10.15161/oar.it/1448997277.76

A proposal for the phase-1 of the AMADEUS experiment at DAFNE is presented. It contains the physics goals, the setup design, the Monte Carlo simulations and the luminosity requests; a roll-in proposal is also put forward.

JINST

The HARP Collaboration recently published calibrations of their TPC and RPC detectors, and differential cross-sections of large-angle pion production in proton-nucleus collisions. We argue that these calibrations are biased and cross-sections based on them should not be trusted.

Phys. Rev. D

We present a measurement of the correlated $b\bar{b}$ production cross section. The data used in this analysis were taken with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider, and correspond to an integrated luminosity of 742 pb$^{-1}$. We utilize muon pairs with invariant mass $5 \leq m_{\mu\mu} \leq 80 \gevcc$ produced by $b\bar{b}$ double semileptonic decays. For muons with $p_T \geq 3 \gevc$ and $|\eta| \leq 0.7$, that are produced by $b$ and $\bar{b}$ quarks with $p_T \geq 2 \gevc$ and $|y| \leq 1.3$, we measure $\sigma_{b\to\mu,\bar{b}\to \mu}= 1549 \pm 133$ pb. We compare this result with theoretical predictions and previous measurements. We also report the measurement of $\sigma_{c\to\mu,\bar{c}\to \mu}$, a by-product of the study of the background to $b\bar{b}$ production.

Phys. Rev. Lett.

We present the first measurement of the production cross section of a W boson with a single charm quark (c) in p-pbar collisions at sqrt(s)=1.96 TeV, using soft muon tagging of c jets. In a data sample of ~1.8 fb-1, recorded with the CDF II detector at the Fermilab Tevatron, we select events with W+1 or 2 jets. We use the charge correlation between the W and the muon from the semileptonic decay of a charm hadron to extract the Wc signal. We measure sigma_{Wc}(p_{Tc}>20 GeV/c, |\eta_c|<1.5)\times BR(W->\ell\nu) = 9.8+/-3.2 pb, in agreement with theoretical expectations.

Phys. Rev. D

We present a search for the associated production of charginos and neutralinos in p-pbar collisions at 1.96 TeV. The data were collected at the Collider Detector at Fermilab (CDF II) and correspond to integrated luminosities between 0.7 and 1.0 fb-1. We look for final states with one high pT electron or muon, and two additional leptons. Our results are consistent with the standard model expectations, and we set limits on the cross section as a function of the chargino mass in three different supersymmetric scenarios. For a specific MSSM scenario with no slepton mixing we set a 95 % C.L. limit at 151 GeV/c^2.

Phys. Rev. Lett.

Inclusive jet cross sections in Z/gamma^* events, with Z/gamma^* decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in ppbar collisions at sqrt{s} = 1.96 TeV with the upgraded Collider Detector at Fermilab in Run II, based on an integrated luminosity of 1.7 fb^-1. The measurements cover the rapidity region | yjet | < 2.1 and the transverse momentum range ptjet > 30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.

Phys. Atom. Nucl.

The final state interaction of pions in $K_{e4}$ decay allows one to obtain the value of the isospin and angular momentum zero $\pi\pi$ scattering length $a_0^0$.We take into account the electromagnetic interaction of pions and isospin symmetry breaking effects caused by different masses of neutral and charged pions and estimate the impact of these effects on the procedure of scattering length extraction from $K_{e4}$ decay.

Phys.Rev.D

We present a measurement of the cross section for W-boson production in association with jets in pbarp collisions at sqrt(s)=1.96$ TeV. The analysis uses a data sample corresponding to an integrated luminosity of 320 pb^-1 collected with the CDF II detector. W bosons are identified in their electron decay channel and jets are reconstructed using a cone algorithm. For each W+>= n-jet sample ($n= 1 - 4$) we measure sigma(ppbar =>W+>=n$-jet)x BR(W => e nu) with respect to the transverse energy E_T of the n^th-highest E_T jet above 20 GeV, for a restricted W => e nu decay phase space. The cross sections, corrected for all detector effects, can be directly compared to particle level W+ jet(s) predictions. We present here comparisons to leading order and next-to-leading order predictions.

Phys. Lett. B

We present a measurement of the muon neutrino–nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5⩽Eν⩽40 GeV . The significance of this measurement is its precision, ±4% in 2.5⩽Eν⩽10 GeV , and ±2.6% in 10⩽Eν⩽40 GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.

Phys. Rev. Lett.

We report the direct observation of the excited L=1 state B_{s2}* in fully reconstructed decays to B+K-. The mass of the B_{s2}* meson is measured to be {5839.6 +- 1.1 (stat.) +- 0.7 (syst.) MeV/c^2, and its production rate relative to the B+ meson is measured to be [1.15 +- 0.23 (stat.) +- 0.13 (syst.)] %.

