New Physics Searches at Kaon and Hyperon Factories
Evgueni Goudzovski, Diego Redigolo, Kohsaku Tobioka, Jure Zupan, Gonzalo Alonso-Alvarez, Daniele S. M. Alves, Saurabh Bansal, Martin Bauer, Joachim Brod, Veroni… 展开作者
Evgueni Goudzovski, Diego Redigolo, Kohsaku Tobioka, Jure Zupan, Gonzalo Alonso-Alvarez, Daniele S. M. Alves, Saurabh Bansal, Martin Bauer, Joachim Brod, Veronika Chobanova, Giancarlo D'Ambrosio, Alakabha Datta, Avital Dery, Francesco Dettori, Bogdan A. Dobrescu, Babette Dobrich, Daniel Egana-Ugrinovic, Gilly Elor, Miguel Escudero, Marco Fabbrichesi, Bartosz Fornal, Patrick J. Fox, Emidio Gabrielli, Li-Sheng Geng, Vladimir V. Gligorov, Martin Gorbahn, Stefania Gori, Benjamin Grinstein, Yuval Grossman, Diego Guadagnoli, Samuel Homiller, Matheus Hostert, Kevin J. Kelly, Teppei Kitahara, Simon Knapen, Gordan Krnjaic, Andrzej Kupsc, Sandra Kvedaraite, Gaia Lanfranchi, Danny Marfatia, Jorge Martin Camalich, Diego Martinez Santos, Karim Massri, Patrick Mead, Matthew Moulson, Hajime Nanjo, Matthias Neubert, Maxim Pospelov, Sophie Renner, Stefan Schacht, Marvin Schnubel, Rui-Xiang Shi, Brian Shuve, Tommaso Spadaro, Yotam Soreq, Emmanuel Stamou, Olcyr Sumensari, Michele Tammaro, Jorge Terol-Calvo, Andrea Thamm, Yu-Chen Tung, Dayong Wang, Kei Yamamoto, Robert Ziegler
备注：
108 pages, 25 figures, 9 tables, matches the published version
Rare meson decays are among the most sensitive probes of both heavy and light new physics. Among them, new physics searches using kaons benefit from their small total decay widths and the availability of very large datasets. On the other hand, useful complementary information is provided by hyperon decay measurements. We summarize the relevant phenomenological models and the status of the searches in a comprehensive list of kaon and hyperon decay channels. We identify new search strategies for under-explored signatures, and demonstrate that the improved sensitivities from current and next-generation experiments could lead to a qualitative leap in the exploration of light dark sectors.
In this work we study the low energy kaon-hyperon interaction considering effective chiral Lagrangians that include kaons, $σ$ mesons, hyperons and the corresponding resonances. We calculate the scattering amplitudes, and then the total cross sections, angular distributions, polarizations and the $S$ and $P$ phase shifts.
In this work the low energy kaon-hyperon interaction is studied with nonlinear chiral invariant Lagragians considering kaons, hyperons, and the corresponding resonances in the intermediate states. We show the basic formalism to calculate the total cross sections, angular distributions, and some diagrams of interest.
In this paper, we study the low energy kaon-hyperon interaction considering effective chiral Lagrangians that include kaons, $σ$ mesons, hyperons and the corresponding resonances. The scattering amplitudes are calculated and then we determine the angular distributions and polarizations.
We investigate the single transverse-spin asymmetry with a $\sin (ϕ_h-ϕ_S)$ modulation in the charged Kaon produced and in $Λ$ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent (TMD) factorization at the next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of Sivers function and the unpolarized fragmentation function $D_1$ for the produced hadron. The parametrization for the proton Qiu-Sterman function, which is closely related to the Sivers function, is adopted to numerically estimate the Sivers asymmetry at the kine…
We entertain the possibility that scalar leptoquarks (LQs) generate consequential effects on the strangeness-changing decays of hyperons and kaons involving missing energy carried away by a pair of invisible fermions. Although such processes have suppressed rates in the standard model (SM), they could get significant enhancement in the presence of the LQs. In order to respect the available data on the kaon modes $K\toπν\barν$ and increase the rates of the hyperon decays substantially at the same time, two different scalar LQs are needed. If the LQs have Yukawa couplings solely to SM fermions, …
We review a novel model-independent approach to the analysis of new-physics effects in the $s\to u\ell^-\barν$ transitions. We apply it to (semi)leptonic kaon decays and study their complementarity with pion and hyperon $β$ decays or with collider searches of new physics.
