B. Ary dos Santos Garcia, D. Bergermann, A. Caldwell, V. Dabhi, C. Diaconu, J. Diehl, G. Dvali, J. Egge, E. Garutti, S. Heyminck, F. Hubaut, A. Ivanov, J. Jochum, S. Knirck, M. Kramer, D. Kreikemeyer-Lorenzo, C. Krieger, C. Lee, D. Leppla-Weber, X. Li, A. Lindner, B. Majorovits, J. P. A. Maldonado, A. Martini, A. Miyazaki, E. Öz, P. Pralavorio, G. Raffelt, J. Redondo, A. Ringwald, J. Schaffran, A. Schmidt, F. Steffen, C. Strandhagen, I. Usherov, H. Wang, G. Wieching
This paper presents the first search for dark matter axions with mass in the ranges 76.56 to 76.82 $mu$eV and 79.31 to 79.53 $mu$eV using a prototype setup for the MAgnetized Disk and Mirror Axion eXperiment (MADMAX). The experimental setup employs a dielectric haloscope consisting of three sapphire disks and a mirror to resonantly enhance the axion-induced microwave signal within the magnetic dipole field provided by the 1.6 T Morpurgo magnet at CERN. Over 14.5 days of data collection, no axion signal was detected. A 95% CL upper limit on the axion-photon coupling strength down to $|g_{agamma}| sim 2 times 10^{-11} mathrm{GeV}^{-1}$ is set in the targeted mass ranges, surpassing previous constraints, assuming a local axion dark matter density $rho_{a}$ of $0.3~mathrm{GeV}/mathrm{cm}^3$. This study marks the first axion dark matter search using a dielectric haloscope.
本文介绍了利用 "磁盘和镜子轴子实验"（MADMAX）原型装置首次搜索质量在76.56到76.82和79.31到79.53之间的暗物质轴子的情况。实验装置采用了一个由三个蓝宝石盘和一面镜子组成的介质卤化镜，在欧洲核子研究中心1.6 T Morpurgo磁铁提供的磁偶极子场内共振增强轴心诱导的微波信号。轴子-光子耦合强度的95% CL上限低至$|g_{agamma}| sim 2times 10^{-11}在目标质量范围内，假定本地轴心暗物质密度为0.3~mathrm{GeV}/mathrm{cm}^3$，则设定了超越先前约束的 "mathrm{GeV}^{-1}$"。这项研究标志着首次使用介电卤化镜搜索轴心暗物质。
{"title":"First search for axion dark matter with a Madmax prototype","authors":"B. Ary dos Santos Garcia, D. Bergermann, A. Caldwell, V. Dabhi, C. Diaconu, J. Diehl, G. Dvali, J. Egge, E. Garutti, S. Heyminck, F. Hubaut, A. Ivanov, J. Jochum, S. Knirck, M. Kramer, D. Kreikemeyer-Lorenzo, C. Krieger, C. Lee, D. Leppla-Weber, X. Li, A. Lindner, B. Majorovits, J. P. A. Maldonado, A. Martini, A. Miyazaki, E. Öz, P. Pralavorio, G. Raffelt, J. Redondo, A. Ringwald, J. Schaffran, A. Schmidt, F. Steffen, C. Strandhagen, I. Usherov, H. Wang, G. Wieching","doi":"arxiv-2409.11777","DOIUrl":"https://doi.org/arxiv-2409.11777","url":null,"abstract":"This paper presents the first search for dark matter axions with mass in the\u0000ranges 76.56 to 76.82 $mu$eV and 79.31 to 79.53 $mu$eV using a prototype\u0000setup for the MAgnetized Disk and Mirror Axion eXperiment (MADMAX). The\u0000experimental setup employs a dielectric haloscope consisting of three sapphire\u0000disks and a mirror to resonantly enhance the axion-induced microwave signal\u0000within the magnetic dipole field provided by the 1.6 T Morpurgo magnet at CERN.\u0000Over 14.5 days of data collection, no axion signal was detected. A 95% CL upper\u0000limit on the axion-photon coupling strength down to $|g_{agamma}| sim 2\u0000times 10^{-11} mathrm{GeV}^{-1}$ is set in the targeted mass ranges,\u0000surpassing previous constraints, assuming a local axion dark matter density\u0000$rho_{a}$ of $0.3~mathrm{GeV}/mathrm{cm}^3$. This study marks the first\u0000axion dark matter search using a dielectric haloscope.