Elsevier

Physics Letters B

Volume 788, 10 January 2019, Pages 96-116
Physics Letters B

Search for heavy charged long-lived particles in proton–proton collisions at s=13TeV using an ionisation measurement with the ATLAS detector

https://doi.org/10.1016/j.physletb.2018.10.055Get rights and content
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Abstract

This Letter presents a search for heavy charged long-lived particles produced in proton–proton collisions at s=13TeV at the LHC using a data sample corresponding to an integrated luminosity of 36.1fb1 collected by the ATLAS experiment in 2015 and 2016. These particles are expected to travel with a velocity significantly below the speed of light, and therefore have a specific ionisation higher than any high-momentum Standard Model particle of unit charge. The pixel subsystem of the ATLAS detector is used in this search to measure the ionisation energy loss of all reconstructed charged particles which traverse the pixel detector. Results are interpreted assuming the pair production of R-hadrons as composite colourless states of a long-lived gluino and Standard Model partons. No significant deviation from Standard Model background expectations is observed, and lifetime-dependent upper limits on R-hadron production cross-sections and gluino masses are set, assuming the gluino always decays to two quarks and a 100 GeV stable neutralino. R-hadrons with lifetimes above 1.0 ns are excluded at the 95% confidence level, with lower limits on the gluino mass ranging between 1290 GeV and 2060 GeV. In the case of stable R-hadrons, the lower limit on the gluino mass at the 95% confidence level is 1890 GeV.

Cited by (0)

a

Also at Borough of Manhattan Community College, City University of New York, NY; United States of America.

b

Also at Centre for High Performance Computing, CSIR Campus, Rosebank, Cape Town; South Africa.

c

Also at CERN, Geneva; Switzerland.

d

Also at CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille; France.

e

Also at Département de Physique Nucléaire et Corpusculaire, Université de Genève, Genève; Switzerland.

f

Also at Departament de Fisica de la Universitat Autonoma de Barcelona, Barcelona; Spain.

g

Also at Departamento de Física Teorica y del Cosmos, Universidad de Granada, Granada (Spain); Spain.

h

Also at Department of Applied Physics and Astronomy, University of Sharjah, Sharjah; United Arab Emirates.

i

Also at Department of Financial and Management Engineering, University of the Aegean, Chios; Greece.

j

Also at Department of Physics and Astronomy, University of Louisville, Louisville, KY; United States of America.

k

Also at Department of Physics and Astronomy, University of Sheffield, Sheffield; United Kingdom.

l

Also at Department of Physics, California State University, Fresno CA; United States of America.

m

Also at Department of Physics, California State University, Sacramento CA; United States of America.

n

Also at Department of Physics, King's College London, London; United Kingdom.

o

Also at Department of Physics, St. Petersburg State Polytechnical University, St. Petersburg; Russia.

p

Also at Department of Physics, Stanford University; United States of America.

q

Also at Department of Physics, University of Fribourg, Fribourg; Switzerland.

r

Also at Department of Physics, University of Michigan, Ann Arbor MI; United States of America.

s

Also at Dipartimento di Fisica E. Fermi, Università di Pisa, Pisa; Italy.

t

Also at Giresun University, Faculty of Engineering, Giresun; Turkey.

u

Also at Graduate School of Science, Osaka University, Osaka; Japan.

v

Also at Hellenic Open University, Patras; Greece.

w

Also at Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest; Romania.

x

Also at II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen; Germany.

y

Also at Institucio Catalana de Recerca i Estudis Avancats, ICREA, Barcelona; Spain.

z

Also at Institut für Experimentalphysik, Universität Hamburg, Hamburg; Germany.

aa

Also at Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen; Netherlands.

ab

Also at Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Budapest; Hungary.

ac

Also at Institute of Particle Physics (IPP); Canada.

ad

Also at Institute of Physics, Academia Sinica, Taipei; Taiwan.

ae

Also at Institute of Physics, Azerbaijan Academy of Sciences, Baku; Azerbaijan.

af

Also at Institute of Theoretical Physics, Ilia State University, Tbilisi; Georgia.

ag

Also at Istanbul University, Dept. of Physics, Istanbul; Turkey.

ah

Also at LAL, Université Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay; France.

ai

Also at Louisiana Tech University, Ruston LA; United States of America.

aj

Also at Manhattan College, New York NY; United States of America.

ak

Also at Moscow Institute of Physics and Technology State University, Dolgoprudny; Russia.

al

Also at National Research Nuclear University MEPhI, Moscow; Russia.

am

Also at Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Freiburg; Germany.

an

Also at School of Physics, Sun Yat-sen University, Guangzhou; China.

ao

Also at The City College of New York, New York NY; United States of America.

ap

Also at The Collaborative Innovation Center of Quantum Matter (CICQM), Beijing; China.

aq

Also at Tomsk State University, Tomsk, and Moscow Institute of Physics and Technology State University, Dolgoprudny; Russia.

ar

Also at TRIUMF, Vancouver BC; Canada.

as

Also at Universita di Napoli Parthenope, Napoli; Italy.

Deceased.

E-mail address: [email protected].