373 research outputs found
Search for long lived Heavy Neutral Leptons using a displaced jet tagger in the CMS experiment
No full textAbstract: This thesis presents a search for long-lived heavy neutral leptons (HNLs) using proton-proton collision events, with a focus on the MSM model for HNL production. The MSM model is a theoretical framework that extends the Standard Model of particle physics to include right-handed neutrinos and provides a possible explanation for the observed neutrino masses and mixing angles. We have analyzed a data sample containing two leptons (electron or muon) and jets, with an integrated luminosity of 138 $\mathrm{fb
Prospects for heavy neutral lepton searches at short and medium baseline reactor experiments
No full textAbstract: Heavy neutrinos with masses in the MeV range can in principle simultaneously explain the light neutrino masses and the origin of baryonic matter in the universe. The strongest constraints on their properties come from their potential impact on the formation of light elements in the early universe. Since these constraints rely on assumptions about the cosmic history, independent checks in the laboratory are highly desirable. In this paper, we discuss the opportunity to search for heavy neutrinos within the MeV mass range in short and medium baseline reactor neutrino experiments, using the SoLid, JUNO and TAO experiments as examples. These experiments can give the currently strongest upper bound on the mixing between the light electron neutrinos and the heavy neutrino in the 2-9 MeV mass range
Terrestrial very-long-baseline atom interferometry: summary of the second workshop
No full textThis summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024 (Second Terrestrial Very-Long-Baseline Atom Interferometry Workshop, Imperial College, April 2024), building on the initial discussions during the inaugural workshop held at CERN in March 2023 (First Terrestrial Very-Long-Baseline Atom Interferometry Workshop, CERN, March 2023). Like the summary of the first workshop (Abend et al. in AVS Quantum Sci. 6:024701, 2024), this document records a critical milestone for the international atom interferometry community. It documents our concerted efforts to evaluate progress, address emerging challenges, and refine strategic directions for future large-scale atom interferometry projects. Our commitment to collaboration is manifested by the integration of diverse expertise and the coordination of international resources, all aimed at advancing the frontiers of atom interferometry physics and technology, as set out in a Memorandum of Understanding signed by over 50 institutions (Memorandum of Understanding for the Terrestrial Very Long Baseline Atom Interferometer Study).The workshop was partially funded by contributions from the Long Range Broad Agency Announcement (BAA) for the Navy and Marine Corps Science and Technology programme, Hannover Leibniz University, and the Physics Department at Imperial College London.Article signat per 322 autors/es: Philippos Balamatsias, Antun Balaž, Hannah Banks, Rachel L. Barcklay, Michele Barone, Michele Barsanti, Mark G. Bason, Angelo Bassi, Jean-Baptiste Bayle, Charles F. A. Baynham, Quentin Beaufils, Sélyan Beldjoudi, Aleksandar Belić, Shayne Bennetts, Jose Bernabeu, Andrea Bertoldi, Clara Bigard, N. P. Bigelow, Robert Bingham, Diego Blas, Alexey Bobrick, Samuel Boehringer, Aleksandar Bogojević, Kai Bongs, Daniela Bortoletto, Philippe Bouyer, Christian Brand, Oliver Buchmueller, Gabriela Buica, Sergio Calatroni, Léo Calmels, Priscilla Canizares, Benjamin Canuel, Ana Caramete, Laurentiu-Ioan