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inclusive cross-sections for top-quark pair production in association with charm quarks are measured with proton-proton collision data at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 140 fb$^{-1}$, collected with the ATLAS experiment at the LHC between 2015 and 2018. The measurements are performed by requiring one or two charged leptons (electrons and muons), two $b$-tagged jets, and at least one additional jet in the final state. A custom flavor-tagging algorithm is employed for the simultaneous identification of $b$-jets and $c$-jets. In a fiducial phase space that replicates the acceptance of the ATLAS detector, the cross-sections for $tbar{t}+ {geq} 2c$ and $tbar{t}+1c$ production are measured to be $1.28^{+0.27}_{-0.24};text{pb}$ and $6.4^{+1.0}_{-0.9};text{pb}$, respectively. The measurements are primarily limited by uncertainties in the modeling of inclusive $tbar{t}$ and $tbar{t}+bbar{b}$ production, in the calibration of the flavor-tagging algorithm, and by data statistics. Cross-section predictions from various $tbar{t}$ simulations are largely consistent with the measured cross-section values, though all underpredict the observed values by 0.5 to 2.0 standard deviations. In a phase-space volume without requirements on the $tbar{t}$ decay products and the jet multiplicity, the cross-section ratios of $tbar{t}+ {geq} 2c$ and $tbar{t}+1c$ to total $tbar{t}+text{jets}$ production are determined to be $(1.23 pm 0.25) %$ and $(8.8 pm 1.3) %$.
{"title":"Measurement of top-quark pair production in association with charm quarks in proton-proton collisions at $sqrt{s}=13$ TeV with the ATLAS detector","authors":"ATLAS Collaboration","doi":"arxiv-2409.11305","DOIUrl":"https://doi.org/arxiv-2409.11305","url":null,"abstract":"Inclusive cross-sections for top-quark pair production in association with\u0000charm quarks are measured with proton-proton collision data at a center-of-mass\u0000energy of 13 TeV corresponding to an integrated luminosity of 140 fb$^{-1}$,\u0000collected with the ATLAS experiment at the LHC between 2015 and 2018. The\u0000measurements are performed by requiring one or two charged leptons (electrons\u0000and muons), two $b$-tagged jets, and at least one additional jet in the final\u0000state. A custom flavor-tagging algorithm is employed for the simultaneous\u0000identification of $b$-jets and $c$-jets. In a fiducial phase space that\u0000replicates the acceptance of the ATLAS detector, the cross-sections for\u0000$tbar{t}+ {geq} 2c$ and $tbar{t}+1c$ production are measured to be\u0000$1.28^{+0.27}_{-0.24};text{pb}$ and $6.4^{+1.0}_{-0.9};text{pb}$,\u0000respectively. The measurements are primarily limited by uncertainties in the\u0000modeling of inclusive $tbar{t}$ and $tbar{t}+bbar{b}$ production, in the\u0000calibration of the flavor-tagging algorithm, and by data statistics.\u0000Cross-section predictions from various $tbar{t}$ simulations are largely\u0000consistent with the measured cross-section values, though all underpredict the\u0000observed values by 0.5 to 2.0 standard deviations. In a phase-space volume\u0000without requirements on the $tbar{t}$ decay products and the jet multiplicity,\u0000the cross-section ratios of $tbar{t}+ {geq} 2c$ and $tbar{t}+1c$ to total\u0000$tbar{t}+text{jets}$ production are determined to be $(1.23 pm 0.25) %$ and\u0000$(8.8 pm 1.3) %$.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Conceição, A. Guillén, B. S. González, M. Pimenta, B. Tomé
Gamma/hadron discrimination in ground-based gamma-ray observatories at the GeV energy range is challenging as traditional muon-based methods become less effective at lower energies. This work explores a novel gamma/hadron discrimination method for Extensive Air Shower arrays that analyzes the shower signal footprint patterns using advanced Vision Transformer (ViT) models. The robustness of this method against noise, including atmospheric muons and low-energy proton showers, demonstrates its potential for application in future gamma-ray observatories.
