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Journal article, 2027, , Physics Reports, Vol: 1205, Pages: 1-83, ISSN: 0370-1573
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Journal articleBelyaev A, Hayrapetyan A, Tumasyan A, et al., 2026, , Physical Review Letters, Vol: 137, ISSN: 0031-9007
<jats:p> The first measurement of coherent <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mi mathvariant="normal">ϒ</a:mi> <a:mo stretchy="false">(</a:mo> <a:mn>1</a:mn> <a:mi mathvariant="normal">S</a:mi> <a:mo stretchy="false">)</a:mo> </a:mrow> </a:math> meson photoproduction off heavy nuclei is performed using ultraperipheral lead-lead collisions collected by the CMS experiment at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The nuclear gluonic structure is probed at a nucleon momentum fraction of order <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mi>x</g:mi> <g:mo>∼</g:mo> <g:msup> <g:mn>10</g:mn> <g:mrow> <g:mo>−</g:mo> <g:mn>3</g:mn> </g:mrow> </g:msup> </g:math> , determined by the kinematics of the process. Owing to the large <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:mrow> <i:mi mathvariant="normal">ϒ</i:mi> <i:mo stretchy="false">(</i:mo> <i:mn>1</i:mn> <i:mi math
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Journal of High Energy Physics, Vol: 2026
<jats:title> A <jats:sc>bstract</jats:sc> </jats:title> <jats:p> A simultaneous measurement of 25 substructure observables is presented using large-radius jets with high transverse momentum from proton-proton collisions at <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s}=13 $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> </mml:math> </jats:alternatives> </jats:inline-formula> TeV. The measurement is carried out on dijet events and <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ t\overline{t} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> </jats:alternatives> </jats:inline-formula> events enriched in Lorentz-boosted W bosons and top quarks decaying hadronically. The three data samples consist of jets with one, two, or three prongs from the showering and hadronization of a gluon or light-flavo
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Journal articleAad G, Aakvaag E, Abbott B, et al., 2026, , Physical Review Letters, Vol: 137, ISSN: 0031-9007
<jats:p> This Letter presents a combination of searches for Higgs boson pair ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi>H</a:mi> <a:mi>H</a:mi> </a:math> ) production performed by the ATLAS and CMS Collaborations using proton-proton collision datasets recorded at <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:msqrt> <c:mi>s</c:mi> </c:msqrt> <c:mo>=</c:mo> <c:mn>13</c:mn> <c:mtext> </c:mtext> <c:mtext> </c:mtext> <c:mi>TeV</c:mi> </c:math> during the Large Hadron Collider Run 2, corresponding to integrated luminosities ranging between 126 and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mn>140</e:mn> <e:mtext> </e:mtext> <e:mtext> </e:mtext> <e:msup> <e:mi>fb</e:mi> <e:mrow> <e:mo>−</e:mo> <e:mn>1</e:mn> </e:mrow> </e:msup> </e:math> . The upper limit at the 95% confidence level on the total <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> &l
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Journal of High Energy Physics, Vol: 2026
<jats:title> A <jats:sc>bstract</jats:sc> </jats:title> <jats:p> A search is presented for single production of a vector-like top quark T, decaying into the standard model top quark and Higgs boson, in a final state including two opposite-sign leptons (electrons or muons), jets, and missing transverse momentum. The data were recorded by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC in the years 2016–2018, and corresponding to an integrated luminosity of up to 138 fb <jats:sup> <jats:italic>−</jats:italic> 1 </jats:sup> . No excess in data over the background expectations is observed. Upper limits at 95% confidence level on the product of the T production cross section and its decay branching fraction to tH are set. The observed limits are 2.0 pb at a T mass <jats:italic>M</jats:italic> <jats:sub>T</jats:sub> = 600 GeV and 0.3 pb at <jats:italic>M</jats:italic> <jats:sub>T</jats:sub> = 1200 GeV, with a minimum of 0.1 pb at <jats:italic>M</jats:italic> <jats:sub>T</jats:sub> = 1000 GeV. This is the first search for single vector-like T quark production, followed by a decay to a top quark and the Higgs boson, in opposite-sign dilepton final states. </jats:p>
