58945450
Optical measurement of transverse laser cooling with synchro-betatron coupling
Laser cooling experiment of transverse direction for Mg is performed at the small ion storage and cooler ring, S-LSR. We measured horizontal beam size with CCD camera, and longitudinal momentum spread with PAT (Post Acceleration Tube). The measured beam size with CCD camera is decreased from about 1mm to 0.55mm and longitudinal momentum spread measured with PAT increased near the resonant condition. This suggests transverse temperature was transferred to longitudinal direction with synchro-betatron coupling. INTRODUCTION There are several methods to cool ion beam, such as stochastic cooling, electron beam cooling, and laser cooling. Among these methods, laser cooling can achieve the lowest temperature due to its very strong cooling force. The first experiment of laser cooling of ion beam was carried out at TSR [1], and followed at ASTRID [2]. In laser cooling method, a laser is co-propagating or counter-propagating with the ion beam. Since momentum transfer between the laser and the ion beam occurs longitudinally, we can cool the beam particles mainly in the longitudinal direction. Although intra-beam scattering cools the beam transversely, cooling power is weak in usual particle density [3]. Resonant coupling method is proposed to cool ion beam transversely [4]. In the cases betatron tunes (νx, νy) and synchrotron tune νs have the following relations, νs νx = integer νx νy = integer, and there is energy change at a position with a finite dispersion, laser cooling power transmits to transverse direction. In a storage ring, if cooling power is stronger than heating power, beam will be cooled 3-dimensinally. To realize such beam crystallization, the lattice must be properly designed. A small laser-equipped storage ring (SLSR) (Fig. 1) was constructed for this purpose [5]. The principal parameters of S-LSR, the beam and the laser used in the experiment are shown in Table 1.
55043207
DESIGN OF THE NUCLOTRON BOOSTER IN THE NICA PROJECT
NICA is the new complex being constructed on the JINR aimed to provide collider experiments with ions up to uranium at energy of 3.5x3.5 GeV/u. The NICA layout includes Electron String Ion Source, 6.2 Mev/u linac, 600 MeV/u booster synchrotron, upgraded Nuclotron and ion collider with average luminosity of 10 27 cm -2 s -1 . The main goals of the Booster are the following: accumulation of 4·10 9 Au 32+ ions; acceleration of the heavy ions up to energy required for effective stripping; forming of the required beam emittance with electron cooling system. The present layout makes it possible to place the Booster having 211 m circumference and four fold symmetry lattice inside the yoke of the Synchrophasotron (shut down in 2002). The features of this booster, the requirement to the main synchrotron systems and their parameters are presented in this paper.
119320601
The Number of Master Integrals is Finite
For a fixed Feynman graph one can consider Feynman integrals with all possible powers of propagators and try to reduce them, by linear relations, to a finite subset of integrals, the so-called master integrals. Up to now, there are numerous examples of reduction procedures resulting in a finite number of master integrals for various families of Feynman integrals. However, up to now it was just an empirical fact that the reduction procedure results in a finite number of irreducible integrals. It this paper we prove that the number of master integrals is always finite.
1669343
Applying Gröbner bases to solve reduction problems for Feynman integrals
We describe how Grobner bases can be used to solve the reduction problem for Feynman integrals, i.e. to construct an algorithm that provides the possibility to express a Feynman integral of a given family as a linear combination of some master integrals. Our approach is based on a generalized Buchberger algorithm for constructing Grobner-type bases associated with polynomials of shift operators. We illustrate it through various examples of reduction problems for families of one- and two-loop Feynman integrals. We also solve the reduction problem for a family of integrals contributing to the three-loop static quark potential.
18145511
On the reduction of Feynman integrals to master integrals
The reduction of Feynman integrals to master integrals is an algebraic problem that requires algorithmic approaches at the modern level of calculations. Straightforward applications of the classical Buchberger algorithm to construct Grobner bases seem to be inefficient. An essential modification designed especially for this problem has been w orked out. It has been already applied in two- and three-loop calculations. We are also suggesting to combine our method with the Laporta’s algorithm.
15948639
S-bases as a tool to solve reduction problems for Feynman integrals
We suggest a mathematical definition of the notion of master integrals and present a brief review of algorithmic methods to solve reduction problems for Feynman integrals based on integration by parts relations. In particular, we discuss a recently suggested reduction algorithm which uses Grobner bases. New results obtained with its help for a family of three-loop Feynman integrals are outlined.
119222739
Leptonic CP violation phases, quark–lepton similarity and seesaw mechanism
We explore generic features of the leptonic CP violation in the framework of the seesaw type I mechanism with similarity of the Dirac lepton and quarks mass matrices mD. For this, we elaborate on the standard parametrization conditions which allow to simultaneously obtain the Dirac and Majorana phases. If the only origin of CP violation is the left-handed (LH) transformation which diagonalizes mD (similar to quarks), the leptonic CP violation is suppressed and the Dirac phase is close to π or to 0 with sinδCP≈(sinθ13q/sinθ13)cosθ23sinδq∼λ2sinδq. Here λ∼θC, is the Cabibbo mixing angle, and θ13q and θ13 are the 1–3 mixing angles of quarks and leptons respectively. The Majorana phases β1 and β2 are suppressed as λ3sinδq. For Majorana neutrinos implied by seesaw, the right-handed (RH) transformations are important. We explore the simplest extension inspired by Left–Right (L–R) symmetry with small CKM-type CP violation. In this case, seesaw enhancement of the CP violation occurs due to strong hierarchy of the eigenvalues of mD leading to δCP∼1. The enhancement is absent under the phase factorization conditions which require certain relations between parameters of the Majorana mass matrix of RH neutrinos.
119045478
Neutrino Oscillations in Vacuum and Matter
Neutrino oscillations in vacuum have been discussed first by Pontecorvo [1]. Strong transformations of mixed neutrinos in matter [2–4] have three aspects: 
 
