# Measurement of inelastic, single- and double-diffraction cross sections in proton--proton collisions at the LHC with ALICE

Abstract : Measurements of cross sections of inelastic and diffractive processes in proton--proton collisions at LHC energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single diffraction (diffractive mass $M_X < 200$ GeV/$c^2$) $\sigma_{\rm SD}/\sigma_{\rm INEL} = 0.21 \pm 0.03, 0.20^{+0.07}_{-0.08}$, and $0.20^{+0.04}_{-0.07}$, respectively at centre-of-mass energies $\sqrt{s} = 0.9, 2.76$, and 7 TeV; for double diffraction (for a pseudorapidity gap $\Delta\eta > 3$) $\sigma_{\rm DD}/\sigma_{\rm INEL} = 0.11 \pm 0.03, 0.12 \pm 0.05$, and $0.12^{+0.05}_{-0.04}$, respectively at $\sqrt{s} = 0.9, 2.76$, and 7 TeV. To measure the inelastic cross section, beam properties were determined with van der Meer scans, and, using a simulation of diffraction adjusted to data, the following values were obtained: $\sigma_{\rm INEL} = 62.8^{+2.4}_{-4.0} (model) \pm 1.2 (lumi)$ mb at $\sqrt{s} =$ 2.76 TeV and $73.2^{+2.0}_{-4.6} (model) \pm 2.6 (lumi)$ mb at $\sqrt{s}$ = 7 TeV. The single- and double-diffractive cross sections were calculated combining relative rates of diffraction with inelastic cross sections. The results are compared to previous measurements at proton--antiproton and proton--proton colliders at lower energies, to measurements by other experiments at the LHC, and to theoretical models.
Document type :
Journal articles
European Physical Journal C: Particles and Fields, EDP Sciences: EPJ, 2013, 73, pp.2456. <10.1140/epjc/s10052-013-2456-0>
Domain :

http://hal.in2p3.fr/in2p3-00725471
Contributor : Dominique Girod <>
Submitted on : Monday, August 27, 2012 - 10:55:02 AM
Last modification on : Wednesday, February 18, 2015 - 1:05:26 AM

### Citation

B. Abelev, C. Cheshkov, B. Cheynis, L. Ducroux, J.-Y. Grossiord, et al.. Measurement of inelastic, single- and double-diffraction cross sections in proton--proton collisions at the LHC with ALICE. European Physical Journal C: Particles and Fields, EDP Sciences: EPJ, 2013, 73, pp.2456. <10.1140/epjc/s10052-013-2456-0>. <in2p3-00725471>

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