Using the latest AMS-02 cosmic ray antiproton flux data, we search for potential dark matter annihilation signal. The background parameters about the propagation, source injection, and solar modulation are not assumed a priori, but based on the results inferred from the recent B/C ratio and proton data measurements instead. The possible dark matter signal is incorporated into the model self-consistently under a Bayesian framework. Compared with the astrophysical background only hypothesis, we find that a dark matter signal is favored. The rest mass of the dark matter particles is ∼ 20 − 80 GeV and the velocity-averaged hadronic annihilation cross section is about (0.2 − 5) × 10 −26 cm 3 s −1 , in agreement with that needed to account for the Galactic center GeV excess and/or the weak GeV emission from dwarf spheroidal galaxies Reticulum 2 and Tucana III. Tight constraints on the dark matter annihilation models are also set in a wide mass region. PACS numbers: 95.35.+d,Introduction -The precise measurements of cosmic ray (CR) anti-particle spectra by space-borne instruments, such as PAMELA and AMS-02, provide very good sensitivity to probe the particle dark matter (DM) annihilation or decay in the Milky Way. The CR antiprotons, primarily come from the inelastic collisions between the CR protons (and Helium) and the interstellar medium (ISM), are effective to constrain the DM models [1][2][3]. Recent observations of the antiproton fluxes [4][5][6] are largely consistent with the expectation from the CR propagation model, leaving very limited room for the annihilation or decay of DM [2,[7][8][9][10].There are several sources of uncertainties in using antiprotons to constrain DM models. The largest uncertainty may come from the propagation parameters. Usually the secondary-to-primary ratio of CR nuclei, such as the Boronto-Carbon ratio (B/C), and the radioactive-to-stable isotope ratio of secondary nuclei, such as the Beryllium isotope ratio 10 Be/ 9 Be, are used to determine the propagation parameters [11,12]. Limited by the data quality, the constraints on the propagation parameters are loose [13,14]. Even the effect on the background antiproton flux due to uncertainties of propagation parameters is moderate, the flux from the DM component depends sensitively on propagation parameters [15]. Additional uncertainties include the injection spectrum of the CR nuclei, solar modulation, and hadronic interaction models [8]. Those uncertainties make the DM searches with antiprotons inconclusive [16,17].Given the new measurements of the proton, Helium, and B/C data by , improved constraints on the propagation and source injection parameters can be obtained through global Bayesian approaches [22][23][24][25]. With these data, we conduct a global study to determine the propagation, injection, and solar modulation parameters si- * The corresponding author: yuanq@pmo.ac.cn † The corresponding author: yzfan@pmo.ac.cn multaneously using the Markov Chain Monte Carlo (MCMC) method [26]. These "background" parameters and their like...
In light of the recent discovery by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) of a Higgs-like particle with a narrow mass range of 125–126 GeV, we perform an updated analysis on one of the popular scalar dark matter models, the Inert Higgs Doublet Model (IHDM). We take into account in our likelihood analysis of various experimental constraints, including recent relic density measurement, dark matter direct and indirect detection constraints as well as the latest collider constraints on the invisible decay width of the Higgs boson and monojet search at the LHC. It is shown that if the invisible decay of the standard model Higgs boson is open, LHC as well as direct detection experiments like LUX and XENON100 could put stringent limits on the Higgs boson couplings to dark matter. We find that the most favoured parameter space for IHDM corresponds to dark matter with a mass less than 100 GeV or so. In particular, the best-fit points are at the dark matter mass around 70 GeV where the invisible Higgs decay to dark matter is closed. Scalar dark matter in the higher mass range of 0.5–4 TeV is also explored in our study. Projected sensitivities for the future experiments of monojet at LHC-14, XENON1T and AMS-02 one year antiproton flux are shown to put further constraints on the existing parameter space of IHDM.
We present an updated and extended global analysis of the Constrained MSSM (CMSSM) taking into account new limits on supersymmetry from ∼ 5/fb data sets at the LHC. In particular, in the case of the razor limit obtained by the CMS Collaboration we simulate detector efficiency for the experimental analysis and derive an approximate but accurate likelihood function. We discuss the impact on the global fit of a possible Higgs boson with mass near 125 GeV, as implied by recent data, and of a new improved limit on BR Bs → µ + µ − . We identify high posterior probability regions of the CMSSM parameters as the stau-coannihilation and the A-funnel region, with the importance of the latter now being much larger due to the combined effect of the above three LHC results and of dark matter relic density. We also find that the focus point region is now disfavored. Ensuing implications for superpartner masses favor even larger values than before, and even lower ranges for dark matter spin-independent cross section, σ SI p ∼ < 10 −9 pb. We also find that relatively minor variations in applying experimental constraints can induce a large shift in the location of the best-fit point. This puts into question the robustness of applying the usual χ 2 approach to the CMSSM. We discuss the goodness-of-fit and find that, while it is difficult to calculate a p-value, the (g − 2)µ constraint makes, nevertheless, the overall fit of the CMSSM poor. We consider a scan without this constraint, and we allow µ to be either positive or negative. We find that the global fit improves enormously for both signs of µ, with a slight preference for µ < 0 caused by a better fit to BR (b → sγ) and BR Bs → µ + µ − .
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