Pub Date : 2024-08-01DOI: 10.1088/1674-1137/ad53b6
Chao-Qiang Geng, Chia-Wei Liu, Jiabao Zhang
We explored a new approach to search for a low-mass particle through decays by identifying its existence through parity-violating phenomena in the isospin-violating final states of and the corresponding charge conjugated states of . Our investigation centered on a generation-independent and leptophobic with mass below 10 GeV. Given the present experimental conditions at Beijing Spectrometer III (BESIII) and the anticipated opportunities at the Super Tau Charm Factory (STCF), we conducted Monte-Carlo simulations to predict possible events at both facilities. Notably, we foresee a substantial enhancement in the precision of the lower limit estimation of as well as a reduction in statistical uncertainty with upcoming STCF experiments. Furthermore, it is essential to highlight that a null result in the measurement of would impose stringent constraints, requiring the couplings to be in the order of .
{"title":"New signature of low mass Z′ in J/ψ decays* * Supported in part by the National Key Research and Development Program of China under (2020YFC2201501) and the National Natural Science Foundation of China (NSFC) (12347103, 12205063)","authors":"Chao-Qiang Geng, Chia-Wei Liu, Jiabao Zhang","doi":"10.1088/1674-1137/ad53b6","DOIUrl":"https://doi.org/10.1088/1674-1137/ad53b6","url":null,"abstract":"We explored a new approach to search for a low-mass <inline-formula>\u0000<tex-math><?CDATA $ Z^{prime} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M3.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> particle through <inline-formula>\u0000<tex-math><?CDATA $ J/psi $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M4.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> decays by identifying its existence through parity-violating phenomena in the isospin-violating final states of <inline-formula>\u0000<tex-math><?CDATA $ Lambdaoverline{Sigma}^{0} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M5.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and the corresponding charge conjugated states of <inline-formula>\u0000<tex-math><?CDATA $ overline{Lambda}Sigma^{0} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M6.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>. Our investigation centered on a generation-independent and leptophobic <inline-formula>\u0000<tex-math><?CDATA $ Z^{prime} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M7.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> with mass below 10 GeV. Given the present experimental conditions at Beijing Spectrometer III (BESIII) and the anticipated opportunities at the Super Tau Charm Factory (STCF), we conducted Monte-Carlo simulations to predict possible events at both facilities. Notably, we foresee a substantial enhancement in the precision of the lower limit estimation of <inline-formula>\u0000<tex-math><?CDATA $ alpha_{text{NP}} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M8.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> as well as a reduction in statistical uncertainty with upcoming STCF experiments. Furthermore, it is essential to highlight that a null result in the measurement of <inline-formula>\u0000<tex-math><?CDATA $ alpha_{text{NP}} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M9.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> would impose stringent constraints, requiring the <inline-formula>\u0000<tex-math><?CDATA $ Z^{prime}-q-q $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M10.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> couplings to be in the order of <inline-formula>\u0000<tex-math><?CDATA $ 10^{-2} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_081001_M11.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"50 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566845","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}
The similar densities of dark matter and baryons in the universe imply that they may arise from the same ultraviolet model. B-Mesogenesis, which assumes dark matter is charged under the baryon number, attempts to simultaneously explain the origin of baryon asymmetry and dark matter in the universe. In particular, B-Mesogenesis may induce bottom-baryon decays into invisible or semi-invisible final states, which provide a distinctive signal for probing this scenario. In this work, we systematically study the invisible decays of bottom baryons into dark matter and the semi-invisible decays of bottom baryons into a meson or a photon together with a dark matter particle. In particular, the fully invisible decay can reveal the stable particles in B-Mesogenesis. Some QCD-based frameworks are used to calculate the hadronic matrix elements under the B-Mesogenesis model. We estimate the constraints on the Wilson coefficients or the product of some new physics couplings with the Wilson coefficients according to the semi-invisible and invisible decays of bottom baryons detectable at future colliders.