{"title":"Gamma/hadron discrimination through the analysis of the shower footprint at low energies","authors":"R. Conceição, A. Guillén, B. S. González, M. Pimenta, B. Tomé","doi":"arxiv-2409.11093","DOIUrl":"https://doi.org/arxiv-2409.11093","url":null,"abstract":"Gamma/hadron discrimination in ground-based gamma-ray observatories at the\u0000GeV energy range is challenging as traditional muon-based methods become less\u0000effective at lower energies. This work explores a novel gamma/hadron\u0000discrimination method for Extensive Air Shower arrays that analyzes the shower\u0000signal footprint patterns using advanced Vision Transformer (ViT) models. The\u0000robustness of this method against noise, including atmospheric muons and\u0000low-energy proton showers, demonstrates its potential for application in future\u0000gamma-ray observatories.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Measurements of the polarization and spin correlation in top quark pairs ($mathrm{tbar{t}}$) 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 $sqrt{s}$ = 13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138 fb$^{-1}$. 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 $mathrm{tbar{t}}$ system and the top quark scattering angle in the $mathrm{tbar{t}}$ rest frame. The measured polarization and spin correlation are in agreement with the standard model. From the measured spin correlation, conclusions on the $mathrm{tbar{t}}$ spin entanglement are drawn by applying the Peres-Horodecki criterion. The standard model predicts entangled spins for $mathrm{tbar{t}}$ states at the production threshold and at high masses of the $mathrm{tbar{t}}$ system. Entanglement is observed for the first time in events at high $mathrm{tbar{t}}$ mass, where a large fraction of the $mathrm{tbar{t}}$ decays are space-like separated, with an expected and observed significance of above 5 standard deviations.
{"title":"Measurements of polarization and spin correlation and observation of entanglement in top quark pairs using lepton+jets events from proton-proton collisions at $sqrt{s}$ = 13 TeV","authors":"CMS Collaboration","doi":"arxiv-2409.11067","DOIUrl":"https://doi.org/arxiv-2409.11067","url":null,"abstract":"Measurements of the polarization and spin correlation in top quark pairs\u0000($mathrm{tbar{t}}$) are presented using events with a single electron or muon\u0000and jets in the final state. The measurements are based on proton-proton\u0000collision data from the LHC at $sqrt{s}$ = 13 TeV collected by the CMS\u0000experiment, corresponding to an integrated luminosity of 138 fb$^{-1}$. All\u0000coefficients of the polarization vectors and the spin correlation matrix are\u0000extracted simultaneously by performing a binned likelihood fit to the data. The\u0000measurement is performed inclusively and in bins of additional observables,\u0000such as the mass of the $mathrm{tbar{t}}$ system and the top quark scattering\u0000angle in the $mathrm{tbar{t}}$ rest frame. The measured polarization and spin\u0000correlation are in agreement with the standard model. From the measured spin\u0000correlation, conclusions on the $mathrm{tbar{t}}$ spin entanglement are drawn\u0000by applying the Peres-Horodecki criterion. The standard model predicts\u0000entangled spins for $mathrm{tbar{t}}$ states at the production threshold and\u0000at high masses of the $mathrm{tbar{t}}$ system. Entanglement is observed for\u0000the first time in events at high $mathrm{tbar{t}}$ mass, where a large\u0000fraction of the $mathrm{tbar{t}}$ decays are space-like separated, with an\u0000expected and observed significance of above 5 standard deviations.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A search for light long-lived particles decaying to displaced jets is presented, using a data sample of proton-proton collisions at a center-of-mass energy of 13.6 TeV, corresponding to an integrated luminosity of 34.7 fb$^{-1}$, collected with the CMS detector at the CERN LHC in 2022. Novel trigger, reconstruction, and machine-learning techniques were developed for and employed in this search. After all selections, the observations are consistent with the background predictions. Limits are presented on the branching fraction of the Higgs boson to long-lived particles that subsequently decay to quark pairs or tau lepton pairs. An improvement by up to a factor of 10 is achieved over previous limits for models with long-lived particle masses smaller than 60 GeV and proper decay lengths smaller than 1 m. The first constraints are placed on the fraternal twin Higgs and folded supersymmetry models, where the lower bounds on the top quark partner mass reach up to 350 GeV for the fraternal twin Higgs model and 250 GeV for the folded supersymmetry model.
