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M. A. Nikolaev H. V. Klapdor-Kleingrothaus 《Zeitschrift für Physik A Hadrons and Nuclei》1993,345(4):373-376
We present calculations of the quenching of the spin-dependent elastic scattering cross section for dark matter WIMPs on heavy nuclei. The theory of finite Fermi systems was used to describe the behavior of the nuclear spin matrix elements in the nuclear medium. The results of the calculations for planned dark matter detector nuclei are not only always smaller than corresponding single particle estimations but in some cases also differ from the ones obtained by using measured nuclear magnetic moments.One of the authors (M.A.N.) wants to thank the Max-Planck-Institut für Kernphysik (Heidelberg, Germany) for the hospitality during the time in which this work was carried out, and the Deutscher Akademischer Austauschdienst (DAAD) for financial support. 相似文献
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M. A. Nikolaev H. V. Klapdor-Kleingrothaus 《Zeitschrift für Physik A Hadrons and Nuclei》1993,345(2):183-186
We present calculations of the nuclear from factors for spin-dependent elastic scattering of dark matter WIMPs from123Te and131Xe isotopes, proposed to be used for dark matter detection. A method based on the theory of finite Fermi systems was used to describe the reduction of the single-particle spin-dependent matrix elements in the nuclear medium. Nucleon single-particle states were calculated in a realistic shell model potential; pairing effects were treated within the BCS model. The coupling of the lowest single-particle levels in123Te to collective 2+ excitations of the core was taken into account phenomenologically. The calculated nuclear form factors are considerably less then the single-particle ones for low momentum transfer. At high momentum transfer some dynamical amplification takes place due to the pion exchange term in the effective nuclear interaction. But as the momentum transfer increases, the difference disappears, the momentum transfer increases and the quenching effect disappears. The shape of the nuclear form factor for the131Xe isotope differs from the one obtained using an oscillator basis. 相似文献
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V.P. Mikhailyuk 《The European Physical Journal A - Hadrons and Nuclei》2000,9(4):473-477
The differential cross-section for elastic scattering of deuterons at 700 MeV, 6Li and 6He at 2.07 GeV nuclei on 12C nucleus is calculated under the assumption of two-cluster (for deuterons and 6Li) and three-cluster (for 6He) structure of incident particle. For 6Li-12C and 6He-12C elastic scattering it is shown that there are quantitative distinctions in the behaviour of the observables calculated in
the above approaches.
Received: 13 October 1999 / Accepted: 3 January 2001 相似文献
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We investigate a new class of dark matter: superweakly interacting massive particles (super-WIMPs). As with conventional WIMPs, super-WIMPs appear in well motivated particle theories with naturally the correct relic density. In contrast to WIMPs, however, super-WIMPs are impossible to detect in all conventional dark matter searches. We consider the concrete examples of gravitino and graviton cold dark matter in models with supersymmetry and universal extra dimensions, respectively, and show that super-WIMP dark matter satisfies stringent constraints from big bang nucleosynthesis and the cosmic microwave background. 相似文献
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Kim SC Bhang H Choi JH Kang WG Kim BH Kim HJ Kim KW Kim SK Kim YD Lee J Lee JH Lee JK Lee MJ Lee SJ Li J Li J Li XR Li YJ Myung SS Olsen SL Ryu S Seong IS So JH Yue Q;KIMS Collaboration 《Physical review letters》2012,108(18):181301
New limits are presented on the cross section for weakly interacting massive particle (WIMP) nucleon scattering in the KIMS CsI(T?) detector array at the Yangyang Underground Laboratory. The exposure used for these results is 24?524.3 kg·days. Nuclei recoiling from WIMP interactions are identified by a pulse shape discrimination method. A low energy background due to alpha emitters on the crystal surfaces is identified and taken into account in the analysis. The detected numbers of nuclear recoils are consistent with zero and 90% confidence level upper limits on the WIMP interaction rates are set for electron equivalent energies from 3 to 11 keV. The 90% upper limit of the nuclear recoil event rate for 3.6-5.8 keV corresponding to 2-4 keV in NaI(T?) is 0.0098 counts/kg/keV/day, which is below the annual modulation amplitude reported by DAMA. This is incompatible with interpretations that enhance the modulation amplitude such as inelastic dark matter models. We establish the most stringent cross section limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses greater than 20 GeV/c2. 相似文献
