共查询到20条相似文献,搜索用时 0 毫秒
1.
Recent results from the Advanced Thin Ionization Calorimeter (ATIC) balloon experiment have identified the presence of a spectral feature between approximately 300 and 800 GeV in the cosmic ray electron spectrum. This spectral feature appears to imply the existence of a local (1 kpc) source of high energy electrons. Emission from a local pulsar and dark matter annihilations have each been put forth as possible origins of this signal. In this Letter, we consider the sensitivity of ground based atmospheric Cherenkov telescopes to electrons and show that observatories such as HESS and VERITAS should be able to resolve this feature with sufficient precision to discriminate between the dark matter and pulsar hypotheses with considerably greater than 5σ significance, even for conservative assumptions regarding their performance. In addition, this feature provides an opportunity to perform an absolute calibration of the energy scale of ground based, gamma ray telescopes. 相似文献
2.
R-violating decay of Wino dark matter and electron/positron excesses in the PAMELA/Fermi experiments
We show that R-parity violating decay of Wino dark matter of mass about 3 TeV can naturally account for the flux and spectral shape of the cosmic-ray electrons and positrons observed by the PAMELA and Fermi satellites. To provide a theoretical basis for the scenario, we present a model in which trilinear R-parity breaking appears with a coefficient suppressed by powers of the gravitino mass, which naturally leads to the Wino lifetime of O(1026) seconds. 相似文献
3.
Taking into account effects of late energy injection, we examine big bang nucleosynthesis (BBN) constraints on axino dark matter scenarios with long-lived charged sleptons. We calculate 4-body slepton decays into the axino, a lepton, and a quark–antiquark pair since they govern late hadronic energy injection and associated BBN constraints. For supersymmetric hadronic axion models, we present the obtained hadronic BBN constraints and show that they can be more restrictive than the ones associated with catalyzed BBN via slepton-bound-state formation. From the BBN constraints on hadronic and electromagnetic energy release, we find new upper limits on the Peccei–Quinn scale. 相似文献
4.
We study the recent e±cosmic ray excess reported by DAMPE in a Hidden Valley Model with lepton-portal dark matter. We find the electron-portal can account for the excess well and satisfy the DM relic density and direct detection bounds, while electron+muon/electron+muon+tau-portal suffers from strong constraints from lepton flavor violating observables, such as μ→3 e. We also discuss possible collider signatures of our model, both at the LHC and a future 100 Te V hadron collider. 相似文献
5.
Yu. F. Pirogov 《Physics of Atomic Nuclei》2007,70(12):2148-2151
The minimal metagravity theory, explicitly violating the general covariance but preserving the unimodular one, is applied
to study the evolution of the isotropic homogeneous Universe. The massive scalar graviton, contained in the theory in addition
to the massless tensor one, is treated as a source of dark matter and/or dark energy. The modified Friedmann equation for
the scale factor of the Universe is derived. The question whether the minimal metagravity can emulate the LCDM concordance
model, valid in General Relativity, is discussed.
The text was submitted by the author in English. 相似文献
6.
Confronting cosmic ray electron and positron excesses with hybrid triplet Higgs portal dark matter 下载免费PDF全文
We perform a detailed study of scalar dark matter with triplet Higgs extensions of the Standard Model in order to explain the cosmic ray electron and positron excesses reported by AMS-02 and DAMPE. A detailed analysis of the AMS-02 positron excess reveals that for different orderings (normal, inverted, and quasi-degenerate) of neutrino mass, the hybrid triplet Higgs portal framework is more favored with respect to the single triplet Higgs portal for TeV scale dark matter. We also show that the resonant peak and continuous excess in DAMPE cosmic ray data can be well explained with the hybrid triplet Higgs portal dark matter when a dark matter sub-halo nearby is taken into account. 相似文献
7.
