Search results for "Astrophysics"
showing 10 items of 8341 documents
Women Scientists Who Made Nuclear Astrophysics
2019
Female role models reduce the impact on women of stereotype threat, i.e. of being at risk of conforming to a negative stereotype about one’s social, gender, or racial group (Fine in Delusion of Gender. W.W. Norton & Co. NY, p. 36, 2010 [1]; Steele and Aronson in J Pers Soc Psychol 69:797–811, 1995 [2]). This can lead women scientists to underperform or to leave their scientific career because of negative stereotypes such as, not being as talented or as interested in science as men. Sadly, history rarely provides role models for women scientists; instead, it often renders these women invisible (CafeBabel Homepage [3]). In response to this situation, we present a selection of twelve outst…
Observation of Astrophysical Neutrinos in Four Years of IceCube Data
2015
The spectrum of cosmic rays includes the most energetic particles ever observed. The mechanism of their acceleration and their sources are, however, still mostly unknown. Observing astrophysical neutrinos can help solve this problem. This update extends the data-taking period by one more year to four years from 2010 to 2014 for a total livetime of 1347 days.
IceCube-22 Solar WIMP Data: Searching for Muon Neutrinos from Dark Matter Annihilations in the Sun
2009
Relic dark matter in the galactic halo may become gravitationally trapped in the Sun and accumulate in its center, where it can annihilate each other, producing standard model particles, which may decay creating neutrinos. A search was performed using data from the IceCube detector in its 22 string configuration. The experimental dataset consists of 104.26 days livetime, corresponding to a set of runs recorded during the period when the Sun was below the horizon at the South Pole, between March 21st and September 23rd.
Astrophysical muon neutrino flux in the northern sky with 2 years of IceCube data
2015
Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere data set consisting primarily of νe and ντ charged-current and neutral-current (cascade) neutrino interactions. Additionally, a fit for an astrophysical flux with an arbitrary spectral index is performed.
Search for contained neutrino events at energies above 30 TeV in 2 years of data
2013
Neutrino observations are a unique probe of the universe's highest energy phenomena: neutrinos are able to escape from dense environments that photons cannot and are unambiguous tracers of hadronic interaction processes, in particular the acceleration of cosmic rays. We report on results of an all-sky search for these neutrinos at energies above 30 TeV in the cubic kilometer antarctic IceCube observatory between May 2010 and May 2012. The search follows up on the previous detection of two PeV neutrino events, with improved sensitivity and extended energy coverage down to approximately 30 TeV.
IceCube-40 String Data: Searching for a Diffuse Flux of Astrophysical Muon Neutrinos
2011
One of the main strategies used to look for astrophysical neutrinos with IceCube is the search for a diffuse flux of high-energy neutrinos from unresolved sources. A search was performed using data from the IceCube detector collected in its half completed configuration in which 40 strings operated between April 2008 and May 2009. 12,877 candidate neutrino events were obtained from this data sample.
Search for contained neutrino events at energies greater than 1 TeV in 2 years of data
2015
The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV--PeV) neutrinos produced in distant astrophysical objects. Here we present the results of a search for neutrino interactions inside IceCube's instrumented volume between 1 TeV and 1 PeV in 641 days of data taken from 2010--2012. From these data we derive new constraints on the diffuse astrophysical neutrino spectrum,as well as the strongest upper limit yet on the flux of neutrinos from charmed-meson decay in the atmosphere.
Search for sterile neutrinos with one year of IceCube data
2016
The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy to search for the oscillation signatures of light sterile neutrinos. The primary result of this search derives from the first year of data, taken during 2011, of the full 86-string IceCube configuration.
IceCube Oscillations: 3 years muon neutrino disappearance data
2015
In the 1990s, Super-Kamiokande’s measurements of atmospheric neutrinos led to the acceptance of the mass-induced oscillation model. As of today, the three mixing angles, the solar mass splitting and the absolute value of the atmospheric mass splitting that control the oscillation phenomenon have been measured. We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10 GeV and 100 GeV, where a strong disappearance signal is expected.
Exotic properties of neutrinos using effective Lagrangians and specific models
2013
289 páginas. Tesis Doctoral del Departamento de Física Teórica, de la Universidad de Valencia, y del Instituto de Física Corpuscular (IFIC).