中性伴子暗物质（或其他暗物质候选者）的湮灭产生电子和正电子，以及其他标准模型态。这些粒子由于与银河磁场相互作用而发射出同步加速器光子。在这封信中，我们使用WMAP卫星的测量来限制这种同步辐射的强度，反过来，最轻的中性伴子的湮灭截面。我们发现这个约束比任何其他当前间接检测通道所提供的约束更严格。特别是，对于能量为100 GeV（500 GeV）的中性伴子，中性伴子湮灭的截面必须小于~ 3 x 10^-26 cm ^3/s（1 x 10^25 cm ^3/s）。对于银河系内部8千秒差距内完全平坦的暗物质分布的保守情况，约束的严格性大约是30倍。即使在这种保守的情况下，同步加速器的测量也强烈限制了早期宇宙中非热产生wino或higgsino中性伴子暗物质的可能性。
英文摘要：
The annihilations of neutralino dark matter (or other dark matter candidate) generate, among other Standard Model states, electrons and positrons. These particles emit synchrotron photons as a result of their interaction with the Galactic Magnetic Field. In this letter, we use the measurements of the WMAP satellite to constrain the intensity of this synchrotron emission and, in turn, the annihilation cross section of the lightest neutralino. We find this constraint to be more stringent than that provided by any other current indirect detection channel. In particular, the neutralino annihilation cross section must be less than ~ 3 x 10^-26 cm^3/s (1 x 10^25 cm^3/s) for 100 GeV (500 GeV) neutralinos distributed with an NFW halo profile. For the conservative case of an entirely flat dark matter distribution within the inner 8 kiloparsecs of the Milky Way, the constraint is approximately a factor of 30 less stringent. Even in this conservative case, synchrotron measurements strongly constrain, for example, the possibility of wino or higgsino neutralino dark matter produced non-thermally in the early universe.
We consider a scenario inspired by natural supersymmetry, where neutrino data is explained within a low-scale seesaw scenario. We extend the Minimal Supersymmetric Standard Model by adding light right-handed neutrinos and their superpartners, the R-sneutrinos, and consider the lightest neutralinos to be higgsino-like. We consider the possibilities of having either an R-sneutrino or a higgsino as lightest supersymmetric particle. Assuming that squarks and gauginos are heavy, we systematically evaluate the bounds on slepton masses due to existing LHC data.
Synchrotron self-Compton process for constraining sub-GeV dark matter in Omega Centauri via SKA
Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台暗物质与空间天文重点实验室）；School of Astronomy and Space Science, University of Science and Technology of China（中国科学技术大学天文与空间科学学院）
Dark Matter (DM) annihilation in our Galaxy may produce a linearly polarized synchrotron signal. We use, for the first time, synchrotron polarization to constrain the DM annihilation cross section by comparing theoretical predictions with the latest polarization maps obtained by the Planck satellite collaboration. We find that synchrotron polarization is typically more constraining than synchrotron intensity by about one order of magnitude, independently of uncertainties in the modeling of electron and positron propagation, or of the Galactic magnetic field. Our bounds compete with Cosmic Micr…
Constraining the Charged Higgs Mass in the MSSM: A Low-Energy Approach
我们研究了最小超对称标准模型中带电希格斯玻色子质量的当前下界。通过对中性希格斯玻色子玻色子和其他超对称态施加直接搜索约束，以及一些间接约束（b -> s gamma，B_s -> mu mu，B -> tau nu，B -> D tau nu），我们发现有可能将带电希格斯玻色子玻色子的质量推低至140 GeV。我们工作在一个完全低能量的方法，没有假设标量质量统一，检查两个最流行的限制中性希格斯玻色子搜索：最大混合和无混合的情况。虽然这两种情况都允许轻带电的希格斯玻色子玻色子，但它们的tan（β）范围完全不同。在这两种情况下，人们都期望轻顶方子伴随着轻荷希格斯粒子。
Supersymmetric models with Dirac instead of Majorana gaugino masses have distinct phenomenological consequences. In this paper, we investigate the electroweakino sector of the Minimal Dirac Gaugino Supersymmetric Standard Model (MDGSSM) with regards to dark matter (DM) and collider constraints. We delineate the parameter space where the lightest neutralino of the MDGSSM is a viable DM candidate, that makes for at least part of the observed relic abundance while evading constraints from DM direct detection, LEP and lowenergy data, and LHC Higgs measurements. The collider phenomenology of the th…
Considering the supersymmetric model with the long-lived charged Higgsino, we discuss how Higgsino kink signals can show up in the latest LHC Disappearing Track (DT) and stable chargino searches. We derive constraints on the Higgsino kink signal, and characterize it in comparison to the Wino DT and the slepton kink track. We also discuss how to infer Higgsino model kinematics.
