The process pp → pℓ+ℓ−p(*), with ℓ+ℓ− a muon or an electron pair produced at midrapidity with mass larger than 110 GeV, has been observed for the first time at the LHC in pp collisions at s=13 TeV. One of the two scattered protons is measured in the CMS-TOTEM precision proton spectrometer (CT-PPS), which operated for the first time in 2016. The second proton either remains intact or is excited and then dissociates into a low-mass state p*, which is undetected. The measurement is based on an integrated luminosity of 9.4 fb−1 collected during standard, high-luminosity LHC operation. A total of 12 μ+μ− and 8 e+e− pairs with m(ℓ+ℓ−) > 110 GeV, and matching forward proton kinematics, are observed, with expected backgrounds of 1.49 ± 0.07 (stat) ± 0.53 (syst) and 2.36 ± 0.09 (stat) ± 0.47 (syst), respectively. This corresponds to an excess of more than five standard deviations over the expected background. The present result constitutes the first observation of proton-tagged γγ collisions at the electroweak scale. This measurement also demonstrates that CT-PPS performs according to the design specifications.[Figure not available: see fulltext.].

Sirunyan, A., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., et al. (2018). Observation of proton-tagged, central (semi)exclusive production of high-mass lepton pairs in pp collisions at 13 TeV with the CMS-TOTEM precision proton spectrometer. JOURNAL OF HIGH ENERGY PHYSICS, 2018(7), 1-45 [10.1007/JHEP07(2018)153].

Observation of proton-tagged, central (semi)exclusive production of high-mass lepton pairs in pp collisions at 13 TeV with the CMS-TOTEM precision proton spectrometer

Battilana, C.;Bonacorsi, D.;Borgonovi, L.;Braibant-Giacomelli, S.;Castro, A.;Cuffiani, M.;Fanfani, A.;Fasanella, D.;Guiducci, L.;Iemmi, F.;Rovelli, T.;Siroli, G. P.;
2018

Abstract

The process pp → pℓ+ℓ−p(*), with ℓ+ℓ− a muon or an electron pair produced at midrapidity with mass larger than 110 GeV, has been observed for the first time at the LHC in pp collisions at s=13 TeV. One of the two scattered protons is measured in the CMS-TOTEM precision proton spectrometer (CT-PPS), which operated for the first time in 2016. The second proton either remains intact or is excited and then dissociates into a low-mass state p*, which is undetected. The measurement is based on an integrated luminosity of 9.4 fb−1 collected during standard, high-luminosity LHC operation. A total of 12 μ+μ− and 8 e+e− pairs with m(ℓ+ℓ−) > 110 GeV, and matching forward proton kinematics, are observed, with expected backgrounds of 1.49 ± 0.07 (stat) ± 0.53 (syst) and 2.36 ± 0.09 (stat) ± 0.47 (syst), respectively. This corresponds to an excess of more than five standard deviations over the expected background. The present result constitutes the first observation of proton-tagged γγ collisions at the electroweak scale. This measurement also demonstrates that CT-PPS performs according to the design specifications.[Figure not available: see fulltext.].
2018
Sirunyan, A., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., et al. (2018). Observation of proton-tagged, central (semi)exclusive production of high-mass lepton pairs in pp collisions at 13 TeV with the CMS-TOTEM precision proton spectrometer. JOURNAL OF HIGH ENERGY PHYSICS, 2018(7), 1-45 [10.1007/JHEP07(2018)153].
Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Escalante Del...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/664264
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