92980698
Branching fraction and CP asymmetry of the decays $B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+$ and $B^+ \to K_{\rm \scriptscriptstyle S}^0 K^+$
An analysis of B+ → K0 Sπ and B+ → K0 SK decays is performed with the LHCb experiment. The pp collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-of-mass energies of √ s = 7 TeV and √ s = 8 TeV, respectively. The ratio of branching fractions and the direct CP asymmetries are measured to be B(B+ → K0 SK)/B(B → K0 Sπ) = 0.064 ± 0.009 (stat.) ± 0.004 (syst.), ACP (B+ → K0 Sπ) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP (B+ → K0 SK) = −0.21± 0.14 (stat.)± 0.01 (syst.). The data sample taken at √ s = 7 TeV is used to search for B+ c → K0 SK decays and results in the upper limit (fc · B(B+ c → K0 SK))/(fu · B(B+ → K0 Sπ)) < 5.8× 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a b̄ quark into a B + c or a B + meson, respectively. Submitted to Phys. Lett. B c © CERN on behalf of the LHCb collaboration, license CC-BY-3.0. †Authors are listed on the following pages. ar X iv :1 30 8. 12 77 v2 [ he pex ] 1 N ov 2 01 3
122081812
Study of $\eta-\eta^{\prime}$ mixing from measurement of $B^0_{(s)} \rightarrow J/\psi \eta^{(\prime)}$ decay rates
A study of $B^0$~and $B^0_s$ meson decays into $J/\psi\eta$~and $J/\psi\eta^{\prime}$ final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8TeV, collected by the LHCb experiment and corresponding to 3.0fb$^{-1}$ of integrated luminosity. The decay $B^0 \rightarrow J/\psi \eta^{\prime}$ is observed for thefirst time. The following ratios of branching fractions are measured: $$ \frac{\mathcal{B}(B^0 \rightarrow J/\psi \eta^{\prime})}{\mathcal{B}(B^0_s \rightarrow J/\psi \eta^{\prime})} = (2.28\pm0.65\,(stat)\,\pm0.10\,(syst)\,\pm0.13\,(f_{s}/f_{d}))\times10^{-2},$$ $$ \frac{\mathcal{B}(B^0 \rightarrow J/\psi \eta)}{\mathcal{B}(B^0_s \rightarrow J/\psi \eta)} = (1.85\pm0.61\,(stat)\,\pm0.09\,(syst)\,\pm0.11\,(f_{s}/f_{d}))\times10^{-2},$$ where the third uncertainty is related to the present knowledge of $f_{s}/f_{d}$, the ratio between the probabilities for a $b$ quark to form a $B^0_s$ or $B^0$ meson. The branching fraction ratios are used to determine the parameters of $\eta-\eta^{\prime}$ meson mixing. In addition, the first evidence for the decay $B^0_s \rightarrow \psi(2S) \eta^{\prime}$ is reported, and the relative branching fraction is measured, 
$$\frac{\mathcal{B}(B^0_s \rightarrow \psi(2S) \eta^{\prime})}{\mathcal{B}(B^0_s \rightarrow J/\psi \eta^{\prime})} = (38.7\pm9.0\,(stat)\,\pm1.3\,(syst)\,\pm0.9(\mathcal{B}))\times10^{-2},$$ 
where the third uncertainty is due to the limited knowledge of the branching fractions of $J/\psi$ and $\psi(2S)$~mesons.
118038287
Measurement of the Z+b-jet cross-section in pp collisions at s$$ \sqrt{s} $$ = 7 TeV in the forward region
A bstractThe associated production of a Z boson or an off-shell photon γ* with a bottom quark in the forward region is studied using proton-proton collisions at a centre-of-mass energy of 7 TeV. The Z bosons are reconstructed in the Z/γ* → μ+μ− final state from muons with a transverse momentum larger than 20 GeV, while two transverse momentum thresholds are considered for jets (10 GeV and 20 GeV). Both muons and jets are reconstructed in the pseudorapidity range 2.0 < η < 4.5. The results are based on data corresponding to 1.0 fb−1 recorded in 2011 with the LHCb detector. The measurement of the Z+b-jet cross-section is normalized to the Z+jet cross-section. The measured cross-sections are
0.1σZ/γ*μ+μ−+b‐jet=295±60stat±51syst±10lumifb$$ \sigma \left(\ \mathrm{Z}/{\gamma}^{*}\left({\mu}^{+}{\mu}^{-}\right) + \mathrm{b}\hbox{-} \mathrm{jet}\right)=295\pm 60\ \left(\mathrm{stat}\right)\pm 51\ \left(\mathrm{syst}\right)\pm 10\ \left(\mathrm{lumi}\right)\ \mathrm{f}\mathrm{b} $$
for pT(jet) > 10 GeV, and
0.2σZ/γ*μ+μ−+b‐jet=128±36stat±22syst±5lumifb$$ \sigma \left(\mathrm{Z}/{\gamma}^{*}\left({\mu}^{+}{\mu}^{-}\right)+\mathrm{b}\hbox{-} \mathrm{jet}\right)=128\pm 36\ \left(\mathrm{stat}\right)\pm 22\ \left(\mathrm{syst}\right)\pm 5\ \left(\mathrm{lumi}\right)\ \mathrm{f}\mathrm{b} $$
for pT(jet) > 20 GeV.

