Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad1cda
Zhe Li, Kenny C. Y. Ng, Songzhan Chen, Yuncheng Nan, Huihai He
Cosmic rays can interact with the solar atmosphere and produce a slew of secondary messengers, making the Sun a bright gamma-ray source in the sky. Detailed observations with Fermi-LAT have shown that these interactions must be strongly affected by solar magnetic fields in order to produce a wide range of observational features, such as a high flux and hard spectrum. However, the detailed mechanisms behind these features are still a mystery. In this study, we tackle this problem by performing particle-interaction simulations in the solar atmosphere in the presence of coronal magnetic fields using the potential field source surface (PFSS) model. We find that low-energy (~ GeV) gamma-ray production is significantly enhanced by the coronal magnetic fields, but the enhancement decreases rapidly with energy. The enhancement directly correlates with the production of gamma rays with large deviation angles relative to the input cosmic-ray direction. We conclude that coronal magnetic fields are essential for correctly modeling solar disk gamma rays below 10 GeV, but above that, the effect of coronal magnetic fields diminishes. Other magnetic field structures are needed to explain the high-energy disk emission.
{"title":"Simulating gamma-ray production from cosmic rays interacting with the solar atmosphere in the presence of coronal magnetic fields* * Supported in China by the NSFC (12261160362, 12022502). KCYN is supported by grants provided by the NSFC (12322517, N_CUHK456/22) and RGC (24302721, 14305822, 14308023)","authors":"Zhe Li, Kenny C. Y. Ng, Songzhan Chen, Yuncheng Nan, Huihai He","doi":"10.1088/1674-1137/ad1cda","DOIUrl":"https://doi.org/10.1088/1674-1137/ad1cda","url":null,"abstract":"Cosmic rays can interact with the solar atmosphere and produce a slew of secondary messengers, making the Sun a bright gamma-ray source in the sky. Detailed observations with Fermi-LAT have shown that these interactions must be strongly affected by solar magnetic fields in order to produce a wide range of observational features, such as a high flux and hard spectrum. However, the detailed mechanisms behind these features are still a mystery. In this study, we tackle this problem by performing particle-interaction simulations in the solar atmosphere in the presence of coronal magnetic fields using the potential field source surface (PFSS) model. We find that low-energy (~ GeV) gamma-ray production is significantly enhanced by the coronal magnetic fields, but the enhancement decreases rapidly with energy. The enhancement directly correlates with the production of gamma rays with large deviation angles relative to the input cosmic-ray direction. We conclude that coronal magnetic fields are essential for correctly modeling solar disk gamma rays below 10 GeV, but above that, the effect of coronal magnetic fields diminishes. Other magnetic field structures are needed to explain the high-energy disk emission.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"350 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140310889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glitches represent a category of non-Gaussian and transient noise that frequently intersects with gravitational wave (GW) signals, thereby exerting a notable impact on the processing of GW data. The inference of GW parameters, crucial for GW astronomy research, is particularly susceptible to such interference. In this study, we pioneer the utilization of a temporal and time-spectral fusion normalizing flow for likelihood-free inference of GW parameters, seamlessly integrating the high temporal resolution of the time domain with the frequency separation characteristics of both time and frequency domains. Remarkably, our findings indicate that the accuracy of this inference method is comparable to that of traditional non-glitch sampling techniques. Furthermore, our approach exhibits a greater efficiency, boasting processing times on the order of milliseconds. In conclusion, the application of a normalizing flow emerges as pivotal in handling GW signals affected by transient noises, offering a promising avenue for enhancing the field of GW astronomy research.
