Pub Date : 2024-11-12DOI: 10.1016/j.nuclphysbps.2024.11.001
Liming Zhang
The most recent LHCb results related to heavy hadron spectroscopy, encompassing both conventional and exotic states, have been reported. These results include the first observation the radiative decay , the observation of resonances in a new production environment, observation of new charmonium(-like) states in systems, and several pentaquark-related searches.
{"title":"Recent results on hadron spectroscopy at LHCb","authors":"Liming Zhang","doi":"10.1016/j.nuclphysbps.2024.11.001","DOIUrl":"10.1016/j.nuclphysbps.2024.11.001","url":null,"abstract":"<div><div>The most recent LHCb results related to heavy hadron spectroscopy, encompassing both conventional and exotic states, have been reported. These results include the first observation the radiative decay <span><math><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo>(</mo><mn>3872</mn><mo>)</mo><mo>→</mo><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo><mi>γ</mi></math></span>, the observation of <span><math><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>ϕ</mi></math></span> resonances in a new production environment, observation of new charmonium(-like) states in <span><math><msup><mrow><mi>D</mi></mrow><mrow><mo>⁎</mo><mo>±</mo></mrow></msup><msup><mrow><mi>D</mi></mrow><mrow><mo>∓</mo></mrow></msup></math></span> systems, and several pentaquark-related searches.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 90-93"},"PeriodicalIF":0.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658790","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}
Pub Date : 2024-10-28DOI: 10.1016/j.nuclphysbps.2024.10.006
Antonina Maj
We consider four-dimensional non-Abelian gauge theory living on a complex projective space as a way of gaining insights into (3+1)-dimensional QCD. In particular, we use a complex parametrization of gauge fields on which gauge transformations act homogeneously. This allows us to factor out the gauge degrees of freedom from the volume element leading to a manifestly gauge-invariant measure for the gauge-orbit space (the space of all gauge potentials modulo gauge transformations). The terms appearing in the measure that are of particular interest are mass-like terms for the gauge-invariant modes of the gauge fields. Since these mass terms come with dimensional parameters they are significant in the context of dimensional transmutation. Moreover, the existence of local gauge-invariant mass terms on could be related to Schwinger-Dyson calculations of the soft gluon mass. Finally, we argue that there is a kinematic regime in which the theory can be approximated by a 4d Wess-Zumino-Witten (WZW) theory. This result can be used to draw similarities between the mechanism of confinement in four and (2+1) dimensions.
{"title":"A gauge-invariant measure for gauge fields on CP2","authors":"Antonina Maj","doi":"10.1016/j.nuclphysbps.2024.10.006","DOIUrl":"10.1016/j.nuclphysbps.2024.10.006","url":null,"abstract":"<div><div>We consider four-dimensional non-Abelian gauge theory living on a complex projective space <span><math><msup><mrow><mi>CP</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> as a way of gaining insights into (3+1)-dimensional QCD. In particular, we use a complex parametrization of gauge fields on which gauge transformations act homogeneously. This allows us to factor out the gauge degrees of freedom from the volume element leading to a manifestly gauge-invariant measure for the gauge-orbit space (the space of all gauge potentials modulo gauge transformations). The terms appearing in the measure that are of particular interest are mass-like terms for the gauge-invariant modes of the gauge fields. Since these mass terms come with dimensional parameters they are significant in the context of dimensional transmutation. Moreover, the existence of local gauge-invariant mass terms on <span><math><msup><mrow><mi>CP</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> could be related to Schwinger-Dyson calculations of the soft gluon mass. Finally, we argue that there is a kinematic regime in which the theory can be approximated by a 4d Wess-Zumino-Witten (WZW) theory. This result can be used to draw similarities between the mechanism of confinement in four and (2+1) dimensions.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 62-67"},"PeriodicalIF":0.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554621","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}
Pub Date : 2024-10-28DOI: 10.1016/j.nuclphysbps.2024.10.008
Luca Quaglia, ALICE collaboration
The ALICE experiment at the CERN Large Hadron Collider (LHC) is a multi-purpose particle detector, mainly focused on the study of quark-gluon plasma (QGP) in heavy-ion collisions. In the forward rapidity region, 2.5 < y < 4, ALICE is equipped with a muon spectrometer (MS), which allows to study quarkonia and open heavy-flavor particles, both key probes to investigate QGP properties.
