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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2025,
Measurement of inclusive and differential cross sections for W<sup>+</sup>W<sup>−</sup> production in proton-proton collisions at s=13.6 TeV
, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol: 861, ISSN: 0370-2693Measurements at s=13.6TeV of the opposite-sign W boson pair production cross section in proton-proton collisions are presented. The data used in this study were collected with the CMS detector at the CERN LHC in 2022, and correspond to an integrated luminosity of 34.8fb−1. Events are selected by requiring one electron and one muon of opposite charge. A maximum likelihood fit is performed on signal- and background-enriched data categories defined by the flavor and charge of the leptons, the number of jets, and number of jets originating from b quarks. The overall sensitivity is significantly better than that of previous results with a similar integrated luminosity. The improvement comes from a more refined control of experimental uncertainties and an improved fit strategy. An inclusive W+W− production cross section of 125.7±5.6 pb is measured, in agreement with standard model predictions. Cross sections are also reported in a fiducial region close to that of the detector acceptance, both inclusively and differentially, as a function of the jet multiplicity in the event. For the first time in proton-proton collisions, WW events with zero, one, and at least two jets are studied simultaneously and compared with recent theoretical predictions.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2025,
Girth and groomed radius of jets recoiling against isolated photons in lead-lead and proton-proton collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msqrt><mml:mrow><mml:msub><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mrow/><mml:mrow><mml:mi mathvariant="normal">NN</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:mrow></mml:msqrt><mml:mo linebreak="goodbreak" linebreakstyle="after">=</mml:mo><mml:mn>5.02</mml:mn><mml:mtext> TeV</mml:mtext></mml:math>
, Physics Letters B, Vol: 861, Pages: 139088-139088, ISSN: 0370-2693 -
Journal articleAalbers J, Akerib DS, Al Musalhi AK, et al., 2025,
Two-neutrino double electron capture of <sup>124</sup>Xe in the first LUX-ZEPLIN exposure
, Journal of Physics G: Nuclear and Particle Physics, Vol: 52, Pages: 015103-015103, ISSN: 0954-3899<jats:title>Abstract</jats:title> <jats:p>The broad physics reach of the LUX-ZEPLIN (LZ) experiment covers rare phenomena beyond the direct detection of dark matter. We report precise measurements of the extremely rare decay of <jats:sup>124</jats:sup>Xe through the process of two-neutrino double electron capture, utilizing a 1.39 kg × yr isotopic exposure from the first LZ science run. A half-life of <jats:inline-formula> <jats:tex-math></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mi>T</mml:mi> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>ν</mml:mi> <mml:mn>2</mml:mn> <mml:mi>EC</mml:mi> </mml:mrow> </mml:msubsup> <mml:mspace width="0.25em"/> <mml:mo>=</mml:mo> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1.09</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.1</mml:mn> <mml:msub> <mml:mn>4</mml:mn> <mml:mrow> <mml:mspace width="0.1em&
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Journal articleAbe K, Abe S, Bronner C, et al., 2025,
First Joint Oscillation Analysis of Super-Kamiokande Atmospheric and T2K Accelerator Neutrino Data
, Physical Review Letters, Vol: 134, ISSN: 0031-9007The Super-Kamiokande and T2K Collaborations present a joint measurement of neutrino oscillation parameters from their atmospheric and beam neutrino data. It uses a common interaction model for events overlapping in neutrino energy and correlated detector systematic uncertainties between the two datasets, which are found to be compatible. Using 3244.4 days of atmospheric data and a beam exposure of 19.7(16.3)×1020 protons on target in (anti)neutrino mode, the analysis finds a 1.9σ exclusion of CP conservation (defined as JCP=0) and a 1.2σ exclusion of the inverted mass ordering.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2025,
Measurement of the double-differential inclusive jet cross section in proton-proton collisions at $$ \sqrt{s} $$ = 5.02 TeV