Phys.Rev.Lett.

We present the first model-independent measurement of the helicity of $W$ bosons produced in top quark decays, based on a 1 fb$^{-1}$ sample of candidate $t\bar{t}$ events in the dilepton and lepton plus jets channels collected by the D0 detector at the Fermilab Tevatron $p\bar{p}$ Collider. We reconstruct the angle $\theta^*$ between the momenta of the down-type fermion and the top quark in the $W$ boson rest frame for each top quark decay. A fit of the resulting \costheta distribution finds that the fraction of longitudinal $W$ bosons $f_0 = 0.425 \pm 0.166 \hbox{(stat.)} \pm 0.102 \hbox{(syst.)}$ and the fraction of right-handed $W$ bosons $f_+ = 0.119 \pm 0.090 \hbox{(stat.)} \pm 0.053 \hbox{(syst.)}$, which is consistent at the 30% C.L. with the standard model.

Phys. Rev. Lett.

We report a search for R-parity violating production and decay of sneutrino particles in the e+mu final state with 1.04+-0.06 fb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider in 2002--2006. Good agreement between the data and the standard model prediction is observed. With no evidence for new physics, we set limits on the R-parity violating couplings $\lambda^{\prime}_{311}$ and $\lambda_{312}$ as a function of sneutrino mass.

Eur.Phys.J.C

Radiative corrections to the neutral current Drell--Yan-like processes are considered. Complete one-loop electroweak corrections are calculated within the SANC system. Theoretical uncertainties are discussed. Numerical results are presented for typical conditions of LHC experiments.

Phys. Rev. Lett.

We present the first detailed measurement of incoherent photoproduction of neutral pions to a discrete state of a residual nucleus. The $^{12}$C$(\gamma,\pi^{0})^{12}$C$^{*}_{4.4MeV}$ reaction has been studied with the Glasgow photon tagger at MAMI employing a new technique which uses the large solid angle Crystal Ball detector both as a $\pi^{0}$ spectrometer and to detect decay photons from the excited residual nucleus. The technique has potential applications to a broad range of future nuclear measurements with the Crystal Ball and similar detector systems elsewhere. The data are sensitive to the propagation of the $\Delta$ in the nuclear medium and will give the first information on matter transition form factors from measurements with an electromagnetic probe. The incoherent cross sections are compared to two theoretical predictions including a $\Delta$-hole model.

JETP Lett.

Inclusive beauty quark production in photon-photon collisions at CERN LEP2 is considered in the framework of the kt-factorization approach. Both direct and resolved photon contributions are taken into account. The unintegrated gluon distributions in a photon are either obtained from the full CCFM evolution equation or from the Kimber-Martin-Ryskin prescription. The predicted beauty cross section reasonably agrees with the recent experimental data taken by the ALEPH collaboration. We argue that theoretical and experimental studies of the azimuthal correlations in heavy quark production at high energies can serve as a crucial probe of the unintegrated gluon densities.

AIP Conf.Proc.

The nuclear incoherent π 0 photoproduction cross section from 12 C is evaluated at forward angles in the 4.0 to 6.0 GeV energy range using the multicollisional intranuclear cascade model MCMC. The model incorporates some improvements in comparison with previous versions associated with the momentum distribution (MD) for light nuclei—extracted from the available ( e , e ′ p ) data—as well as the evaluation of the shadowing effects during the photo‐nucleus interaction. The final results of the single and double differential cross sections at forward angles are very sensitive to the MD parameterizations due to the Pauli principle, which largely suppresses the cross sections for low momentum transfer. The attenuation of the nuclear cross section due to pion—nucleus final state interactions is approximately 40% (without nuclear shadowing), which is in nice agreement with the predictions from the Glauber model. The single and double π 0 differential cross sections are presented for possible applications for the interpretation of the inelastic background in the PrimEx experiment at the Jefferson Laboratory.

AIP Conf. Proc.

The TGV II (Telescope Germanium Vertical) facility is a low background spectrometer operated in Modane Underground Laboratory. It aims at the study of double electron capture of 106 Cd . The spectrometer is composed of 32 HPGe planar detectors interleaved with thin‐foil samples made of Cd‐106 enriched to 75% (total mass about 10 g). In 2006, the main run of phase I (1 year duration) was terminated yielding a new limit on half‐life for two‐neutrino double electron capture ( g.s. → g.s. ) in 106 Cd as 2.0×10 20   years . This limit is significantly higher (by almost three orders of magnitude) than those already published.

AIP Conf. Proc.

