A massive black hole can develop a dark-matter overdensity, and the dark matter changes the evolution of a stellar-mass compact object inspiraling around the massive black hole through the dense dark-matter environment. Specifically, dynamical friction speeds up the inspiral of the compact object and causes feedback on the dark-matter distribution. These intermediate mass-ratio inspirals with dark matter are a source of gravitational waves (GWs), and the waves can dephase significantly from an equivalent system in vacuum. Prior work has shown that this dephasing needs to be modeled to detect the GWs from these systems with LISA (the Laser Interferometer Space Antenna); it also showed that the density and distribution of dark matter can be inferred from a GW measurement. In this paper, we study whether the parametrized post-Einsteinian (ppE) framework can be used to infer the presence of dark matter in these systems. We confirm that if vacuum waveform templates are used to model the GWs from an inspiral in a dark-matter halo, then the resulting parameter estimation is biased. We then apply the ppE framework to determine whether it can reduce the parameter-estimation biases, and we find that adding one ppE phase term to a waveform template eliminates the parameter-estimation biases (statistical errors become larger than the systematic ones), but the effective post-Newtonian order in the ppE framework must be specified without uncertainties. When the post-Newtonian order has uncertainty, we find that the systematic errors on the ppE and the binary's parameters exceed the statistical errors. Thus, the simplest ppE framework would not give unbiased results for these systems, and a further extension of it, or dedicated parameter estimation with gravitational waveforms that include dark-matter effects would be needed.
大质量黑洞会产生暗物质超密度，而暗物质会改变围绕大质量黑洞吸积的恒星质量紧凑天体穿过高密度暗物质环境时的演化过程。这些中等质量比的暗物质吸积是引力波（GWs）的一个来源，引力波可以从一个等效的真空系统中大幅消相。先前的研究表明，要利用激光干涉仪空间天线（LISA）探测到来自这些系统的引力波，需要对这种去相进行建模；研究还表明，可以从引力波测量中推断出暗物质的密度和分布。在本文中，我们研究了参数化的后爱因斯坦（ppE）框架是否可以用来推断这些系统中暗物质的存在。我们证实，如果使用真空波形模板来模拟暗物质光环中的吸气产生的全球变暖，那么得出的参数估计是有偏差的。我们发现，在波形模板中加入一个ppE相位项可以消除参数估计偏差（统计误差变得比系统误差大），但是ppE框架中的有效牛顿后阶必须在不确定的情况下指定。当后牛顿阶具有不确定性时，我们会发现 ppE 和二元参数的系统误差会超过统计误差。因此，对这些系统来说，最简单的 ppE 框架并不能给出无偏的结果，还需要进一步扩展，或者用包含暗物质效应的引力波形式进行专门的参数估计。
{"title":"Probing dark-matter effects with gravitational waves using the parameterized post-Einsteinian framework","authors":"Eileen Wilcox, David Nichols, Kent Yagi","doi":"arxiv-2409.10846","DOIUrl":"https://doi.org/arxiv-2409.10846","url":null,"abstract":"A massive black hole can develop a dark-matter overdensity, and the dark\u0000matter changes the evolution of a stellar-mass compact object inspiraling\u0000around the massive black hole through the dense dark-matter environment.\u0000Specifically, dynamical friction speeds up the inspiral of the compact object\u0000and causes feedback on the dark-matter distribution. These intermediate\u0000mass-ratio inspirals with dark matter are a source of gravitational waves\u0000(GWs), and the waves can dephase significantly from an equivalent system in\u0000vacuum. Prior work has shown that this dephasing needs to be modeled to detect\u0000the GWs from these systems with LISA (the Laser Interferometer Space Antenna);\u0000it also showed that the density and distribution of dark matter can be inferred\u0000from a GW measurement. In this paper, we study whether the parametrized\u0000post-Einsteinian (ppE) framework can be used to infer the presence of dark\u0000matter in these systems. We confirm that if vacuum waveform templates are used\u0000to model the GWs from an inspiral in a dark-matter halo, then the resulting\u0000parameter estimation is biased. We then apply the ppE framework to determine\u0000whether it can reduce the parameter-estimation biases, and we find that adding\u0000one ppE phase term to a waveform template eliminates the parameter-estimation\u0000biases (statistical errors become larger than the systematic ones), but the\u0000effective post-Newtonian order in the ppE framework must be specified without\u0000uncertainties. When the post-Newtonian order has uncertainty, we find that the\u0000systematic errors on the ppE and the binary's parameters exceed the statistical\u0000errors. Thus, the simplest ppE framework would not give unbiased results for\u0000these systems, and a further extension of it, or dedicated parameter estimation\u0000with gravitational waveforms that include dark-matter effects would be needed.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258866","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}
Navdeep Singh Dhindsa, Nilmani Mathur, M. Padmanath
We present a lattice calculation of dibaryons composed of single-flavor quarks with either charm or strange quark mass. We utilize a set of lattice QCD ensembles with $N_f=2+1+1$ dynamical HISQ fields, two spatial volumes, and four different lattice spacings generated by the MILC collaboration. By using an overlap action for the valence quark propagators, we calculate the ground state energies of dibaryons in $S = 0$ and $S = 2$ spin channels. By analyzing the energy difference of the ground state of the dibaryon with respect to the relevant threshold, we provide insights into the interactions involved in different spin channels at the charm and the strange quark masses.
