Search results for "galaxy"

showing 10 items of 1505 documents

Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches

2018

Motivated by the recent galactic center gamma-ray excess identified in the Fermi-LAT data, we perform a detailed study of QCD fragmentation uncertainties in the modeling of the energy spectra of gamma-rays from Dark-Matter (DM) annihilation. When Dark-Matter particles annihilate to coloured final states, either directly or via decays such as $W^{(*)}\to q\bar{q}'$, photons are produced from a complex sequence of shower, hadronisation and hadron decays. In phenomenological studies, their energy spectra are typically computed using Monte Carlo event generators. These results have however intrinsic uncertainties due to the specific model used and the choice of model parameters, which are diffi…

dark matter simulationsParticle physicsCosmology and Nongalactic Astrophysics (astro-ph.CO)PhotonAstrophysics::High Energy Astrophysical Phenomenamodel [hadronization]SLDgamma ray theoryDark matterMonte Carlo methodHadronFOS: Physical sciencesmass [dark matter]01 natural sciencesHigh Energy Physics - Phenomenology (hep-ph)fragmentationquantum chromodynamics0103 physical sciencesconservation lawddc:530High Energy PhysicsMonte Carloenergy spectrum [gamma ray]Quantum chromodynamicsPhysicsdark matter theoryAnnihilation010308 nuclear & particles physicsphotonGamma rayCERN LEP StorAstronomy and AstrophysicsshowersGalaxyHigh Energy Physics - PhenomenologyannihilationExperimental High Energy PhysicsHigh Energy Physics::Experimentgalaxydecay [hadron]GLAST [interpretation of experiments]Astrophysics - Cosmology and Nongalactic Astrophysics
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Energy transfer in diiodoBodipy-grafted upconversion nanohybrids.

2015

Steady-state and time-resolved emission studies on nanohybrids consisting of NaYF4:Yb,Er and a diiodo-substituted Bodipy (UCNP-IBDP) show that the Yb(3+) metastable state, formed after absorption of a near-infrared (NIR) photon, can decay via two competitive energy transfer processes: sensitization of IBDP after absorption of a second NIR photon and population of Er(3+) excited states.

education.field_of_studyPhotonMaterials scienceEnergy transferPopulationPhysics::OpticsNanotechnologyAstrophysics::Cosmology and Extragalactic Astrophysics02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesPhoton upconversion0104 chemical scienceschemistry.chemical_compoundchemistryExcited stateMetastabilityGeneral Materials ScienceBODIPY0210 nano-technologyAbsorption (electromagnetic radiation)educationAstrophysics::Galaxy AstrophysicsNanoscale
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Search for magnetically-induced signatures in the arrival directions of ultra-high-energy cosmic rays measured at the Pierre Auger Observatory

2020

We search for signals of magnetically-induced effects in the arrival directions of ultra-high-energy cosmic rays detected at the Pierre Auger Observatory. We apply two different methods. One is a search for sets of events that show a correlation between their arrival direction and the inverse of their energy, which would be expected if they come from the same point-like source, they have the same electric charge and their deflection is relatively small and coherent. We refer to these sets of events as "multiplets". The second method, called "thrust", is a principal axis analysis aimed to detect the elongated patterns in a region of interest. We study the sensitivity of both methods using a …

electric [charge]AstronomydeflectionThrustmagnetic fieldAstrophysics01 natural sciencesmass spectrumhelium: nucleusbenchmarksurface [detector]Cosmic ray experimentsUltra-high-energy cosmic ray010303 astronomy & astrophysicsPhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)astro-ph.HEAstrophysics::Instrumentation and Methods for AstrophysicsCosmic ray experiments; Ultra high energy cosmic raysAugerobservatoryacceleration [cosmic radiation]Astrophysics - High Energy Astrophysical PhenomenasignaturePrincipal axis theoremActive galactic nucleusCherenkov counter: waterAstrophysics::High Energy Astrophysical PhenomenaUHE [cosmic radiation]energy spectrumFOS: Physical sciencesnucleus [helium]Cosmic rayElectric chargeCosmic ray experimentGLASTdetector: fluorescence0103 physical sciencesddc:530thrustcosmic radiation: UHEHigh Energy Physicscosmic radiation: accelerationAGNAstrophysiquePierre Auger Observatoryfluorescence [detector]010308 nuclear & particles physicsdetector: surfacecharge: electricwater [Cherenkov counter]Astronomy and AstrophysicsUltra high energy cosmic raysAstronomiesensitivityGalaxycoherencefluxgamma raymultipletcorrelationExperimental High Energy Physicsgalaxy[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]RAIOS CÓSMICOS
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"Table 110" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…

