B Physics and CP Violation

The following sections are included:

• Preface

• Acknowledgement

• Workshop Organization

• CONTENTS

We present a measurement of the Standard Model CP violation parameter sin 2ɸ₁ based on a 10.5 fb^-1 data sample collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric e⁺ e^- collider. One neutral B meson is reconstructed in the J/ψK_S, ψ(2S)K_S, χ_c1K_S, η_cK_S, J/ψK_L or J/ψπ⁰ CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine .

Studying the radiative penguin decay process b → sγ, CLEO has measured the branching fraction , and the first and second moments of the B rest frame photon energy spectrum above 2.0 GeV, 〈E_γ〉 = 2.346 ± 0.032 GeV, 〈(E_γ - 〈E_γ〉)²〉 = 0.021 ± 0.007 GeV². In a study of inclusive B semileptonic decay to charm, B → X_cℓν, we find the first and second moments of the hadronic mass-squared distribution, for P_lepton > 1.5 GeV/c, to be , , where is the spin-averaged D, D* mass. Using HQET OPE expressions for the first moments, we find , λ_l = -0.22 ± 0.10 GeV². These in turn, along with a measurement of the semileptonic width in B → X_cℓν, give |V_cb| = 0.0405 ± 0.0015.

We review recent suggestions for testing through B decays the flavor structure of CP violation in the Standard Model. Relative signs of CP asymmetries in U-spin related processes can by themselves test the Kobayashi-Maskawa mechanism in a crude manner. Ratios of charge-averaged decay rates and certain CP asymmetries may constrain tightly the weak phases γ = ɸ₃ and α = ɸ₂.

The CKM phase ɸ₃ = γ may be extracted from the partial rates for CP-tagged B_s decays. Such an experiment could be performed at a very high luminosity symmetric e⁺e^- collider operating at the Υ(5S) resonance, where the state is produced in a state of definite CP. CP-tagging in the B_d system at the Υ(4S), where a time-dependent analysis is required to compensate for the anticipated large CP violation in mixing, is also discussed.

Using 11.1 fb^-1 of data recorded by the Belle detector, we present the preliminary results of our charmonium study. We have measured the branching fractions for the various inclusive and exclusive B decays to charmonium modes. We also present the results on non- charmonium production at Υ(4S).

Direct CP violation in decays such as B^- → D⁰K^- is sensitive to the CKM angle ɸ₃ because these decays allow the interference of b-quark to c-quark with b-quark to u-quark transitions. Indeed, ɸ₃ may be determined if one can infer the strong phase of the B and subsequent D⁰ decays from experimental data. In this talk, I will discuss how this can be carried out using either a single decay mode of the D⁰ by combining data from a number of D⁰ decay modes as well as the use of other, analogous decays and the prospects of implementing such methods at various B-factories. Since the properties of the D⁰ decays are crucial to these methods, it is possible that mixing at the 1% level will contaminate the results. I will therefore discuss various methods to remove such confounding effects so that ɸ₃ may be determined even if such mixing is present.

I review recent results of lattice QCD calculations relevant for B physics. The mass of the bottom quark, the leptonic decay constant and B parameters of B mesons, and form factors for semileptonic decays are presented.

The PEP-II asymmetric e⁺e^- collider has been operating with the BaBar detector for twenty-one months. PEP-II has exceeded its design luminosity reaching 3.3 × 10³³ cm^-2s^-1, has delivered 185 pb^-1 in 24 hours, and has delivered a total integrated luminosity of 27 fb^-1 to BaBar by November 2000.

The performance of KEKB has been improved rapidly in 2001 and the peak luminosity of 3.84 × 10³³cm^-2s^-1 was recorded. The maximum integrated logged luminosity per day and per month by BELLE amounted to 206.7/pb/day and 4.04/fb/month. This increase of the performance is attributed to the suppression of beam blow-up due to photoelectron instabilities by solenoid field imposed on the positron ring vacuum ducts. We reasonably expect that by the end of 2002, BELLE will have logged 100/fb.

A precise measurement of the magnetic anomaly, a = (g - 2)/2, of the positive muon has been made using the Alternating Gradient Synchrotron at Brookhaven Lab. A brief review of the experiment is given, and an analysis of data collected during the 1999 run is detailed. The result a_μ+ = 11 659 202(14)(6) × 10^-10 (1.3 ppm) is in good agreement with the previous world average a_μ = 11 659 205(46) × 10^-10 (3.9 ppm), and the new world average differs by 2.6σ from the standard model prediction a_μ(SM) = 11 659 160(7) × 10^-10 (0.6 ppm), [a_μ(exp) - a_μ(SM)] = 42(16) × 10^-10.

In this paper, we briefly review results on rare decays of B mesons from the Belle experiment, based on 10.4 fb^-1 data collected on the Υ(4S) resonance. The topics include measurements of Cabibbo suppressed decays B → D^(*)K^(*), charmless two-body decays B → ππ, Kπ, KK and , and a search for flavor changing neutral current decays B → K^(*)ℓ⁺ℓ^-.