{"title":"Exploring Single-Flavor Dibaryons: A lattice perspective","authors":"Navdeep Singh Dhindsa, Nilmani Mathur, M. Padmanath","doi":"arxiv-2409.10167","DOIUrl":"https://doi.org/arxiv-2409.10167","url":null,"abstract":"We present a lattice calculation of dibaryons composed of single-flavor\u0000quarks with either charm or strange quark mass. We utilize a set of lattice QCD\u0000ensembles with $N_f=2+1+1$ dynamical HISQ fields, two spatial volumes, and four\u0000different lattice spacings generated by the MILC collaboration. By using an\u0000overlap action for the valence quark propagators, we calculate the ground state\u0000energies of dibaryons in $S = 0$ and $S = 2$ spin channels. By analyzing the\u0000energy difference of the ground state of the dibaryon with respect to the\u0000relevant threshold, we provide insights into the interactions involved in\u0000different spin channels at the charm and the strange quark masses.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258928","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}
In a previous work we have shown that the data presented by the two long-baseline accelerator experiments NO$nu$A and T2K at the Neutrino 2020 conference displayed a tension, and that it could be alleviated by non-standard neutrino interactions (NSI) of the flavor changing type involving the $e-mu$ or the $e-tau$ sectors with couplings $|varepsilon_{emu}| sim |varepsilon_{etau}|sim 0.1$. As a consequence a hint in favor of NSI emerged. In the present paper we reassess the issue in light of the new data released by the two experiments at the Neutrino 2024 conference. We find that the tension in the determination of the standard CP-phase $delta_{mathrm {CP}}$ extracted by the two experiments in the normal neutrino mass ordering persists and has a statistical significance of $sim2sigma$. Concerning the NSI, we find that including their effects in the fit, the two values of $delta_{mathrm {CP}}$ preferred by NO$nu$A and T2K return in very good agreement. The current statistical significance of the hint of non zero NSI is $sim1.8sigma$. Further experimental data are needed in order to settle the issue.