{"title":"Efficient parameter inference for gravitational wave signals in the presence of transient noises using temporal and time-spectral fusion normalizing flow* * Supported by the National SKA Program of China (2022SKA0110200, 2022SKA0110203), the National Natural Science Foundation of China (11975072, 11875102, 11835009), and the National 111 Project (B16009)","authors":"Tian-Yang Sun, Chun-Yu Xiong, Shang-Jie Jin, Yu-Xin Wang, Jing-Fei Zhang, Xin Zhang","doi":"10.1088/1674-1137/ad2a5f","DOIUrl":"https://doi.org/10.1088/1674-1137/ad2a5f","url":null,"abstract":"Glitches represent a category of non-Gaussian and transient noise that frequently intersects with gravitational wave (GW) signals, thereby exerting a notable impact on the processing of GW data. The inference of GW parameters, crucial for GW astronomy research, is particularly susceptible to such interference. In this study, we pioneer the utilization of a temporal and time-spectral fusion normalizing flow for likelihood-free inference of GW parameters, seamlessly integrating the high temporal resolution of the time domain with the frequency separation characteristics of both time and frequency domains. Remarkably, our findings indicate that the accuracy of this inference method is comparable to that of traditional non-glitch sampling techniques. Furthermore, our approach exhibits a greater efficiency, boasting processing times on the order of milliseconds. In conclusion, the application of a normalizing flow emerges as pivotal in handling GW signals affected by transient noises, offering a promising avenue for enhancing the field of GW astronomy research.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"20 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad243e
Jin Ma, Sheng-Quan Wang, Ting Sun, Jian-Ming Shen, Xing-Gang Wu
In this study, we reanalyze the top-quark pair production at next-to-next-to-leading order (NNLO) in quantum chromodynamics (QCD) at future <inline-formula> <tex-math><?CDATA $ e^+e^- $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M2.jpg" xlink:type="simple"></inline-graphic> </inline-formula> colliders using the Principle of Maximum Conformality (PMC) method. The PMC renormalization scales in <inline-formula> <tex-math><?CDATA $ alpha_s $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M3.jpg" xlink:type="simple"></inline-graphic> </inline-formula> are determined by absorbing the non-conformal <italic toggle="yes">β</italic> terms by recursively using the Renormalization Group Equation (RGE). Unlike the conventional scale-setting method of fixing the scale at the center-of-mass energy <inline-formula> <tex-math><?CDATA $ mu_r=sqrt{s} $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M4.jpg" xlink:type="simple"></inline-graphic> </inline-formula>, the determined PMC scale <inline-formula> <tex-math><?CDATA $ Q_star $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M5.jpg" xlink:type="simple"></inline-graphic> </inline-formula> is far smaller than the <inline-formula> <tex-math><?CDATA $ sqrt{s} $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M6.jpg" xlink:type="simple"></inline-graphic> </inline-formula> and increases with the <inline-formula> <tex-math><?CDATA $ sqrt{s} $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M7.jpg" xlink:type="simple"></inline-graphic> </inline-formula>, yielding the correct physical behavior for the top-quark pair production process. Moreover, the convergence of the pQCD series for the top-quark pair production is greatly improved owing to the elimination of the renormalon divergence. For a typical collision energy of <inline-formula> <tex-math><?CDATA $ sqrt{s}=500 $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M8.jpg" xlink:type="simple"></inline-graphic> </inline-formula> GeV, the PMC scale is <inline-formula> <tex-math><?CDATA $ Q_star=107 $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M9.jpg" xlink:type="simple"></inline-graphic> </inline-formula> GeV; the QCD correction factor <italic toggle="yes">K</italic> for conventional results is <inline-formula> <tex-math><?CDATA $ Ksim1+0.1244^{+0.0102+0.0012}_{-0.0087-0.0011}+0.0184^{-0.0086+0.0002}_{+0.0061-0.0003} $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M10.jpg" xlink:type="simple"></inline-graphic> </inline-formula>, where the first error is caused by varying the scale <inline-formula> <tex-math><?CDATA $ mu_rin[sqrt{s}/2, 2sqrt{s}] $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M11.jpg" xlink:type="simple"></inline-graphic> </inline-formula> and the second error is from the top-quark mass <inline-formula> <tex-math><?CDATA $ Delta{m_t}=pm0.7 $?></tex-math> <inline-graphic xlink:href="cpc_48_4_043105_M12.jpg" xlink:type="simple"></inline-graphic> </inli
