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1,057 results on '"Vila, Iván"'

1. The Canfranc Axion Detection Experiment (CADEx): Search for axions at 90 GHz with Kinetic Inductance Detectors

Author

Aja, Beatriz, Cuendis, Sergio Arguedas, Arregui, Ivan, Artal, Eduardo, Barreiro, R. Belén, Casas, Francisco J., de Ory, Maria C., Díaz-Morcillo, Alejandro, de la Fuente, Luisa, Gallego, Juan Daniel, García-Barceló, José María, Gimeno, Benito, Gomez, Alicia, Granados, Daniel, Kavanagh, Bradley J., Laso, Miguel A. G., Lopetegi, Txema, Lozano-Guerrero, Antonio José, Magaz, Maria T., Martín-Pintado, Jesús, Martínez-González, Enrique, Miralda-Escudé, Jordi, Monzó-Cabrera, Juan, Navarro-Madrid, Jose R., Chico, Ana B. Nuñez, Pascual, Juan Pablo, Pelegrin, Jorge, Garay, Carlos Peña, Rodriguez, David, Socuéllamos, Juan M., Teberio, Fernando, Teniente, Jorge, Vielva, Patricio, Vila, Iván, Vilar, Rocío, and Villa, Enrique

Subjects
High Energy Physics - Experiment, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We propose a novel experiment, the Canfranc Axion Detection Experiment (CADEx), to probe dark matter axions with masses in the range 330-460 $\mu$eV, within the W-band (80-110 GHz), an unexplored parameter space in the well-motivated dark matter window of Quantum ChromoDynamics (QCD) axions. The experimental design consists of a microwave resonant cavity haloscope in a high static magnetic field coupled to a highly sensitive detecting system based on Kinetic Inductance Detectors via optimized quasi-optics (horns and mirrors). The experiment is in preparation and will be installed in the dilution refrigerator of the Canfranc Underground Laboratory. Sensitivity forecasts for axion detection with CADEx, together with the potential of the experiment to search for dark photons, are presented., Comment: 23 pages, 10 figures

Published
2022
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2. Results on Proton-Irradiated 3D Pixel Sensors Interconnected to RD53A Readout ASIC

Author

Duarte-Campderros, Jordi, Curras, Esteban, Fernandez, Marcos, Gomez, Gervasio, Garcia, Andrea, Gonzalez, Javier, Silva, Esther, Vila, Ivan, Jaramillo, Richard, Meschini, Marco, Ceccarelli, Rudy, Dinardo, Mauro, Gennai, Simone, Moroni, Luigi, Zuolo, Davide, Demaria, Natale, Monteil, Ennio, Gaioni, Luigi, Messineo, Alberto, Beta, Gian-Franco Dalla, Menicino, Roberto, and Boscardin, Maurizio

Subjects
Physics - Instrumentation and Detectors
Abstract

Test beam results obtained with 3D pixel sensors bump-bonded to the RD53A prototype readout ASIC are reported. Sensors from FBK (Italy) and IMB-CNM (Spain) have been tested before and after proton-irradiation to an equivalent fluence of about $1$ $\times$ $10^{16}$ $\text{n}_{\text{eq}}$ cm$^{-2}$ (1 MeV equivalent neutrons). This is the first time that one single collecting electrode fine pitch 3D sensors are irradiated up to such fluence bump-bonded to a fine pitch ASIC. The preliminary analysis of the collected data shows no degradation on the hit detection efficiencies of the tested sensors after high energy proton irradiation, demonstrating the excellent radiation tolerance of the 3D pixel sensors. Thus, they will be excellent candidates for the extreme radiation environment at the innermost layers of the HL-LHC experiments., Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of Instrumentation, February 18-22, 2019, Vienna, Austria. arXiv admin note: text overlap with arXiv:1903.01963

Published
2019
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3. Confirmation of the spectral excess in DAMIC at SNOLAB with skipper CCDs

Author

European Commission, European Research Council, National Science Foundation (US), Department of Energy (US), Simons Foundation, Agence Nationale de la Recherche (France), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Universidad Nacional Autónoma de México, Consejo Nacional de Ciencia y Tecnología (México), Aguilar-Arevalo, Alexis, Castelló-Mor, N., Cortabitarte Gutiérrez, Juan, Duarte Campderros, J., Lantero Barreda, Agustín, López Virto, A., Vila, Iván, Vilar Cortabitarte, R., DAMIC, DAMIC-M and SENSEI Collaborations, European Commission, European Research Council, National Science Foundation (US), Department of Energy (US), Simons Foundation, Agence Nationale de la Recherche (France), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Universidad Nacional Autónoma de México, Consejo Nacional de Ciencia y Tecnología (México), Aguilar-Arevalo, Alexis, Castelló-Mor, N., Cortabitarte Gutiérrez, Juan, Duarte Campderros, J., Lantero Barreda, Agustín, López Virto, A., Vila, Iván, Vilar Cortabitarte, R., and DAMIC, DAMIC-M and SENSEI Collaborations

Abstract

We present results from a 3.25 kg−day target exposure of two silicon charge-coupled devices (CCDs), each with 24 megapixels and skipper readout, deployed in the DAMIC setup at SNOLAB. With a reduction in pixel readout noise of a factor of 10 relative to the previous detector, we investigate the excess population of low-energy events in the CCD bulk previously observed above expected backgrounds. We address the dominant systematic uncertainty of the previous analysis through a depth fiducialization designed to reject surface backgrounds on the CCDs. The measured bulk ionization spectrum confirms the presence of an excess population of low-energy events in the CCD target with characteristic rate of ∼7 events per kg-day and electron-equivalent energies of ∼80 eV, whose origin remains unknown.