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Physical Review Letters, Vol: 137, ISSN: 0031-9007
<jats:p> A search for supersymmetric electroweakinos is performed using events with a low-momentum (soft) isolated track and large missing transverse momentum, targeting nearly mass-degenerate higgsinolike charginos and neutralinos. For mass splittings of 0.3–1 GeV, the chargino decays to the lightest neutralino and a low-momentum pion, which can produce a soft, potentially displaced track. A parametrized neural network separates signal from background using kinematic and impact parameter information. The analysis uses <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mn>138</a:mn> <a:mtext> </a:mtext> <a:mtext> </a:mtext> <a:msup> <a:mrow> <a:mi>fb</a:mi> </a:mrow> <a:mrow> <a:mo>−</a:mo> <a:mn>1</a:mn> </a:mrow> </a:msup> </a:mrow> </a:math> of proton-proton collision data at a center-of-mass energy of 13 TeV recorded with the CMS detector. No significant excess above the standard model expectation is observed. At 95% confidence level, the considered higgsino model is excluded for mass splittings in the range 0.28–1.15 GeV and for chargino masses up to 185 GeV, setting stringent constraints on natural supersymmetry scenarios. </jats:p>
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2026, , Physical Review Letters, Vol: 137, ISSN: 0031-9007
<jats:p> A search is presented for the production of two additional Higgs bosons from an off-shell boson, where both additional particles decay to <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mi>τ</a:mi> </a:mrow> </a:math> lepton pairs. The search is performed with a data sample collected with the CMS detector from proton-proton collisions at the LHC at <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mrow> <c:msqrt> <c:mrow> <c:mi>s</c:mi> </c:mrow> </c:msqrt> <c:mo>=</c:mo> <c:mn>13</c:mn> <c:mtext> </c:mtext> <c:mtext> </c:mtext> <c:mrow> <c:mtext>TeV</c:mtext> </c:mrow> </c:mrow> </c:math> , corresponding to an integrated luminosity of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mrow> <e:mn>138</e:mn> <e:mtext> </e:mtext> <e:mtext> </e:mtext> <e:msup> <e:mrow> <e:mi>fb</e:mi> </e:mrow>
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Journal of High Energy Physics, Vol: 2026
<jats:title> A <jats:sc>bstract</jats:sc> </jats:title> <jats:p> A search is presented for a light charged Higgs boson H <jats:sup> <jats:italic>±</jats:italic> </jats:sup> in top quark pair production ( <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \mathrm{t}\overline{\mathrm{t}} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> </jats:alternatives> </jats:inline-formula> ), where one of the top quarks decays to an H <jats:sup> <jats:italic>±</jats:italic> </jats:sup> and a bottom quark, while the other decays to a W <jats:sup>∓</jats:sup> boson and a bottom quark. The H <jats:sup> <jats:italic>±</jats:italic> </jats:sup> is assumed to decay into a charm and a strange quark, whereas the W <jats:sup>∓</jats:sup> boson decays into a charged lepton (electron or muon) and a neutrino. Results are reported based on proton-proton collision data at <jats:inline-formula>
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Journal articleAprile E, Aalbers J, Abe K, et al., 2026, , Physical Review Letters, Vol: 137, ISSN: 0031-9007
<jats:p> We report on a search for sub-GeV dark matter upscattered via the solar reflection mechanism in the heavy mediator scenario. Under the standard halo model, keV–MeV dark matter produces nuclear recoils with energies below the detection threshold of liquid xenon time projection chambers. We enhance sensitivity to low-mass dark matter (DM) by considering dark matter–electron scattering, employing dedicated event selections to reduce the detection threshold and exploiting the additional kinetic energy imparted to the dark matter particle by solar upscattering. Using XENON1T ionization-only and XENONnT low-energy electronic recoil datasets, we exclude previously unconstrained DM-electron scattering cross section for masses between 4.6 and <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mn>20</a:mn> <a:mtext> </a:mtext> <a:mtext> </a:mtext> <a:mrow> <a:mi>keV</a:mi> <a:mo>/</a:mo> </a:mrow> <a:msup> <a:mi>c</a:mi> <a:mn>2</a:mn> </a:msup> </a:math> and between 0.2 and <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mrow> <c:mn>2</c:mn> <c:mtext> </c:mtext> <c:mtext> </c:mtext> <c:mi>MeV</c:mi> <c:mo>/</c:mo> <c:msup> <c:mr
