Production of K^{+} mesons in charged-current \nu_{\mu} interactions on plastic scintillator (CH) is measured using MINERvA exposed to the low-energy NuMI beam at Fermilab. Timing information is used to isolate a sample of 885 charged-current events containing a stopping K^{+} which decays at rest. The differential cross section in K^{+} kinetic energy, d\sigma/dT_{K}, is observed to be relatively flat between 0 and 500 MeV. Its shape is in good agreement with the prediction by the \textsc{genie} neutrino event generator when final-state interactions are included, however the data rate is lower than the prediction by 15\%.
The predicted $\nu_\mu$ flux per POT for the data included in this analysis.
The differential cross section with respect to $K^+$ kinetic energy $T_{K}$ is given in units of $10^{-39}$ cm$^{2}$ per nucleon per GeV, as well as the total statistical and systematic uncertainties.
The covariance for the flux uncertainty.
The MINERvA collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino-energy range of 5 - 50 GeV. Good agreement is found between the data and predicted ratios, based on charged-lepton nucleus scattering, at medium x and low neutrino energies. However, the data rate appears depleted in the vicinity of the nuclear shadowing region, x < 0.1. This apparent deficit, reflected in the DIS cross-section ratio at high neutrino energy , is consistent with previous MINERvA observations and with the predicted onset of nuclear shadowing with the the axial-vector current in neutrino scattering.
Ratio of the total DIS cross section on C to CH as a function of $E_\nu$.
Statistical error matrix of the ratio of the total DIS cross section on C to CH as a function of $E_\nu$.
Systematic error matrix of the ratio of the total DIS cross section on C to CH as a function of $E_\nu$.
We study the processes $\gamma \gamma \to K^0_S K^{\pm}\pi^{\mp}$ and $\gamma \gamma \to K^+ K^- \pi^0$ using a data sample of 519~$fb^{-1}$ recorded with the BaBar detector operating at the SLAC PEP-II asymmetric-energy $e^+ e^-$ collider at center-of-mass energies at and near the $\Upsilon(nS)$ ($n = 2,3,4$) resonances. We observe $\eta_c$ decays to both final states and perform Dalitz plot analyses using a model-independent partial wave analysis technique. This allows a model-independent measurement of the mass-dependence of the $I=1/2$ $K \pi$ $\mathcal{S}$-wave amplitude and phase. A comparison between the present measurement and those from previous experiments indicates similar behaviour for the phase up to a mass of 1.5 $GeV/c^2$. In contrast, the amplitudes show very marked differences. The data require the presence of a new $a_0(1950)$ resonance with parameters $m=1931 \pm 14 \pm 22 \ MeV/c^2$ and $\Gamma=271 \pm 22 \pm 29 \ MeV$.
Measured amplitude and phase values for the $I=1/2$ $K \pi$ $\mathcal{S}$-wave as functions of mass obtained from the Model Independent Partial Wave Analysis (MIPWA) of $\eta_c \to K^0_{\scriptscriptstyle S} K^{\pm}\pi^{\mp}$. The amplitudes and phases in the mass interval 14 are fixed to constant values.
Measured amplitude and phase values for the $I=1/2$ $K \pi$ $\mathcal{S}$-wave as functions of mass obtained from the Model Independent Partial Wave Analysis (MIPWA) of $\eta_c \to K^+ K^- \pi^0$. The amplitudes and phases in the mass interval 14 are fixed to constant values.
We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ using the decay $B\to D\ell\nu_\ell$ ($\ell=e,\mu$) based on 711 fb$^{-1}$ of $e^+e^-\to \Upsilon(4S)$ data recorded by the Belle detector and containing $772 \times 10^6$ $B\bar{B}$ pairs. One $B$ meson in the event is fully reconstructed in a hadronic decay mode while the other, on the signal side, is partially reconstructed from a charged lepton and either a $D^+$ or $D^0$ meson in a total of 23 hadronic decay modes. The isospin-averaged branching fraction of the decay $B\to D\ell\nu_\ell$ is found to be $\mathcal{B}(B^0 \to D^- \ell^+ \nu_{\ell})=(2.31\pm 0.03(\mathrm{stat})\pm 0.11(\mathrm{syst}))\%$. Analyzing the differential decay rate as a function of the hadronic recoil with the parameterization of Caprini, Lelouch and Neubert and using the form-factor prediction $\mathcal{G}(1)=1.0541\pm 0.0083$ calculated by FNAL/MILC, we obtain $\eta_\mathrm{EW}|V_{cb}|=(40.12\pm 1.34)\times 10^{-3}$, where $\eta_\mathrm{EW}$ is the electroweak correction factor. Alternatively, assuming the model-independent form-factor parameterization of Boyd, Grinstein and Lebed and using lattice QCD data from the FNAL/MILC and HPQCD collaborations, we find $\eta_\mathrm{EW}|V_{cb}|=(41.10 \pm 1.14)\times 10^{-3}$.