{"title":"Invisible and semi-invisible decays of bottom baryons* * The work is partly Supported by the National Key Research and Development Program of China (2020YFA0406400, 2023YFA1606000), and the National Natural Science Foundation of China (12335003, 12275277)","authors":"Yong Zheng, Jian-Nan Ding, Dong-Hao Li, Lei-Yi Li, Cai-Dian Lü, Fu-Sheng Yu","doi":"10.1088/1674-1137/ad4afa","DOIUrl":"https://doi.org/10.1088/1674-1137/ad4afa","url":null,"abstract":"The similar densities of dark matter and baryons in the universe imply that they may arise from the same ultraviolet model. <italic toggle=\"yes\">B</italic>-Mesogenesis, which assumes dark matter is charged under the baryon number, attempts to simultaneously explain the origin of baryon asymmetry and dark matter in the universe. In particular, <italic toggle=\"yes\">B</italic>-Mesogenesis may induce bottom-baryon decays into invisible or semi-invisible final states, which provide a distinctive signal for probing this scenario. In this work, we systematically study the invisible decays of bottom baryons into dark matter and the semi-invisible decays of bottom baryons into a meson or a photon together with a dark matter particle. In particular, the fully invisible decay can reveal the stable particles in <italic toggle=\"yes\">B</italic>-Mesogenesis. Some QCD-based frameworks are used to calculate the hadronic matrix elements under the <italic toggle=\"yes\">B</italic>-Mesogenesis model. We estimate the constraints on the Wilson coefficients or the product of some new physics couplings with the Wilson coefficients according to the semi-invisible and invisible decays of bottom baryons detectable at future colliders.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"44 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141577567","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 : 2024-08-01DOI: 10.1088/1674-1137/ad47a9
Zhi-Chao Wang, Xian Gao
We investigate a class of gravity theories respecting only spatial covariance, termed spatially covariant gravity, in the presence of an auxiliary scalar field. We examine the conditions on the Lagrangian required to eliminate scalar degrees of freedom, allowing only two tensorial degrees of freedom to propagate. Instead of strict constraint analysis, in this paper, we employ the perturbation method and focus on the necessary conditions to evade the scalar mode at the linear order in perturbations around a cosmological background. Beginning with a general action and solving the auxiliary perturbation variables in terms of a would-be dynamical scalar mode, we derive the condition to remove its kinetic term, thus ensuring that no scalar mode propagates. As an application of the general condition, we study a polynomial-type Lagrangian as a concrete example, in which all monomials are spatially covariant scalars containing two derivatives. We find that the auxiliary scalar field is essential, and new terms in the Lagrangian are allowed. Our analysis provides insights into constructing gravity theories with two degrees of freedom in the extended framework of spatially covariant gravity.
{"title":"Spatial covariant gravity with two degrees of freedom in the presence of an auxiliary scalar field: Perturbation analysis* * Supported by the Natural Science Foundation of China (11975020)","authors":"Zhi-Chao Wang, Xian Gao","doi":"10.1088/1674-1137/ad47a9","DOIUrl":"https://doi.org/10.1088/1674-1137/ad47a9","url":null,"abstract":"We investigate a class of gravity theories respecting only spatial covariance, termed spatially covariant gravity, in the presence of an auxiliary scalar field. We examine the conditions on the Lagrangian required to eliminate scalar degrees of freedom, allowing only two tensorial degrees of freedom to propagate. Instead of strict constraint analysis, in this paper, we employ the perturbation method and focus on the necessary conditions to evade the scalar mode at the linear order in perturbations around a cosmological background. Beginning with a general action and solving the auxiliary perturbation variables in terms of a would-be dynamical scalar mode, we derive the condition to remove its kinetic term, thus ensuring that no scalar mode propagates. As an application of the general condition, we study a polynomial-type Lagrangian as a concrete example, in which all monomials are spatially covariant scalars containing two derivatives. We find that the auxiliary scalar field is essential, and new terms in the Lagrangian are allowed. Our analysis provides insights into constructing gravity theories with two degrees of freedom in the extended framework of spatially covariant gravity.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"16 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566846","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 : 2024-08-01DOI: 10.1088/1674-1137/ad4af3
Jie Sheng, Yu Cheng, Weikang Lin, Tsutomu T. Yanagida
The féeton is the gauge boson of the gauge theory. If the gauge coupling constant is extremely small, the féeton becomes a candidate for dark matter. We show that its decay to a pair of an electron and a positron explains the observed Galactic 511-keV gamma-ray excess in a consistent manner. This féeton dark matter decays mainly into pairs neutrino and anti-neutrino. Future low-energy experiments with improved directional capability will enable capturing these neutrino signals. The seesaw-motivated parameter space predicts a relatively short féeton lifetime that is comparable to the current cosmological constraint.
