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Journal articleBertone G, Buchmueller OL, Cole PS, 2023,
Perspectives on fundamental cosmology from Low Earth Orbit and the Moon
, npj Microgravity, Vol: 9The next generation of space-based experiments will go hunting for answers to cosmology’s key open questions which revolve around inflation, dark matter and dark energy. Low earth orbit and lunar missions within the European Space Agency’s Human and Robotic Exploration programme can push our knowledge forward in all of these three fields. A radio interferometer on the Moon, a cold atom interferometer in low earth orbit and a gravitational wave interferometer on the Moon are highlighted as the most fruitful missions to plan and execute in the mid-term.
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Journal articleHall G, Grillo AA, 2023,
ASICs for LHC intermediate tracking detectors
, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol: 1050, ISSN: 0168-9002The tracking detectors proposed for the LHC were unprecedented in their size and operational requirements, especially radiation tolerance and data rates. When they were first envisaged it was uncertain that technologies would be available which would meet the specifications, and considerable R&D was necessary to demonstrate this. In particular, customised electronic integrated circuits were evidently essential, yet they were probably technologically the least certain components. The radiation levels and the readout rates in earlier generations of collider experiments were far below those required for the LHC trackers and the number of LHC readout chips required was much larger. Nevertheless, solutions were eventually found, which continue to function reliably with excellent performance. In many ways, the tracker ASIC developments laid foundations and blazed trails for chips later designed for many other sub-detector systems. The ATLAS and CMS trackers developed different solutions to the LHC challenges, and are representative of other LHC systems. This review focuses on the ASIC developments undertaken by these two experiments to explain the most important innovations, recent progress and future challenges. The term “intermediate tracking detectors” is meant to differentiate from the innermost trackers close to the beam pipe and interaction region. This region is served by pixel detectors, whose development began later than the LHC trackers discussed here.
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Journal articleUchida K, Hall G, 2023,
Studies of the CBC3.1 readout ASIC for CMS 2S-modules
, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol: 1048, ISSN: 0168-9002The CBC3.1 is the final version of the CMS Binary Chip for readout of the outer radial region of the upgraded CMS Tracker at the High-Luminosity LHC. The CBC development was completed with an engineering run in 2018 and two pre-production lots delivered in 2019. Large scale manufacture began in May 2021. Issues were raised when some wafers were tested at low temperature (−30 ∘C) and probing was suspended for investigation. After studies, some additional tests were added to reject affected chips and we show that the impact of the low temperature issues is expected to be very small.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2023,
Observation of triple J/psi meson production in proton-proton collisions
, NATURE PHYSICS, ISSN: 1745-2473 -
Journal articleWass PJ, Sumner TJ, Araújo HM, et al., 2023,
Simulating the charging of isolated free-falling masses from TeV to eV energies: Detailed comparison with LISA Pathfinder results
, Physical Review D, Vol: 107, ISSN: 2470-0010A model is presented that explains the charging rate of the LISA Pathfinder test masses by the interplanetary cosmic ray environment. The model incorporates particle-tracking from TeV to eV energies using a combination of geant4 and a custom low-energy particle generation and tracking code. The electrostatic environment of the test mass is simulated allowing for a comparison of the test-mass charging-rate dependence on local electric fields with observations made in orbit. The model is able to reproduce the observed charging behavior with good accuracy using gold surface properties compatible with literature values. The results of the model confirm that a significant fraction of the net charging current is caused by a population of low-energy (∼eV) electrons produced by electron- and ion-induced kinetic emission from the test mass and surrounding metal surfaces. Assuming a gold work function of 4.2 eV, the unbalanced flow of these electrons to and from the unbiased test mass contributes ∼10% of the overall test mass charging rate. Their contribution to the charging-current shot noise is disproportionately higher, and it adds ∼40% to the overall predicted noise. However, even with this increased noise contribution, the overall charging-current noise is still only 40% of that measured in-orbit, and this remains an unsolved issue.