在本研究中，我们利用最大共形原理（PMC）方法，在未来对撞机上重新分析了量子色动力学（QCD）中次前阶（NNLO）的顶夸克对产生。PMC中的重正化尺度是通过递归使用重正化群方程（Renormalization Group Equation，RGE）吸收非共形β项来确定的。与将尺度固定在质量中心能量上的传统尺度设定方法不同，所确定的 PMC 尺度远远小于 ，并随着 ，的增大而增大，从而产生了正确的顶夸克对产生过程的物理行为。此外，由于消除了重正子发散，pQCD 序列对顶夸克对产生的收敛性大大提高。对于 GeV 的典型对撞能量，PMC 尺度为 GeV；传统结果的 QCD 修正系数 K 为 ，其中第一个误差由尺度变化引起，第二个误差来自顶夸克质量 GeV。应用 PMC 后，消除了重正化尺度的不确定性，QCD 修正系数 K 提高到 ，其中误差来自顶夸克质量 GeV。PMC对顶夸克对产生的改进预测有助于在未来对撞机上详细研究顶夸克的性质。
{"title":"Revisiting the top-quark pair production at future e + e − colliders* * Supported in part by the Natural Science Foundation of China (12175025, 12147102, 12265011), by the Projects of Guizhou Provincial Department (YQK[2023]016, ZK[2023]141, [2020]1Y027, GZMUZK[2022]PT01)","authors":"Jin Ma, Sheng-Quan Wang, Ting Sun, Jian-Ming Shen, Xing-Gang Wu","doi":"10.1088/1674-1137/ad243e","DOIUrl":"https://doi.org/10.1088/1674-1137/ad243e","url":null,"abstract":"In this study, we reanalyze the top-quark pair production at next-to-next-to-leading order (NNLO) in quantum chromodynamics (QCD) at future <inline-formula>\u0000<tex-math><?CDATA $ e^+e^- $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M2.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> colliders using the Principle of Maximum Conformality (PMC) method. The PMC renormalization scales in <inline-formula>\u0000<tex-math><?CDATA $ alpha_s $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M3.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> are determined by absorbing the non-conformal <italic toggle=\"yes\">β</italic> terms by recursively using the Renormalization Group Equation (RGE). Unlike the conventional scale-setting method of fixing the scale at the center-of-mass energy <inline-formula>\u0000<tex-math><?CDATA $ mu_r=sqrt{s} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M4.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, the determined PMC scale <inline-formula>\u0000<tex-math><?CDATA $ Q_star $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M5.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> is far smaller than the <inline-formula>\u0000<tex-math><?CDATA $ sqrt{s} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M6.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and increases with the <inline-formula>\u0000<tex-math><?CDATA $ sqrt{s} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M7.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, yielding the correct physical behavior for the top-quark pair production process. Moreover, the convergence of the pQCD series for the top-quark pair production is greatly improved owing to the elimination of the renormalon divergence. For a typical collision energy of <inline-formula>\u0000<tex-math><?CDATA $ sqrt{s}=500 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M8.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> GeV, the PMC scale is <inline-formula>\u0000<tex-math><?CDATA $ Q_star=107 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M9.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> GeV; the QCD correction factor <italic toggle=\"yes\">K</italic> for conventional results is <inline-formula>\u0000<tex-math><?CDATA $ Ksim1+0.1244^{+0.0102+0.0012}_{-0.0087-0.0011}+0.0184^{-0.0086+0.0002}_{+0.0061-0.0003} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M10.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, where the first error is caused by varying the scale <inline-formula>\u0000<tex-math><?CDATA $ mu_rin[sqrt{s}/2, 2sqrt{s}] $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M11.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and the second error is from the top-quark mass <inline-formula>\u0000<tex-math><?CDATA $ Delta{m_t}=pm0.7 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043105_M12.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inli","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"40 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad1dcd
Brahim Asfour, Aatifa Bargach, Ahmed Errahmani, Taoufik Ouali
In this paper, we propose a hybrid metric Palatini approach in which the Palatini scalar curvature is non minimally coupled to the scalar field. We derive Einstein's field equations, i.e., the equations of motion of the scalar field. Furthermore, the background and perturbative parameters are obtained by means of Friedmann equations in the slow roll regime. The analysis of cosmological perturbations allowed us to obtain the main inflationary parameters, e.g., the scalar spectral indexand tensor to scalar ratio r. From this perspective, as an application of our analysis, we consider the Higgs field with quartic potential, which plays the inflaton role, and show that predictions of Higgs hybrid inflation are in good agreement with recent observational data [Astron. Astrophys. 641, 61 (2020)].
