55962579
The T2K Experiment
The T2K experiment is a long-baseline neutrino oscillation experiment. Its main goal is to measure the last unknown lepton sector mixing angle {\theta}_{13} by observing {\nu}_e appearance in a {\nu}_{\mu} beam. It also aims to make a precision measurement of the known oscillation parameters, {\Delta}m^{2}_{23} and sin^{2} 2{\theta}_{23}, via {\nu}_{\mu} disappearance studies. Other goals of the experiment include various neutrino cross section measurements and sterile neutrino searches. The experiment uses an intense proton beam generated by the J-PARC accelerator in Tokai, Japan, and is composed of a neutrino beamline, a near detector complex (ND280), and a far detector (Super-Kamiokande) located 295 km away from J-PARC. This paper provides a comprehensive review of the instrumentation aspect of the T2K experiment and a summary of the vital information for each subsystem.
126301914
Study of neutrino and anti-neutrino charged current interactions in U70 wide band beams
119104383
Spin physics with light and heavy neutral mesons at Protvino
PROZA-M experiment results as well the proposal of a new spin program with the use of a polarized proton beam are presented. Significant asymmetries were observed in inclusive $\pi^0$ production. The new program proposes to study a wealth of single- and double-spin observables in various reactions using longitudinally and transversely polarized proton beams at U70. The main goal is to define gluon contribution to nucleon spin by measuring double-spin asymmetry in charmonium production.
56397085
Measurements of the T2K neutrino beam properties using the INGRID on-axis near detector
Precise measurement of neutrino beam direction and intensity was achieved based on a new concept with modularized neutrino detectors. INGRID (Interactive Neutrino GRID) is an on-axis near detector for the T2K long baseline neutrino oscillation experiment. INGRID consists of 16 identical modules arranged in horizontal and vertical arrays around the beam center. The module has a sandwich structure of iron target plates and scintillator trackers. INGRID directly monitors the muon neutrino beam profile center and intensity using the number of observed neutrino events in each module. The neutrino beam direction is measured with accuracy better than 0.4 mrad from the measured profile center. The normalized event rate is measured with 4% precision.
16849815
LED monitoring system for the BTeV lead tungstate crystal calorimeter prototype
We report on the performance of a monitoring system for a prototype calorimeter for the BTeV experiment that uses lead tungstate crystals coupled with photomultiplier tubes. The tests were carried out at the 70-GeV accelerator complex at Protvino, Russia.
124737810
ATLAS: technical proposal for a general-purpose p p experiment at the large hadron collider at CERN
14358326
Oldmetal‐rich globular cluster populations: Peak color and peak metallicity trends with mass of host spheroids
We address the problem of the factors contributing to a peak color trend of old metal-rich globular cluster (MRGC) populations with mass of their hosts, early-type galaxies and spheroidal subsystems of spiral ones (spheroids). The colormass trend is often converted to a metallicity-mass trend under the assumption that age effects are small or negligible. While direct estimates of the ages of MRGC populations neither can rule out nor reliably support the populations' age trend, key data on timing of the formation of spheroids and other indirect evidence imply it in the sense: the more massive spheroid the older on average its MRGC population. We show that the contribution of an allowable age trend of the MRGC populations to their peak color trend can achieve up to ∼50% or so. In this event the comparable value of the color trend, ∼30%, is due to alpha-element ratio systematic variations of the order of Δ[α /Fe] ≈ 0.1 to 0.2 dex because of a correlation between the [α /Fe] ratios and age. Hence a systematic variation of exactly [Fe/H] ratios may turn out to be less significant among the contributors, and its range many times lower, i.e. of the order of Δ[Fe/H]∼0.1 or even none, than the corresponding range deduced by assuming no age trend. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
118584677
Study of Delta and Roper resonances excitation in light nuclei induced reactions
The excitation mechanisms and properties of broad hadronic resonances in nuclei, which are intimately related with nuclear medium response on high energy excitations, have attracted much attention during last decade.
14121256
Metal-rich Globular Clusters: An Unaccounted Factor Responsible for Their Formation?
A presently unaccounted but quite probable “chemical factor” may be responsible for the formation of old metal-rich globular clusters (MRGCs) in spheroids, as well as of their conterparts, young (intermediate–age) massive star clusters (MSCs) in irregulars. Their formation presumably occurs ~ at the same stage of the host galaxies’ chemical evolution and is related to the essentially increased SF activity in the hosts around the same metallicity, ~Z⊙/3 ([Fe/H]~-0.5). It is achieved very soon in massive spheroids, later in lower-mass spheroids, and (much) more later in irregulars.
8089705
Massive Star Cluster Populations in Irregular Galaxies as Probable Younger Counterparts of Old Metal-rich Globular Cluster Populations in Spheroids
Peak metallicities of metal-rich populations of globular clusters (MRGCs) belonging to early-type galaxies and spheroidal subsystems of spiral galaxies (spheroids) of different mass fall within the somewhat conservative -0.7 ? [Fe/H] ? -0.3 range. Indeed, if possible age effects are taken into account, this metallicity range might become smaller. Irregular galaxies such as the Large Magellanic Cloud (LMC), with longer timescales of formation and lower star formation (SF) efficiency, do not contain old MRGCs with [Fe/H] > -1.0, but they are observed to form populations of young/intermediate-age massive star clusters (MSCs) with masses exceeding 104 M?. Their formation is widely believed to be an accidental process fully dependent on external factors. From the analysis of available data on the populations and their hosts, including intermediate-age populous star clusters in the LMC, we find that their most probable mean metallicities fall within -0.7 ? [Fe/H] ? -0.3, as the peak metallicities of MRGCs do, irrespective of signs of interaction. Moreover, both the disk giant metallicity distribution function (MDF) in the LMC and the MDFs for old giants in the halos of massive spheroids exhibit a significant increase toward [Fe/H] ? -0.5. That is in agreement with a correlation found between SF activity in galaxies and their metallicity. The formation of both the old MRGCs in spheroids and MSC populations in irregular galaxies probably occurs at approximately the same stage of the host galaxies' chemical evolution and is related to the essentially increased SF activity in the hosts around the same metallicity that is achieved very early in massive spheroids, later in lower mass spheroids, and much later in irregular galaxies. Changes in the interstellar dust, particularly in elemental abundances in dust grains and in the mass distribution function of the grains, may be among the factors regulating star and MSC formation activity in galaxies. Strong interactions and mergers affecting the MSC formation presumably play an additional role, although they can substantially intensify the internally regulated MSC formation process. Several implications of our suggestions are briefly discussed.
16158852
Age Dating of Globular Clusters Using UBV(RI) Main-sequence Photometry in the Two-color Diagram: Age of NGC 6397
I propose and apply a method for deriving ages of the metal-poor globular clusters (GCs) in a distance-independent way, which is based on age indicator related to the main sequence in the two-color diagrams with U-B index. Age of the metal-poor GC NGC 6397 has been estimated, using Yale isochrones of Demarque et al. (1996), to be close to 16 Gyr provided the cluster metallicity is near [Fe/H]=-2.0.