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Journal articleAaij R, Abdelfatah M, Abdelmotteleb ASW, et al., 2026, , Phys Rev Lett, Vol: 137
A precision measurement of the muon charge asymmetry from W-boson decays in proton-proton collisions at sqrt[s]=13 TeV is presented. The analysis utilizes data corresponding to an integrated luminosity of 5.1 fb^{-1}, recorded by the LHCb detector during 2016, 2017, and 2018. The asymmetry is measured for muons with transverse momentum between 25 and 55 GeV and pseudorapidity between 2.0 and 4.5. This result represents the most precise determination of the muon charge asymmetry in the forward region to date, exhibiting excellent agreement with next-to-next-to-leading-order predictions in perturbative quantum chromodynamics. The measured asymmetries are corrected for experimental efficiencies, resolution, and final-state photon radiation.
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Journal articleAkerib DS, Al Musalhi AK, Alder F, et al., 2026, , Phys Rev Lett, Vol: 137
We report results from searches for new physics models through electron recoils using data collected by the LUX-ZEPLIN experiment during its first two science runs, with a total exposure of 4.2 tonne-years. The observed data are consistent with a background-only hypothesis. Constraints are derived for electromagnetic interactions of solar neutrinos, solar axionlike particles (ALPs), mirror dark matter, and the absorption of bosonic dark matter candidates. The inverse Primakoff process for ^{57}Fe deexcitation solar ALPs is considered for the first time. These results represent the most stringent constraints to date on keV-scale Primakoff and ^{57}Fe solar ALPs, bosonic dark matter, mirror dark matter, and neutrino millicharge, while remaining competitive for the other signal models investigated.
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Physical Review D, Vol: 114, ISSN: 2470-0010
<jats:p> A new technique is developed to identify dielectrons ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:msup> <a:mi>e</a:mi> <a:mo>+</a:mo> </a:msup> <a:msup> <a:mi>e</a:mi> <a:mo>−</a:mo> </a:msup> </a:mrow> </a:math> ) with Lorentz boost <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:msub> <c:mi>γ</c:mi> <c:mi mathvariant="normal">L</c:mi> </c:msub> <c:mo>></c:mo> <c:mn>20</c:mn> </c:math> that produce one single merged cluster in the electromagnetic calorimeter of the CMS detector. The identification uses two multivariate models: one for the case where both electron tracks are reconstructed, and another where only one of the tracks is reconstructed. The efficiency is determined using proton-proton collision data collected at a center-of-mass energy of 13 TeV. Boosted <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"> <f:mi>J</f:mi> <f:mo>/</f:mo> <f:mi>ψ</f:mi> </f:math> mesons decaying into <h:math xmlns:h="http://www.w3.org/199
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Phys Rev Lett, Vol: 137
A search for Higgs boson (H) production in association with two vector bosons (V=W, Z) via vector-boson scattering (VBS) is presented using proton-proton collision data collected at sqrt[s]=13 TeV by the CMS experiment, corresponding to an integrated luminosity of 138 fb^{-1}. Events containing two forward jets consistent with VBS, a large-radius jet from the decay of a boosted H to a pair of b quarks, and zero, one, or two charged leptons coming from V decays are selected. The process is excluded at 95% confidence level for observed (expected) values of the VVHH coupling modifier κ_{2V} outside the interval 0.40<κ_{2V}<1.60 (0.34<κ_{2V}<1.66), assuming standard model values for all other couplings, thus establishing a novel probe of the VVHH interaction. Constraints are also set on the individual κ_{2W} and κ_{2Z} coupling modifiers and on the allowed region in the κ_{2W}-κ_{2Z} plane.