{"title":"Féeton (B-L gauge boson) dark matter for the 511-keV gamma-ray excess and the prediction of low-energy neutrino flux* * Supported by the Talent Scientific Start-Up Project of China, the Natural Science Foundation of China (12175134, 12375101, 12090060, 12090064, 12247141), the SJTU Double First Class start-up fund(WF220442604), and the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan","authors":"Jie Sheng, Yu Cheng, Weikang Lin, Tsutomu T. Yanagida","doi":"10.1088/1674-1137/ad4af3","DOIUrl":"https://doi.org/10.1088/1674-1137/ad4af3","url":null,"abstract":"The féeton is the gauge boson of the <inline-formula>\u0000<tex-math><?CDATA $ U(1)_{B-L} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_083104_M1.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> gauge theory. If the gauge coupling constant is extremely small, the féeton becomes a candidate for dark matter. We show that its decay to a pair of an electron and a positron explains the observed Galactic 511-keV gamma-ray excess in a consistent manner. This féeton dark matter decays mainly into pairs neutrino and anti-neutrino. Future low-energy experiments with improved directional capability will enable capturing these neutrino signals. The seesaw-motivated parameter space predicts a relatively short féeton lifetime that is comparable to the current cosmological constraint.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"2015 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566848","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}
Heavy flavor particles provide important probes of the microscopic structure and thermodynamic properties of the quark-gluon plasma (QGP) produced in high-energy nucleus-nucleus collisions. We studied the energy loss and flow of charm and bottom quarks inside the QGP via the nuclear modification factor () and elliptic flow coefficient () of their decayed leptons in heavy-ion collisions at the LHC. The dynamical evolution of the QGP was performed using the CLVisc (3+1)-dimensional viscous hydrodynamics model; the evolution of heavy quarks inside the QGP was simulated with our improved Langevin model that considers both collisional and radiative energy loss of heavy quarks; the hadronization of heavy quarks was simulated via our hybrid coalescence-fragmentation model; and the semi-leptonic decay of D and B mesons was simulated via PYTHIA. Using the same spatial diffusion coefficient for charm and bottom quarks, we obtained smaller and larger of charm decayed leptons than bottom decayed leptons, indicating stronger energy loss of charm quarks than bottom quarks inside the QGP within our current model setup.
