Search

In this article I discuss a few aspects of exclusive decays of heavy mesons from the specific perspective of Kolya Uraltsev's contributions to this field. The selection of topics as well as their presentation reflects my personal view on Kolya's work and also includes some personal remarks related to my collaboration with him. [ABSTRACT FROM AUTHOR]

It is interesting to determine the fraction of the gluonium component in η and η′ which has been under serious discussion for many years. Measurements on different decay and/or production modes were employed in literatures, thus larger uncertainties were unavoidable. In this paper we suggest to determine the mixing angles of η-η′-G using the data of semileptonic decays of D and Ds. We extract the mixing angles ϕ′, ϕG and the model parameters simultaneously. Thanks to the new measurements carried out by CLEO Collaboration and there are sufficient decay modes to determine both the model parameters and mixing angles. The mixing angles from data are ϕ′ = (41.5 ± 2.0)° and sin ϕG = 0.00 ± 0.36. Even though the central value of sin ϕG is still zero, an upper bound is set. Moreover, as suggested in literature, η(1405) is a glueball candidate whereas in our picture, η(1405) may be identified as G with glueonium being its main content. Using all the model-parameters obtained above, we estimate the branching ratios of $D_s^+(D^+)\rightarrow Ge^+\nu_e$ where G is identified as η(1405). [ABSTRACT FROM AUTHOR]

The question if the Bose statistics is broken at the TeV scale is discussed. The decay of a new heavy spin-1 gauge boson Z′ into two photons, Z′ → γγ, is forbidden by the Bose statistics among other general principles of quantum field theory (Landau-Yang theorem). We point out that the search for this decay can be effectively used to probe the Bose symmetry violation at the CERN LHC. [ABSTRACT FROM AUTHOR]

We study the large branching ratios of B→ηK* decays and the time-dependent CP asymmetry SϕKS anomaly of B→ϕKS decay in a flavor changing Z′ model associated with flavor changing neutral currents at the tree level. Considering the right-handed flavor changing couplings and setting ξLL = ξRL = ξLR = ξRR = ξ, we obtain 0.011 < ξ < 0.0131, this parameter region could give a simultaneous explanation to these anomalies of B→ηK* and B→ϕKS decays. The results are consistent with the constraints and the assumptions of some references. [ABSTRACT FROM AUTHOR]

The decay modes J/ψ → γπ0, γη, and γη′ are analyzed using a data sample of 58 million J/ψ decays collected with the BESII detector at the BEPC. The branching fractions are determined to be $Br(J/\psi\to \gamma\pi^0) = (3.13^{+0.65}_{-0.47})\times 10^{-5}$, Br(J/ψ → γη) = (11.23 ± 0.89) × 10-4, and Br(J/ψ → γη′) = (5.55 ± 0.44) × 10-3, where the errors are combined statistical and systematic errors. The ratio of partial widths and the singlet-octet pseudoscalar mixing angle of η-η′ system is determined. The η′ → γπ+π- decay dynamics is studied using 22,000 reconstructed J/ψ → γη′ → γγπ+π- events, the π+π- mass spectrum is fitted using different theoretical descriptions. The preliminary results show that only the ρ(770) is not enough to describe the η′ → γπ+π- decay process and a non-ρ(770) contribution is needed. [ABSTRACT FROM AUTHOR]

A systematic calculation for the transition form factors of heavy to light mesons (B, Bs, D, Ds → π, K, η, ρ, K*, ω, ϕ) is carried out by using light-cone sum rules in the framework of heavy quark effective field theory. The heavy quark symmetry at the leading order of 1/mQ expansion enables us to reduce the independent wave functions and establish interesting relations among form factors. Some relations hold for the whole region of momentum transfer. The meson distribution amplitudes up to twist-4 including the contributions from higher conformal spin partial waves and light meson mass corrections are considered. The CKM matrix elements |Vub|, |Vcs| and |Vcd| are extracted from some relatively well-measured decay channels. A detailed prediction for the branching ratios of heavy to light meson decays is then presented. The resulting predictions for the semileptonic and radiative decay rates of heavy to light mesons (B, Bs, D, Ds → π, K, η, ρ, K*, ω, ϕ) are found to be compatible with the current experimental data and can be tested by more precise experiments at B-factory, LHCb, BEPCII and CLEOc. [ABSTRACT FROM AUTHOR]