{"title":"Search for light long-lived particles decaying to displaced jets in proton-proton collisions at $sqrt{s}$ = 13.6 TeV","authors":"CMS Collaboration","doi":"arxiv-2409.10806","DOIUrl":"https://doi.org/arxiv-2409.10806","url":null,"abstract":"A search for light long-lived particles decaying to displaced jets is\u0000presented, using a data sample of proton-proton collisions at a center-of-mass\u0000energy of 13.6 TeV, corresponding to an integrated luminosity of 34.7\u0000fb$^{-1}$, collected with the CMS detector at the CERN LHC in 2022. Novel\u0000trigger, reconstruction, and machine-learning techniques were developed for and\u0000employed in this search. After all selections, the observations are consistent\u0000with the background predictions. Limits are presented on the branching fraction\u0000of the Higgs boson to long-lived particles that subsequently decay to quark\u0000pairs or tau lepton pairs. An improvement by up to a factor of 10 is achieved\u0000over previous limits for models with long-lived particle masses smaller than 60\u0000GeV and proper decay lengths smaller than 1 m. The first constraints are placed\u0000on the fraternal twin Higgs and folded supersymmetry models, where the lower\u0000bounds on the top quark partner mass reach up to 350 GeV for the fraternal twin\u0000Higgs model and 250 GeV for the folded supersymmetry model.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adriana Bungau, Jose Alonso, Roger Barlow, Larry Bartozsek, Janet Conrad, Michael Shaevitz, Joshua Spitz, Daniel Winklehner
With the ever increasing beam power at particle accelerator-based facilities for nuclear and particle physics, radioactive isotope production, and nuclear engineering, targets that can withstand this power, and shielding of secondary particles are becoming increasingly important. Here we present Monte Carlo (MC) calculations using the well-established Geant4 software to optimise and predict the antineutrino yield of a $^8$Li Decay-At-Rest (DAR) source. The source relies on 600~kW of beam power from a continuous wave proton beam impinging on a beryllium target, where spallation neutrons capture on $^7$Li to produce the $^8$Li. We further present an in-depth treatment of the neutron shielding surrounding this target. We show that we can produce the high antineutrino flux needed for the discovery-level experiment IsoDAR, searching for ``sterile'' neutrinos (predicted new fundamental particles) and other beyond standard model physics, while maintaining a neutron flux in the detector that is below natural backgrounds. The methods presented in this paper are easily transferable to other high-power targets and their associated shielding.