{"title":"Quenching and flow of charm and bottom quarks via semi-leptonic decay of D and B mesons in Pb+Pb collisions at the LHC* * Supported in part by the National Natural Science Foundation of China (12225503, 11935007, 11890710, 11890711, 12175122, 2021-867). W.-J. X. is supported in part by China Postdoctoral Science Foundation (2023M742099). Some of the calculations were performed in the Nuclear Science Computing Center at Central China Normal University (NSC3), Wuhan, Hubei, China","authors":"Shu-Qing Li, Wen-Jing Xing, Shanshan Cao, Guang-You Qin","doi":"10.1088/1674-1137/ad4c59","DOIUrl":"https://doi.org/10.1088/1674-1137/ad4c59","url":null,"abstract":"Heavy flavor particles provide important probes of the microscopic structure and thermodynamic properties of the quark-gluon plasma (QGP) produced in high-energy nucleus-nucleus collisions. We studied the energy loss and flow of charm and bottom quarks inside the QGP via the nuclear modification factor (<inline-formula>\u0000<tex-math><?CDATA $R_{AA}$?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_084106_M1.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>) and elliptic flow coefficient (<inline-formula>\u0000<tex-math><?CDATA $ v_2 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_084106_M2.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>) of their decayed leptons in heavy-ion collisions at the LHC. The dynamical evolution of the QGP was performed using the CLVisc (3+1)-dimensional viscous hydrodynamics model; the evolution of heavy quarks inside the QGP was simulated with our improved Langevin model that considers both collisional and radiative energy loss of heavy quarks; the hadronization of heavy quarks was simulated via our hybrid coalescence-fragmentation model; and the semi-leptonic decay of <italic toggle=\"yes\">D</italic> and <italic toggle=\"yes\">B</italic> mesons was simulated via PYTHIA. Using the same spatial diffusion coefficient for charm and bottom quarks, we obtained smaller <inline-formula>\u0000<tex-math><?CDATA $R_{AA}$?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_084106_M5.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> and larger <inline-formula>\u0000<tex-math><?CDATA $ v_2 $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_084106_M6.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> of charm decayed leptons than bottom decayed leptons, indicating stronger energy loss of charm quarks than bottom quarks inside the QGP within our current model setup.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"21 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566847","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 : 2024-08-01DOI: 10.1088/1674-1137/ad4c5c
Guo-Yuan Huang
The in-ice or in-water Cherenkov neutrino telescope, such as IceCube, has already proved its power in measuring the Glashow resonance by searching for the bump around arising from the W-boson production. There are many proposals for the next few decades for observations of cosmic tau neutrinos with extensive air showers, also known as tau neutrino telescopes. The air shower telescope is, in principle, sensitive to the Glashow resonance via the channel followed by the tau decay in the air (e.g., TAMBO, which has a geometric area of approximately ). Using a thorough numerical analysis, we find that the discovery significance can be up to 90% with a TAMBO-like setup if PeV neutrinos primarily originate from neutron decays, considering the flux parameters measured by IceCube as the input. The presence of new physics affecting the neutrino flavor composition can also increase the significance. However, if ultrahigh-energy neutrinos are dominantly produced from meson decays, it will be statistically difficult for an advanced proposal such as TAMBO to discriminate the Glashow resonance induced by from the intrinsic background. We have identified several limitations for such advanced telescopes, in comparison with the in-ice or in-water telescope, when measuring resonances: (i) a suppressed branching ratio of 11% for the decay ; (ii) the smearing effect and reduced acceptance because the daughter neutrino takes away 75% of the energy from the W decay; and (iii) a large attenuation effect for Earth-skimming neutrinos with the resonance.
冰内或水中切伦科夫中微子望远镜，如冰立方，已经证明了它在测量格拉肖共振方面的威力，它可以搜索 W 玻色子产生时产生的撞击。在未来的几十年里，有许多关于利用大范围空气淋浴观测宇宙头中微子的建议，这也被称为头中微子望远镜。原则上，空气淋浴望远镜可以通过空气中的陶衰变通道（如 TAMBO，其几何面积约为 ）对格拉肖共振敏感。通过全面的数值分析，我们发现，考虑到冰立方测量的通量参数作为输入，如果PeV中微子主要来源于中子衰变，那么类似于TAMBO的装置的发现意义可达90%。影响中微子味道组成的新物理学的存在也会增加发现的意义。然而，如果超高能中微子主要是由介子衰变产生的，那么像 TAMBO 这样的先进方案就很难从统计上将介子衰变引起的格拉肖共振与固有背景区分开来。与冰内或水内望远镜相比，我们发现了这类先进望远镜在测量共振时的几个局限性：(i)衰变的分支比被抑制了 11%；(ii)由于子中微子带走了 W 衰变 75% 的能量，因此产生了抹黑效应并降低了接受度；(iii)共振对地球掠过中微子产生了很大的衰减效应。