Although in LHC Run 1 and 2 many important results were achieved, the front absorber of the MS represented a limit to the physics program, due to the multiple scattering and energy loss in the material. To assess this limitation, a new forward vertex tracker (Muon Forward Tracker, MFT) was installed between the inner tracking system (ITS) and the front absorber. This has enhanced the MS physics performance, enabling the separation of prompt/non-prompt charmonium production at forward rapidity. It will also allow one to reduce the combinatorial background from semi-leptonic decays of kaons and pions. Finally, it will greatly improve the invariant-mass resolution of the low-mass dimuon pairs.
Moreover, during the ongoing LHC Run 3, the rate of Pb–Pb collisions has been increased from 10 kHz (in Run 2) up to 50 kHz, allowing to collect a data sample about 5 times larger than the one recorded in Run 2.
This contribution will provide a brief overview of the MS upgrades and it will focus on the expected physics performance during the LHC Run 3. Some of the preliminary results already obtained will also be shown.
欧洲核子研究中心（CERN）大型强子对撞机（LHC）上的 ALICE 实验是一个多用途粒子探测器，主要用于研究重离子对撞中的夸克-胶子等离子体（QGP）。在2.5 < y < 4的正向快速区，ALICE配备了一个μ介子分光计（MS），可以研究夸克态和开放重味粒子，这两种粒子都是研究QGP特性的关键探测器。虽然在LHC运行1和2中取得了许多重要成果，但由于材料中的多重散射和能量损失，MS的前吸收器对物理项目构成了限制。为了评估这一限制，在内部跟踪系统（ITS）和前吸收器之间安装了一个新的前顶点跟踪器（Muon Forward Tracker，MFT）。这增强了 MS 的物理性能，使其能够在前向速度下分离迅速/非迅速粲的产生。它还可以减少来自高子和小离子半轻子衰变的组合背景。此外，在正在进行的大型强子对撞机运行 3 期间，Pb-Pb 对撞的速率已经从运行 2 期间的 10 kHz 提高到了 50 kHz，从而可以收集到比运行 2 期间大 5 倍的数据样本。
{"title":"Recent results and upgrade of the ALICE muon spectrometer","authors":"Luca Quaglia, ALICE collaboration","doi":"10.1016/j.nuclphysbps.2024.10.008","DOIUrl":"10.1016/j.nuclphysbps.2024.10.008","url":null,"abstract":"<div><div>The ALICE experiment at the CERN Large Hadron Collider (LHC) is a multi-purpose particle detector, mainly focused on the study of quark-gluon plasma (QGP) in heavy-ion collisions. In the forward rapidity region, 2.5 < y < 4, ALICE is equipped with a muon spectrometer (MS), which allows to study quarkonia and open heavy-flavor particles, both key probes to investigate QGP properties.</div><div>Although in LHC Run 1 and 2 many important results were achieved, the front absorber of the MS represented a limit to the physics program, due to the multiple scattering and energy loss in the material. To assess this limitation, a new forward vertex tracker (Muon Forward Tracker, MFT) was installed between the inner tracking system (ITS) and the front absorber. This has enhanced the MS physics performance, enabling the separation of prompt/non-prompt charmonium production at forward rapidity. It will also allow one to reduce the combinatorial background from semi-leptonic decays of kaons and pions. Finally, it will greatly improve the invariant-mass resolution of the low-mass dimuon pairs.</div><div>Moreover, during the ongoing LHC Run 3, the rate of Pb–Pb collisions has been increased from 10 kHz (in Run 2) up to 50 kHz, allowing to collect a data sample about 5 times larger than the one recorded in Run 2.</div><div>This contribution will provide a brief overview of the MS upgrades and it will focus on the expected physics performance during the LHC Run 3. Some of the preliminary results already obtained will also be shown.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 75-81"},"PeriodicalIF":0.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.nuclphysbps.2024.10.007
Mikhail Shifman
I review the status of “good diquarks” in light-quark hadronic structure and argue that the heavy-light diquarks play no role in the structure of b-containing hadrons (including exotics), and their role in c-containing hadrons is likely to be minimal if at all. I explain that a crucial phenomenological proof can be obtained from weak decays of b-containing hadrons, such .
