Search results for "Alice"
showing 10 items of 106 documents
Upgrade of ALICE forward detectors
2019
ALICE will upgrade its subsystems in 2019−2020 to fully benefit from the increased collision rate and luminosity of the LHC at CERN. Two new forward detectors will be installed at the core of ALICE: the Fast Interaction Trigger (FIT) and the Muon Forward Tracker (MFT). Additionally, during the shutdown between Run 3 and Run 4, there will be an opportunity to install the Forward Calorimeter (FoCal). This paper describes these new forward detectors, their physics justification and goals, selected design features along with performance of detector prototypes and simulated performance figures. peerReviewed
Measurement of the low-energy antideuteron inelastic cross section
2020
In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of $0.3 \leq p < 4$ GeV/$c$. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the GEANT4 toolkit for the propagation of antiparticles through the detector material. The analysis of th…
Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC
2020
The study of the strength and behaviour of the antikaon-nucleon ($\mathrm{\overline{K}N}$) interaction constitutes one of the key focuses of the strangeness sector in low-energy Quantum Chromodynamics (QCD). In this letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K$^+$ p $\oplus$ K$^-$ $\overline{\mathrm{p}}$) and (K$^-$ p $\oplus$ K$^+$ $\overline{\mathrm{p}}$) pairs measured in pp collisions at $\sqrt{s}$ = 5, 7 and 13 TeV are reported. A structure observed around a relative momentum of 58 Me…
Study of very forward energy and its correlation with particle production at midrapidity in pp and p-Pb collisions at the LHC
2022
Journal of high energy physics 08(8), 86 (2022). doi:10.1007/JHEP08(2022)086
First Observation of an Attractive Interaction between a Proton and a Cascade Baryon
2019
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ−. The result is extracted from two-particle correlations of combined p−Ξ−⊕¯p−¯Ξ+ pairs measured in p−Pb collisions at √sNN=5.02 TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a stand…
Bildning as a Central Concept in the Cultural Policy of the Swedish Government : From Arthur Engberg to Alice Bah Kuhnke
2015
This article explores bildning as a central concept in the development of the explicit cultural policy of the Swedish government. It takes its point of departure in how the concept of bildning was interpreted by Arthur Engberg, the minister responsible for cultural policy in the Social Democrat governments 1932–1939. In his interpretation bildning was liked both to upholding the high arts and the national culture and to the idea of re-invigorating these through cultural policy and education. The article continues by looking at the role and the interpretations of this concept in the later government reports and government bills aiming to cover the entirety of Swedish cultural policy, i.e. th…
Direct observation of the dead-cone effect in quantum chromodynamics.
2022
In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD)1. These partons subsequently emit further partons in a process that can be described as a parton shower2, which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a he…
Real-time data processing in the ALICE High Level Trigger at the LHC
2019
At the Large Hadron Collider at CERN in Geneva, Switzerland, atomic nuclei are collided at ultra-relativistic energies. Many final-state particles are produced in each collision and their properties are measured by the ALICE detector. The detector signals induced by the produced particles are digitized leading to data rates that are in excess of 48 GB/$s$. The ALICE High Level Trigger (HLT) system pioneered the use of FPGA- and GPU-based algorithms to reconstruct charged-particle trajectories and reduce the data size in real time. The results of the reconstruction of the collision events, available online, are used for high level data quality and detector-performance monitoring and real-tim…
Multiplicity dependence of the average transverse momentum in pp, p–Pb, and Pb–Pb collisions at the LHC
2013
The average transverse momentum $\langle p_{\rm T}\rangle$ versus the charged-particle multiplicity $N_{\rm ch}$ was measured in p-Pb collisions at a collision energy per nucleon-nucleon pair $\sqrt{s_{\rm NN}}=5.02$ TeV and in pp collisions at collision energies of $\sqrt{s}=0.9$, 2.76, and 7 TeV in the kinematic range $0.15<p_{\rm T}<10.0$ GeV/$c$ and $|\eta|<0.3$ with the ALICE apparatus at the LHC. These data are compared to results in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV at similar charged-particle multiplicities. In pp and p-Pb collisions, a strong increase of $\langle p_{\rm T}\rangle$ with $N_{\rm ch}$ is observed, which is much stronger than that measured in Pb-Pb colli…
Atlantin ylityksiä : amerikkalaisen kirjallisuuden- ja kulttuurintutkimuksen navigointia 1965-1995
2011
Teoriat muuttuvat paitsi aikaa myös paikkaa myöten. Kirjassa tutkitaan eurooppalaisen, varsinkin ranskalaisen teorian Atlantin ylityksiä. Millaisiksi eräät keskeiset teoriaotteet muotoutuivat yhdysvaltalaisessa yliopistomaailmassa ja kohdatessaan uudet poliittiset ja kulttuuriset haasteet? Tämän muotoutumisen vaikutukset näkyvät vuorostaan muualla. Ajanjakso on 1965–1995. "Korkean teorian" nousu liittyi kielelliseen käänteeseen ja perustojen horjumiseen, ja sen erilaisten muotojen ja myös vastustamisen tarkastelu ulottuu kielen merkityksiä hajottavasta retorisuudesta valtarakenteiden marxilaiseen analyysiin, afrikkalaisamerikkalaiseen feminismiin ja "orientalismin" symboliseen tuottamiseen …