Caramete, Matteo Carlesso, John Carlton, Samuel P. Carman, Andrew Carroll, Mateo Casariego, Minoas Chairetis, Vassilis Charmandaris, Upasna Chauhan, Jiajun Chen, Maria Luisa Marilù Chiofalo, Donatella Ciampini, Alessia Cimbri, Pierre Cladé, Jonathon Coleman, Florin Lucian Constantin, Carlo R. Contaldi, Robin Corgier, Bineet Dash, G. J. Davies, Claudia de Rham, Albert De Roeck, Daniel Derr, Soumyodeep Dey, Fabio Di Pumpo, Goran S. Djordjevic, Babette Döbrich, Peter Dornan, Michael Doser, Giannis Drougakis, Jacob Dunningham, Alisher Duspayev, Sajan Easo, Joshua Eby, Maxim Efremov, Gedminas Elertas, John Ellis, Nicholas Entin, Stephen Fairhurst, Mattia Fanì, Farida Fassi, Pierre Fayet, Daniel Felea, Jie Feng, Robert Flack, Chris Foot, Tim Freegarde, Elina Fuchs, Naceur Gaaloul, Dongfeng Gao, Susan Gardner, Barry M. Garraway, Carlos L. Garrido Alzar, Alexandre Gauguet, Enno Giese, Patrick Gill, Gian F. Giudice, Eric P. Glasbrenner, Jonah Glick, Peter W. Graham, Eduardo Granados, Paul F. Griffin, Jordan Gué, Saïda Guellati-Khelifa, Subhadeep Gupta, Vishu Gupta, Lucia Hackermueller, Martin Haehnelt, Timo Hakulinen, Klemens Hammerer, Ekim T. Hanımeli, Tiffany Harte, Sabrina Hartmann, Leonie Hawkins, Aurelien Hees, Alexander Herbst, Thomas M. Hird, Richard Hobson, Jason Hogan, Bodil Holst, Michael Holynski, Onur Hosten, Chung Chuan Hsu, Wayne Cheng-Wei Huang, Kenneth M. Hughes, Kamran Hussain, Gert Hütsi, Antonio Iovino, Maria-Catalina Isfan, Gregor Janson, Peter Jeglič, Philippe Jetzer, Yijun Jiang, Gediminas Juzeliūnas, Wilhelm Kaenders, Matti Kalliokoski, Alex Kehagias, Eva Kilian, Carsten Klempt, Peter Knight, Soumen Koley, Bernd Konrad, Tim Kovachy, Markus Krutzik, Mukesh Kumar, Pradeep Kumar, Hamza Labiad, Shau-Yu Lan, Arnaud Landragin, Greg Landsberg, Mehdi Langlois, Bryony Lanigan, Bruno Leone, Christophe Le Poncin-Lafitte, Samuel Lellouch, Marek Lewicki, Yu-Hung Lien, Lucas Lombriser, Elias Lopez Asamar, J. Luis Lopez-Gonzalez, Chen Lu, Giuseppe Gaetano Luciano, Nathan Lundblad, Cristian de J. López Monjaraz, Adam Lowe, Mažena Mackoit-Sinkevičienė, Michele Maggiore, Anirban Majumdar, Konstantinos Makris, Azadeh Maleknejad, Anna L. Marchant, Agnese Mariotti, Christos Markou, Barnaby Matthews, Anupam Mazumdar, Christopher McCabe, Matthias Meister, Giorgio Mentasti, Jonathan Menu, Giuseppe Messineo, Bernd Meyer-Hoppe, Salvatore Micalizio, Federica Migliaccio, Peter Millington, Milan Milosevic, Abhay Mishra, Jeremiah Mitchell, Gavin W. Morley, Noam Mouelle, Jürgen Müller, David Newbold, Wei-Tou Ni, Christian Niehof, Johannes Noller, Senad Odžak, Daniel K. L. Oi, Andreas Oikonomou, Yasser Omar, Chris Overstreet, Vishnupriya Puthiya Veettil, Julia Pahl, Sean Paling, Zhongyin Pan, George Pappas, Vinay Pareek, Elizabeth Pasatembou, Mauro Paternostro, Vishal K. Pathak, Emanuele Pelucchi, Franck Pereira dos Santos, Achim Peters, Annie Pichery, Igor Pikovski, Apostolos Pilaftsis, Florentina-Crenguta Pislan, Robert Plunkett, Rosa Poggiani, Marco Prevedelli, Johann Rafelski, Juhan Raidal, Martti Raidal, Ernst Maria Rasel, Sébastien Renaux-Petel, Pedro Rivero-Antunez, Tangui Rodzinka, Albert Roura, Jan Rudolph, Dylan Sabulsky, Marianna S. Safronova, Mairi Sakellariadou, Leonardo Salvi, Muhammed Sameed, Sumit Sarkar, Patrik Schach, Stefan Alaric Schäffer, Jesse Schelfhout, Manuel Schilling, Vladimir Schkolnik, Wolfgang P. Schleich, Dennis Schlippert, Ulrich Schneider, Florian Schreck, Ariel Schwartzman, Nico Schwersenz, Olga Sergijenko, Haifa Rejeb Sfar, Lijing Shao, Ian Shipsey, Jing Shu, Yeshpal Singh, Carlos F. Sopuerta, Marianna Sorba, Fiodor Sorrentino, Alessandro