This Letter presents a search for highly ionizing magnetic monopoles in 262$~mu$b$^{-1}$ of ultraperipheral Pb+Pb collision data at $sqrt{s_{_textrm{NN}}}=5.36$ TeV collected by the ATLAS detector at the LHC. A new methodology that exploits the properties of clusters of hits reconstructed in the innermost silicon detector layers is introduced to study highly ionizing particles in heavy-ion data. No significant excess above the background, which is estimated using a data-driven technique, is observed. Using a nonperturbative semiclassical model, upper limits at 95% confidence level are set on the cross-section for pair production of monopoles with a single Dirac magnetic charge in the mass range of 20-150 GeV. The search significantly improves on the previous cross-section limits for production of low-mass monopoles in ultraperipheral Pb+Pb collisions.
{"title":"Search for magnetic monopole pair production in ultraperipheral Pb+Pb collisions at $sqrt{s_{_textrm{NN}}}=5.36$ TeV with the ATLAS detector at the LHC","authors":"ATLAS Collaboration","doi":"arxiv-2408.11035","DOIUrl":"https://doi.org/arxiv-2408.11035","url":null,"abstract":"This Letter presents a search for highly ionizing magnetic monopoles in\u0000262$~mu$b$^{-1}$ of ultraperipheral Pb+Pb collision data at\u0000$sqrt{s_{_textrm{NN}}}=5.36$ TeV collected by the ATLAS detector at the LHC.\u0000A new methodology that exploits the properties of clusters of hits\u0000reconstructed in the innermost silicon detector layers is introduced to study\u0000highly ionizing particles in heavy-ion data. No significant excess above the\u0000background, which is estimated using a data-driven technique, is observed.\u0000Using a nonperturbative semiclassical model, upper limits at 95% confidence\u0000level are set on the cross-section for pair production of monopoles with a\u0000single Dirac magnetic charge in the mass range of 20-150 GeV. The search\u0000significantly improves on the previous cross-section limits for production of\u0000low-mass monopoles in ultraperipheral Pb+Pb collisions.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212830","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}
Mihaela Parvu, Piotr Krawczun, Vitaly A. Kudryavtsev
The sensitivity of underground experiments searching for rare events such as dark matter, neutrino interactions or several beyond the standard model phenomena is often limited by the background caused by neutrons from spontaneous fission and ($alpha,n$) reactions. A number of codes exist to calculate neutron yields and energy spectra due to these processes. In this paper we present new calculations of neutron production using the modified SOURCES4A code with recently updated cross-sections for ($alpha,n$) reactions and the comparison of the results with available experimental data. The cross-sections for ($alpha,n$) reactions in SOURCES4 have been taken from reliable experimental data where possible, complemented by the calculations with EMPIRE 2.19/3.2.3, TALYS 1.96 or evaluated data library JENDL-5 where the data were scarce or unavailable.
{"title":"Optimised neutron yield calculations from ($α,n$) reactions with the modified SOURCES4 code","authors":"Mihaela Parvu, Piotr Krawczun, Vitaly A. Kudryavtsev","doi":"arxiv-2408.10910","DOIUrl":"https://doi.org/arxiv-2408.10910","url":null,"abstract":"The sensitivity of underground experiments searching for rare events such as\u0000dark matter, neutrino interactions or several beyond the standard model\u0000phenomena is often limited by the background caused by neutrons from\u0000spontaneous fission and ($alpha,n$) reactions. A number of codes exist to\u0000calculate neutron yields and energy spectra due to these processes. In this\u0000paper we present new calculations of neutron production using the modified\u0000SOURCES4A code with recently updated cross-sections for ($alpha,n$) reactions\u0000and the comparison of the results with available experimental data. The\u0000cross-sections for ($alpha,n$) reactions in SOURCES4 have been taken from\u0000reliable experimental data where possible, complemented by the calculations\u0000with EMPIRE 2.19/3.2.3, TALYS 1.96 or evaluated data library JENDL-5 where the\u0000data were scarce or unavailable.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212831","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}
Naohiko Otuka, Kenichi Tada, Oscar Cabellos, Osamu Iwamoto
The uranium-233 neutron capture cross section between 3 keV and 1 MeV was evaluated with the new alpha value recently measured at the Los Alamos National Laboratory LANCE facility and compiled in the EXFOR library. The obtained capture cross section is systematically lower than those in the latest versions of the major general purpose nuclear data libraries, and the reduction from the JENDL-5 library is close to 50% around 20 keV. The newly evaluated cross section was benchmarked against 166 criticality experiments chosen from the ICSBEP handbook by performing Monte Carlo neutron transport calculation with the JENDL-5 library, and slight reduction of the cumulative chi-square value was achieved by adoption of the newly evaluated capture cross section.
