共查询到20条相似文献,搜索用时 437 毫秒
1.
G. V. Domogatsky V. I. Kopeikin L. A. Mikaelyan V. V. Sinev 《Physics of Atomic Nuclei》2006,69(11):1894-1898
Antineutrinos born in the U and Th decay chains inside the Earth (geoneutrinos) carry information on the amount and distribution
of radiogenic heat sources, which is of fundamental importance for geophysics. Models of the Earth distribute U and Th masses
mainly between the continental crust and the lower mantle. It has been much discussed recently that a number of detectors
stationed at appropriate geographical sites can separate the crust and mantle contributions. We analyze directional separation
of
signals arriving from the crust and the lower mantle with only one detector. We find that, with an ∼ 30-kt liquid scintillation
antineutrino spectrometer using the
+ p → e
+ + n detection reaction and positron and neutron coordinate reconstruction techniques, the U and Th distribution model can roughly
be tested. We also consider detector calibration using an ∼ 1-MCi commercially available 90Sr-90Y beta source which emits
(E
ν,max = 2.28 MeV) in the geoneutrino energy range.
The text was submitted by the authors in English.
Also at CEA/Saclay. 相似文献
2.
We consider the matter effects on neutrinos moving in background on the basis of the corresponding quantum wave equations.
Both Dirac and Majorana neutrino cases are discussed. The effects for Dirac neutrino reflection and trapping as well as neutrino—antineutrino
annihilation and ν
pair creation in matter at the interface between two media with different densities are considered. The spin light of neutrinos
in matter is also discussed.
The text was submitted by the authors in English. 相似文献
3.
Using the self-consistent pseudopotential method, we have calculated the binding energy of the image states for the (0001)
, and
surfaces of beryllium. It is shown for the (0001) face that there exists a pronounced resonance image state with n=1 and energy −0.95 eV at the point
of the surface Brillouin zone. In the
surface, which has a wide band gap in the vicinity of the vacuum level, the calculated image state with n=1 at the point
has energy −1.2 eV and is a surface state of gap type. For the
face in the vicinity of the point
band gaps are absent. However, the symmetry of the bulk states near the vacuum level enables the existence of a resonance
image state with n=1 and energy −0.6 eV.
Fiz. Tverd. Tela (St. Petersburg) 41, 935–940 (June 1999) 相似文献
4.
The process of baryon production in Kp collisions at high energies is considered in the framework of the quark-gluon string model. The contribution of the string-junction
mechanism to the strange-baryon production is analyzed. The results of numerical calculations are in reasonable agreement
with the data on inclusive spectra of p, Λ,
and on the
/Λ asymmetry. The predictions for inclusive spectra and production asymmetry of Ξ and Ω baryons are presented.
The text was submitted by the authors in English. 相似文献
5.
6.
N. M. Agababyan V. V. Ammosov M. Atayan N. Grigoryan H. Gulkanyan A. A. Ivanilov Zh. Karamyan V. A. Korotkov 《Physics of Atomic Nuclei》2006,69(1):35-38
The influence of nuclear effects on the production of neutral strange particles (V
0) is investigated using the data obtained with SKAT propane-freon bubble chamber irradiated in the neutrino beam (with E
v
=3−30 GeV) at the Serpukhov accelerator. The mean multiplicity of V
0 particles in nuclear interactions,
, is found to exceed significantly that in “quasideuteron” interactions,
. The ratio of
is larger than that for π− mesons,
. It is shown that the multiplicity gain of V
0 particles can be explained by intranuclear interactions of produced pions.
The text was submitted by the authors in English. 相似文献
7.
8.
A. N. Ivanov H. Oberhummer N. I. Troitskaya M. Faber 《The European Physical Journal A - Hadrons and Nuclei》2000,8(2):223-250
A dynamics of low-energy nuclear forces is investigated for low-energy electromagnetic and weak nuclear reactions with the
deuteron in the Nambu-Jona-Lasinio model of light nuclei by example of the neutron-proton radiative capture (M1-capture) n
+ p → D + γ, the photomagnetic disintegration of the deuteron γ + D → n + p and weak reactions of astrophysical interest. These are the solar proton burning p + p → D + e+ + ν
e, the pep-process p + e− + p → D + ν
e and the neutrino and antineutrino disintegration of the deuteron caused by charged ν
e + D → e− + p + p, + D → e+ + n + n and neutral ν
e() + D → ν
e() + n + p weak currents. 相似文献
9.
