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1.
R. Lednicky 《Physics of Atomic Nuclei》2008,71(9):1514-1517
One of the basic facilities at the Joint Institute for Nuclear Research (JINR) in Dubna is the 6 A GeV Nuclotron, which has replaced the old weak focusing 10-GeV proton accelerator Synchrophasotron. The first relativistic
nuclear beams with the energy of 4.2 A GeV were obtained at the Synchrophasotron in 1971. Since that time, relativistic nuclear physics has been one of the main
directions of the JINR research program. In the coming years, the new JINR flagship program assumes the experimental study
of hot and dense strongly interacting QCD matter at the new JINR facility. This goal is proposed to be reached by (i) development
of the existing Nuclotron accelerator facility as a basis for generation of intense beams over atomic mass range from protons
to uranium and light polarized ions, (ii) design and construction of the Nuclotron-based heavy Ion Collider fAcility (NICA)
with the maximum nucleon-nucleon center-of-mass collision energy of √s
NN
= 9 GeV and averaged luminosity 1027 cm−2 s−1, and (iii) design and construction of the Multipurpose Particle Detector (MPD) at intersecting beams. Realization of the
project will lead to unique conditions for research activity of the world community. The NICA energy region is of major interest
because the highest nuclear (baryonic) density under laboratory conditions can be reached there. Generation of intense polarized
light nuclear beams aimed at investigation of polarization phenomena at the Nuclotron is foreseen.
The text was submitted by the author in English. 相似文献
2.
A. V. Eliseev I. N. Meshkov V. A. Mikhailov A. O. Sidorin 《Physics of Particles and Nuclei Letters》2010,7(7):473-477
The main objective of the NICA project developed at the Joint Institute for Nuclear Research (JINR) is to conduct experimental
studies with colliding heavy ion beams in an energy range of 1–4.5 GeV/nucleonucleon with luminosity on the level of 1 × 1027 cm−2 s−1. In this paper the operation regime of the collider injection chain providing the bunch with experimentally desirable parameters
at the output of the Nuclotron is considered for gold ions as an example. 相似文献
3.
Comparative studies of the emission of quasi-thermal atomic and cluster ions from V, Nb, Ta, Au, and In targets bombarded
by cluster ions Au
m
−(m = 1–9), as well as from Si and Bi targets bombarded by cluster ions Au
m
−(m = 1–9) and Bi
m
−(m = 1–5), with energy E
0 ranging from 6 to 21 keV are carried out. In the case of bombardment by heavy cluster ions, the fraction of the quasi-thermal
component in the energy spectra of sputtered atomic ions reaches 50 (for V, In, and Au), 70 (Nb), or more than 90% (Ta). In
addition, quasi-thermal ions play a considerable part in the emission of small cluster ions Au2+, In2+, In3+, and Bi
n
+(n = 2–7). The results of the generalizing investigation favor the presence of thermal spike conditions at cluster bombardment
and their appreciable contribution to the emission of atomic and small cluster ions. 相似文献
4.
S. N. Morozov U. Kh. Rasulev 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(7):902-905
The mass spectra of secondary cluster ions Bi
n
+ (n = 1–9) from bismuth sputtered by (6–21) keV Au
m
− (m = 1–9) and Bi
m
− (m = 1–5) cluster ions have been investigated. New features of manifestation of dense nonlinear cascades and thermal spikes
have been revealed. It is concluded that the thermal spike regime makes a significant contribution to the mechanism of formation
of small cluster ions, containing up to seven atoms for a bismuth target. 相似文献
5.
A large stack of lead-emulsion sandwich detector assembly was flown over Hyderabad, India. High energy gamma rays at the float
altitude were unambiguously identified from the cascades they induced, and their energies reliably determined by improved
methods. From an analysis of 163 gamma rays of energy ≳ 30 GeV, it is found that the differential energy spectrum is represented
by the power lawJ
r
(E)= 129·4E
−2·62±0·12 photons m−2 sr−1sec−1 GeV−1 at an effective atmospheric depth of 14·3 g cm−2; this is the first reliable balloon measurement of atmospheric gamma rays in the energy range 40–1000 GeV. After correcting
for the gamma rays radiated by the primary cosmic ray electrons, the production spectrum of gamma rays, resulting from the
collisions of cosmic ray nuclei with air nuclei, at the top of the atmosphere isP
r
(E, 0)=8·2 × 10−4 E2.60±0.09 photons g−1sr−1sec−1 GeV−1. The atmospheric propagation of the electromagnetic component due to the cascade process is also derived from the gamma ray
production spectrum. 相似文献
6.