Published
2024

6. Physics at the CLIC e+e- Linear Collider -- Input to the Snowmass process 2013

Author

Abramowicz, Halina, Abusleme, Angel, Afanaciev, Konstatin, Alexander, Gideon, Tehrani, Niloufar Alipour, Alonso, Oscar, Andersen, Kristoffer K., Arfaoui, Samir, Balazs, Csaba, Barklow, Tim, Battaglia, Marco, Benoit, Mathieu, Bilki, Burak, Blaising, Jean-Jacques, Boland, Mark, Boronat, Marça, Jelisavčić, Ivanka Božović, Burrows, Philip, Chefdeville, Maximilien, Contino, Roberto, Dannheim, Dominik, Demarteau, Marcel, Gutierrez, Marco Aurelio Diaz, Diéguez, Angel, Campderros, Jorge Duarte, Eigen, Gerald, Elsener, Konrad, Feldman, Dan, Felzmann, Uli, Firlej, Mirosław, Firu, Elena, Fiutowski, Tomasz, Francis, Kurt, Gaede, Frank, García, Ignacio García, Ghenescu, Veta, Giudice, Gian, Graf, Norman, Grefe, Christian, Grojean, Christophe, Gupta, Rick S., Hauschild, Michael, Holmestad, Helga, Idzik, Marek, Joram, Christian, Kananov, Sergey, Karyotakis, Yannis, Killenberg, Martin, Klempt, Wolfgang, Kraml, Sabine, Krupa, Beata, Kulis, Szymon, Laštovička, Tomáš, LeBlanc, Greg, Levy, Aharon, Levy, Itamar, Linssen, Lucie, Timoce, Angela Lucaci, Lukić, Strahinja, Makarenko, Vladimir, Marshall, John, Martin, Victoria, Mikkelsen, Rune E., Milutinović-Dumbelović, Gordana, Miyamoto, Akiya, Mönig, Klaus, Moortgat-Pick, Gudrid, Moroń, Jakub, Münnich, Astrid, Neagu, Alina, Pandurović, Mila, Pappadopulo, Duccio, Pawlik, Bogdan, Porod, Werner, Poss, Stéphane, Preda, Titi, Rassool, Roger, Rattazzi, Ricardo, Redford, Sophie, Repond, Jose, Riemann, Sabine, Robson, Aidan, Roloff, Philipp, Ros, Eduardo, Rosten, Jonatan, Ruiz-Jimeno, Alberto, Rzehak, Heidi, Sailer, André, Schlatter, Dieter, Schulte, Daniel, Sefkow, Felix, Seidel, Katja, Shumeiko, Nikolai, Sicking, Eva, Simon, Frank, Smith, Jacob, Soldner, Christian, Stapnes, Steinar, Strube, Jan, Suehara, Taikan, Świentek, Krzysztof, Szalay, Marco, Tanabe, Tomohiko, Tesař, Michal, Thamm, Andrea, Thomson, Mark, Garcia, Juan Trenado, Uggerhøj, Ulrik I., van der Kraaij, Erik, Vila, Iván, Vilella, Eva, Villarejo, Miguel Angel, Gonzalez, Marcelo Alonso Vogel, Vos, Marcel, Watson, Nigel, Weerts, Harry, Wells, James D., Weuste, Lars, Wistisen, Tobias N., Wootton, Kent, Xia, Lei, Zawiejski, Leszek, and Zgura, Ion-Sorin

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Accelerator Physics, Physics - Instrumentation and Detectors
Abstract

This paper summarizes the physics potential of the CLIC high-energy e+e- linear collider. It provides input to the Snowmass 2013 process for the energy-frontier working groups on The Higgs Boson (HE1), Precision Study of Electroweak Interactions (HE2), Fully Understanding the Top Quark (HE3), as well as The Path Beyond the Standard Model -- New Particles, Forces, and Dimensions (HE4). It is accompanied by a paper describing the CLIC accelerator study, submitted to the Frontier Capabilities group of the Snowmass process., Comment: Updated the author list, updated Higgs results and small changes in the text of the Higgs section, updated results on composite Higgs bosons, added and updated references. Final submission for the Snowmass proceedings

Published
2013

7. Forward tracking at the next \boldmath{$e^+e^-$} collider Part II: experimental challenges and detector design

Author

Aplin, Steve, Boronat, Marça, Dannheim, Dominik, Duarte, Jordi, Gaede, F., Ruiz-Jimeno, Alberto, Sailer, Andre, Valentan, Manfred, Vila, Ivan, and Vos, Marcel

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

We present the second in a series of studies into the forward tracking system for a future linear $ e^+ e^- $ collider with a center-of-mass energy in the range from 250 GeV to 3 TeV. In this note a number of specific challenges are investigated, that have caused a degradation of the tracking and vertexing performance in the forward region in previous experiments. We perform a quantitative analysis of the dependence of the tracking performance on detector design parameters and identify several ways to mitigate the performance loss for charged particles emitted at shallow angle.

Published
2013
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8. Structural and environmental monitoring of tracker and vertex systems using Fiber Optic Sensors

Author

Moya, David and Vila, Iván

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Fibre optic sensors (FOS) are an established technique for environmental and deformation monitoring in several areas like civil engineering, aerospace, and energy. Their immunity to electromagnetic and magnetic fields and nuclear environments, its small size, multiplexing capability and the possibility to be embedded make them an attractive technology for the structural and environmental monitoring of collider particle physics experiments. Between all the possible Fibre Optic sensors FBGs (Fiber Bragg Grating) seems to be the best solution for HEP applications. The first step was to characterize FBG sensors for it use in High Energy Physics environment. During last two years we have checked the resistance of the Fibre Bragg Grating sensors to radiation. Two irradiation campaigns with protons have been done at CNA (Centro Nacional de Aceleradores). In the near future these sensors are being planned to be used in detectors (the closest one Belle II.). Several work on integration issues in Belle II PXD-SVD, and checking for environmental and deformation monitoring in the detectors inner part has been done., Comment: LCWS11 International Workshop in Future Linear colliders

Published
2012

11. Search for light Higgs bosons from supersymmetric cascade decays in pp collisions at √s=13TeV

Author

SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search is reported for pairs of light Higgs bosons (H1) produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC pp collisions collected with the CMS detector at √s = 13 TeV and corresponding to an integrated luminosity of 138 fb−1 is used. The search targets events where both H1 bosons decay into bb pairs that are reconstructed ¯as large-radius jets using substructure techniques. No evidence is found for an excess of events beyond the background expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal supersymmetric extension of the SM, where a “singlino” of small mass leads to squark and gluino cascade decays that can predominantly end in a highly Lorentz-boosted singlet-like H1 and a singlino-like neutralino of small transverse momentum. Upper limits are set on the product of the squark or gluino pair production cross section and the square of the bb branching ¯fraction of the H1 in a benchmark model containing almost mass-degenerate gluinos and light-flavour squarks. Under the assumption of an SM-like H1 → bb branching fraction, H ¯ 1 bosons with masses in the range 40–120 GeV arising from the decays of squarks or gluinos with a mass of 1200–2500 GeV are excluded at 95% confidence level.

Published
2023

12. Search for a charged Higgs boson decaying into a heavy neutral Higgs boson and a W boson in proton-proton collisions at √s = 13 TeV

Author

Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, European Commission, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, European Commission, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search for a charged Higgs boson H± decaying into a heavy neutral Higgs boson H and a W boson is presented. The analysis targets the H decay into a pair of tau leptons with at least one of them decaying hadronically and with an additional electron or muon present in the event. The search is based on proton-proton collision data recorded by the CMS experiment during 2016–2018 at √s = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. The data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the product of the cross section and branching fraction for an H± in the mass range of 300–700 GeV, assuming an H with a mass of 200 GeV. The observed limits range from 0.085 pb for an H± mass of 300 GeV to 0.019 pb for a mass of 700 GeV. These are the first limits on H± production in the H± → HW±decay channel at the LHC.

Published
2023

13. Performance of the local reconstruction algorithms for the CMS hadron calorimeter with Run 2 data

Author

Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, European Commission, Agencia Estatal de Investigación (España), Principado de Asturias, Ministerio de Ciencia e Innovación (España), Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, European Commission, Agencia Estatal de Investigación (España), Principado de Asturias, Ministerio de Ciencia e Innovación (España), Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

A description is presented of the algorithms used to reconstruct energy deposited in the CMS hadron calorimeter during Run 2 (2015–2018) of the LHC. During Run 2, the characteristic bunch-crossing spacing for proton-proton collisions was 25 ns, which resulted in overlapping signals from adjacent crossings. The energy corresponding to a particular bunch crossing of interest is estimated using the known pulse shapes of energy depositions in the calorimeter, which are measured as functions of both energy and time. A variety of algorithms were developed to mitigate the effects of adjacent bunch crossings on local energy reconstruction in the hadron calorimeter in Run 2, and their performance is compared.

