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.].

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 / Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., Brandstetter, J., Brondolin, E., Dragicevic, M., Ero, J., Escalante Del Valle, A., Flechl, M., Friedl, M., Fruhwirth, R., Ghete, V.M., Grossmann, J., Hrubec, J., Jeitler, M., Konig, A., Krammer, N., et al.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1126-6708. - 2018:7(2018). [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

Cipriani M.;Del Re D.;Longo E.;Organtini G.;Paramatti R.;Rahatlou S.;Santanastasio F.;
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
forward physics; hadron-hadron scattering (experiments); photon production; proton-proton scattering
01 Pubblicazione su rivista::01a Articolo in rivista
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 / Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., Brandstetter, J., Brondolin, E., Dragicevic, M., Ero, J., Escalante Del Valle, A., Flechl, M., Friedl, M., Fruhwirth, R., Ghete, V.M., Grossmann, J., Hrubec, J., Jeitler, M., Konig, A., Krammer, N., et al.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1126-6708. - 2018:7(2018). [10.1007/JHEP07(2018)153]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1356769
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