{"title":"Neutrino yield and neutron shielding calculations for a high-power target installed in an underground setting","authors":"Adriana Bungau, Jose Alonso, Roger Barlow, Larry Bartozsek, Janet Conrad, Michael Shaevitz, Joshua Spitz, Daniel Winklehner","doi":"arxiv-2409.10211","DOIUrl":"https://doi.org/arxiv-2409.10211","url":null,"abstract":"With the ever increasing beam power at particle accelerator-based facilities\u0000for nuclear and particle physics, radioactive isotope production, and nuclear\u0000engineering, targets that can withstand this power, and shielding of secondary\u0000particles are becoming increasingly important. Here we present Monte Carlo (MC)\u0000calculations using the well-established Geant4 software to optimise and predict\u0000the antineutrino yield of a $^8$Li Decay-At-Rest (DAR) source. The source\u0000relies on 600~kW of beam power from a continuous wave proton beam impinging on\u0000a beryllium target, where spallation neutrons capture on $^7$Li to produce the\u0000$^8$Li. We further present an in-depth treatment of the neutron shielding\u0000surrounding this target. We show that we can produce the high antineutrino flux\u0000needed for the discovery-level experiment IsoDAR, searching for ``sterile''\u0000neutrinos (predicted new fundamental particles) and other beyond standard model\u0000physics, while maintaining a neutron flux in the detector that is below natural\u0000backgrounds. The methods presented in this paper are easily transferable to\u0000other high-power targets and their associated shielding.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu. M. Andreev, D. Banerjee, B. Banto Oberhauser, J. Bernhard, P. Bisio, N. Charitonidis, P. Crivelli, E. Depero, A. V. Dermenev, S. V. Donskov, R. R. Dusaev, T. Enik, V. N. Frolov, A. Gardikiotis, S. V. Gertsenberger, S. Girod, S. N. Gninenko, M. Hösgen, R. Joosten, V. A. Kachanov, Y. Kambar, A. E. Karneyeu, E. A. Kasianova, G. Kekelidze, B. Ketzer, D. V. Kirpichnikov, M. M. Kirsanov, V. N. Kolosov, V. A. Kramarenko, L. V. Kravchuk, N. V. Krasnikov, S. V. Kuleshov, V. E. Lyubovitskij, V. Lysan, V. A. Matveev, R. Mena Fredes, R. G. Mena Yanssen, L. Molina Bueno, M. Mongillo, D. V. Peshekhonov, V. A. Polyakov, B. Radics, K. M. Salamatin, V. D. Samoylenko, D. A. Shchukin, O. Soto, H. Sieber, V. O. Tikhomirov, I. V. Tlisova, A. N. Toropin, M. Tuzi, B. M. Veit, P. V. Volkov, V. Yu. Volkov, I. V. Voronchikhin, J. Zamora-Saá, A. S. Zhevlakov
A search for Dark Sectors is performed using the unique M2 beam line at the CERN Super Proton Synchrotron. New particles ($X$) could be produced in the bremsstrahlung-like reaction of high energy 160 GeV muons impinging on an active target, $mu Nrightarrowmu NX$, followed by their decays, $Xrightarrowtext{invisible}$. The experimental signature would be a scattered single muon from the target, with about less than half of its initial energy and no activity in the sub-detectors located downstream the interaction point. The full sample of the 2022 run is analyzed through the missing energy/momentum channel, with a total statistics of $(1.98pm0.02)times10^{10}$ muons on target. We demonstrate that various muon-philic scenarios involving different types of mediators, such as scalar or vector particles, can be probed simultaneously with such a technique. For the vector-case, besides a $L_mu-L_tau$ $Z'$ vector boson, we also consider an invisibly decaying dark photon ($A'rightarrowtext{invisible}$). This search is complementary to NA64 running with electrons and positrons, thus, opening the possibility to expand the exploration of the thermal light dark matter parameter space by combining the results obtained with the three beams.