{"title":"Discovery potential of the Glashow resonance in an air shower neutrino telescope* * Project Supported by the ``CUG Scholar'' Scientific Research Funds at China University of Geosciences (Wuhan) (2024014)","authors":"Guo-Yuan Huang","doi":"10.1088/1674-1137/ad4c5c","DOIUrl":"https://doi.org/10.1088/1674-1137/ad4c5c","url":null,"abstract":"The in-ice or in-water Cherenkov neutrino telescope, such as IceCube, has already proved its power in measuring the Glashow resonance by searching for the bump around <inline-formula>\u0000<tex-math><?CDATA $ E^{}_{rm nu} = 6.3; {rm PeV} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_085107_M1.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> arising from the <italic toggle=\"yes\">W</italic>-boson production. There are many proposals for the next few decades for observations of cosmic tau neutrinos with extensive air showers, also known as tau neutrino telescopes. The air shower telescope is, in principle, sensitive to the Glashow resonance via the channel <inline-formula>\u0000<tex-math><?CDATA $ W to tau nu^{}_{tau} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_085107_M2.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> followed by the tau decay in the air (e.g., TAMBO, which has a geometric area of approximately <inline-formula>\u0000<tex-math><?CDATA $ 500; {rm km^2} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_085107_M3.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>). Using a thorough numerical analysis, we find that the discovery significance can be up to 90% with a TAMBO-like setup if PeV neutrinos primarily originate from neutron decays, considering the flux parameters measured by IceCube as the input. The presence of new physics affecting the neutrino flavor composition can also increase the significance. However, if ultrahigh-energy neutrinos are dominantly produced from meson decays, it will be statistically difficult for an advanced proposal such as TAMBO to discriminate the Glashow resonance induced by <inline-formula>\u0000<tex-math><?CDATA $ overline{nu}^{}_{e} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_085107_M5.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> from the intrinsic <inline-formula>\u0000<tex-math><?CDATA $ nu^{}_{tau}/overline{nu}^{}_{tau} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_085107_M6.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> background. We have identified several limitations for such advanced telescopes, in comparison with the in-ice or in-water telescope, when measuring resonances: (i) a suppressed branching ratio of 11% for the decay <inline-formula>\u0000<tex-math><?CDATA $ W to tau nu^{}_{tau} $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_085107_M8.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>; (ii) the smearing effect and reduced acceptance because the daughter neutrino takes away <inline-formula>\u0000<tex-math><?CDATA $ langle y rangle sim $?></tex-math>\u0000<inline-graphic xlink:href=\"cpc_48_8_085107_M9.jpg\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>75% of the energy from the <italic toggle=\"yes\">W</italic> decay; and (iii) a large attenuation effect for Earth-skimming neutrinos with the resonance.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"25 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566844","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 : 2024-08-01DOI: 10.1088/1674-1137/ad432b
Zhenyu Zhang, Yehui Hou, Minyong Guo
In a recent work by Fernandes [Phys. Rev. D 108(6), L061502 (2023)], an exact stationary and axisymmetric solution was discovered in semiclassical gravity with type-A trace anomaly. This was identified as a quantum-corrected version of the Kerr black hole. In this study, we explore the observational signatures of this black hole solution. Our investigation reveals that prograde and retrograde light rings exist, whose radii increase monotonically with the coupling parameter α. When α is negative, the shadow area for the quantum-corrected black hole is smaller than that of the Kerr black hole, whereas when α is positive, the area is larger. For a near-extremal black hole, its high-spin feature (the NHEKline) is found to be highly susceptible to disruption by α. Furthermore, we discuss the images of the quantum-corrected black hole in the presence of a thin accretion disk and compare them to those of the Kerr black hole. Our study highlights the importance of near-horizon emission sources in detecting the effects of quantum corrections by black hole images.
