Journal articles: 'Particle darō'

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Takibayev, N. "Models of dark particle interactions with ordinary matter." Physical Sciences and Technology 2, no. 2 (2015): 58–69. http://dx.doi.org/10.26577/2409-6121-2015-2-2-58-69.

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Tang, Yong. "Interacting dark matter and dark radiation." Modern Physics Letters A 32, no. 15 (April 11, 2017): 1740006. http://dx.doi.org/10.1142/s0217732317400065.

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We give a brief review on the interacting Dark Matter (iDM) scenario and its effects on cosmology and particle physics. If DM candidates can have strong self-interactions or interactions with other relativistic particles, we can refer them generally as iDM. IDM is an interesting possibility that is motivated both theoretically and observationally. The relativistic particles could belong to Standard Model (SM), such as photons and neutrinos, or be dark radiation (DR) in new physics. The resulting perturbed Boltzmann equations are concisely discussed and illustrations on matter power spectrum are given.

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Khlopov, Maxim. "Dark atoms and puzzles of dark matter searches." International Journal of Modern Physics A 29, no. 19 (July 30, 2014): 1443002. http://dx.doi.org/10.1142/s0217751x14430027.

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The nonbaryonic dark matter of the universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and particle candidates for cosmological dark matter are the lightest particles that bear new conserved quantum numbers. Dark matter candidates can appear in the new families of quarks and leptons and the existence of new stable charged leptons and quarks is possible, if they are hidden in elusive "dark atoms." Such possibility, strongly restricted by the constraints on anomalous isotopes of light elements, is not excluded in scenarios that predict stable double charged particles. The excessive -2 charged particles are bound in these scenarios with primordial helium in O -helium "atoms," maintaining specific nuclear-interacting form of the dark matter, which may provide an interesting solution for the puzzles of the direct dark matter searches.

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Vladimir, Kuksa. "Hadronic Dark Matter." EPJ Web of Conferences 222 (2019): 04001. http://dx.doi.org/10.1051/epjconf/201922204001.

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The possibility of hadronic Dark Matter particles is analised in the framework of the simplest extensions of the Standard Model. Hadronic particles possess strong interaction and consist of new heavy quark and light standard one. It is shown that the existence of heavy quarks does not contradict to the precision electro-weak restrictions on new physics. The neutral and charged pseudoscalar low-lying heavy states are considered as the Dark Matter particle and its mass-degenerated partner. We evaluated the values of their masses and lifetime of the charged component. The potential of low-energy interactions of these particles with nucleons is described in the framework of the exchangemeson model. Some peculiarities of the hadronic Dark Matter scenario are also discussed.

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KIM, HANG BAE. "SIGNALS FOR LIGHT DARK MATTER AXINO." Modern Physics Letters A 22, no. 25n28 (September 14, 2007): 2113–20. http://dx.doi.org/10.1142/s0217732307025364.

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Light dark matter aims at explaining the 511 keV γ-ray line emission from the galactic bulge as well as cold dark matter in our universe. The former is achieved via the annihilations or decays of light dark matter particles, which implies interesting observational consequences in addition to 511 keV γ-rays. We consider the axino in the 1 ~ 10 MeV mass range as the light dark matter particle and discuss the particle physics models for it, its cosmological production, and its decay arising from R-parity violation. For additional observational signals, we consider the connection to the neutrino data made by bilinear R-parity violations and the continuum γ-ray emission from light dark matter particles.

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Khlopov, Maxim. "Cosmoparticle physics of dark matter." EPJ Web of Conferences 222 (2019): 01006. http://dx.doi.org/10.1051/epjconf/201922201006.

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The lack of confirmation for the existence of supersymmetric particles and Weakly Interacting Massive Particles (WIMPs) appeals to extension of the field of studies of the physical nature of dark matter, involving nonsupersymmetric and non-WIMP solutions. We briefly discuss some examples of such candidates in their relationship with extension of particle symmetry and pattern of symmetry breaking. We specify in the example of axion-like particles nontrivial features of cosmological reflection of the structure and pattern of Peccei-Quinn-like symmetry breaking. The puzzles of direct and indiect dark matter searches can find solution in the approach of composite dark matter. The advantages and open problems of this approach are specified. We note that detailed analysis of cosmological consequences of any extension of particle model that provides candidates for dark matter inevitably leads to nonstandard features in the corresponding cosmological scenario. It makes possible to use methods of cosmoparticle physics to study physical nature of the dark matter in the combination of its physical, astrophysical and cosmological signatures.

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KHLOPOV, MAXIM. "FUNDAMENTAL PARTICLE STRUCTURE IN THE COSMOLOGICAL DARK MATTER." International Journal of Modern Physics A 28, no. 29 (November 20, 2013): 1330042. http://dx.doi.org/10.1142/s0217751x13300421.