We report the recent results of $D^0\mbox{-}\overline{D}{}^0$ mixing and CP violation studies in D0 decays from Belle, which include the time-dependent measurements of D0 wrong-sign semileptonic decay, wrong-sign hadronic decay to K+π-, as well as the wrong-sign ratio of hadronic decays to K+π-n(π). [ABSTRACT FROM AUTHOR]

Recent results from leptonic and semi-leptonic charm decays at the BABARB–factory are presented. The measurement of fDs from the $D_{s}^+\rightarrow\mu^+\nu$ channel is presented. Form-factor studies from the $D^0\rightarrow K^+e^-\bar{\nu}_{e}$ channel are described along with a search for flavor-changing neutral-current $X_c^+\to h^+\ell^+\ell^{'-}$ decays. [ABSTRACT FROM AUTHOR]

We present a preliminary search for $D^0\mbox{-}\overline{D}{}^0$ mixing using the decays D0 → K+π-π0, additionally presenting Dalitz-plot distributions and a measurement of the branching ratio for this mode. A new tagging technique is used to produce the doubly Cabibbo-suppressed Dalitz plot, which in turn is used to motivate the method used for the D-mixing search. We analyze 230.4 fb-1 of data collected from the BABAR detector at the PEP-II collider. Assuming CP conservation, we find RM < 0.054% with 95% confidence, and we estimate that the data are consistent with no mixing at a 4.5% confidence level. We present D-mixing results both with and without the assumption of CP conservation. [ABSTRACT FROM AUTHOR]

We present a preliminary search for $D^0\mbox{-}\overline{D}{}^0$ mixing using the decays D0 → K+π-π0, additionally presenting Dalitz-plot distributions and a measurement of the branching ratio for this mode. A new tagging technique is used to produce the doubly Cabibbo-suppressed Dalitz plot, which in turn is used to motivate the method used for the D-mixing search. We analyze 230.4 fb-1 of data collected from the BABAR detector at the PEP-II collider. Assuming CP conservation, we find RM < 0.054% with 95% confidence, and we estimate that the data are consistent with no mixing at a 4.5% confidence level. We present D-mixing results both with and without the assumption of CP conservation. [ABSTRACT FROM AUTHOR]

We summarize the theoretical virtues of the rare $K\to\pi\nu\bar\nu$ decays and emphasize the unique role of $K_{\rm L} \to\pi^0\nu\bar\nu$ in probing the nature of physics beyond the Standard Model, in particular concerning possible new sources of CP violation and flavor-symmetry breaking. A brief summary of the prospects for the measurement of the $K_{\rm L} \to \pi^0\nu\bar\nu$ rate is also given. [ABSTRACT FROM AUTHOR]

We report the results of the first computation related to the study of the spectator effects in the rare decay mode B→Kγγ within the framework of Standard Model. It is found that the account of these effects results in the enhancement factor for the short-distance reducible contribution to the branching ratio. [ABSTRACT FROM AUTHOR]

A study of the decay $B^+ \to p{\bar p}K^+$ is performed using 81 fb-1 of data collected at the ϒ(4S) with the BABAR detector at PEP-II. The branching fraction of $B^+ \to p{\bar p}K^+$ is measured to be (6.7 ± 0.9 ± 0.6) × 106. An upper limit on the branching fraction of $B^+ \to \Theta^{*++}{\bar p}$, where Θ*++ is a narrow state decaying to pK+, is set to be 1.5 × 10-7 for 1.43 < m(Θ*++) < 1.85 GeV/c2 at 90% confidence level. All results are preliminary. [ABSTRACT FROM AUTHOR]