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Journal articleAalbers J, AbdusSalam SS, Abe K, et al., 2023,
A next-generation liquid xenon observatory for dark matter and neutrino physics
, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, Vol: 50, ISSN: 0954-3899- Author Web Link
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- Citations: 1
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Journal articleTumasyan A, Adam W, Ambrogi F, et al., 2022,
Nuclear modification of Y states in pPb collisions at √sNN = 5.02 TeV
, Physics Letters B, Vol: 835, ISSN: 0370-2693Production cross sections of Υ(1S), Υ(2S), and Υ(3S) states decaying into μ+μ− in proton-lead (pPb) collisions are reported using data collected by the CMS experiment at √sNN = 5.02 TeV. A comparison is made with corresponding cross sections obtained with pp data measured at the same collision energy and scaled by the Pb nucleus mass number. The nuclear modification factor for Υ(1S) is found to be RpPb(Υ(1S)) = 0.806±0.024 (stat)±0.059 (syst). Similar results for the excited states indicate a sequentialsuppression pattern, such that RpPb(Υ(1S)) > RpPb(Υ(2S)) > RpPb(Υ(3S)). The suppression of all states is much less pronounced in pPb than in PbPb collisions, and independent of transverse momentum pΥT and center-of-mass rapidity yΥCM of the individual Υ state in the studied range pΥT < 30 GeV/c and |yΥCM| <1.93. Models that incorporate final-state effects of bottomonia in pPb collisions are in better agreement with the data than those which only assume initial-state modifications.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Search for new particles in an extended Higgs sector with four b quarks in the final state at s=13TeV
, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol: 835, ISSN: 0370-2693A search for a massive resonance X decaying to a pair of spin-0 bosons ϕ that themselves decay to pairs of bottom quarks, is presented. The analysis is restricted to the mass ranges mϕ from 25 to 100 GeV and mX from 1 to 3 TeV. For these mass ranges, the decay products of each ϕ boson are expected to merge into a single large-radius jet. Jet substructure and flavor identification techniques are used to identify these jets. The search is based on CERN LHC proton-proton collision data at s=13TeV, collected with the CMS detector in 2016–2018, corresponding to an integrated luminosity of 138fb−1. Model-specific limits, where the two new particles arise from an extended Higgs sector, are set on the product of the production cross section and branching fraction for X→ϕϕ→(bb‾)(bb‾) as a function of the resonances' masses, where both the X→ϕϕ and ϕ→bb‾ branching fractions are assumed to be 100%. These limits are the first of their kind on this process, ranging between 30 and 1 fb at 95% confidence level for the considered mass ranges.
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Journal articleAlonso I, Alpigiani C, Altschul B, et al., 2022,
Cold atoms in space: community workshop summary and proposed road-map
, EPJ QUANTUM TECHNOLOGY, Vol: 9, ISSN: 2662-4400 -
Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Search for new particles in an extended Higgs sector with four b quarks in the final state at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msqrt><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msqrt><mml:mo linebreak="goodbreak" linebreakstyle="after">=</mml:mo><mml:mn>13</mml:mn><mml:mrow><mml:mspace width="0.20em" /><mml:mtext>TeV</mml:mtext></mml:mrow></mml:math>
, Physics Letters B, Vol: 835, Pages: 137566-137566, ISSN: 0370-2693 -
Journal articleApple SM, Kenyon SP, Barke S, et al., 2022,
Measurement of stray electric fields in a capacitive inertial sensor using contactless test-mass charge modulation
, Physical Review D, Vol: 106, ISSN: 2470-0010We present a new technique for measuring the stray electric field in precision space inertial sensors by modulating the electric charge of a free-falling test mass and measuring the resulting coherent Coulomb force. The free charge of the test mass is controlled by ultraviolet photoemission using a pulsed light source synchronized with an oscillating potential capacitively induced on the test mass. We can modulate the test mass charge sinusoidally at an arbitrarily chosen frequency by varying the phase of the UV light pulses relative to the induced test mass potential at the appropriate rate. This technique allows us to optimize the precision of the measurement by choosing a modulation frequency that is within the most sensitive band of the sensor. We present an experimental validation of this approach using an inertial sensor integrated with a torsion pendulum, measuring the equivalent stray potential of the sensor with milliVolt precision in 104 s. We discuss the applicability of this technique for the upcoming Laser Interferometer Space Antenna (LISA) gravitational-wave observatory.