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The nonbaryonic dark matter of the universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro-world and mechanisms of its symmetry breaking. Particle candidates for cosmological dark matter are lightest particles that bear new conserved quantum numbers. Dark matter particles may represent ideal gas of noninteracting particles. Self-interacting dark matter weakly or superweakly coupled to ordinary matter is also possible, reflecting nontrivial pattern of particle symmetry in the hidden sector of particle theory. In the early universe the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which macroscopic cosmological defects or primordial nonlinear structures can be originated. Primordial black holes (PBHs) can be not only a candidate for dark matter, but also represent a universal probe for superhigh energy physics in the early universe. Evaporating PBHs turn to be a source of even superweakly interacting particles, while clouds of massive PBHs can serve as nonlinear seeds for galaxy formation. The observed broken symmetry of the three known families may provide a simultaneous solution for the problems of the mass of neutrino and strong CP-violation in the unique framework of models of horizontal unification. Dark matter candidates can also appear in the new families of quarks and leptons and the existence of new stable charged leptons and quarks is possible, hidden in elusive "dark atoms." Such possibility, strongly restricted by the constraints on anomalous isotopes of light elements, is not excluded in scenarios that predict stable double charged particles. The excessive -2 charged particles are bound in these scenarios with primordial helium in O-helium "atoms," maintaining specific nuclear-interacting form of the dark matter, which may provide an interesting solution for the puzzles of the direct dark matter searches. In the context of cosmoparticle physics, studying fundamental relationship of micro- and macro-worlds, the problem of cosmological dark matter implies cross disciplinary theoretical, experimental and observational studies for its solution.

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CALDWELL, DAVID O. "THE SEARCH FOR DARK MATTER." Modern Physics Letters A 05, no. 20 (August 20, 1990): 1543–53. http://dx.doi.org/10.1142/s0217732390001761.

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The particle constituting probably more than 90% of the mass of the universe is unknown in the Standard Model of particle physics. Non-accelerator experiments, particularly those using Ge and Si detectors, and accelerator experiments, especially at SLC and LEP, have eliminated as dark matter wide classes of candidate particles. Examples are weak isodoublet neutrinos of mass ≳30 eV/c 2, sneutrinos, technibaryons, microcharged shadow matter, and probably Cosmions, which could both be dark matter and solve the solar neutrino problem.

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Robson, B. A. "Dark matter, dark energy and gravity." International Journal of Modern Physics E 24, no. 02 (February 2015): 1550012. http://dx.doi.org/10.1142/s0218301315500123.

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Within the framework of the Generation Model (GM) of particle physics, gravity is identified with the very weak, universal and attractive residual color interactions acting between the colorless particles of ordinary matter (electrons, neutrons and protons), which are composite structures. This gravitational interaction is mediated by massless vector bosons (hypergluons), which self-interact so that the interaction has two additional features not present in Newtonian gravitation: (i) asymptotic freedom and (ii) color confinement. These two additional properties of the gravitational interaction negate the need for the notions of both dark matter and dark energy.

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Runstedtler, Allan. "A model for the mass and distribution of particles in dark matter halos." Canadian Journal of Physics 96, no. 11 (November 2018): 1178–82. http://dx.doi.org/10.1139/cjp-2017-0804.

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This model is intended for dark-matter-dominated galaxies and galaxy clusters for which the centrifugal force caused by system rotation is negligible. Such systems, ostensibly dark matter halos, would tend to be spherical. Consider a uniform sphere of identical, massive particles in equilibrium (not contracting or expanding). In the quantum model, gravitation pulls the particles together and quantum uncertainty pushes them apart. In the corresponding classical model, gravitation pulls the particles together and thermal motion pushes them apart. This model provides an expression for particle mass as a function of the total mass and density of the system and its quantum state or temperature. Using the measured total mass and density of our dark-matter-dominated galaxy, and assuming the system is in the ground state, the particle mass is found to be 10.5 eV and the temperature 0.042 K. This represents the lowest possible system temperature and particle mass. If, on the other hand, the system is in equilibrium with the cosmic microwave background, the particle mass is found to be 693 eV. This range of inferred particle masses supports the hypothesis of “low-mass dark matter” with approximate mass 100 eV. However, the system temperature is not presently known so it is possible that the temperature is higher and, consequently, the particles are heavier. The average speed of the particles is found to be approximately 1/1000 the speed of light in our galaxy. Remarkably, this result does not depend on the system temperature and, therefore, does not depend on the particle mass. The extension of this model to variable density provides a straightforward solution to the “core-cusp problem” because the distribution of dark matter that minimizes the system energy has a flat central dark matter density profile.

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Bernabei, Rita. "Particle dark matter direct detection." International Journal of Modern Physics D 25, no. 07 (June 2016): 1630018. http://dx.doi.org/10.1142/s0218271816300184.

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Nearly a century of experimental observations and theoretical arguments have pointed out that a large fraction of the Universe is composed by dark matter particles. Many possibilities are open on the nature and interaction types of such relic particles. Moreover, the poor knowledge of many fundamental astrophysical, nuclear and particle physics aspects as well as of some experimental and theoretical parameters, the different used approaches and target materials, etc. make it challenging to understand the implication of some different experimental efforts. Some general arguments are addressed here. Future perspectives are mentioned.

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GRIB, A. A., and YU V. PAVLOV. "SUPERHEAVY PARTICLES IN FRIEDMANN COSMOLOGY AND THE DARK MATTER PROBLEM." International Journal of Modern Physics D 11, no. 03 (March 2002): 433–36. http://dx.doi.org/10.1142/s0218271802001706.

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The model of creation of observable particles and particles of the dark matter, considered to be superheavy particles, due to particle creation by the gravitational field of the Friedmann model of the early Universe is given. Estimates on the parameters of the model leading to observable values of the baryon number of the Universe and the dark matter density are made.