, Journal of High Energy Physics, Vol: 2025<jats:title>A<jats:sc>bstract</jats:sc> </jats:title> <jats:p>The inclusive jet cross section is measured as a function of jet transverse momentum <jats:italic>p</jats:italic> <jats:sub>T</jats:sub> and rapidity <jats:italic>y</jats:italic>. The measurement is performed using proton-proton collision data at <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> </jats:alternatives> </jats:inline-formula> = 5<jats:italic>.</jats:italic>02 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 27.4 pb<jats:sup> <jats:italic>−</jats:italic>1</jats:sup>. The jets are reconstructed with the anti-<jats:italic>k</jats:italic> <jats:sub>T</jats:sub> algorithm using a distance parameter of <jats:italic>R</jats:italic> = 0<jats:italic>.</jats:italic>4, within the rapidity interval <jats:italic>|y| <</jats:italic> 2, and across the kinematic range 0<jats:italic>.</jats:italic>06 <jats:italic>< p</jats:italic> <jats:sub>T</jats:sub> <jats:italic><</jats:italic> 1 TeV. The jet cross section is unfolded from detector to particle level using the determined jet response and resolution. The results are compared to predictions of perturbative quantum chromodynamics, calculated at both next-to-leading order and next-to-next-to-leading order. The predictions are corrected for nonpertur
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Journal articleKarikar A, Das K, Das I, 2025,
Magnetoresistive and magnetocaloric properties of polycrystalline Sm<inf>0.50</inf>Sr<inf>0.50</inf>MnO<inf>3</inf> compound with short range magnetic ordering
, Journal of Materials Science: Materials in Electronics, Vol: 36, ISSN: 0957-4522In this study, the magnetic and magneto-transport properties of polycrystalline Sm0.50Sr0.50MnO3 have been investigated. The presence of short-range magnetic order plays a crucial role in influencing electron transport, making it a promising pathway for tuning magnetoresistive properties for specific applications. This research focuses on the effects of magnetic nanoclusters on spin-dependent scattering and their impact on magneto-transport and magnetocaloric properties in polycrystalline Sm0.50Sr0.50MnO3. Experimental results reveal a significant magnetocaloric effect and notable magnetoresistance within the liquid nitrogen temperature range. At 100 K, the magnetoresistance reaches approximately 70% under an external magnetic field of 20 kOe. The magnetocaloric entropy change is calculated to be 3.5 J/kg-K for a 70 kOe magnetic field, with the entropy change curve exhibiting a broadened peak, leading to a substantial Relative Cooling Power (RCP). These findings enhance our understanding of the material’s behavior and highlight its potential for various technological applications.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2025,
Study of WH production through vector boson scattering and extraction of the relative sign of the W and Z couplings to the Higgs boson in proton-proton collisions at s=13TeV
, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol: 860, ISSN: 0370-2693A search for the production of a W boson and a Higgs boson through vector boson scattering (VBS) is presented, using CMS data from proton-proton collisions at s=13TeV collected from 2016 to 2018. The integrated luminosity of the data sample is 138fb−1. Selected events must be consistent with the presence of two jets originating from VBS, the leptonic decay of the W boson to an electron or muon, possibly also through an intermediate τ lepton, and a Higgs boson decaying into a pair of b quarks, reconstructed as either a single merged jet or two resolved jets. A measurement of the process as predicted by the standard model (SM) is performed alongside a study of beyond-the-SM (BSM) scenarios. The SM analysis sets an observed (expected) 95% confidence level upper limit of 14.3 (9.9) on the ratio of the measured VBS WH cross section to that expected by the SM. The BSM analysis, conducted within the so-called κ framework, excludes all scenarios with λWZ<0 that are consistent with current measurements, where λWZ=κW/κZ and κW and κZ are the HWW and HZZ coupling modifiers, respectively. The significance of the exclusion is beyond 5 standard deviations, and it is consistent with the SM expectation of λWZ=1.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2025,
Search for a standard model-like Higgs boson in the mass range between 70 and 110 GeV in the diphoton final state in proton-proton collisions at s=13TeV
, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol: 860, ISSN: 0370-2693The results of a search for a standard model-like Higgs boson decaying into two photons in the mass range between 70 and 110 GeV are presented. The analysis uses the data set collected by the CMS experiment in proton-proton collisions at s=13TeV corresponding to integrated luminosities of 36.3fb−1, 41.5fb−1 and 54.4fb−1 during the 2016, 2017, and 2018 LHC running periods, respectively. No significant excess over the background expectation is observed and 95% confidence level upper limits are set on the product of the cross section and branching fraction for decays of an additional Higgs boson into two photons. The maximum deviation with respect to the background is seen for a mass hypothesis of 95.4 GeV with a local (global) significance of 2.9 (1.3) standard deviations. The observed upper limit ranges from 15 to 73 fb.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2025,
Search for bottom quark associated production of the standard model Higgs boson in final states with leptons in proton-proton collisions at s=13TeV
, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol: 860, ISSN: 0370-2693This Letter presents the first search for bottom quark associated production of the standard model Higgs boson, in final states with leptons. Higgs boson decays to pairs of tau leptons and pairs of leptonically decaying W bosons are considered. The search is performed using data collected from 2016 to 2018 by the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138fb−1. Upper limits at the 95% confidence level are placed on the signal strength for Higgs boson production in association with bottom quarks; the observed (expected) upper limit is 3.7 (6.1) times the standard model prediction.
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Journal articleDekkers S, Egede U, Fujii Y, et al., 2024,
Measurement of (Formula presented), (Formula presented), and (Formula presented) Decay Parameters Using (Formula presented) Decays
, Physical Review Letters, Vol: 133, ISSN: 0031-9007A comprehensive study of the angular distributions in the bottom-baryon decays (Formula presented), followed by (Formula presented) with (Formula presented) or (Formula presented) decays, is performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of (Formula presented) collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The decay parameters and the associated charge-parity ((Formula presented)) asymmetries are measured, with no significant (Formula presented) violation observed. For the first time, the (Formula presented) decay parameters are measured. The most precise measurements of the decay parameters (Formula presented), (Formula presented), and (Formula presented) are obtained for (Formula presented) decays and an independent measurement of the decay parameters for the strange-baryon (Formula presented) decay is provided. The results deepen our understanding of weak decay dynamics in baryon decays.
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Journal articleChatterjee S, Das I, 2024,
Desertion of anomalous magnetic transition and emergence of metallic state in Cu doped Eu2Ru2O7 pyrochlore.
, J Chem Phys, Vol: 161In this paper, we present a detailed investigation of the structural, magnetic, and electrical transport properties of Eu2-xCuxRu2O7 (x = 0, 0.2, 0.4) pyrochlores. X-ray diffraction measurements confirm the single-phase nature of all samples and also manifest the reduction of lattice parameters with the increase in copper doping concentration. The experimental results of the magnetic measurements indicate that an anomalous magnetic transition around 23 K arises due to the contribution of non-magnetic Eu3+ ions. The strength of this unnatural magnetic transition reduces with decreasing Eu concentration [i.e., with increasing copper doping (x)] and finally disappears for x = 0.4. Moreover, electrical transport measurements reveal a considerable decrease in resistivity for Cu doped samples compared to undoped samples, which indicates the increase in charge carrier concentration with increasing Cu content.
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Journal articlePal K, Dey S, Alam A, et al., 2024,
Revealing exchange bias in spin compensated systems for spintronics applications.
