Proton-proton elastic scattering at the LHC energy of s = 7 TeV The TOTEM Collaboration, G. Antchev, P. Aspell et al.Measurement of proton-proton elastic scattering and total cross-section at The TOTEM Collaboration, G. Antchev, P. Aspell et al.-LHC optics measurement with proton tracks detected by the Roman pots of the TOTEM experiment The TOTEM Collaboration, G Antchev, P Aspell et al. Abstract -TOTEM has measured the differential cross-section for elastic proton-proton scattering at the LHC energy of √ s = 7 TeV analysing data from a short run with dedicated large-β * optics. A single exponential fit with a slope B = (20.1 ± 0.2 stat ± 0.3 syst ) GeV −2 describes the range of the four-momentum transfer squared |t| from 0.02 to 0.33 GeV 2 . After the extrapolation to |t| = 0, a total elastic scattering cross-section of (24.8 ± 0.2 stat ± 1.2 syst ) mb was obtained. Applying the optical theorem and using the luminosity measurement from CMS, a total proton-proton cross-section of (98.3 ± 0.2 stat ± 2.8 syst ) mb was deduced which is in good agreement with the expectation from the overall fit of previously measured data over a large range of center-of-mass energies. From the total and elastic pp cross-section measurements, an inelastic pp cross-section of (73.5 ± 0.6open access editor's choice
21002-p1The TOTEM Collaboration (G. Antchev et al.) Introduction. -The observation of the rise of the total cross-section with energy was one of the highlights at the ISR, the first CERN collider [1][2][3][4]. Some indirect indications for this unforeseen phenomenon had already come earlier from high-energy cosmic-ray showers [5][6][7]. A long series of total proton-antiproton cross-section measurements followed in the last decades both at the CERN SppS collider [8,9] and at the TEVATRON [10][11][12][13].In this letter, we report the first measurement of the total and elastic proton-proton cross-sections at the CERN Large Hadron Collider (LHC) using the optical theorem together with the luminosity provided by the CMS experiment [14,15]. With a dedicated beam optics configuration (β * = 90 m) TOTEM has measured the differential crosssection of elastic scattering for four-momentum transfer squared values |t| to 2 × 10 −2 GeV 2 , making the extrapolation to the optical point at |t| = 0 possible. This allows the determination of the elastic scattering cross-section as well as the total cross-section.