Padula SS, Aleksandrov A, Hadjiiska R, Iaydjiev P, Marinov A, Misheva M, Rodozov M, Shopoet al., 2019, Observation of prompt J/ψ meson elliptic flow in high-multiplicity pPb collisions at √sNN = 8.16 TeV, Physics Letters B, Vol: 791, Pages: 172-194, ISSN: 0370-2693

A measurement of the elliptic flow (v2) of prompt J/ψ mesons in high multiplicity pPb collisions is reported using data collected by the CMS experiment at a nucleon-nucleon center-of-mass energy √sNN = 8.16 TeV. Prompt J/ψ mesons decaying into two muons are reconstructed in the rapidity region in the nucleon-nucleon center-of-mass frame (ycm), corresponding to either −2.86 < ycm < −1.86 or 0.94 < ycm < 1.94. The average v2 result from the two rapidity ranges is reported over the transverse momentum (pT) range from 0.2 to 10 GeV. Positive v2 values are observed for the prompt J/ψ meson, as extracted from long-range two-particle correlations with charged hadrons, for 2 < pT < 8 GeV. The prompt J/ψ results are compared with previous CMS measurements of elliptic flow for open charm mesons (D0) and strange hadrons. From these measurements, constraints can be obtained on the collective dynamics of charm quarks produced in high-multiplicity events arising from small systems.

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Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, Brandstetter J, Dragicevic M, Eroe J, Del Valle AE, Flechl M, Fruehwirth R, Ghete VM, Hrubec J, Jeitler M, Krammer N, Kraetschmer I, Liko D, Madlener T, Mikulec I, Rad N, Rohringer H, Schieck J, Schoefbeck R, Spanring M, Spitzbart D, Taurok A, Waltenberger W, Wittmann J, Wulz C-E, Zarucki M, Chekhovsky V, Mossolov V, Gonzalez JS, De Wolf EA, Di Croce D, Janssen X, Lauwers J, Pieters M, Van De Klundert M, Van Haevermaet H, Van Mechelen P, Van Remortel N, Abu Zeid S, Blekman F, D'Hondt J, De Bruyn I, De Clercq J, Deroover K, Flouris G, Lontkovskyi D, Lowette S, Marchesini I, Moortgat S, Moreels L, Python Q, Skovpen K, Tavernier S, Van Doninck W, Van Mulders P, Van Parijs I, Beghin D, Bilin B, Brun H, Clerbaux B, De Lentdecker G, Delannoy H, Dorney B, Fasanella G, Favart L, Goldouzian R, Grebenyuk A, Kalsi AK, Lenzi T, Luetic J, Postiau N, Starling E, Thomas L, Vander Velde C, Vanlaer P, Vannerom D, Wang Q, Cornelis T, Dobur D, Fagot A, Gul M, Khvastunov I, Poyraz D, Roskas C, Trocino D, Tytgat M, Verbeke W, Vermassen B, Vit M, Zaganidis N, Bakhshiansohi H, Bondu O, Brochet S, Bruno G, Caputo C, David P, Delaere C, Delcourt M, Francois B, Giammanco A, Krintiras G, Lemaitre V, Magitteri A, Mertens A, Musich M, Piotrzkowski K, Saggio A, Marono MV, Wertz S, Zobec J, Alves FL, Alves GA, Brito L, Correa Martins Junior M, Correia Silva G, Hensel C, Moraes A, Pol ME, Rebello Teles P, Belchior Batista Das Chagas E, Carvalho W, Chinellato J, Coelho E, Da Costa EM, Da Silveira GG, De Jesus Damiao D, De Oliveira Martins C, Fonseca De Souza S, Malbouisson H, Matos Figueiredo D, Melo De Almeida M, Mora Herrera C, Mundim L, Nogima H, Prado Da Silva WL, Sanchez Rosas LJ, Santoro A, Sznajder A, Thiel M, Tonelli Manganote EJ, Torres Da Silva De Araujo F, Vilela Pereira A, Ahuja S, Bernardes CA, Calligaris L, Fernandez Perez Tomei TR, Gregores EM, Mercadante PG, Novaes SF, Padula SS, Romero Abad D, Aleksandrov A, Hadjiisket al., 2019, Measurements of properties of the Higgs boson decaying to a W boson pair in pp collisions at √s =13 TeV, Physics Letters B, Vol: 791, Pages: 96-129, ISSN: 0370-2693

Measurements of the production of the standard model Higgs boson decaying to a W boson pair are reported. The W+W− candidates are selected in events with an oppositely charged lepton pair, large missing transverse momentum, and various numbers of jets. To select Higgs bosons produced via vector boson fusion and associated production with a W or Z boson, events with two jets or three or four leptons are also selected. The event sample corresponds to an integrated luminosity of 35.9 fb−1, collected in pp collisions at √s = 13 TeV by the CMS detector at the LHC during 2016. Combining all channels, the observed cross section times branching fraction is 1.28+0.18 −0.17 times the standard modelprediction for the Higgs boson with a mass of 125.09 GeV. This is the first observation of the Higgs boson decay to W boson pairs by the CMS experiment.