209834344
Measurement of the CKM angle $\gamma$ using $B^\pm \to D K^\pm$ with $D \to K^0_{\rm S} \pi^+\pi^-, K^0_{\rm S} K^+ K^-$ decays
204937677
Measurement of $C\!P$ asymmetries in the decays $B^0 \rightarrow K^{*0} \mu^+ \mu^-$ and $B^+ \rightarrow K^{+} \mu^+ \mu^-$
The direct $C\!P$ asymmetries of the decays $B^0 \rightarrow K^{*0} \mu^+ \mu^-$ and $B^+ \rightarrow K^{+} \mu^+ \mu^-$ are measured using $pp$ collision data corresponding to an integrated luminosity of 3.0$\mbox{fb}^{-1}$ collected with the LHCb detector. The respective control modes $B^0 \rightarrow J/\psi K^{*0}$ and $B^+ \rightarrow J/\psi K^{+}$ are used to account for detection and production asymmetries. The measurements are made in several intervals of $\mu^+ \mu^-$ invariant mass squared, with the $\phi(1020)$ and charmonium resonance regions excluded. Under the hypothesis of zero $C\!P$ asymmetry in the control modes, the average values of the asymmetries are \begin{align} 
{\cal A}_{C\!P}(B^0 \rightarrow K^{*0} \mu^+ \mu^-) &= -0.035 \pm 0.024 \pm 0.003, \cr 
{\cal A}_{C\!P}(B^+ \rightarrow K^{+} \mu^+ \mu^-) &= \phantom{-}0.012 \pm 0.017 \pm 0.001, \end{align} where the first uncertainties are statistical and the second are due to systematic effects. Both measurements are consistent with the Standard Model prediction of small $C\!P$ asymmetry in these decays.
54960779
Measurement of the resonant and CP components in $\overline{B}^0\to J/\psi \pi^+\pi^-$ decays
The resonant structure of the reaction $\overline{B}^0\rightarrow J/\psi \pi^+\pi^-$ is studied using data from 3 fb$^{-1}$ of integrated luminosity collected by the LHCb experiment, one-third at 7 Tev center-of-mass energy and the remainder at 8 Tev. The invariant mass of the $\pi^+\pi^-$ pair and three decay angular distributions are used to determine the fractions of the resonant and non-resonant components. Six interfering $\pi^+\pi^-$ states: $\rho(770)$, $f_0(500)$, $f_2(1270)$, $\rho(1450)$, $\omega(782)$ and $\rho(1700)$ are required to give a good description of invariant mass spectra and decay angular distributions. The positive and negative CP fractions of each of the resonant final states are determined. The $f_0(980)$ meson is not seen and the upper limit on its presence, compared with the observed $f_0(500)$ rate, is inconsistent with a model of tetraquark substructure for these scalar mesons at the eight standard deviation level. In the $q\overline{q}$ model, the absolute value of the mixing angle between the $f_0(980)$ and the $f_0(500)$ scalar mesons is limited to be less than $17^{\circ}$ at 90% confidence level.
121749820
Response functions for deep inelastic scattering from Ca-40
Deep inelastic electron scattering cross sections have been measured from /sup 40/Ca at energies between 100 and 375 MeV and at scattering angles of 90/sup 0/ and 140/sup 0/. Longitudinal and transverse response functions at three-vector momentum transfers of 330, 370, and 410 MeV/c were extracted from these data using a Rosenbluth separation. The integrated longitudinal response functions for the three momentum transfers are found to have, respectively, 65%, 75%, and 90% of the longitudinal strength predicted by the Fermi gas model.
121021036
G**p(E) / G**p(M) for bound protons: first results for O-16 with the recoil polarization technique
The first (e,e'p) polarization transfer measurements on a nucleus heavier than deuterium have been carried out at Jefferson Laboratory. Transverse and longitudinal components of the polarization of protons ejected in the reaction 16O(e,e'p) were measured in quasielastic perpendicular kinematics at a Q^2 of 0.8 (GeV/c)^2. The data are in good agreement with state of the art calculations, but do not exclude possible changes in the ratio of the electric to magnetic form factors of the nucleon in the nuclear medium at the level of recent theoretical predictions.
117708238
STACKTAIL MOMENTUM COOLING IN THE FERMILAB ANTIPROTON SOURCE
125624734
Quasielastic electron scattering from He 3 and He 4
12485916
Eta photoproduction on the proton for photon energies from 0.75 to 1.95 GeV.
Differential cross sections for gammap-->etap have been measured with tagged real photons for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information for protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W=1.75 GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S11 resonance with mass approximately 1.8 GeV couples to the etaN channel.