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Fornal, Bartosz, and Benjamín Grinstein. "Neutron’s dark secret." Modern Physics Letters A 35, no. 31 (August 21, 2020): 2030019. http://dx.doi.org/10.1142/s0217732320300190.

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The existing discrepancy between neutron lifetime measurements in bottle and beam experiments has been interpreted as a sign of the neutron decaying to dark particles. We summarize the current status of this proposal, including a discussion of particle physics models involving such a portal between the Standard Model and a baryonic dark sector. We also review further theoretical developments around this idea and elaborate on the prospects for verifying the neutron dark decay hypothesis in current and upcoming experiments.

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Foot, R. "Mirror dark matter: Cosmology, galaxy structure and direct detection." International Journal of Modern Physics A 29, no. 11n12 (April 25, 2014): 1430013. http://dx.doi.org/10.1142/s0217751x14300130.

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A simple way to accommodate dark matter is to postulate the existence of a hidden sector. That is, a set of new particles and forces interacting with the known particles predominantly via gravity. In general, this leads to a large set of unknown parameters, however, if the hidden sector is an exact copy of the standard model sector, then, an enhanced symmetry arises. This symmetry, which can be interpreted as space–time parity, connects each ordinary particle (e, ν, p, n, γ, …) with a mirror partner (e′, ν′, p′, n′, γ′, …). If this symmetry is completely unbroken, then the mirror particles are degenerate with their ordinary particle counterparts, and would interact amongst themselves with exactly the same dynamics that govern ordinary particle interactions. The only new interaction postulated is photon–mirror photon kinetic mixing, whose strength ϵ, is the sole new fundamental (Lagrangian) parameter relevant for astrophysics and cosmology. It turns out that such a theory, with suitably chosen initial conditions effective in the very early universe, can provide an adequate description of dark matter phenomena provided that ϵ~10-9. This review focusses on three main developments of this mirror dark matter theory during the last decade: early universe cosmology, galaxy structure and the application to direct detection experiments.

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Allen, Paul. "Dark particle." New Scientist 219, no. 2928 (August 2013): 30. http://dx.doi.org/10.1016/s0262-4079(13)61933-8.

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Rudakovskyi, A. V., and D. O. Savchenko. "New Model of Density Distribution for Fermionic Dark Matter Halos." Ukrainian Journal of Physics 63, no. 9 (September 24, 2018): 769. http://dx.doi.org/10.15407/ujpe63.9.769.

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We formulate a new model of density distribution for halos made of warm dark matter (WDM) particles. The model is described by a single microphysical parameter – the mass (or, equivalently, the maximal value of the initial phase-space density distribution) of dark matter particles. Given the WDM particle mass and the parameters of a dark matter density profile at the halo periphery, this model predicts the inner density profile. In the case of initial Fermi–Dirac distribution, we successfully reproduce cored dark matter profiles from N-body simulations. We calculate also the core radii of warm dark matter halos of dwarf spheroidal galaxies for particle masses mFD = 100, 200, 300, and 400 eV.

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Soln, Josip. "Connecting dark matter particles with the primary, obscure and normal particles through implicit causality." Applied Physics Research 9, no. 3 (May 10, 2017): 1. http://dx.doi.org/10.5539/apr.v9n3p1.

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The primary, obscure and normal particles with respective limiting velocities c1, c2 and c3,solutions from bicubic equation, offer comfortable venues to tackle the newly emergent dark matter particles. Particular emphasis is given to particles with velocities of O(10-3c) ( with c the velocity of light) and whose energies are from 1eV to over 100GeV for which the congruent parameter z = 3p3mv2/2E assumes values of 10-6 and 10-7. At z = 10-6 with mc2 = 100GeV one can have E = 260GeV or with E = 1eV one can have mc2 = 0:38eV; while at z = 10-7 with mc2 = 100GeV one can have E = 2:6TeV or with E = 1eV one can have mc2 = 0:038eV. The small values of the congruent parameter z allow the limiting velocities c1, c2 and c3 as well as the resulting energy expressions be written down perturbatevly in terms of the congruent parameter z.It is shown that for mc2 = 100GeV particle in the MilkyWay Dark Matter Velocity Profile (Laha, 2016), the derived limiting velocities of primary, obscure and normal particles as dark matter particles are: c1 = 1; 7c (z = 10-7), 1:34c; 2:15c (z = 10-6); c2 = +-i1; 7c (z = 10-7), +-i1:34c; +-i2:15c (z = 10-6), and c3 = v (z = 10-7; 10-6). Perturbatively, for a very small common primary and obscure particle velocity v compared to the absolute values of their limiting velocities, one shows that the obscure particle acquires (-mv2) intrinsic negative energy with respect to the primary particle,with m being their common mass.

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DUTTA, SOURISH, ROBERT J. SCHERRER, and STEPHEN D. H. HSU. "DARK ENERGY, WITH SIGNATURES." International Journal of Modern Physics D 19, no. 14 (December 2010): 2325–30. http://dx.doi.org/10.1142/s0218271810018372.

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We propose a class of simple dark energy models which predict a late-time dark radiation component and a distinctive time-dependent equation of state w(z) for redshift z < 3. The dark energy field can be coupled strongly enough to standard model particles to be detected in colliders, and the model requires only modest additional particle content and little or no fine-tuning other than a new energy scale of order milli-electron volts.