{"title":"QCD chemistry: Remarks on diquarks","authors":"Mikhail Shifman","doi":"10.1016/j.nuclphysbps.2024.10.007","DOIUrl":"10.1016/j.nuclphysbps.2024.10.007","url":null,"abstract":"<div><div>I review the status of “good diquarks” in light-quark hadronic structure and argue that the heavy-light diquarks play no role in the structure of <em>b</em>-containing hadrons (including exotics), and their role in <em>c</em>-containing hadrons is likely to be minimal if at all. I explain that a crucial phenomenological proof can be obtained from weak decays of <em>b</em>-containing hadrons, such <span><math><msub><mrow><mi>Λ</mi></mrow><mrow><mi>b</mi></mrow></msub></math></span>.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 86-89"},"PeriodicalIF":0.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577777","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}
Pub Date : 2024-10-28DOI: 10.1016/j.nuclphysbps.2024.10.005
M. Loewe , R. Cádiz , R. Zamora
In the frame of the linear sigma model and working in the weak field approximation, we discuss the role played by an external electric field on the behavior of π-π scattering lengths. For this purpose, we have considered all relevant one-loop diagrams in the s, t, and u channels where we have Schwinger propagators for charged pions. An important novelty of our analysis, compared with previous existing discussions in the literature, is the explicit calculation of box diagrams which were previously not considered in discussions regarding magnetic corrections to π-π scattering lengths. Our analysis shows that electric field corrections have an opposite effect with respect to the previously calculated magnetic corrections.
在线性西格玛模型和弱场近似的框架下，我们讨论了外部电场对π-π散射长度行为的作用。为此，我们考虑了 s、t 和 u 频道中所有相关的一回图，其中我们有带电小离子的施文格传播者。与之前文献中的讨论相比，我们的分析的一个重要新颖之处在于明确计算了盒图，而之前在讨论π-π散射长度的磁修正时并没有考虑到盒图。我们的分析表明，电场修正与之前计算的磁场修正具有相反的效果。
{"title":"π-π scattering lengths: Electric corrections in the linear sigma model","authors":"M. Loewe , R. Cádiz , R. Zamora","doi":"10.1016/j.nuclphysbps.2024.10.005","DOIUrl":"10.1016/j.nuclphysbps.2024.10.005","url":null,"abstract":"<div><div>In the frame of the linear sigma model and working in the weak field approximation, we discuss the role played by an external electric field on the behavior of <em>π</em>-<em>π</em> scattering lengths. For this purpose, we have considered all relevant one-loop diagrams in the <em>s</em>, <em>t</em>, and <em>u</em> channels where we have Schwinger propagators for charged pions. An important novelty of our analysis, compared with previous existing discussions in the literature, is the explicit calculation of box diagrams which were previously not considered in discussions regarding magnetic corrections to <em>π</em>-<em>π</em> scattering lengths. Our analysis shows that electric field corrections have an opposite effect with respect to the previously calculated magnetic corrections.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 82-85"},"PeriodicalIF":0.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554624","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}
Pub Date : 2024-10-18DOI: 10.1016/j.nuclphysbps.2024.10.004
R.M. Albuquerque , S. Narison , D. Rabetiarivony
We review our results on light scalar quarkonia ( and four-quark states) from (inverse) QCD Laplace sum rules (LSR) and their ratios within stability criteria and including higher order perturbative (PT) corrections up to the (estimated) . As the Operator Product Expansion (OPE) usually converges for , we evaluated the QCD spectral functions at Lowest Order (LO) of PT QCD and up to the dimension vaccum condensates. We request that the optimal results obey the constraint: Pole (Resonance) contribution to the spectral integral is larger than the QCD continuum one which excludes an on-shell mass around obtained for values of the QCD continuum threshold . Our results for the different assignments of the scalar mesons are compiled in Tables 1 to 3.
{"title":"Light scalar quarkonia from Laplace sum rule at NLO","authors":"R.M. Albuquerque , S. Narison , D. Rabetiarivony","doi":"10.1016/j.nuclphysbps.2024.10.004","DOIUrl":"10.1016/j.nuclphysbps.2024.10.004","url":null,"abstract":"<div><div>We review our results on light scalar quarkonia (<span><math><mover><mrow><mi>q</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>q</mi></math></span> and four-quark states) from (inverse) QCD Laplace sum rules (LSR) and their ratios <span><math><mi>R</mi></math></span> within stability criteria and including higher order perturbative (PT) corrections up to the (estimated) <span><math><mi>O</mi><mo>(</mo><msubsup><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow><mrow><mn>5</mn></mrow></msubsup><mo>)</mo></math></span>. As the Operator Product Expansion (OPE) usually converges for <span><math><mi>D</mi><mo>⩽</mo><mn>6</mn><mo>−</mo><mn>8</mn></math></span>, we evaluated the QCD spectral functions at Lowest Order (LO) of PT QCD and up to the <span><math><mi>D</mi><mo>=</mo><mn>6</mn></math></span> dimension vaccum condensates. We request that the optimal results obey the constraint: Pole (Resonance) contribution to the spectral integral is larger than the QCD continuum one which excludes an on-shell mass around <span><math><mo>(</mo><mn>500</mn><mo>−</mo><mn>600</mn><mo>)</mo><mspace></mspace><mtext>MeV</mtext></math></span> obtained for values of the QCD continuum threshold <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>⩽</mo><mo>(</mo><mn>1</mn><mo>∼</mo><mn>1.5</mn><mo>)</mo><mspace></mspace><msup><mrow><mtext>GeV</mtext></mrow><mrow><mn>2</mn></mrow></msup></math></span>. Our results for the different assignments of the scalar mesons are compiled in Tables 1 to 3.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 68-74"},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554622","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}
Pub Date : 2024-10-18DOI: 10.1016/j.nuclphysbps.2024.10.003
Kristina Mihule, ATLAS Collaboration
Many theories beyond the Standard Model (SM) have been proposed to address several SM shortcomings, such as explaining why the Higgs boson is so light, the origin of neutrino masses, or the observed pattern of masses and mixing angles in the quark and lepton sectors. These beyond-the-SM extensions predict new particles or interactions directly accessible at the LHC. These proceedings will highlight recent searches based on the full Run 2 data collected by the ATLAS detector at the LHC with a centre-of-mass energy of 13 TeV.