{"title":"Higgs inflation model with non-minimal coupling in hybrid Palatini approach","authors":"Brahim Asfour, Aatifa Bargach, Ahmed Errahmani, Taoufik Ouali","doi":"10.1088/1674-1137/ad1dcd","DOIUrl":"https://doi.org/10.1088/1674-1137/ad1dcd","url":null,"abstract":"In this paper, we propose a hybrid metric Palatini approach in which the Palatini scalar curvature is non minimally coupled to the scalar field. We derive Einstein's field equations, i.e., the equations of motion of the scalar field. Furthermore, the background and perturbative parameters are obtained by means of Friedmann equations in the slow roll regime. The analysis of cosmological perturbations allowed us to obtain the main inflationary parameters, e.g., the scalar spectral index<inline-formula>\u0000<tex-math><?CDATA $ n_s $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_045104_M1.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>and tensor to scalar ratio <italic toggle=\"yes\">r</italic>. From this perspective, as an application of our analysis, we consider the Higgs field with quartic potential, which plays the inflaton role, and show that predictions of Higgs hybrid inflation are in good agreement with recent observational data [Astron. Astrophys. 641, 61 (2020)].","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"31 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad1a0b
Chang Chen, Ce Meng, Zhiguang Xiao, Han-Qing Zheng
Recently, the LHCb experimental group found an exotic state from the process. A key question is whether it is just a molecule or may have a confined tetraquark ingredient. To investigate this, different methods were used, including a two-channel ( and ) K-matrix unitarization and a single-channel Flatté-like parametrization method analyzed utilizing the pole counting rule and spectral density function sum rule. These analyses demonstrated that is a molecular state, although the possibility that there may exist an elementary ingredient cannot be excluded, according to an approximate analysis of its production rate.
{"title":"Some remarks on compositeness of * * Supported in part by the National Nature Science Foundations of China (12335002, 12375078, 11975028). H.Q. Zheng and Z. Xiao are also Supported by \"the Fundamental Research Funds for the Central Universities\"","authors":"Chang Chen, Ce Meng, Zhiguang Xiao, Han-Qing Zheng","doi":"10.1088/1674-1137/ad1a0b","DOIUrl":"https://doi.org/10.1088/1674-1137/ad1a0b","url":null,"abstract":"Recently, the LHCb experimental group found an exotic state <inline-formula>\u0000<tex-math><?CDATA $ T^+_{cc} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043102_M1.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> from the <inline-formula>\u0000<tex-math><?CDATA $ pp to D^0D^0pi^+ + X $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043102_M2.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> process. A key question is whether it is just a molecule or may have a confined tetraquark ingredient. To investigate this, different methods were used, including a two-channel (<inline-formula>\u0000<tex-math><?CDATA $ D^{*+}D^0 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043102_M3.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and <inline-formula>\u0000<tex-math><?CDATA $ D^{*0}D^+ $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043102_M4.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>) <italic toggle=\"yes\">K</italic>-matrix unitarization and a single-channel Flatté-like parametrization method analyzed utilizing the pole counting rule and spectral density function sum rule. These analyses demonstrated that <inline-formula>\u0000<tex-math><?CDATA $ T^+_{cc} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043102_M5.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> is a molecular state, although the possibility that there may exist an elementary ingredient cannot be excluded, according to an approximate analysis of its production rate.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"57 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad20d5
Y. Mahmoud, H. Abdallah, M. T. Hussein, S. Elgammal
In this study, we conducted a search for dark matter using a part of the data recorded by the CMS experiment during run-I of the LHC in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb−1. These data were gathered from the CMS open data. Dark matter, in the framework of the simplified model (mono-Z), can be produced from proton-proton collisions in association with a new hypothetical gauge boson, Z. Thus, the search was conducted in the dimuon plus large missing transverse momentum channel. One benchmark scenario of mono-Z, which is known as light vector, was used for interpreting the CMS open data. No evidence of dark matter was observed, and exclusion limits were set on the masses of dark matter and Z at 95% confidence level.
