Search results for "Particle physics"
showing 10 items of 6826 documents
Chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes-Renner relation
2010
The next to leading order chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes- Renner (GMOR) relation are obtained using the pseudoscalar correlator to five-loop order in perturbative QCD, together with new finite energy sum rules (FESR) incorporating polynomial, Legendre type, integration kernels. The purpose of these kernels is to suppress hadronic contributions in the region where they are least known. This reduces considerably the systematic uncertainties arising from the lack of direct experimental information on the hadronic resonance spectral function. Three different methods are used to compute the FESR contour integral in the complex energy (squared) s-plane, i.e. Fixed Order P…
Phenomenology of precarity
2021
Edmund Husserl’s phenomenological method has mostly been applied to epistemological questions. However, it also has great potential for analysing phenomena of social and political relevance. This text outlines a phenomenology of social precariousness, showing how it impacts the experiential, temporal, perceptual and self-perceptual structures of the subject, thereby influencing intergenerational relations.
Measurement of upsilon production in 7 TeV pp collisions at ATLAS
2013
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM
TeV particle direct detection in space - Recent results from the DAMPE mission
2019
Since its successful launch to a Low Earth Orbit in December 2015, the DAMPE (DArk Matter Particle Explorer) satellite mission has been preforming excellently, which allows the experiment to collect a large high quality data sample of high energy cosmic rays directly in space. With a relatively large acceptance, a thick BGO homogeneous calorimeter, and a precise silicon tracker, DAMPE is designed to measure multi-TeV particles in space with unprecedented precision. A first measurement of electron plus positron total flux up to 4.6 TeV based on the first 18 months of data has been published. Other results, including proton and Helium fluxes up to 100 TeV/nucleon, are becoming available. In t…
Search for new particles in two-jet final states in 7 TeV proton-proton collisions with the ATLAS detector at the LHC
2010
19 páginas, 2 figuras, 1 tabla.-- et al.(ATLAS Collaboration).
A Collective Coordinate to Obtain Free Energy Profiles for Complex Reactions in Condensed Phases.
2015
Exploration of chemical reactions in complex explicit environments has become an affordable task with the use of hybrid quantum mechanics/molecular mechanics potentials which allow calculating free energy profiles of chemical reactions under the influence of the surroundings. Tracing these free energy profiles requires the selection of a reaction coordinate, which can be cumbersome for those processes involving more than a single chemical event in a concerted step. We here propose a collective coordinate to be used in the calculation of free energy profiles for complex reactions in condensed phases. This coordinate is based in the definition of the advance along a path introduced by Brandua…
Antiproton over proton and K$^-$ over K$^+$ multiplicity ratios at high $z$ in DIS
2020
The $\bar{\rm p} $ over p multiplicity ratio is measured in deep-inelastic scattering for the first time using (anti-) protons carrying a large fraction of the virtual-photon energy, $z>0.5$. The data were obtained by the COMPASS Collaboration using a 160 GeV muon beam impinging on an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2$ > 1 (GeV/$c$)$^2$ for the photon virtuality and $W > 5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. The range in Bjorken-$x$ is restricted to $0.01 < x < 0.40$. Protons and antiprotons are identified in the momentum range $20 ��60$ GeV/$c$. In the whole studied $z$-region, the $\…
Measurement of visible cross sections in proton-lead collisions at √sNN= 5.02 TeV in van der Meer scans with the ALICE detector
2014
In 2013, the Large Hadron Collider provided proton-lead and lead-proton collisions at the center-of-mass energy per nucleon pair $\sqrt{s_{\rm{NN}}}=5.02$ TeV. Van der Meer scans were performed for both configurations of colliding beams, and the cross section was measured for two reference processes, based on particle detection by the T0 and V0 detectors, with pseudo-rapidity coverage $4.6<\eta< 4.9$, $-3.3<\eta<-3.0$ and $2.8<\eta< 5.1$, $-3.7<\eta<-1.7$, respectively. Given the asymmetric detector acceptance, the cross section was measured separately for the two configurations. The measured visible cross sections are used to calculate the integrated luminosity of the proton-lead and lead-…
Measurement of multi-jet cross sections in proton-proton collisions at a 7 TeV center-of-mass energy
2011
Inclusive multi-jet production is studied in proton–proton collisions at a center-of-mass energy of 7 TeV, using the ATLAS detector. The data sample corresponds to an integrated luminosity of 2.4 pb−1. Results on multi-jet cross sections are presented and compared to both leading-order plus parton-shower Monte Carlo predictions and to next-to-leading-order QCD calculations.