104 research outputs found

    Direct CP Violation, Branching Ratios and Form Factors BπB \to \pi, BKB \to K in BB Decays

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    The BπB \to \pi and BKB \to K transitions involved in hadronic B decays are investigated in a phenomenological way through the framework of QCD factorization. By comparing our results with experimental branching ratios from the BELLE, BABAR and CLEO Collaborations for all the B decays including either a pion or a kaon, we propose boundaries for the transition form factors BπB \to \pi and BKB \to K depending on the CKM matrix element parameters ρ\rho and η\eta. From this analysis, the form factors required to reproduce the experimental data for branching ratios are FBπ=0.31±0.12F^{B \to \pi}= 0.31 \pm 0.12 and FBK=0.37±0.13F^{B \to K}= 0.37\pm 0.13. We calculate the direct CP violating asymmetry parameter, aCPa_{CP}, for Bπ+ππB \to \pi^{+} \pi^{-} \pi and Bπ+πKB \to \pi^{+} \pi^{-} K decays, in the case where ρω\rho-\omega mixing effects are taken into account. Based on these results, we find that the direct CP asymmetry for Bπ+ππB^{-} \to \pi^{+} \pi^{-} \pi^{-}, Bˉ0π+ππ0\bar{B}^{0} \to \pi^{+} \pi^{-} \pi^{0}, Bπ+πKB^{-} \to \pi^{+} \pi^{-} K^{-}, and Bˉ0π+πKˉ0\bar{B}^{0} \to \pi^{+} \pi^{-} \bar{K}^{0}, reaches its maximum when the invariant mass π+π\pi^{+} \pi^{-} is in the vicinity of the ω\omega meson mass. The inclusion of ρω\rho-\omega mixing provides an opportunity to erase, without ambiguity, the phase uncertainty mod(π)(\pi) in the determination of the CKM angles α\alpha in case of bub\to u and γ\gamma in case of bsb \to s.Comment: 74 pages, 15 figures, 8 tables. A few misprints corrected, two references adde

    Hadron Spectroscopy: Theory and Experiment

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    Many new results on hadron spectra have been appearing in the past few years thanks to improved experimental techniques and searches in new channels. New theoretical techniques including refined methods of lattice QCD have kept pace with these developments. Much has been learned about states made of both light (u, d, and s) and heavy (c, b) quarks. The present review treats light-quark mesons, glueballs, hybrids, particles with a single c or b quark, charmonium, and bottomonium states. Some prospects for further study are noted.Comment: 29 pages, 9 figures, to be published in Journal of Physics G. Further updating of reference

    Transverse Momentum Dependent Parton Distribution/Fragmentation Functions at an Electron-Ion Collider

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    We present a summary of a recent workshop held at Duke University on Partonic Transverse Momentum in Hadrons: Quark Spin-Orbit Correlations and Quark-Gluon Interactions. The transverse momentum dependent parton distribution functions (TMDs), parton-to-hadron fragmentation functions, and multi-parton correlation functions, were discussed extensively at the Duke workshop. In this paper, we summarize first the theoretical issues concerning the study of partonic structure of hadrons at a future electron-ion collider (EIC) with emphasis on the TMDs. We then present simulation results on experimental studies of TMDs through measurements of single spin asymmetries (SSA) from semi-inclusive deep-inelastic scattering (SIDIS) processes with an EIC, and discuss the requirement of the detector for SIDIS measurements. The dynamics of parton correlations in the nucleon is further explored via a study of SSA in D (`D) production at large transverse momenta with the aim of accessing the unexplored tri-gluon correlation functions. The workshop participants identified the SSA measurements in SIDIS as a golden program to study TMDs in both the sea and valence quark regions and to study the role of gluons, with the Sivers asymmetry measurements as examples. Such measurements will lead to major advancement in our understanding of TMDs in the valence quark region, and more importantly also allow for the investigation of TMDs in the sea quark region along with a study of their evolution.Comment: 44 pages 23 figures, summary of Duke EIC workshop on TMDs accepted by EPJ