Y. Ming 《Indian Journal of Physics》2011,85(6):861-865
The Time-of-Flight detector, based on MRPC technology, has greatly enhanced particle identification capability in STAR. By
combining dE/dx measured by the TPC and velocity information from the TOF, we have extended the charged kaon transverse momentum spectra
measurements up to ρ
T
− 5 GeV/c at mid-rapidity for Au+Au collisions at ?{sNN }\sqrt {s_{NN} } = 200 GeV. Estimation of charged kaon’s contribution factors from K* and ϕ is also made. 相似文献
7.
The e
+
e
− → π
+
π
−
π
+
π
− cross section is calculated for energies of 0.65 ≤ √s ≤ 1 GeV in the framework of the generalized hidden local symmetry model. The calculations are compared with the data of CMD-2
and BaBaR. It is shown that the inclusion of heavy isovector resonances ρ(1450) and ρ(1700) is necessary for reconciling calculations
with the data. It is found that, at √s ≈ 1 GeV, the contributions of the above resonances are much larger, by a factor of 30, than the ρ(770) one, and amount to
a considerable fraction ∼0.3–0.6 of the latter at √s ∼ m
ρ.
The text was submitted by the authors in English. 相似文献
8.
We present the discovery potential for heavy Z′ gauge bosons in the Z′→e
+
e
− decay channel at the Large Hadron Collider. The analysis focuses on the direct search for the massive Z′ bosons predicted by the Stueckelberg extension of the Standard Model. Using signal and background simulated events, and
taking into account the basic parameters of the Compact Muon Solenoid detector, the discovery reach for the Stueckelberg Z′ is found to be in the range between 800 and 900 GeV/c2 for an integrated luminosity of 30 fb−1. 相似文献
9.
J.?G.?Due?as N.?Gutierrez R.?Martínez F.?Ochoa 《The European Physical Journal C - Particles and Fields》2009,60(4):653-659
We analyse the possibilities to detect a new Z
′ boson in di-electron events at Tevatron and LHC in the framework of the 331 model with right-handed neutrinos. We also study
other fermions and Higgs events as final state at LHC. Using
collision data collected by the CDF II detector at Fermilab Tevatron, we find that the 331 Z
′ boson is excluded with masses below 920 GeV. For an integrated luminosity of 100 fb−1 at LHC, and considering a central value
GeV, we obtain the invariant-mass distribution in the process pp→Z
′→e
+
e
−, where a huge peak, corresponding to 800 signal events/(20 GeV), is found above the SM background. The number of di-electron
events vary from 50000 to 2400 in the mass range of
–2000 GeV. We also obtain branching ratios and cross sections in other fermion and Higgs channels at LHC, where a heavy top
quark T exhibits the biggest ratio with m
T
=300 GeV. 相似文献
10.
Connected two-point field-strength correlation functions are measured on a lattice in the quaternionic projective σ model within pure SU(2) theory. The correlation lengths extracted from exponential fits for these correlation functions, λ1−1 = 1.40(3) GeV and λ−1 = 1.51(3) GeV, are found to be in good agreement with the results of other known calculations. The dependence of bilocal
functions on the connector shape is also studied. 相似文献
11.
Summary A search has been made for excesses of cosmic-ray counting rates at primary energiesE
01>5 GeV andE
04>2·104 GeV over the time scalet=(1÷100) ms. The measurement was performed by means of a small extensive air shower array operating at mountain altitude (3500
m a.s.l.). During the running time 111 cosmic gamma-ray bursts were detected by satellites; 10 of them certainly (55 probably)
above the horizon of the detector. No significant counting rate excess has been recorded out of the statistical fluctuations.
Also the search for correlations with satellite events has given a negative result. The upper limit for high-energy cosmic
gamma-ray flux in bursts isϕ
1(E>E
01)<4·10−5 (t = time scale in ms),ϕ
4(E>E
04)<1.6·10−5erg/cm2.
Paper presented at the 2o Convegno Nazionale di Fisica Cosmica, held at L'Aquila, 29 May–2 June 1984. 相似文献
12.
13.