{"title":"Status of tension between NO$ν$A and T2K after Neutrino 2024 and possible role of non-standard neutrino interactions","authors":"Sabya Sachi Chatterjee, Antonio Palazzo","doi":"arxiv-2409.10599","DOIUrl":"https://doi.org/arxiv-2409.10599","url":null,"abstract":"In a previous work we have shown that the data presented by the two\u0000long-baseline accelerator experiments NO$nu$A and T2K at the Neutrino 2020\u0000conference displayed a tension, and that it could be alleviated by non-standard\u0000neutrino interactions (NSI) of the flavor changing type involving the $e-mu$\u0000or the $e-tau$ sectors with couplings $|varepsilon_{emu}| sim\u0000|varepsilon_{etau}|sim 0.1$. As a consequence a hint in favor of NSI\u0000emerged. In the present paper we reassess the issue in light of the new data\u0000released by the two experiments at the Neutrino 2024 conference. We find that\u0000the tension in the determination of the standard CP-phase $delta_{mathrm\u0000{CP}}$ extracted by the two experiments in the normal neutrino mass ordering\u0000persists and has a statistical significance of $sim2sigma$. Concerning the\u0000NSI, we find that including their effects in the fit, the two values of\u0000$delta_{mathrm {CP}}$ preferred by NO$nu$A and T2K return in very good\u0000agreement. The current statistical significance of the hint of non zero NSI is\u0000$sim1.8sigma$. Further experimental data are needed in order to settle the\u0000issue.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258864","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}
The existence of axions or Axion-Like Particles (ALPs) has been predicted by various Beyond Standard Model (BSM) theories, and the proposed photon-ALP interaction is one of the ways to probe them. Such an interaction will lead to photon-ALP resonant conversion in galaxy clusters, resulting in a polarized spectral distortion in the CMB along the cluster line of sight. The estimation of this signal from galaxy clusters requires an estimation of the electron density and magnetic field in galaxy clusters. We have developed a new Bayesian framework texttt{SpectrAx} that can use observations from different electromagnetic bands such as radio, CMB, optical, and X-ray to infer the astrophysical properties of a galaxy cluster, such as cluster its redshift, electron density and magnetic field, along with the BSM physics such as ALPs. By using the simulated data for upcoming CMB surveys such as Simons Observatory (SO) and CMB-S4 in combination with Square Kilometer Array (SKA) and extended ROentgen Survey with an Imaging Telescope Array (eROSITA) we demonstrate the capability in accurately inferring the ALPs coupling strength along with the radial profile of electron density and magnetic field from galaxy clusters. The application of this framework to the data from future surveys by combining SKA+SO+eROSITA and SKA+CMB-S4+eROSITA will make it possible for the first time to explore both astrophysics and BSM physics from low-redshift galaxy clusters using a multi-band approach.
{"title":"SpectrAx: Spectral Search of Axion-Like Particles Using Multi-Band Observations of Galaxy Clusters from SKA, SO, CMB-S4 and eROSITA","authors":"Harsh Mehta, Suvodip Mukherjee","doi":"arxiv-2409.10632","DOIUrl":"https://doi.org/arxiv-2409.10632","url":null,"abstract":"The existence of axions or Axion-Like Particles (ALPs) has been predicted by\u0000various Beyond Standard Model (BSM) theories, and the proposed photon-ALP\u0000interaction is one of the ways to probe them. Such an interaction will lead to\u0000photon-ALP resonant conversion in galaxy clusters, resulting in a polarized\u0000spectral distortion in the CMB along the cluster line of sight. The estimation\u0000of this signal from galaxy clusters requires an estimation of the electron\u0000density and magnetic field in galaxy clusters. We have developed a new Bayesian\u0000framework texttt{SpectrAx} that can use observations from different\u0000electromagnetic bands such as radio, CMB, optical, and X-ray to infer the\u0000astrophysical properties of a galaxy cluster, such as cluster its redshift,\u0000electron density and magnetic field, along with the BSM physics such as ALPs.\u0000By using the simulated data for upcoming CMB surveys such as Simons Observatory\u0000(SO) and CMB-S4 in combination with Square Kilometer Array (SKA) and extended\u0000ROentgen Survey with an Imaging Telescope Array (eROSITA) we demonstrate the\u0000capability in accurately inferring the ALPs coupling strength along with the\u0000radial profile of electron density and magnetic field from galaxy clusters. The\u0000application of this framework to the data from future surveys by combining\u0000SKA+SO+eROSITA and SKA+CMB-S4+eROSITA will make it possible for the first time\u0000to explore both astrophysics and BSM physics from low-redshift galaxy clusters\u0000using a multi-band approach.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258984","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}
Emilio J. Estrada, Sergi Gonzàlez-Solís, Adolfo Guevara, Pablo Roig
Working with Resonance Chiral Theory, within the two resonance multiplets saturation scheme, we satisfy leading (and some subleading) chiral and asymptotic QCD constraints and accurately fit simultaneously the $pi^{0},eta,eta^{prime}$ transition form factors, for single and double virtuality. In the latter case, we supplement the few available measurements with lattice data to ensure a faithful description. Mainly due to the new results for the doubly virtual case, we improve over existing descriptions for the $eta$ and $eta^prime$. Our evaluation of the corresponding pole contributions to the hadronic light-by-light piece of the muon $g-2$ read: $a_mu^{pi^{0}text{-}rm{pole}}=left(60.4pm0.5^{+3.2}_{-1.8}right)times10^{-11}$, $a_mu^{etatext{-}mathrm{pole}}=left(15.2pm0.5^{+1.1}_{-0.7}right)times10^{-11}$ and $a_mu^{eta^primetext{-}rm{pole}}=left(14.4pm0.8^{+1.4}_{-1.0}right)times10^{-11}$, for a total of $a_mu^{pi^0+eta+eta^{prime}text{-}rm{pole}}=left(90.0pm1.1^{+3.7}_{-2.2}right)times10^{-11}$, where the first and second error are the statistical and systematic uncertainties, respectively.