Studying baryon number transport dynamics via hyperon-kaon correlations in $p + \mathrm{Au}$ collisions at $\sqrt{s_{_{\rm NN}}}=20$, $39$ and $62$ GeV
Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University（核物理与离子束应用教育部重点实验室，复旦大学）
Unraveling the Hyperon Puzzle in Neutron Stars via Novel, High-Precision Hyperon Factories
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；School of Physics and Astronomy, Tel Aviv University（特拉维夫大学物理与天文学学院）
Non-leptonic two-body weak decays of baryons are an important tool to probe the combined charge-conjugation--parity symmetry (CP) violation. We explain why the decays of strange baryons provide complementary information to the decays of kaons. A model-independent parameterization of the non-leptonic decays of the $Λ$- and $Ξ$-baryons is reviewed, and the amplitudes are updated according to the latest experimental input. We demonstrate the potential of performing precision tests in strange baryon decays at the next generation electron-positron $J/ψ$ factories with luminosity of $10^{35}$ cm$^{-…
Production of hyperon resonances induced by kaon on a deuteron target
从理论上研究了$K^- d \to πYN$反应，以研究$K^{-}$诱导的超子共振$Σ(1385)$和$Λ(1405)$的产生.为此，我们考虑介子-重子两体散射的p波振幅以及s波振幅。由于在该反应中从$\bar{K} N$通道选择性地产生超子共振的事实，$Λ(1405)$峰出现在1420 MeV处，这意味着在$K^{-} d \to n X$反应中发射的核子的丢失的质谱中可以分别看到$Λ(1405)$和$Σ(1385)$。本研究中的$πY$不变质谱与$Σ(1385)$和$Λ(1405)$的实验数据一致。的π交换贡献也包括在内，并发现给光滑的背景，而不扭曲的超子共振峰结构。
We investigate the potential of rare hyperon decays to probe the short distance structure in the $s\to dν\barν$ and $s\to d\ell^+\ell^-$ transitions. Hyperon decays into neutrinos ($B_1\to B_2ν\barν$) can be reliably predicted by using form factors determined in baryon chiral perturbation theory. Their decay rates are sensitive to different short-distance operators, as compared to their kaon counterparts, and the corresponding branching fractions are in the range of $10^{-14}\sim10^{-13}$ in the standard model. In the context of the low-energy effective theory, we find that the anticipated BES…
Rare kaon decays are excellent probes of light, new weakly-coupled particles. If such particles $X$ couple preferentially to muons, they can be produced in $K\to μνX$ decays. In this letter we evaluate the future sensitivity for this process at NA62 assuming $X$ decays either invisibly or to di-muons. Our main physics target is the parameter space that resolves the $(g-2)_μ$ anomaly, where $X$ is a gauged $L_μ-L_τ$ vector or a muon-philic scalar. The same parameter space can also accommodate dark matter freeze out or reduce the tension between cosmological and local measurements of $H_0$ if th…
在扭曲波脉冲近似下研究了准自由反应A $(γ, K Y)$ B.为此，我们提出了一个修正的树级模型的基本K介子光生，包括强子形状因子符合规范不变性，使用SU（3）的玻恩耦合值和使用共振符合多通道分析。独家准自由K介子光生核的潜力，揭示超子核相互作用的细节进行检查。对于所有六个产生通道，获得了符合截面、光子不对称性和超子极化及其对模型成分的敏感性的详细预测。在选定的运动学条件下，这些观测量对超子-核末态相互作用敏感。一些偏振观测量被发现是不敏感的失真的影响，使它们成为理想的工具，寻找可能的介质修改的基本振幅。
We study the thermal evolution of neutron stars in the presence of hyperons or kaons in the core. Our results indicate that the nucleon and hyperon direct Urca processes play crucial roles for the cooling of neutron stars. The presence of hyperons drives fast cooling mechanisms in two ways: 1) it allows the hyperon direct Urca prior to the nucleon direct Urca, 2) and it makes the nucleon direct Urca more feasible by reducing the neutron Fermi momentum. We found that the neutron star equation of state (EOS) with hyperons can be consistent with both mass and temperature observations. We also fou…
Despite not being designed for it, the LHCb experiment has given world-leading contributions in kaon and hyperon physics. In this contribution I review the prospects for kaon physics at LHCb exploiting the already acquired data and the current and future Upgrade scenarios.