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Journal articleBogomilov M, Tsenov R, Vankova-Kirilova G, et al., 2022,
Multiple Coulomb scattering of muons in lithium hydride
, PHYSICAL REVIEW D, Vol: 106, ISSN: 2470-0010 -
Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Evidence for WW/WZ vector boson scattering in the decay channelνqq produced in association with two jets in proton-proton collisionsat √s = 13 TeV
, Physics Letters B, Vol: 834, Pages: 1-28, ISSN: 0370-2693Evidence is reported for electroweak (EW) vector boson scattering in the decay channel νqq of twoweak vector bosons WV (V = W or Z), produced in association with two parton jets. The search usesa data set of proton-proton collisions at 13 TeV collected with the CMS detector during 2016–2018with an integrated luminosity of 138 fb−1. Events are selected requiring one lepton (electron or muon),moderate missing transverse momentum, two jets with a large pseudorapidity separation and a large dijetinvariant mass, and a signature consistent with the hadronic decay of a W/Z boson. The cross section iscomputed in a fiducial phase space defined at parton level requiring all parton transverse momentapT > 10 GeV and at least one pair of outgoing partons with invariant mass mqq > 100 GeV. The measuredand expected EW WV production cross sections are 1.90+0.53−0.46 pb and 2.23+0.08−0.11(scale) ± 0.05(PDF) pb,respectively, where PDF is the parton distribution function. The observed EW signal strength is μEW =0.85 ± 0.12 (stat)+0.19−0.17 (syst), corresponding to a signal significance of 4.4 standard deviations with 5.1expected, and it is measured keeping the quantum chromodynamics (QCD) associated diboson productionfixed to the standard model prediction. This is the first evidence of vector boson scattering in the νqqdecay channel at LHC. The simultaneous measurement of the EW and QCD associated diboson productionagrees with the standard model prediction.
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Journal articleAkerib DS, Alsum S, Araujo HM, et al., 2022,
Fast and flexible analysis of direct dark matter search data with machine learning
, PHYSICAL REVIEW D, Vol: 106, ISSN: 2470-0010 -
Journal articleTouboul P, Metris G, Rodrigues M, et al., 2022,
Result of the MICROSCOPE weak equivalence principle test
, CLASSICAL AND QUANTUM GRAVITY, Vol: 39, ISSN: 0264-9381- Author Web Link
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- Citations: 8
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Measurement of the Higgs boson width and evidence of its off-shell contributions to ZZ production
, Nature Physics, Vol: 18, Pages: 1329-1334, ISSN: 1745-2473Since the discovery of the Higgs boson in 2012, detailed studies of its properties have been ongoing. Besides its mass, its width—related to its lifetime—is an important parameter. One way to determine this quantity is to measure its off-shell production, where the Higgs boson mass is far away from its nominal value, and relating it to its on-shell production, where the mass is close to the nominal value. Here we report evidence for such off-shell contributions to the production cross-section of two Z bosons with data from the CMS experiment at the CERN Large Hadron Collider. We constrain the total rate of the off-shell Higgs boson contribution beyond the Z boson pair production threshold, relative to its standard model expectation, to the interval [0.0061, 2.0] at the 95% confidence level. The scenario with no off-shell contribution is excluded at a p-value of 0.0003 (3.6 standard deviations). We measure the width of the Higgs boson as ΓH=3.2+2.4−1.7MeV, in agreement with the standard model expectation of 4.1 MeV. In addition, we set constraints on anomalous Higgs boson couplings to W and Z boson pairs.