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There is increasing evidence that conventional cold dark matter (CDM) models lead to conflicts between observations and numerical simulations of dark matter halos on subgalactic scales, which rules out the favored candidates for CDM, namely weakly interacting massive particles (WIMPs). We propose a mechanism of nonthermal production of WIMPs and study its implications on the power spectrum. Our results show that, in this context, WIMPs as candidates for dark matter can work well both on large scales and on subgalactic scales. 相似文献
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Gallas E Abolins M Brock R Cobau WG Hatcher RW Owen DP Perkins GJ Tartaglia M Weerts H Bogert D Fuess S Koizumi G Stutte L Friedman JI Kendall HW Kistiakowsky V Lyons T Osborne LS Pitt R Rosenson L Schneekloth U Strongin B Taylor FE Walker JK White A Womersley WJ 《Physical review D: Particles and fields》1995,52(1):6-14
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We study the prospects for detecting weakly interacting massive particles (WIMPs) in a number of phenomenological scenarios, with a detector composed of a target simultaneously sensitive to both spin-dependent and spin-independent couplings, as is the case of COUPP (Chicagoland Observatory for Underground Particle Physics). First, we show that sensitivity to both couplings optimizes chances of initial WIMP detection. Second, we demonstrate that, in case of detection, a comparison of the signal on two complementary targets, such as in COUPP CF3I and C4F10 bubble chambers, allows a significantly more precise determination of the dark matter axial and scalar couplings. This strategy would provide crucial information on the nature of the WIMPs and possibly allow discrimination between neutralino and Kaluza-Klein dark matter. 相似文献
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Lee HS Bhang HC Choi JH Dao H Hahn IS Hwang MJ Jung SW Kang WG Kim DW Kim HJ Kim SC Kim SK Kim YD Kwak JW Kwon YJ Lee J Lee JH Lee JI Lee MJ Lee SJ Li J Li X Li YJ Myung SS Ryu S So JH Yue Q Zhu JJ;KIMS Collaboration 《Physical review letters》2007,99(9):091301
The Korea Invisible Mass Search (KIMS) experiment presents new limits on the weakly interacting massive particle (WIMP)-nucleon cross section using data from an exposure of 3409 kg.d taken with low-background CsI(Tl) crystals at the Yangyang Underground Laboratory. The most stringent limit on the spin-dependent interaction for a pure proton case is obtained. The DAMA signal region for both spin-independent and spin-dependent interactions for the WIMP masses greater than 20 GeV/c2 is excluded by the single experiment with crystal scintillators. 相似文献
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P. Hut 《Physics letters. [Part B]》1977,69(1):85-88
Limits on the masses and number of neutral weakly interacting particles are derived using cosmological arguments. No such particles with a mass between 120 eV and 3 GeV can exist within the usual big band model. Similar, but much more severe, restrictions follow for particles that interact only gravitationally. This seems of importance with respect to supersymmetric theories. 相似文献
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Akerib DS Attisha MJ Bailey CN Baudis L Bauer DA Brink PL Brusov PP Bunker R Cabrera B Caldwell DO Chang CL Cooley J Crisler MB Cushman P Daal M Dixon R Dragowsky MR Driscoll DD Duong L Ferril R Filippini J Gaitskell RJ Golwala SR Grant DR Hennings-Yeomans R Holmgren D Huber ME Kamat S Leclercq S Lu A Mahapatra R Mandic V Meunier P Mirabolfathi N Nelson H Nelson R Ogburn RW Perera TA Pyle M Ramberg E Rau W Reisetter A Ross RR Sadoulet B Sander J Savage C Schnee RW Seitz DN Serfass B 《Physical review letters》2006,96(1):011302
We report new results from the Cryogenic Dark Matter Search (CDMS II) at the Soudan Underground Laboratory. Two towers, each consisting of six detectors, were operated for 74.5 live days, giving spectrum-weighted exposures of 34 (12) kg d for the Ge (Si) targets after cuts, averaged over recoil energies 10-100 keV for a weakly interacting massive particle (WIMP) mass of 60 GeV/c2. A blind analysis was conducted, incorporating improved techniques for rejecting surface events. No WIMP signal exceeding expected backgrounds was observed. When combined with our previous results from Soudan, the 90% C.L. upper limit on the spin-independent WIMP-nucleon cross section is 1.6 x 10(-43) cm2 from Ge and 3 x 10(-42) cm2 from Si, for a WIMP mass of 60 GeV/c2. The combined limit from Ge (Si) is a factor of 2.5 (10) lower than our previous results and constrains predictions of supersymmetric models. 相似文献
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《Nuclear Physics A》1996,609(3):391-410
The contribution of mesonic exchange currents to nuclear Compton scattering is investigated within the framework of a Fermi gas model of nuclear matter in the non-relativistic limit. The additional interaction between the nucleons is accounted for by including two- and three-body diagrams. As a test of this model, the enhancement constant κ is calculated. The full correlators for the central and tensor parts of the nucleon-nucleon interaction due to pion exchange are obtained and the energy dependence of the amplitude is investigated. The contribution of the Δ-excitation to the mesonic part of the Compton amplitude is calculated explicitly using an effective Hamiltonian in the static limit. 相似文献