Preliminary results from the BABAR experiment at the asymmetric B-factory PEP-II at SLAC on charmless B decays into charged pions or kaons, and the measurement of the B→J/ψK* decay amplitudes are presented. The data sample comprises a total number of 22.7 million Υ(4S) decays, corresponding to an integrated on-resonance luminosity of approximately 21 fb^-1. We measure the following CP-averaged branching fractions: , , and an upper limit of , at 90% confidence limit. The measurement of the J/ψK* decay amplitudes results in R_⊥ = 0.160 ± 0.032(stat) ± 0.036(sys), and reveals a dominant longitudinal component. The phase of the longitudinal amplitude shows evidence for non-vanishing final state interaction.

I present an overview of our tests of the Standard Model and searches for non-Standard Model physics with the rare B program at CLEO. I will review our rare B physics analyses, going into further detail for two of our newer analyses, namely measurements of the B → ɸK and B → ɸK* branching fractions and CP asymmetry in b → sγ decays.

We have studied radiative B meson decays using data collected at the Υ(4S) resonance with the Belle detector at the KEKB e⁺ e^- storage ring. We measured the exclusive branching fractions to the K*(892)γ final states to be and . The inclusive branching fraction is measured to be . We searched for B → ργ decays and obtained an upper limit of .

In this talk some of the theoretical aspects of b → sγ transitions are discussed. The focus is on inclusive decays, since these can be computed more reliably. Topics covered are (1) perturbative QCD corrections, (2) non-perturbative contributions and (3) effects of "new physics" in these decays.

Using the data sample of 10.5fb^-1 collected by the Belle detector, we searched for two-body charmless decays involving vector mesons. The clear signal signature of B^± → ɸK^± is seen and its branching fraction is measured to be . The evidence for B^± → ρ⁰π^±, B⁰ → ρ^∓π^± and B^± → ɸK*^± is reported and their branching fractions are determined. No significant signals are observed for , → ɸK*⁰, → ρ^∓ K^±, B^± → ρ⁰ K^±, → ωπ^± and → ωK^± only the 90% C.L. upper limits are given.

Using a data sample of 10.5 fb^-1 collected by the Belle detector, three–body charmless decays B⁺ → k⁺h⁺h^- have been studied. The following branching fractions have been obtained: and . The upper limits for other combinations of charged kaons and pions have been placed. Analysis of the intermediate two-body states gives evidence for production of scalar resonances in charmless B decays.

I review important aspects of the perturbative QCD approach to exclusive B meson decays, concentrating on factorization theorem, gauge invariance, end-point singularities, k_T and threshold resummations, power counting, penguin enhancement, and CP asymmetries.

We study Λ_QCD/m_B corrections to factorization in B → Kπ decays. First, we analyze these decay channels within factorization, showing that, irrespectively of the value of γ, it is not possible to reproduce the experimental data. Then, we discuss Λ_QCD/m_B corrections to these processes, and argue that there is a class of doubly Cabibbo enhanced non-factorizable contributions, usually called charming penguins, that cannot be neglected. Including these corrections, we obtain an excellent agreement with experimental data. Furthermore, contrary to what is obtained with factorization, we predict sizable rate asymmetries in B^± → K^±π⁰ and B → K^±π^∓.

We present preliminary results of several analyses searching for the effects of CP violation and mixing in the decay of D⁰ mesons. We find no evidence of CP asymmetry in five different two-body decay modes of the D⁰ to pairs of light pseudo-scalar mesons: A_CP(K⁺K^-) = (+0.05 ± 2.18 ± 0.84)%, A_CP(π⁺π^-) = (+2.0 ± 3.2 ± 0.8)%, , A_CP(π⁰π⁰) = (+0.1 ± 4.8)%, and . We present the first measurement of the rate of wrong-sign D⁰ → K⁺π^-π⁰ decay: . We also describe a measurement of the mixing parameter by searching for a lifetime difference between the CP neutral K^-π⁺ final state and the CP even K⁺K^- and π⁺π^- final states. Under the assumption that CP is conserved we find y_CP = -0.01l±0.025±0.014. Finally, we present our measurement of the D*⁺ width: 96±4 (stat)±22 (syst) keV.

The lifetimes of charmed mesons have been measured using 11.1 fb^-1 of data collected with the Belle detector at KEKB. Each candidate is fully reconstructed to identify the flavor of the charmed meson. The lifetimes are measured to be τ(D⁰) = (414.5 ± 1.7(stat.)) fs, τ(D⁺) = (1029 ± 12(stat.)) fs and , where the error is statistical only. The ratios of the lifetimes of D⁺ and with respect to D⁰ are measured to be τ(D⁺)/τ(D⁰) = 2.48 ± 0.03(stat.) and . The mixing parameter y_CP is also measured to be through the lifetime difference of D⁰ mesons decaying into CP-mixed states and CP eigenstates. All results are preliminary.