The values of $\Delta\Gamma_i/\Delta w$ with the statistical and systematic uncertainties in the ${B^+ \to \bar{D}^0 e^+ \nu_{e}}, {B^+ \to \bar{D}^0 \mu^+ \nu_{\mu}}, {B^0 \to D^- e^+ \nu_{e}},$ and ${B^0 \to D^- \mu^+ \nu_{\mu}}$ sub-samples. The recoil variable, $w$, is defined as the product of the 4-velocities of the $B$ and $D$ mesons. The value of $w_\rm{max}$ is 1.59209 for the sub-samples with a charged $B$ meson and 1.58901 for the sub-samples with a neutral $B$ meson. The $\Delta\Gamma_i/\Delta w$ results are statistically uncorrelated amongst bins and samples. The systematic correlations between bins and samples are given in the file SubsampleResults.csv of the arXiv source.
The values of $\Delta\Gamma_i/\Delta w$ obtained in different bins of $w$ after combination of the ${B^+ \to \bar{D}^0 e^+ \nu_{e}}, {B^+ \to \bar{D}^0 \mu^+ \nu_{\mu}}, {B^0 \to D^- e^+ \nu_{e}},$ and ${B^0 \to D^- \mu^+ \nu_{\mu}}$ sub-samples. The value of $w_\rm{max} = 1.59055$ is the average of the values for charged and neutral $B$ mesons.
The correlation matrix of the systematic error. The value of $w_\rm{max} = 1.59055$ is the average of the values for charged and neutral $B$ mesons.
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.
We report a measurement of the differential cross section of $\pi^0$ pair production in single-tag two-photon collisions, $\gamma^* \gamma \to \pi^0 \pi^0$, in $e^+ e^-$ scattering. The cross section is measured for $Q^2$ up to 30 GeV$^2$, where $Q^2$ is the negative of the invariant mass squared of the tagged photon, in the kinematic range 0.5 GeV < W < 2.1 GeV and $|\cos \theta^*|$ < 1.0 for the total energy and pion scattering angle, respectively, in the $\gamma^* \gamma$ center-of-mass system. The results are based on a data sample of 759 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. The transition form factor of the $f_0(980)$ and that of the $f_2(1270)$ with the helicity-0, -1, and -2 components separately are measured for the first time and are compared with theoretical calculations.
$W$ dependence of the differential cross section ${\rm d}\sigma/{\rm d}|\cos\theta^*|$ in five $|\cos\theta^*|$ bins for $Q^2$=3.45 GeV$^2$.
$W$ dependence of the differential cross section ${\rm d}\sigma/{\rm d}|\cos\theta^*|$ in five $|\cos\theta^*|$ bins for $Q^2$=4.46 GeV$^2$.
$W$ dependence of the differential cross section ${\rm d}\sigma/{\rm d}|\cos\theta^*|$ in five $|\cos\theta^*|$ bins for $Q^2$=5.47 GeV$^2$.
Using data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we measure the energy dependence of the $e^+e^- \to h_b(nP)\pi^+\pi^-$ $(n=1,2)$ cross sections from thresholds up to $11.02\,$GeV. We find clear $\Upsilon(10860)$ and $\Upsilon(11020)$ peaks with little or no continuum contribution. We study the resonant substructure of the $\Upsilon(11020) \to h_b(nP)\pi^+\pi^-$ transitions and find evidence that they proceed entirely via the intermediate isovector states $Z_b(10610)$ and $Z_b(10650)$. The relative fraction of these states is loosely constrained by the current data: the hypothesis that only $Z_b(10610)$ is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only $Z_b(10650)$ is produced is not excluded at a significant level.
Center-of-mass energies, integrated luminosities and Born cross sections for all energy points. The first uncertainty in the energy is uncorrelated, the second is correlated. The three uncertainties in the cross sections are statistical, uncorrelated systematic and correlated systematic.
The $e^+e^-\to K^+K^-$ cross section and charged-kaon electromagnetic form factor are measured in the $e^+e^-$ center-of-mass energy range ($E$) from 2.6 to 8.0 GeV using the initial-state radiation technique with an undetected photon. The study is performed using 469 fb$^{-1}$ of data collected with the BABAR detector at the PEP-II $e^+e^-$ collider at center-of-mass energies near 10.6 GeV. The form factor is found to decrease with energy faster than $1/E^2$, and approaches the asymptotic QCD prediction. Production of the $K^+K^-$ final state through the $J/\psi$ and $\psi(2S)$ intermediate states is observed. The results for the kaon form factor are used together with data from other experiments to perform a model-independent determination of the relative phases between single-photon and strong amplitudes in $J/\psi$ and $\psi(2S)\to K^+K^-$ decays. The values of the branching fractions measured in the reaction $e^+e^- \to K^+K^-$ are shifted relative to their true values due to interference between resonant and nonresonant amplitudes. The values of these shifts are determined to be about $\pm5\%$ for the $J/\psi$ meson and $\pm15\%$ for the $\psi(2S)$ meson.