{"title":"Evaluation of uranium-233 neutron capture cross section in keV region","authors":"Naohiko Otuka, Kenichi Tada, Oscar Cabellos, Osamu Iwamoto","doi":"arxiv-2408.10098","DOIUrl":"https://doi.org/arxiv-2408.10098","url":null,"abstract":"The uranium-233 neutron capture cross section between 3 keV and 1 MeV was\u0000evaluated with the new alpha value recently measured at the Los Alamos National\u0000Laboratory LANCE facility and compiled in the EXFOR library. The obtained\u0000capture cross section is systematically lower than those in the latest versions\u0000of the major general purpose nuclear data libraries, and the reduction from the\u0000JENDL-5 library is close to 50% around 20 keV. The newly evaluated cross\u0000section was benchmarked against 166 criticality experiments chosen from the\u0000ICSBEP handbook by performing Monte Carlo neutron transport calculation with\u0000the JENDL-5 library, and slight reduction of the cumulative chi-square value\u0000was achieved by adoption of the newly evaluated capture cross section.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212833","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}
This paper presents a measurement of jet-track correlations in photon-jet events, using 1.72 nb$^{-1}$ of Pb+Pb data at $sqrt{s_{text{NN}}}$ = 5.02 TeV recorded with the ATLAS detector at the LHC. Events with energetic photon-jet pairs are selected, where the photon and jet are approximately back-to-back in azimuth. The angular correlation between jets and charged-particle tracks with transverse momentum ($p_text{T}$) in the range 0.5-2.0 GeV in the hemisphere opposite to the jet, $|Deltaphitext{(jet,track)}|>pi/2$, is measured as a function of their relative pseudorapidity difference, $|Deltaetatext{(jet,track)}|$. In central Pb+Pb collisions, these correlations are predicted to be sensitive to the diffusion wake in the quark-gluon plasma resulting from the lost energy of high-$p_text{T}$ partons traversing the plasma, with a characteristic modification as a function of $|Deltaetatext{(jet,track)}|$. The correlations are examined with different selections on the jet-to-photon $p_text{T}$ ratio to select events with different degrees of energy loss. No diffusion wake signal is observed within the current sensitivity and upper limits at 95% confidence level on the diffusion wake amplitude are reported.
{"title":"Search for the jet-induced diffusion wake in the quark-gluon plasma via measurements of jet-track correlations in photon-jet events in Pb+Pb collisions at $sqrt{mathrm{s}_{mathrm{NN}}}$ = 5.02 TeV with the ATLAS detector","authors":"ATLAS Collaboration","doi":"arxiv-2408.08599","DOIUrl":"https://doi.org/arxiv-2408.08599","url":null,"abstract":"This paper presents a measurement of jet-track correlations in photon-jet\u0000events, using 1.72 nb$^{-1}$ of Pb+Pb data at $sqrt{s_{text{NN}}}$ = 5.02 TeV\u0000recorded with the ATLAS detector at the LHC. Events with energetic photon-jet\u0000pairs are selected, where the photon and jet are approximately back-to-back in\u0000azimuth. The angular correlation between jets and charged-particle tracks with\u0000transverse momentum ($p_text{T}$) in the range 0.5-2.0 GeV in the hemisphere\u0000opposite to the jet, $|Deltaphitext{(jet,track)}|>pi/2$, is measured as a\u0000function of their relative pseudorapidity difference,\u0000$|Deltaetatext{(jet,track)}|$. In central Pb+Pb collisions, these\u0000correlations are predicted to be sensitive to the diffusion wake in the\u0000quark-gluon plasma resulting from the lost energy of high-$p_text{T}$ partons\u0000traversing the plasma, with a characteristic modification as a function of\u0000$|Deltaetatext{(jet,track)}|$. The correlations are examined with different\u0000selections on the jet-to-photon $p_text{T}$ ratio to select events with\u0000different degrees of energy loss. No diffusion wake signal is observed within\u0000the current sensitivity and upper limits at 95% confidence level on the\u0000diffusion wake amplitude are reported.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212835","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. Dubey, K. Czerski, Gokul Das H, A. Kowalska, N. Targosz-Sleczka, M. Kaczmarski, M. Valat