We present results on time-dependent CP asymmetries in $f_0(980)(\to \pi^+\pi^-)K^0_S$ and B0 → K+K-K0. The measurements use a data sample consisting of approximately $209(f_0(980)(\to \pi^+\pi^-)K^0_S)$ and 227(B0 → K+K-K0) million B-meson pairs recorded at the ϒ(4S) resonance with the BABAR detector at the PEP-II B-meson Factory at SLAC. From a time-dependent maximum likelihood fit, we measure for $B^0 \to f_0(980)(\to \pi^+\pi^-)K^0_S$: the mixing-induced CP violation parameter $S_{f_0 K} = -0.95^{+0.32}_{-0.23} ({\rm stat}) \pm 0.10 ({\rm syst})$ and the direct CP violation parameter Cf0K = -0.24 ± 0.31 (stat) ± 0.15 (syst). From a simultaneous fit to $B^0 \to \phi K^0_S$ and $B^0 \to \phi K^0_L$ decays, we find: $S_{\phi K^0_S}= -S_{\phi K^0_L} = +0.50 \pm 0.25 ({\rm stat})^{+0.07}_{-0.04} ({\rm syst})$ and CϕK = 0.00 ± 0.23 (stat) ± 0.05 (syst). For $B^0 \to K^+K^-K^0_S$ decays with $B^0 \to \phi K^0_S$ decays excluded, we find: $S_{KKK({\rm no}\ \phi K^0_S)} = -0.42 \pm 0.17 ({\rm stat}) \pm 0.04 ({\rm syst})$ and $C_{KKK({\rm no}\ \phi K^0_S)} = +0.10 \pm 0.14 ({\rm stat}) \pm 0.06 ({\rm syst})$. From the $B^0 \to K^+K^-K^0_S$ decays with $B^0 \to \phi K^0_S$ decays excluded, we extract the fraction of CP-even final states from angular moments feven = 0.89 ± 0.08 ± 0.06. [ABSTRACT FROM AUTHOR]

Measurement of the Bs oscillation frequency via Bs mixing analyses provides a powerful constraint on the CKM matrix elements. The study of Bd oscillations is an important step towards Bs mixing and preliminary measurements of Δmd have been made with ~250 pb-1 of data collected with the upgraded Run II DØ detector. Different flavor tagging algorithms have been developed and are being optimized for use on a large set of Bs mesons that have been reconstructed in different semileptonic decay modes. [ABSTRACT FROM AUTHOR]

We present new measurements of CP-violation parameters in B0 → ϕK0, $K^+K^-K^0_S$, $f_0(980)K^0_S$, $\eta' K^0_S$, $\omega K^0_S$, $K^0_S \pi^0$, and $K^{\ast 0}\gamma (K^{\ast 0} \to K^0_S \pi^0)$ decays based on a sample of $275 \times 10^6 B{\bar B}$ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. All results are preliminary. [ABSTRACT FROM AUTHOR]

We present measurements of branching fractions and CP asymmetries of several B- → D(*)0K(*)- decays, with the D(*)0 decaying to CP-even, CP-odd, and flavor eigenstates, that can constrain the CP angle γ as well as the amplitude ratio rb = A(B → u)/A(B → c), using methods proposed by Gronau, London and Wyler or Atwood, Dunietz and Sony1. We use data collected with the BABAR detector at the PEP-II asymmetric energy e+e- collider at SLAC. [ABSTRACT FROM AUTHOR]

The Belle experiment has measured branching fractions and CP asymmetries for the charmless decays B0 → π+π- and B0 → ρ±π∓. From these measurements, constraints upon the CKM angle ϕ2 can be obtained. These constraints indicate that ϕ2 is around 100°. [ABSTRACT FROM AUTHOR]

Relative branching fractions of $B^0_{d,s} \to h^+h'^{-}$ decays (where h, h′ = K or π) and the direct CP asymmetry ${\mathcal A}_{CP}$ in the $B^0_d \to K^+\pi^-$ mode are measured with 179 ± 11 pb-1 of data collected at $\sqrt{s} = 1.96\ {\rm TeV}$ using the CDF II detector at the Fermilab Tevatron $p{\bar p}$ collider. The first branching-fraction measurement of a $B^0_s$ meson to two pseudoscalars, ${\mathcal B}({B^0_s \to K^+K^-})$, and a search for the baryon mode $\Lambda^0_b \to p^+h^-$ are also presented, in addition to branching-fraction limits on the rare channels $B^0_s \to K^+\pi^-$, $B^0_d \to K^+K^-$, and $B^0_s \to \pi^+\pi^-$. [ABSTRACT FROM AUTHOR]