Published
2023

14. Search for medium effects using jets from bottom quarks in PbPb collisions at √sNN=5.02 TeV

Author

SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

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 √sNN = 5.02 TeV were recorded by the CMS detector at the LHC, with an integrated luminosity of 1.69 nb−1. Compared to proton-proton collisions, a redistribution of the energy in b jets to larger distances from the jet axis is observed in PbPb collisions. This medium-induced redistribution is found to be substantially larger for b jets than for inclusive jets.

Published
2023

15. Search for nonresonant Higgs boson pair production in final state with two bottom quarks and two tau leptons in proton-proton collisions at √s=13 TeV

Author

SCOAP, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Principado de Asturias, European Commission, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, SCOAP, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Principado de Asturias, European Commission, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

A search for the nonresonant production of Higgs boson pairs (HH) via gluon-gluon and vector boson fusion processes in final states with two bottom quarks and two tau leptons is presented. The search uses data from proton-proton collisions at a center-of-mass energy of √s = 13 TeV recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb−1. Events in which at least one tau lepton decays hadronically are considered and multiple machine learning techniques are used to identify and extract the signal. The data are found to be consistent, within uncertainties, with the standard model (SM) predictions. Upper limits on the HH production cross section are set to constrain the parameter space for anomalous Higgs boson couplings. The observed (expected) upper limit at 95% confidence level corresponds to 3.3 (5.2) times the SM prediction for the inclusive HH cross section and to 124 (154) times the SM prediction for the vector boson fusion HH cross section. At 95% confidence level, the Higgs field self-coupling is constrained to be within −1.7 and 8.7 times the SM expectation, and the coupling of two Higgs bosons to two vector bosons is constrained to be within −0.4 and 2.6 times the SM expectation.

Published
2023

16. Test beam performance of a CBC3-based mini-module for the Phase-2 CMS Outer Tracker before and after neutron irradiation

Author

Department of Energy (US), European Organization for Nuclear Research, German Research Foundation, Ministerio de Economía y Competitividad (España), Istituto Nazionale di Fisica Nucleare, European Commission, Science and Technology Facilities Council (UK), National Science Foundation (US), Academy of Finland, CMS Tracker collaboration, Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Gómez, Gervasio, González Sánchez, J., Jaramillo, R., Lasaosa, Clara, Moya, David, Piedra, Jonatan, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, López Virto, A., Vizán, J., Department of Energy (US), European Organization for Nuclear Research, German Research Foundation, Ministerio de Economía y Competitividad (España), Istituto Nazionale di Fisica Nucleare, European Commission, Science and Technology Facilities Council (UK), National Science Foundation (US), Academy of Finland, CMS Tracker collaboration, Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Gómez, Gervasio, González Sánchez, J., Jaramillo, R., Lasaosa, Clara, Moya, David, Piedra, Jonatan, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, López Virto, A., and Vizán, J.

Abstract

The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5–7.5×1034 cm-2s-1. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000–4000 fb-1 of proton-proton collisions at a center-of-mass energy of 13–14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, in a test beam experiment, of the first prototype module based on the final version of the CMS Binary Chip front-end ASIC before and after the module was irradiated with neutrons. Results demonstrate that the prototype module satisfies the requirements, providing efficient tracking information, after being irradiated with a total fluence comparable to the one expected through the lifetime of the experiment.

Published
2023

17. Observation of same-sign WW production from double parton scattering in proton-proton collisions at √s = 13 TeV

Author

SCOAP, Science and Technology Facilities Council (UK), Ministerio de Ciencia, Innovación y Universidades (España), National Science Foundation (US), Agencia Estatal de Investigación (España), European Commission, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, SCOAP, Science and Technology Facilities Council (UK), Ministerio de Ciencia, Innovación y Universidades (España), National Science Foundation (US), Agencia Estatal de Investigación (España), European Commission, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

The first observation of the production of W±W± bosons from double parton scattering processes using same-sign electron-muon and dimuon events in proton-proton collisions is reported. The data sample corresponds to an integrated luminosity of 138fb−1 recorded at a center-of-mass energy of 13 TeV using the CMS detector at the CERN LHC. Multivariate discriminants are used to distinguish the signal process from the main backgrounds. A binned maximum likelihood fit is performed to extract the signal cross section. The measured cross section for production of same-sign W bosons decaying leptonically is 80.7±11.2(stat) +9.5−8.6(syst)±12.1(model)fb, whereas the measured fiducial cross section is 6.28±0.81(stat)±0.69(syst)±0.37(model)fb. The observed significance of the signal is 6.2 standard deviations above the background-only hypothesis.

Published
2023

18. Search for narrow resonances in the b-tagged dijet mass spectrum in proton-proton collisions at √s = 13 TeV

Author

SCOAP, European Commission, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), European Research Council, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, SCOAP, European Commission, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), European Research Council, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

A search is performed for narrow resonances decaying to final states of two jets, with at least one jet originating from a b quark, in proton-proton collisions at √s=13TeV. The data set corresponds to an integrated luminosity of 138fb−1 collected with the CMS detector at the LHC. Jets originating from energetic b hadrons are identified through a b-tagging algorithm that utilizes a deep neural network or the presence of a muon inside a jet. The invariant mass spectrum of jet pairs is well described by a smooth parametrization and no evidence for the production of new particles is observed. Upper limits on the production cross section are set for excited b quarks and other resonances decaying to dijet final states containing b quarks. These limits exclude at 95% confidence level models of Z′ bosons with masses from 1.8 TeV to 2.4 TeV and of excited b quarks with masses from 1.8 TeV to 4.0 TeV. This is the most stringent exclusion of excited b quarks to date.

Published
2023

19. Precision measurement of the Z boson invisible width in pp collisions at √s=13 TeV

Author

SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A precise measurement of the invisible width of the Z boson produced in proton-proton collisions at a center-of-mass energy of 13 TeV is presented using data recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 36.3 fb−1. The result is obtained from a simultaneous fit to kinematic distributions for two data samples of Z boson plus jets: one dominated by Z boson decays to invisible particles and the other by Z boson decays to muon and electron pairs. The invisible width is measured to be 523 ± 3 (stat) ± 16 (syst)MeV. This result is the first precise measurement of the invisible width of the Z boson at a hadron collider, and is the single most precise direct measurement to date, competitive with the combined result of the direct measurements from the LEP experiments.

Published
2023

20. Search for CP violating top quark couplings in pp collisions at √s = 13 TeV

Author

SCOAP, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Trevisani, N., Vila, Iván, Vizán, J., SCOAP, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Trevisani, N., Vila, Iván, and Vizán, J.

