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Dark matter

Savvas M Koushiappas, Abraham Loeb
We study the effects of black hole dark matter on the dynamical evolution of stars in dwarf galaxies. We find that mass segregation leads to a depletion of stars in the center of dwarf galaxies and the appearance of a ring in the projected stellar surface density profile. Using Segue 1 as an example we show that current observations of the projected surface stellar density rule out at the 99.9% confidence level the possibility that more than 6% of the dark matter is composed of black holes with a mass of few tens of solar masses...
July 28, 2017: Physical Review Letters
J P Lees, V Poireau, V Tisserand, E Grauges, A Palano, G Eigen, D N Brown, M Derdzinski, A Giuffrida, Yu G Kolomensky, M Fritsch, H Koch, T Schroeder, C Hearty, T S Mattison, J A McKenna, R Y So, V E Blinov, A R Buzykaev, V P Druzhinin, V B Golubev, E A Kravchenko, A P Onuchin, S I Serednyakov, Yu I Skovpen, E P Solodov, K Yu Todyshev, A J Lankford, J W Gary, O Long, A M Eisner, W S Lockman, W Panduro Vazquez, D S Chao, C H Cheng, B Echenard, K T Flood, D G Hitlin, J Kim, T S Miyashita, P Ongmongkolkul, F C Porter, M Röhrken, Z Huard, B T Meadows, B G Pushpawela, M D Sokoloff, L Sun, J G Smith, S R Wagner, D Bernard, M Verderi, D Bettoni, C Bozzi, R Calabrese, G Cibinetto, E Fioravanti, I Garzia, E Luppi, V Santoro, A Calcaterra, R de Sangro, G Finocchiaro, S Martellotti, P Patteri, I M Peruzzi, M Piccolo, M Rotondo, A Zallo, S Passaggio, C Patrignani, H M Lacker, B Bhuyan, U Mallik, C Chen, J Cochran, S Prell, H Ahmed, A V Gritsan, N Arnaud, M Davier, F Le Diberder, A M Lutz, G Wormser, D J Lange, D M Wright, J P Coleman, E Gabathuler, D E Hutchcroft, D J Payne, C Touramanis, A J Bevan, F Di Lodovico, R Sacco, G Cowan, Sw Banerjee, D N Brown, C L Davis, A G Denig, W Gradl, K Griessinger, A Hafner, K R Schubert, R J Barlow, G D Lafferty, R Cenci, A Jawahery, D A Roberts, R Cowan, S H Robertson, B Dey, N Neri, F Palombo, R Cheaib, L Cremaldi, R Godang, D J Summers, P Taras, G De Nardo, C Sciacca, G Raven, C P Jessop, J M LoSecco, K Honscheid, R Kass, A Gaz, M Margoni, M Posocco, G Simi, F Simonetto, R Stroili, S Akar, E Ben-Haim, M Bomben, G R Bonneaud, G Calderini, J Chauveau, G Marchiori, J Ocariz, M Biasini, E Manoni, A Rossi, G Batignani, S Bettarini, M Carpinelli, G Casarosa, M Chrzaszcz, F Forti, M A Giorgi, A Lusiani, B Oberhof, E Paoloni, M Rama, G Rizzo, J J Walsh, A J S Smith, F Anulli, R Faccini, F Ferrarotto, F Ferroni, A Pilloni, G Piredda, C Bünger, S Dittrich, O Grünberg, M Heß, T Leddig, C Voß, R Waldi, T Adye, F F Wilson, S Emery, G Vasseur, D Aston, C Cartaro, M R Convery, J Dorfan, W Dunwoodie, M Ebert, R C Field, B G Fulsom, M T Graham, C Hast, W R Innes, P Kim, D W G S Leith, S Luitz, D B MacFarlane, D R Muller, H Neal, B N Ratcliff, A Roodman, M K Sullivan, J Va'vra, W J Wisniewski, M V Purohit, J R Wilson, A Randle-Conde, S J Sekula, M Bellis, P R Burchat, E M T Puccio, M S Alam, J A Ernst, R Gorodeisky, N Guttman, D R Peimer, A Soffer, S M Spanier, J L Ritchie, R F Schwitters, J M Izen, X C Lou, F Bianchi, F De Mori, A Filippi, D Gamba, L Lanceri, L Vitale, F Martinez-Vidal, A Oyanguren, J Albert, A Beaulieu, F U Bernlochner, G J King, R Kowalewski, T Lueck, I M Nugent, J M Roney, R J Sobie, N Tasneem, T J Gershon, P F Harrison, T E Latham, R Prepost, S L Wu
We search for single-photon events in 53  fb^{-1} of e^{+}e^{-} collision data collected with the BABAR detector at the PEP-II B-Factory. We look for events with a single high-energy photon and a large missing momentum and energy, consistent with production of a spin-1 particle A^{'} through the process e^{+}e^{-}→γA^{'}; A^{'}→invisible. Such particles, referred to as "dark photons," are motivated by theories applying a U(1) gauge symmetry to dark matter. We find no evidence for such processes and set 90% confidence level upper limits on the coupling strength of A^{'} to e^{+}e^{-} in the mass range m_{A^{'}}≤8  GeV...