, Sci Rep, Vol: 14Antiferromagnetic materials offer potential for spintronic applications due to their resilience to magnetic field perturbations and lack of stray fields. Achieving exchange bias in these materials is crucial for certain applications; however, discovering such materials remains challenging due to their compensated spin structure. The quest for antiferromagnetic materials with exchange bias became a reality through our experimental study and theoretical simulation on Sr 2 FeIrO 6 and Sr 2 CoIrO 6 . This study also unveils the impact of ionic disorder and lattice distortion on magnetic properties. The presence of exchange bias in both materials, given their antiferromagnetic nature, is intriguing. This study opens up new avenues for achieving exchange bias in spin-compensated systems, offering potential for low power and ultra fast antiferromagnetic spintronic applications in future research endeavors.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Model-independent search for pair production of new bosons decaying into muons in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV
, Journal of High Energy Physics, Vol: 2024<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>The results of a model-independent search for the pair production of new bosons within a mass range of 0<jats:italic>.</jats:italic>21 <jats:italic>< m <</jats:italic> 60 GeV, are presented. This study utilizes events with a four-muon final state. We use two data sets, comprising 41<jats:italic>.</jats:italic>5 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup> and 59<jats:italic>.</jats:italic>7 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup> of proton-proton collisions at <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \sqrt{s} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math></jats:alternatives></jats:inline-formula> = 13 TeV, recorded in 2017 and 2018 by the CMS experiment at the CERN LHC. The study of the 2018 data set includes a search for displaced signatures of a new boson within the proper decay length range of 0 <jats:italic>< cτ <</jats:italic> 100 mm. Our results are combined with a previous CMS result, based on 35<jats:italic>.</jats:italic>9 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup> of proton-proton collisions at <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \sqrt{s} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math></jats:alternatives></jats:inline-formula> =
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
Measurement of CP Violation Observables in D^{+}→K^{-}K^{+}π^{+} Decays.
, Phys Rev Lett, Vol: 133A search for violation of the charge-parity (CP) symmetry in the D^{+}→K^{-}K^{+}π^{+} decay is presented, with proton-proton collision data corresponding to an integrated luminosity of 5.4 fb^{-1}, collected at a center-of-mass energy of 13 TeV with the LHCb detector. A novel model-independent technique is used to compare the D^{+} and D^{-} phase-space distributions, with instrumental asymmetries subtracted using the D_{s}^{+}→K^{-}K^{+}π^{+} decay as a control channel. The p value for the hypothesis of CP conservation is 8.1%. The CP asymmetry observables A_{CP|S}^{ϕπ^{+}}=(0.95±0.43_{stat}±0.26_{syst})×10^{-3} and A_{CP|S}^{K[over ¯]^{*0}K^{+}}=(-0.26±0.56_{stat}±0.18_{syst})×10^{-3} are also measured. These results show no evidence of CP violation and represent the most sensitive search performed through the phase space of a multibody decay.
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Journal articleMazumdar D, Das K, Das I, 2024,
Magnetic exchange coupled composite behavior in the doped manganite nanoparticles: A proposed phenomenological model
, Physica B: Condensed Matter, Vol: 695, ISSN: 0921-4526In this paper, we comprehensively investigate the isothermal magnetization behavior of doped perovskite manganite nanoparticles. The focus is on understanding the impact of variation of particle sizes on the soft and hard magnetic phases with respect to the changes in the coercive field and remanent magnetization, both theoretically and experimentally. The study seeks to correlate experimental findings with the proposed phenomenological model to gain deeper insights into the underlying mechanisms governing exchange coupling and anisotropy effects in the nanocrystalline composites. The proposed phenomenological model beautifully demonstrates how the values of saturation magnetization and coercive field changes with changing the particle size in the nanocrystalline La0.48Ca0.52MnO3 (LCMO48) and La0.46Ca0.54MnO3 (LCMO46) compounds. In addition, the model provide an insights into the limitations of critical radius, size and shape of the nanocrystalline particle. This investigation looks into how the size of particles affects their magnetic properties, specifically coercive field and remanent magnetization.
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Journal articleDas K, Mazumdar D, Das I, 2024,
Structural distortion driven polaronic transport and table-like magnetocaloric properties in polycrystalline Tb0.7Sr0.3MnO3 compound.