通过共振手性理论（Resonance Chiral Theory），在两个共振多重饱和方案中，我们满足了领先的（以及一些次领先的）手性和渐近QCD约束，并同时精确地拟合了单虚拟性和双虚拟性的$/pi^{0},eta,eta^{prime}$过渡形式因子。在后一种情况下，我们用晶格数据补充了为数不多的可用测量数据，以确保忠实描述。主要由于双虚情况下的新结果，我们改进了对$eta$和$eta^prime$的现有描述。我们对μ介子$g-2$的强子逐光片的相应极点贡献的评估是：$a_mu^{pi^{0}text{-}rm{pole}}=left(60.4pm0.5^{+3.2}_{-1.8}right)times10^{-11}$,$a_mu^{etatext{-}mathrm{pole}}=left(15.2pm0.5^{+1.1}_{-0.7}right)times10^{-11}$and$a_mu^{eta^primetext{-}rm{pole}}=left(14.4pm0.8^{+1.4}_{-1.0}right)times10^{-11}$,for a total of$a_mu^{pi^0+eta+eta^{prime}text{-}rm{pole}}=left(90.0/pm1.1^{+3.7}_{-2.2}/right)/times10^{-11}$，其中第一个和第二个误差分别是统计不确定性和系统不确定性。
{"title":"Improved $π^0,η,η^{prime}$ transition form factors in resonance chiral theory and their $a_μ^{rm{HLbL}}$ contribution","authors":"Emilio J. Estrada, Sergi Gonzàlez-Solís, Adolfo Guevara, Pablo Roig","doi":"arxiv-2409.10503","DOIUrl":"https://doi.org/arxiv-2409.10503","url":null,"abstract":"Working with Resonance Chiral Theory, within the two resonance multiplets\u0000saturation scheme, we satisfy leading (and some subleading) chiral and\u0000asymptotic QCD constraints and accurately fit simultaneously the\u0000$pi^{0},eta,eta^{prime}$ transition form factors, for single and double\u0000virtuality. In the latter case, we supplement the few available measurements\u0000with lattice data to ensure a faithful description. Mainly due to the new\u0000results for the doubly virtual case, we improve over existing descriptions for\u0000the $eta$ and $eta^prime$. Our evaluation of the corresponding pole\u0000contributions to the hadronic light-by-light piece of the muon $g-2$ read:\u0000$a_mu^{pi^{0}text{-}rm{pole}}=left(60.4pm0.5^{+3.2}_{-1.8}right)times10^{-11}$,\u0000$a_mu^{etatext{-}mathrm{pole}}=left(15.2pm0.5^{+1.1}_{-0.7}right)times10^{-11}$\u0000and\u0000$a_mu^{eta^primetext{-}rm{pole}}=left(14.4pm0.8^{+1.4}_{-1.0}right)times10^{-11}$,\u0000for a total of\u0000$a_mu^{pi^0+eta+eta^{prime}text{-}rm{pole}}=left(90.0pm1.1^{+3.7}_{-2.2}right)times10^{-11}$,\u0000where the first and second error are the statistical and systematic\u0000uncertainties, respectively.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258817","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}
Yi LiaoSouth China Normal U., Xiao-Dong MaSouth China Normal U., Hao-Lin WangSouth China Normal U.