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Journal articleMorgan K, Azuma T, Baptista G, et al., 2026, , IEEE Transactions on Applied Superconductivity, Vol: 36, ISSN: 1051-8223
antiProtonic Atom X-ray (PAX) spectroscopy is an experiment that aims to test strong-field quantum electrodynamics (QED) effects by performing high-precision X-ray spectroscopy of antiprotonic atoms. PAX will use a low-energy antiproton beam provided by the Extra Low ENergy Antiproton (ELENA) ring at the European Organization for Nuclear Research (CERN) to create antiprotonic atoms. A superconducting transition-edge sensor (TES) spectrometer will be used to measure the energy of transitions between circular Rydberg states in these atoms. The energy range of interest for the experiment spans 50 keV to 250 keV, and the desired precision for measuring the centroids of the emission lines is 10^{-5}. The spectrometer for PAX is intended to have four 96-pixel TES arrays and will be read out with a microwave superconducting quantum interference device (SQUID) multiplexer. As a step toward building the full instrument, we built a scaled-down version of the spectrometer that was installed at the TEst Line for Machine And Antimatter eXperiments (TELMAX) facility at ELENA in April 2025. The purpose of this deployment was to make an observation of X-ray emission by antiprotonic atoms and to better understand the effect of the pionic charged particle background due to antiproton annihilation on the performance of the TES array. This pilot spectrometer had an array of 60 TES pixels in a compact adiabatic demagnetization refrigerator cryostat. The sensors were read out with a microwave SQUID multiplexer. Each pixel consisted of a molybdenum/gold bilayer TES with a coplanar gold “landing pad” for a bulk tin absorber that was attached by an epoxy joint. We discuss the design of the TES pixels, the microwave SQUID readout, and the cryogenic platform. Finally, we present calibration data obtained at TELMAX using radioactive sources to assess the performance of the spectrometer in the antiproton beam-off condition.
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Physics Letters Section B Nuclear Elementary Particle and High Energy Physics, Vol: 880, ISSN: 0370-2693
A first search at the LHC for a new heavy resonance decaying to a top quark and a neutral scalar boson Ï• in the fully hadronic final state is presented, where the Ï• boson is identified by its decay into a bottom quark-antiquark pair. The search is focused on final states in which the decay products of the highly Lorentz boosted top quark and Ï• boson are each reconstructed as a single, large-radius jet with distinct substructure. The analysis is performed using proton-proton collision data at a center-of-mass energy of 13TeV, corresponding to an integrated luminosity of 138fb<sup>−1</sup>, recorded with the CMS detector at the LHC in 2016–2018. The single production of a vector-like top quark, T′, is used as a benchmark model for the signal process. The results of this search are combined with those of a previous CMS search in which semileptonic decays of the top quark were used. No significant excess of data is observed with respect to the background prediction. For the case where the neutral scalar is a standard model Higgs boson and the T′ quark width is 5% of its mass, T′ quark masses between 0.85 and 1.3TeV are excluded at 95% confidence level and the most stringent limits to date are set for masses above 2TeV. For other Ï• boson masses, upper limits as low as 0.1fb are set on the product of the T′ quark production cross section and branching fraction for its decay to a top quark and a Ï• boson.