, Phys Chem Chem Phys, Vol: 26, Pages: 29987-30001This research mainly explores the structural, magnetic, magneto-transport, and magnetocaloric properties of the polycrystalline Tb0.7Sr0.3MnO3 compound. The results reveal a significant modification of the compound's ground state with increasing the strength of the magnetic field. The strong distortion in the crystal structure highly controls the magnetic and magneto-transport properties of the system. Along with this, a prominent 'table-like' nature in the temperature-dependent magnetic entropy change has been noticed, showcasing the potential application of the compound in the field of Ericsson refrigeration technology. Notably, a substantial low-field magnetoresistance is noticed around T ∼ 60 K. The temperature dependent electrical resistivity data can be well explained with the help of polaronic transport conduction mechanisms namely small-polaron hopping and variable-range hopping models. Various significant parameters are calculated and the system possesses a non-adiabatic polaron hopping mechanism with a large electron-phonon coupling constant. This investigation contributes valuable insights into the intricate dynamics of the 3d-4f exchange interaction and crystallographic distortion, shedding light on the underlying mechanisms governing the magnetic and electrical transport properties of the Sr-doped TbMnO3 compound.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for CP violation in $${{{\textrm{D}}}^{{0}}} \rightarrow {{\textrm{K}} _{\text {S}}^{{0}}} {{\textrm{K}} _{\text {S}}^{{0}}} $$ decays in proton–proton collisions at $$\sqrt{s} = 13\,\text {Te}\hspace{-.08em}\text {V} $$
, The European Physical Journal C, Vol: 84<jats:title>Abstract</jats:title><jats:p>A search is reported for charge-parity <jats:inline-formula><jats:alternatives><jats:tex-math>$$CP$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>CP</mml:mi> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> violation in <jats:inline-formula><jats:alternatives><jats:tex-math>$${{{\textrm{D}}}^{{0}}} \rightarrow {{\textrm{K}} _{\text {S}}^{{0}}} {{\textrm{K}} _{\text {S}}^{{0}}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mtext>D</mml:mtext> </mml:mrow> <mml:mn>0</mml:mn> </mml:msup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mtext>K</mml:mtext> <mml:mrow> <mml:mtext>S</mml:mtext> </mml:mrow> <mml:mn>0</mml:mn> </mml:msubsup> <mml:msubsup> <mml:mtext>K</mml:mtext> <mml:mrow> <mml:mtext>S</mml:mtext> </mml:mrow> <mml:mn>0</mml:mn> </mml:msubsup> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> decays, using data collected in proton–proton collisions at <jats:inline-formula><jats:alte
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Measurement of boosted Higgs bosons produced via vector boson fusion or gluon fusion in the H → $$ \textrm{b}\overline{\textrm{b}} $$ decay mode using LHC proton-proton collision data at $$ \sqrt{s} $$ = 13 TeV
, Journal of High Energy Physics, Vol: 2024<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>A measurement is performed of Higgs bosons produced with high transverse momentum (<jats:italic>p</jats:italic><jats:sub>T</jats:sub>) via vector boson or gluon fusion in proton-proton collisions. The result is based on a data set with a center-of-mass energy of 13 TeV collected in 2016–2018 with the CMS detector at the LHC and corresponds to an integrated luminosity of 138 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup>. The decay of a high-<jats:italic>p</jats:italic><jats:sub>T</jats:sub> Higgs boson to a boosted bottom quark-antiquark pair is selected using large-radius jets and employing jet substructure and heavy-flavor taggers based on machine learning techniques. Independent regions targeting the vector boson and gluon fusion mechanisms are defined based on the topology of two quark-initiated jets with large pseudorapidity separation. The signal strengths for both processes are extracted simultaneously by performing a maximum likelihood fit to data in the large-radius jet mass distribution. The observed signal strengths relative to the standard model expectation are <jats:inline-formula><jats:alternatives><jats:tex-math>$$ {4.9}_{-1.6}^{+1.9} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mn>4.9</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1.6</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>1.9</mml:mn> </mml:mrow> </mml:msubsup> </mml:
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
Measurement of the effective leptonic weak mixing angle