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Baudis, Laura. "The Search for Dark Matter." European Review 26, no. 1 (December 26, 2017): 70–81. http://dx.doi.org/10.1017/s1062798717000783.

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The dark matter problem is almost a century old. Since the 1930s evidence has been growing that our cosmos is dominated by a new form of non-baryonic matter that holds galaxies and clusters together and influences cosmic structures up to the largest observed scales. At the microscopic level, we still do not know the composition of this dark, or invisible, matter, which does not interact directly with light. The simplest assumption is that it is made of new particles that interact with gravity and, at most, weakly with known elementary particles. I will discuss searches for such new particles, both space- and Earth-bound, including those experiments placed in deep underground laboratories. While a dark matter particle has not yet been identified, even after decades of concerted efforts, new technological developments and experiments have reached sensitivities where a discovery might be imminent, albeit certainly not guaranteed.

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Allen, Roland E., and Aritra Saha. "Dark matter candidate with well-defined mass and couplings." Modern Physics Letters A 32, no. 25 (July 31, 2017): 1730022. http://dx.doi.org/10.1142/s0217732317300221.

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We propose a Higgs-related but spin-[Formula: see text] dark matter candidate with a mass that is comparable to that of the Higgs. This particle is a weakly interacting massive particle (WIMP) with an R-parity of [Formula: see text], but it can be distinguished from a neutralino by its unconventional couplings to W and Z bosons. Other neutral and charged spin-[Formula: see text] particles of a new kind are also predicted at higher energy.

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CALDWELL, DAVID O. "EXPERIMENTS ON WIMPS, SIMPS, AND HOT DARK MATTER." International Journal of Modern Physics D 03, supp01 (January 1994): 43–52. http://dx.doi.org/10.1142/s0218271894000940.

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The particle which constitutes more than 90% of the mass of the universe is not one of those in the Standard Model of particle physics. The search for this dark matter particle has now eliminated or severely restricted many candidates. While accelerator-produced results and indirect searches have helped, the most extensive exclusions have come from attempts at direct detection using semiconductor ionization detectors. The region excluded by direct detection extends over 12 orders of magnitude in particle mass and 20 orders of magnitude in cross section for Dirac particles. The need is now to get to cross sections less than one-tenth the weak cross section for Dirac masses >20 GeV and to use detectors having nuclei with spin for Majorana masses ≳10 GeV. Light neutrinos, while not detectable directly, can be eliminated as dominant dark matter if the 17-keV neutrino exists.

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Khlopov, Maxim Yu. "Probes for dark matter physics." International Journal of Modern Physics D 27, no. 06 (April 2018): 1841013. http://dx.doi.org/10.1142/s0218271818410134.

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The existence of cosmological dark matter is in the bedrock of the modern cosmology. The dark matter is assumed to be nonbaryonic and consists of new stable particles. Weakly Interacting Massive Particle (WIMP) miracle appeals to search for neutral stable weakly interacting particles in underground experiments by their nuclear recoil and at colliders by missing energy and momentum, which they carry out. However, the lack of WIMP effects in their direct underground searches and at colliders can appeal to other forms of dark matter candidates. These candidates may be weakly interacting slim particles, superweakly interacting particles, or composite dark matter, in which new particles are bound. Their existence should lead to cosmological effects that can find probes in the astrophysical data. However, if composite dark matter contains stable electrically charged leptons and quarks bound by ordinary Coulomb interaction in elusive dark atoms, these charged constituents of dark atoms can be the subject of direct experimental test at the colliders. The models, predicting stable particles with charge [Formula: see text] without stable particles with charges [Formula: see text] and [Formula: see text] can avoid severe constraints on anomalous isotopes of light elements and provide solution for the puzzles of dark matter searches. In such models, the excessive [Formula: see text] charged particles are bound with primordial helium in O-helium atoms, maintaining specific nuclear-interacting form of the dark matter. The successful development of composite dark matter scenarios appeals for experimental search for doubly charged constituents of dark atoms, making experimental search for exotic stable double charged particles experimentum crucis for dark atoms of composite dark matter.

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Belotsky, K., S. Rubin, and I. Svadkovsky. "Extended micro objects as dark matter particles." Modern Physics Letters A 32, no. 15 (April 25, 2017): 1740008. http://dx.doi.org/10.1142/s0217732317400089.

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Models of various forms of composite dark matter (DM) predicted by particle theory and the DM constituents formed by gravity that are not reduced to new elementary particle candidates are discussed. Main attention is paid to a gravitational origin of the DM. The influence of extended mass spectrum of primordial black holes on observational limits is considered. It is shown that non-uniformly deformed extra space can be considered as point-like masses which possess only gravitational interaction with each other and with the ordinary particles. The recently discussed six-dimensional stable wormholes could contribute to the DM. The contribution of dark atoms is also considered.

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KHLOPOV, M. Y., A. G. MAYOROV, and E. Y. SOLDATOV. "COMPOSITE DARK MATTER AND PUZZLES OF DARK MATTER SEARCHES." International Journal of Modern Physics D 19, no. 08n10 (August 2010): 1385–95. http://dx.doi.org/10.1142/s0218271810017962.

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Positive results of dark matter searches in DAMA/ NaI and DAMA/LIBRA experiments, being put together with the results of other groups, can imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2, bound with primordial helium in O -helium "atoms" ( OHe ), represent a specific warmer than cold nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground dark matter detection used in cryogenic experiments. However the radiative capture of OHe by Na and I nuclei can lead to annual variations of energy release in the energy interval of 2–5 keV in DAMA/ NaI and DAMA/LIBRA experiments.

