We study the lepton forward-backward asymmetry AFB and the longitudinal K* polarization FL, as well as an observable P2 derived from them, in the rare decays B->K*l+l-, where l+l- is either e+e- or mu+mu-, using the full sample of 471 million BBbar events collected at the Upsilon(4S) resonance with the Babar detector at the PEP-II e+e- collider. We separately fit and report results for the B+->K*+l+l- and B0->K*0l+l- final states, as well as their combination B->K*l+l-, in five disjoint dilepton mass-squared bins. An angular analysis of B+->K*+l+l- decays is presented here for the first time.
$F_L$ angular fit results.
$A_{FB}$ angular fit results.
$P_2$ results with total uncertainties.
The transverse polarization of $\Lambda$ and $\bar\Lambda$ hyperons produced in proton-proton collisions at a center-of-mass energy of 7 TeV is measured. The analysis uses 760 $\mu$b$^{-1}$ of minimum bias data collected by the ATLAS detector at the LHC in the year 2010. The measured transverse polarization averaged over Feynman $x_{\rm F}$ from $5\times 10^{-5}$ to 0.01 and transverse momentum $p_{\rm T}$ from 0.8 to 15 GeV is $-0.010 \pm 0.005({\rm stat}) \pm 0.004({\rm syst})$ for $\Lambda$ and $0.002 \pm 0.006({\rm stat}) \pm 0.004({\rm syst})$ for $\bar\Lambda$. It is also measured as a function of $x_{\rm F}$ and $p_{\rm T}$, but no significant dependence on these variables is observed. Prior to this measurement, the polarization was measured at fixed-target experiments with center-of-mass energies up to about 40 GeV. The ATLAS results are compatible with the extrapolation of a fit from previous measurements to the $x_{\rm F}$ range covered by this mesurement.
Transverse polarization POL of LAMBDA and LAMBDABAR hyperons averaged over PT and XF.
Transverse polarization POL of LAMBDA and LAMBDABAR hyperons as a function of XF.
Transverse polarization POL of LAMBDA and LAMBDABAR hyperons as a function of PT.
We show that Σ+ hyperons produced by 800 GeV/c protons on targets of Be and Cu have significant polarizations (15–20%). These polarizations persist at values of pt≈2 GeV/c and a wide range of xF. The polarizations from the Cu target are consistently less than from Be. The average ratio of the Σ+ polarization from Cu to that from Be is 0.68±0.08.
Measured values of the SIGMA+ polarization as functions of PT and XL for proton CU collisions.
Measured values of the SIGMA+ polarization as functions of PT and XL for proton BE collisions.
We report on measurements of the ϒ(1S), ϒ(2S), and ϒ(3S) differential cross sections (d2σ/dpTdy)|y|<0.4, as well as on the ϒ(1S) polarization in pp¯ collisions at s=1.8TeV using a sample of 77±3pb−1 collected by the collider detector at Fermilab. The three resonances were reconstructed through the decay ϒ→μ+μ−. The measured angular distribution of the muons in the ϒ(1S) rest frame is consistent with unpolarized meson production.
The differential cross section times the branching ratio into mu+ mu- for UPSILON(1S) production.
The differential cross section times the branching ratio into mu+ mu- for UPSILON(2S) production. The first DSYS error is the systematic error due to the polarization of the UPSILON which is shown seperately from the other systematic errors.
The differential cross section times the branching ratio into mu+ mu- for UPSILON(3S) production. The first DSYS error is the systematic error due to the polarization of the UPSILON which is shown seperately from the other systematic errors.
New results of the neutron-proton spin-dependent total cross section difference$\Delta\sigma_L(np)$at the neutron beam kinetic energies 1.59, 1.79 and 2.20 GeV ar
Final results from the np data.
Values of the cross section difference at I=0 deduced by combining these npdata with pure pp (I=1) data from other experiments.
New precise data of the$\Lambda^0$polarization are obtained in the EXCHARM experiment at the Serpukhov accelerator. The$\Lambda^0$
LAMBDA polarization as a function of PT for the whole XL region.
LAMBDA polarization as a function of PT for three XL regions.
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No description provided.
No description provided.
No description provided.
Surprisingly large polarizations in hyperon production by unpolarized protons have been known for a long time. The spin dynamics of the production process can be further investigated with polarized beams. Recently, a negative asymmetry AN was found in inclusive Λ0 production with a 200GeV/c transversely polarized proton beam. The depolarization DNN in p↑+p→Λ0+X has been measured with the same beam over a wide xF range and at moderate pT. DNN reaches positive values of about 30% at high xF and pT∼1.0GeV/c. This result shows a sizable spin transfer from the incident polarized proton to the outgoing Λ0.
Errors are statistical only. The systematic errors are estimated to be negligible.
Errors are statistical only. The systematic errors are estimated to be negligible.
Errors are statistical only. The systematic errors are estimated to be negligible.
We present experimental results on measuring a single spin asymmetry in η-meson production in the interaction of transversely polarized protons and antiprotons at p lab = 200 GeV / c with a proton target in the region 0.2 < x F < 0.7 for p ↑ p , 0.3 < x F < 0.7 for p ̄ ↑p and 0.7 < p T < 2.0 GeV / c . A comparison of single spin asymmetries in π- and η-meson production is made.
The true asymmetry for ETA production in proton-proton collisions.
The true asymmetry for ETA production in antiproton-proton collisions.
The tensor analyzing power T 20 for the p ( d , p d) and p ( d , p ) pn reactions θ cm p = 180° have been measured at incident deuteron momenta from 3.5 to 6.5 GeV/ c . For both reactions T 20 remains negative up to internal momentum k ⋍ 0.85 GeV/ c and show a rich structure beyond the region where T 20 is expected to be determined by the S - and D -states of the deuteron. The T 20 data for deuteron breakup without pion production, close to the backward elastic kinematics, were obtained simultaneously with the elastic data.
K is the internal momentum of the nucleon.
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