    SUSY breaking mediation mechanisms and (g-2)_\mu, B -> X_s \gamma, B -> X_{s} l^+ l^- and B_s -> \mu^+ \mu^-

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    We show that there are qualitative differences in correlations among (g2)μ(g-2)_{\mu}, BXsγB\to X_s \gamma, BXsl+lB \to X_{s} l^+ l^- and Bsμ+μB_s \to \mu^+ \mu^- in various SUSY breaking mediation mechanisms: minimal supergravity (mSUGRA), gauge mediation (GMSB), anomaly mediation (AMSB), gaugino mediation (g~\tilde{g}MSB), weakly and strongly interacting string theories, and DD brane models. After imposing the direct search limits on the Higgs boson and SUSY particle search limits and BXsγB\to X_s \gamma branching ratio, we find all the scenarios can accommodate the aμ(g2)μ/2a_\mu \equiv (g-2)_\mu /2 in the range of (a few tens)×1010\times 10^{-10}, and predict that the branching ratio for BXsl+lB\to X_s l^+ l^- can differ from the standard model (SM) prediction by ±20\pm 20 % but no more. On the other hand, the Bsμ+μB_s \to \mu^+ \mu^- is sensitive to the SUSY breaking mediation mechanisms through the pseudoscalar and stop masses (mAm_A and mt~1m_{\tilde{t}_1}), and the stop mixing angle. In the GMSB with a small messenger number, the AMSB, the g~\tilde{g}MSB and the noscale scenarios, one finds that B(Bsμ+μ)2×108B(B_s \to \mu^+ \mu^-) \lesssim 2 \times 10^{-8}, which is below the search limit at the Tevatron Run II. Only the mSUGRA or string inspired models can generate a large branching ratio for this decay.Comment: 40 pages, 21 figures (to appear in JHEP

    Transverse Spin Structure of the Nucleon through Target Single Spin Asymmetry in Semi-Inclusive Deep-Inelastic (e,eπ±)(e,e^\prime \pi^\pm) Reaction at Jefferson Lab

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    Jefferson Lab (JLab) 12 GeV energy upgrade provides a golden opportunity to perform precision studies of the transverse spin and transverse-momentum-dependent structure in the valence quark region for both the proton and the neutron. In this paper, we focus our discussion on a recently approved experiment on the neutron as an example of the precision studies planned at JLab. The new experiment will perform precision measurements of target Single Spin Asymmetries (SSA) from semi-inclusive electro-production of charged pions from a 40-cm long transversely polarized 3^3He target in Deep-Inelastic-Scattering kinematics using 11 and 8.8 GeV electron beams. This new coincidence experiment in Hall A will employ a newly proposed solenoid spectrometer (SoLID). The large acceptance spectrometer and the high polarized luminosity will provide precise 4-D (xx, zz, PTP_T and Q2Q^2) data on the Collins, Sivers, and pretzelocity asymmetries for the neutron through the azimuthal angular dependence. The full 2π\pi azimuthal angular coverage in the lab is essential in controlling the systematic uncertainties. The results from this experiment, when combined with the proton Collins asymmetry measurement and the Collins fragmentation function determined from the e+^+e^- collision data, will allow for a quark flavor separation in order to achieve a determination of the tensor charge of the d quark to a 10% accuracy. The extracted Sivers and pretzelocity asymmetries will provide important information to understand the correlations between the quark orbital angular momentum and the nucleon spin and between the quark spin and nucleon spin.Comment: 23 pages, 13 figures, minor corrections, matches published versio