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Shin, Seodong. "Non-minimal dark matter search in dark matter colliders." EPJ Web of Conferences 168 (2018): 06008. http://dx.doi.org/10.1051/epjconf/201816806008.

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In the scenarios of dark matter (DM) with a non-minimal dark sector, we revisit a new detection strategy of observing two or three simultaneous signals from inelastic scattering of a boosted DM [1]. The relativistically incoming DM can scatter off inelastically to a heavier unstable dark sector particle which decays back in to the DM associated with visible Standard Model particles inside large volume neutrino detectors. The existence of the secondary procedure renders us to separate it from conventional neutrino scattering background. The relativistically incoming DM can come from the universe by the annihilation of heavy DM component in an inelastic boosted DM scenario or produced by the beam bombardments in fixed target experiments.

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SIDHARTH, B. G. "A BRIEF NOTE ON MEV DARK MATTER." International Journal of Modern Physics E 14, no. 04 (June 2005): 631–33. http://dx.doi.org/10.1142/s0218301305003466.

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Recently, Boehm and co-workers have analyzed the newly detected 511 keV gamma rays from the galactic bulge based on data obtained from INTEGRAL. They conclude that these gamma rays are a consequence of low mass (~ MeV ) particle dark matter annihilations. Their conclusions are consistent with the halo profile favored by the observations, the annihilation cross-sections required for the radiation and also other astro particle physics constraints.1,2 It may be pointed out that exactly such a production of gamma rays from MeV particles was predicted by the author3 some years ago. This was based on a consideration of extremal black holes. We would like to point out that there is a spectrum of possible candidates.

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Yin, Wen. "Highly-boosted dark matter and cutoff for cosmic-ray neutrinos through neutrino portal." EPJ Web of Conferences 208 (2019): 04003. http://dx.doi.org/10.1051/epjconf/201920804003.

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We study the cutoff for the cosmic-ray neutrino, set by the scattering with cosmic background neutrinos into dark sector particles through a neutrino portal interaction. We find that a large interaction rate is still viable, when the dark sector particles are mainly coupled to the τ-neutrino, so that the neutrino mean free path can be reduced to be O(10) Mpc over a wide energy range. If stable enough, the dark sector particle, into which most of the cosmic-ray neutrino energy is transferred, can travel across the Universe and reach the earth. The dark sector particle can carry the energy as large as O(EeV) if it originates from a cosmogenic neutrino.

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BAUSHEV, ANTON. "DARK MATTER ANNIHILATION IN THE GRAVITATIONAL FIELD OF A BLACK HOLE." International Journal of Modern Physics D 18, no. 08 (August 2009): 1195–203. http://dx.doi.org/10.1142/s0218271809014509.

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In this paper we consider dark matter particle annihilation in the gravitational field of black holes. We obtain the exact distribution function of the infalling dark matter particles, and compute the resulting flux and spectra of gamma rays coming from the objects. It is shown that the dark matter density significantly increases near a black hole. Particle collision energy becomes very high, affecting relative cross-sections of various annihilation channels. We also discuss possible experimental consequences of these effects.

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Zhao, Yue, Michelle C. Fairhurst, Lisa M. Wingen, Véronique Perraud, Michael J. Ezell, and Barbara J. Finlayson-Pitts. "New insights into atmospherically relevant reaction systems using direct analysis in real-time mass spectrometry (DART-MS)." Atmospheric Measurement Techniques 10, no. 4 (April 11, 2017): 1373–86. http://dx.doi.org/10.5194/amt-10-1373-2017.

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Abstract. The application of direct analysis in real-time mass spectrometry (DART-MS), which is finding increasing use in atmospheric chemistry, to two different laboratory model systems for airborne particles is investigated: (1) submicron C3–C7 dicarboxylic acid (diacid) particles reacted with gas-phase trimethylamine (TMA) or butylamine (BA) and (2) secondary organic aerosol (SOA) particles from the ozonolysis of α-cedrene. The diacid particles exhibit a clear odd–even pattern in their chemical reactivity toward TMA and BA, with the odd-carbon diacid particles being substantially more reactive than even ones. The ratio of base to diacid in reacted particles, determined using known diacid–base mixtures, was compared to that measured by high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS), which vaporizes the whole particle. Results show that DART-MS probes ∼ 30 nm of the surface layer, consistent with other studies on different systems. For α-cedrene SOA particles, it is shown that varying the temperature of the particle stream as it enters the DART-MS ionization region can distinguish between specific components with the same molecular mass but different vapor pressures. These results demonstrate the utility of DART-MS for (1) examining reactivity of heterogeneous model systems for atmospheric particles and (2) probing components of SOA particles based on volatility.

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Lorenz, Jeanette Miriam. "Supersymmetry and the collider dark matter picture." Modern Physics Letters A 34, no. 30 (September 28, 2019): 1930005. http://dx.doi.org/10.1142/s0217732319300052.

