3,902 research outputs found

### Scintillation Light Detection with MAPD-3NK and MPPC-S12572-010P Readout

The linearity and energy resolution of two different solid-state photomultipliers (SiPMs) has been studied with reading out the LFS-8 scintillator (3x3x10 mm3). First SiPM (MAPD-3NK) from Zecotek Photonics consists of deeply burned pixels (cells) and has an active area of 3.7x3.7 mm2. The second one (MPPC-S12572-010P) from Hamamatsu has a surface cell structure and an active area of 3x3 mm2. Both SiPMs have the same pixel density of 10000 mmâˆ’2. Energy resolution and linearity of the SiPMs has been studied in the energy range of 59.6-1275 keV. It is found that both SiPMs demonstrate good linearity of signal amplitude as a function of the gamma ray energy in the studied energy range. The detector based on the MAPD-3NK provides significantly good energy resolution in comparison to the detector based on the MPPC-S12572-010P

### Meson Wave Functions From Holographic Qcd And The Role Of Infrared Renormalons In Proton-Proton Collisions

We calculate the contribution of the higher twist Feynman diagrams to the
large-$p_T$ inclusive pion production cross section in proton-proton collisions
in the case of the running and frozen coupling approaches within holographic
QCD. The structure of infrared renormalon singularities of the higher twist
subprocess cross section and it's resummed expression are found. We compare the
resummed higher twist cross sections with the ones obtained in the framework of
the frozen coupling approximation and leading twist cross section. We discuss
the phenomenological consequences of possible higher-twist contributions to the
pion production in proton-proton collisions within holographic QCD.Comment: 19 pages, 14 figures. arXiv admin note: substantial text overlap with
arXiv:1202.2632, arXiv:1107.1562, arXiv:1008.1646, arXiv:0803.019

### Pion wave functions from holographic QCD and the role of infrared renormalons in photon-photon collisions

In this article, we calculate the contribution of the higher-twist Feynman
diagrams to the large-$p_T$ inclusive single pion production cross section in
photon-photon collisions in case of the running coupling and frozen coupling
approaches within holographic QCD. We compare the resummed higher-twist cross
sections with the ones obtained in the framework of the frozen coupling
approach and leading-twist cross section. Also, we show that in the context of
frozen coupling approach a higher-twist contribution to the photon-photon
collisions cross section is normalized in terms of the pion electromagnetic
form factor.Comment: 21 pages, 15 figures. arXiv admin note: text overlap with
arXiv:0709.2072 by other author

### Portable neutron/gamma scintillation detector for status monitoring of accelerator-driven neutron source IREN

Accelerator-driven system (ADS) facilities world-wide opens new opportunities
for nuclear physics investigations, so that a high flux of neutrons through
spallation reactions can be produced at these facilities. It is known that the
measurement, continuous monitoring and optimization of the particle accelerator
beam intensity are among the most important actions in the operation of such
facilities. Considering this point of view, this paper presents a neutron/gamma
counter based on a micropixel avalanche photodiode (MAPD) and a plastic
scintillator that monitors the status of the accelerator-driven intense
resonance neutron source (IREN) facility by measuring the neutron-gamma
intensity in the target hall. The electronics of the modular neutron counter
has been designed and developed, including a bias voltage source (up to 130 V),
a preamplifier (36 gain) and discriminator (>10 mV) circuit. The last product
of MAPD (operation voltage- 55 V, PDE- 33 %, total number of pixels- 136900)
was used as a photon readout from a plastic scintillator. The sensitive area of
MAPD was 3.7*3.7 mm2 and the size of the plastic scintillator 3.7*3.7*30 mm3.
The measurement was carried out in the IREN target hall, where it was necessary
to monitor not only high neutron fluxes, but also gamma quanta. The
experimental results demonstrated a dependence between the count rate of the
detector and the frequency of the accelerator, which ranges from 2 to 50 Hz.Comment: 8 pages, 7 figure

