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Simulação da razão de carga de múons atmosféricos na escala TeV / Simulation of the charge ratio of the muons atmospheric energy scale TeVCosta, Kelen Cristiane Noleto da 30 September 2011 (has links)
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Previous issue date: 2011-09-30 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Several analysis can be performed using atmospheric muons produced in
chain reactions caused by a cosmic ray particle. We can study the muon flux for different
parameterizations of the atmosphere, the moon and sun shadowing effect, the
muon charge ratio, etc. In this work, we are interested in the atmospheric muon charge
ratio (rμ = Nμ+/Nμ−). This ratio has been observed by several experiments, for different
energy ranges. The MINOS experiment has determined the muon charge ratio (rμ) in
the GeV energy scale using the Near Detector and in the TeV energy scale using the
Far Detector. This experiment has observed an increase of the muon charge ratio from
1.27 to 1.37 when the energy of the primary particle changed from ∼ 100 GeV to ∼ 1
TeV. This fact can be explained by the properties of the pions ( ) and the kaons (K). For
higher energies, around 10 TeV, the decay of charming hadrons becomes important as
a source of atmospheric leptons.
Investigating the parameterization given by the Gaisser equation in order to
study the intensity of positive and negative muons separately, it is possible to obtain
the equation of the pion-kaon ( K) model. Using this model it was made an adjust
with the of MINOS Near and Far Detector data, finding the f and fK parameters.
These parameters are the fractions that contribute to the production of positive muons
coming from de e K, respectively. The experimental values obtained were: f = 0.55
and fK = 0.70.
In this work we simulated extensive air showers using the CORSIKA code.
Different models that describe the hadronic interactions for high energy particles were
used. Our goal was to verify if the models could reproduce the increase of muon
charge ratio. This increase is associated with physics involving pion and kaon decays.
We found the following parameters: f = 0.547 ± 0.003 and fK = 0.64 ± 0.02 for the QGSJET 01C model, f = 0.604 ± 0.003 and fK = 0.73 ± 0.02 for the SIBYLL model,
f = 0.572 ± 0.003 and fK = 0.70 ± 0.02 for the VENUS model, f = 0.545 ± 0.004 and
fK = 0.62 ± 0.03 for the QGSJETII model and f = 0.570 ± 0.003 and fK = 0.65 ± 0.02
for the DPMJET model. The increase of the muon charge ratio found in the MINOS
data was 7.8%. In our simulation we found an increase of 3.2%, 8.3%, 5.7%, %4.0 and
2.5% for each one of the models, respectively.
With these results, it was possible to observe that simulation models also
show a significant increase of ratio, when we moved from scale GeV scale for TeV. And
of course, this increase is characterized by properties of pions and kaons noting that
physics is considered by the codes of models. / Várias análises podem ser feitas a partir de múons atmosféricos produzidos
na reação em cadeia provocada por uma partícula de raio cósmico, como o estudo do
fluxo de múons para diferentes parametrizações da atmosfera, da sombra da lua e do
sol, da razão da carga entre múons atmosféricos. Neste trabalho estamos interessados
na razão da carga entre múons atmosféricos (rμ = Nμ+/Nμ−). Essa razão foi
determinada por diversos experimentos, para diferentes intervalos de energias. Especificamente,
o experimento MINOS determinou a razão (rμ) na escala GeV com o
Near Detector e na escala TeV com o Far Detector. Esse experimento observou um
aumento da razão de 1,27 para 1,37 com o aumento da energia de ∼100 GeV para ∼ 1
TeV. O aumento dessa razão pode ser entendido a partir das propriedades dos píons
( ) e káons (K). Para energias maiores, cerca de 10 TeV, o decaimento de hádrons
charmosos torna-se importante como fonte de léptons atmosféricos.