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One of the key questions in particle physics and astrophysics is the nature of dark matter, the existence of which has been confirmed in many astrophysical and cosmological observations. Besides direct and indirect detection experiments, collider searches for dark matter offer the unique possibility to not only detect dark matter particles but in the case of discovery to also study their properties by making statements about the potential underlying theory. The search program for dark matter at the ATLAS and CMS experiments at the Large Hadron Collider is comprehensive, and includes both supersymmetric dark matter candidates and other alternatives. This review presents the latest status in these searches, with special focus on supersymmetric dark matter particles.

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Panotopoulos, Grigoris, and Ilídio Lopes. "Constraints on light dark matter particles using white dwarf stars." International Journal of Modern Physics D 29, no. 08 (June 2020): 2050058. http://dx.doi.org/10.1142/s0218271820500583.

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We report constraints on the nucleon-dark matter particle cross-section using the internal luminosity of observed white dwarf stars in the globular cluster Messier 4. Our results cover the parameter space corresponding to relatively light dark matter particles, in the sub GeV range, which is known to be very difficult to be probed by direct dark matter searches. The additional luminosity coming from self-annihilations of dark matter particles captured inside the stars must not exceed the observed luminosity. Imposing that condition, we obtain for the spin independent cross-section of light dark matter particles (below 5[Formula: see text]GeV) on baryons [Formula: see text] the upper bound: [Formula: see text].

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Mazziotta, M. N. "Indirect searches for dark matter with the Fermi LAT instrument." International Journal of Modern Physics A 29, no. 22 (August 29, 2014): 1430030. http://dx.doi.org/10.1142/s0217751x14300300.

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In this review the current status of several searches for particle dark matter with the Fermi Large Area Telescope instrument is presented. In particular, the current limits on the weakly interacting massive particles, obtained from the analyses of gamma-ray and cosmic ray electron/positron data, will be illustrated.

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Bottino, A. "A Dark Particle?" Science 283, no. 5406 (February 26, 1999): 1265f—1265. http://dx.doi.org/10.1126/science.283.5406.1265f.

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Huong, Do Thi. "Superheavy Dark Matter in the Supersymmetric Economical 3-3-1 Model." Communications in Physics 25, no. 3 (December 31, 2015): 211. http://dx.doi.org/10.15625/0868-3166/25/3/6523.

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We suggest the supersymmetric particles contained in the supersymmetric economical 3-3-1model were produced during the heating time. They have not been thermodynamic equilibrium when it frozeout. It leads to the lightest supersymmetric particle can be a good candidate for superheavy dark matter.With assumption the lightest supersymmetric particle is Bino, we show that the correct contribution of thesuperheavy dark matter species to the present critical density requires the Bino mass is order 1012 GeVand there is not exists a large mass hierarchy of the superpartner in the considered model.

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IBARRA, ALEJANDRO, DAVID TRAN, and CHRISTOPH WENIGER. "INDIRECT SEARCHES FOR DECAYING DARK MATTER." International Journal of Modern Physics A 28, no. 27 (October 30, 2013): 1330040. http://dx.doi.org/10.1142/s0217751x13300408.

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Numerous observations point towards the existence of an unknown elementary particle with no electromagnetic interactions, a large population of which was presumably produced in the early stages of the history of the Universe. This so-called dark matter has survived until the present day, accounting for the 26% of the present energy budget of the Universe. It remains an open question whether the particles comprising the dark matter are absolutely stable or whether they have a finite but very long lifetime, which is a possibility since there is no known general principle guaranteeing perfect stability. In this paper, we review the observational limits on the lifetime of dark matter particles with mass in the GeV–TeV range using observations of the cosmic fluxes of antimatter, gamma-rays and neutrinos. We also examine some theoretically motivated scenarios that provide decaying dark matter candidates.

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BARSHAY, SAUL, and GEORG KREYERHOFF. "LONG-RANGE INTERACTIONS BETWEEN DARK-MATTER PARTICLES IN A MODEL WITH A COSMOLOGICAL, SPONTANEOUSLY-BROKEN CHIRAL SYMMETRY." Modern Physics Letters A 20, no. 15 (May 20, 2005): 1155–60. http://dx.doi.org/10.1142/s0217732305017329.

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In a cosmological model with a chiral symmetry, there are two, dynamically-related spin-zero fields, a scalar ϕ and a pseudoscalar b. These fields have self-interactions. Spontaneous symmetry breaking results in a very massive scalar particle with mϕ≅5×1011 GeV , and a nearly massless, (Goldstone-like) pseudoscalar particle with 0<mb≲2.7×10-6 eV . One or both particles can be part of dark matter. There are coherent long-range interactions (at range ~ 1/mb≳10 cm ), from exchange of a b particle between a pair of b particles, a pair of ϕ particles, and between a ϕ and a b. We compare the strength of potentials for the different pairs to the corresponding gravitational potentials (within the same range ~ 1/mb), and show that the new force dominates between a b pair, that gravitation dominates between a ϕ pair, and that the potentials are comparable for a ϕ-b pair. The new interaction strength between a b pair is comparable to the gravitational interaction between a ϕ pair; its possibly greater coherent effect originates in the possibility that the number density of a very light b can be greater than that of a massive ϕ. We consider these results in the context of recent speculations concerning possible effects of special forces between dark-matter particles on certain galactic, and inter-galactic, properties.

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Casanellas, Jordi, and Ilídio Lopes. "The Sun and stars: Giving light to dark matter." Modern Physics Letters A 29, no. 37 (December 4, 2014): 1440001. http://dx.doi.org/10.1142/s021773231440001x.