N. I. Rukhadze P. Beneš Ch. Briançon V. B. Brudanin P. Čermák F. A. Danevich V. G. Egorov K. N. Gusev A. A. Klimenko V. E. Kovalenko A. Kovalik A. V. Salamatin I. Štekl V. V. Timkin V. I. Tretyak Ts. Vylov 《Physics of Atomic Nuclei》2006,69(12):2117-2123
A search for double electron capture of 106Cd was performed at the Modane Underground Laboratory (4800 m w.e.) using a low-background and high-sensitivity multidetector
spectrometer TGV-2 (Telescope Germanium Vertical). New limits on β
+/EC, EC/EC decays of 106Cd were obtained from preliminary calculations of experimental data accumulated for 4800 h of measurement of 10 g of 106Cd with enrichment of 75%. They are
> 9.1 × 1018 yr,
> 1.9 × 1019 yr for transitions to the first 2+, 511.9 keV excited state of 106Pd, and
> 1.3 × 1019 yr,
> 6.2 × 1019 yr for transitions to the ground 0+ state of 106Pd. All limits are given at 90% C.L.
The text was submitted by the authors in English. 相似文献
10.
Yu. M. Andreev S. I. Bityukov N. V. Krasnikov A. N. Toropin 《Physics of Atomic Nuclei》2007,70(10):1717-1724
The LHC (CMS) discovery potential in the search for supersymmetry and lepton-flavor violation in neutralino decays using the
e
± μ∓ + E
T
miss
signature is studied. A detailed study is done for the CMS test points LM1-LM9. It is shown that, for the point LM1, it is
possible to detect lepton-flavor violation in neutralino decays with lepton-flavor-violating branching Br(
→ μ±
e
∓
) ≥ 0.04 Br(
→ e
+
e
−
, μ+ μ−
) for an integral luminosity of 10 fb−1. The discovery potential in the mSUGRA-SUSY scenario with tan β = 10, sgn(μ) = + in the (m
0, m
1/2) plane using the e
± μ∓ + E
T
miss
signature is determined.
The text was submitted by the authors in English. 相似文献
11.
V. A. Kovalchuk 《Physics of Atomic Nuclei》2007,70(4):722-731
A method for determining the angle γ and the ratio of the amplitudes A
λ(B
− →
K
*−) and A
λ)B
− → D
*0
K
*−), r
Bλ, for all three vector-meson polarization states by using the decays B
∓ → D
*
K
*∓ is proposed. This method relies on the interference between the decays B
− → D
*0
K
*− and B
− →
K
*−, which arises if D
*0 and
decay to D
0/
π
0 and D
0/
γ, whereupon D
0 and
mesons decay to common final hadron states. The doubly Cabibbo-suppressed modes of D
0-meson decay are chosen here to specify such final states.
Original Russian Text ? V.A. Kovalchuk, 2007, published in Yadernaya Fizika, 2007, Vol. 70, No. 4, pp. 754–763. 相似文献
12.
G. Lévai 《Czechoslovak Journal of Physics》2006,56(9):953-966
The Scarf I and Scarf II potentials are discussed within a common mathematical framework, which is then specified to handle
the two potentials separately both in the conventional Hermitian and in the
-symmetric setting. The physically admissible solutions are identified in each case together with the corresponding energy
eigenvalues. Several main differences between the
-symmetric Scarf I and II potentials are pointed out. These include the presence and absence of the quasi-parity quantum number,
the sign of the pseudo-norm, the mechanism of the spontaneous breakdown of
symmetry and the non-
orthogonality of otherwise admissible solutions in the Scarf I potential. Similarities and differences with respect to the
corresponding Hermitian systems are also pointed out. 相似文献
13.
We discuss the behavior of magnetically trapped antihydrogen (
) at temperatures relevant for gravity and spectroscopy experiments (well below 1 K) and the possibilities of attaining these
temperatures. Two possible options are considered. In the discussion of the first one, i.e.
as admixture in cold H gas, we develop the quantum-mechanical theory of
-H (and also
-H) elastic and rearrangement collisions at ultra-low (sub-Kelvin) energies, when s-wave scattering in the incoming channel
dominates. The rate constant of rearrangement leading to
decay turns out to be large, which makes the possibilities for
collisional cooling in H gas and
-H coexistence rather limited. As we show, the most promising is the other option, i.e.
atoms in the collisionless regime. For this regime the possibility of one-dimensional adiabatic cooling of
is demonstrated by using the example of the Ioffe trap. This phenomenon, interesting from the fundamental point of view,
offers the opportunity to cool
below 1 mK. 相似文献
14.