费尔南德斯（Fernandes）最近的一项研究[Phys. Rev. D 108(6), L061502 (2023)]发现，在具有A型痕量异常的半经典引力中，存在一个精确的静止和轴对称解。它被认定为量子修正版的克尔黑洞。在这项研究中，我们探索了这种黑洞方案的观测特征。当α为负值时，量子校正黑洞的阴影面积小于克尔黑洞，而当α为正值时，阴影面积则更大。对于近极值黑洞，我们发现它的高自旋特征（NHEKline）极易受到 α 的干扰。此外，我们还讨论了存在薄吸积盘时量子校正黑洞的图像，并将其与克尔黑洞的图像进行了比较。我们的研究强调了近地平线发射源在通过黑洞图像探测量子修正效应方面的重要性。
{"title":"Observational signatures of rotating black holes in the semiclassical gravity with trace anomaly* * Partly Supported by the National Natural Science Foundation of China (12275004, 12205013, 11873044). MG is also endorsed by ”the Fundamental Research Funds for the Central Universities” (2021NTST13)","authors":"Zhenyu Zhang, Yehui Hou, Minyong Guo","doi":"10.1088/1674-1137/ad432b","DOIUrl":"https://doi.org/10.1088/1674-1137/ad432b","url":null,"abstract":"In a recent work by Fernandes [Phys. Rev. D 108(6), L061502 (2023)], an exact stationary and axisymmetric solution was discovered in semiclassical gravity with type-A trace anomaly. This was identified as a quantum-corrected version of the Kerr black hole. In this study, we explore the observational signatures of this black hole solution. Our investigation reveals that prograde and retrograde light rings exist, whose radii increase monotonically with the coupling parameter <italic toggle=\"yes\">α</italic>. When <italic toggle=\"yes\">α</italic> is negative, the shadow area for the quantum-corrected black hole is smaller than that of the Kerr black hole, whereas when <italic toggle=\"yes\">α</italic> is positive, the area is larger. For a near-extremal black hole, its high-spin feature (the NHEKline) is found to be highly susceptible to disruption by <italic toggle=\"yes\">α</italic>. Furthermore, we discuss the images of the quantum-corrected black hole in the presence of a thin accretion disk and compare them to those of the Kerr black hole. Our study highlights the importance of near-horizon emission sources in detecting the effects of quantum corrections by black hole images.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"18 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566849","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 : 2024-07-31DOI: 10.1088/1674-1137/ad3d4c
Liang-Kai Wu, 良凯 吴, Han Tang, 涵 汤, Ning Li, 宁 李, Xin-Yang Wang and 昕杨 王
We present a lattice QCD determination of masses of the conjectured H-dibaryon, denoted as , at nine different temperatures: 0.24, 0.63, 0.76, 0.84, 0.95, 1.09, 1.27, 1.52, and 1.90. The masses of baryons N, Σ, Ξ, and Λ at different temperatures were also computed. The simulations were performed on an anisotropic lattice with flavours of clover fermion at a quark mass corresponding to . The thermal ensembles were provided by the FASTSUM collaboration, whereas the zero temperature ensembles were provided by the Hadspec collaboration. We also calculated the spectral density of the correlation function of those particles. The spectral density distributions show a rich peak structure at the lowest temperature; at intermediate temperatures, the mass values of those particles obtained by the extrapolation method reflect a two-peak structure. While the spectral density for the octet baryon becomes smooth at 1.27, 1.52, and 1.90, the spectral density for the H-dibaryon becomes smooth at . At , the mass difference of the H-dibaryon and Λ pair, expressed as , was estimated to be MeV, which suggests the existence of a bound H-dibaryon state.