D. A. M. Spallicci, Petruta Stefanescu, Nikolaos Stergioulas, Daniel Stoerk, Hrudya Thaivalappil Sunilkumar, Jannik Ströhle, Zoie Tam, Dhruv Tandon, Yijun Tang, Dorothee Tell, Jacques Tempere, Dylan J. Temples, Rohit P. Thampy, Ingmari C. Tietje, Guglielmo M. Tino, Jonathan N. Tinsley, Ovidiu Tintareanu Mircea, Kimberly Tkalčec, Andrew J. Tolley, Vincenza Tornatore, Alejandro Torres-Orjuela, Philipp Treutlein, Andrea Trombettoni, Christian Ufrecht, Juan Urrutia, Tristan Valenzuela, Linda R. Valerio, Maurits van der Grinten, Ville Vaskonen, Verónica Vázquez-Aceves, Hardi Veermäe, Flavio Vetrano, Nikolay V. Vitanov, Wolf von Klitzing, Sebastian Wald, Thomas Walker, Reinhold Walser, Jin Wang, Yan Wang, C. A. Weidner, André Wenzlawski, Michael Werner, Lisa Wörner, Mohamed E. Yahia, Efe Yazgan, Emmanuel Zambrini Cruzeiro, M. Zarei, Mingsheng Zhan, Shengnan Zhang, Lin Zhou & ErikPostprint (published version
SoLid: A short baseline reactor neutrino experiment
No full textThe SoLid experiment, short for Search for Oscillations with a Lithium-6 detector, is a new generation neutrino experiment which tries to address the key challenges for high precision reactor neutrino measurements at very short distances from a reactor core and with little or no overburden. The primary goal of the SoLid experiment is to perform a precise measurement of the electron antineutrino energy spectrum and flux and to search for very short distance neutrino oscillations as a probe of eV-scale sterile neutrinos. This paper describes the SoLid detection principle, the mechanical design and the construction of the detector. It then reports on the installation and commissioning on site near the BR2 reactor, Belgium, and finally highlights its performance in terms of detector response and calibration
Study of excited <tex>\Lambda_{b}^{0}</tex> in proton-proton collisions at 1as=13TeV
No full textAbstract: A study of excited Lambda(0)(b) baryons is reported, based on a data sample collected in 2016-2018 with the CMS detector at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of up to 140fb(-1). The existence of four excited Lambda(0)(b) states: Lambda(0)(b) (5912)(0), Lambda(0)(b) (5920)(0), Lambda(0)(b) (6146)(0), and Lambda(0)(b) (6152)(0) in the Lambda(0)(b)pi(+)pi(-) mass spectrum is confirmed, and their masses are measured. The Lambda(0)(b)pi(+)pi(-) mass distribution exhibits a broad excess of events in the region of 6040-6100 MeV, whose origin cannot be discerned with the present data. (C) 2020 The Author(s). Published by Elsevier B.V
Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at <tex>\sqrt{s_{NN}}$</tex>=5.02 TeV
No full textAbstract: Evidence for the light-by-light scattering process, gamma gamma -> gamma gamma, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02 TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390 mu b(-1) recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy E-T(gamma) > 2 GeV, pseudorapidity vertical bar eta(gamma)vertical bar 5 GeV, diphoton transverse momentum p(T)(gamma gamma) gamma gamma) = 120 +/- 46(stat) +/- 28(syst) +/- 12(theo) nb, is consistent with the standard model prediction. The m(gamma gamma) distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the gamma gamma -> a -> gamma gamma process, in the mass range m(a) = 5-90 GeV. (C) 2019 The Author(s). Published by Elsevier B.V
Observation of <tex>B_{s}^{0}</tex> yield ratio in PbPb collisions at 1aS-NN=5.02 TeV