{"title":"Exotics searches at ATLAS","authors":"Kristina Mihule, ATLAS Collaboration","doi":"10.1016/j.nuclphysbps.2024.10.003","DOIUrl":"10.1016/j.nuclphysbps.2024.10.003","url":null,"abstract":"<div><div>Many theories beyond the Standard Model (SM) have been proposed to address several SM shortcomings, such as explaining why the Higgs boson is so light, the origin of neutrino masses, or the observed pattern of masses and mixing angles in the quark and lepton sectors. These beyond-the-SM extensions predict new particles or interactions directly accessible at the LHC. These proceedings will highlight recent searches based on the full Run 2 data collected by the ATLAS detector at the LHC with a centre-of-mass energy of 13 TeV.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 43-51"},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526638","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}
Pub Date : 2024-10-18DOI: 10.1016/j.nuclphysbps.2024.10.002
Yubo Han, BELLE and BELLE II Collaborations
The BELLE experiment at the KEKB collider in Tsukuba operated as a B-factory until 2018, making significant contributions to flavor physics. Building on this legacy, the BELLE II experiment, an upgraded version, now operates at the SuperKEKB energy-asymmetric collider. BELLE II has collected of data, including at the resonance. A wide range of physics topics can be studies with this data. In this proceeding, we review our latest results, which include tests of lepton flavor universality, Cabibbo-Kobayashi-Maskawa physics, searches for rare B-meson decays, and spectroscopy studies. We also discuss contributions to the prediction.
筑波 KEKB 对撞机上的 BELLE 实验作为 B 工厂一直运行到 2018 年，为味物理学做出了重大贡献。在此基础上，BELLE II 实验（升级版）目前在超级 KEKB 能量不对称 e+e 对撞机上运行。BELLE II 已经收集了 424fb-1 的数据，包括在ϒ(4S)共振处收集的 365fb-1 数据。利用这些数据可以研究广泛的物理学课题。在本论文中，我们回顾了我们的最新成果，其中包括轻子味道普遍性的检验、卡比布-小林-马斯卡瓦物理学、稀有B介子衰变的搜索以及光谱学研究。我们还讨论了对 gμ-2 预测的贡献。
{"title":"Recent highlights from the BELLE and BELLE II experiments","authors":"Yubo Han, BELLE and BELLE II Collaborations","doi":"10.1016/j.nuclphysbps.2024.10.002","DOIUrl":"10.1016/j.nuclphysbps.2024.10.002","url":null,"abstract":"<div><div>The BELLE experiment at the KEKB collider in Tsukuba operated as a B-factory until 2018, making significant contributions to flavor physics. Building on this legacy, the BELLE II experiment, an upgraded version, now operates at the SuperKEKB energy-asymmetric <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> collider. BELLE II has collected <span><math><mn>424</mn><mspace></mspace><msup><mrow><mtext>fb</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> of data, including <span><math><mn>365</mn><mspace></mspace><msup><mrow><mtext>fb</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> at the <span><math><mi>ϒ</mi><mo>(</mo><mn>4</mn><mi>S</mi><mo>)</mo></math></span> resonance. A wide range of physics topics can be studies with this data. In this proceeding, we review our latest results, which include tests of lepton flavor universality, Cabibbo-Kobayashi-Maskawa physics, searches for rare <em>B</em>-meson decays, and spectroscopy studies. We also discuss contributions to the <span><math><msub><mrow><mi>g</mi></mrow><mrow><mi>μ</mi></mrow></msub><mo>−</mo><mn>2</mn></math></span> prediction.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 52-61"},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530912","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 evaluate the Bjorken polarised sum rule (BSR) with truncated Operator Product Expansion (OPE) up to the dimension terms; the leading-twist () contribution is evaluated with a renormalon motivated resummation, where we use the IR-finite running coupling free of Landau singularities. The free residue parameters at the and terms are then extracted by fits to the experimental BSR data. In comparison to the case when perturbative QCD coupling is used in this approach (cf. Refs. [1], [2]), many advantages become manifest in the present case: (a) no regularisation in the resummation integral is needed; (b) the -interval in the fit can be significantly extended to lower -values; (c) the extracted residue parameter values are more stable, this being reflected in the significantly reduced experimental uncertainties of these values and the suppressed (almost negligible) central extracted value of the residue parameter ().