在这项研究中，我们利用 CMS 实验在 2012 年大型强子对撞机运行 I 期间记录的部分数据对暗物质进行了搜索，这些数据的质心能量为 8 TeV，综合光度为 11.6 fb-1。这些数据来自CMS开放数据。在简化模型（mono-Z）的框架内，暗物质可以通过质子-质子对撞与一种新的假定规玻色子Z结合产生。在解释 CMS 公开数据时，使用了一种单 Z 的基准方案，即所谓的光矢量。没有观测到暗物质的证据，因此对暗物质和Z的质量设定了置信度为95%的排除限。
{"title":"Search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at TeV using CMS open data* * Y. Mahmoud wishes to thank the Center for Theoretical Physics (CTP) at the British University in Egypt (BUE) for its continuous support, both financially and scientifically, for this work.","authors":"Y. Mahmoud, H. Abdallah, M. T. Hussein, S. Elgammal","doi":"10.1088/1674-1137/ad20d5","DOIUrl":"https://doi.org/10.1088/1674-1137/ad20d5","url":null,"abstract":"In this study, we conducted a search for dark matter using a part of the data recorded by the CMS experiment during run-I of the LHC in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb<sup>−1</sup>. These data were gathered from the CMS open data. Dark matter, in the framework of the simplified model (mono-<italic toggle=\"yes\">Z</italic>\u0000<inline-formula>\u0000<tex-math><?CDATA $ ^{prime} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043001_M3.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>), can be produced from proton-proton collisions in association with a new hypothetical gauge boson, <italic toggle=\"yes\">Z</italic>\u0000<inline-formula>\u0000<tex-math><?CDATA $ ^{prime} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043001_M4.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>. Thus, the search was conducted in the dimuon plus large missing transverse momentum channel. One benchmark scenario of mono-<italic toggle=\"yes\">Z</italic>\u0000<inline-formula>\u0000<tex-math><?CDATA $ ^{prime} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043001_M5.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, which is known as light vector, was used for interpreting the CMS open data. No evidence of dark matter was observed, and exclusion limits were set on the masses of dark matter and <italic toggle=\"yes\">Z</italic>\u0000<inline-formula>\u0000<tex-math><?CDATA $ ^{prime} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_043001_M6.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> at 95% confidence level.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"20 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad243f
Wendi Lv, Yang Li, Ziyang Li, Rongrong Ma, Zebo Tang, Prithwish Tribedy, Chun Yuen Tsang, Zhangbu Xu, Wangmei Zha
Baryon numbers are theorized to be carried by valence quarks in the standard QCD picture of the baryon structure. Another theory proposed an alternative baryon number carrier, a non-perturbative Y-shaped configuration of the gluon field, called the baryon junction in the 1970s. However, neither of these theories has been verified experimentally. Recently, searching for the baryon junction by investigating the correlation of net-charge and net-baryon yields at midrapidity in heavy-ion collisions has been suggested. This paper presents studies of such correlations in collisions of various heavy ions from oxygen to uranium with the UrQMD Monte Carlo model. The UrQMD model implements valence quark transport as the primary means of charge and baryon stopping at midrapidity. Detailed studies are also conducted for isobaric + and + collisions. We found a universal trend of charge stopping with respect to baryon stopping and discovered that the charge stopping is always greater than the baryon stopping. This study provides a model baseline in valence quark transport for what is expected in net-charge and net-baryon yields at the midrapidity of relativistic heavy-ion collisions.