Investigando a parametrização dada pela equação de Gaisser para estudar
separadamente a intensidade dos múons positivos e negativos, é possível chegar na
equação do modelo píon-káon ( K). Utilizando este modelo, foi feito um ajuste com
os dados do MINOS Near e Far Detector, encontrando os parâmetros f e fK. Esses
parâmetros são as frações que contribuem para a produção de múons positivos vindos
de e K, respectivamente. Os valores experimentais encontrados foram: f = 0,55 e
fK = 0,70.
Neste trabalho simulamos chuveiros atmosféricos com o código CORSIKA.
Diferentes modelos de interações hadrônicas de altas energias foram utilizados. O
objetivo foi verificar se os modelos conseguiriam reproduzir o aumento da razão da
carga de múons entre GeV e TeV. Esse aumento está associado à física envolvida no
decaimento dos píons e káons. Encontramos os seguintes parâmetros: f = 0,550 ± 0,006 e fK = 0,61±0,03 para o modelo QGSJET 01C, f = 0,611±0,004 e fK = 0,67±0,02
para o modelo SIBYLL, f = 0,571 ± 0,005 e fK = 0,70 ± 0,03 para o modelo VENUS,
f = 0,547±0,006 e fK = 0,61±0,04 para o modelo QGSJETII e para o modelo DPMJET,
f = 0,574±0,004 e fK = 0,63±0,02. O aumento da razão para os dados do experimento
MINOS foi de 7,8%; para a nossa simulação o aumento foi de 3,2%; 8,3%; 5,7%; 2,4%
e 2,9%; respectivamente.
Com esses resultados, foi possível observar que os modelos de simulação
também evidenciam um aumento significativo da razão, quando passamos da escala
GeV para escala TeV. Esse aumento é caracterizado pelas propriedades dos píons e
káons, constatando que essa física é considerada pelos códigos dos modelos.
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Étude de la production de saveurs lourdes et de la multiplicité de particules chargées dans le cadre du formalisme du Color Glass Condensate pour les collisions p+p et p+Pb dans l'expérience ALICE au LHCMalek, M. 20 July 2009 (has links) (PDF)
La matière nucléaire classique se caractérise par des densités d'énergie de l'ordre de " = 0,17 GeV/fm3. Pour des conditions critiques en densité d'énergie 5 -10 " ou en température de 150 - 200 MeV, la chromodynamique quantique (QCD) sur réseau prédit une transition de phase entre la matière nucléaire classique et un nouvel état de la matière : le Plasma de Quarks et de Gluons (PQG) dans lequel les quarks et les gluons seraient déconfinés. Les collisions d'ions lourds ultra-relativistes permettent de créer des conditions thermodynamiques, i.e. un milieu dense et chaud, très favorable à la formation du PQG. Le LHC offre la possibilité de faire des collisions proton-proton et des collisions d'ions lourds à des énergies de plusieurs TeV par nucléon. Les énergies disponibles permettront de tester expérimentalement différents formalismes théoriques de la QCD développés afin de décrire les collisions d'ions lourds dans la limite des hautes énergies. La compréhension des conditions initiales de la collision est obligatoire afin de comprendre l'évolution du système vers un état de PQG. L'un des formalismes les plus discutés depuis ces dernières années qui décrit ces conditions initiales est le Color Glass Condensate (CGC). Il prédit la saturation de la densité partonique au sein des noyaux dans le domaine des petites valeurs de Bjorken-x correspondant à de grandes pseudorapidités. ALICE est l'une des expériences du LHC consacrée à l'étude des collisions d'ions lourds ultra-relativistes et en particulier à l'analyse des propriétés du PQG. Une des signatures possibles de la création du PQG est la suppression des taux de production des quarkonia (J/ , ) par écrantage de couleur dans un milieu déconfiné. Le spectromètre à muons de l'expérience ALICE permettra de mesurer les taux de production des quarkonia via leur canal de désintégration muonique dans un domaine de pseudorapidité -4 < < -2,5. Les effets de saturation, plus importants à grande pseudorapidité, font du spectromètre à muons d'ALICE un détecteur tout particulièrement approprié pour cette étude. La première partie de ce travail porte sur l'installation et la préparation du spectromètre à muons d'ALICE en vue des premières prises des données. Les tests de l'électronique frontale et des chambres du système de trajectographie du spectromètre à muons conduisent à la conclusion que la station 1 du spectromètre à muons est prête à enregistrer les premières données physiques. La seconde partie présente l'étude du CGC par deux voies expérimentales : la production des saveurs lourdes (charme et beauté) et la multiplicité des particules chargées. Nous montrons que l'état final de la collision est affecté par l'existence du CGC dans l'état initial. Ce travail mène à la conclusion que le LHC permettra une étude de cette nouvelle physique jamais explorée auparavant.