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During the last century, with the development of modern physics in such diverse fields as thermodynamics, statistical physics, and nuclear and particle physics, the basic principles of the evolution of stars have been successfully well understood. Nowadays, a precise diagnostic of the stellar interiors is possible with the new fields of helioseismology and astroseismology. Even the measurement of solar neutrino fluxes, once a problem in particle physics, is now a powerful probe of the core of the Sun. These tools have allowed the use of stars to test new physics, in particular the properties of the hypothetical particles that constitute the dark matter (DM) of the Universe. Here we present recent results obtained using this approach.

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KHRIPLOVICH, I. B. "CAPTURE OF DARK MATTER BY THE SOLAR SYSTEM: SIMPLE ESTIMATES." International Journal of Modern Physics D 20, no. 01 (January 2011): 17–22. http://dx.doi.org/10.1142/s0218271811018640.

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We consider the capture of galactic dark matter by the solar system, due to the gravitational three-body interaction of the Sun, a planet, and a dark matter particle. Simple estimates are presented for the capture cross-section, as well as for the density and velocity distributions of captured dark matter particles close to the Earth.

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Kartika, Ika Amalia, and Dara Fegy Pratiwi. "KARAKTERISTIK PAPAN PARTIKEL DARI BAMBU DENGAN PEREKAT GETAH DAMAR." Jurnal Teknologi Industri Pertanian 28, no. 2 (August 2018): 127–39. http://dx.doi.org/10.24961/j.tek.ind.pert.2018.28.2.127.

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Hui, Lam. "Wave Dark Matter." Annual Review of Astronomy and Astrophysics 59, no. 1 (September 8, 2021): 247–89. http://dx.doi.org/10.1146/annurev-astro-120920-010024.

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We review the physics and phenomenology of wave dark matter: a bosonic dark matter candidate lighter than about 30 eV. Such particles have a de Broglie wavelength exceeding the average interparticle separation in a galaxy like the Milky Way and are, thus, well described as a set of classical waves. We outline the particle physics motivations for such particles, including the quantum chromodynamics axion as well as ultralight axion-like particles such as fuzzy dark matter. The wave nature of the dark matter implies a rich phenomenology: ▪ Wave interference gives rise to order unity density fluctuations on de Broglie scale in halos. One manifestation is vortices where the density vanishes and around which the velocity circulates. There is one vortex ring per de Broglie volume on average. ▪ For sufficiently low masses, soliton condensation occurs at centers of halos. The soliton oscillates and undergoes random walks, which is another manifestation of wave interference. The halo and subhalo abundance is expected to be suppressed at small masses, but the precise prediction from numerical wave simulations remains to be determined. ▪ For ultralight ∼10−22 eV dark matter, the wave interference substructures can be probed by tidal streams or gravitational lensing. The signal can be distinguished from that due to subhalos by the dependence on stream orbital radius or image separation. ▪ Axion detection experiments are sensitive to interference substructures for wave dark matter that is moderately light. The stochastic nature of the waves affects the interpretation of experimental constraints and motivates the measurement of correlation functions. Current constraints and open questions, covering detection experiments and cosmological, galactic, and black hole observations, are discussed.

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Dmytriiev, M. S., and V. V. Skalozub. "Dark matter polarization operator in the generalized Yukawa model." Journal of Physics and Electronics 28, no. 1 (September 10, 2020): 3–8. http://dx.doi.org/10.15421/332001.

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Nowadays, no dark matter candidates have been discovered. We consider the possible reason for that which is related to the approach of on-peak resonance searching for. As is believed usually, a new particle has small width and a narrow width approximation is applicable to identify such type resonant peak in the invariant mass spectrum of collision products. In the present paper, in the framework of the generalized Yukawa model, we find out the propertiesof the searched particle when its width is larger than a maximal one expected during experiments and so this state could be missed as a noise. Usually, the new particle width is considered as an arbitrary parameter. Here, we obtain the width of the dark matter particle from an imaginary part of polarization operators. Then the width is analyzed as explicit function of the couplings and masses in the underlying model of the dark matter. The corresponding constraints on the model parameters are obtained. Role of the one-loop mixing of visible and dark matter fields is investigated and constraint on the mixing angle value is derived. These estimations are quite general and, in particular, relevant to interactions between the particles of the Standard model and dark matter.

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Yamamoto, Yasuhiro. "Atomki anomaly and the Secluded Dark Sector." EPJ Web of Conferences 168 (2018): 06007. http://dx.doi.org/10.1051/epjconf/201816806007.

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The Atomiki anomaly can be interpreted as a new light vector boson. If such a new particle exists, it could be a mediator between the Standard Model sector and the dark sector including the dark matter. We discussed some simple effective models with these particles. In the models, the secluded dark matter models are good candidates to satisfy the thermal relic abundance. In particular, we found that the dark matter self-interaction can be large enough to solve the small scale structure puzzles if the dark matter is a fermion.

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Supriyatin, Titin, Dwi Aprillia Setia Asih, and Avini Nurazhimah Arfa. "Analisis pembelajaran daring pada materi dinamika partikel ditinjau dari komunikasi matematis." Navigation Physics : Journal of Physics Education 3, no. 1 (June 30, 2021): 45–52. http://dx.doi.org/10.30998/npjpe.v3i1.684.