We present preliminary measurements of branching fractions and direct CP violating asymmetries in charmless twobody B decays, obtained with the BABAR detector using a sample of 227 M $\Upsilon(4S)\to B{\bar B}$ decays. We report the first observation of $B^0 \to K^0{\bar K}^0$ and the first observation of direct CP violation in B0 → K+π- decays. [ABSTRACT FROM AUTHOR]

We present measurements of B → PV and VV decays based on 140 fb-1 of data recorded at the ϒ(4S) resonance with the Belle detector at the KEKB e+e- storage ring. Branching fractions of B → ηK*, ηρ+, ρπ0, and ρ+K* are measured; while upper limits of B → ηρ0 and ρ0K* decays are given. The polarization study of B → ϕK* is also updated. [ABSTRACT FROM AUTHOR]

We measure the mass of the top quark using 162 pb-1 of data collected by the CDF experiment at the Fermilab Tevatron in Run II. The decay chain $t{\bar t} \to bq{\bar q}{\bar b}l\nu$ is studied using a novel technique called the Multivariate Template Method (MTM). Using this technique we obtain a result of $M_{top} = 179.6^{+6.4}_{-6.3}({\rm stat.}) \pm 6.8({\rm syst.})\ {\rm GeV}/c^2$ for the top quark. [ABSTRACT FROM AUTHOR]

We measure the ratio R = B(t→Wb)/B(t→Wq) in top-quark decays at CDF. R is determined from the relative rates of identified b jets in $t{\bar t}$ decays reconstructed both in the lepton-plus-jets and dilepton final states. We obtain R>0.62 at the 95% CL, consistent with Standard Model expectations. [ABSTRACT FROM AUTHOR]

I briefly review CP violation in the B system, concentrating on B→πK decays. I discuss how to deal with electroweak-penguin contributions to these decays using flavour SU(3). With these, I show that the entire unitarity triangle can be extracted from measurements of B→πK decays. Finally, I examine the signals for new physics in these decays and the possibilities for measuring them. [ABSTRACT FROM AUTHOR]

We describe here a method for detecting physics beyond the standard model via CP violation in B→ρπ decays. Using a Dalitz-plot analysis to obtain α, along with an analytical extraction of the various tree (T) and penguin (P) amplitudes, we obtain a criterion for the absence of new physics (NP). This criterion involves the comparison of the measured |P/T| ratio with its value as predicted by QCD factorization. We show that the detection of NP via this method has a good efficiency when compared with the corresponding technique using B→ππ decays. [ABSTRACT FROM AUTHOR]

Recent advances in improving extractions of |Vcb| and mb from spectra of semileptonic inclusive B decay are reported. Results of a general moment analysis of the lepton energy spectrum and the hadronic invariant mass spectrum are summarized. The calculation of the general $\mathcal{O}(\alpha_s)$ structure functions for semileptonic B decay is reported, which has allowed the calculation of the $\mathcal{O}(\alpha_s \Lambda_{\rm QCD}/m_b)$ terms for the hadronic invariant mass moments to be carried out. Recent theoretical advances and improvements in experimental data has allowed extractions of the CKM matrix element |Vcb| to improve to the 2% level. [ABSTRACT FROM AUTHOR]

The three body decays $B\to D^{(*)} \bar{D}^{(*)} K_s$, may be used to measure both sin2β and cos2β. Crucial to the cos2β measurement is the resonant contribution to the three body decay from p-wave excited Ds, states. If these p-wave states are the newly discovered Ds(2317) and Ds(2460) then they are below the D(*)K threshold and hence do not contribute to $B\to D^{(*)} \bar{D}^{(*)} K_s$. The three body decays can then be used to measure sin2β without resonant dilution and to look for new physics in $b\to c\bar{c}s$ transition. [ABSTRACT FROM AUTHOR]

We discuss the C, P, T, CP, CPT symmetries and possible searches for violation of these symmetries in positronium decays. [ABSTRACT FROM AUTHOR]

