3,674 research outputs found
Superheavy WIMP dark matter from incomplete thermalization
No full textAlthough it is usually thought that a class of weakly interacting massive particle (WIMP) dark matters (DMs), which have the vector coupling with the Z boson, is denied by null results of the direct DM searches, such WIMP DMs are still viable if they are superheavy with the mass of m(DM) greater than or similar to 10(9) GeV. In the future, the superheavy WIMP DMs can be searched up to m(DM) similar or equal to 10(12) GeV, which corresponds to the so-called neutrino floor limit. We show that the observed abundance of Omega(DM)h(2) similar or equal to 0.1 for a superheavy WIMP DM can be reproduced by a suitable reheating temperature of T-R similar or equal to m(DM)/29 after inflation, if the direct inflaton decay into DM is negligible or kinematically forbidden. (C) 2021 The Author(s). Published by Elsevier B.V
Técnicas e filosofias de produtividade com o raciocínio da administração emocional /
No full textDissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico
Inelastic extra U(1) charged scalar dark matter
No full textThe null results in dark matter direct detection experiments imply the present scalar dark matter (DM) annihilation cross section to bottom quark pairs through the Eliggs boson exchange is smaller than about 10(-31) cm(3)/s for a wide DM mass range, which is much smaller than the required annihilation cross section for thermal relic DM. We propose models of a thermal relic DM with the present annihilation cross section being very suppressed. This property can be realized in an extra U(1) gauge interacting complex scalar DM, where the thermal DM abundance is determined by coannihilation through the gauge interaction while the present annihilation is governed by Higgs bosons exchange processes. An interaction between DM and the extra U(1) breaking Higgs field generates a small mass splitting between DM and its coannihilating partner so that coannihilation becomes possible and also the Z'-mediated scattering off with a nucleon in direct DM search becomes inelastic. We consider scalar dark matter in U(1)(B-L), U(1)((B,L)3) and U(1)L-mu-L-tau, extended models and identify viable parameter regions. We also discuss various implications to future DM detection experiments, the DM interpretation of the gamma-ray excess in the globular cluster 47 Tucanae, the muon anomalous magnetic moment, the Hubble tension and others
Entanglement and quantity in quantum space - About quantum measurement (II)
No full textAs a continuation and extension of "quantity in phase space" "quantity in quantum space" is introduced. With that, the disappearing of quantum interference discussed in a previous paper [S. Durr, et al., Nature 395 (1998) 33] is explained in the same spirit as our recent papers [Ren De-Ming, Commun. Theor. Phys. (Beijing, China) 41 (2004) 685, 833].Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)1ARTICLE133-364
Sneutrino DM in the NMSSM with inverse seesaw mechanism
No full textIn supersymmetric theories like the Next-to-Minimal Supersymmetric Standard Model (NMSSM), the lightest neutralino with bino or singlino as its dominant component is customarily taken as dark matter (DM) candidate. Since light Higgsinos favored by naturalness can strength the couplings of the DM and thus enhance the DM-nucleon scattering rate, the tension between naturalness and DM direct detection results becomes more and more acute with the improved experimental sensitivity. In this work, we extend the NMSSM by inverse seesaw mechanism to generate neutrino mass, and show that in certain parameter space the lightest sneutrino may act as a viable DM candidate, i.e. it can annihilate by multi-channels to get correct relic density and meanwhile satisfy all experimental constraints. The most striking feature of the extension is that the DM-nucleon scattering rate can be naturally below its current experimental bounds regardless of the higgsino mass, and hence it alleviates the tension between naturalness and DM experiments. Other interesting features include that the Higgs phenomenology becomes much richer than that of the original NMSSM due to the relaxed constraints from DM physics and also due to the presence of extra neutrinos, and that the signatures of sparticles at colliders are quite different from those with neutralino as DM candidate.National Natural Science Foundation of China (NNSFC) [11575053]SCI(E)ARTICLE1
Classical mechanics and quantum mechanics
No full textThe Newton equation of motion is derived from quantum mechanics.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)2ARTICLE5685-6884
Policy-driven Data Sharing over Attribute-Based Encryption supporting Dual Membership
No full textAttribute-Based Encryption (ABE) plays an important role in current secure data sharing through fine-grained customizable policies. However, the existing ABE schemes only support simple predicates, = and ≠, but cannot express a more general membership predicates, ∈ and ∉, in policies. The low expressivity of ABE will enlarge the ciphertext storage and reduce the communication efficiency. To overcome this problem, we propose an ABE supporting Dual Membership (DM-ABE). The core problem for implementing this scheme is how to use cryptographic methods to decide the membership between the verified element and the given set. In order to solve this problem, we design a cryptographic algorithm, called Secure Decision of Membership (SDM), based on aggregation functions. In this algorithm, any set can be aggregated into one cryptographic element, and the verified element and the given set can be converted into another cryptographic element in decision process. The membership between them can be decided by the above two cryptographic elements. Furthermore, we construct the DM-ABE by using SDM. Because of the good expressivity of our DM-ABE, we further propose a novel cryptographic data sharing framework by integrating DM-ABE and attribute-based access control to provide fine-grained access control and security protection for private data. In the security proof of DM-ABE, we prove that the DM-ABE satisfies the semantic security against chosen-plaintext attacks under the DBDHE assumption in the standard model through a unified way, considering both two encryption methods for ∈ and ∉ at the same time. Finally, we analyze our scheme in terms of time and space complexity, and compare it with some existing schemes. The results show that our DM-ABE has a better expressive ability on the boolean logic of general membership predicates, ∈ and ∉.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Cyber Securit
Constraining the Inner Galactic DM Density Profile with H.E.S.S.