The discovery of a new, strong reaction channel of the deuteron-deuteron fusion at very low energies might have major consequences for the construction of a future clean and efficient energy source. Following the first theoretical and experimental indications for the existence of the deuteron-deuteron threshold resonance in the $^4$He nucleus and its dominant decay by the internal $e^+e^-$ pair creation, we present here an extensive experimental study confirming emission of high-energy electrons and positrons. A simultaneous use of Si charged particle detectors of different thicknesses and large volume NaI(Tl) and HPGe detectors has allowed for the first time to determine the branching ratio between emitted protons, neutrons and $e^+e^-$ pairs for deuteron energies down to 5 keV. The high-energy positrons could be unambiguously detected by their bremsstrahlung spectra and annihilation radiation, supported by the Monte Carlo Geant4 simulations. The theoretical calculations, based on a destructive interference between the threshold resonance and the known broad resonance in $^4$He, agree very well with experimentally observed increase of branching ratios for lowering projectile energies. The partial width of the threshold resonance for the $e^+e^-$ pair creation should be at least 10 times larger than that of the proton channel.
{"title":"Experimental signatures of a new channel of the DD reaction at very-low energy","authors":"R. Dubey, K. Czerski, Gokul Das H, A. Kowalska, N. Targosz-Sleczka, M. Kaczmarski, M. Valat","doi":"arxiv-2408.07567","DOIUrl":"https://doi.org/arxiv-2408.07567","url":null,"abstract":"The discovery of a new, strong reaction channel of the deuteron-deuteron\u0000fusion at very low energies might have major consequences for the construction\u0000of a future clean and efficient energy source. Following the first theoretical\u0000and experimental indications for the existence of the deuteron-deuteron\u0000threshold resonance in the $^4$He nucleus and its dominant decay by the\u0000internal $e^+e^-$ pair creation, we present here an extensive experimental\u0000study confirming emission of high-energy electrons and positrons. A\u0000simultaneous use of Si charged particle detectors of different thicknesses and\u0000large volume NaI(Tl) and HPGe detectors has allowed for the first time to\u0000determine the branching ratio between emitted protons, neutrons and $e^+e^-$\u0000pairs for deuteron energies down to 5 keV. The high-energy positrons could be\u0000unambiguously detected by their bremsstrahlung spectra and annihilation\u0000radiation, supported by the Monte Carlo Geant4 simulations. The theoretical\u0000calculations, based on a destructive interference between the threshold\u0000resonance and the known broad resonance in $^4$He, agree very well with\u0000experimentally observed increase of branching ratios for lowering projectile\u0000energies. The partial width of the threshold resonance for the $e^+e^-$ pair\u0000creation should be at least 10 times larger than that of the proton channel.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212836","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}
We analyze data from the CsI, liquid Ar and Ge detectors of the COHERENT experiment and confirm within $1.5sigma$ that the measured elastic neutrino-nucleus scattering cross section is proportional to the square of the number of neutrons in the nucleus, as expected for coherent scattering in the standard model. We also show how various degeneracies involving nonstandard neutrino interaction parameters are broken in a combined analysis of the three datasets.