{"title":"Masses of the conjectured H-dibaryon at different temperatures*","authors":"Liang-Kai Wu, 良凯 吴, Han Tang, 涵 汤, Ning Li, 宁 李, Xin-Yang Wang and 昕杨 王","doi":"10.1088/1674-1137/ad3d4c","DOIUrl":"https://doi.org/10.1088/1674-1137/ad3d4c","url":null,"abstract":"We present a lattice QCD determination of masses of the conjectured H-dibaryon, denoted as , at nine different temperatures: 0.24, 0.63, 0.76, 0.84, 0.95, 1.09, 1.27, 1.52, and 1.90. The masses of baryons N, Σ, Ξ, and Λ at different temperatures were also computed. The simulations were performed on an anisotropic lattice with flavours of clover fermion at a quark mass corresponding to . The thermal ensembles were provided by the FASTSUM collaboration, whereas the zero temperature ensembles were provided by the Hadspec collaboration. We also calculated the spectral density of the correlation function of those particles. The spectral density distributions show a rich peak structure at the lowest temperature; at intermediate temperatures, the mass values of those particles obtained by the extrapolation method reflect a two-peak structure. While the spectral density for the octet baryon becomes smooth at 1.27, 1.52, and 1.90, the spectral density for the H-dibaryon becomes smooth at . At , the mass difference of the H-dibaryon and Λ pair, expressed as , was estimated to be MeV, which suggests the existence of a bound H-dibaryon state.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"31 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519022","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 : 2024-07-31DOI: 10.1088/1674-1137/ad4018
Qianchuan Wang, 乾川 王, Junji Jia and 俊基 贾
The periapsis shift of charged test particles in arbitrary static and spherically symmetric charged spacetimes are studied. Two perturbative methods, the near-circular approximation and post-Newtonian methods, are developed and shown to be very accurate when the results are determined to high orders. The near-circular approximation method is more precise when eccentricity e of the orbit is small, whereas the post-Newtonian method is more effective when orbit semilatus rectum p is large. Results from these two methods are shown to agree when both e is small and p is large. These results are then applied to the Reissner-Nordström spacetime, the Einstein-Maxwell-dilation gravity, and a charged wormhole spacetime. The effects of various parameters on the periapsis shift, particularly that of the electrostatic interaction, are carefully studied. The periapsis shift data of the solar-Mercury are then used to constrain the charges of the Sun and Mercury, and the data of the Sgr A*-S2 periapsis shift are used to determine, for the first time using this method, the constraints of the charges of Sgr A* and S2.
研究了带电测试粒子在任意静态和球对称带电时空中的周向位移。提出了两种微扰方法，即近圆近似法和后牛顿法，并证明当结果确定到高阶时，这两种方法非常精确。当轨道偏心率 e 较小时，近圆近似法更为精确，而当轨道半径 p 较大时，后牛顿法更为有效。结果表明，当 e 较小和 p 较大时，这两种方法的结果是一致的。然后将这些结果应用于赖斯纳-诺德斯特伦时空、爱因斯坦-麦克斯韦膨胀引力和带电虫洞时空。我们仔细研究了各种参数对近间隔位移的影响，特别是静电相互作用的影响。然后利用太阳-水星的近地点移动数据来约束太阳和水星的电荷，并利用 Sgr A*-S2 近地点移动的数据来确定 Sgr A* 和 S2 的电荷约束，这是第一次使用这种方法。
{"title":"Periapsis shift in spherically symmetric spacetimes and effects of electric interactions*","authors":"Qianchuan Wang, 乾川 王, Junji Jia and 俊基 贾","doi":"10.1088/1674-1137/ad4018","DOIUrl":"https://doi.org/10.1088/1674-1137/ad4018","url":null,"abstract":"The periapsis shift of charged test particles in arbitrary static and spherically symmetric charged spacetimes are studied. Two perturbative methods, the near-circular approximation and post-Newtonian methods, are developed and shown to be very accurate when the results are determined to high orders. The near-circular approximation method is more precise when eccentricity e of the orbit is small, whereas the post-Newtonian method is more effective when orbit semilatus rectum p is large. Results from these two methods are shown to agree when both e is small and p is large. These results are then applied to the Reissner-Nordström spacetime, the Einstein-Maxwell-dilation gravity, and a charged wormhole spacetime. The effects of various parameters on the periapsis shift, particularly that of the electrostatic interaction, are carefully studied. The periapsis shift data of the solar-Mercury are then used to constrain the charges of the Sun and Mercury, and the data of the Sgr A*-S2 periapsis shift are used to determine, for the first time using this method, the constraints of the charges of Sgr A* and S2.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"24 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141531267","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 : 2024-07-31DOI: 10.1088/1674-1137/ad34bc