Highly accurate measurements of cosmic ray electron flux by the dark matter particle explorer(DAMPE) ranging between 25 Ge V and 4.6 Te V have recently been published. A sharp peak structure was found at ~ 1.4 Te V. This unexpected peak structure can be reproduced by the annihilation/decay of a nearby dark matter(DM) halo. In this study, we adopt the decaying-DM model to interpret the ~ 1.4 Te V peak. We found that the decay products of the local DM subhalo could contribute to the DMAPE peak with mDM= 3 Te V and τ~ 10~(28) s. We also obtain constraints on DM lifetime and the distance of the local DM subhalo by comparison with DAMPE data. 相似文献
8.
A small difference between the energies of the para-positronium (p-Ps) and ortho-positronium (o-Ps) states suggests the possibility of the superposition of p-Ps and o-Ps during the formation of positronium (Ps) from pre-Ps, terminating its migration in the matter in a void. It is shown that such a superposition decoheres in the basis of p-Ps and o-Ps. The decoherence time scale estimated here motivates a correction in the precise analysis of the positron annihilation lifetime spectra. More generally, the superposited Ps state should contribute to the theory of the evolution of positronium in matter. 相似文献
9.
10.
T. E. Jackman P. C. Lichtenberger C. W. Schulte 《Applied Physics A: Materials Science & Processing》1974,5(3):259-264
The development of computer programmes to deconvolute and fit the Dopplerbroadened annihilation radiation from a moving positron-electron pair is discussed. An analysis is presented for the annihilation line observed in a series of metals using a high-resolution Ge(Li) detector. 相似文献
11.
12.
A.A Manuel R Sachot P Descouts M Peter R.M Singru A.K Singh 《Solid State Communications》1983,45(9):799-801
The angular correlation of the positron annihilation radiation has been measured with a bidimensional apparatus in four planes of V single crystals. The results are compared with calculations of the electron- positron momentum distribution and with theoretical Fermi surface. 相似文献
13.
14.
15.
Mubasher Jamil Muneer Ahmad Rashid 《The European Physical Journal C - Particles and Fields》2009,60(1):141-147
We have investigated constraints on the coupling between dark matter and the interacting Chaplygin gas. Our results indicate
that the coupling constant c between these two entities can take arbitrary values, which can be either positive or negative, thus giving arbitrary freedom
to the inter-conversion between Chaplygin gas and dark matter. Thus, our results indicate that the restriction 0<c<1 on the coupling constant occurs as a very special case. Our analysis also supports the existence of phantom energy under
certain conditions on the coupling constant. 相似文献
17.
Motivated by the anomalous positron flux recently reported by the PAMELA Collaboration, we study the cosmic-ray positron produced by the pair annihilation and the decay of superparticle dark matter. We calculate the cosmic-ray positron flux and discuss implications of the PAMELA data. We show that the positron excess observed by the PAMELA can be explained with some of the superparticle dark matter. 相似文献
18.
19.
Ch. Berger W. Lackas F. Raupach W. Wagner G. Alexander L. Criegee H.C. Dehne K. Derikum R. Devenish G. Flügge G. Franke Ch. Gerke E. Hackmack P. Harms G. Horlitz Th. Kahl G. Knies K. Wacker 《Physics letters. [Part B]》1978,78(1):176-182
From an analysis of data taken with the detector PLUTO and the DORIS storage rings we have obtained evidence for jet structure in e+e? annihilation with hadrons. Results for mean sphericity, mean thrust, the angular dependence of the jet axis and for 〈pt〉 and 〈p∥〉 with respect to the jet axis are presented. At 9.4 GeV we also discuss the angular dependence of the charged and neutral deposited energy with respect to the jet axis. 相似文献
20.
We propose a model based on a DBI action for the unification of dark matter and dark energy. This is supported by the results of the study of its background behavior at early and late times, and reinforced by the analysis of the evolution of perturbations. We also perform a Bayesian analysis to set observational constraints on the parameters of the model using type Ia SN, CMB shift and BAO data. Finally, to complete the study we investigate its kinematics aspects, such as the effective equation of state parameter, acceleration parameter and transition redshift. Particularizing those parameters for the best fit one appreciates that an effective phantom is preferred. 相似文献