我们分析了 COHERENT 实验的 CsI、液态 Ar 和 Ge 探测器的数据，并在 1.5 美元的范围内证实，测得的弹性中微子-原子核散射截面与原子核中中子数目的平方成正比，正如标准模型中相干散射所预期的那样。我们还展示了在对三个数据集的综合分析中，涉及非标准中微子相互作用参数的各种退行性是如何被打破的。
{"title":"Testing for coherence and nonstandard neutrino interactions in COHERENT data","authors":"Jiajun Liao, Danny Marfatia, Jiajie Zhang","doi":"arxiv-2408.06255","DOIUrl":"https://doi.org/arxiv-2408.06255","url":null,"abstract":"We analyze data from the CsI, liquid Ar and Ge detectors of the COHERENT\u0000experiment and confirm within $1.5sigma$ that the measured elastic\u0000neutrino-nucleus scattering cross section is proportional to the square of the\u0000number of neutrons in the nucleus, as expected for coherent scattering in the\u0000standard model. We also show how various degeneracies involving nonstandard\u0000neutrino interaction parameters are broken in a combined analysis of the three\u0000datasets.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212834","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}
Isaac Kelly, Will Flanagan, Jacob Moldenhauer, William Charlton, Joseph Lapka, Donald Nolting
In light of the recently observed 800,000 barn thermal neutron absorption cross section of zirconium-88, this work investigates the fraction (isomeric yield ratio) of metastable versus ground state production of zirconium-89 and implications for ongoing measurements around zirconium-88 neutron absorption. The metastable state of zirconium-89 resides at 588 keV above the ground state with a half life of 4.2 minutes. A 5 $mu$Ci zirconium-88 sample was irradiated for 10 minutes in the core of a TRIGA Mark II nuclear research reactor and measured with a high purity germanium detector 3 minutes after irradiation. The isomeric yield ratio was measured to be 74.9$pm$0.6%.
鉴于最近观测到的锆-88 的 80 万谷仓热中子吸收截面，这项工作研究了锆-89 的逸散态与基态产生的比例（异构体产率比），以及对正在进行的锆-88 中子吸收测量的影响。在 TRIGA Mark II 核研究反应堆的堆芯中对 5 美元/μ$Ci 的锆-88 样品进行了 10 分钟的辐照，并在辐照 3 分钟后使用高纯度锗探测器进行了测量。测得异构体产率为 74.9%。
{"title":"Measurement of the Isomeric Yield Ratio of Zirconium-89m from Zirconium-88 Thermal Neutron Absorption","authors":"Isaac Kelly, Will Flanagan, Jacob Moldenhauer, William Charlton, Joseph Lapka, Donald Nolting","doi":"arxiv-2408.05367","DOIUrl":"https://doi.org/arxiv-2408.05367","url":null,"abstract":"In light of the recently observed 800,000 barn thermal neutron absorption\u0000cross section of zirconium-88, this work investigates the fraction (isomeric\u0000yield ratio) of metastable versus ground state production of zirconium-89 and\u0000implications for ongoing measurements around zirconium-88 neutron absorption.\u0000The metastable state of zirconium-89 resides at 588 keV above the ground state\u0000with a half life of 4.2 minutes. A 5 $mu$Ci zirconium-88 sample was irradiated\u0000for 10 minutes in the core of a TRIGA Mark II nuclear research reactor and\u0000measured with a high purity germanium detector 3 minutes after irradiation. The\u0000isomeric yield ratio was measured to be 74.9$pm$0.6%.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212837","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. M. Gesuè, G. F. Ciani, D. Piatti, A. Boeltzig, D. Rapagnani, M. Aliotta, C. Ananna, L. Barbieri, F. Barile, D. Bemmerer, A. Best, C. Broggini, C. G. Bruno, A. Caciolli, M. Campostrini, F. Casaburo, F. Cavanna, P. Colombetti, A. Compagnucci, P. Corvisiero, L. Csedreki, T. Davinson, G. M. De Gregorio, D. Dell'Aquila, R. Depalo, A. Di Leva, Z. Elekes, F. Ferraro, A. Formicola, Zs. Fülöp, G. Gervino, A. Guglielmetti, C. Gustavino, Gy. Gyürky, G. Imbriani, M. Junker, M. Lugaro, P. Marigo, J. Marsh, E. Masha, R. Menegazzo, D. Mercogliano, V. Paticchio, R. Perrino, P. Prati, V. Rigato, D. Robb, L. Schiavulli, R. S. Sidhu, J. Skowronski, O. Straniero, T. Szücs, S. Zavatarelli
The CNO cycle is one of the most important nuclear energy sources in stars. At temperatures of hydrostatic H-burning (20 MK $<$ T $<$ 80 MK) the $^{17}$O(p,$gamma$)$^{18}$F reaction rate is dominated by the poorly constrained 64.5~keV resonance. Here we report on the first direct measurements of its resonance strength and of the direct capture contribution at 142 keV, performed with a new high sensitivity setup at LUNA. The present resonance strength of $omegagamma_{(p, gamma)}$textsuperscript{bare} = (30 $pm$ 6textsubscript{stat} $pm$ 2textsubscript{syst})~peV is about a factor of 2 higher than the values in literature, leading to a $Gamma$textsubscript{p}textsuperscript{bare} = (34 $pm$ 7textsubscript{stat} $pm$ 3textsubscript{syst})~neV, in agreement with LUNA result from the (p,$alpha$) channel. Such agreement strengthen our understanding of the oxygen isotopic ratios measured in red giant stars and in O-rich presolar grains.