Time and energy spectra of gamma‐rays following muon capture in 40 Ar were measured. Muon life‐time in 40 Ar and isotope yields ( 38 Cl , 39 Cl , 40 Cl , 38 S , 39 S ) are presented.

AIP Conf. Proc.

Energy and time spectra of gamma‐rays following μ‐capture in natural Kr, Se, Cd and Sm, as well as isotopic enriched 82 Kr , 76 Se , 106 Cd and 150 Sm , have been measured. Total life‐times of muons in 150 Sm and different Kr isotopes, as well as partial μ‐capture rates to the excited states of 48 Sc , 76 As and 106 Ag , were extracted. These results are important for calculation of nuclear matrix elements of the 48 Ca , 76 Ge and 106 Cd 2β‐decay, respectively.

Phys.Rev.Lett.

We report the observation of the exclusive decay Bs0 -gt Ds- Ds+ at the 7.5 standard deviation level using 355 pb(-1) of data collected by the CDF II detector in p[overline p] collisions at sqrt(s) =1.96 TeV at the Fermilab Tevatron. We measure the relative branching ratio [script B] (Bs0 -gt Ds- Ds+ )/[script B] (B0-gt D-Ds+ )=1.44-0.44(+0.48) . Using the world average value for [script B] (B0-gt D-Ds+ ), we find [script B] (Bs0 -gt Ds- Ds+ )=(9.4-4.2(+4.4) )times10(-3). This provides a lower boun d Delta Gamma s(CP) /Gamma sgt= 2[script B] (Bs0 -gt Ds- Ds+ )gt1.2times10(-2) at 95% C.L.

Phys.Rev.Lett.

We report the first top quark mass measurement that uses a cross section constraint to improve the mass determination. This measurement is made with a dilepton $t\bar{t}$ event sample collected with the CDF II detector. From a data sample corresponding to an integrated luminosity of 1.2 fb$^{-1}$, we measure a top quark mass of $\rm{170.7^{+4.2}_{-3.9}(stat)\pm2.6(syst)}$ $\rm{\pm2.4(theory) GeV/{\it{c}}^{2}}$. The measurement without the cross section constraint results in a top quark mass of $\rm{169.7^{+5.2}_{-4.9}(stat)\pm3.1(syst) GeV/{\it{c}}^{2}}$.

Phys. Rev. Lett.

A direct measurement of the total decay width of the W boson G_W is presented using 350 pb-1 of data from ppbar collisions at sqrt(s) = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The width is determined by normalizing predicted signal and background distributions to 230185 W candidates decaying to enu and munu in the transverse-mass region 50 < M_T < 90 GeV and then fitting the predicted shape to 6055 events in the high-M_T region, 90 < M_T < 200 GeV. The result is G_W = 2032 +/- 45 (stat.) +/- 57 (syst.) MeV, consistent with the standard model expectation.

Phys.Rev.Lett.

We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.

Phys.Rev.Lett.

We report on the results of a search for standard model Higgs bosons produced in association with W bosons from p-pbar collisions at root s = 1.96 TeV. The search uses a data sample corresponding to approximately 1 fb-1 of integrated luminosity. Events consistent with the W to l-nu and H to b-bbar signature are selected by triggering on a high-pT electron or muon candidate and tagging one or two of the jet candidates as having originated from b quarks. A neural network filter rejects a fraction of tagged charm and light flavor jets, increasing the b-jet purity in the sample and thereby reducing the background to Higgs boson production. We observe no excess l-nu-b-bbar production beyond the background expectation, and we set 95% confidence level upper limits on the production cross section times branching fraction sigma(p-pbar to WH) times Br(H to b-bbar) ranging from 3.9 to 1.3 pb, for specific Higgs boson mass hypotheses in the range 110 to 150 GeV/c2, respectively.

Phys. Rev. D

We search for evidence of resonant top quark pair production in 955 pb-1 of p-pbar collisions at sqrt(s)=1.96 TeV recorded with the CDF II detector at the Fermilab Tevatron. For fully reconstructed candidate t-tbar events triggered on leptons with large transverse momentum and containing at least one identified b-quark jet, we compare the invariant mass spectrum of t-tbar pairs to the expected superposition of standard model t-tbar, non-t-tbar backgrounds, and a simple resonance model based on a sequential Z' boson. We establish upper limits for sigma(p-pbar to Z') times Br(Z' to t-tbar) in the Z' mass interval from 450 GeV/c2 to 900 GeV/c2. A topcolor leptophobic Z' is ruled out below 720 GeV/c2, and the cross section of any narrow Z'-like state decaying to t-tbar is found to be less than 0.64 pb at 95% C.L. for M(Z') above 700 GeV/c2.