Abstract
Preliminary LHC results on proton-tagged measurements of Single Diffractive Dissociation (pp → pX) are presented from ATLAS using s=8 TeV data. The central ATLAS detector is used to reconstruct the dissociative X system, and the forward spectrometer ALFA is used to tag the intact proton. Differential cross sections are measured as a function of ξ, the fractional energy loss of the intact proton; |t|, the squared four-momentum exchanged and Δη, the observable rapidity gap. The unfolded t differential cross section is consistent with an exponential dependence dσ/dt ∝ eBt with a slope parameter B = 7.60 ± 0.32 GeV−2. The unfolded ξ differential cross section is interpreted in the framework of Regge phenomenology to extract a Pomeron intercept of α(0) = 1.07 ± 0.09.
Highlights
Single diffractive dissociation (SD) in proton proton collisions results in one proton remaining intact and the other dissociating into the diffractive system X
The event variable ∆η is defined as the rapidity gap between the edge of the inner tracking detector (ID) tracker (|η| = 2.5) on the side of the proton tag and the nearest ID track with pT > 200 MeV
The large number of events in the first few bins is understood to be due to the limited η coverage of the ID
Summary
Single diffractive dissociation (SD) in proton proton collisions (pp → pX) results in one proton remaining intact and the other dissociating into the diffractive system X. James Kendrick / Nuclear and Particle Physics Proceedings 00 (2019) 1–6 at LHC energies was not well constrained despite making a large (∼10-20%) contribution to the total protonproton cross section. Both ATLAS and CMS have previously published measurements on diffractive cross sections by exploiting the characteristic large rapidity gap seen in such events [1, 2]. Neither does it allow measurement of the dynamics within an SD event such as |t| or ξ
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