Abstract

Results are presented from a search for CP violation in top quark pair production, using proton-proton collisions at a center-of-mass energy of 13 TeV. The data used for this analysis consist of final states with two charged leptons collected by the CMS experiment, and correspond to an integrated luminosity of 35.9 fb−1. The search uses two observables, O1 and O3, which are Lorentz scalars. The observable O1 is constructed from the four-momenta of the charged leptons and the reconstructed top quarks, while O3 consists of the four-momenta of the charged leptons and the b quarks originating from the top quarks. Asymmetries in these observables are sensitive to CP violation, and their measurement is used to determine the chromoelectric dipole moment of the top quark. The results are consistent with the expectation from the standard model.

Published
2023

21. Proton reconstruction with the CMS-TOTEM precision proton spectrometer

Author

European Commission, Ministerio de Ciencia e Innovación (España), European Research Council, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, European Commission, Ministerio de Ciencia e Innovación (España), European Research Council, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

The Precision Proton Spectrometer (PPS) of the CMS and TOTEM experiments collected 107.7 fb-1 in proton-proton (pp) collisions at the LHC at 13 TeV (Run 2). This paper describes the key features of the PPS alignment and optics calibrations, the proton reconstruction procedure, as well as the detector efficiency and the performance of the PPS simulation. The reconstruction and simulation are validated using a sample of (semi)exclusive dilepton events. The performance of PPS has proven the feasibility of continuously operating a near-beam proton spectrometer at a high luminosity hadron collider.

Published
2023

22. Search for CP violation using t¯t events in the lepton+jets channel in pp collisions at √s = 13 TeV

Author

European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, Ministerio de Ciencia e Innovación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, Ministerio de Ciencia e Innovación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

Results are presented on a search for CP violation in the production and decay of top quark-antiquark pairs in the lepton+jets channel. The search is based on data from proton-proton collisions at √s = 13 TeV, collected with the CMS detector, corresponding to an integrated luminosity of 138 fb−1. Possible CP violation effects are evaluated by measuring asymmetries in observables constructed from linearly independent four-momentum vectors of the final-state particles. The dimensionless chromoelectric dipole moment of the top quark obtained from the observed asymmetries is measured to be 0.04±0.10 (stat)±0.07(syst), and the asymmetries exhibit no evidence for CP-violating effects, consistent with expectations from the standard model.

Published
2023

23. Search for a massive scalar resonance decaying to a light scalar and a Higgs boson in the four b quarks final state with boosted topology

Author

SCOAP, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Principado de Asturias, Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Principado de Asturias, Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

We search for new massive scalar particles X and Y through the resonant process X → YH → bbb¯ b, ¯ where H is the standard model Higgs boson. Data from CERN LHC proton-proton collisions are used, collected at a centre-of-mass energy of 13 TeV in 2016–2018 and corresponding to an integrated luminosity of 138 fb−1. The search is performed in mass ranges of 0.9–4 TeV for X and 60–600 GeV for Y, where both Y and H are reconstructed as Lorentz-boosted single large-area jets. The results are interpreted in the context of the next-to-minimal supersymmetric standard model and also in an extension of the standard model with two additional singlet scalar fields. The 95% confidence level upper limits for the production cross section vary between 0.1 and 150 fb depending on the X and Y masses, and represent a significant improvement over results from previous searches.

Published
2023

24. Measurement of the top quark mass using a profile likelihood approach with the lepton + jets final states in proton–proton collisions at √s=13TeV

Author

SCOAP, European Commission, National Aeronautics and Space Administration (US), National Science Foundation (US), European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Principado de Asturias, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, SCOAP, European Commission, National Aeronautics and Space Administration (US), National Science Foundation (US), European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Principado de Asturias, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

The mass of the top quark is measured in 36.3 fb−1 of LHC proton–proton collision data collected with the CMS detector at √s = 13 TeV. The measurement uses a sample of top quark pair candidate events containing one isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to four observables per event to extract the top quark mass. The top quark mass is measured to be 171.77 ± 0.37 GeV. This approach significantly improves the precision over previous measurements.

Published
2023

25. Search for new heavy resonances decaying to WW, WZ, ZZ, WH, or ZH boson pairs in the all-jets final state in proton-proton collisions at √s = 13 TeV

Author

SCOAP, European Commission, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, European Commission, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search for new heavy resonances decaying to WW, WZ, ZZ, WH, or ZH boson pairs in the all-jets final state is presented. The analysis is based on proton-proton collision data recorded by the CMS detector in 2016–2018 at a centre-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 138 fb−1. The search is sensitive to resonances with masses between 1.3 and 6 TeV, decaying to bosons that are highly Lorentz-boosted such that each of the bosons forms a single large-radius jet. Machine learning techniques are employed to identify such jets. No significant excess over the estimated standard model background is observed. A maximum local significance of 3.6 standard deviations, corresponding to a global significance of 2.3 standard deviations, is observed at masses of 2.1 and 2.9 TeV. In a heavy vector triplet model, spin-1 Z and W resonances with masses below 4.8 TeV are excluded at the 95% confidence level (CL). These limits are the most stringent to date. In a bulk graviton model, spin-2 gravitons and spin-0 radions with masses below 1.4 and 2.7 TeV, respectively, are excluded at 95% CL. Production of heavy resonances through vector boson fusion is constrained with upper cross section limits at 95% CL as low as 0.1 fb.

Published
2023

26. Search for new physics using effective field theory in 13 TeV pp collision events that contain a top quark pair and a boosted Z or Higgs boson

Author

SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Agencia Estatal de Investigación (España), Principado de Asturias, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Agencia Estatal de Investigación (España), Principado de Asturias, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

A data sample containing top quark pairs (t¯t) produced in association with a Lorentz-boosted Z or Higgs boson is used to search for signs of new physics using effective field theory. The data correspond to an integrated luminosity of 138 fb−1 of proton-proton collisions produced at a center-of-mass energy of 13 TeV at the LHC and collected by the CMS experiment. Selected events contain a single lepton and hadronic jets, including two identified with the decay of bottom quarks, plus an additional large-radius jet with high transverse momentum identified as a Z or Higgs boson decaying to a bottom quark pair. Machine learning techniques are employed to discriminate between t¯tZ or t¯tH events and events from background processes, which are dominated by t¯t þ jets production. No indications of new physics are observed. The signal strengths of boosted t¯tZ and t¯tH production are measured, and upper limits are placed on the t¯tZ and t¯tH differential cross sections as functions of the Z or Higgs boson transverse momentum. The effects of new physics are probed using a framework in which the standard model is considered to be the low-energy effective field theory of a higher energy scale theory. Eight possible dimension-six operators are added to the standard model Lagrangian, and their corresponding coefficients are constrained via fits to the data.

Published
2023

27. Observation of electroweak W+W− pair production in association with two jets in proton-proton collisions at √s = 13 TeV

Author

European Commission, European Research Council, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., European Commission, European Research Council, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

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 √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.