, Journal of High Energy Physics, Vol: 2024Using pp collision data at s = 13 TeV, recorded by the LHCb experiment between 2016 and 2018 and corresponding to an integrated luminosity of 5.4 fb−1, the forward-backward asymmetry in the pp → Z/γ* → μ+μ− process is measured. The measurement is carried out in ten intervals of the difference between the muon pseudorapidities, within a fiducial region covering dimuon masses between 66 and 116 GeV, muon pseudorapidities between 2.0 and 4.5 and muon transverse momenta above 20 GeV. These forward-backward asymmetries are compared with predictions, at next-to-leading order in the strong and electroweak couplings. The measured effective leptonic weak mixing angle is (Formula presented.) where the first uncertainty is statistical, the second arises from systematic uncertainties associated with the asymmetry measurement, and the third arises from uncertainties in the fit model used to extract sin2θeffℓ from the asymmetry measurement. This result is based on an arithmetic average of results using the CT18, MSHT20, and NNPDF31 parameterisations of the proton internal structure, and is consistent with previous measurements and with predictions from the global electroweak fit.
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Journal articleAbed Abud A, Abi B, Acciarri R, et al., 2024,
DUNE Phase II: scientific opportunities, detector concepts, technological solutions
, Journal of Instrumentation, Vol: 19The international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy toward the implementation of this leading-edge, large-scale science project. The 2023 report of the US Particle Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly endorsed DUNE Phase I and Phase II, as did the European Strategy for Particle Physics. While the construction of the DUNE Phase I is well underway, this White Paper focuses on DUNE Phase II planning. DUNE Phase-II consists of a third and fourth far detector (FD) module, an upgraded near detector complex, and an enhanced 2.1 MW beam. The fourth FD module is conceived as a "Module of Opportunity", aimed at expanding the physics opportunities, in addition to supporting the core DUNE science program, with more advanced technologies. This document highlights the increased science opportunities offered by the DUNE Phase II near and far detectors, including long-baseline neutrino oscillation physics, neutrino astrophysics, and physics beyond the standard model. It describes the DUNE Phase II near and far detector technologies and detector design concepts that are currently under consideration. A summary of key R & D goals and prototyping phases needed to realize the Phase II detector technical designs is also provided. DUNE's Phase II detectors, along with the increased beam power, will complete the full scope of DUNE, enabling a multi-decadal program of groundbreaking science with neutrinos.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Measurements of polarization and spin correlation and observation of entanglement in top quark pairs using (Formula presented) events from proton-proton collisions at (Formula presented)
, Physical Review D, Vol: 110, ISSN: 2470-0010Measurements of the polarization and spin correlation in top quark pairs ((Formula presented)) are presented using events with a single electron or muon and jets in the final state. The measurements are based on proton-proton collision data from the LHC at (Formula presented) collected by the CMS experiment, corresponding to an integrated luminosity of (Formula presented). All coefficients of the polarization vectors and the spin correlation matrix are extracted simultaneously by performing a binned likelihood fit to the data. The measurement is performed inclusively and in bins of additional observables, such as the mass of the (Formula presented) system and the top quark scattering angle in the (Formula presented) rest frame. The measured polarization and spin correlation are in agreement with the standard model. From the measured spin correlation, conclusions on the (Formula presented) spin entanglement are drawn by applying the Peres-Horodecki criterion. The standard model predicts entangled spins for (Formula presented) states at the production threshold and at high masses of the (Formula presented) system. Entanglement is observed for the first time in events at high (Formula presented) mass, where a large fraction of the (Formula presented) decays are spacelike separated, with an expected and observed significance of above 5 standard deviations.