{"title":"Shedding light on Dark Sectors with high-energy muons at the NA64 experiment at the CERN SPS","authors":"Yu. M. Andreev, D. Banerjee, B. Banto Oberhauser, J. Bernhard, P. Bisio, N. Charitonidis, P. Crivelli, E. Depero, A. V. Dermenev, S. V. Donskov, R. R. Dusaev, T. Enik, V. N. Frolov, A. Gardikiotis, S. V. Gertsenberger, S. Girod, S. N. Gninenko, M. Hösgen, R. Joosten, V. A. Kachanov, Y. Kambar, A. E. Karneyeu, E. A. Kasianova, G. Kekelidze, B. Ketzer, D. V. Kirpichnikov, M. M. Kirsanov, V. N. Kolosov, V. A. Kramarenko, L. V. Kravchuk, N. V. Krasnikov, S. V. Kuleshov, V. E. Lyubovitskij, V. Lysan, V. A. Matveev, R. Mena Fredes, R. G. Mena Yanssen, L. Molina Bueno, M. Mongillo, D. V. Peshekhonov, V. A. Polyakov, B. Radics, K. M. Salamatin, V. D. Samoylenko, D. A. Shchukin, O. Soto, H. Sieber, V. O. Tikhomirov, I. V. Tlisova, A. N. Toropin, M. Tuzi, B. M. Veit, P. V. Volkov, V. Yu. Volkov, I. V. Voronchikhin, J. Zamora-Saá, A. S. Zhevlakov","doi":"arxiv-2409.10128","DOIUrl":"https://doi.org/arxiv-2409.10128","url":null,"abstract":"A search for Dark Sectors is performed using the unique M2 beam line at the\u0000CERN Super Proton Synchrotron. New particles ($X$) could be produced in the\u0000bremsstrahlung-like reaction of high energy 160 GeV muons impinging on an\u0000active target, $mu Nrightarrowmu NX$, followed by their decays,\u0000$Xrightarrowtext{invisible}$. The experimental signature would be a scattered\u0000single muon from the target, with about less than half of its initial energy\u0000and no activity in the sub-detectors located downstream the interaction point.\u0000The full sample of the 2022 run is analyzed through the missing energy/momentum\u0000channel, with a total statistics of $(1.98pm0.02)times10^{10}$ muons on\u0000target. We demonstrate that various muon-philic scenarios involving different\u0000types of mediators, such as scalar or vector particles, can be probed\u0000simultaneously with such a technique. For the vector-case, besides a\u0000$L_mu-L_tau$ $Z'$ vector boson, we also consider an invisibly decaying dark\u0000photon ($A'rightarrowtext{invisible}$). This search is complementary to NA64\u0000running with electrons and positrons, thus, opening the possibility to expand\u0000the exploration of the thermal light dark matter parameter space by combining\u0000the results obtained with the three beams.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. V. Kulik, S. N. Filippov, E. N. Gushchin, A. A. Khudyakov, V. I. Kravtsov, Yu. G. Kudenko, A. Yu. Polyarush, A. V. Artamonov, S. V. Donskov, A. P. Filin, A. M. Gorin, A. V. Inyakin, G. V. Khaustov, S. A. Kholodenko, V. N. Kolosov, A. K. Konoplyannikov, V. F. Kurshetsov, V. A. Lishin, M. V. Medynsky, V. F. Obraztsov, A. V. Okhotnikov, V. A. Polyakov, V. I. Romanovsky, V. I. Rykalin, A. S. Sadovsky, V. D. Samoylenko, I. S. Tiurin, V. A. Uvarov, O. P. Yushchenko
A search for the $K^{+} to pi^{0}pi^{0}pi^{0}e^+nu$ decay is performed by the OKA collaboration. The search is based on $3.65 times 10^9 ~ K^+$ decays. No signal is observed. The upper limit set is $BR(K^{+} to pi^{0}pi^{0}pi^{0}e^+nu) < 5.4times 10^{-8} ~ 90%$ CL, 65 times lower than the one currently listed by PDG.