The search for light and long-lived particles at the LHC will be intensified in the upcoming years with a prominent role of the new FASER experiment. In this study, we discuss how FASER could independently probe such scenarios relevant for new physics searches at kaon factories. We put an emphasis on the proposed explanations for the recently observed three anomalous events in the KOTO experiment. The baseline of FASER precisely corresponds to the proposed lifetime solution to the anomaly that avoids the NA62 bounds on charged kaons. As a result, the experiment can start constraining relevant …
We consider the strangeness-changing decays of hyperons into another baryon and missing energy which is carried away by a pair of invisible spinless bosons. Pursuing a model-independent approach and taking into account constraints from the kaon sector, we find that these hyperon modes can have large rates, especially if the bosons have parity-odd effective couplings to light quarks. In that case the rates could attain values which are well within the expected reach of the currently running BESIII experiment. Since the branching fractions of hyperon decays with missing energy are tiny in the st…
That massless dark photons could exist and have flavor-changing magnetic-dipole interactions with down-type light quarks is an attractive possibility which may be realized in various new-physics scenarios. It is potentially testable not only in kaon processes but also via two-body hyperon decays involving missing energy carried away by the massless dark photon. We explore the latter within a simplified model approach and take into account constraints from the kaon sector. We find that the branching fractions of some of these hyperon modes are allowed to be as high as a few times $10^{-4}$. Suc…
We explore kaon decays with missing energy carried away by a massless dark photon, $\barγ$, assumed to have flavor-changing dipole-type couplings to the $d$ and $s$ quarks. We consider in particular the neutral-kaon modes $K_L\toγ\barγ$ and $K_L\toπ^0γ\barγ$ and their $K_S$ counterparts, as well as the charged-kaon channel $K^+\toπ^+γ\barγ$, each of which also has an ordinary photon, $γ$, in the final state. In addition, we look at $K_{L,S}\toπ^+π^-\barγ$ and $K^+\toπ^+π^0\barγ$. Interestingly, the same $ds\barγ$ interactions give rise to the flavor-changing two-body decays of hyperons with mi…
Hyperon production in near threshold nucleon-nucleon collisions
为了理解COSY-11合作组最近公布的pp --> p λ K+和pp --> p σ 0 K+反应的新数据，我们在有效拉格朗日模型下，研究了核子-核子碰撞中在更大的阈能范围内产生λ-k介子和σ-k介子的机制.在这个理论中，超子的产生是通过N*（1650）、N*（1710）和N*（1720）重子共振的激发进行的。各种共振的相对贡献的相互作用的截面，讨论了作为一个功能的光束能量在一个更大的近阈值能量域。给出了pp --> p Sigma+ K ~ 0，pp --> n Sigma+K ~+和pn --> n Lambda K ~+反应总截面的预测.
We present a concise overview on $CP$ violation in hyperon decays, including past, present, and future efforts to search for it. We highlight in particular the most recent results of the BESIII experiment using a quantum-entangled pair of hyperon and antihyperon produced by a charmonium resonance formed in $e^+e^-$ annihilation. The subsequent nonleptonic decays of these hyperon pairs allow for the simultaneous determination of various parameters pertaining to $CP$ violation in the decays. We compare the reported data with the corresponding current predictions for $CP$ asymmetries within the s…
Studies of lepton-flavor violation in strangeness-changing ($|ΔS|=1$) transitions have a~long tradition in the kaon sector where they provide some of the strongest limits on physics beyond the standard model. Recent hints of violation of lepton-flavor universality in $B$-meson decays have revived interest in lepton-flavor violation as the two phenomena appear simultaneously in many extensions of the standard model. At the same time, the LHCb experiment has produced new results for the hyperon process $Σ^+\to pμ^+μ^-$ and may be in a position to study other rare hyperon decay modes. With this i…
Spin polarization and entanglement are utilized by the BESIII experiment to learn more about the production and decay properties of hyperon-antihyperon pairs in a series of recent analyses of its unprecedented datasets at the $J/ψ$ and $ψ'$ resonances. This has lead to the observation of significant transverse polarisation in decays of $J/ψ$ or $ψ'$ into $Λ\barΛ$, $Σ\barΣ$, $Ξ\barΞ$, and $Ω\barΩ$. Because of the non-zero polarization, the decay parameters for the most common hadronic weak decays of both hyperons and antihyperons could be determined independently for the first time. Comparing t…
Dark sector particles at the GeV scale carrying baryon number provide an attractive framework for understanding the origin of dark matter and the matter-antimatter asymmetry of the universe. We demonstrate that dark decays of hadronic states containing strange quarks -- hyperons -- offer excellent prospects for discovering such dark baryons. Building up on novel calculations of the matrix elements relevant for hyperon dark decays, and in view of various collider, flavor, and astrophysical constraints, we determine the expected rates at hyperon factories like BESIII and LHCb. We also highlight …
The two kaon factories, KOTO and NA62, are at the cutting edge of the intensity frontier, with an unprecedented numbers of long lived and charged Kaons, ~ 10^{13}, being measured and analyzed. These experiments have currently a unique opportunity to search for dark sectors. In this paper, we demonstrate that searches done at KOTO and NA62 are complementary, both probing uncharted territories. We consider two qualitatively different physics cases. In the first, we analyze models of axion-like-particles (ALP) which couple to gluons or electroweak gauge bosons. In the second, we introduce a model…
We explore the strangeness-changing decays of the lightest hyperons into another baryon plus missing energy within and beyond the standard model (SM). In the SM these processes arise from the loop-induced quark transition $s\to dν\barν$ and their branching fractions are estimated to be less than $10^{-11}$. In the presence of new physics (NP) the rates of these hyperon decays with missing energy could increase significantly with respect to the SM expectations because of modifications to the SM process or contributions from additional modes with new invisible particles. Adopting a model-indepen…
The three electromagnetic form factors for the transition from a 3/2+ Sigma* hyperon to the ground-state Lambda hyperon are studied. At low energies, combinations of the transition form factors can be deduced from Dalitz decays of the Sigma* hyperon to Lambda plus an electron-positron pair. It is pointed out how more information can be obtained with the help of the self-analyzing weak decay of the Lambda. In particular it is shown that these transition form factors are complex quantities already in this kinematical region. Such measurements are feasible at hyperon factories as for instance the…