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Étude du calorimètre électromagnétique de l'expérience CMS et recherche de bosons de Higgs neutres dans le canal de production associéeRavat, Olivier El Mamouni, Houmani January 2004 (has links) (PDF)
Reproduction de : Thèse de doctorat : Physique des particules : Lyon 1 : 2004. / Titre provenant de l'écran titre. 103 réf. bibliogr.
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Measurement of cosmic-ray muon induced neutrons in the Aberdeen Tunnelunderground laboratory in Hong KongNgai, Ho-yin., 倪浩然. January 2012 (has links)
The Daya Bay reactor neutrino experiment aims to determine sin2 2θ13
with a sensitivity of 0.01 or better at 90% confidence level. One of the major
backgrounds to neutrino measurements is the muon-induced neutrons. An ex-
periment had been set up inside the Aberdeen Tunnel laboratory, Hong Kong,
to study spallation neutrons induced by cosmic-ray muons in an underground
environment similar to the Daya Bay experiment.
The Aberdeen Tunnel laboratory is 22 m above sea level at 22:23?N and
114:6?E. The amount of overburden is approximately 235 m of rocks, which
is equivalent to 611 m.w.e. Rock compositions in the Aberdeen Tunnel area
is similar to that in Daya Bay. MUSIC simulation results showed that in the
laboratory the mean energy of muons 〈Eμ〉= 122 GeV and the integrated muon
intensity I = 9:64 X10??6 cm??2 s??1.
A Bonner Spheres Neutron Spectrometer (BSS) was developed to measure
the ambient neutron energy spectrum. The BSS consists of a thermal neutron
detector and a set of eight polyethylene spherical shells. The overall detection efficiency of the BSS was (96:7 +3:3
??13:1)% with a detector background rate of
(1:96_0:03)_10??3 s??1. The total neutron fluence rate measured at the Surface
Assembly Building (SAB) of the Daya Bay experiment was (5:20 +0:81
??0:44) _ 10??3
cm??2 s??1, which agreed with the neutron fluence rate measured in the air/ground
interface in Taiwan. The unfolded SAB neutron energy spectrum showed a clear
thermal-neutron peak around 20 meV and a cascade peak around 100 MeV. Detectable number of neutrons could be seen at 1 GeV. The neutron fluence rate
measured at the Aberdeen Tunnel (ABT) laboratory was significantly higher
then some other underground laboratories. The unfolded ABT neutron energy
spectrum showed a pronounced evaporation peak around 1 MeV, and a sup-
pression in the cascade peak.
Detections of muon-induced neutrons inside the Aberdeen Tunnel laboratory
is achieved by a Muon Tracker and a Neutron Detector. The Muon Tracker
consists of three main layers of crossed plastic scintillator hodoscopes capable
of determining the incoming direction of muons. The average efficiency for most
of the hodoscopes was above 95%. The Neutron Detector consists of about 760
L of gadolinium-doped liquid scintillator and sixteen photomultiplier tubes. The
liquid scintillator target is shield by about 1900 L of mineral oil from external
radiations. The overall average detection efficiency of muon-induced neutrons
was about 16%.