{"title":"The upper limit on the $K^+ to π^0π^0π^0e^+ν$ decay","authors":"A. V. Kulik, S. N. Filippov, E. N. Gushchin, A. A. Khudyakov, V. I. Kravtsov, Yu. G. Kudenko, A. Yu. Polyarush, A. V. Artamonov, S. V. Donskov, A. P. Filin, A. M. Gorin, A. V. Inyakin, G. V. Khaustov, S. A. Kholodenko, V. N. Kolosov, A. K. Konoplyannikov, V. F. Kurshetsov, V. A. Lishin, M. V. Medynsky, V. F. Obraztsov, A. V. Okhotnikov, V. A. Polyakov, V. I. Romanovsky, V. I. Rykalin, A. S. Sadovsky, V. D. Samoylenko, I. S. Tiurin, V. A. Uvarov, O. P. Yushchenko","doi":"arxiv-2409.08817","DOIUrl":"https://doi.org/arxiv-2409.08817","url":null,"abstract":"A search for the $K^{+} to pi^{0}pi^{0}pi^{0}e^+nu$ decay is performed\u0000by the OKA collaboration. The search is based on $3.65 times 10^9 ~ K^+$\u0000decays. No signal is observed. The upper limit set is $BR(K^{+} to\u0000pi^{0}pi^{0}pi^{0}e^+nu) < 5.4times 10^{-8} ~ 90%$ CL, 65 times lower\u0000than the one currently listed by PDG.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The FoCal is a high-granularity forward calorimeter to be installed as an ALICE upgrade subsystem during the LHC Long Shutdown 3 and take data during the LHC Run 4. The FoCal detector, covering a pseudorapidity interval of $3.2 < eta < 5.8$, extends the ALICE physics program with the capability to investigate gluon Parton Distribution Functions (PDFs) in the low-$x$ regime, down to $x approx 10^{-6}$. FoCal measurements will provide experimental constraints for PDFs in a region of phasespace where experimental data is scarce, as well as enable the study of non-linear QCD effects like gluon saturation. The FoCal detector consists of two components. The highly-granular Si+W electromagnetic calorimeter (FoCal-E) with pad and pixel longitudinal and transverse segmented readout layers provides high spatial resolution for discriminating between isolated photons and decay photon pairs. The hadronic calorimeter (FoCal-H) is constructed from copper capillary tubes filled with scintillator fibers and is used for isolation energy measurement and jets. With this detector design, FoCal is capable of measuring direct photons, jets, and the photo-production of vector mesons such as the $J/psi$ in p$-$Pb and Pb$-$Pb ultra-peripheral collisions. In addition, correlations of different probes can be studied, including $gamma$$-$jet, jet$-$jet and $pi^{0} - pi^{0}$ correlations. These measurements will place stringent constraints to various theoretical models incorporating non-linear QCD effects. This contribution gives an overview of the FoCal physics program. Also, recent experimental results of ever-improving prototypes of the detector, which were tested at the Test Beam facilities of CERN in the years 2021$-$2023, as well as simulation studies showcasing the robustness of the detector design and its physics potential are presented.
{"title":"Physics program and performance of the ALICE Forward Calorimeter upgrade (FoCal)","authors":"Laura Maria Huhtafor the ALICE collaboration","doi":"arxiv-2409.08983","DOIUrl":"https://doi.org/arxiv-2409.08983","url":null,"abstract":"The FoCal is a high-granularity forward calorimeter to be installed as an\u0000ALICE upgrade subsystem during the LHC Long Shutdown 3 and take data during the\u0000LHC Run 4. The FoCal detector, covering a pseudorapidity interval of $3.2 <\u0000eta < 5.8$, extends the ALICE physics program with the capability to\u0000investigate gluon Parton Distribution Functions (PDFs) in the low-$x$ regime,\u0000down to $x approx 10^{-6}$. FoCal measurements will provide experimental\u0000constraints for PDFs in a region of phasespace where experimental data is\u0000scarce, as well as enable the study of non-linear QCD effects like gluon\u0000saturation. The FoCal detector consists of two components. The highly-granular Si+W\u0000electromagnetic calorimeter (FoCal-E) with pad and pixel longitudinal and\u0000transverse segmented readout layers provides high spatial resolution for\u0000discriminating between isolated photons and decay photon pairs. The hadronic\u0000calorimeter (FoCal-H) is constructed from copper capillary tubes filled with\u0000scintillator fibers and is used for isolation energy measurement and jets. With\u0000this detector design, FoCal is capable of measuring direct photons, jets, and\u0000the photo-production of vector mesons such as the $J/psi$ in p$-$Pb and\u0000Pb$-$Pb ultra-peripheral collisions. In addition, correlations of different\u0000probes can be studied, including $gamma$$-$jet, jet$-$jet and $pi^{0} -\u0000pi^{0}$ correlations. These measurements will place stringent constraints to\u0000various theoretical models incorporating non-linear QCD effects. This contribution gives an overview of the FoCal physics program. Also,\u0000recent experimental results of ever-improving prototypes of the detector, which\u0000were tested at the Test Beam facilities of CERN in the years 2021$-$2023, as\u0000well as simulation studies showcasing the robustness of the detector design and\u0000its physics potential are presented.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rana Faryad Ali, Melanie Gascoine, Krzysztof Starosta, Byron D. Gates