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Journal articleWalker T, Marchant AL, Bentine E, et al., 2026, , Avs Quantum Science, Vol: 8
We present a high-flux source of cold strontium atoms based on a two-dimensional magneto-optical trap (2D MOT) and a Zeeman slower. We use the source to load a 3D MOT in a separate science chamber, observing a loading rate of 4 × 10<sup>10</sup> atoms / s—to our knowledge, the highest reported loading flux for strontium. To characterize the vacuum pressure in the science chamber, we load the atoms into a magnetic trap and measure a lifetime of between 8 and 24 s, depending on the oven temperature. Finally, we characterize the atom flux and velocity distributions from the oven and from the 2D MOT source, finding reasonable agreement with models in the free molecular flow regime. Our results show that it is possible to readily produce a cold strontium flux at comparable levels to those of alkali species, at oven temperatures compatible with long-term operation, and at vacuum pressures suitable for state-of-the-art quantum experiments. We make our design available at no cost to benefit researchers in the quantum community.
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Journal articleBelyaev A, Gevorgyan A, Hayrapetyan A, et al., 2026, , Physics Letters Section B Nuclear Elementary Particle and High Energy Physics, Vol: 880, ISSN: 0370-2693
High-energy partons lose energy while propagating through the hot, strongly interacting medium produced in ultrarelativistic nucleus-nucleus collisions, leading to a suppression of particle production at high transverse momentum (p <inf>T</inf>). The dependence of this energy loss on the size of the colliding nuclear system has yet to be firmly established experimentally. This Letter presents a systematic study of charged-particle suppression across four different nucleus-nucleus collision systems using nuclear modification factors (R <inf>AA</inf>) measured by the CMS Collaboration at the CERN LHC. Previous CMS measurements of R <inf>AA</inf> in oxygen-oxygen, xenon-xenon, and lead-lead collisions are recast with identical p <inf>T</inf> intervals and are complemented by the first measurement of the charged-particle R <inf>AA</inf> in neon-neon collisions at [b]s<inf>NN</inf>=5.36TeV. The neon-neon data correspond to an integrated luminosity of 0.76nb<sup>−1</sup>. The R <inf>AA</inf> in all collision systems examined show similar qualitative trends as a function of p <inf>T</inf>, but have a magnitude which is ordered with the nucleon number A . The R <inf>AA</inf> feature a downward slope at low p <inf>T</inf>, a local minimum at around 5–7GeV, and an upward slope with increasing p <inf>T</inf>. The R <inf>AA</inf> are also compared in terms of A <sup>1/3</sup>, which is proportional to the nuclear radius. Models including only initial-state nuclear effects fail to reproduce the observed trends, whereas energy loss models reproduce the trends in the region p<inf>T</inf>'9.6GeV.
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Journal article, 2026, , Journal of Physics G: Nuclear and Particle Physics, Vol: 53, Pages: 095001-095001, ISSN: 0954-3899
<jats:title>Abstract</jats:title> <jats:p> This paper presents a combination of searches for the nonresonant production of Higgs boson pairs (HH) in proton–proton collisions at a centre-of-mass energy of 13 TeV. The dataset was collected by the CMS experiment at the LHC from 2016 to 2018 and corresponds to a total integrated luminosity of 138 fb <jats:inline-formula> <jats:tex-math> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msup> <mml:mrow/> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> </jats:inline-formula> . The observed (expected) upper limit on the inclusive HH production cross-section relative to the standard model (SM) prediction is found to be 3.5 (2.5). Assuming all other Higgs boson couplings are equal to their SM values, the Higgs boson trilinear self-coupling modifier <jats:inline-formula> <jats:tex-math> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>κ</mml:mi> &
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , The European Physical Journal C, Vol: 86
