This Letter presents a search for the production of a long-lived neutral particle (Z(d)) decaying within the ATLAS hadronic calorimeter, in association with a standard model (SM) Z boson produced via an intermediate scalar boson, where Z -> l(+) l(-) (l = e, mu). The data used were collected by the ATLAS detector during 2015 and 2016 pp collisions with a center-of-mass energy of root s = 13 TeV at the Large Hadron Collider and correspond to an integrated luminosity of 36.1 +/- 0.8 fb(-1). No significant excess of events is observed above the expected background. Limits on the production cross section of the scalar boson times its decay branching fraction into the long-lived neutral particle are derived as a function of the mass of the intermediate scalar boson, the mass of the long-lived neutral particle, and its c tau from a few centimeters to one hundred meters. In the case that the intermediate scalar boson is the SM Higgs boson, its decay branching fraction to a long-lived neutral particle with a c tau approximately between 0.1 and 7 m is excluded with a 95% confidence level up to 10% for m(zd) between 5 and 15 GeV.

Search for the Production of a Long-Lived Neutral Particle Decaying within the ATLAS Hadronic Calorimeter in Association with a Z Boson from pp Collisions at root s=13 TeV / Aaboud, M., Aad, G., Abbott, B., Abdinov, O., Abeloos, B., Abhayasinghe, D.K., Abidi, S.H., Abouzeid, O.S., Abraham, N.L., Abramowicz, H., Abreu, H., Abulaiti, Y., Acharya, B.S., Adachi, S., Adam, L., Adamczyk, L., Adelman, J., Adersberger, M., Adiguzel, A., Adye, T., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 122:15(2019). [10.1103/PhysRevLett.122.151801]

Search for the Production of a Long-Lived Neutral Particle Decaying within the ATLAS Hadronic Calorimeter in Association with a Z Boson from pp Collisions at root s=13 TeV

Artoni, G.;Bagnaia, P.;Betti, A.;Bini, C.;De Cecco, S.;Gentile, S.;Giagu, S.;Kado, M.;Lacava, F.;Luci, C.;Messina, A.;Policicchio, A.;Sebastiani, C. D.;
2019

Abstract

This Letter presents a search for the production of a long-lived neutral particle (Z(d)) decaying within the ATLAS hadronic calorimeter, in association with a standard model (SM) Z boson produced via an intermediate scalar boson, where Z -> l(+) l(-) (l = e, mu). The data used were collected by the ATLAS detector during 2015 and 2016 pp collisions with a center-of-mass energy of root s = 13 TeV at the Large Hadron Collider and correspond to an integrated luminosity of 36.1 +/- 0.8 fb(-1). No significant excess of events is observed above the expected background. Limits on the production cross section of the scalar boson times its decay branching fraction into the long-lived neutral particle are derived as a function of the mass of the intermediate scalar boson, the mass of the long-lived neutral particle, and its c tau from a few centimeters to one hundred meters. In the case that the intermediate scalar boson is the SM Higgs boson, its decay branching fraction to a long-lived neutral particle with a c tau approximately between 0.1 and 7 m is excluded with a 95% confidence level up to 10% for m(zd) between 5 and 15 GeV.
2019
hadron colliders, Hypothetical gauge bosons, particle decays
01 Pubblicazione su rivista::01a Articolo in rivista
Search for the Production of a Long-Lived Neutral Particle Decaying within the ATLAS Hadronic Calorimeter in Association with a Z Boson from pp Collisions at root s=13 TeV / Aaboud, M., Aad, G., Abbott, B., Abdinov, O., Abeloos, B., Abhayasinghe, D.K., Abidi, S.H., Abouzeid, O.S., Abraham, N.L., Abramowicz, H., Abreu, H., Abulaiti, Y., Acharya, B.S., Adachi, S., Adam, L., Adamczyk, L., Adelman, J., Adersberger, M., Adiguzel, A., Adye, T., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 122:15(2019). [10.1103/PhysRevLett.122.151801]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1306043
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