{"title":"First direct measurement of the 64.5 keV resonance strength in $^{17}$O(p,$γ$)$^{18}$F reaction","authors":"R. M. Gesuè, G. F. Ciani, D. Piatti, A. Boeltzig, D. Rapagnani, M. Aliotta, C. Ananna, L. Barbieri, F. Barile, D. Bemmerer, A. Best, C. Broggini, C. G. Bruno, A. Caciolli, M. Campostrini, F. Casaburo, F. Cavanna, P. Colombetti, A. Compagnucci, P. Corvisiero, L. Csedreki, T. Davinson, G. M. De Gregorio, D. Dell'Aquila, R. Depalo, A. Di Leva, Z. Elekes, F. Ferraro, A. Formicola, Zs. Fülöp, G. Gervino, A. Guglielmetti, C. Gustavino, Gy. Gyürky, G. Imbriani, M. Junker, M. Lugaro, P. Marigo, J. Marsh, E. Masha, R. Menegazzo, D. Mercogliano, V. Paticchio, R. Perrino, P. Prati, V. Rigato, D. Robb, L. Schiavulli, R. S. Sidhu, J. Skowronski, O. Straniero, T. Szücs, S. Zavatarelli","doi":"arxiv-2408.03015","DOIUrl":"https://doi.org/arxiv-2408.03015","url":null,"abstract":"The CNO cycle is one of the most important nuclear energy sources in stars.\u0000At temperatures of hydrostatic H-burning (20 MK $<$ T $<$ 80 MK) the\u0000$^{17}$O(p,$gamma$)$^{18}$F reaction rate is dominated by the poorly\u0000constrained 64.5~keV resonance. Here we report on the first direct measurements\u0000of its resonance strength and of the direct capture contribution at 142 keV,\u0000performed with a new high sensitivity setup at LUNA. The present resonance\u0000strength of $omegagamma_{(p, gamma)}$textsuperscript{bare} = (30 $pm$\u00006textsubscript{stat} $pm$ 2textsubscript{syst})~peV is about a factor of 2\u0000higher than the values in literature, leading to a\u0000$Gamma$textsubscript{p}textsuperscript{bare} = (34 $pm$\u00007textsubscript{stat} $pm$ 3textsubscript{syst})~neV, in agreement with LUNA\u0000result from the (p,$alpha$) channel. Such agreement strengthen our\u0000understanding of the oxygen isotopic ratios measured in red giant stars and in\u0000O-rich presolar grains.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946139","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}
L. Baudis, R. Biondi, A. Bismark, A. Clozza, C. Curceanu, M. Galloway, F. Napolitano, F. Piastra, K. Piscicchia, A. Porcelli, D. Ramírez García
The Pauli Exclusion Principle (PEP) appears from fundamental symmetries in quantum field theories, but its physical origin is still to be understood. High-precision experimental searches for small PEP violations permit testing key assumptions of the Standard Model with high sensitivity. We report on a dedicated measurement with Gator, a low-background, high-purity germanium detector operated at the Laboratori Nazionali del Gran Sasso, aimed at testing PEP-violating atomic transitions in lead. The experimental technique, relying on forming a new symmetry state by introducing electrons into the pre-existing electron system through a direct current, satisfies the conditions of the Messiah-Greenberg superselection rule. No PEP violation has been observed, and an upper limit on the PEP violation probability of $beta^2/2 < 4.8 cdot 10^{-29}$ (90% CL) is set. This improves the previous constraint from a comparable measurement by more than one order of magnitude.