<jats:title>Abstract</jats:title> <jats:p> The particle-flow (PF) algorithm constructs a global description of each particle collision by producing a comprehensive list of final-state particles, and is central to event reconstruction in the CMS experiment at the CERN LHC. The existing PF implementation relies on physics-motivated heuristics and assumptions that can be replaced by machine-learning (ML) models trained directly on simulated data and naturally suited to modern graphics processing units (GPUs). A state-of-the-art ML-based PF (MLPF) reconstruction algorithm, implemented within the CMS software framework, is presented. The MLPF algorithm performs a learnable full-event reconstruction on GPUs, generalizes across detector conditions and collision energies, and replaces multiple modular reconstruction steps with a single unified model. Physics performance comparable to standard PF reconstruction is achieved in both simulation and data, with improved jet energy resolution and inference time. In simulated top quark-antiquark events under LHC Run-3 (2023–2024) conditions, the jet energy resolution improves by 10–20% for jets with transverse momentum between 30–100 GeV. Inference time is evaluated using simulated multijet events, with a median of <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$20\,\hbox {ms}$$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>20</mml:mn> <mml:mspace/> <mml:mtext>ms</mml:mtext> </mml:mrow> </mml:math> </jats:alternatives> </jats:inl
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Phys Rev Lett, Vol: 137
Evidence of the production of two Z bosons and a photon in proton-proton collisions is reported for the first time in CMS. The analysis uses data collected by the CMS experiment between 2016 and 2018 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb^{-1}. Evidence for the process pp→ZZγ→4â„“γ (â„“=e, μ), with an observed (expected) significance of 3.7 (3.1) standard deviations in a fiducial region defined by p_{T}^{γ}>20 GeV, |η^{γ}|<2.4, ΔR(â„“,γ)>0.5, m_{Z} between 60 and 120 GeV, and the invariant mass of either of the two Z bosons combined with the photon (m_{Z_{γ}}) larger than 100 GeV, is reported. The measured (predicted) fiducial cross section is 60_{-22}^{+27} ab (47.56±0.04 ab). Additionally, the inclusive production of pp→4â„“γ is studied by removing the m_{Z_{γ}} requirement to include final state radiation where one Z boson decays to 2â„“γ, yielding an observed (expected) significance of 5.0 (4.2) standard deviations and a measured (predicted) fiducial cross section of 156_{-35}^{+39} ab (99.97±0.09 ab).
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Journal articleAprile E, Aalbers J, Abe K, et al., 2026, , Phys Rev Lett, Vol: 137
We report a 3.3σ measurement of coherent elastic neutrino-nucleus scattering from solar ^{8}B neutrinos using a 6.77 t×yr exposure from the XENONnT experiment, inferring a solar ^{8}B neutrino flux of (5_{-2}^{+3})×10^{6} cm^{-2} s^{-1}, consistent with previous measurements. In the presence of the ^{8}B "neutrino fog," we find no evidence for light dark matter, and observe diminishing returns in sensitivity with increasing exposure. A 93% increase in exposure from the previous search improves the median sensitivity to the nucleon scattering cross section for a 5 GeV/c^{2} spin-independent weakly interacting massive particle by 10%. The dataset was also used to measure the weak mixing angle at ∼0.02 GeV/c momentum transfer and constrain physics beyond the Standard Model.
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Journal articleAkerib DS, Al Musalhi AK, Alder F, et al., 2026, , Phys Rev Lett, Vol: 137
We present searches for light dark matter (DM) with masses 3-9 GeV/c^{2} in the presence of coherent elastic neutrino-nucleus scattering (CEνNS) from ^{8}B solar neutrinos with the LUX-ZEPLIN experiment. This analysis uses a 5.7 tonne-yr exposure with data collected between March 2023 and April 2025. In an energy range spanning 1-6 keV, we report no significant excess of events attributable to dark matter nuclear recoils, but we observe a significant signal from ^{8}B CEνNS interactions that is consistent with expectation. We set world-leading limits on spin-independent and spin-dependent-neutron DM-nucleon interactions for masses down to 5 GeV/c^{2}. In the no-dark-matter scenario, we observe a signal consistent with ^{8}B CEνNS events, corresponding to a 4.5σ statistical significance. This is the most significant evidence of ^{8}B CEνNS interactions and is enabled by robust background modeling and mitigation techniques. This demonstrates LZ's ability to detect rare signals at keV-scale energies.