Published
2023

28. First constraints from DAMIC-M on sub-GeV dark-matter particles interacting with electrons

Author

SCOAP, European Commission, European Research Council, National Science Foundation (US), Kavli Foundation, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Department of Energy (US), Agencia Nacional de Promoción Científica y Tecnológica (Argentina), Swiss National Science Foundation, Arnquist, I., Castelló-Mor, N., Cortabitarte Gutiérrez, Juan, Duarte Campderros, J., Lantero Barreda, Agustín, López Virto, A., Vila, Iván, Vilar Cortabitarte, R., DAMIC-M Collaboration, SCOAP, European Commission, European Research Council, National Science Foundation (US), Kavli Foundation, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Department of Energy (US), Agencia Nacional de Promoción Científica y Tecnológica (Argentina), Swiss National Science Foundation, Arnquist, I., Castelló-Mor, N., Cortabitarte Gutiérrez, Juan, Duarte Campderros, J., Lantero Barreda, Agustín, López Virto, A., Vila, Iván, Vilar Cortabitarte, R., and DAMIC-M Collaboration

Abstract

We report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed with an integrated exposure of 85.23 g days, and exploits the subelectron charge resolution and low level of dark current of DAMIC-M charge-coupled devices (CCDs). Dark-matter-induced ionization signals above the detector dark current are searched for in CCD pixels with charge up to 7e−. With this dataset we place limits on dark matter particles of mass between 0.53 and 1000MeV/c2, excluding unexplored regions of parameter space in the mass ranges [1.6,1000]MeV/c2 and [1.5,15.1] MeV/c2 for ultralight and heavy mediator interactions, respectively.

Published
2023

29. Evidence for four-top quark production in proton-proton collisions at √s=13TeV

Author

Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), European Commission, Agencia Estatal de Investigación (España), Principado de Asturias, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), European Commission, Agencia Estatal de Investigación (España), Principado de Asturias, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

The production of four top quarks (ttt¯ t)¯ is studied with LHC proton-proton collision data samples collected by the CMS experiment at a center-of-mass energy of 13 TeV, and corresponding to integrated luminosities of up to 138 fb−1. Events that have no leptons (all-hadronic), one lepton, or two oppositesign leptons (where lepton refers only to prompt electrons or prompt muons) are considered. This is the first ttt¯ t measurement ¯ that includes the all-hadronic final state. The observed significance of the ttt¯ t¯ signal in these final states of 3.9 standard deviations (1.5 expected) provides evidence for ttt¯ t production, ¯with a measured cross section of 36+12−11 fb. Combined with earlier CMS results in other final states, the signal significance is 4.0 standard deviations (3.2 expected). The combination returns an observed cross section of 17 ± 4 (stat) ± 3 (syst) fb, which is consistent with the standard model prediction.

Published
2023

30. CMS pythia 8 colour reconnection tunes based on underlying-event data

Author

Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Principado de Asturias, European Research Council, European Commission, Agencia Estatal de Investigación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Principado de Asturias, European Research Council, European Commission, Agencia Estatal de Investigación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

New sets of parameter tunes for two of the colour reconnection models, quantum chromodynamics-inspired and gluon-move, implemented in the pythia 8 event generator, are obtained based on the default CMS pythia 8 underlying-event tune, CP5. Measurements sensitive to the underlying event performed by the CMS experiment at centre-of-mass energies √s=7 and 13TeV, and by the CDF experiment at 1.96TeV are used to constrain the parameters of colour reconnection models and multiple-parton interactions simultaneously. The new colour reconnection tunes are compared with various measurements at 1.96, 7, 8, and 13TeV including measurements of the underlying-event, strange-particle multiplicities, jet substructure observables, jet shapes, and colour flow in top quark pair (t¯t) events. The new tunes are also used to estimate the uncertainty related to colour reconnection modelling in the top quark mass measurement using the decay products of t¯t events in the semileptonic channel at 13TeV.

Published
2023

31. A search for decays of the Higgs boson to invisible particles in events with a top-antitop quark pair or a vector boson in proton-proton collisions at √s = 13TeV

Author

SCOAP, European Commission, European Research Council, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, European Commission, European Research Council, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at √s = 13 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb−1. The 95% confidence level upper limit set on the branching fraction of the 125 GeV Higgs boson to invisible particles, B(H → inv), is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous B(H → inv) searches carried out at √s = 7, 8, and 13 TeV in complementary production modes. The combined upper limit at 95% confidence level on B(H → inv) is 0.15 (0.08 expected).

Published
2023

32. Azimuthal correlations within exclusive dijets with large momentum transfer in photon-lead collisions

Author

CMS Collaboration, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at √sNN=5.02TeV, corresponding to an integrated luminosity of 0.38 nb−1, collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.

Published
2023

33. Measurement of differential cross sections for the production of a Z boson in association with jets in proton-proton collisions at Formula Presented

Author

SCOAP, European Commission, European Research Council, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), German Research Foundation, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Trevisani, N., Vila, Iván, Vizán, J., CMS Collaboration, SCOAP, European Commission, European Research Council, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), German Research Foundation, Tumasyan, Armen, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Trevisani, N., Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

A measurement is presented of the production of Z bosons that decay into two electrons or muons in association with jets, in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were recorded by the CMS Collaboration at the LHC with an integrated luminosity of 35.9fb-1. The differential cross sections are measured as a function of the transverse momentum (pT) of the Z boson and the transverse momentum and rapidities of the five jets with largest pT. The jet multiplicity distribution is measured for up to eight jets. The hadronic activity in the events is estimated using the scalar sum of the pT of all the jets. All measurements are unfolded to the stable-particle level and compared with predictions from various Monte Carlo event generators, as well as with expectations at leading and next-to-leading orders in perturbative quantum chromodynamics.

Published
2023

34. Search for the Higgs boson decay to a pair of electrons in proton-proton collisions at √s=13TeV

Author

SCOAP, European Organization for Nuclear Research, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, European Organization for Nuclear Research, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Principado de Asturias, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search is presented for the Higgs boson decay to a pair of electrons (e+e−) in proton-proton collisions at √s = 13 TeV. The data set was collected with the CMS experiment at the LHC between 2016 and 2018, corresponding to an integrated luminosity of 138 fb−1. The analysis uses event categories targeting Higgs boson production via gluon fusion and vector boson fusion. The observed upper limit on the Higgs boson branching fraction to an electron pair is 3.0 × 10−4 (3.0 × 10−4 expected) at the 95% confidence level, which is the most stringent limit on this branching fraction to date.

Published
2023

35. First measurement of the forward rapidity gap distribution in pPb collisions at √sNN = 8.16 TeV

Author

SCOAP, European Commission, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Tumasyan, Armen, Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernández Manteca, P. J., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., CMS Collaboration, SCOAP, European Commission, Principado de Asturias, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Tumasyan, Armen, Cabrillo, I. J., Calderon, Alicia, Chazin Quero, B., Duarte Campderros, J., Fernández-García, Marcos, Fernández Manteca, P. J., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ricci-Tam, F., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., and CMS Collaboration

Abstract

For the first time at LHC energies, the forward rapidity gap spectra from proton-lead collisions for both proton and lead dissociation processes are presented. The analysis is performed over 10.4 units of pseudorapidity at a center-of-mass energy per nucleon pair of √sNN=8.16TeV, almost 300 times higher than in previous measurements of diffractive production in proton-nucleus collisions. For lead dissociation processes, which correspond to the pomeron-lead event topology, the epos-lhc generator predictions are a factor of 2 below the data, but the model gives a reasonable description of the rapidity gap spectrum shape. For the pomeron-proton topology, the epos-lhc, qgsjet ii, and hijing predictions are all at least a factor of 5 lower than the data. The latter effect might be explained by a significant contribution of ultraperipheral photoproduction events mimicking the signature of diffractive processes. These data may be of significant help in understanding the high energy limit of quantum chromodynamics and for modeling cosmic ray air showers.

