Search results for "Fysiikka"

Transfer reactions in 206Pb+118Sn: From quasielastic to deep-inelastic processes

2023

We measured multinucleon transfer reactions for the 206Pb+118Sn system at Elab=1200 MeV by employing the large solid angle magnetic spectrometer PRISMA. Differential and total cross sections and Q-value distributions have been obtained for a variety of neutron and proton pick-up and stripping channels. The Q-value distributions show how the quasielastic and deep inelastic processes depend on the mass and charge of the transfer products. The corresponding cross sections have been compared with calculations performed with the grazing code. An overall good agreement is found for most of the few nucleon transfer channels. The underestimation of the data for channels involving a large number of …

Study of non-fusion products in the 50Ti + 249Cf reaction

2018

Physics letters / B B 784, 199 - 205 (2018). doi:10.1016/j.physletb.2018.07.058

Ainereaaliuudistuksen vaikutus fysiikanopiskelija-ainekseen

2009

Exact solutions of a Dirac equation with a varying CP-violating mass profile and coherent quasiparticle approximation

2015

Tässä pro gradu -tutkielmassa tarkastellaan aikariippuvan taustan omaavan Wightmanin funktion faasiavaruuden rakennetta. Aluksi esittelemme koherentin kvasihiukkasapproksimaation (cQPA), joka on epätasapainoilmiöiden tutkimiseen soveltuva lähestymistapa äärellisen lämpötilan kenttäteoriaan. Osoitamme cQPA:n avulla, että jos tarkastelemme systeemiä, joka ei ole translaatioinvariantti, sen faasiavaruudessa on perinteisten massakuoria vastaavien hiukkas- ja antihiukkasratkaisujen lisäksi uudenlaista rakennetta. Tämä hiukkasten välistä epälokaalia kvanttikoherenssia kuvaava rakenne ilmenee nollaliikemääräkuorella k_0 = 0. Seuraavaksi otamme tarkasteltavaksemme ongelman, jossa koherenssirakentee…

High-precision measurement of a low Q value for allowed β−-decay of 131I related to neutrino mass determination

2022

The ground-state-to-ground-state β−-decay 131I (7/2+) → 131Xe (3/2+) Q value was determined with high precision utilizing the double Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. The Q value of this β−-decay was found to be Q = 972.25(19) keV through a cyclotron frequency ratio measurement with a relative precision of 1.6 × 10−9. This was realized using the phase-imaging ion-cyclotron-resonance technique. The new Q value is more than 3 times more precise and 2.3σ higher (1.45 keV) than the value extracted from the Atomic Mass Evaluation 2020. Our measurement confirms that the β−-decay to the 9/2+ excited state at 971.22(13) keV in 131Xe is energetically allowed with a Q va…

Evidence against the wobbling nature of low-spin bands in 135Pr

2021

International audience; The electromagnetic character of the ΔI=1 transitions connecting the 1- to 0-phonon and the 2- to 1-phonon wobbling bands should be dominated by an E2 component, due to the collective motion of the entire nuclear charge. In the present work it is shown, based on combined angular correlation and linear polarization measurements, that the mixing ratios of all analyzed connecting transitions between low-lying bands in 135Pr interpreted as 0-, 1-, and 2-phonon wobbling bands, have absolute values smaller than one. This indicates predominant M1 magnetic character, which is incompatible with the proposed wobbling nature. All experimental observables are instead in good agr…

Study of the neutral pion and direct photon production in Au+Au collisions at √sNN = 39-200 GeV

2013

This thesis focuses on the study of the neutral pion and eta production in the Au+Au “low-energy”collisions at √sNN = 39 and 62.4 GeV.The η/π0 ratio was reconstructed in Au+Au minimum bias collisions at √sNN = 62.4 GeV up to pT < 7 GeV/c. The direct photons were reconstructed via the subtraction method using two different PID cuts up to pT < 10 GeV/c in Au+Au minimum bias collisions at √sNN = 62.4 GeV.

Underground investigation of extensive air showers spectra at high energy range of cosmic rays and other research in the Pyhäsalmi mine

2020

Abstract High energy particles reaching the Earth’s atmosphere are known as cosmic rays. As a result of interactions with nuclei of air molecules, cosmic rays induce showers of secondary particles, which can be divided into 3 components: electromagnetic, hadronic and muonic components. The Experiment with Multi Muon Array (EMMA), located at the depth of 75 m in the Pyhäsalmi mine in Finland, investigates the muonic component of the Extensive Air Showers (EAS) to deduce the direction, energy, and the mass of the primary cosmic ray particles. In this paper we give a concise description and methodology used by EMMA followed by a brief review of the C14 experiment. Finally, we review the feasib…