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Author Alekhin, S. et al; Hernandez, P.
Title A facility to search for hidden particles at the CERN SPS: the SHiP physics case Type Journal Article
Year 2016 Publication Reports on Progress in Physics Abbreviated Journal Rep. Prog. Phys.
Volume (down) 79 Issue 12 Pages 124201 - 137pp
Keywords beyond the standard model physics; intensity frontier experiment; hidden sectors; heavy neutral leptons; dark photons
Abstract This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, tau -> 3 μand to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the standard model and describe interactions between new particles and four different portals-scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.
Address [Alekhin, Sergey] DESY, Platanenallee 6, D-15738 Zeuthen, Germany, Email: oleg.ruchayskiy@cern.ch
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0034-4885 ISBN Medium
Area Expedition Conference
Notes WOS:000387025400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2852
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Author Abdullahi, A.M. et al; Lopez-Pavon, J.
Title The present and future status of heavy neutral leptons Type Journal Article
Year 2023 Publication Journal of Physics G Abbreviated Journal J. Phys. G
Volume (down) 50 Issue 2 Pages 020501 - 100pp
Keywords Neutrinos; beyond the standard model; sterile neutrinos
Abstract The existence of nonzero neutrino masses points to the likely existence of multiple Standard Model neutral fermions. When such states are heavy enough that they cannot be produced in oscillations, they are referred to as heavy neutral leptons (HNLs). In this white paper, we discuss the present experimental status of HNLs including colliders, beta decay, accelerators, as well as astrophysical and cosmological impacts. We discuss the importance of continuing to search for HNLs, and its potential impact on our understanding of key fundamental questions, and additionally we outline the future prospects for next-generation future experiments or upcoming accelerator run scenarios.
Address [Abdullahi, Asli M.; Plestid, Ryan] Fermilab Natl Accelerator Lab, Theoret Phys Dept, POB 500, Batavia, IL 60510 USA, Email: shoemaker@vt.edu
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000918351600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5486
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Author Alimena, J. et al; Hirsch, M.; Mamuzic, J.; Mitsou, V.A.; Santra, A.
Title Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider Type Journal Article
Year 2020 Publication Journal of Physics G Abbreviated Journal J. Phys. G
Volume (down) 47 Issue 9 Pages 090501 - 226pp
Keywords beyond the Standard Model; long-lived particles; Large Hadron Collider; high-luminosity LHC; collider phenomenology; high-energy collider experiments
Abstract 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.
Address [Alimena, Juliette; Hill, Christopher S.] Ohio State Univ, Dept Phys, 191 W Woodruff Ave, Columbus, OH 43210 USA, Email: juliette.alimena@cern.ch;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000570614200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4535
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Author Cheng, L.; Eberhardt, O.; Murphy, C.W.
Title Novel theoretical constraints for color-octet scalar models Type Journal Article
Year 2019 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume (down) 43 Issue 9 Pages 093101 - 11pp
Keywords beyond the Standard Model; extension of Higgs sector; EW symmetry breaking
Abstract We study the theoretical constraints on a model whose scalar sector contains one color octet and one or two color singlet SU(2)(L) doublets. To ensure unitarity of the theory, we constrain the parameters of the scalar potential for the first time at the next-to-leading order in perturbation theory. Moreover, we derive new conditions guaranteeing the stability of the potential. We employ the HEPfit package to extract viable parameter regions at the electroweak scale and test the stability of the renormalization group evolution up to the multi-TeV region. Furthermore, we set upper limits on the scalar mass splittings. All results are given for both cases with and without a second scalar color singlet.
Address [Cheng, Li] Inst Appl Phys & Computat Math, Beijing 100094, Peoples R China, Email: clmamuphy@sina.cn;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:000482015900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4115
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Author Bordes, J.; Chan, H.M.; Tsou, S.T.
Title delta(CP) for leptons and a new take on CP physics with the FSM Type Journal Article
Year 2021 Publication International Journal of Modern Physics A Abbreviated Journal Int. J. Mod. Phys. A
Volume (down) 36 Issue Pages 2150236 - 22pp
Keywords Phenomenology beyond the Standard Model; framed Standard Model; leptonic CP violation; CP physics
Abstract A bonus of the framed Standard Model (FSM), constructed initially to explain the mass and mixing patterns of quarks and leptons, is a solution (without axions) of the strong CP problem by cancelling the theta-angle term theta(I) Tr(H-mu v H-mu v*) in coloura by a chiral transformation on a quark zero mode which is inherent in FSM, and produces thereby a CP-violating phase in the CKM matrix similar in size to what is observed.' Extending here to flavour, one finds that there are two terms proportional to Tr(G(mu v) G(mu v)*): (a) in the action from flavour instantons with unknown coefficient, say theta(I)', (b) induced by the above FSM solution to the strong CP-problem with therefore known coefficient theta(C)'. Both terms can be cancelled in the FSM by a chiral transformation on the lepton zero mode to give a Jarlskog invariant J' in the PMNS matrix for leptons of order 10(-2), as is hinted by the experiment. But if, as suggested in Ref. 2, the term theta(I)' is to be cancelled by a chiral transformation in the predicted hidden sector to solve the strong CP problem therein, leaving only the term theta(C)' to be cancelled by the chiral transformation on leptons, then the following prediction results: J' similar to -0.012 (delta(CP)'similar to (1.11)pi) which is (i) of the right order, (ii) of the right sign and (iii) in the range favoured by the present experiment. Together with the earlier result for quarks, this offers an attractive unified treatment of all known CP physics.
Address [Bordes, Jose] Univ Valencia, Ctr Mixto CSIC, Dept Fis Teor, Calle Dr Moliner 50, E-46100 Burjassot, Valencia, Spain, Email: jose.m.bordes@uv.es;
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0217-751x ISBN Medium
Area Expedition Conference
Notes WOS:000732963000007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5058
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