{"title":"Correlations of baryon and charge stopping in heavy ion collisions* * Supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB34030000) and the National Key Research and Development Program of China (2022YFA1604900), the U.S. DOE Office of Science365 under contract (DE-SC0012704, DE-FG02-10ER41666, DE-AC02-98CH10886)","authors":"Wendi Lv, Yang Li, Ziyang Li, Rongrong Ma, Zebo Tang, Prithwish Tribedy, Chun Yuen Tsang, Zhangbu Xu, Wangmei Zha","doi":"10.1088/1674-1137/ad243f","DOIUrl":"https://doi.org/10.1088/1674-1137/ad243f","url":null,"abstract":"Baryon numbers are theorized to be carried by valence quarks in the standard QCD picture of the baryon structure. Another theory proposed an alternative baryon number carrier, a non-perturbative Y-shaped configuration of the gluon field, called the baryon junction in the 1970s. However, neither of these theories has been verified experimentally. Recently, searching for the baryon junction by investigating the correlation of net-charge and net-baryon yields at midrapidity in heavy-ion collisions has been suggested. This paper presents studies of such correlations in collisions of various heavy ions from oxygen to uranium with the UrQMD Monte Carlo model. The UrQMD model implements valence quark transport as the primary means of charge and baryon stopping at midrapidity. Detailed studies are also conducted for isobaric <inline-formula>\u0000<tex-math><?CDATA $ _{40}^{96}{rm{Zr}} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_044001_M1.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> + <inline-formula>\u0000<tex-math><?CDATA $ _{40}^{96}{rm{Zr}} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_044001_M2.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and <inline-formula>\u0000<tex-math><?CDATA $ _{44}^{96}{rm{Ru}} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_044001_M3.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> + <inline-formula>\u0000<tex-math><?CDATA $ _{44}^{96}{rm{Ru}} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_044001_M4.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> collisions. We found a universal trend of charge stopping with respect to baryon stopping and discovered that the charge stopping is always greater than the baryon stopping. This study provides a model baseline in valence quark transport for what is expected in net-charge and net-baryon yields at the midrapidity of relativistic heavy-ion collisions.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"33 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad2361
Ye Lu, Chang Chen, Guang-You Qin, Han-Qing Zheng
The attractive interaction between and has to be strong enough if X(6900) is of the molecule type. We argue that since decays predominantly into a pair, the interactions between and may be significantly enhanced owing to the three point loop diagram. The enhancement originates from the anomalous threshold located at GeV, whose effect propagates into the s-channel partial wave amplitude in the vicinity of GeV. This effect may be helpful in the formation of the peak.