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2026, , Phys Rev Lett, Vol: 137
The first measurement of the polarization of charm baryons by the LHCb experiment recorded in fixed-target mode is presented. The polarization of Λ_{c} baryons is studied in collisions of protons, at an energy of 2.51 TeV, incident on a gaseous target of neon, at a nucleon-nucleon center-of-mass energy of 68.6 GeV. The world's first measurement of separate-charge polarizations for Λ_{c}^{+} and Λ[over ¯]_{c}^{-} baryons is performed, determining P_{Λ_{c}^{+}}=(24±9±2)%, P_{Λ[over ¯]_{c}^{-}}=(-8±12±3)%, where the first uncertainty is statistical and the second systematic. The polarization is also measured in intervals of baryon transverse momentum and the Feynman-x variable.
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Phys Rev Lett, Vol: 137
The long-range collective flow of particles produced in oxygen-oxygen (O+O) and neon-neon (Ne+Ne) collisions is measured with the CMS detector at the CERN LHC. The data samples were collected at a center-of-mass energy per nucleon pair of 5.36 TeV, with integrated luminosities of 7 nb^{-1} and 0.8 nb^{-1} for O+O and Ne+Ne collisions, respectively. Two- and four-particle azimuthal correlations are measured over nearly five units of pseudorapidity. Significant elliptic (v_{2}) and triangular (v_{3}) flow harmonics are observed in both systems. The ratios of v_{n} coefficients between Ne+Ne and O+O collisions suggest sensitivity to the intrinsic nuclear structure of the respective Ne and O ions. Hydrodynamic models with ab initio nuclear structure inputs qualitatively reproduce the collision-overlap dependence of both the v_{n} values and the Ne+Ne to O+O ratios. These measurements provide new constraints when modeling the interplay of nuclear structure and collective dynamics in collisions of ^{16}O and ^{20}Ne ions, respectively.
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Journal articleAaij R, Abdelfatah M, Abdelmotteleb ASW, et al., 2026, , Phys Rev Lett, Vol: 137
A measurement of the flavor-untagged decay-time-integrated CP asymmetry in the flavor-specific decay B_{s}^{0}→D_{s}^{-}π^{+}, ⟨A_{untagged}^{s}⟩, is performed using proton-proton collision data collected by the LHCb experiment between 2016 and 2018 at a center-of-mass energy of 13 TeV, corresponding to a total integrated luminosity of 5.4 fb^{-1}. The CP asymmetry is measured in two D_{s}^{-} meson decay modes, D_{s}^{-}→K^{-}K^{+}π^{-} and D_{s}^{-}→π^{-}π^{+}π^{-}. The combined result, ⟨A_{untagged}^{s}⟩=(-1.4±5.9(stat)±1.1(syst))×10^{-3}, is consistent with the Standard Model expectation and provides a direct constraint on new physics in tree-level b-hadron decays.
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Journal articleAaij R, Abdelfatah M, Abdelmotteleb ASW, et al., 2026, , Phys Rev Lett, Vol: 137
The onset of nuclear effects in light-ion collisions is studied by measuring the ratio of D^{0} meson production between NeNe and OO collisions at a center-of-mass energy per nucleon pair of 5.36 TeV recorded by the LHCb detector. The D^{0} meson yields are measured differentially in transverse momentum (p_{T}) for 0.5<p_{T}<20 GeV in the rapidity (y) region 2.0<y<4.5, and are normalized to the total number of recorded inelastic nucleus-nucleus collisions in each data sample. The resulting production ratio shows evidence of variation as a function of p_{T}, which is inconsistent with predictions based on nuclear modification of nucleon structure alone. This measurement is consistent with the onset of quark-gluon plasma production with increasing nucleus size in high-energy nuclear collisions.