R. Brandt V. A. Ditlov K. K. Dwivedi W. Ensinger E. Ganssauge Guo Shi-Lun M. Haiduc S. R. Hashemi-Nezhad H. A. Khan M. I. Krivopustov R. Odoj E. A. Pozharova V. A. Smirnitzki A. N. Sosnin W. Westmeier M. Zamani-Valasiadou 《Physics of Particles and Nuclei》2008,39(2):259-285
Interactions of relativistic heavy ions with total energies above 30 GeV in thick Cu and Pb targets (≥ 2 cm) have been studied
with various techniques. Radiochemical irradiation experiments using thick Cu targets, both in a compact form or as diluted
“2π-Cu targets” have been carried out with several relativistic heavy ions, such as 44 GeV 12C (JINR, Dubna, Russia) and 72 GeV 40Ar (LBL, Berkeley, USA). Neutron measuring experiments using thick targets irradiated with various relativistic heavy ions
up to 44 GeV 12C have been performed at the JINR. In addition, the number of “black prongs” in nuclear interactions (due to protons with
energies less than 30 MeV and emitted from the target-like interaction partner at rest) produced with 72 GeV 22Ne ions in nuclear emulsion plates has been measured in the first nuclear interaction of the primary 22Ne ion and in the following second nuclear interaction of the secondary heavy (Z > 1) ion. Some essential results have been obtained. (1) Spallation products produced by relativistic secondary fragments
in interactions ([44 GeV 12C or 72 GeV 40Ar] + Cu) within thick copper yield fewer products close to the target and many more products far away from the target as
compared to primary beam interactions. This applies also to secondary particles emitted into large angles (Θ > 10°). (2) The
neutron production of 44 GeV 12C within thick Cu and Pb targets is beyond the estimated yield as based on experiments with 12 GeV 12C. These rather independent experimental results cannot be understood within well-accepted nuclear reaction models. They appear
to present unresolved problems.
The text was submitted by the authors in English. 相似文献
14.
M. Aglietta B. Alessandro P. Antonioli F. Arneodo L. Bergamasco A. Campos Fauth C. Castagnoli A. Castellina C. Cattadori A. Chiavassa et al. 《Il Nuovo Cimento C》1992,15(4):441-446
Summary A search for cosmic gamma-ray bursts in the GeV energy range has been performed by means of the EAS-TOP Extensive Air Shower
array at Campo Imperatore (Gran Sasso Laboratories) during the period March–December 1990. In 2566.5 hours of measurement
the obtained upper limit to the rate of bursts of amplitude >2% of the cosmic-ray intensity and time duration τ=1 s, isR≤7.9y−1 (90% c.l.). Assuming for γ-rays a differential energy spectrumS(E
0
)≈E
0
−2.5
, the corresponding upper limit to the energy flux of γ-rays with energy >5 GeV in bursts of duration τ≤1 s is Φ<8.3·10−5erg cm−2. 相似文献
15.
M. O. Vlasova N. D. Galanina V. S. Demidov A. A. Nedosekin A. Ya. Ostapchuk V. A. Sadykov N. A. Khaldeeva A. L. Endalov M. A. Martem’yanov A. K. Ponosov F. M. Sergeev M. Yu. Tel’nov 《JETP Letters》1996,64(4):258-262
The polarization of the leading Λ hyperons produced on carbon and lead target nuclei by 4–10 GeV neutrons in the angle range
Θ<8.5° with respect to the beam and with only neutral-particle accompaniment is measured: 〈Π〉=−0.096±0.018 for C and 〈Π〉=−
0.128±0.047 for Pb. The dependence of the polarization on the transverse momentum and the Feynman variable is measured. The
normalized invariant cross section as a function of p
⊥
2
is found to be approximated by the function A exp(−Bp
⊥
2
), where the parameter B is independent of the kind of nucleus (B=8.71±0.09 (GeV/c)−2 for carbon and B=8.83±0.18 (GeV/c)−2 for lead).
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 4, 237–240 (25 August 1996) 相似文献
16.
S. Yu. Paranchich L. D. Paranchich M. D. Andriichuk V. R. Romanyuk V. N. Makogonenko Yu. V. Tanasyuk T. A. Mel’nichuk 《Journal of Applied Spectroscopy》2007,74(1):81-85
We present the results of experimental studies of the optical properties of cobalt-doped Cd
x
H1−x
Se (x = 0.18) single crystals with cobalt ion concentrations of NCo = 5·1018, 5·1019, and 1·1020 cm−3 at T = 90 K and 300 K. The composition (x = 0.18) of the Cd
x
Hg1−x
Se solid solution was selected so that the hypothetical resonance level is found on the bottom of the conduction band. We
show that the cobalt ions in the mercury selenide can form a resonance donor level only for cobalt concentrations NCo < 5·1018 cm−3. For NCo ∼ 5·1018 cm−3, the cobalt ions substitute for mercury atoms, forming a solid solution and leading to an increase in the bandgap width and
a change in the physical properties. The solubility of cobalt in the HgSe lattice can be greater than 5%–10%.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 73–77, January–February, 2007. 相似文献
17.