如果 X(6900) 属于分子类型，那么和之间的吸引力相互作用必须足够强。我们认为，由于衰变主要是变成一对，和之间的相互作用可能会由于三点环图而显著增强。这种增强源于位于 GeV 的反常阈值，其效应会传播到 GeV 附近的 s 沟道部分波幅。这种效应可能有助于峰值的形成。
{"title":"A discussion on the anomalous threshold enhancement of – couplings and peak* * Supported in part by the National Nature Science Foundations of China (12335002). This work is also supported by the Fundamental Research Funds for the Central Universities","authors":"Ye Lu, Chang Chen, Guang-You Qin, Han-Qing Zheng","doi":"10.1088/1674-1137/ad2361","DOIUrl":"https://doi.org/10.1088/1674-1137/ad2361","url":null,"abstract":"The attractive interaction between <inline-formula>\u0000<tex-math><?CDATA $ J/psi $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M4.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and <inline-formula>\u0000<tex-math><?CDATA $ psi(3770) $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M5.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> has to be strong enough if X(6900) is of the molecule type. We argue that since <inline-formula>\u0000<tex-math><?CDATA $ psi(3770) $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M6.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> decays predominantly into a <inline-formula>\u0000<tex-math><?CDATA $ Dbar D $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M7.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> pair, the interactions between <inline-formula>\u0000<tex-math><?CDATA $ J/psi $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M8.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and <inline-formula>\u0000<tex-math><?CDATA $ psi(3770) $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M9.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> may be significantly enhanced owing to the three point <inline-formula>\u0000<tex-math><?CDATA $ Dbar D $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M10.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> loop diagram. The enhancement originates from the anomalous threshold located at <inline-formula>\u0000<tex-math><?CDATA $ t=-1.288 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M11.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> GeV<inline-formula>\u0000<tex-math><?CDATA $ ^2 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M12.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, whose effect propagates into the <italic toggle=\"yes\">s</italic>-channel partial wave amplitude in the vicinity of <inline-formula>\u0000<tex-math><?CDATA $ sqrt{s}simeq 6.94 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M13.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> GeV. This effect may be helpful in the formation of the <inline-formula>\u0000<tex-math><?CDATA $ X(6900) $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_041001_M14.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> peak.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"7 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad2360
Qi-Ming Fu, Meng-Ci He, Tao-Tao Sui, Xin Zhang
In this paper, we present several explicit reconstructions for the aether scalar tensor (AeST) theory derived from the background of the Friedmann-Lemaître-Robertson-Walker cosmological evolution. It is shown that the Einstein-Hilbert Lagrangian with a positive cosmological constant is the only Lagrangian capable of accurately replicating the exact expansion history of the Λ cold dark matter (ΛCDM) universe filled solely with dust-like matter. However, the ΛCDM-era can be produced within the framework of the AeST theory for some other fluids, including a perfect fluid with , multifluids, and nonisentropic perfect fluids. Moreover, we demonstrate that the ΛCDM-era can be replicated with no real matter field for the AeST theory. The cosmic evolution resulting from both the power-law and de-Sitter solutions can also be obtained.
{"title":"Reconstruction of aether scalar tensor theory for variouscosmological scenarios* * Supported by the National Natural Science Foundation of China (11975072, 11875102, 11835009), National SKA Program of China (2022SKA0110200, 2022SKA0110203), Shaanxi Provincial Education Department (21JK0556), and Shaanxi Provincial Department of Science and Technology (2023-JC-QN-0077)","authors":"Qi-Ming Fu, Meng-Ci He, Tao-Tao Sui, Xin Zhang","doi":"10.1088/1674-1137/ad2360","DOIUrl":"https://doi.org/10.1088/1674-1137/ad2360","url":null,"abstract":"In this paper, we present several explicit reconstructions for the aether scalar tensor (AeST) theory derived from the background of the Friedmann-Lemaître-Robertson-Walker cosmological evolution. It is shown that the Einstein-Hilbert Lagrangian with a positive cosmological constant is the only Lagrangian capable of accurately replicating the exact expansion history of the Λ cold dark matter (ΛCDM) universe filled solely with dust-like matter. However, the ΛCDM-era can be produced within the framework of the AeST theory for some other fluids, including a perfect fluid with <inline-formula>\u0000<tex-math><?CDATA $ p=-(1/3)rho $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_4_045105_M1.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, multifluids, and nonisentropic perfect fluids. Moreover, we demonstrate that the ΛCDM-era can be replicated with no real matter field for the AeST theory. The cosmic evolution resulting from both the power-law and de-Sitter solutions can also be obtained.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"32 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1088/1674-1137/ad260a
Yan Liu, Bing Sun
The study of Kerr geodesics has a long history, particularly for those occurring within the equatorial plane, which are generally well-understood. However, when compared with the classification introduced by one of the authors [Phys. Rev. D 105, 024075 (2022)], it becomes apparent that certain classes of geodesics, such as trapped orbits, still lack analytical solutions. Thus, in this study, we provide explicit analytical solutions for equatorial timelike geodesics in Kerr spacetime, including solutions of trapped orbits, which capture the characteristics of special geodesics, such as the positions and conserved quantities of circular, bound, and deflecting orbits. Specifically, we determine the precise location at which retrograde orbits undergo a transition from counter-rotating to prograde motion due to the strong gravitational effects near a rotating black hole. Interestingly, the trajectory remains prograde for orbits with negative energy despite the negative angular momentum. Furthermore, we investigate the intriguing phenomenon of deflecting orbits exhibiting an increased number of revolutions around the black hole as the turning point approaches the turning point of the trapped orbit. Additionally, we find that only prograde marginal deflecting geodesics are capable of traversing through the ergoregion. In summary, our findings present explicit solutions for equatorial timelike geodesics and offer insights into the dynamics of particle motion in the vicinity of a rotating black hole.