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Journal articleAbud AA, Abi B, Acciarri R, et al., 2022,
Separation of track- and shower-like energy deposits in ProtoDUNE-SP using a convolutional neural network
, European Physical Journal C: Particles and Fields, Vol: 82, Pages: 1-19, ISSN: 1124-1861Liquid argon time projection chamber detector technology provides high spatial and calorimetric resolutions on the charged particles traversing liquid argon. As a result, the technology has been used in a number of recent neutrino experiments, and is the technology of choice for the Deep Underground Neutrino Experiment (DUNE). In order to perform high precision measurements of neutrinos in the detector, final state particles need to be effectively identified, and their energy accurately reconstructed. This article proposes an algorithm based on a convolutional neural network to perform the classification of energy deposits and reconstructed particles as track-like or arising from electromagnetic cascades. Results from testing the algorithm on experimental data from ProtoDUNE-SP, a prototype of the DUNE far detector, are presented. The network identifies track- and shower-like particles, as well as Michel electrons, with high efficiency. The performance of the algorithm is consistent between experimental data and simulation.
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Journal articleMatsumoto R, Abe K, Hayato Y, et al., 2022,
Search for proton decay via p -> mu(+) K-0 in 0.37 megaton-years exposure of Super-Kamiokande
, PHYSICAL REVIEW D, Vol: 106, ISSN: 2470-0010 -
Journal articleArmano M, Audley H, Baird J, et al., 2022,
Sensor noise in LISA Pathfinder: An extensive in-flight review of the angular and longitudinal interferometric measurement system
, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 106, Pages: 1-34, ISSN: 1550-2368In a previous article [1], we have reported on the first subpicometer interferometer flown in space as part of ESA’s LISA Pathfinder mission, and have shown the residual sensor noise to be on the level of 32.0+2.4−1.7 fm/√Hz. This review provides a deeper and more complete overview of the full system and its interferometric mission performance under varying operational conditions, allowing a much more detailed view on the noise model. We also include the optical measurements of rotations through differential wave front sensing (DWS), which reached a sensitivity of as good as 100 prad/√Hz. We present more evidence for the long-term stability of the interferometric performance and components. This proves a solid foundation for future interferometry in space such as the LISA mission.
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Journal articleAbe K, Akhlaq N, Akutsu R, et al., 2022,
Scintillator ageing of the T2K near detectors fro 2010 to 2021
, JOURNAL OF INSTRUMENTATION, Vol: 17, ISSN: 1748-0221 -
Journal articleTouboul P, Métris G, Rodrigues M, et al., 2022,
MICROSCOPE mission: final results of the test of the equivalence principle
, Physical Review Letters, Vol: 129, ISSN: 0031-9007The MICROSCOPE mission was designed to test the weak equivalence principle (WEP), stating the equality between the inertial and the gravitational masses, with a precision of 10^{-15} in terms of the Eötvös ratio η. Its experimental test consisted of comparing the accelerations undergone by two collocated test masses of different compositions as they orbited the Earth, by measuring the electrostatic forces required to keep them in equilibrium. This was done with ultrasensitive differential electrostatic accelerometers onboard a drag-free satellite. The mission lasted two and a half years, cumulating five months worth of science free-fall data, two-thirds with a pair of test masses of different compositions-titanium and platinum alloys-and the last third with a reference pair of test masses of the same composition-platinum. We summarize the data analysis, with an emphasis on the characterization of the systematic uncertainties due to thermal instabilities and on the correction of short-lived events which could mimic a WEP violation signal. We found no violation of the WEP, with the Eötvös parameter of the titanium and platinum pair constrained to η(Ti,Pt)=[-1.5±2.3(stat)±1.5(syst)]×10^{-15} at 1σ in statistical errors.
