Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
Creators: name: Alimena, Juliette
name: Beacham, James
name: Borsato, Martino
name: Cheng, Yangyang
name: Vidal, Xabier Cid
name: Cottin, Giovanna
name: De Roeck, Albert
name: Desai, Nishita
name: Curtin, David
name: Evans, Jared A.
name: Knapen, Simon
name: Kraml, Sabine
name: Lessa, Andre
name: Liu, Zhen
name: Mehlhase, Sascha
name: Ramsey-Musolf, Michael J.
name: Russell, Heather
name: Shelton, Jessie
name: Shuve, Brian
name: Verducci, Monica
name: Zurita, Jose
name: Adams, Todd
name: Adersberger, Michael
name: Alpigiani, Cristiano
name: Apresyan, Artur
name: Bainbridge, Robert John
name: Batozskaya, Varvara
name: Beauchesne, Hugues
name: Benato, Lisa
name: Berlendis, S.
name: Bhal, Eshwen
name: Blekman, Freya
name: Borovilou, Christina
name: Boyd, Jamie
name: Brau, Benjamin P.
name: Bryngemark, Lene
name: Buchmueller, Oliver
name: Buschmann, Malte
name: Buttinger, William
name: Campanelli, Mario
name: Cesarotti, Cari
name: Chen, Chunhui
name: Cheng, Hsin-Chia
name: Cheong, Sanha
name: Citron, Matthew
name: Coccaro, Andrea
name: Coco, V.
name: Conte, Eric
name: Cormier, Félix
name: Corpe, Louie D.
name: Craig, Nathaniel
name: Cui, Yanou
name: Dall'Occo, Elena
name: Dallapiccola, C.
name: Darwish, M. R.
name: Davoli, Alessandro
name: de Cosa, Annapaola
name: De Simone, Andrea
name: Rose, Luigi Delle
name: Deppisch, Frank F.
name: Dey, Biplab
name: Diamond, Miriam D.
name: Dienes, Keith R.
name: Dildick, Sven
name: Döbrich, Babette
name: Drewes, Marco
name: Eich, Melanie
name: ElSawy, M.
name: del Valle, Alberto Escalante
name: Facini, Gabriel
name: Farina, Marco
name: Feng, Jonathan L.
name: Fischer, Oliver
name: Flaecher, H. U.
name: Foldenauer, Patrick
name: Freytsis, Marat
name: Fuks, Benjamin
name: Galon, Iftah
name: Gershtein, Yuri
name: Giagu, Stefano
name: Giammanco, Andrea
name: Gligorov, Vladimir V.
name: Golling, Tobias
name: Grancagnolo, Sergio
name: Gustavino, Giuliano
name: Haas, Andrew
name: Hahn, Kristian
name: Hajer, Jan
name: Hammad, Ahmed
name: Heinrich, Lukas
name: Heisig, Jan
name: Helo, J. C.
name: Hesketh, Gavin
name: Hill, Christopher S.
name: Hirsch, Martin
name: Hohlmann, M.
name: Hulsbergen, W.
name: Huth, John
name: Ilten, Philip
name: Jacques, Thomas
name: Jayatilaka, Bodhitha
name: Jeng, Geng-Yuan
name: Johns, K. A.
name: Kaji, Toshiaki
name: Kasieczka, Gregor
name: Kats, Yevgeny
name: Kazana, Malgorzata
name: Keller, Henning
name: Khlopov, Maxim Yu.
name: Kling, Felix
name: Kolberg, Ted R.
name: Kostiuk, Igor
name: Kuwertz, Emma Sian
name: Kvam, Audrey
name: Landsberg, Greg
name: Lanfranchi, Gaia
name: Lara, Iñaki
name: Ledovskoy, Alexander
name: Linthorne, Dylan
name: Liu, Jia
name: Longarini, Iacopo
name: Lowette, Steven
name: Lubatti, Henry
name: Lutz, Margaret
name: Luo, Jingyu
name: Mamužić, Judita
name: Marinangeli, Matthieu
name: Mariotti, Alberto
name: Marlow, Daniel
name: McCullough, Matthew
name: McDermott, Kevin
name: Mermod, P.