The measurement of muon-induced neutrons in the Aberdeen Tunnel lab-
oratory started from June 2011, with a total live time of about 30 days. The
average rate of the accepted muon events was 0.013 Hz. The muon-induced
neutron yield was determined to be Nn = (8:5 _ 0:4(syst.) _ 1:8(stat.)) _
10??5 neutron/(μg cm??2). This value agreed with the parametrization of
FLUKA-1999 simulation results if the muon energy dependence of muon-induced
neutron yields was considered. / published_or_final_version / Physics / Doctoral / Doctor of Philosophy
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Analysis of cosmic-ray-muon induced spallation neutrons in Aberdeen Tunnel experiment in Hong KongCui, Kexi, 崔科晰 January 2014 (has links)
The muon-induced radioactive isotopes, especially neutrons, are dangerous background component for rare-event detection in underground experiments, like neutrino-less double-beta decay and dark matter search. Understanding these cosmogenic backgrounds is crucial for these experiments. An underground experiment aiming at measuring the cosmic-ray muons' flux and their neutron production yield in liquid scintillator through spallation process is being carried out in the Aberdeen Tunnel laboratory located in Hong Kong with a total vertical overburden of 235 m of rocks (611 m.w.e.).
The Aberdeen Tunnel detection system is constituted of a Muon Tracker (MT) for muon tagging and a Neutron Detector (ND) for neutron detection. The MT consists of 60 plastic scintillator hodoscopes to determine the incoming muon direction and the ND is a two-zone detector containing 760 L of gadolinium-doped liquid scintillator as target volume and 1900 L of mineral oil as shields. The experiment has been taking data stably since 2012. To obtain reliable results, the detector performance and the stability of the experiment have been studied in this work. Muon-induced fast neutrons can be captured in Gd-LS with characteristic energies released and the capture time follows a characteristic exponential distribution. By using the capture time and energy information, we can select the neutron candidates and thus calculate the neutron production yield. The energy of a neutron capture event is reconstructed from the calibrated photo-multiplier tube signals, while the directions of cosmic-ray muons can be reconstructed from the MT.
The mean energy of the incoming muons that pass the selection criteria was estimated by a simulation code MUSIC that transported atmospheric muon spectrum through the mountains to the laboratory, and is found to be 92 GeV. The neutron production yield is calculated to be Yn = (3:28 ±0:12(sta:) ±0:24(sys:)) X 〖10〗^(-4) (n/μ〖gcm〗^(-2)) for both the showering muon and single muon events. This result is about two times higher than the expectation value from previous simulations and experiments. The neutron production yield of the single muons is calculated to be Yn = (1:04 ± 0:08(sta:) ± 0:07(sys:)) X 〖10〗^(-4) (n/μ〖gcm〗^(-2)). This reveals a enhancement of the neutron production from the muons accompanied by showers. / published_or_final_version / Physics / Master / Master of Philosophy
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Measurements on electron and muon components in small cosmic ray air showers陳紹鉅, Chan, Siu-kui, Darnay. January 1983 (has links)
published_or_final_version / Physics / Doctoral / Doctor of Philosophy
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Measurement of the product branching ratio [Formula] / Measurement of the product branching ratio f(bottom quark going to Lambda(b)) dot BR(Lambda(b) going to Lambda lepton( - ) anti-neutrino anything)Steuerer, Johannes Martin 14 May 2015 (has links)
Graduate
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The perturbative and non-perturbative QCD effects in the azimuthal distribution of hadron jets observed in muon deep inelastic scattering /Jin, Zhong, January 1997 (has links)
Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (p. [107]-111).