Published
2023

36. Measurement of the differential tt ¯ production cross section as a function of the jet mass and extraction of the top quark mass in hadronic decays of boosted top quarks

Author

Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, European Commission, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, European Commission, Principado de Asturias, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A measurement of the jet mass distribution in hadronic decays of Lorentz-boosted top quarks is presented. The measurement is performed in the lepton + jets channel of top quark pair production (tt) events, where the lepton is an electron or muon. The products of the hadronic top quark decay are reconstructed using a single large-radius jet with transverse momentum greater than 400 GeV. The data were collected with the CMS detector at the LHC in protonproton collisions and correspond to an integrated luminosity of 138 fb−1. The differential tt production cross section as a function of the jet mass is unfolded to the particle level and is used to extract the top quark mass. The jet mass scale is calibrated using the hadronic W boson decay within the large-radius jet. The uncertainties in the modelling of the final state radiation are reduced by studying angular correlations in the jet substructure. These developments lead to a significant increase in precision, and a top quark mass of 173.06 ± 0.84 GeV.

Published
2023

37. Measurement of the tt¯ charge asymmetry in events with highly Lorentz-boosted top quarks in pp collisions at √s = 13TeV

Author

Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Principado de Asturias, European Research Council, Ministerio de Ciencia e Innovación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Principado de Asturias, European Research Council, Ministerio de Ciencia e Innovación (España), SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., García Alonso, A., Gómez, Gervasio, Lasaosa, Clara, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

The measurement of the charge asymmetry in top quark pair events with highly Lorentz-boosted top quarks decaying to a single lepton and jets is presented. The analysis is performed using protonproton collisions at √s = 13 TeV with the CMS detector at the LHC and corresponding to an integrated luminosity of 138 fb−1. The selection is optimized for top quarks produced with large Lorentz boosts, resulting in nonisolated leptons and overlapping jets. The top quark charge asymmetry is measured for events with a tt invariant ¯ mass larger than 750 GeV and corrected for detector and acceptance effects using a binned maximum likelihood fit. The measured top quark charge asymmetry of (0.42+0.64−0.69)% is in good agreement with the standard model prediction at next-to-next-to-leading order in quantum chromodynamic perturbation theory with next-to-leading-order electroweak corrections. The result is also presented for two invariant mass ranges, 750–900 and >900 GeV.

Published
2023

38. First observation of the charge carrier density related gain reduction mechanism in LGADs with the Two Photon Absorption-Transient Current Technique

Author

Pape, Sebastián, Currás, Esteban, Fernández García, Marcos Varela, Moll, Michael, Palomo Pinto, Rogelio, Vila, Iván, Wiehe, Moritz, Quintana, Cristian, Universidad de Sevilla. Departamento de Ingeniería Electrónica, Universidad de Sevilla. TIC192: Ingeniería Electrónica, Horizonte 2020, Ministerio de Educación e Investigación. Alemania, and Agencia Estatal de Investigación. España

Subjects
Two Photon Absorption-Transient Current, Low Gain Avalanche Detector, Gain reduction, Technique, Solid state detectors
Abstract

This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). The Low Gain Avalanche Detector (LGAD) technology is very promising for silicon timing detectors and currently heavily researched. Recent studies show that the gain of LGADs highly depends on the charge carrier density inside the gain layer. To study the charge carrier density related gain reduction, the Two Photon Absorption-Transient Current Technique (TPA-TCT) was employed to obtain information on the drift velocity and electric field of a LGAD for different charge carrier densities. The TPA-TCT uses fs-pulse infrared lasers to provide a three-dimensional resolution to study bulk effects. A compact TPA-TCT setup was developed at CERN and is used to measure current transients against the device depth of a 285μm thick PIN and LGAD, fabricated by IMB-CNM. Methods to extract information about the electric field are employed to verify the charge carrier density related gain reduction. The gain layer of the LGAD is spatially resolved for the first time.

Published
2022

39. Fiber laser system of 1550 nm femtosecond pulses with configurable properties for the two-photon excitation of transient currents in semiconductor detectors

Author

Almagro-Ruiz, Azahara, primary, Pape, Sebastian, additional, Muñoz-Marco, Héctor, additional, Wiehe, Moritz, additional, Currás, Esteban, additional, Fernández-García, Marcos, additional, Moll, Michael, additional, Montero, Raúl, additional, Palomo, Francisco Rogelio, additional, Quintana, Cristian, additional, Vila, Iván, additional, and Pérez-Millán, Pere, additional

Published
2022
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40. The Canfranc Axion Detection Experiment (CADEx): search for axions at 90 GHz with Kinetic Inductance Detectors

Author

Aja, Beatriz, primary, Arguedas Cuendis, Sergio, additional, Arregui, Ivan, additional, Artal, Eduardo, additional, Barreiro, R. Belén, additional, Casas, Francisco J., additional, de Ory, Marina C., additional, Díaz-Morcillo, Alejandro, additional, de la Fuente, Luisa, additional, Gallego, Juan Daniel, additional, García-Barceló, Jose María, additional, Gimeno, Benito, additional, Gomez, Alicia, additional, Granados, Daniel, additional, Kavanagh, Bradley J., additional, Laso, Miguel A.G., additional, Lopetegi, Txema, additional, Lozano-Guerrero, Antonio José, additional, Magaz, Maria T., additional, Martín-Pintado, Jesús, additional, Martínez-González, Enrique, additional, Miralda-Escudé, Jordi, additional, Monzó-Cabrera, Juan, additional, Najarro de la Parra, Francisco, additional, Navarro-Madrid, Jose R., additional, Nuñez Chico, Ana B., additional, Pascual, Juan Pablo, additional, Pelegrin, Jorge, additional, Peña Garay, Carlos, additional, Rodriguez, David, additional, Socuéllamos, Juan M., additional, Teberio, Fernando, additional, Teniente, Jorge, additional, Vielva, Patricio, additional, Vila, Iván, additional, Vilar, Rocío, additional, and Villa, Enrique, additional

Published
2022
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41. Search for flavor-changing neutral current interactions of the top quark and Higgs boson in final states with two photons in proton-proton collisions at √ s = 13 TeV

Author

CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández, M., Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, G., Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., Universidad de Cantabria, and SCOAP

Abstract

CMS collaboration: et al., Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137fb−1. No significant excess above the background prediction is observed. Upper limits on the branching fractions (B) of the top quark decaying to a Higgs boson and an up (u) or charm (c) quark are derived through a binned fit to the diphoton invariant mass spectrum. The observed (expected) 95% confidence level upper limits are found to be 0.019% (0.031%) for B(t→Hu) and 0.073% (0.051%) for B(t→Hc). These are the strictest upper limits yet determined., Funded by SCOAP3.