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Journal articleArmano M, Audley H, Baird J, et al., 2022,
Transient acceleration events in LISA Pathfinder data: Properties and possible physical origin
, Physical Review D, Vol: 106, ISSN: 2470-0010We present an in depth analysis of the transient events, or glitches, detected at a rate of about one per day in the differential acceleration data of LISA Pathfinder. We show that these glitches fall in two rather distinct categories: fast transients in the interferometric motion readout on one side, and true force transient events on the other. The former are fast and rare in ordinary conditions. The second may last from seconds to hours and constitute the majority of the glitches. We present an analysis of the physical and statistical properties of both categories, including a cross-analysis with other time series like magnetic fields, temperature, and other dynamical variables. Based on these analyses we discuss the possible sources of the force glitches and identify the most likely, among which the outgassing environment surrounding the test-masses stands out. We discuss the impact of these findings on the LISA design and operation, and some risk mitigation measures, including experimental studies that may be conducted on the ground, aimed at clarifying some of the questions left open by our analysis.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
earch for a W′ boson decaying to a vector-like quark and a top or bottom quark in the all-jets final state at s√ = 13 TeV
, The Journal of High Energy Physics, Vol: 2022, Pages: 1-46, ISSN: 1029-8479A search is presented for a heavy W′ boson resonance decaying to a B or T vector-like quark and a t or a b quark, respectively. The analysis is performed using proton-proton collisions collected with the CMS detector at the LHC. The data correspond to an integrated luminosity of 138 fb−1 at a center-of-mass energy of 13 TeV. Both decay channels result in a signature with a t quark, a Higgs or Z boson, and a b quark, each produced with a significant Lorentz boost. The all-hadronic decays of the Higgs or Z boson and of the t quark are selected using jet substructure techniques to reduce standard model backgrounds, resulting in a distinct three-jet W′ boson decay signature. No significant deviation in data with respect to the standard model background prediction is observed. Upper limits are set at 95% confidence level on the product of the W′ boson cross section and the final state branching fraction. A W′ boson with a mass below 3.1 TeV is excluded, given the benchmark model assumption of democratic branching fractions. In addition, limits are set based on generalizations of these assumptions. These are the most sensitive limits to date for this final state.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Search for a W' boson decaying to a vector-like quark and a top or bottom quark in the all-jets final state at root s=13 TeV
, The Journal of High Energy Physics, Vol: 2022, Pages: 1-46, ISSN: 1029-8479A search is presented for a heavy W′ boson resonance decaying to a B or T vector-like quark and a t or a b quark, respectively. The analysis is performed using proton-proton collisions collected with the CMS detector at the LHC. The data correspond to an integrated luminosity of 138 fb−1 at a center-of-mass energy of 13 TeV. Both decay channels result in a signature with a t quark, a Higgs or Z boson, and a b quark, each produced with a significant Lorentz boost. The all-hadronic decays of the Higgs or Z boson and of the t quark are selected using jet substructure techniques to reduce standard model backgrounds, resulting in a distinct three-jet W′ boson decay signature. No significant deviation in data with respect to the standard model background prediction is observed. Upper limits are set at 95% confidence level on the product of the W′ boson cross section and the final state branching fraction. A W′ boson with a mass below 3.1 TeV is excluded, given the benchmark model assumption of democratic branching fractions. In addition, limits are set based on generalizations of these assumptions. These are the most sensitive limits to date for this final state.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Search for high-mass resonances decaying to a jet and aLorentz-boosted resonance in proton-proton collisions at √s = 13 TeV
, Physics Letters B, Vol: 832, Pages: 1-24, ISSN: 0370-2693A search is reported for high-mass hadronic resonances that decay to a parton and a Lorentz-boosted resonance, which in turn decays into a pair of partons. The search is based on data collected with the CMS detector at the LHC in proton-proton collisions at , corresponding to an integrated luminosity of 138. The boosted resonance is reconstructed as a single wide jet with substructure consistent with a two-body decay. The high-mass resonance is thus considered as a dijet system. The jet substructure information and the kinematic properties of cascade resonance decays are exploited to disentangle the signal from the large quantum chromodynamics multijet background. The dijet mass spectrum is analyzed for the presence of new high-mass resonances, and is found to be consistent with the standard model background predictions. Results are interpreted in a warped extra dimension model where the high-mass resonance is a Kaluza–Klein gluon, the boosted resonance is a radion, and the final state partons are all gluons. Limits on the production cross section are set as a function of the Kaluza–Klein gluon and radion masses. These limits exclude at 95% confidence level models with Kaluza–Klein gluon masses in the range 2.0 to 4.3 TeV and radion masses in the range 0.20 to 0.74 TeV. By exploring a novel experimental signature, the observed limits on the Kaluza–Klein gluon mass are extended by up to about 1 TeV compared to previous searches.