We investigate the impact of effective interactions of dimension-8 (dim-8) operators in the standard model effective field theory (SMEFT) on neutral meson mixing, focusing on the $K^0-bar K^0$, $B_{d,s}-bar B_{d,s}$, and $D^0-bar D^0$ systems. Within the framework of the low energy effective field theory (LEFT), each system is governed by eight dim-6 operators, with four originating at tree level from dim-6 SMEFT operators and the other four from dim-8 SMEFT operators. Notably, in certain UV complete models those dim-8 operators instead of the dim-6 ones are generated at the leading order. Our analysis focuses on those dim-8 operators and includes their one-loop QCD renormalization group running effects. By leveraging the LEFT master formula we impose stringent constraints on the effective scales associated with these dim-8 operators. We find that neutral meson mixing can probe an effective scale up to 50 TeV for some operators, surpassing the constraints imposed on other dim-8 operators by other observables. Lastly, we present a UV complete model capable of generating dim-8 operators at the leading order, thus offering a unique perspective on the interplay between different operator dimensions in probing new physics phenomena.
{"title":"Probing dimension-8 SMEFT operators through neutral meson mixing","authors":"Yi LiaoSouth China Normal U., Xiao-Dong MaSouth China Normal U., Hao-Lin WangSouth China Normal U.","doi":"arxiv-2409.10305","DOIUrl":"https://doi.org/arxiv-2409.10305","url":null,"abstract":"We investigate the impact of effective interactions of dimension-8 (dim-8)\u0000operators in the standard model effective field theory (SMEFT) on neutral meson\u0000mixing, focusing on the $K^0-bar K^0$, $B_{d,s}-bar B_{d,s}$, and $D^0-bar\u0000D^0$ systems. Within the framework of the low energy effective field theory\u0000(LEFT), each system is governed by eight dim-6 operators, with four originating\u0000at tree level from dim-6 SMEFT operators and the other four from dim-8 SMEFT\u0000operators. Notably, in certain UV complete models those dim-8 operators instead\u0000of the dim-6 ones are generated at the leading order. Our analysis focuses on\u0000those dim-8 operators and includes their one-loop QCD renormalization group\u0000running effects. By leveraging the LEFT master formula we impose stringent\u0000constraints on the effective scales associated with these dim-8 operators. We\u0000find that neutral meson mixing can probe an effective scale up to 50 TeV for\u0000some operators, surpassing the constraints imposed on other dim-8 operators by\u0000other observables. Lastly, we present a UV complete model capable of generating\u0000dim-8 operators at the leading order, thus offering a unique perspective on the\u0000interplay between different operator dimensions in probing new physics\u0000phenomena.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258873","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}
Dark matter with mass in the crossover range between wave dark matter and particle dark matter, around $(10^{-3},, 10^3),$eV, remains relatively unexplored by terrestrial experiments. In this mass regime, dark matter scatters coherently with macroscopic objects. The effect of the coherent scattering greatly enhances the accelerations of the targets that the dark matter collisions cause by a factor of $sim 10^{23}$. We propose a novel torsion balance experiment with test bodies of different geometric sizes to detect such dark matter-induced acceleration. This method provides the strongest constraints on the scattering cross-section between the dark matter and a nucleon in the mass range $(10^{-5}, 10^3),$eV.
{"title":"Detection of Dark Matter Coherent Scattering via Torsion Balance with Test Bodies of Different Sizes","authors":"Shigeki Matsumoto, Jie Sheng, Chuan-Yang Xing","doi":"arxiv-2409.09950","DOIUrl":"https://doi.org/arxiv-2409.09950","url":null,"abstract":"Dark matter with mass in the crossover range between wave dark matter and\u0000particle dark matter, around $(10^{-3},, 10^3),$eV, remains relatively\u0000unexplored by terrestrial experiments. In this mass regime, dark matter\u0000scatters coherently with macroscopic objects. The effect of the coherent\u0000scattering greatly enhances the accelerations of the targets that the dark\u0000matter collisions cause by a factor of $sim 10^{23}$. We propose a novel\u0000torsion balance experiment with test bodies of different geometric sizes to\u0000detect such dark matter-induced acceleration. This method provides the\u0000strongest constraints on the scattering cross-section between the dark matter\u0000and a nucleon in the mass range $(10^{-5}, 10^3),$eV.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258872","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 study the $J/psi$ photoproduction $gamma pto J/psi p$ near threshold to investigate the role played by the open charm channels and possible signals from the hidden charm $P_c$ pentaquark states. With the diffractive mechanism described by a Pomeron exchange model extrapolated from high energies to the lower energy region, it shows that the differential cross sections compared with the recent results from the GlueX Collaboration have apparent deficits in the large scattering angles. The inclusion of the open charm channels and intermediate $P_c$ states can significantly improve the descriptions of the differential cross section data, in particular, at the energy regions of the $Lambda_cbar{D}^{(*)}$ thresholds. This can explain the structures observed by the GlueX Collaboration at the $Lambda_cbar{D}^{(*)}$ thresholds as the open charm CUSP effects. Given that these $P_c$ pentaquark states are hadronic molecules dynamically generated by the $Sigma_cbar{D}^{(*)}$, we find that the production of these $P_c$ states should be suppressed at leading order since their couplings to both $gamma p$ and $J/psi p$ are through loop transitions. This can explain why no obvious signals for the $P_c$ states are observed by the present datasets. In order to further disentangling the role played by $s$-channel mechanisms, we also investigate the polarized beam asymmetry which shows sensitivities to the open charm threshold effects and interferences from the $P_c$ productions. Experimental measurement of this observable at the Jefferson Laboratory is strongly encouraged.