We propose an experiment to search for invisible decays of orthopositronium (o-Ps) with the 90% confidence sensitivity in the branching ratio as low as 10-8. Evidence for this decay mode would unambiguosly signal new physics: either the existence of extra–dimensions or fractionally charged particles or new light gauge bosons. The experimental approach and the detector components of the proposed experiment are described. [ABSTRACT FROM AUTHOR]

Among several interesting motivations for experimenting with orthopositronium (o-Ps) in vacuum the most exciting one is probably related to the search for the dark matter of a mirror-type. The mirror matter is predicted to exist if parity is an unbroken symmetry of the vacuum. The existence of the mirror matter, which in addition to gravity communicates with our world through photon-mirror photon mixing, would result in orthopositronium (o-Ps) to mirror orthopositronium (o-Ps') oscillations. The experimental signature of this effect is the invisible decay of o-Ps in vacuum. We discuss an experiment to search for o-Ps→invisible decay in vacuum with a sensitivity in the branching ratio Br(o-Ps→invisible)≃10-7, which is an order of magnitude better than the present limit on this decay mode from the Big Bang Nucleosynthesis. Details of the design are presented. The effect of various environments on o-Ps→o-Ps' oscillation probability is also discussed. [ABSTRACT FROM AUTHOR]

Recent charm results are reviwed with special attention to spectroscopy and hadronic decays. Two new states decaying to $D_s^+\pi^0$ and $D_s^{*+}\pi^0$ were recently discovered by BaBar and CLEO. In the baryon sector, the first observation of a doubly charmed baryon was announced by SELEX. Several amplitude analysis on charm hadronic decays are also discussed. [ABSTRACT FROM AUTHOR]

We review recent developments in QCD pertaining to its application to weak decays of heavy hadrons. We concentrate on exclusive rare and nonleptonic B-meson decays, discussing both the theoretical framework and phenomenological issues of current interest. [ABSTRACT FROM AUTHOR]

Recent data from the rare decays of B mesons into hadronic final states is presented from BaBar, Belle, CDF and CLEO. Where possible the data are compared with theoretical calculations, with the twin aims of further testing the Standard Model and searching for evidence of new physics. A brief description is given of some theoretical approaches in order to indicate which decays are the most sensitive for further study. [ABSTRACT FROM AUTHOR]

This report summarizes the latest experimental results on radiative and electroweak rare B meson decays. These rare decay processes proceed through the Flavor-Changing-Neutral-Current processes, and thus are sensitive to the postulated new particles in the theories beyond the Standard Model. Experiments at e+e- colliders, Belle, BaBar and CLEO, have been playing the dominant role, while the CDF and D0 experiments have just started to provide new results from Tevatron Run-II. The most significant achievement is the first observation of the decay B→K*ℓ+ℓ-, which opens a new window to search for new physics in B meson decays. [ABSTRACT FROM AUTHOR]

Recent measurements in the charm sector are reviewed, concentrating on results which are sensitive to New Physics effects. The scope of the presentation includes $D^0-{\bar D}^0$ mixing searches, a CPT/Lorentz invariance study, and a range of searches for rare and forbidden decays. Results from the BaBar, Belle, CDF, CLEO, and FOCUS collaborations are presented, including an important first observation. [ABSTRACT FROM AUTHOR]

Ultrahigh energy neutrinos can provide important information about the distant astronomical objects and the origin of the Universe. Precise knowledge about neutrino interactions and production rates is essential for estimating background, expected fluxes and detection probabilities. In this paper we review the applications of the high energy QCD to the calculations of the interaction cross-sections of the neutrinos. We also study the production of the ultrahigh energy neutrinos in the atmosphere due to the charm and beauty decays. [ABSTRACT FROM AUTHOR]

We study on-shell decays of light vector meson resonances ρ, K* and ϕ in the framework of chiral constituent quark model using resummation calculations. Such studies are necessary for showing that dynamics described by chiral Lagrangian works well at this energy scale. The effective action is derived by a proper vertex method, where resummation of all orders of momentum expansion is accomplished. Also studied are the loop effects of pseudoscalar meson, which play an important role at this energy scale. The numerical results agree well with the experimental data. A new method to explore the chiral symmetry spontaneously breaking (CSSB) is proposed. It is found that the unitarity of the effective meson theory resulted from resummation derivations demands an upper-limit to the momentum of vector meson. This upper-limit, being critical point, is just the energy scale of CSSB, and is found to be flavor-dependent. [ABSTRACT FROM AUTHOR]