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Journal articleAaij R, Abdelmotteleb ASW, Abellán Beteta C, et al., 2022,
First Measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>Z</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mrow><mml:mi>μ</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>μ</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math> Angular Coefficients in the Forward Region of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi><mml:mi>p</mml:mi></mml:math> Collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msqrt><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:mrow></mml:math>
, Physical Review Letters, Vol: 129, ISSN: 0031-9007 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2022,
First Measurement of the Z -> mu(+) mu(-) Angular Coefficients in the Forward Region of pp Collisions at root s=13 TeV
, PHYSICAL REVIEW LETTERS, Vol: 129, ISSN: 0031-9007 -
Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Search for Higgs boson pair production in the four b quark final state in proton-proton collisions at sqrt[s]=13 TeV
, Physical Review Letters, Vol: 129, ISSN: 0031-9007A search for pairs of Higgs bosons produced via gluon and vector boson fusion is presented, focusing on the four b quark final state. The data sample consists of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, and corresponds to an integrated luminosity of 138 fb^{-1}. No deviation from the background-only hypothesis is observed. A 95% confidence level upper limit on the Higgs boson pair production cross section is observed at 3.9 times the standard model prediction for an expected value of 7.8. Constraints are also set on the modifiers of the Higgs field self-coupling, κ_{λ}, and of the coupling of two Higgs bosons to two vector bosons, κ_{2 V}. The observed (expected) allowed intervals at the 95% confidence level are -2.3<κ_{λ}<9.4 (-5.0<κ_{λ}<12.0) and -0.1<κ_{2 V}<2.2 (-0.4<κ_{2 V}<2.5). These are the most stringent observed constraints to date on the HH production cross section and on the κ_{2 V } coupling.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Strategies and performance of the CMS silicon tracker alignment during LHC Run 2
, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment, Vol: 1037, ISSN: 0168-9002The strategies for and the performance of the CMS silicon tracking system alignment during the 2015–2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2022,
Measurement of the Drell-Yan forward-backward asymmetry at high dilepton masses in proton-proton collisions at root s=13 TeV
, The Journal of High Energy Physics, Vol: 2022, Pages: 1-58, ISSN: 1029-8479A measurement of the forward-backward asymmetry of pairs of oppositely charged leptons (dimuons and dielectrons) produced by the Drell-Yan process in proton-proton collisions is presented. The data sample corresponds to an integrated luminosity of 138 fb−1 collected with the CMS detector at the LHC at a center-of-mass energy of 13 TeV. The asymmetry is measured as a function of lepton pair mass for masses larger than 170 GeV and compared with standard model predictions. An inclusive measurement across both channels and the full mass range yields an asymmetry of 0.612 ± 0.005 (stat) ± 0.007 (syst). As a test of lepton flavor universality, the difference between the dimuon and dielectron asymmetries is measured as well. No statistically significant deviations from standard model predictions are observed. The measurements are used to set limits on the presence of additional gauge bosons. For a Z′ boson in the sequential standard model the observed (expected) 95% confidence level lower limit on the Z′ mass is 4.4 TeV (3.7 TeV).
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