{"title":"Bjorken polarised sum rule with IR-finite QCD coupling","authors":"César Ayala , Camilo Castro-Arriaza , Gorazd Cvetič","doi":"10.1016/j.nuclphysbps.2024.09.003","DOIUrl":"10.1016/j.nuclphysbps.2024.09.003","url":null,"abstract":"<div><div>We evaluate the Bjorken polarised sum rule (BSR) <span><math><msubsup><mrow><mover><mrow><mi>Γ</mi></mrow><mo>‾</mo></mover></mrow><mrow><mn>1</mn></mrow><mrow><mi>p</mi><mo>−</mo><mi>n</mi></mrow></msubsup><mo>(</mo><msup><mrow><mi>Q</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span> with truncated Operator Product Expansion (OPE) up to the dimension <span><math><mi>D</mi><mo>=</mo><mn>4</mn></math></span> terms; the leading-twist (<span><math><mi>D</mi><mo>=</mo><mn>0</mn></math></span>) contribution is evaluated with a renormalon motivated resummation, where we use the IR-finite running coupling free of Landau singularities. The free residue parameters at the <span><math><mi>D</mi><mo>=</mo><mn>2</mn></math></span> and <span><math><mi>D</mi><mo>=</mo><mn>4</mn></math></span> terms are then extracted by fits to the experimental BSR data. In comparison to the case when perturbative QCD coupling is used in this approach (cf. Refs. <span><span>[1]</span></span>, <span><span>[2]</span></span>), many advantages become manifest in the present case: (a) no regularisation in the resummation integral is needed; (b) the <span><math><msup><mrow><mi>Q</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-interval in the fit can be significantly extended to lower <span><math><msup><mrow><mi>Q</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-values; (c) the extracted residue parameter values are more stable, this being reflected in the significantly reduced experimental uncertainties of these values and the suppressed (almost negligible) central extracted value of the <span><math><mi>D</mi><mo>=</mo><mn>4</mn></math></span> residue parameter (<span><math><msub><mrow><mi>μ</mi></mrow><mrow><mn>6</mn></mrow></msub></math></span>).</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 32-36"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434016","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}
Pub Date : 2024-10-08DOI: 10.1016/j.nuclphysbps.2024.10.001
J.J. Gálvez-Viruet
Quantum computers are promising tools for the simulation of many-body systems, and among those, QCD stands out by its rich phenomenology. Every simulation starts with a codification, and here we succently review a newly developed compact encoding based on the identification between registers and particles; the quantum memory is divided into registers, and to each we associate a Hilbert space of dimension the number of degrees of freedom of the codified particles. In this way we gain an exponential compression over direct encodings for a low number of particles with many degrees of freedom. As an example we apply this encoding on a two-register memory and implement antisymmetrization and exponentiation algorithms.
{"title":"Towards few-body QCD on a quantum computer","authors":"J.J. Gálvez-Viruet","doi":"10.1016/j.nuclphysbps.2024.10.001","DOIUrl":"10.1016/j.nuclphysbps.2024.10.001","url":null,"abstract":"<div><div>Quantum computers are promising tools for the simulation of many-body systems, and among those, QCD stands out by its rich phenomenology. Every simulation starts with a codification, and here we succently review a newly developed compact encoding based on the identification between registers and particles; the quantum memory is divided into registers, and to each we associate a Hilbert space of dimension the number of degrees of freedom of the codified particles. In this way we gain an exponential compression over direct encodings for a low number of particles with many degrees of freedom. As an example we apply this encoding on a two-register memory and implement antisymmetrization and exponentiation algorithms.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 37-42"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号