{"title":"$J/ψ$ photoproduction near threshold and signals for the hidden charm pentaquarks","authors":"Ming-Xiao Duan, Chang Gong, Lin Qiu, Qiang Zhao","doi":"arxiv-2409.10364","DOIUrl":"https://doi.org/arxiv-2409.10364","url":null,"abstract":"We study the $J/psi$ photoproduction $gamma pto J/psi p$ near threshold\u0000to investigate the role played by the open charm channels and possible signals\u0000from the hidden charm $P_c$ pentaquark states. With the diffractive mechanism\u0000described by a Pomeron exchange model extrapolated from high energies to the\u0000lower energy region, it shows that the differential cross sections compared\u0000with the recent results from the GlueX Collaboration have apparent deficits in\u0000the large scattering angles. The inclusion of the open charm channels and\u0000intermediate $P_c$ states can significantly improve the descriptions of the\u0000differential cross section data, in particular, at the energy regions of the\u0000$Lambda_cbar{D}^{(*)}$ thresholds. This can explain the structures observed\u0000by the GlueX Collaboration at the $Lambda_cbar{D}^{(*)}$ thresholds as the\u0000open charm CUSP effects. Given that these $P_c$ pentaquark states are hadronic\u0000molecules dynamically generated by the $Sigma_cbar{D}^{(*)}$, we find that\u0000the production of these $P_c$ states should be suppressed at leading order\u0000since their couplings to both $gamma p$ and $J/psi p$ are through loop\u0000transitions. This can explain why no obvious signals for the $P_c$ states are\u0000observed by the present datasets. In order to further disentangling the role\u0000played by $s$-channel mechanisms, we also investigate the polarized beam\u0000asymmetry which shows sensitivities to the open charm threshold effects and\u0000interferences from the $P_c$ productions. Experimental measurement of this\u0000observable at the Jefferson Laboratory is strongly encouraged.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258867","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}
Domain walls are topological defects produced by the spontaneous symmetry-breaking of discrete symmetry during cosmological phase transitions. The horizon-size domain wall can significantly contribute to the energy density in the late-evolution stage. We propose that the density perturbations from the fluctuations in the number density of the horizon-size domain wall could collapse to form primordial black holes. This mechanism becomes effective when the domain wall energy density ratio to that of the radiation reaches about 0.1 in the radiation-dominated universe. We find that models with $Z_2$ symmetry are excluded for interpreting pulsar timing array observations on the nano-Hz gravitational wave background since this model's domain wall number density fluctuations could lead to an overabundance of the primordial black holes. Moreover, models with $Nsim 10$ domain walls also suffer strong constraints from the overabundance of primordial black holes.