Muhammad Arslan, Tahira Yasmeen, Saba Shafaq, Ishtiaq Ahmed and Muhammad Jamil Aslam
Recently, the experimental measurements of the branching ratios and different polarization asymmetries for processes occurring through flavor-changing-charged current transitions by BABAR, Belle, and LHCb have revealed some significant differences from the corresponding Standard Model (SM) predictions. This has triggered an interest to search for physics beyond the SM in the context of various new physics (NP) models and using the model-independent weak effective Hamiltonian (WEH). Assuming left-handed neutrinos, we add the dimension-six vector, (pseudo-)scalar, and tensor operators with complex Wilson coefficients (WCs) to the SM WEH. Using 60%, 30%, and 10% constraints resulting from the branching ratio of , we reassess the parametric space of these new physics WCs accommodating the current anomalies based on the most recent HFLAV data of and and Belle data of and . We find that the allowed parametric region of left-handed scalar couplings strongly depends on the constraints of the branching ratio, and the maximum pull from the SM predictions results from the <60% branching ratio limit. Also, the parametric region changes significantly if we extend the analysis by adding LHCb data of and . Furthermore, due to the large uncertainties in the measurements of and , we derive the sum rules which complement them with and . Using the best-fit points of the new complex WCs along with the latest measurements of , we predict the numerical values of the observable , , and from the sum rules. The simultaneous dependence of abovementioned physical observables on the NP WCs is established by plotting their correlation with and , which are useful to discriminate between various NP scenarios. We find that the most significant impact of NP results from the WC . Finally, we study the impact of these NP couplings on various angular and triple product asymmetries that could be measured in some ongoing and future experiments. The precise measurements of these observables are important to check the SM and extract the possible NP.
{"title":"Analysis of anomalies using weak effective Hamiltonian with complex couplings and their impact on various physical observables","authors":"Muhammad Arslan, Tahira Yasmeen, Saba Shafaq, Ishtiaq Ahmed and Muhammad Jamil Aslam","doi":"10.1088/1674-1137/ad34bc","DOIUrl":"https://doi.org/10.1088/1674-1137/ad34bc","url":null,"abstract":"Recently, the experimental measurements of the branching ratios and different polarization asymmetries for processes occurring through flavor-changing-charged current transitions by BABAR, Belle, and LHCb have revealed some significant differences from the corresponding Standard Model (SM) predictions. This has triggered an interest to search for physics beyond the SM in the context of various new physics (NP) models and using the model-independent weak effective Hamiltonian (WEH). Assuming left-handed neutrinos, we add the dimension-six vector, (pseudo-)scalar, and tensor operators with complex Wilson coefficients (WCs) to the SM WEH. Using 60%, 30%, and 10% constraints resulting from the branching ratio of , we reassess the parametric space of these new physics WCs accommodating the current anomalies based on the most recent HFLAV data of and and Belle data of and . We find that the allowed parametric region of left-handed scalar couplings strongly depends on the constraints of the branching ratio, and the maximum pull from the SM predictions results from the <60% branching ratio limit. Also, the parametric region changes significantly if we extend the analysis by adding LHCb data of and . Furthermore, due to the large uncertainties in the measurements of and , we derive the sum rules which complement them with and . Using the best-fit points of the new complex WCs along with the latest measurements of , we predict the numerical values of the observable , , and from the sum rules. The simultaneous dependence of abovementioned physical observables on the NP WCs is established by plotting their correlation with and , which are useful to discriminate between various NP scenarios. We find that the most significant impact of NP results from the WC . Finally, we study the impact of these NP couplings on various angular and triple product asymmetries that could be measured in some ongoing and future experiments. The precise measurements of these observables are important to check the SM and extract the possible NP.","PeriodicalId":10250,"journal":{"name":"中国物理C","volume":"28 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519020","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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