119253430
Beam-energy and system-size dependence of dynamical net charge fluctuations
We present measurements of net charge fluctuations in Au+Au collisions at s(NN)=19.6, 62.4, 130, and 200 GeV, Cu+Cu collisions at s(NN)=62.4 and 200 GeV, and p+p collisions at s=200 GeV using the dynamical net charge fluctuations measure nu(+-,dyn). We observe that the dynamical fluctuations are nonzero at all energies and exhibit a modest dependence on beam energy. A weak system size dependence is also observed. We examine the collision centrality dependence of the net charge fluctuations and find that dynamical net charge fluctuations violate 1/N(ch) scaling but display approximate 1/N(part) scaling. We also study the azimuthal and rapidity dependence of the net charge correlation strength and observe strong dependence on the azimuthal angular range and pseudorapidity widths integrated to measure the correlation.
124737810
ATLAS: technical proposal for a general-purpose p p experiment at the large hadron collider at CERN
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.
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.
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.
55042306
First muon-neutrino disappearance study with an off-axis beam
We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment. With data corresponding to 1.43 x 10(20) protons on target, we observe 31 fully-contained single mu-like ring events in Super-Kamiokande, compared with an expectation of 104 +/- 14 (syst) events without neutrino oscillations. The best-fit point for two-flavor nu(mu) -> nu(tau) oscillations is sin(2)(2 theta(23)) = 0.98 and vertical bar Delta m(32)(2)vertical bar = 2.65 x 10(-3) eV(2). The boundary of the 90% confidence region includes the points sin(2)(2 theta(23)), vertical bar Delta m(32)(2)vertical bar = (1.0, 3.1 x 10(-3) eV(2)), (0.84, 2.65 x 10(-3) eV(2)) and (1.0, 2.2 x 10(-3) eV(2)).
14245549
Second-Parameter Globular Clusters in the Milky Way and in M33 as Tracers of Mass Loss from M31 in the Early Epoch?
I suggest that the bulk of the "young", second-parameter globular clusters (SPGCs) observed in the outer halo of our Galaxy and recently found in other massive spiral of the Local Group (LG), M33, may have originated due to mass outflow from M31 and subsequent accretion of gas on the Galaxy and M33 in the early epoch.
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.
16607125
Second parameter globulars and dwarf spheroidals around the Local Group massive galaxies: What can they evidence?
We suggest that the majority of the "young", so-called "second parameter" globular clusters (SPGCs) have origi- nated in the outer Galactic halo due to a process other than a tidal disruption of the dwarf spheroidal (dSph) galaxies. Basic observational evidence regarding both the dSphs and the SPGCs, coupled with the latest data about a rather large relative num- ber of such clusters among globulars in M 33 and their low portion in M 31, seems to be consistent with the suspected process. It might have taken place within the system of the most massive galaxies of the Local Group (LG) at the earliest stages of their formation and evolution. We argue that the origin and basic characteristics of the SPGCs can naturally be explained as a result of mass outflow from M 31, during and due to formation of its Pop. II stars, and subsequent accretion of gas onto its massive companions, the Galaxy and M 33. An amount of the gas accreted onto the Milky Way is expected to have been quite enough for the formation in the outer Galactic halo not only of the clusters under consideration but also a number of those dSph galaxies which are as young as the SPGCs. A less significant, but notable mass transfer from the starbursting protoGalaxy to the massive members of the LG might have occurred, too.
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.
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)