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This study aims to analyze the achievement of each indicator that measures students' mathematical understanding abilities in basic physics courses on particle dynamics material. This research is a qualitative descriptive study that seeks to describe the analysis of students' mathematical understanding abilities. The research subjects were 6 class 3 semester students of biology education consisting of 198 students. The data collection method used includes tests of students' mathematical understanding abilities in basic physics courses which include particle dynamics material. Based on the results of the study, it was concluded that the level of ability of biology education students in basic physics courses was as follows: (1) Students already had the ability to solve problems was good enough on particle dynamics material from questions 1 to 5 had an average percentage of 56.2% , (2) Students have reasoning abilities (reasoning on particle dynamics material from questions 1 to 5 have an average percentage of 14.4%, (3) Students have communication skills (communication) on particle dynamics material from questions 1 to 5 have The average percentage is 12.2%, (4) students have the ability to make connections to the dynamic material of particles from questions 1 to 5, have an average percentage of 12.4%; (5) students have representation ability ) on the particle dynamics material from questions 1 to 5 has an average percentage of 4.8%.

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Di Girolamo, Paolo, Andrea Scoccione, Marco Cacciani, Donato Summa, Benedetto De Rosa, and Jan H. Schween. "Clear-air lidar dark band." Atmospheric Chemistry and Physics 18, no. 7 (April 10, 2018): 4885–96. http://dx.doi.org/10.5194/acp-18-4885-2018.

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Abstract. This paper illustrates measurements carried out by the Raman lidar BASIL in the frame of the HD(CP)2 Observational Prototype Experiment (HOPE), revealing the presence of a clear-air dark band phenomenon (i.e. a minimum in lidar backscatter echoes) in the upper portion of the convective boundary layer. The phenomenon is clearly distinguishable in the lidar backscatter echoes at 532 and 1064 nm, as well as in the particle depolarisation data. This phenomenon is attributed to the presence of lignite aerosol particles advected from the surrounding open pit mines in the vicinity of the measuring site. The paper provides evidence of the phenomenon and illustrates possible interpretations for its occurrence.

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Grib, A. A., and Yu V. Pavlov. "Black holes and high energy physics." International Journal of Modern Physics A 31, no. 02n03 (January 20, 2016): 1641016. http://dx.doi.org/10.1142/s0217751x16410165.

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Three mechanisms of getting high energies in particle collisions in the ergosphere of the rotating black holes are considered. The consequences of these mechanisms for observation of ultra high energy cosmic rays particles on the Earth as result of conversion of superheavy dark matter particles into ordinary particles are discussed.

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Drukier, A. K., K. Freese, and D. N. Spergel. "Detecting Cold Dark Matter Candidates." Symposium - International Astronomical Union 117 (1987): 490. http://dx.doi.org/10.1017/s0074180900150703.

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We consider the use of superheated superconducting colloids as detectors of weakly interacting galactic halo candidate particles (e.g. photinos, massive neutrinos, and scalar neutrinos). These low temperature detectors are sensitive to the deposition of a few hundreds of eV's. The recoil of a dark matter particle off of a superheated superconducting grain in the detector causes the grain to make a transition to the normal state. Their low energy threshold makes this class of detectors ideal for detecting massive weakly interacting halo particles.We discuss realistic models for the detector and for the galactic halo. We show that the expected count rate (≈103 count/day for scalar and massive neutrinos) exceeds the expected background by several orders of magnitude. For photinos, we expect ≈1 count/day, more than 100 times the predicted background rate. We find that if the detector temperature is maintained at 50 mK and the system noise is reduced below 5 × 10−4 flux quanta, particles with mass as low as 2 GeV can be detected. We show that the earth's motion around the Sun can produce a significant annual modulation in the signal.

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Trevisani, Nicolò. "Collider Searches for Dark Matter (ATLAS + CMS)." Universe 4, no. 11 (November 20, 2018): 131. http://dx.doi.org/10.3390/universe4110131.

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Several searches for dark matter have been performed by the CMS and ATLAS collaborations, using proton-proton collisions with a center-of-mass energy of 13 TeV produced by the Large Hadron Collider. Different signatures may highlight the presence of dark matter: the imbalance in the transverse momentum in an event due to the presence of undetectable dark matter particles, produced together with one Standard Model particle, a bump in the di-jet or di-lepton invariant mass distributions, or an excess of events in the di-jet angular distribution, produced by a dark matter mediator. No significant discrepancies with respect to the Standard Model predictions have been found in data, so that limits on the dark matter couplings to ordinary matter, or limits on the dark matter particles and mediators masses have been set. The results are also re-interpreted as limits on the dark matter interaction cross-section with baryonic matter, so that a comparison with direct detection experiments is allowed.

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Haller Jr., John L. "Dark Particles Answer Dark Energy." Journal of Modern Physics 04, no. 07 (2013): 85–95. http://dx.doi.org/10.4236/jmp.2013.47a1010.

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Shibli, Murad. "The fundamental particle and energy quanta of dark matter and dark energy: Boltzmann particles and utilization its energy." Renewable Energy and Power Quality Journal 1, no. 07 (April 2009): 854–57. http://dx.doi.org/10.24084/repqj07.528.

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Scopel, S. "Particle dark matter candidates." Journal of Physics: Conference Series 120, no. 4 (July 1, 2008): 042003. http://dx.doi.org/10.1088/1742-6596/120/4/042003.

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Journal articles on the topic 'Particle darō'

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