保利排斥原理（PEP）出现于量子场论的基本对称性中，但它的物理起源仍有待了解。高精度实验搜索小的保利排斥原理违反情况，可以高灵敏度地检验标准模型的关键假设。我们报告了在大萨索国家实验室（Laboratori Nazionali del Gran Sasso）使用低背景、高纯度锗探测器 "盖特"（Gator）进行的专门测量，目的是测试铅中违反 PEP 的原子跃迁。该实验技术通过直流电将电子引入原有的电子系统来形成新的对称态，符合梅西亚-格林伯格超选择规则的条件。没有观测到PEP违反，并且设定了PEP违反概率的上限：$beta^2/2 < 4.8 cdot10^{-29}$（90% CL）。这比之前的可比测量约束提高了一个数量级以上。
{"title":"Search for Pauli Exclusion Principle Violations with Gator at LNGS","authors":"L. Baudis, R. Biondi, A. Bismark, A. Clozza, C. Curceanu, M. Galloway, F. Napolitano, F. Piastra, K. Piscicchia, A. Porcelli, D. Ramírez García","doi":"arxiv-2408.02500","DOIUrl":"https://doi.org/arxiv-2408.02500","url":null,"abstract":"The Pauli Exclusion Principle (PEP) appears from fundamental symmetries in\u0000quantum field theories, but its physical origin is still to be understood.\u0000High-precision experimental searches for small PEP violations permit testing\u0000key assumptions of the Standard Model with high sensitivity. We report on a\u0000dedicated measurement with Gator, a low-background, high-purity germanium\u0000detector operated at the Laboratori Nazionali del Gran Sasso, aimed at testing\u0000PEP-violating atomic transitions in lead. The experimental technique, relying\u0000on forming a new symmetry state by introducing electrons into the pre-existing\u0000electron system through a direct current, satisfies the conditions of the\u0000Messiah-Greenberg superselection rule. No PEP violation has been observed, and\u0000an upper limit on the PEP violation probability of $beta^2/2 < 4.8 cdot\u000010^{-29}$ (90% CL) is set. This improves the previous constraint from a\u0000comparable measurement by more than one order of magnitude.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946140","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}
J. Khuyagbaatar, R. A. Cantemir, Ch. E. Duellmann, E. Jaeger, B. Kindler, J. Krier, N. Kurz, B. Lommel, B. Schausten, A. Yakushev
The radioactive decay properties of $^{242}$Es were studied with significantly improved statistics compared to available literature data. This isotope was produced in the 3n evaporation channel of the fusion reaction of $^{48}$Ca+$^{197}$Au. A half-life of 16.9(8)~s was deduced from 662 $alpha$ decays of $^{242}$Es, resulting in an $alpha$-decay branching of 41(3)%. Twenty-six fission events with a half-life of 18.2$^{+4.5}_{-3.0}$~s were assigned to originate from the electron-capture delayed fission of $^{242}$Es. The probability for the electron-capture delayed fission was measured to be 0.015(4), which improves and resolves ambiguities in available experimental data. We discuss all known cases for electron-capture delayed fission in Es, Bk, and Am isotopes and compare experimental data with predictions from a recent semi-empirical model. A cross section of 27(3)~nb was measured for the production of $^{242}$Es.
{"title":"On the decay properties of the neutron-deficient isotope 242Es","authors":"J. Khuyagbaatar, R. A. Cantemir, Ch. E. Duellmann, E. Jaeger, B. Kindler, J. Krier, N. Kurz, B. Lommel, B. Schausten, A. Yakushev","doi":"arxiv-2408.01714","DOIUrl":"https://doi.org/arxiv-2408.01714","url":null,"abstract":"The radioactive decay properties of $^{242}$Es were studied with\u0000significantly improved statistics compared to available literature data. This\u0000isotope was produced in the 3n evaporation channel of the fusion reaction of\u0000$^{48}$Ca+$^{197}$Au. A half-life of 16.9(8)~s was deduced from 662 $alpha$\u0000decays of $^{242}$Es, resulting in an $alpha$-decay branching of 41(3)%.\u0000Twenty-six fission events with a half-life of 18.2$^{+4.5}_{-3.0}$~s were\u0000assigned to originate from the electron-capture delayed fission of $^{242}$Es.\u0000The probability for the electron-capture delayed fission was measured to be\u00000.015(4), which improves and resolves ambiguities in available experimental\u0000data. We discuss all known cases for electron-capture delayed fission in Es,\u0000Bk, and Am isotopes and compare experimental data with predictions from a\u0000recent semi-empirical model. A cross section of 27(3)~nb was measured for the\u0000production of $^{242}$Es.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946141","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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