September 29, 2017: Physical Review Letters
Javier Tiffenberg, Miguel Sofo-Haro, Alex Drlica-Wagner, Rouven Essig, Yann Guardincerri, Steve Holland, Tomer Volansky, Tien-Tien Yu
We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068  e^{-} rms/pixel. This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons...
September 29, 2017: Physical Review Letters
Ely D Kovetz
Primordial black holes (PBHs) have long been suggested as a candidate for making up some or all of the dark matter in the Universe. Most of the theoretically possible mass range for PBH dark matter has been ruled out with various null observations of expected signatures of their interaction with standard astrophysical objects. However, current constraints are significantly less robust in the 20  M_{⊙}≲M_{PBH}≲100  M_{⊙} mass window, which has received much attention recently, following the detection of merging black holes with estimated masses of ∼30  M_{⊙} by LIGO and the suggestion that these could be black holes formed in the early Universe...
September 29, 2017: Physical Review Letters
Masha Baryakhtar, Joseph Bramante, Shirley Weishi Li, Tim Linden, Nirmal Raj
We identify a largely model-independent signature of dark matter (DM) interactions with nucleons and electrons. DM in the local galactic halo, gravitationally accelerated to over half the speed of light, scatters against and deposits kinetic energy into neutron stars, heating them to infrared blackbody temperatures. The resulting radiation could potentially be detected by the James Webb Space Telescope, the Thirty Meter Telescope, or the European Extremely Large Telescope. This mechanism also produces optical emission from neutron stars in the galactic bulge, and x-ray emission near the galactic center because dark matter is denser in these regions...
September 29, 2017: Physical Review Letters
Asher Berlin
We propose a new thermal freeze-out mechanism for ultraheavy dark matter. Dark matter coannihilates with a lighter unstable species that is nearby in mass, leading to an annihilation rate that is exponentially enhanced relative to standard weakly interactive massive particles. This scenario destabilizes any potential dark matter candidate. In order to remain consistent with astrophysical observations, our proposal necessitates very long-lived states, motivating striking phenomenology associated with the late decays of ultraheavy dark matter, potentially as massive as the scale of grand unified theories, M_{GUT}∼10^{16}  GeV...
September 22, 2017: Physical Review Letters
Ekrem Aydiner
In this study, we consider nonlinear interactions between components such as dark energy, dark matter, matter and radiation in the framework of the Friedman-Robertson-Walker space-time and propose a simple interaction model based on the time evolution of the densities of these components. By using this model we show that these interactions can be given by Lotka-Volterra type equations. We numerically solve these coupling equations and show that interaction dynamics between dark energy-dark matter-matter or dark energy-dark matter-matter-radiation has a strange attractor for 0 > w de  >-1, w dm  ≥ 0, w m  ≥ 0 and w r  ≥ 0 values...
January 15, 2018: Scientific Reports
Kyu Jung Bae, Tae Hyun Jung, Myeonghun Park
We propose a spectral decomposition to systematically extract information of dark matter at hadron colliders. The differential cross section of events with missing transverse energy (E_{T}) can be expressed by a linear combination of basis functions. In the case of s-channel mediator models for dark matter particle production, basis functions are identified with the differential cross sections of subprocesses of virtual mediator and visible particle production while the coefficients of basis functions correspond to dark matter invariant mass distribution in the manner of the Källén-Lehmann spectral decomposition...
December 29, 2017: Physical Review Letters
David B Litt, Matthew Jones, Mario Hentschel, Ying Wang, Sui Yang, Hyun Dong Ha, Xiang Zhang, A Paul Alivisatos
Metamaterials are architectures that interact with light in novel ways by virtue of symmetry manipulation, and have opened a window into studying unprecedented light-matter interactions. However, they are commonly fabricated via lithographic methods, are usually static structures, and are limited in how they can react to external stimuli. Here we show that by combining lithographic techniques with DNA-based self-assembly methods, we can construct responsive plasmonic metamaterials that exhibit the plasmonic analog of an effect known as electromagnetically induced transparency (EIT), which can dramatically change their spectra upon motion of their constituent parts...