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Journal articleAbbaneo D, Ahmad S, Albanese R, et al., 2024,
An integrated flux-symmetric spectrometer-magnet system for the SND@LHC experiment upgrade
, Journal of Instrumentation, Vol: 19The proposed upgrade of the SND@LHC experiment for the High Luminosity phase of the LHC (HL-LHC) will strongly benefit from the presence of a magnetized region, allowing for muon momentum and charge measurement. In this paper we describe an iron core magnet system that is partly integrated with the calorimeter and that is designed to respect the strict constraints from the available space in the experimental cavern, power consumption, and field requirements. Semi-analytical tools are introduced to explore the parameter space, in order to define the primary design options. A full 3-D analysis is then performed in order to validate the optimal choice, and to propose a conceptual design, including sizing of the components, detector performances and stray fields. Several technical options are also discussed, anticipating the design phase.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
The CMS statistical analysis and combination tool: COMBINE
, Computing and Software for Big Science, Vol: 8, ISSN: 2510-2036This paper describes the Combine software package used for statistical analyses by the CMS Collaboration. The package, originally designed to perform searches for a Higgs boson and the combined analysis of those searches, has evolved to become the statistical analysis tool presently used in the majority of measurements and searches performed by the CMS Collaboration. It is not specific to the CMS experiment, and this paper is intended to serve as a reference for users outside of the CMS Collaboration, providing an outline of the most salient features and capabilities. Readers are provided with the possibility to run Combine and reproduce examples provided in this paper using a publicly available container image. Since the package is constantly evolving to meet the demands of ever-increasing data sets and analysis sophistication, this paper cannot cover all details of Combine. However, the online documentation referenced within this paper provides an up-to-date and complete user guide.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Portable acceleration of CMS computing workflows with coprocessors as a service
, Computing and Software for Big Science, Vol: 8, ISSN: 2510-2036Computing demands for large scientific experiments, such as the CMS experiment at the CERN LHC, will increase dramatically in the next decades. To complement the future performance increases of software running on central processing units (CPUs), explorations of coprocessor usage in data processing hold great potential and interest. Coprocessors are a class of computer processors that supplement CPUs, often improving the execution of certain functions due to architectural design choices. We explore the approach of Services for Optimized Network Inference on Coprocessors (SONIC) and study the deployment of this as-a-service approach in large-scale data processing. In the studies, we take a data processing workflow of the CMS experiment and run the main workflow on CPUs, while offloading several machine learning (ML) inference tasks onto either remote or local coprocessors, specifically graphics processing units (GPUs). With experiments performed at Google Cloud, the Purdue Tier-2 computing center, and combinations of the two, we demonstrate the acceleration of these ML algorithms individually on coprocessors and the corresponding throughput improvement for the entire workflow. This approach can be easily generalized to different types of coprocessors and deployed on local CPUs without decreasing the throughput performance. We emphasize that the SONIC approach enables high coprocessor usage and enables the portability to run workflows on different types of coprocessors.
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Journal articleAalbers J, Akerib DS, Al Musalhi AK, et al., 2024,
Constraints on Covariant Dark-Matter-Nucleon Effective Field Theory Interactions from the First Science Run of the LUX-ZEPLIN Experiment.
, Phys Rev Lett, Vol: 133The LUX-ZEPLIN (LZ) experiment is a dual-phase xenon time project chamber operating in the Sanford Underground Research Facility in South Dakota, USA. We report on the results of a relativistic extension to the nonrelativistic effective field theory (NREFT) from a 5.5 t fiducial mass and 60 live days of exposure. We present constraints on couplings from covariant interactions arising from the coupling of vector, axial currents, and electric dipole moments of the nucleon to the magnetic and electric dipole moments of the weakly interacting massive particle which cannot be described by recasting previous results described by an NREFT. Using a profile-likelihood ratio analysis, in an energy region between 0 keV_{nr} to 270 keV_{nr}, we report 90% confidence level exclusion limits on the coupling strength of five interactions in both the isoscalar and isovector bases.
