Search for metastable heavy charged particles with large ionisation energy loss in pp collisions at √s = 8 TeV using the ATLAS experiment

Allbrooke, B M M, Asquith, L, Cerri, A, Chavez Barajas, C A, De Santo, A, Salvatore, F, Santoyo Castillo, I, Suruliz, K, Sutton, M R, Vivarelli, I and The ATLAS Collaboration, (2015) Search for metastable heavy charged particles with large ionisation energy loss in pp collisions at √s = 8 TeV using the ATLAS experiment. European Physical Journal C: Particles and Fields, 75 (9). p. 407. ISSN 1434-6044

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Abstract

Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as R-hadrons or charginos. These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.6 ns to 30 ns. A search for such particles with the ATLAS detector at the Large Hadron Collider is presented, based on a data sample corresponding to an integrated luminosity of 18.4 8.4 fb −1 −1 of pp collisions at s √ =8 s=8 TeV. No significant deviation from the Standard Model background expectation is observed, and lifetime-dependent upper limits on R-hadrons and chargino production are set. Gluino R-hadrons with 10 ns lifetime and masses up to 1185 GeV are excluded at 95 % % confidence level, and so are charginos with 15 ns lifetime and masses up to 482 GeV.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups: Experimental Particle Physics Research Group
Subjects: Q Science > QC Physics
Depositing User: Richard Chambers
Date Deposited: 15 Feb 2017 09:41
Last Modified: 07 Mar 2017 03:45
URI: http://sro.sussex.ac.uk/id/eprint/66755

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Project NameSussex Project NumberFunderFunder Ref
STFC Consolidated Grant SupplementG1316STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCILST/M000753/1