Published
2022

42. Probing charm quark dynamics via multiparticle correlations in Pb-Pb collisions at √sNN=5.02 TeV

Author

CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández, M., Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, G., Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., Universidad de Cantabria, and SCOAP

Abstract

CMS collaboration: et al., Multiparticle azimuthal correlations of prompt D0 mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of √sNN=5.02 TeV . For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v2) of D0 mesons as a function of event centrality and the D0 transverse momentum. The ratios of the four-particle v2 values to previously measured two-particle cumulant results provide direct experimental access to event-by-event fluctuations of charm quark azimuthal anisotropies. These ratios are also found to be comparable to those of inclusive charged particles in the event. However, hints of deviations are seen in the most central and peripheral collisions. To investigate the origin of flow fluctuations in the charm sector, these measurements are compared to a model implementing fluctuations of charm quark energy loss via collisional or radiative processes in the quark-gluon plasma. These models cannot quantitatively describe the data over the full transverse momentum and centrality ranges, although the calculations with collisional energy loss provide a better description of the data., Funded by SCOAP3.

Published
2022

43. Measurement of the production cross section for Z+b jets in proton-proton collisions at √ s = 13 TeV

Author

CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández, M., Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, G., Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., Universidad de Cantabria, SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, European Commission, Agencia Estatal de Investigación (España), and Principado de Asturias

Abstract

CMS Collaboration: et al., The measurement of the cross section for the production of a Z boson, decaying to dielectrons or dimuons, in association with at least one bottom quark jet is performed with proton-proton collision data at √s=13 TeV. The data sample corresponds to an integrated luminosity of 137 fb−1, collected by the CMS experiment at the LHC during 2016–2018. The integrated cross sections for Z+≥1bjet and Z+≥2bjets are reported for the electron, muon, and combined channels. The fiducial cross sections in the combined channel are 6.52±0.04(stat)±0.40(syst)±0.14(theo)pb for Z+≥1bjet and 0.65±0.03(stat)±0.07(syst)±0.02(theo) pb for Z+≥2b jets. The differential cross section distributions are measured as functions of various kinematic observables that are useful for precision tests of perturbative quantum chromodynamics predictions. The ratios of integrated and differential cross sections for Z+≥2b jets and Z+≥1 b jet processes are also determined. The value of the integrated cross section ratio measured in the combined channel is 0.100±0.005(stat)±0.007(syst)±0.003(theo). All measurements are compared with predictions from various event generators., Funded by SCOAP3., Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contracts No. 675440, No. 724704, No. 752730, No. 758316, No. 765710, 824093, No. 884104, and COST Action No. CA16108 (European Union); the Leventis Foundation; the Alfred P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F. R. S.-FNRS and FWO (Belgium) under the “Excellence of Science—EOS“—be.h Project No. 30820817; the Beijing Municipal Science & Technology Commission, No. Z191100007219010; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Deutsche Forschungsgemeinschaft (DFG), under Germany’s Excellence Strategy—EXC 2121 “Quantum Universe”—390833306, and under Project No. 400140256—GRK2497; the Lendület (“Momentum”) Program and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program ÚNKP, the NKFIA research grants No. 123842, No. 123959, No. 124845, No. 124850, No. 125105, No. 128713, No. 128786, and No. 129058 (Hungary); the Council of Science and Industrial Research, India; the Latvian Council of Science; the Ministry of Science and Higher Education and the National Science Center, contracts Opus 2014/15/B/ST2/03998 and 2015/19/B/ST2/02861 (Poland); the Fundação para a Ciência e a Tecnologia, Grant No. CEECIND/01334/2018 (Portugal); the National Priorities Research Program by Qatar National Research Fund; the Ministry of Science and Higher Education, Projects No. 14.W03.31.0026 and No. FSWW-2020-0008, and the Russian Foundation for Basic Research, Project No. 19-42-703014 (Russia); MCIN/AEI/10.13039/501100011033, ERDF “a way of making Europe”, and the Programa Estatal de Fomento de la Investigación Científica y T´ecnica de Excelencia María de Maeztu, grant No. MDM-2017-0765 and Programa Severo Ochoa del Principado de Asturias (Spain); the Stavros Niarchos Foundation (Greece); the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Kavli Foundation; the Nvidia Corporation; the SuperMicro Corporation; the Welch Foundation, Contract NO. C-1845; and the Weston Havens Foundation (USA).

Published
2022

44. The International Linear Collider: Report to Snow mass 2021

Author

German Research Foundation, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat Valenciana, Consejo Superior de Investigaciones Científicas (España), Japan Society for the Promotion of Science, Department of Energy (US), European Commission, National Research Foundation of Korea, National Science Foundation (US), Istituto Nazionale di Fisica Nucleare, ILC International Development Team, Fernández-García, Marcos, Fullana, Esteban, Fuster, Juan, Irles Quiles, Adrián, Mandal, Sanjoy, Martínez-Rivero, Celso, Miralles, Víctor, Miralles López, Marcos, Moreno Llácer, María, Piedra, Jonatan, Ruiz Jimeno, Alberto, Vila, Iván, Yamamoto, Hitoshi, ILC community, German Research Foundation, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat Valenciana, Consejo Superior de Investigaciones Científicas (España), Japan Society for the Promotion of Science, Department of Energy (US), European Commission, National Research Foundation of Korea, National Science Foundation (US), Istituto Nazionale di Fisica Nucleare, ILC International Development Team, Fernández-García, Marcos, Fullana, Esteban, Fuster, Juan, Irles Quiles, Adrián, Mandal, Sanjoy, Martínez-Rivero, Celso, Miralles, Víctor, Miralles López, Marcos, Moreno Llácer, María, Piedra, Jonatan, Ruiz Jimeno, Alberto, Vila, Iván, Yamamoto, Hitoshi, and ILC community

Abstract

The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This document brings the story of the ILC up to date, emphasizing its strong physics motivation, its readiness for construction, and the opportunity it presents to the US and the global particle physics community.

