{"title":"价部子分布的可能普遍极限","authors":"Christopher Leon , Misak Sargsian","doi":"10.1016/j.nuclphysa.2025.123243","DOIUrl":null,"url":null,"abstract":"<div><div>We report the observation of the existence of a possible universal limit for valence parton distributions that should exist once partonic degrees of freedom are relevant for high energy scattering from strongly interacting bound systems like a nucleon, meson or a few nucleon system at very short distances. Our observation is based on the notion that the Bjorken x weighted valence parton distribution function has a peak, <span><math><msub><mi>x</mi><mi>p</mi></msub></math></span>, that characterizes the average momentum fraction carried out by the valence quarks in the system. Within the residual mean-field model of the valence quark distribution we found that <span><math><msub><mi>x</mi><mi>p</mi></msub></math></span> has an upper limit: <span><math><mrow><msub><mi>x</mi><mi>p</mi></msub><mo>≤</mo><mfrac><mn>1</mn><mrow><mn>2</mn><mo>(</mo><msub><mi>n</mi><mi>V</mi></msub><mo>−</mo><mn>1</mn><mo>)</mo></mrow></mfrac></mrow></math></span>, where <span><math><msub><mi>n</mi><mi>V</mi></msub></math></span> is the number of valence quarks in the cluster embedded in the strongly interacting environment of the hadron. The existence of such a limit imposes a new constraint on choosing the starting resolution scale <span><math><msub><mi>Q</mi><mn>0</mn></msub></math></span> for PDFs. Our prediction for the nucleon is that <span><math><mrow><msub><mi>x</mi><mi>p</mi></msub><msub><mo>∣</mo><mrow><mi>Q</mi><mo>→</mo><msub><mi>Q</mi><mn>0</mn></msub></mrow></msub><mo>≤</mo><mfrac><mn>1</mn><mn>4</mn></mfrac></mrow></math></span>, which is in agreement with all the available valence PDFs that employ the standard approach for selecting starting <span><math><msub><mi>Q</mi><mn>0</mn></msub></math></span>. We also demonstrate how the existence of this limit can be used to verify the onset of quark-cluster structures in short range nucleon correlations in nuclei.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1064 ","pages":"Article 123243"},"PeriodicalIF":2.5000,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Possible universal limit for valence parton distributions\",\"authors\":\"Christopher Leon , Misak Sargsian\",\"doi\":\"10.1016/j.nuclphysa.2025.123243\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>We report the observation of the existence of a possible universal limit for valence parton distributions that should exist once partonic degrees of freedom are relevant for high energy scattering from strongly interacting bound systems like a nucleon, meson or a few nucleon system at very short distances. Our observation is based on the notion that the Bjorken x weighted valence parton distribution function has a peak, <span><math><msub><mi>x</mi><mi>p</mi></msub></math></span>, that characterizes the average momentum fraction carried out by the valence quarks in the system. Within the residual mean-field model of the valence quark distribution we found that <span><math><msub><mi>x</mi><mi>p</mi></msub></math></span> has an upper limit: <span><math><mrow><msub><mi>x</mi><mi>p</mi></msub><mo>≤</mo><mfrac><mn>1</mn><mrow><mn>2</mn><mo>(</mo><msub><mi>n</mi><mi>V</mi></msub><mo>−</mo><mn>1</mn><mo>)</mo></mrow></mfrac></mrow></math></span>, where <span><math><msub><mi>n</mi><mi>V</mi></msub></math></span> is the number of valence quarks in the cluster embedded in the strongly interacting environment of the hadron. The existence of such a limit imposes a new constraint on choosing the starting resolution scale <span><math><msub><mi>Q</mi><mn>0</mn></msub></math></span> for PDFs. Our prediction for the nucleon is that <span><math><mrow><msub><mi>x</mi><mi>p</mi></msub><msub><mo>∣</mo><mrow><mi>Q</mi><mo>→</mo><msub><mi>Q</mi><mn>0</mn></msub></mrow></msub><mo>≤</mo><mfrac><mn>1</mn><mn>4</mn></mfrac></mrow></math></span>, which is in agreement with all the available valence PDFs that employ the standard approach for selecting starting <span><math><msub><mi>Q</mi><mn>0</mn></msub></math></span>. We also demonstrate how the existence of this limit can be used to verify the onset of quark-cluster structures in short range nucleon correlations in nuclei.</div></div>\",\"PeriodicalId\":19246,\"journal\":{\"name\":\"Nuclear Physics A\",\"volume\":\"1064 \",\"pages\":\"Article 123243\"},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2025-09-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nuclear Physics A\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0375947425002295\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSICS, NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Physics A","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0375947425002295","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, NUCLEAR","Score":null,"Total":0}
Possible universal limit for valence parton distributions
We report the observation of the existence of a possible universal limit for valence parton distributions that should exist once partonic degrees of freedom are relevant for high energy scattering from strongly interacting bound systems like a nucleon, meson or a few nucleon system at very short distances. Our observation is based on the notion that the Bjorken x weighted valence parton distribution function has a peak, , that characterizes the average momentum fraction carried out by the valence quarks in the system. Within the residual mean-field model of the valence quark distribution we found that has an upper limit: , where is the number of valence quarks in the cluster embedded in the strongly interacting environment of the hadron. The existence of such a limit imposes a new constraint on choosing the starting resolution scale for PDFs. Our prediction for the nucleon is that , which is in agreement with all the available valence PDFs that employ the standard approach for selecting starting . We also demonstrate how the existence of this limit can be used to verify the onset of quark-cluster structures in short range nucleon correlations in nuclei.
期刊介绍:
Nuclear Physics A focuses on the domain of nuclear and hadronic physics and includes the following subsections: Nuclear Structure and Dynamics; Intermediate and High Energy Heavy Ion Physics; Hadronic Physics; Electromagnetic and Weak Interactions; Nuclear Astrophysics. The emphasis is on original research papers. A number of carefully selected and reviewed conference proceedings are published as an integral part of the journal.