No full textAbstract: The B-s(0) and B+ production yields are measured in PbPb collisions at a center-of-mass energy per nucleon pair of 5.02 TeV. The data sample, collected with the CMS detector at the LHC, corresponds to an integrated luminosity of 1.7 nb(-1). The mesons are reconstructed in the exclusive decay channels B-s(0) -> J/psi (mu(+)mu(-))phi(K+K-) and B+ -> J/psi(mu(+)mu(-))K+ in the transverse momentum range 7-50 GeV/c and absolute rapidity 0-2.4. The B-s(0) meson is observed with a statistical significance in excess of five standard deviations for the first time in nucleus-nucleus collisions. The measurements are performed as functions of the transverse momentum of the B mesons and of the PbPb collision centrality. The ratio of production yields of B-s(0) and B+ is measured and compared to theoretical models that include quark recombination effects. (C) 2022 The Author(s). Published by Elsevier B.V
Search for medium effects using jets from bottom quarks in PbPb collisions at <tex>\sqrt{s_{NN}}$</tex>=5.02 TeV
No full textAbstract: The first study of the shapes of jets arising from bottom (b) quarks in heavy ion collisions is presented. Jet shapes are studied using charged hadron constituents as a function of their radial distance from the jet axis. Lead-lead (PbPb) collision data at a nucleon-nucleon center-of-mass energy of root s(NN)= 5.02 TeV were recorded by the CMS detector at the LHC, with an integrated luminosity of 1.69nb(-1). Compared to proton-proton collisions, aredistribution of the energy inbjets to larger distances from the jet axis is observed in PbPb collisions. This medium-induced redistribution is found to be substantially larger forbjets than for inclusive jets. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3)
Measurement of the B-s(0) \u2192 mu(+)mu(-) decay properties and search for the B-0 \u2192 mu(+)mu(-) decay in proton-proton collisions at 1as=13 TeV
No full textAbstract: Measurements are presented of the B0s & RARR; & mu;+& mu;- branching fraction and effective lifetime, as well as results of a search for the B0 & RARR; & mu;+& mu;- decay in proton-proton collisions at & RADIC;s =13 TeV at the LHC. The analysis is based on data collected with the CMS detector in 2016-2018 corresponding to an integrated luminosity of 140 fb-1. The branching fraction of the B0s & RARR; & mu;+& mu;- decay and the effective B0s meson lifetime are the most precise single measurements to date. No evidence for the B0 & RARR; & mu;+& mu;- decay has been found. All results are found to be consistent with the standard model predictions and previous measurements. & COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons .org /licenses /by /4 .0/). Funded by SCOAP3
Observation of electroweak W+W- pair production in association with two jets in proton-proton collisions at 1as=13 TeV
No full textAbstract: An observation is reported of the electroweak production of a W+W- pair in association with two jets, with both W bosons decaying leptonically. The data sample corresponds to an integrated luminosity of 138 fb(-1) of proton-proton collisions at root s =13 TeV, collected by the CMS detector at the CERN LHC. Events are selected by requiring exactly two opposite-sign leptons (electrons or muons) and two jets with large pseudorapidity separation and high dijet invariant mass. Events are categorized based on the flavor of the final-state leptons. A signal is observed with a significance of 5.6 standard deviations (5.2 expected) with respect to the background-only hypothesis. The measured fiducial cross section is 10.2 +/- 2.0 fb and this value is consistent with the standard model prediction of 9.1 +/- 0.6 fb. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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