The $K^+K^-$ invariant-mass interval ($M_{K^+K^-}$), number of selected events ($N_{\rm sig}$) after background subtraction, detection efficiency ($\varepsilon$), ISR luminosity ($L$), measured $e^+e^-\to K^+K^-$ cross section ($\sigma_{K^+K^-}$), and the charged-kaon form factor ($|F_K|$). For the number of events and cross section. For the form factor, we quote the combined uncertainty. For the mass interval 7.5 - 8.0 GeV/$c^2$, the 90$\%$ CL upper limits for the cross section and form factor are listed.
We present measurements of Collins asymmetries in the inclusive process $e^+e^- \rightarrow h_1 h_2 X$, $h_1h_2=KK,\, K\pi,\, \pi\pi$, at the center-of-mass energy of 10.6 GeV, using a data sample of 468 fb$^{-1}$ collected by the BaBar experiment at the PEP-II $B$ factory at SLAC National Accelerator Center. Considering hadrons in opposite thrust hemispheres of hadronic events, we observe clear azimuthal asymmetries in the ratio of unlike- to like-sign, and unlike- to all charged $h_1 h_2$ pairs, which increase with hadron energies. The $K\pi$ asymmetries are similar to those measured for the $\pi\pi$ pairs, whereas those measured for high-energy $KK$ pairs are, in general, larger.
Light quark ($uds$) Collins asymmetries obtained by fitting the U/L and U/C double ratios as a function of ($z_1$,$z_2$) for kaon pairs. In the first column, the $z$ bins and their respective mean values for the kaon in one hemisphere are reported; in the following column, the same variables for the second kaon are shown; in the third column the mean value of $\sin^2\theta_{th}/(1+\cos^2\theta_{th})$ is summarized, calculated in the RF12 frame; in the last two columns the asymmetry results are summarized. The mean values of the quantities reported in the table are calculated by summing the corresponding values for each $KK$ pair and dividing by the number of $KK$ pairs that fall into each ($z_1$,$z_2$) interval. Note that the $A^{UL}$ and $A^{UC}$ results are strongly correlated since they are obtained by using the same data set.
Light quark ($uds$) Collins asymmetries obtained by fitting the U/L and U/C double ratios as a function of ($z_1$,$z_2$) for kaon pairs. In the first column, the $z$ bins and their respective mean values for the kaon in one hemisphere are reported; in the following column, the same variables for the second kaon are shown; in the third column the mean value of $\sin^2\theta_{2}/(1+\cos^2\theta_{2})$ is summarized, calculated in the RF0 frame; in the last two columns the asymmetry results are summarized. The mean values of the quantities reported in the table are calculated by summing the corresponding values for each $KK$ pair and dividing by the number of $KK$ pairs that fall into each ($z_1$,$z_2$) interval. Note that the $A^{UL}$ and $A^{UC}$ results are strongly correlated since they are obtained by using the same data set.
Light quark ($uds$) Collins asymmetries obtained by fitting the U/L and U/C double ratios as a function of ($z_1$,$z_2$) for $K\pi$ hadron pairs. In the first column, the $z$ bins and their respective mean values for the hadron ($K$ or $\pi$) in one hemisphere are reported; in the following column, the same variables for the second hadron ($K$ or $\pi$) are shown; in the third column the mean value of $\sin^2\theta_{th}/(1+\cos^2\theta_{th})$ is summarized, calculated in the RF12 frame; in the last two columns the asymmetry results are summarized. The mean values of the quantities reported in the table are calculated by summing the corresponding values for each $K\pi$ pair and dividing by the number of $K\pi$ pairs that fall into each ($z_1$,$z_2$) interval. Note that the $A^{UL}$ and $A^{UC}$ results are strongly correlated since they are obtained by using the same data set.
The process $e^+e^- \to \gamma\chi_{cJ}$ ($J$=1, 2) is studied via initial state radiation using 980 fb$^{-1}$ of data at and around the $\Upsilon(nS)$ ($n$=1, 2, 3, 4, 5) resonances collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. No significant signal is observed except from $\psi(2S)$ decays. Upper limits on the cross sections between $\sqrt{s}=3.80$ and $5.56~{\rm GeV}$ are determined at the 90% credibility level, which range from few pb to a few tens of pb. We also set upper limits on the decay rate of the vector charmonium [$\psi(4040$), $\psi(4160)$, and $\psi(4415)$] and charmoniumlike [$Y(4260)$, $Y(4360)$, and $Y(4660)$] states to $\gamma\chi_{cJ}$.
Upper limits on the $e^+e^-\to \gamma\chi_{cJ}$ cross sections.
Upper limits on $\Gamma_{ee} \times \mathcal{B}$ at the 90$\%$ C.L.
Upper limits on branching fractions $\mathcal{B}(R \to \gamma \chi_{cJ})$ at the 90$\%$ C.L.
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