### Contributions of semi-hadronic states $P\gamma;S\gamma, \pi^+\pi^-\gamma$ to amm of muon, in frames of Nambu-Jona-Lasinio model

We calculate the contribution of semi-hadronic states with pseudoscalar
$P=\pi^0, \eta$ and scalar ($\sigma$(550))meson accompanied with real photon as
an intermediate state of a heavy photon to the anomalous magnetic moment of
muon. We consider the intermediate states with $\pi_0$ and $\sigma$ as a
hadrons in frames of Nambu-Jona-Lasinio model. The contribution of
$\pi_0\gamma$ state is in agreement with results obtained in previous
theoretical considerations as well as with experimental data
$a_\mu^{\pi_0\gamma}\approx 4.5 \times 10^{-10}$, besides we estimate
$a_{\mu}^{\eta\gamma}=0.7 \times 10^{-10}, a_{\mu}^{\sigma\gamma} \sim 1.5
\times 10^{-11}, a_{\mu}^{\pi^+\pi^-\gamma} \sim 3.2 \times 10^{-10}.$ We
discass as well the LbL mechanism with $a_{\mu}^{lbl}=10.5 \cdot 10^{-10}.$Comment: 6 pages, 2 figure

### Performance of a plastic scintillator developed using styrene monomer polymerization

This paper presents a newly developed plastic scintillator produced in
collaboration with Turkiye Energy, Nuclear and Mineral Research Agency
(TENMAK). The scintillator is manufactured using thermal polymerization of
commercially available styrene monomer. The absorption spectrum of the
scintillator exhibited two absorption bands at 225 nm and 340 nm, with an
absorption edge observed at 410 nm. The wavelength of the emitted light was
measured in the range of 400-800 nm, with a maximum intensity at 427 nm.
Monoenergetic electrons from the 137Cs source were used to evaluate the
characteristics of the new scintillator, particularly its light yield. As the
light readout the MAPD-3NM type silicon photomultiplier array (4 x 4) with an
active area of 15 x 15 mm2, assembled using single MAPDs with an active area of
3.7 x 3.7 mm2, was used. The light yield of the scintillator was determined to
be 6134 photons/MeV. In addition, the efficiency of the scintillator for gamma
rays with an energy of 662 keV was found to be approximately 1.8 %. A CmBe
neutron source was employed to evaluate its fast neutron detection performance.
However, neutron/gamma discrimination using pulse shape discrimination (charge
integration) method was not observed. The results demonstrate the potential of
a newly produced plastic scintillator for various applications, particularly in
radiation monitoring and detection systems.Comment: 7 pages, 7 figure

### One-loop chiral amplitudes of Moller scattering process

The high energy amplitudes of the large angles Moller scattering are
calculated in frame of chiral basis in Born and 1-loop QED level. Taking into
account as well the contribution from emission of soft real photons the compact
relations free from infrared divergences are obtained. The expressions for
separate chiral amplitudes contribution to the cross section are in agreement
with renormalization group predictions.Comment: 15 pages, 3 figure

### Quantum flux effects on the energy spectra and thermo-magnetic properties in 2D Schrodinger equation with Mobius square potential

A 2D Schrodinger equation with interacting Mobius square potential model is
solved using Nikiforov-Uvarov Functional Analysis (NUFA) formalism. The energy
spectra and the corresponding wave function for the linearly and exponentially
varying quantum magnetic flux are obtained analytically in a closed form. The
evaluated energy spectra are used to obtain an expression for the partition
functions for the two cases comprises of the linearly and exponentially varying
quantum magnetic flux and vis-a-vis is use to evaluate other thermodynamic and
magnetic properties for the system. The results are used to study the free
energy, mean energy, the entropy, specific heat, magnetization, magnetic
susceptibility and the persistent current of the system. The numerical bound
state energies are computed.Comment: 39 Pages, 64 figure

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