Materials that possess a porous and defected structure can have a range of useful properties that are sought after, which include their tolerance to nuclear radiation, ability to efficiently store and release isotopes, to immobilize nuclear waste, and to exhibit phase stability even at elevated temperatures. Since nanoscale pores and surface structures can serve as sinks for radiation-induced amorphization, one dimensional (1D) porous nanorods due to their high surface-to-volume ratio have the potential for use as advanced materials in nuclear science applications. In this study, we demonstrate a synthesis and a detailed analysis of microporous 1D octahedral molecular sieves of disodium diniobate hydrate (Na2Nb2O6 H2O) or Sandia Octahedral Molecular Sieves (SOMS). In addition, the stability of these SOMS is evaluated following their exposure to elevated temperatures and neutron irradiation. A surfactant-assisted solvothermal method is used to prepare these SOMS-based nanorods. This relatively low temperature, solution-phase approach can form crystalline nanorods of microporous Na2Nb2O6 H2O. These 1D structures had an average diameter of approximately 50 nm and lengths greater than 1 micrometer. The nanorods adopted a defected microporous phase, which also exhibited a resistance to radiation induced amorphization. The dimensions, phase, and crystallinity of the SOMS-based nanorods after exposure to a high incident flux of neutrons were comparable to those of the as-synthesized products. The radiation tolerance of these microporous SOMS could be useful in the design of materials for nuclear reactors, resilient nuclear fuels, thermally resilient materials, high temperature catalysts, and durable materials for the handling and storage of radioactive waste.
{"title":"Disordered Microporous Sandia Octahedral Molecular Sieves are Tolerant to Neutron Radiation","authors":"Rana Faryad Ali, Melanie Gascoine, Krzysztof Starosta, Byron D. Gates","doi":"arxiv-2409.09146","DOIUrl":"https://doi.org/arxiv-2409.09146","url":null,"abstract":"Materials that possess a porous and defected structure can have a range of\u0000useful properties that are sought after, which include their tolerance to\u0000nuclear radiation, ability to efficiently store and release isotopes, to\u0000immobilize nuclear waste, and to exhibit phase stability even at elevated\u0000temperatures. Since nanoscale pores and surface structures can serve as sinks\u0000for radiation-induced amorphization, one dimensional (1D) porous nanorods due\u0000to their high surface-to-volume ratio have the potential for use as advanced\u0000materials in nuclear science applications. In this study, we demonstrate a\u0000synthesis and a detailed analysis of microporous 1D octahedral molecular sieves\u0000of disodium diniobate hydrate (Na2Nb2O6 H2O) or Sandia Octahedral Molecular\u0000Sieves (SOMS). In addition, the stability of these SOMS is evaluated following\u0000their exposure to elevated temperatures and neutron irradiation. A\u0000surfactant-assisted solvothermal method is used to prepare these SOMS-based\u0000nanorods. This relatively low temperature, solution-phase approach can form\u0000crystalline nanorods of microporous Na2Nb2O6 H2O. These 1D structures had an\u0000average diameter of approximately 50 nm and lengths greater than 1 micrometer.\u0000The nanorods adopted a defected microporous phase, which also exhibited a\u0000resistance to radiation induced amorphization. The dimensions, phase, and\u0000crystallinity of the SOMS-based nanorods after exposure to a high incident flux\u0000of neutrons were comparable to those of the as-synthesized products. The\u0000radiation tolerance of these microporous SOMS could be useful in the design of\u0000materials for nuclear reactors, resilient nuclear fuels, thermally resilient\u0000materials, high temperature catalysts, and durable materials for the handling\u0000and storage of radioactive waste.","PeriodicalId":501181,"journal":{"name":"arXiv - PHYS - High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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