January 5, 2018: Nano Letters
Jeremy Sakstein, Bhuvnesh Jain
The LIGO and VIRGO Collaborations have recently announced the detection of gravitational waves from a neutron star-neutron star merger (GW170817) and the simultaneous measurement of an optical counterpart (the γ-ray burst GRB 170817A). The close arrival time of the gravitational and electromagnetic waves limits the difference in speed of photons and gravitons to be less than about 1 part in 10^{15}. This has three important implications for cosmological scalar-tensor gravity theories that are often touted as dark energy candidates and alternatives to the Λ cold dark matter model...
December 22, 2017: Physical Review Letters
Rasmus S L Hansen, Stefan Vogl
Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum...
December 22, 2017: Physical Review Letters
Paolo Creminelli, Filippo Vernizzi
The observation of GW170817 and its electromagnetic counterpart implies that gravitational waves travel at the speed of light, with deviations smaller than a few×10^{-15}. We discuss the consequences of this experimental result for models of dark energy and modified gravity characterized by a single scalar degree of freedom. To avoid tuning, the speed of gravitational waves must be unaffected not only for our particular cosmological solution but also for nearby solutions obtained by slightly changing the matter abundance...
December 22, 2017: Physical Review Letters
Nicola Willis, Webster Mavhu, Carol Wogrin, Abigail Mutsinze, Ashraf Kagee
BACKGROUND: Studies have found that adolescents living with HIV are at risk of depression, which in turn affects adherence to medication. This study explored the experience and manifestation of depression in adolescents living with HIV in Zimbabwe in order to inform intervention development. METHODS: We conducted a body mapping exercise with 21 HIV positive 15-19 years olds who had been diagnosed with major depressive disorder. Participants created a painted map of their body to assist them in expressing their somatic and emotional experiences in qualitative interviews...
2018: PloS One
Ivan De Martino, Tom Broadhurst, S-H Henry Tye, Tzihong Chiueh, Hsi-Yu Schive, Ruth Lazkoz
Light axionic dark matter, motivated by string theory, is increasingly favored for the "no weakly interacting massive particle era". Galaxy formation is suppressed below a Jeans scale of ≃10^{8}  M_{⊙} by setting the axion mass to m_{B}∼10^{-22}  eV, and the large dark cores of dwarf galaxies are explained as solitons on the de Broglie scale. This is persuasive, but detection of the inherent scalar field oscillation at the Compton frequency ω_{B}=(2.5  months)^{-1}(m_{B}/10^{-22}  eV) would be definitive...
December 1, 2017: Physical Review Letters
D D Vorontsov, V E Dyakonova
We have recently demonstrated that preceding motor activity can facilitate decision-making not only in humans and mammals but also in molluscs.5 In the behavioral paradigm used, snails Lymnaea stagnalis were removed from their natural environment (water) and placed in a dry, asymmetrically lit arena from which they had to decide which way to go in order to reach an aquatic environment. One possible explanation of the observed effects of preceding motor activity was that it could affect the snail's memory of light conditions that corresponded to its previous aquatic habitat...
2017: Communicative & Integrative Biology
Aurélie Diman, Anabelle Decottignies
Long non-coding RNAs, produced from distinct regions of the chromosomes, are emerging as new key players in several important biological processes. The long non-coding RNAs add a new layer of complexity to cellular regulatory pathways, from transcription to cellular trafficking or chromatin remodeling. More than 25 years ago, the discovery of a transcriptional activity at telomeres of protozoa ended the long-lasting belief that telomeres were transcriptionally silent. Since then, progressively accumulating evidences established that production of TElomeric Repeat-containing RNA (TERRA) was a general feature of eukaryotic cells...
December 14, 2017: FEBS Journal
E Aprile, J Aalbers, F Agostini, M Alfonsi, F D Amaro, M Anthony, F Arneodo, P Barrow, L Baudis, B Bauermeister, M L Benabderrahmane, T Berger, P A Breur, A Brown, A Brown, E Brown, S Bruenner, G Bruno, R Budnik, L Bütikofer, J Calvén, J M R Cardoso, M Cervantes, D Cichon, D Coderre, A P Colijn, J Conrad, J P Cussonneau, M P Decowski, P de Perio, P Di Gangi, A Di Giovanni, S Diglio, G Eurin, J Fei, A D Ferella, A Fieguth, W Fulgione, A Gallo Rosso, M Galloway, F Gao, M Garbini, R Gardner, C Geis, L W Goetzke, L Grandi, Z Greene, C Grignon, C Hasterok, E Hogenbirk, J Howlett, R Itay, B Kaminsky, S Kazama, G Kessler, A Kish, H Landsman, R F Lang, D Lellouch, L Levinson, Q Lin, S Lindemann, M Lindner, F Lombardi, J A M Lopes, A Manfredini, I Mariş, T Marrodán Undagoitia, J Masbou, F V Massoli, D Masson, D Mayani, M Messina, K Micheneau, A Molinario, K Morå, M Murra, J Naganoma, K Ni, U Oberlack, P Pakarha, B Pelssers, R Persiani, F Piastra, J Pienaar, V Pizzella, M-C Piro, G Plante, N Priel, L Rauch, S Reichard, C Reuter, B Riedel, A Rizzo, S Rosendahl, N Rupp, R Saldanha, J M F Dos Santos, G Sartorelli, M Scheibelhut, S Schindler, J Schreiner, M Schumann, L Scotto Lavina, M Selvi, P Shagin, E Shockley, M Silva, H Simgen, M V Sivers, A Stein, S Thapa, D Thers, A Tiseni, G Trinchero, C Tunnell, M Vargas, N Upole, H Wang, Z Wang, Y Wei, C Weinheimer, J Wulf, J Ye, Y Zhang, T Zhu
We report the first dark matter search results from XENON1T, a ∼2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042±12)-kg fiducial mass and in the [5,40]  keV_{nr} energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1...