对克尔大地线的研究由来已久，尤其是对发生在赤道面内的大地线的研究，一般都能很好地理解。然而，与其中一位作者提出的分类[Phys. Rev. D 105, 024075 (2022)]相比，某些类别的大地线，如受困轨道，显然仍然缺乏解析解。因此，在本研究中，我们提供了克尔时空中赤道时间似大地线的显式解析解，包括受困轨道的解，这些解捕捉到了特殊大地线的特征，如圆轨道、束缚轨道和偏转轨道的位置和守恒量。具体来说，我们确定了逆行轨道在旋转黑洞附近的强引力作用下从逆转运动过渡到顺行运动的精确位置。有趣的是，对于具有负能量的轨道，尽管角动量为负，但其轨迹仍然是顺行的。此外，我们还研究了一个有趣的现象：当转折点接近被困轨道的转折点时，偏转轨道绕黑洞旋转的圈数增加。此外，我们还发现，只有顺行边缘偏转大地线能够穿越厄尔戈里区。总之，我们的研究结果提出了赤道时间似大地线的显式解，并提供了对旋转黑洞附近粒子运动动力学的见解。
{"title":"Analytical solutions of equatorial geodesic motion in Kerr spacetime* * Y. L. is financially supported by the Natural Science Foundation of Shandong Province (ZR2023QA133) and Yantai University (WL22B218). B.S. is Supported by the National Natural Science Foundation of China (12375046) and Beijing University of Agriculture (QJKC-2023032).","authors":"Yan Liu, Bing Sun","doi":"10.1088/1674-1137/ad260a","DOIUrl":"https://doi.org/10.1088/1674-1137/ad260a","url":null,"abstract":"The study of Kerr geodesics has a long history, particularly for those occurring within the equatorial plane, which are generally well-understood. However, when compared with the classification introduced by one of the authors [Phys. Rev. D 105, 024075 (2022)], it becomes apparent that certain classes of geodesics, such as trapped orbits, still lack analytical solutions. Thus, in this study, we provide explicit analytical solutions for equatorial timelike geodesics in Kerr spacetime, including solutions of trapped orbits, which capture the characteristics of special geodesics, such as the positions and conserved quantities of circular, bound, and deflecting orbits. Specifically, we determine the precise location at which retrograde orbits undergo a transition from counter-rotating to prograde motion due to the strong gravitational effects near a rotating black hole. Interestingly, the trajectory remains prograde for orbits with negative energy despite the negative angular momentum. Furthermore, we investigate the intriguing phenomenon of deflecting orbits exhibiting an increased number of revolutions around the black hole as the turning point approaches the turning point of the trapped orbit. Additionally, we find that only prograde marginal deflecting geodesics are capable of traversing through the ergoregion. In summary, our findings present explicit solutions for equatorial timelike geodesics and offer insights into the dynamics of particle motion in the vicinity of a rotating black hole.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"31 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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