The isoscalar SU(3) factors can be used to derive relations between different decay modes of one meson as well as relations between decays of different mesons of the same nonet. These relations are derived assuming the OZI rule. [ABSTRACT FROM AUTHOR]

A general formulation has been given for constructing covariant helicity-coupling amplitudes involving two-body decays with arbitrary integer spins. In order to illustrate the principles, the case of a spin-1 object decaying into spin-2 and spin-1 particles is treated in some detail. Also given are the helicity-coupling amplitudes for a spin-2 object decaying into a spin-2 and a spin-0 particle. [ABSTRACT FROM AUTHOR]

The spectrum of stable electrically and magnetically charged supersymmetric particles can change discontinously due to the decay of these particles as the vacuum on the Coulomb branch is varied. We show that this decay process is well described by semiclassical field configurations even when it occurs at strong coupling. The resulting picture of the stable supersymmetric spectrum is a generalization of the "string web" picture of these states found in string constructions. The spectrum of stable electrically and magnetically charged supersymmetric particles can change discontinously due to the decay of these particles as the vacuum on the Coulomb branch is varied. We show that this decay process is well described by semiclassical field configurations even when it occurs at strong coupling. The resulting picture of the stable supersymmetric spectrum is a generalization of the "string web" picture of these states found in string constructions. The spectrum of stable electrically and magnetically charged supersymmetric particles can change discontinously due to the decay of these particles as the vacuum on the Coulomb branch is varied. We show that this decay process is well described by semiclassical field configurations even when it occurs at strong coupling. The resulting picture of the stable supersymmetric spectrum is a generalization of the "string web" picture of these states found in string constructions. [ABSTRACT FROM AUTHOR]

The CLEO Collaboration has an active charm physics effort underway using 14fb[sup -1] of CLEO II and CLEO II.V data. A recent analysis of the time dependence of the 'wrong-sign' decay D[sup 0] → K[sup +]π[sup -] has placed limits on x&prime' and y', the amplitudes that describe mixing in the Do system. The 95% CL limits, with no assumptions about CP violation, are (½)x&prime² < 0.041% and -5.8% < y' < 1.0%. Measurements of DO decay rates to CP eigenstates, D[sup 0] &rar; K[sup -]K[sup +] and D[sup 0] → τ[sup -]π[sup +], provide preliminary CP asymmetry measurements A[sub CP](KK) = 0.04% ± 2.18%(stat) ± 0.84%(syst) and A[sub CP](ππ) = 1.94% ± 3.22%(stat) ± 0.84%(syst). A third analysis provides the first preliminary evidence for the decay D[sup 0] &rar; K[sup +]π[sup -]π[sup 0]. Finally, a new Dalitz analysis of the decay D[sup 0] → K[sup -]π[sup +]τ[sup 0] gives preliminary evidence for several new resonance contributions in this decay and also requires the presence of a significant non-resonant component. [ABSTRACT FROM AUTHOR]

Using data recorded by the CLEO II and CLEO II.V detectors at CESR, we report new measurements of the σ[sup ++, sub c] and σ[sup 0, sub c] masses, and the first measurements of their intrinsic widths. The measured widths of these particles agree with the theoretical predictions. We also present a new measurement of the mass of the σ[sup +, sub c] charmed baryon, observed by its decay into γ[sup +, sub c] π[sup 0], and the first observation of a new state which is identified as the J[sup P] = 3/2[sup +] &sigma[sup *+, sub c], the isospin partner of the previously discovered σ[sup *++, sub c] and σ[sup *0, sub c]. The quark model predicts many excited states of γ[sub c] and σ[sub c] baryons, some of which cannot, because of quantum mechanical conservations rules, decay via one pion to the ground state. We present results of a search for such states decaying via dipion decays into the ground state λ[sup +, sub c] Recently, the CLEO collaboration also reported the existence of a pair of excited Ξ[sub c] particles decaying into Ξ[sup *, sub c]π. These are thought to be orbitally excited Ξ[sub c]'s with J[sup P] = 3/2[sup -]. Here we present a search for the analogous J[sup P] = &frac12-; particles, which are predicted to decay into Ξ'[sub c]τ. [ABSTRACT FROM AUTHOR]