November 3, 2017: Physical Review Letters
Xiangyi Cui, Abdusalam Abdukerim, Wei Chen, Xun Chen, Yunhua Chen, Binbin Dong, Deqing Fang, Changbo Fu, Karl Giboni, Franco Giuliani, Linhui Gu, Yikun Gu, Xuyuan Guo, Zhifan Guo, Ke Han, Changda He, Di Huang, Shengming He, Xingtao Huang, Zhou Huang, Xiangdong Ji, Yonglin Ju, Shaoli Li, Yao Li, Heng Lin, Huaxuan Liu, Jianglai Liu, Yugang Ma, Yajun Mao, Kaixiang Ni, Jinhua Ning, Xiangxiang Ren, Fang Shi, Andi Tan, Cheng Wang, Hongwei Wang, Meng Wang, Qiuhong Wang, Siguang Wang, Xiuli Wang, Xuming Wang, Qinyu Wu, Shiyong Wu, Mengjiao Xiao, Pengwei Xie, Binbin Yan, Yong Yang, Jianfeng Yue, Dan Zhang, Hongguang Zhang, Tao Zhang, Tianqi Zhang, Li Zhao, Jifang Zhou, Ning Zhou, Xiaopeng Zhou
We report a new search for weakly interacting massive particles (WIMPs) using the combined low background data sets acquired in 2016 and 2017 from the PandaX-II experiment in China. The latest data set contains a new exposure of 77.1 live days, with the background reduced to a level of 0.8×10^{-3}  evt/kg/day, improved by a factor of 2.5 in comparison to the previous run in 2016. No excess events are found above the expected background. With a total exposure of 5.4×10^{4}  kg day, the most stringent upper limit on the spin-independent WIMP-nucleon cross section is set for a WIMP with mass larger than 100  GeV/c^{2}, with the lowest 90% C...
November 3, 2017: Physical Review Letters
Changbo Fu, Xiaopeng Zhou, Xun Chen, Yunhua Chen, Xiangyi Cui, Deqing Fang, Karl Giboni, Franco Giuliani, Ke Han, Xingtao Huang, Xiangdong Ji, Yonglin Ju, Siao Lei, Shaoli Li, Huaxuan Liu, Jianglai Liu, Yugang Ma, Yajun Mao, Xiangxiang Ren, Andi Tan, Hongwei Wang, Jimin Wang, Meng Wang, Qiuhong Wang, Siguang Wang, Xuming Wang, Zhou Wang, Shiyong Wu, Mengjiao Xiao, Pengwei Xie, Binbin Yan, Yong Yang, Jianfeng Yue, Hongguang Zhang, Tao Zhang, Li Zhao, Ning Zhou
We report new searches for solar axions and galactic axionlike dark matter particles, using the first low-background data from the PandaX-II experiment at China Jinping Underground Laboratory, corresponding to a total exposure of about 2.7×10^{4}  kg day. No solar axion or galactic axionlike dark matter particle candidate has been identified. The upper limit on the axion-electron coupling (g_{Ae}) from the solar flux is found to be about 4.35×10^{-12} in the mass range from 10^{-5} to 1  keV/c^{2} with 90% confidence level, similar to the recent LUX result...
November 3, 2017: Physical Review Letters
Humphrey J Maris, George M Seidel, Derek Stein
We describe a method for dark matter detection based on the evaporation of helium atoms from a cold surface and their subsequent detection using field ionization. When a dark matter particle scatters off a nucleus of the target material, elementary excitations (phonons or rotons) are produced. Excitations which have an energy greater than the binding energy of helium to the surface can result in the evaporation of helium atoms. We propose to detect these atoms by ionizing them in a strong electric field. Because the binding energy of helium to surfaces can be below 1 meV, this detection scheme opens up new possibilities for the detection of dark matter particles in a mass range down to 1  MeV/c^{2}...
November 3, 2017: Physical Review Letters
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