2019

$|{\cos{\theta}^{\star}}|$ normalized differential cross-section at parton level. The parton level phase-space is limited to the region $p_T^{t,1} > 500~$GeV, $p_T^{t,2} > 350~$GeV.

endocrine systemPP -->$t\bar{t}$ ---> L_JET L_JETurogenital systemHigh Energy Physics::Phenomenology$|{\cos{\theta}^{\star}}|$Astrophysics::Solar and Stellar AstrophysicsHigh Energy Physics::Experimentparton levelPP -->$t\bar{t}$ ---> all-hadronicNuclear Experiment${cos{\theta}^{\star}}$13000Astrophysics::Galaxy Astrophysics
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"Table 170" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…

2018

${cos{\theta}^{\star}}$ correlation matrix for relative differential cross-section in parton level

endocrine systemPP -->$t\bar{t}$ ---> L_JET L_JETurogenital systemHigh Energy Physics::PhenomenologyAstrophysics::Solar and Stellar AstrophysicsHigh Energy Physics::Experimentparton levelNuclear Experiment${cos{\theta}^{\star}}$13000Astrophysics::Galaxy Astrophysics
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"Table 168" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…

2018

${cos{\theta}^{\star}}$ correlation matrix for absolute differential cross-section in parton level

endocrine systemPP -->$t\bar{t}$ ---> L_JET L_JETurogenital systemHigh Energy Physics::PhenomenologyAstrophysics::Solar and Stellar AstrophysicsHigh Energy Physics::Experimentparton levelNuclear Experiment${cos{\theta}^{\star}}$13000Astrophysics::Galaxy Astrophysics
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"Table 169" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…

2018

${cos{\theta}^{\star}}$ covariance matrix for relative differential cross-section in parton level

endocrine systemPP -->$t\bar{t}$ ---> L_JET L_JETurogenital systemHigh Energy Physics::PhenomenologyAstrophysics::Solar and Stellar AstrophysicsHigh Energy Physics::Experimentparton levelNuclear Experiment${cos{\theta}^{\star}}$13000Astrophysics::Galaxy Astrophysics
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"Table 167" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…

2018

${cos{\theta}^{\star}}$ covariance matrix for absolute differential cross-section in parton level

endocrine systemPP -->$t\bar{t}$ ---> L_JET L_JETurogenital systemHigh Energy Physics::PhenomenologyAstrophysics::Solar and Stellar AstrophysicsHigh Energy Physics::Experimentparton levelNuclear Experiment${cos{\theta}^{\star}}$13000Astrophysics::Galaxy Astrophysics
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"Table 95" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…

2018

${cos{\theta}^{\star}}$ absolute differential cross-section in parton level

endocrine systemPP -->$t\bar{t}$ ---> L_JET L_JETurogenital systemHigh Energy Physics::PhenomenologyAstrophysics::Solar and Stellar AstrophysicsHigh Energy Physics::Experimentparton levelNuclear Experiment${cos{\theta}^{\star}}$13000Astrophysics::Galaxy Astrophysics
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"Table 168" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…

2019

$|{\cos{\theta}^{\star}}|$ correlation matrix for the absolute differential cross-section at parton level

endocrine systemurogenital systemHigh Energy Physics::PhenomenologyAstrophysics::Solar and Stellar Astrophysics$|{\cos{\theta}^{\star}}|$High Energy Physics::Experimentparton levelPP -->$t\bar{t}$ ---> all-hadronicNuclear Experiment13000Astrophysics::Galaxy Astrophysics
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