    Studies of the Decay B+- -> D_CP K+-

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    We report studies of the decay B+- -> D_CP K+-, where D_CP denotes neutral D mesons that decay to CP eigenstates. The analysis is based on a 29.1/fb data sample of collected at the \Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+ e- storage ring. Ratios of branching fractions of Cabibbo-suppressed to Cabibbo-favored processes involving D_CP are determined to be B(B- -> D_1 K-)/B(B- -> D_1 pi-)=0.125 +- 0.036 +- 0.010 and B(B- -> D_2 K-)/B(B- -> D_2 pi-)=0.119 +- 0.028 +- 0.006, where indices 1 and 2 represent the CP=+1 and CP=-1 eigenstates of the D0 - anti D0 system, respectively. We also extract the partial rate asymmetries for B+- -> D_CP K+-, finding A_1 = 0.29 +- 0.26 +- 0.05 and A_2 = -0.22 +- 0.24 +- 0.04.Comment: 10 pages, 2 figures, submitted to Physical Review Letter

    Measurement of the energy dependence of the e+^{+}e^{-}BB B\overline{B} , BB B{\overline{B}}^{\ast } and BB {B}^{\ast }{\overline{B}}^{\ast } exclusive cross sections

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    Abstract We report the first measurement of the exclusive cross sections e + e − → B B ¯ BB B\overline{B} , e + e − → B B ¯ ∗ BB B{\overline{B}}^{\ast } , and e + e − → B ∗ B ¯ ∗ BB {B}^{\ast }{\overline{B}}^{\ast } in the energy range from 10.63 GeV to 11.02 GeV. The B mesons are fully reconstructed in a large number of hadronic final states and the three channels are identified using a beam-constrained-mass variable. The shapes of the exclusive cross sections show oscillatory behavior with several maxima and minima. The results are obtained using data collected by the Belle experiment at the KEKB asymmetric-energy e + e − collider

    Measurements of the D-sJ resonance properties

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    We report measurements of the properties of the D-sJ(+)(2317) and D-sJ(+)(2457) resonances produced in continuum e(+)e(-) annihilation near roots=10.6 GeV. The analysis is based on an 86.9 fb(-1) data sample collected with the Belle detector at KEKB. We determine the masses to be M(D-sJ(+)(2317))=2317.2+/-0.5(stat)+/-0.9(syst) MeV/c(2) and M(D-sJ(+)(2457))=2456.5+/-1.3(stat)+/-1.3(syst) MeV/c(2). We observe the radiative decay mode D-sJ(+)(2457)-->D(s)(+)gamma and the dipion decay mode D-sJ(+)(2457)-->D(s)(+)pi(+)pi(-) and determine their branching fractions. No corresponding decays are observed for the D-sJ(2317) state. These results are consistent with the spin-parity assignments of 0(+) for the D-sJ(2317) and 1(+) for the D-sJ(2457)

    Measurement of the resonant and nonresonant branching ratios in Ξ0^{0}c_{c} → Ξ0^{0}K+^{+}K^{-}

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    First measurement of the CKM angle ϕ3_{3} withS B±^{\pm} → D(KS0 {K}_{\mathrm{S}}^0 π+^{+}^{-}π0^{0}) K±^{\pm} decays

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    We present the first model-independent measurement of the CKM unitarity triangle angle ϕ3 using B±→ D(K0Sπ+π−π0) K± decays, where D indicates either a D0 or D¯¯¯¯0 meson. Measurements of the strong-phase difference of the D →K0Sπ+π−π0 amplitude obtained from CLEO-c data are used as input. This analysis is based on the full Belle data set of 772 × 106BB¯¯¯¯ events collected at the Υ(4S) resonance. We obtain ϕ3 = (5.7+10.2−8.8±3.5±5.7)° and the suppressed amplitude ratio rB = 0.323±0.147±0.023±0.051. Here the first uncertainty is statistical, the second is the experimental systematic, and the third is due to the precision of the strong-phase parameters measured from CLEO-c data. The 95% confidence interval on ϕ3 is (−29.7, 109.5)°, which is consistent with the current world average
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