Using two novel methods, pair invariant mass (minv) and comparative measurements with respect to reaction plane (ΨRP) and participant plane (ΨPP), we isolate the possible chiral magnetic effect (CME) ...from backgrounds in 200 GeV Au+Au collisions at STAR. The invariant mass method identifies the resonance background contributions, coupled with the elliptic flow (ν2), to the charge correlator CME observable (Δγ). At high mass (minv>1.5GeV/c2) where resonance contribution is small, we obtain the average Δγ magnitude. In the low mass region (minv<1.5GeV/c2), resonance peaks are observed in Δγ(minv). An event shape engineering (ESE) method is used to model the background shape in minv to extract the potential CME signal at low minv. In the comparative method, the ΨRP is assessed by spectator neutrons measured by the ZDCs, and the ΨPP by the 2nd-harmonic event plane measured by the TPC. The ν2 is stronger along ΨPP and weaker along ΨRP; in contrast, the magnetic field, mainly from spectator protons, is weaker along ΨPP and stronger along ΨRP. As a result, the Δγ measured with respect to ΨRP and ΨPP contain different amounts of CME and background, and can thus determine these two contributions. It is found that the possible CME signals with background isolation by these two novel methods are small, on the order of a few percent of the inclusive Δγ measurements.
We measure the charge asymmetry A ≡ (N++ - N--)/(N++ + N--) of like-sign dimuon events in 6.1 fb-1 of pp collisions recorded with the D0 detector at a center-of-mass energy square root(s) = 1.96 ...TeV at the Fermilab Tevatron collider. From A we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A(sl)(b) = -0.009 57 ± 0.002 51(stat) ± 0.001 46(sys). It differs by 3.2 standard deviations from the standard model prediction A(sl)(b)(SM) = (-2.3(-0.6)(+0.5)) × 10(-4), and provides first evidence of anomalous CP violation in the mixing of neutral B mesons.
The elastic scattering of
6He on
208Pb has been measured at laboratory energies of 14, 16, 18 and 22 MeV. These data were analyzed using phenomenological Woods–Saxon form factors and optical model ...calculations. A semiclassical polarization potential was used to study the effect of the Coulomb dipole polarizability. Evidence for long range absorption, partially arising from Coulomb dipole polarizability, is reported. The energy variation of the optical potential was found to be consistent with the dispersion relations which connect the real and imaginary parts of the potential.
Using the Main Stellar Spectrograph of the 6-m Special Astrophysical Observatory telescope equipped with a polametric analyzer, we measured the longitudinal magnetic field component B^sub ^ for the T ...Tauri stars T Tau and AS 507 on January 16 and 18 and February 15, 2003. For both stars, we determined only the upper limits on B^sub ^ from photospheric lines: +15±30 G for T Tau and -70±90 G for AS 507. The magnetic field of AS 507 was not measured previously, while B^sub ^ for T Tau is lower than its values that we obtained in 1996 and 2002 (B^sub ^150±50G), suggesting that the longitudinal magnetic field component in the photosphere of T Tau is variable. We also measured the longitudinal magnetic field component for T Tau in the formation region of the He I 5876 Å emission line. We found B^sub ^ in this region to be +650, +350, and +1100 G on January 16, 18, and February 15, 2003, respectively. Our observations on January 18 and February 15 correspond to virtually the same phase of the star's rotation period, but the profiles of the He I 5876 Å line differ markedly on these two nights. Therefore, we believe that the threefold difference between the B^sub ^ values on these nights does not result from observational errors. We discuss the possible causes of the B^sub ^ variability in the photosphere and the magnetosphere of T Tau.PUBLICATION ABSTRACT
The spectroscopic constants (vibrational, rotational, and centrifugal) and the radiative parameters (Einstein coefficients for spontaneous emission, oscillator strengths for absorption, Franck–Condon ...factors, R{sub v'v'} centroids, and wavenumbers of rotational lines) of rovibronic transitions in the systems of bands B{sup 1}Π–X{sup 1}Σ{sup +} (0 ≤v'≤ 25, 0 ≤v'≤ 49, j = 0, 30, 50, 60, 70) of the LiCs molecule, as well as the radiative lifetimes of the excited electronic state, are calculated. Calculations are performed based on semiempirical potential curves constructed in this work. The calculated spectroscopic constants are compared with experimental values. The radiative lifetimes are calculated for the first time.
We report on the first measurement of charm-strange meson $D_s^{\pm}$ production at midrapidity in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$ = 200 GeV from the STAR experiment. The yield ratio ...between strange ($D_{s}^{\pm}$) and non-strange ($D^{0}$) open-charm mesons is presented and compared to model calculations. A significant enhancement, relative to a PYTHIA simulation of $p$+$p$ collisions, is observed in the $D_{s}^{\pm}/D^0$ yield ratio in Au+Au collisions over a large range of collision centralities. Model calculations incorporating abundant strange-quark production in the quark-gluon plasma (QGP) and coalescence hadronization qualitatively reproduce the data. The transverse-momentum integrated yield ratio of $D_{s}^{\pm}/D^0$ at midrapidity is consistent with a prediction from a statistical hadronization model with the parameters constrained by the yields of light and strange hadrons measured at the same collision energy. These results suggest that the coalescence of charm quarks with strange quarks in the QGP plays an important role in $D_{s}^{\pm}$ meson production in heavy-ion collisions.
The spectroscopic constants (vibrational, rotational, and centrifugal) and the radiative parameters (Einstein coefficients for spontaneous emission, oscillator strengths for absorption, Franck–Condon ...factors,
R
v
'
v
"
centroids, and wavenumbers of rotational lines) of rovibronic transitions in the systems of bands
B
1
Π–
X
1
Σ
+
(0 ≤
v
'≤ 25, 0 ≤
v
"≤ 49,
j
= 0, 30, 50, 60, 70) of the LiCs molecule, as well as the radiative lifetimes of the excited electronic state, are calculated. Calculations are performed based on semiempirical potential curves constructed in this work. The calculated spectroscopic constants are compared with experimental values. The radiative lifetimes are calculated for the first time.
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