《Physics of Atomic Nuclei》2004,67(6):1161-1171
The present status of the Baikal Neutrino Experiment and the present results of a search for upward going atmospheric neutrinos,
WIMPs, and magnetic monopoles obtained with the NT-200 detector are reviewed. The results of a search for very high-energy
neutrinos are presented as well. An upper limit on the ν
e
+ν
e
+ν
τ
neutrino diffuse flux of E
2Φ(E)<1.3×10−6 cm−2 s−1 sr−1 GeV within a neutrino energy range of 104–107 GeV is obtained, assumingan E
−2 behavior of the neutrino spectrum and a flavor ratio ν
e
:ν
π
:ν
τ
=1:1:1. We also describe the moderate upgrade of the NT-200 planned for the next few years and present a possible detector
on the Gigaton scale.
From Yadernaya Fizika, Vol. 67, No. 6, 2004, pp. 1186–1194.
Original English Text Copyright ? 2004 by Aynutdinov, Balkanov, Belolaptikov, Bezrukov, Budnev, Chensky, Chernov, Danilchenko,
Dzhilkibaev, Domogatsky, Dyachok, Gaponenko, O. Gress, T. Gress, Klabukov, Klimov, Klimushin, Konischev, Koshechkin, Kulepov,
Kuzmichev, Kuznetzov, Lubsandorzhiev, Mikheyev, Milenin, Mirgazov, Moiseiko, Osipova, Panfilov, G. Pan'kov, L. Pan'kov, Parfenov,
Pavlov, Pliskovsky, Pokhil, Polecshuk, Popova, Prosin, Rosanov, Rubtzov, Semeney, Shaibonov, Spiering, Streicher, Tarashansky,
Vasiliev, Vyatchin, Wischnewski, Yashin, Zhukov.
This article was submitted by the authors in English. 相似文献
18.
Mark A. Thomson 《Pramana》2007,69(6):1101-1107
One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that
the particle flow approach to calorimetry is the key to achieving the goal of 0.3/√E(GeV). This paper describes the current performance of the PandoraPFA particle flow algorithm. For 45 GeV jets in the Tesla TDR detector concept, the ILC jet energy resolution goal is reached.
At higher energies the jet energy resolution becomes worse and can be described by the empirical expression: σ
E
/E ≈ 0.265/√E(GeV) + 1.2 × 10−4
E(GeV).
相似文献
19.
Yu. N. Uzikov 《JETP Letters》2005,81(7):303-306
It is shown that the differential cross sections of the reactions dd → n
3He and dd → p
3H measured at a c.m.s. scattering angle θcm = 60° in the interval of the deuteron beam energy 0.5–1.2 GeV demonstrate the scaling behavior dσ/dt ∼ s
−22, which follows from constituent quark counting rules. It is found also that the differential cross section of the elastic
dp → dp scattering at θcm = 125°–135° follows the scaling regime ∼s
−16 at beam energies 0.5–5 GeV. These data are parameterized here using the Reggeon exchange.
From Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, Vol. 81, No. 7, 2005, pp. 387–390.
Original English Text Copyright ? 2005 by Uzikov.
This article was submitted by the author in English. 相似文献
20.
The angular dependences of the electron spin resonance spectrum of 1% Ni2+ ions in a ZnSiF6·6H2O matrix are investigated experimentally at 36 GHz and 4.2 K. Besides the main spectrum of the isolated ion, we observed a
spectrum due to interacting pairs of Ni2+ ions, located in the first (nn) and second (2n) coordination spheres and coupled by, besides the magnetic dipole-dipole interaction, isotropic exchange: J
nn
= (−197±1)×10−4, J
2nα
= (−5±1)×10−4, and J
2nβ
= (3±2)×10−4 cm−1. Lines due to other isolated Ni2+ ions, which have a different initial splitting D, are also present in the spectrum with intensity comparable to the pair spectrum. Low-symmetry distortions of the crystal
field are observed, caused by a pair of impurity ions located close to one another. It is shown that the previously proposed
interpretation is incorrect.
Fiz. Tverd. Tela (St. Petersburg) 41, 1602–1608 (September 1999) 相似文献