Published
2022

45. Fiber laser system of 1550 nm femtosecond pulses with configurable properties for the two-photon excitation of transient currents in semiconductor detectors

Author

Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat Valenciana, European Commission, Federal Ministry of Education and Research (Germany), Almagro-Ruiz, Azahara, Pape, Sebastian, Muñoz-Marco, Héctor, Wiehe, Moritz, Currás, Esteban, Fernández-García, Marcos, Moll, Michael, Montero Santos, Raúl, Palomo, Francisco Rogelio, Quintana, Cristian, Vila, Iván, Pérez-Millán, Pere, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat Valenciana, European Commission, Federal Ministry of Education and Research (Germany), Almagro-Ruiz, Azahara, Pape, Sebastian, Muñoz-Marco, Héctor, Wiehe, Moritz, Currás, Esteban, Fernández-García, Marcos, Moll, Michael, Montero Santos, Raúl, Palomo, Francisco Rogelio, Quintana, Cristian, Vila, Iván, and Pérez-Millán, Pere

Abstract

A fiber laser system emitting ultrashort femtosecond pulses at 1550 nm with configurable properties has been developed as an excitation source for the two-photon absorption transient current technique (TPA-TCT). The modules of the system are designed to provide the optical specifications required at the output for localized characterization of semiconductor radiation detectors: variation of pulse energy between 10 nJ and 10pJ , variation of the pulse repetition rate from 8.2 MHz to single shot, and variation of pulse duration between 300 and 600 fs. The validity of the system as an excitation source in the TPA-TCT is demonstrated by measuring spatially resolved excited charge carriers in a silicon detector.

Published
2022

46. Beam test performance of a prototype module with Short Strip ASICs for the CMS HL-LHC tracker upgrade

Author

European Commission, CMS Collaboration, Osherson, Marc, Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Gómez, Gervasio, González Sánchez, J., Jaramillo, R., Lasaosa, Clara, Moya, David, Piedra, Jonatan, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, López Virto, A., Vizán, J., European Commission, CMS Collaboration, Osherson, Marc, Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Gómez, Gervasio, González Sánchez, J., Jaramillo, R., Lasaosa, Clara, Moya, David, Piedra, Jonatan, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, López Virto, A., and Vizán, J.

Abstract

The Short Strip ASIC (SSA) is one of the four front-end chips designed for the upgrade of the CMS Outer Tracker for the High Luminosity LHC. Together with the Macro-Pixel ASIC (MPA) it will instrument modules containing a strip and a macro-pixel sensor stacked on top of each other. The SSA provides both full readout of the strip hit information when triggered, and, together with the MPA, correlated clusters called stubs from the two sensors for use by the CMS Level-1 (L1) trigger system. Results from the first prototype module consisting of a sensor and two SSA chips are presented. The prototype module has been characterized at the Fermilab Test Beam Facility using a 120 GeV proton beam.

Published
2022

47. Search for resonances decaying to three W bosons in proton-proton collisions at √s = 13 TeV

Author

SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search for resonances decaying into a W boson and a radion, where the radion decays into two W bosons, is presented. The data analyzed correspond to an integrated luminosity of 138fb−1 recorded in proton-proton collisions with the CMS detector at √s=13TeV. One isolated charged lepton is required, together with missing transverse momentum and one or two massive large-radius jets, containing the decay products of either two or one W bosons, respectively. No excess over the background estimation is observed. The results are combined with those from a complementary channel with an all-hadronic final state, described in an accompanying paper. Limits are set on parameters of an extended warped extra-dimensional model. These searches are the first of their kind at the LHC.

Published
2022

48. Search for resonances decaying to three W bosons in the hadronic final state in proton-proton collisions at √s = 13 TeV

Author

SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), Principado de Asturias, European Commission, European Research Council, Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), Principado de Asturias, European Commission, European Research Council, Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search for Kaluza-Klein excited vector boson resonances, WKK, decaying in cascade to three W bosons via a scalar radion R, WKK→WR→WWW, in a final state containing two or three massive jets is presented. The search is performed with √s=13TeV proton-proton collision data collected by the CMS experiment at the CERN LHC during 2016–2018, corresponding to an integrated luminosity of 138fb−1. Two final states are simultaneously probed, one where the two W bosons produced by the R decay are reconstructed as separate, large-radius, massive jets, and one where they are merged into a single large-radius jet. The observed data are in agreement with the standard model expectations. Limits are set on the product of the WKK resonance cross section and branching fraction to three W bosons in an extended warped extra-dimensional model and are the first of their kind at the LHC.

Published
2022

49. Search for single production of a vector-like T quark decaying to a top quark and a Z boson in the final state with jets and missing transverse momentum at √s = 13TeV

Author

SCOAP, Agencia Estatal de Investigación (España), Principado de Asturias, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, Agencia Estatal de Investigación (España), Principado de Asturias, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Rodrigo, Teresa, Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

A search is presented for single production of a vector-like T quark with charge 2/3 e, in the decay channel featuring a top quark and a Z boson, with the top quark decaying hadronically and the Z boson decaying to neutrinos. The search uses data collected by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb−1 recorded at the CERN LHC in 2016–2018. The search is sensitive to a T quark mass between 0.6 and 1.8 TeV with decay widths ranging from negligibly small up to 30% of the T quark mass. Reconstruction strategies for the top quark are based on the degree of Lorentz boosting of its final state. At 95% confidence level, the upper limit on the product of the cross section and branching fraction for a T quark of small decay width varies between 15 and 602 fb, depending on its mass. For a T quark with decay widths between 10 and 30% of its mass, this upper limit ranges between 16 and 836 fb. For most of the studied range, the results provide the best limits to date. This is the first search for single T quark production based on the full Run 2 data set of the LHC.

Published
2022

50. Search for resonant production of strongly coupled dark matter in proton-proton collisions at 13 TeV

Author

SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Principado de Asturias, European Research Council, Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, Vizán, J., SCOAP, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Principado de Asturias, European Research Council, Agencia Estatal de Investigación (España), CMS Collaboration, Brochero Cifuentes, J. A., Cabrillo, I. J., Calderon, Alicia, Duarte Campderros, J., Fernández-García, Marcos, Fernandez Madrazo, C., Fernández Manteca, P. J., García Alonso, A., Gómez, Gervasio, Martínez-Rivero, Celso, Martínez Ruiz del Arbol, P., Matorras, Francisco, Matorras-Cuevas, Pablo, Piedra, Jonatan, Prieels, C., Ruiz Jimeno, Alberto, Scodellaro, Luca, Vila, Iván, and Vizán, J.

Abstract

The first collider search for dark matter arising from a strongly coupled hidden sector is presented and uses a data sample corresponding to 138 fb−1, collected with the CMS detector at the CERN LHC, at s√ = 13 TeV. The hidden sector is hypothesized to couple to the standard model (SM) via a heavy leptophobic Z′ mediator produced as a resonance in proton-proton collisions. The mediator decay results in two “semivisible” jets, containing both visible matter and invisible dark matter. The final state therefore includes moderate missing energy aligned with one of the jets, a signature ignored by most dark matter searches. No structure in the dijet transverse mass spectra compatible with the signal is observed. Assuming the Z′ boson has a universal coupling of 0.25 to the SM quarks, an inclusive search, relevant to any model that exhibits this kinematic behavior, excludes mediator masses of 1.5–4.0 TeV at 95% confidence level, depending on the other signal model parameters. To enhance the sensitivity of the search for this particular class of hidden sector models, a boosted decision tree (BDT) is trained using jet substructure variables to distinguish between semivisible jets and SM jets from background processes. When the BDT is employed to identify each jet in the dijet system as semivisible, the mediator mass exclusion increases to 5.1 TeV, for wider ranges of the other signal model parameters. These limits exclude a wide range of strongly coupled hidden sector models for the first time.

Published
2022

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