We find new limits on the $λ'_{3jk}$ R-parity violating (RPV) couplings of the minimal supersymmetric standard model, using Drell-Yan differential cross sections at the LHC and electroweak precision measurements from LEP and SLC. Specifically, limits on six out of the nine $λ'_{3jk}$-couplings, with $j=1\text{ or }2$, are obtained using Drell-Yan data, with the remaining three (for $j=3$) bounded by precision electroweak data. We also update the limits on all $λ'_{ijk}$-couplings using electroweak data and find new bounds on $λ'_{132}$ and $λ'_{232}$ that are stronger than obtained elsewhere. …
This work deals with right handed sneutrino as thermal cold dark matter candidate. This scalar emerges in a supersymmetric version of $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$ gauge model where right handed neutrinos are a natural component of leptonic chiral scalar supermultiplets. We first consider the issue of a $125$~GeV Higgs boson mass in this model, showing that constraints on stop mass and trilinear soft coupling are considerably alleviated compared to MSSM. Then we investigate the region of parameter space that is consistent with right handed sneutrino as thermal cold dark matter, unde…
In the Minimal Supersymmetric Standard Model light neutralinos can satisfy the dark matter (DM) abundance constraint by resonant annihilation via a $Z$ or a light Higgs ($h$) boson. In this work we study the current and future status of this scenario by investigating relevant experimental constraints, including DM direct detection, measurements of $Z$ and Higgs invisible decays, and direct searches at the Large Hadron Collider (LHC). To take full advantage of the LHC data, we combine the results of all relevant electroweakino searches performed by the Compact Muon Solenoid (CMS) Collaboration.…
We use the Higgs coupling and the muon anomalous magnetic moment measurements to constrain the parameter space of the natural supersymmetry (SUSY) in the Generalized Minimal Supergravity (GmSUGRA) model. We scan the parameter space of the GmSUGRA model with small electroweak fine-tuning measure ($Δ_{\rm EW} \leq 100$). The parameter space after applying various sparticle mass bounds, Higgs mass bounds, B-physics bounds, the muon magnetic moment constraint, and the Higgs coupling constraint from measurements at HL-LHC, ILC, and CEPC, is shown in the planes of various interesting model parameter…
A period of early matter domination can give rise to the correct dark matter abundance for a broad range of dark matter annihilation rate $\langle σ_{\rm ann} v \rangle_{\rm f}$. Here, we examine this scenario for situations where $\langle σ_{\rm ann} v \rangle_{\rm f}$ is below the nominal value for thermal dark matter $3 \times 10^{-26}$ cm$^3$ s$^{-1}$ as possibly indicated by some recent experiments. We show that obtaining the correct relic abundance sets a lower bound on the duration of early matter domination era in this case. On the other hand, provided that the post-inflationary univer…
We revisit the hybrid inflation model gauged by $U(1)_{B-L}$ extension of the Minimal Supersymmetric Standard Model (MSSM) in a no-scale background. Considering a single predictive framework, we study inflation, leptogenesis, gavitino cosmology, and the stochastic background of gravitational waves produced by metastable cosmic strings. The spontaneous breaking of $U(1)_{B-L}$ at the end of inflation produces a network of metastable cosmic strings while, the interaction between $U(1)_{B-L}$ Higgs field and the neutrinos generate heavy Majorana masses for the right-handed neutrinos. The heavy Ma…
We study the potential of the Square Kilometre Array in the first phase (SKA1) in detecting dark matter annihilation signals from dwarf spheroidals in the form of diffuse radio synchrotron. Taking the minimal supersymmetric standard model as illustration, we show that it is possible to detect such signals for dark matter masses about an order of magnitude beyond the reach of the Large Hadron Collider, with about 100 hours of observation with the SKA1.