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Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, Brandstetter J, Dragicevic M, Eroe J, Del Valle AE, Flechl M, Fruehwirth R, Ghete VM, Hrubec J, Jeitler M, Krammer N, Kraetschmer I, Liko D, Madlener T, Mikulec I, Rad N, Rohringer H, Schieck J, Schoefbeck R, Spanring M, Spitzbart D, Waltenberger W, Wittmann J, Wulz C-E, Zarucki M, Chekhovsky V, Mossolov V, Gonzalez JS, De Wolf EA, Di Croce D, Janssen X, Lauwers J, Lelek A, Pieters M, Van Haevermaet H, Van Mechelen P, Van Remortel N, Blekman F, D'Hondt J, De Clercq J, Deroover K, Flouris G, Lontkovskyi D, Lowette S, Marchesini I, Moortgat S, Moreels L, Python Q, Skovpen K, Tavernier S, Van Doninck W, Van Mulders P, Van Parijs I, Beghin D, Bilin B, Brun H, Clerbaux B, De Lentdecker G, Delannoy H, Dorney B, Fasanella G, Favart L, Grebenyuk A, Kalsi AK, Luetic J, Popov A, Postiau N, Starling E, Thomas L, Vander Velde C, Vanlaer P, Vannerom D, Wang Q, Cornelis T, Dobur D, Fagot A, Gul M, Khvastunov I, Roskas C, Trocino D, Tytgat M, Verbeke W, Vermassen B, Vit M, Zaganidis N, Bondu O, Bruno G, Caputo C, David P, Delaere C, Delcourt M, Giammanco A, Krintiras G, Lemaitre V, Magitteri A, Piotrzkowski K, Saggio A, Marono MV, Vischia P, Zobec J, Alves FL, Alves GA, Correia Silva G, Hensel C, Moraes A, Pol ME, Rebello Teles P, Belchior Batista Das Chagas E, Carvalho W, Chinellato J, Coelho E, Da Costa EM, Da Silveira GG, De Jesus Damiao D, De Oliveira Martins C, Fonseca De Souza S, Huertas Guativa LM, Malbouisson H, Matos Figueiredo D, Melo De Almeida M, Mora Herrera C, Mundim L, Nogima H, Prado Da Silva WL, Sanchez Rosas LJ, Santoro A, Sznajder A, Thiel M, Tonelli Manganote EJ, Torres Da Silva De Araujo F, Vilela Pereira A, Ahuja S, Bernardes CA, Calligaris L, Fernandez Perez Tomei TR, Gregores EM, Mercadante PG, Novaes SF, Padula SS, Aleksandrov A, Hadjiiska R, Iaydjiev P, Marinov A, Misheva M, Rodozov M, Shopova M, Sultanov G, Dimitrov A, Litov L, Pavlov B, Petkov P, Fang W, Gao X, Yuan L, Ahmad M, Bian JG Cet al., 2019, Observation of Single Top Quark Production in Association with a Z Boson in Proton-Proton Collisions at √s =13 TeV, Physical Review Letters, Vol: 122, ISSN: 0031-9007

The observation of single top quark production in association with a Z boson and a quark (tZq) is reported. Events from proton-proton collisions at a center-of-mass energy of 13 TeV containing three charged leptons (either electrons or muons) and at least two jets are analyzed. The data were collected with the CMS detector in 2016 and 2017 and correspond to an integrated luminosity of 77.4fb−1. The increased integrated luminosity, a multivariate lepton identification, and a redesigned analysis strategy improve significantly the sensitivity of the analysis compared to previous searches for tZq production. The tZq signal is observed with a significance well over 5 standard deviations. The measured tZq production cross section is σ(pp→tZq→tℓ+ℓ−q) = 111±13(stat)+11−9(syst) fb , for dilepton invariant masses above 30 GeV, in agreement with the standard model expectation.

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