Search results for "väri"

Next-to-leading order perturbative QCD predictions for exclusive J/ψ photoproduction in oxygen-oxygen and lead-lead collisions at energies available …

2023

We present predictions for the cross sections of coherent J/ψ photoproduction in lead-lead and oxygen-oxygen ultraperipheral collisions (UPCs) as a function of the J/ψ rapidity at the LHC in the framework of collinear factorization at next-to-leading order (NLO) in perturbative QCD. Taking generalized parton distribution functions in their forward limit and using the EPPS21, nNNPDF3.0, and nCTEQ15WZSIH nuclear parton distribution functions, we update our recent results for Pb-Pb collisions, make detailed predictions for O-O collisions for several beam energy configurations, and examine the ratio of O-O and Pb-Pb UPC cross sections. We show that the latter observable allows one to significan…

Exclusive J/ψ and ϒ production in high-energy pp and p-Pb collisions

2022

We present a formalism for determining the cross section for exclusive heavy vector meson production (J/ψ,ϒ) as a function of rapidity, in both high-energy proton-proton and proton-heavy ion collisions, at next-to-leading order in QCD. We compare and contrast the production in pp and p-Pb collisions and show how data for these processes can give information on the low-x gluon distribution of the proton and heavy ions at a range of different scales.

Multiplicity dependence of charged-particle jet production in pp collisions at √s = 13 TeV

2022

The multiplicity dependence of jet production in pp collisions at the centre-of-mass energy of √s=13 TeV is studied for the first time. Jets are reconstructed from charged particles using the anti-kT algorithm with resolution parameters R varying from 0.2 to 0.7. The jets are measured in the pseudorapidity range |ηjet|<0.9−R and in the transverse momentum range 5<140 GeV/c. The multiplicity intervals are categorised by the ALICE forward detector V0. The pT differential cross section of charged-particle jets are compared to leading order (LO) and next-to-leading order (NLO) perturbative quantum chromodynamics (pQCD) calculations. It is found that the data are better described by the NLO calc…

Exclusive J/ψ photoproduction in ultraperipheral Pb+Pb collisions at the CERN Large Hadron Collider calculated at next-to-leading order perturbative …

2022

We present the first next-to-leading-order (NLO) perturbative QCD (pQCD) study of rapidity-differential cross sections of coherent exclusive photoproduction of J/ψ mesons in heavy-ion ultraperipheral collisions (UPCs) at the CERN Large Hadron Collider (LHC), dσ/dy(Pb+Pb→Pb+J/ψ+Pb). For this, we account for the photon-nucleon NLO cross sections at the forward limit, the t dependence using a standard nuclear form factor, and the photon fluxes of the colliding nuclei. Approximating the generalized parton distributions with their forward-limit parton distribution functions (PDFs), we quantify the NLO contributions in the cross sections, show that the real part of the amplitude and quark-PDF con…

Proton Structure Functions at Next-to-Leading Order in the Dipole Picture with Massive Quarks

2023

We predict heavy quark production cross sections in deep inelastic scattering at high energy by applying the color glass condensate effective theory. We demonstrate that, when the calculation is performed consistently at next-to-leading order accuracy with massive quarks, it becomes possible, for the first time in the dipole picture with perturbatively calculated center-of-mass energy evolution, to simultaneously describe both the light and heavy quark production data at small xBj. Furthermore, we show how the heavy quark cross section data provides additional strong constraints on the extracted nonperturbative initial condition for the small-xBj evolution equations.

New Constraints of QCD Matter from Bayesian Parameter Estimation with LHC Data

2022

New constraints of QCD matter from improved Bayesian parameter estimation with the latest LHC data

2022

Transport properties of the matter created in heavy-ion collisions, the quark-gluon plasma (QGP), contain essential information about quantum chromodynamics (QCD). In this talk, we present our latest study in inferring the transport properties of QGP by an improved Bayesian analysis using the CERN Large Hadron Collider Pb-Pb data. The uncertainties of the extracted properties are reduced by adding new observables sensitive to specific shear and bulk viscosity, reflecting mostly nonlinear hydrodynamic responses. The analysis also reveals that higher-order harmonic flows and their correlations have a higher sensitivity to the transport properties than other observables. This observation shows…

Improving Bayesian parameter estimation with the latest RHIC and LHC data including a new initial conditions model

2023

Extreme Metal -riffit tarkastelussa: kämmensyrjävaimennus musiikin muodon artikuloijana

2012

Metal-musiikissa särötetty sähkökitara on standardi. Niin myös kämmensyrjävaimennus. Kämmensyrjävaimennusta (engl. palm-mute) on käytetty jo vuosikymmeniä heavy metal ja extreme metal -musiikin riffeissä. Kämmensyrjävaimennus on kitaransoittotekniikka, jossa soittokäden kämmenen takaosa lepää kitaran kielen päällä tallan kohdalla. Kyseistä soittotekniikkaa käytetään myös muissa populaarimusiikin tyyleissä, kuten funkissa ja soulissa. Vaikka tekniikan nimessä on sana "vaimennus", ei sen tarkoitus ole hiljentää sähkökitaran sointia. Kämmensyrjävaimennus tekee kitaran soinnista staccatomaista ja perkussiivisempaa. Kämmensyrjävaimennus saa aikaan muutoksia musiikin soitinvärissä ja rytmiikassa.…

Auditiivisen palautteen häiritsemisen vaikutus mieslaulajan sävelkorkeuteen ja äänenväriin

2010

Aiemmassa tutkimuksessa on osoitettu, että laulajan säveltarkkuus heikkenee kun hänen auditiivista palautejärjestelmäänsä häiritään. Aiemmissa kokeissa koetehtävinä on käytetty sointuarpeggioita sekä asteikkoja, jolloin sävelen kontekstisidonnaisuus on jäänyt vähemmälle huomiolle. Tässä tutkimuksessa haluttiin eksperimentin avulla selvittää kuinka tarkastelusävelen konteksti vaikuttaa sävelkorkeuden vaihteluihin, kun koehenkilöiden auditiivista palautejärjestelmää häiritään. Koetehtävät olivat lyhyitä melodioita sekä tuttu lastenlaulu. Koehenkilöt olivat miehiä. Selvisi, että ylhäältä päin lähestyttäessä kohdesävelen sävelkorkeus on selvästi matalampi kuin alhaalta päin lähestyttäessä. Saat…