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Journal articleScandale W, Cerutti F, Esposito LS, et al., 2024,
Multiple scattering of positively charged particles moving near the (111) plane in a silicon single crystal
, EUROPEAN PHYSICAL JOURNAL PLUS, Vol: 139, ISSN: 2190-5444 -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Searches for pair-produced multijet resonances using data scouting in proton-proton collisions at sqrt[s]=13 TeV
, Physical Review Letters, Vol: 133, ISSN: 0031-9007Searches for pair-produced multijet signatures using data corresponding to an integrated luminosity of 128 fb−1 of proton-proton collisions at √𝑠=13 TeV are presented. A data scouting technique is employed to record events with low jet scalar transverse momentum sum values. The electroweak production of particles predicted in 𝑅-parity violating supersymmetric models is probed for the first time with fully hadronic final states. This is the first search for prompt hadronically decaying mass-degenerate higgsinos, and extends current exclusions on 𝑅-parity violating top squarks and gluinos.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for soft unclustered energy patterns in proton-proton collisions at 13 TeV
, Physical Review Letters, Vol: 133, ISSN: 0031-9007The first search for soft unclustered energy patterns (SUEPs) is performed using an integrated luminosity of 138 fb−1 of proton-proton collision data at √𝑠=13 TeV, collected in 2016–2018 by the CMS detector at the LHC. Such SUEPs are predicted by hidden valley models with a new, confining force with a large ’t Hooft coupling. In events with boosted topologies, selected by high-threshold hadronic triggers, the multiplicity and sphericity of clustered tracks are used to reject the background from standard model quantum chromodynamics. With no observed excess of events over the standard model expectation, limits are set on the cross section for production via gluon fusion of a scalar mediator with SUEP-like decays.
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
Probing the nature of the χ<inf>c1</inf>(3872) state using radiative decays
, Journal of High Energy Physics, Vol: 2024Abstract: The radiative decays χc1(3872) → ψ(2S) γ and χc1(3872) → J/ψγ are used to probe the nature of the χc1(3872) state using proton-proton collision data collected with the LHCb detector, corresponding to an integrated luminosity of 9 fb−1. Using the B+ → χc1(3872)K+ decay, the χc1(3872) → ψ(2S) γ process is observed for the first time and the ratio of its partial width to that of the χc1(3872) → J/ψγ decay is measured to be (Formula presented.) where the first uncertainty is statistical, the second systematic and the third is due to the uncertainties on the branching fractions of the ψ(2S) and J/ψ mesons. The measured ratio makes the interpretation of the χc1(3872) state as a pure D0D¯∗0 + D¯0 D*0 molecule questionable and strongly indicates a sizeable compact charmonium or tetraquark component within the χc1(3872) state.
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Journal articleAbratenko P, Alterkait O, Andrade Aldana D, et al., 2024,
Improving neutrino energy estimation of charged-current interaction events with recurrent neural networks in MicroBooNE
, Physical Review D, Vol: 110, ISSN: 2470-0010We present a deep learning-based method for estimating the neutrino energy of charged-current neutrino-argon interactions. We employ a recurrent neural network (RNN) architecture for neutrino energy estimation in the MicroBooNE experiment, utilizing liquid argon time projection chamber (LArTPC) detector technology. Traditional energy estimation approaches in LArTPCs, which largely rely on reconstructing and summing visible energies, often experience sizable biases and resolution smearing because of the complex nature of neutrino interactions and the detector response. The estimation of neutrino energy can be improved after considering the kinematics information of reconstructed final-state particles. Utilizing kinematic information of reconstructed particles, the deep learning-based approach shows improved resolution and reduced bias for the muon neutrino Monte Carlo simulation sample compared to the traditional approach. In order to address the common concern about the effectiveness of this method on experimental data, the RNN-based energy estimator is further examined and validated with dedicated data-simulation consistency tests using MicroBooNE data. We also assess its potential impact on a neutrino oscillation study after accounting for all statistical and systematic uncertainties and show that it enhances physics sensitivity. This method has good potential to improve the performance of other physics analyses.
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