G.L. Borchert D. Anagnostopoulos M. Augsburger D. Belmiloud C. Castelli D. Chatellard M. Daum J.P. Egger P. El-Khoury M. Elble R. Frosch H. Gorke D. Gotta P. Hauser P. Indelicato K. Kirch S. Lenz N. Nelms K. Rashid O.W.B. Schult Th. Siems L.M. Simons 《Hyperfine Interactions》1998,114(1-4):157-164
Some time after its formation an exotic atom may be considered a hydrogen-like system consisting of a nucleus and an exotic
particle in a bound state. In this situation it is an ideal tool to study cascade properties, while for the innermost orbits
it can be used to probe the interaction with the nucleus. From an extended series of experiments using high resolution X-ray
spectroscopy for both aspects typical examples are reported and preliminary results are given: 1. To determine the complex
scattering length in
H the
hyperfine transitions have been measured. 2. To determine the pion mass the 5
4 transitions in
N have been studied. In all cases a major contribution to the uncertainty originates from the calibration. Therefore a new
method is proposed that will establish a universal set of high precision calibration lines for pionic, muonic and electronic
systems.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
D. V. Ahluwalia-Khalilova 《General Relativity and Gravitation》2004,36(12):2581-2587
This essay presents a new asymmetry that arises from the interplay of charge conjugation and Lense-Thirring effect. When applied to Majorana neutrinos, the effect predicts
oscillations in gravitational environments with rotating sources. Parameters associated with astrophysical environments indicate that the presented effect is presently unobservable for solar neutrinos. But, it will play an important role in supernovae explosions, and carries relevance for the observed matter-antimatter asymmetry in the universe. 相似文献
16.
G.Ya. Korenman 《Hyperfine Interactions》1999,119(1-4):227-233
Effect of medium density on shift and broadening of (
) spectral lines is considered in the framework of binary-collision approximation with an effective (
)–He potential including the long-range attraction and short-range repulsion. Quantum calculations of the scattering phase
shifts at reasonable values of the potential parameters allow to explain the main features of the observed density effect
on the shape of (
) spectral lines in low-temperature helium.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
Let
be the Haag--Kastler net generated by the
(2) chiral current algebra at level 1. We classify the SL(2,
)-covariant subsystems
by showing that they are all fixed points nets
H
for some subgroup H of the gauge automorphisms group SO(3) of
. Then, using the fact that the net
1 generated by the
(1) chiral current can be regarded as a subsystem of
, we classify the subsystems of
1. In this case, there are two distinct proper subsystems: the one generated by the energy-momentum tensor and the gauge invariant subsystem
. 相似文献
18.
The product of two real spectral triples
and
, the first of which is necessarily even, was defined by A.Connes as
given by
and, in the even-even case, by
. Generically it is assumed that the real structure
obeys the relations
,
,
, where the
-sign table depends on the dimension n modulo 8 of the spectral triple. If both spectral triples obey Connes'
>-sign table, it is seen that their product, defined in the straightforward way above, does not necessarily obey this
-sign table. In this Letter, we propose an alternative definition of the product real structure such that the
-sign table is also satisfied by the product. 相似文献
19.
The difference between the quantity
induced by box diagram and the experimentally measured value of ɛ is determined and used to obtain the value of ∈ with high precision. Present-day knowledge of CKM matrix elements (including
B-factory data) allows us to obtain from the SM expression for
the value of parameter B
K
: B
K
=0.89±0.16. It turns out to be very close to the result of vacuum insertion, B
K
=1.
The text was submitted by the authors in English. 相似文献
20.
Lucy Gow 《Czechoslovak Journal of Physics》2005,55(11):1415-1420
Jonathan Brundan and Alexander Kleshchev recently introduced a new family of presentations for the Yangian Y
of the general linear Lie algebra
. In this article, we extend some of their ideas to consider the Yangian Y
of the Lie superalgebra
. In particular, we give a new proof of the result by Nazarov that the quantum Berezinian is central.
Presented at the International Colloquium “Integrable Systems and Quantum Symmetries”, Prague, 16–18 June 2005. 相似文献