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Estudo de eficiência para múons do sistema de veto do experimento Neutrinos-ANGRA / A study for the muon efficiency of the veto system for the Neutrinos-ANGRA experimentSantos, Lucas Mendes, 1988- 26 August 2018 (has links)
Orientador: Ernesto Kemp / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-26T09:14:52Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014 / Resumo: O neutrino, atualmente, é uma das partículas de maior interesse para estudo. Seu comportamento oscilatório requer que os neutrinos tenham massa, em escalas desafiadoras para uma simples acomodação com o mecanismo de Higgs possibilitado pelas simetrias eletrofracas. Do ponto de vista de detecção, sua baixa secção de choque introduz grande dificuldade no projeto de detectores eficientes. O Projeto Neutrinos-ANGRA visa, através da detecção de neutrinos, monitorar o reator ANGRA-II situado no Complexo Nuclear de Angra dos Reis - Rio de Janeiro. Para tanto, propõe utilizar um detector de radiação Cherenkov em água, instalado na superfície. Contudo, a esse nível, as taxas de ruído provenientes principalmente de raios cósmicos, são ordens de grandeza maior que a frequência efetiva da passagem do neutrino pelo material ativo. Em uma proposta para reduzir essas taxas, o alvo central será circundado com uma blindagem com elementos ativos e passivos. Nesta dissertação foi dado um enfoque especial à blindagem ativa quanto a incidência de múons, principal componente da radiação cósmica, sobre o detector. Neste estudo foram simulados 3×10^(6)múons não correlacionados temporalmente, porém obedecendo parâmetros bem estabelecidos das distribuição angular e de energia, e foi observado o comportamento da eficiência da blindagem à diferentes critérios de corte. Por fim, foram analisadas as taxas de ruídos aleatórios (não-correlacionados), fixando com uma das partículas participantes o múon. Foi possível determinar um critério de trigger para ao sistema de veto ativo (sinal > 50 fotoelétrons). Nestas condições, o sistema mostrou-se 99,73% eficiente, reduzindo a taxa de sinal:ruído, considerando a presença de pelo menos um múon, de 0,6:1 para 22:1 / Abstract: The neutrino is currently one of the particles of greatest interest to study. its oscillatory behavior requires that neutrinos have mass, in challenging scales for a simple accommodation with the Higgs mechanism enabled by the electroweak symmetry. From the viewpoint of detection, the low cross-section introduces a great distress in designing efficient detectors. The Neutrino-ANGRA Project aims, through the detection of neutrinos, monitor ANGRA-II reactor located in Angra dos Reis Nuclear Complex - Rio de Janeiro. We propose to use a detector of Cherenkov radiation in water, installed on the surface. However, at this level, rates of noise mainly from cosmic rays, are orders of magnitude greater than the effective frequency of the passage of the neutrino active material. In a bid to reduce these rates, the central target will be surrounded with a shield with active and passive elements. In this work a special focus to the active shielding as the incidence of muons, the main component of cosmic radiation on the detector, was given. This study simulated muon 3×10^(6) time-uncorrelated but obeying the well-established angular distribution and energy parameters, and the behavior of the shielding efficiency of different criteria cutting was observed. Finally, the rates of (uncorrelated) random noise, with a setting of the muon particle participants were analyzed. It was possible to derive a criterion to trigger the active veto (signal > 50 photoelectrons) system. Accordingly, the system proved to be 99.73% efficient, reducing the rate signal:noise, whereas the presence of at least one muon from 0.6: 1 to 22:1 / Mestrado / Física / Mestre em Física
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A Deep-Learning-Based Muon Neutrino CCQE Selection for Searches Beyond the Standard Model with MicroBooNECianci, Davio January 2021 (has links)
The anomalous Low Energy Excess (LEE) of electron neutrinos and antineutrinos in MiniBooNE has inspired both theories and entire experiments to probe the heart of its mystery. One such experiment is MicroBooNE. This dissertation presents an important facet of its LEE investigation: how a powerful systematic can be levied on this signal through parallel study of a highly correlated channel in muon neutrinos. This constraint serves to strengthen MicroBooNE's ability to confirm or validate the cause of the LEE and will lay the groundwork for future oscillation experiments in Liquid Argon Time Projection Chamber (LArTPC) detector experiments like SBN and DUNE. In addition, this muon channel can be used to test oscillations directly, demonstrated through the world's first muon neutrino disappearance search with LArTPC data.
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