We show that in supersymmetric extensions of the Standard Model gluino box diagrams can yield a large CP-violating δI = 3/2 contribution to s → d&qmacr;q flavor-changing neutral current processes, which feeds into the I = 2 isospin amplitude in K → ππ decays. This contribution only requires moderate mass splitting between the right-handed squarks ũ[sub R[ and &dtilde;[sub R], and persists for squark masses of order 1 TeV. Taking into account current bounds on Imδ[sup LL, sub sd] from K-&Kmacr; mixing, the resulting contribution to ∈'/∈ could naturally be an order of magnitude larger than the measured value. [ABSTRACT FROM AUTHOR]

A measurement of the Michel parameters, η, ρ, ξ, ξδ, and the average ν[sub τ] helicity, h[sub ν[sub τ]], in τ lepton decays is described together with the first measurement of the tensor coupling in the weak charged current. The results are consistent with the V - A structure of the weak charged current in decays of the τ lepton. [ABSTRACT FROM AUTHOR]

We use the full ALEPH data set at LEP1 of four million hadronic Z decays to measure CP asymmetries in the B[sup 0, sub d] decay. From 23 B[sup 0, sub d] → J/ψK[sup 0, sub s] decays the value sin 2β = 0.84[sup +0.82, sub -1.04] ± 0.16 is measured, while from two measurements of the semilep-tonic asymmetry a[sub CP] using inclusive b decays we obtain a[sub CP] = -0.013 ± 0.026. [ABSTRACT FROM AUTHOR]

We propose a new method for measuring the CKM phase γ using the partial rates for CP-tagged B[sub s] decays. Such an experiment could be performed at a very high luminosity symmetric e[sup +]e[sup -] collider operating at the γ(5S) resonance, where the B[sub s]&Bmacr;[sub s] state is produced in a state of definite CP. We also discuss CP-tagging in the B[sub d] system at the τ(45), where a time-dependent analysis is required to compensate for the anticipated large CP violation in B[sub d] - &Bmacr;[sub d] mixing. [ABSTRACT FROM AUTHOR]

A new measurement of Re(∈'/∈) by the NA48 collaboration using data collected in 1998 is presented. The preliminary result is Re(∈'/∈) = (12.2 ± 2.9 (star) ± 4.0 (sys)) × 10[sup -4]. The combination with the previous measurement using the 1997 data yields Re(∈'/∈) = (14.0 ± 4.3) × 10[sup -4]. This result confirms the existence of direct CP violation. The uncertainty on this measurement will be improved in the future. [ABSTRACT FROM AUTHOR]

This work gives a specific proposal for how K[sub L] → ππ may be caused by gravitational forces. A consequence is that η+- varies with a very long period. [ABSTRACT FROM AUTHOR]

Results of searches for the signatures of promptly decaying light gravitinos are presented, based on data collected using the OPAL detector at LEP. This paper focuses primarily on updates to the results of published analyses of approximately 182 pb[sup -1] taken at √s = 189 GeV in 1998. These updates are based on analysis of data collected in the energy range of √s = 200 - 209 GeV in the year 2000. All results from this data sample are preliminary. [ABSTRACT FROM AUTHOR]

We have analyzed 1144 days of Super-Kamiokande data for 13 of the more than 40 possible nucleon decay modes. We have studied p → e[sup +]π[sup 0], and twelve other two particle B-L conserving decay modes including those with kaons that are preferred in supersymmetric theories. Most modes are currently free of candidate events. In all cases the number of candidates is consistent with atmospheric neutrino induced backgrounds. We have calculated 90% confidence level single sided lower limits on the lifetime of the neutron and proton (divided by the unknown branching ratio) for the studied modes. All of our lower limits are higher than previous best limits by a factor of 2-10. Our limit for p → e[sup +]π[sup 0] is now 4.4 × 10[sup 33] years. [ABSTRACT FROM AUTHOR]