1) 
 
The detection of cosmic neutrinos is known to be a unique channel of information about the structure, energetics and evolution of stars as well as galaxies and the Universe. Experimental techniques for their detection are now developed very actively and first results have been obtained. The interpretation of the data should take into account possible effects of resonant neutrino oscillations: neutrinos produced in central regions of stars cross large layers of matter and the properties of neutrino fluxes may be changed drastically. 
 
 
 
 
2) 
 
Changing of neutrino fluxes due to resonant oscillations depend on the difference of mass squared (∆m 2 = m 2 1 − m 2 2) and on neutrino mixing (sin2 2λ) in a quite definite manner. Consequently, the search for effects of resonant oscillations involves measuring ∆m 2 and sin2 2λ. Moreover, the method is sensitive to regions of ∆m 2 vs. sin2 2λ which are far beyond the possibilities of terrestrial experiments. 
 
 
 
 
3) 
 
If effects of resonant oscillations are found (or if ∆m 2 and sin2 2λ are fixed in other experiments), then it will be possible to make definite conclusions about the density profiles which are crossed by neutrinos.
125220940
Vacuum oscillations of solar neutrinos: correlation between spectrum distortion and seasonal variations
Abstract We show that for vacuum oscillation solution of the solar neutrino problem there is a strict correlation between energy spectrum distortion and amplitude of seasonal variations of the solar neutrino flux. The slope parameter which describes distortion of the recoil electron energy spectrum and the seasonal asymmetry of fluxes has been calculated in relevant region of the oscillation parameters. The correlation of the slope and asymmetry gives crucial criteria for identification of this solution.
6112047
SNO: Predictions for ten measurable quantities
We calculate the range of predicted values for 10 quantities that will be measured by the Sudbury Neutrino Observatory ~SNO!. We use neutrino oscillation solutions ~vacuum and MSW; active and sterile neutrinos! that are globally consistent with all available neutrino data and estimate realistic theoretical and experimental uncertainties. The neutral current to charged current double ratio is predicted to be more than 9 s from the no-oscillation solution for all of the currently favored neutrino oscillation solutions. The best-fit oscillation solutions predict a CC day-night rate difference between 20.1% and 112.5% and a NC day-night difference ,0.01%. We present also the predicted range for the first and the second moments of the charged current electron recoil energy spectrum, the charged current, the neutral current, and the n-e scattering rates, the seasonal dependence of the charged current rate, and the double ratio of neutrino-electron scattering rate to charged current rate. What can one learn from measurements with the Sudbury Neutrino Observatory ~SNO !@ 1#? What are the most likely quantitative results for each of the different experiments that can be carried out with SNO? The main goal of this paper is to help answer these questions by providing quantitative predictions for the most important diagnostic tests of neutrino oscillations that can be performed with SNO. SNO is not an experiment. Like the LEP and SuperKamiokande, SNO is a series of experiments. We calculate the currently favored range of predictions for 10 quantities that are affected by neutrino oscillations and which SNO will measure. For the impatient reader, we list here the quantities that are sensitive to neutrino oscillations which we investigate ~definitions are given later in the text!: first and second moments of the recoil energy spectrum, the charged current ~CC!, the neutral current ~NC!, and the neutrino-electron scattering rates, the difference between the day and the night rates for both the CC and the NC, the difference in the winter-summer CC rates, the neutral current ~NC! to charged current ~CC! double ratio, and the neutrino-electron scattering to CC double ratio. The simultaneous analysis of all the SNO results, measured values and upper limits, will be a powerful technique for constraining neutrino oscillation parameters. As an initial step in this direction, we analyze the combined results for five especially informative pairs of oscillation parameters. A. SNO reactions The SNO Collaboration will study charged current ~CC! neutrino absorption by deuterium, n e1d! p1 p1e 2 , ~1!
18492548
Pontecorvo's original oscillations revisited
Abstract We show that a left-handed neutrino ν L can oscillate into its CPT -conjugate state ν R with maximal amplitude, in direct analogy with K 0 − K 0 oscillations. Peculiarities of such oscillations under different conditions are studied.