No full text© 2024 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).In this short review, corresponding to a talk given at the conference “Cosmology 2023 in Miramare”, we combine an analysis of five regions observed by H.E.S.S. in the Galactic Center, intending to constrain the Dark Matter (DM) density profile in a WIMP annihilation scenario. For the analysis, we include the state-of-the-art Galactic diffuse emission Gamma-optimized model computed with DRAGON and a wide range of DM density profiles from cored to cuspy profiles, including different kinds of DM spikes. Our results are able to constrain generalized NFW profiles with an inner slope ≳1.3 . When considering DM spikes, the adiabatic spike is completely ruled out. However, smoother spikes given by the interactions with the bulge stars are compatible if ≲0.8 , with an internal slope of sp-stars=1.5.This work has been supported by the grants PID2021-125331NB-I00, PID2022-139841NB-I00, and CEX2020-001007-S, funded by MCIN/AEI/10.13039/501100011033, by “ERDF A way of making Europe”, and the MULTIDARK Project RED2022-134411-T. The author’s contribution to this work has been supported by the FPI Severo Ochoa PRE2021-099137 grant.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2020-001007-S).Peer reviewe
Diabetes mellitus (DM) related lower extremity amputations (LEA) rate and risk factors.
No full textAuthor: Ieva Vasiliūtė Title: Diabetes mellitus (DM) related lower extremity amputations (LEA) rate and risk factors. Aim: To investigate LEA rate and risk factors in patients with DM. Objectives: To evaluate DM related LEA rate. To determine DM related LEAs levels and patients demographic factors relation. To determine DM related LEAs levels and type of DM relation. To determine DM related LEAs levels and DM duration, body mass index (BMI), glycated hemoglobin (HbA1c) meanings relation. To evaluate expected mathematically based risk factors. Methods: Retrospective medical records study of 153 patients with DM, who underwent LEAs at the Hospital of Lithuanian University of Health Sciences Kaunas clinics was performed during the 2012 01 01 – 2014 12 31 period. Statistical analysis was performed using the standard SPSS 20.0 program. Results: 33,33% of legs amputations occured among people with DM and 66,67% of them were male (p<0,001). Major LEAs were performed mostly in patients with type 2 DM (86,96%) than those with type 1 DM (p<0,001). Male patients LEAs were performed in patients suffering for shorter duration of DM than in women (19,18 m. (±95% PI 16,71-21,65) vs. 23,36 m. (±95% PI 20,07-26,65), p=0,053). Patients with type 2 DM underwent LEAs had DM for shorter durations (16,19 m. (±95% PI 14,32-18,06)) than those with type 1 DM patients (31,43 m. (±95% PI 28,40-34,45)) ( p<0,001). Major LEAs remove patients had BMI (32,86±5,55 kg/m2) than minor LEAs remove patients (29,13±5,91 kg/m2) (p=0,027). No significant relation was found with amputation level and HbA1c average (p=0,246). DM related eye damage increases the risk of minor LEAs 3,10 times (p=0,001). Obesity/overweight the risk of major LEAs increases 5,65 times (p=0,036) and 2,56 times with obliterate atherosclerosis (p=0,006). Patients with type 2 DM have a 3,2 times (p=0,002) higher risk of undergoing major LEA. Conclusions: A third of patients who had undergone LEAs had DM. Amputations were carried out more frequently in men. DKA arose more often in patients with type 2 DM. LEAs were performed a shorter duration male DM patients. Type 2 DM patients suffered LEAs nearly 2 times shorter duration. Major LEAs experienced patients had a higher BMI. The average of HbA1c is not significantly related with amputation levels. DM related eye damage increases the minor LEAs risk by 3,10 times. Obesity/being overweight increases the risk of major LEAs 5,65 times, obliterate atherosclerosis - 2,56 times. Patients with type 2 DM have a 3,2 times higher risk of major LEA
Dirac dark matter, dark radiation, and the type-II seesaw mechanism in alternative standard model
No full textWe propose an extra model with an alternative charge assignment for
right-handed right-handed neutrinos. The type-II seesaw mechanism by a triplet
Higgs field is promising for neutrino mass generation because of the
alternative charge assignment. The small vacuum expectation value (VEV) of an
additional Higgs doublet naturally leads to a very small VEV of the triplet
Higgs field, and as a result, the smallness of neutrino mass can be understood.
With the minimal Higgs field for with the charge , right-handed
neutrinos are candidates for Dirac dark matter (DM) and dark radiation (DR). We
have derived and imposed the LHC bound, the DR constraint and the bound from DM
direct searches in the wide range of parameter space. Among various
choices, the DM direct search bound is found to be weakest for where
the constraints from thermal DM and non-negligible DR can be compatible. Such a
number of the effective neutrino species would be interesting from the
viewpoint of the so-called Hubble tension.Comment: 21 pages, 6 figures, the title slightly changed, discussion and
references added, the journal published versio
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