{"title":"Primordial black hole from domain wall fluctuations","authors":"Bo-Qiang Lu, Cheng-Wei Chiang, Tianjun Li","doi":"arxiv-2409.09986","DOIUrl":"https://doi.org/arxiv-2409.09986","url":null,"abstract":"Domain walls are topological defects produced by the spontaneous\u0000symmetry-breaking of discrete symmetry during cosmological phase transitions.\u0000The horizon-size domain wall can significantly contribute to the energy density\u0000in the late-evolution stage. We propose that the density perturbations from the\u0000fluctuations in the number density of the horizon-size domain wall could\u0000collapse to form primordial black holes. This mechanism becomes effective when\u0000the domain wall energy density ratio to that of the radiation reaches about 0.1\u0000in the radiation-dominated universe. We find that models with $Z_2$ symmetry\u0000are excluded for interpreting pulsar timing array observations on the nano-Hz\u0000gravitational wave background since this model's domain wall number density\u0000fluctuations could lead to an overabundance of the primordial black holes.\u0000Moreover, models with $Nsim 10$ domain walls also suffer strong constraints\u0000from the overabundance of primordial black holes.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258931","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}
The masses, the fine-structure splitting, and two-photon decay widths of the higher $nP$-charmonium states are calculated in the relativistic string model, reduced to the spinless Salpeter equation, where the static potential has no fitting parameters and the $c-$quark mass has the physical value. The resulting masses of $h_c(3P)$, $chi_{c1}(3P)$, $chi_{c0}(4P)$, $chi_{c0}(5P)$, $chi_{c1}(5P)$ are obtained in a good agreement with the experimental masses of the LHCb resonances: $h_c(4300)$, $chi_{c1}(4274)$, $X(4500)$, $X(4700)$, $X(4685)$. To test sensitivity of results to a chosen gluon-exchange (GE) potential, three types of $V_{ge}(r)$ are considered. In first case the non-screened GE potential with large vector coupling at asymptotic, $alpha_{rm V}(rm asym.)=0.635$, and the $c$-quark mass $m_c=1.430$ GeV are taken; in second case a screened $V_{ge}$ and $m_c=1.385$ are investigated, and in third case the GE potential is totally suppressed, $V_{ge}=0$, and $m_c=1.32$ GeV. The agreement with experiment is reached only if the same (universal) flattened confining potential, introduced in the analysis of the radial Regge trajectories of light mesons, is used. The unobserved $6P,0^+$ resonance with the mass $cong 4.81$ GeV, near $J/psiphi(1680)$ threshold, is predicted. Our analysis shows that the screening of the GE potential is possible but weakly affects the physical results obtained. The calculated two-photon decay widths weakly differ in the three cases but may become an important factor, which distinguishes $cbar c$ and four-quark states.
{"title":"The higher $χ_{cJ}(nP)$, $h_c(nP)$ states and the role of the gluon-exchange potential","authors":"A. M. Badalian","doi":"arxiv-2409.10761","DOIUrl":"https://doi.org/arxiv-2409.10761","url":null,"abstract":"The masses, the fine-structure splitting, and two-photon decay widths of the\u0000higher $nP$-charmonium states are calculated in the relativistic string model,\u0000reduced to the spinless Salpeter equation, where the static potential has no\u0000fitting parameters and the $c-$quark mass has the physical value. The resulting\u0000masses of $h_c(3P)$, $chi_{c1}(3P)$, $chi_{c0}(4P)$, $chi_{c0}(5P)$,\u0000$chi_{c1}(5P)$ are obtained in a good agreement with the experimental masses\u0000of the LHCb resonances: $h_c(4300)$, $chi_{c1}(4274)$, $X(4500)$, $X(4700)$,\u0000$X(4685)$. To test sensitivity of results to a chosen gluon-exchange (GE)\u0000potential, three types of $V_{ge}(r)$ are considered. In first case the\u0000non-screened GE potential with large vector coupling at asymptotic,\u0000$alpha_{rm V}(rm asym.)=0.635$, and the $c$-quark mass $m_c=1.430$ GeV are\u0000taken; in second case a screened $V_{ge}$ and $m_c=1.385$ are investigated, and\u0000in third case the GE potential is totally suppressed, $V_{ge}=0$, and\u0000$m_c=1.32$ GeV. The agreement with experiment is reached only if the same\u0000(universal) flattened confining potential, introduced in the analysis of the\u0000radial Regge trajectories of light mesons, is used. The unobserved $6P,0^+$\u0000resonance with the mass $cong 4.81$ GeV, near $J/psiphi(1680)$ threshold, is\u0000predicted. Our analysis shows that the screening of the GE potential is\u0000possible but weakly affects the physical results obtained. The calculated\u0000two-photon decay widths weakly differ in the three cases but may become an\u0000important factor, which distinguishes $cbar c$ and four-quark states.","PeriodicalId":501067,"journal":{"name":"arXiv - PHYS - High Energy Physics - Phenomenology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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