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2026, , Phys Rev Lett, Vol: 137
The first evidence for the decay B^{+}→π^{+}e^{+}e^{-} is reported using proton-proton collision data recorded by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb^{-1}. A signal excess with a significance of 3.2σ is observed and the branching fraction is measured to be B(B^{+}→π^{+}e^{+}e^{-})=(2.4_{-0.8}^{+0.9} _{-0.2}^{+0.4})×10^{-8}, where the first set of uncertainties is statistical and the second is systematic. The result is consistent with the Standard Model expectation.
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Phys Rev Lett, Vol: 137
Energetic quarks and gluons traversing a hot and dense quark-gluon plasma deposit energy and momentum into the medium before hadronizing to collimated sprays of particles, known as jets. This energy-momentum deposition is expected to produce medium responses, collectively known as jet wakes, with "diffusion wake" denoting a depletion of particles in the direction opposite to the propagating jet. The diffusion wake is studied by comparing dijet-hadron correlations measured in lead-lead (PbPb) and proton-proton (pp) collisions. The analysis uses PbPb and pp data recorded at a nucleon-nucleon (NN) center-of-mass energy sqrt[s_{NN}]=5.02 TeV with the CMS detector at the CERN LHC. By exploring how the dijet-hadron correlation distributions differ for various pseudorapidity separations of the two jets in the dijet, the presence of a jet diffusion wake is firmly established. The diffusion wake signal has a significance greater than 5 standard deviations for charged particles in the transverse momentum range 1<p_{T}<2 GeV. The measurements are compared with model predictions with and without jet wake effects, providing new insights into quark-gluon plasma properties and the formation of jet-induced wakes.
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Journal articleAbratenko P, Andrade Aldana D, Arellano L, et al., 2026, , Physical Review D, Vol: 114, ISSN: 2470-0010
<jats:p> We present a new measurement of the electron neutrino charged current cross section on argon without pions in the final state. This measurement uses the full MicroBooNE booster neutrino beam dataset of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mn>1.3</a:mn> <a:mo>×</a:mo> <a:msup> <a:mrow> <a:mn>10</a:mn> </a:mrow> <a:mrow> <a:mn>21</a:mn> </a:mrow> </a:msup> </a:mrow> </a:math> protons on target collected at Fermi National Accelerator Laboratory. Events are considered both with and without protons above the kinetic energy visibility threshold. Differential cross sections are extracted in proton and electron kinematics, including energy and angle relative to the neutrino beam direction. The relationship between the hadronic and leptonic systems is explored through the angle between the proton and electron directions. The resulting cross sections are compared to a variety of available generator predictions using different models of neutrino interactions. We find good agreement with most models in lepton kinematics and some discrepancies in the hadronic system modeling, particularly in proton angle. </jats:p>
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Journal articleHayrapetyan A, Makarenko V, Tumasyan A, et al., 2026, , Journal of High Energy Physics, Vol: 2026
<jats:title> A <jats:sc>bstract</jats:sc> </jats:title> <jats:p> A search for microscopic black holes, string balls, and electroweak sphalerons using proton-proton collisions at <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s}=13 $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> </mml:math> </jats:alternatives> </jats:inline-formula> TeV recorded with the CMS detector at the CERN LHC during the 2016–2018 data taking, and corresponding to an integrated luminosity of 138 fb <jats:sup> <jats:italic>−</jats:italic> 1 </jats:sup> , is presented. Two search strategies based on control samples in data are used. Model-independent limits on the cross section of physics phenomena with multiple energetic jets, leptons, and photons are set using a method that relies on the shape invariance of the scalar sum of the transverse momenta of all objects in the event. Model-dependent limits on black hole and sphaleron production are set using a newly introduced method that has been developed for the identification of collider events with distinct kinematic features by separating them into classes based on phase space proximity. In the context of models with large extra dimensions, semiclassical black holes and st
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