name: Milstead, David
name: Mitsou, Vasiliki A.
name: Berlingen, Javier Montejo
name: Moortgat, Filip
name: Morandini, Alessandro
name: Morris, Alice Polyxeni
name: Morse, David Michael
name: Mrenna, Stephen
name: Nachman, Benjamin
name: Nemevšek, Miha
name: Nesti, Fabrizio
name: Ohm, Christian
name: Pascoli, Silvia
name: Pedro, Kevin
name: Peña, Cristián
name: Rodriguez, Karla Josefina Pena
name: Piedra, Jónatan
name: Pinfold, James L.
name: Policicchio, Antonio
name: Popara, Goran
name: Prisciandaro, Jessica
name: Proffitt, Mason
name: Rauco, Giorgia
name: Redi, Federico
name: Reece, Matthew
name: Hall, Allison Reinsvold
name: Sfar, H. Rejeb
name: Renner, Sophie
name: Roepe, Amber
name: Ronzani, Manfredi
name: Salvioni, Ennio
name: Santra, Arka
name: Sawada, Ryu
name: Scholtz, Jakub
name: Schuster, Philip
name: Schwaller, Pedro
name: Sebastiani, Cristiano
name: Sekmen, Sezen
name: Selvaggi, Michele
name: Si, Weinan
name: Soffi, Livia
name: Stolarski, Daniel
name: Stuart, David
name: Stupak, John
name: Sung, Kevin
name: Taylor, Wendy
name: Templ, Sebastian
name: Thomas, Brooks
name: Torró-Pastor, Emma
name: Trocino, Daniele
name: Trojanowski, Sebastian
name: Trovato, Marco
name: Tsai, Yuhsin
name: Tully, C. G.
name: Vámi, Tamás Álmos
name: Vasquez, Juan Carlos
name: Sierra, Carlos Vázquez
name: Vellidis, K.
name: Vermassen, Basile
name: Vit, Martina
name: Walker, Devin G. E.
name: Wang, Xiao-Ping
name: Watts, Gordon
name: Xie, Si
name: Yexley, Melissa
name: Young, Charles
name: Yu, Jiang-Hao
name: Zalewski, Piotr
name: Zhang, Yongchao
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at the weak scale. When produced at experiments such as the Large Hadron Collider (LHC) at CERN, these long-lived particles (LLPs) can decay far from the interaction vertex of the primary proton-proton collision. Such LLP signatures are distinct from those of promptly decaying particles that are targeted by the majority of searches for new physics at the LHC, often requiring customized techniques to identify, for example, significantly displaced decay vertices, tracks with atypical properties, and short track segments. Given their non-standard nature, a comprehensive overview of LLP signatures at the LHC is beneficial to ensure that possible avenues of the discovery of new physics are not overlooked. Here we report on the joint work of a community of theorists and experimentalists with the ATLAS, CMS, and LHCb experiments --- as well as those working on dedicated experiments such as MoEDAL, milliQan, MATHUSLA, CODEX-b, and FASER --- to survey the current state of LLP searches at the LHC, and to chart a path for the development of LLP searches into the future, both in the upcoming Run 3 and at the High-Luminosity LHC. The work is organized around the current and future potential capabilities of LHC experiments to generally discover new LLPs, and takes a signature-based approach to surveying classes of models that give rise to LLPs rather than emphasizing any particular theory motivation. We develop a set of simplified models; assess the coverage of current searches; document known, often unexpected backgrounds; explore the capabilities of proposed detector upgrades; provide recommendations for the presentation of search results; and look towards the newest frontiers, namely high-multiplicity "dark showers", highlighting opportunities for expanding the LHC reach for these signals.