After a short review of the theoretical tools available to describe heavy flavour physics I sketch the present profile of the weak dynamics of charm hadrons with respect to lifetimes, oscillations and CP violation. I argue that comprehensive studies of charm decays provide novel portals to New Physics and suggest some benchmark figures for desirable sensitivities.

Using a sample of 12.2 million τ-lepton pairs produced by e⁺e^- annihilation at and collected by the CLEO detector, we search for and set limits on CP violation in τ-lepton decays. For each event, we require that both τ-leptons decay via the mode τ → ππ⁰ν. The search is performed within the context of a multi-Higgs Doublet Model and the imaginary part of the coupling constant parameterizing the non-Standard Model diagram leading to CP violation is constrained to be at 90% CL. The novel search technique is of general utility.

I discuss the challenges and prospects for measuring B(B → ℓν) and in large data samples taken at the Υ(4S).

Among the several proposed methods for extracting the CP angle ɸ ₃(γ), the first theoretically clean measurement is likely to come from the time-dependent analysis of flavor-tagged decays. A combination of preliminary data analysis of Belle's 6.1fb^-1 and a naive Monte Carlo simulation shows that we can reach the sensitivity δsin(2ɸ ₁ + ɸ₃) = 0.42 when 110fb^-1 is accumulated.

The article summarizes the ideas and motivation of why a e⁺e^- B-factory at the Υ(5S) could be interesting and which quantitative results could be expected. A high-luminosity e⁺e^- collider operated at the Υ(5S) is an abundant source of mesons, produced coherently in form of pairs and in a clean detector environment. A Υ(5S) physics program, eventually to be carried out at BaBar, Belle or CLEO, provides new information on the CKM sector of the Standard Model and direct and unambiguous tests for New Physics. The proposed measurement techniques are presented, the main uncertainties are evaluated and an outlook is given of how a -factory fits into the larger picture of hadroproduction.

The measurement of |V_ub| with accuracy at the level of 5 - 10% is an important part of the B physics program of the next decade. Here I review a variety of methods by which |V_ub| may be extracted. I emphasize those for which theoretical uncertainties may be reduced to this level, and discuss the experimental measurements which will be necessary.

Current methods of determining V_ub are dominated by theoretical uncertainties. We present Monte Carlo simulations of three promising methods of determining V_ub with small theoretical and experimental errors. We find that with data samples of order 1,000 fb^-1 the B factories will attain combined experimental errors of a few % on V_ub, much smaller than the theoretical errors associated with new inclusive methods. Lattice QCD offers the promise of rate calculations of exclusive semileptonic decays with errors of a few %. A data sample of order 10,000 fb^-1, beyond the capabilities of the current B factories, may be required to achieve an experimental error on the exclusive rate comparable to the theoretical error.

Possible scenarios for CKM fits in the years 2005 and 2010 are presented using B- and K-physics results from extrapolated luminosities for B-factories at the Υ(4S), for the hadron machines at Tevatron and LHC and for rare kaon experiments. The study provides an estimate of what precision for the CKM matrix elements can be achieved if all relevant experiments and accelerators, including upgrades for the existing e⁺ e^- machines, reach their design goals. It is intended to give information used to explore which type of future experiments are needed to cover all relevant physics topics related to the CKM matrix and the search of physics beyond the Standard Model.

The performance of silicon-strip vertex detectors, drift chambers, CsI(Tl) electromagnetic calorimeters, and level-1 triggers used in present multipurpose detectors like BABAR is discussed in the context of operations in a high-luminosity environment.

Recent BaBar measurements on lifetime and mixing of B mesons are reported. Various techniques are used, ranging from the full reconstruction of hadronic B decays, to partial reconstruction techniques, and to a totally inclusive approach with dilepton events. The results presented are based on a data sample collected by BaBar during the 1999-2000 data taking, and should be considered as preliminary.

We report measurements of the mixing parameter Δm_d and charged and neutral B_(d) meson lifetimes τ_B+ and τ_B⁰. Data was collected by the Belle detector at the KEKB asymmetric e⁺e^- collider operating at the Υ(4S) resonance. Dilepton events and semileptonic as well as hadronic B meson decays were used. The proper-time difference distributions for same-sign and oppositesign dileptons are simultaneously fitted to an expression containing Δm_d as a free parameter. We obtain Δm_d = 0.463 ± 0.008 (stat.) ± 0.016 (sys.) ps^-1. Semileptonic B meson decays are reconstructed via the modes; B → D*lν, yielding measured lifetimes of τ_B⁰ = 1.518±0.045(stat.) ps and τ_B^- = 1.628±0.060(stat.) ps. Flavour tagging the other neutral B meson and fitting to the oppositeflavour and same-flavour proper-time distributions with Δm_d as a free parameter yields the result Δm_d = 0.522 ± 0.026 (stat.) ps_-1. Hadronic B meson decays are reconstructed via the modes; B⁰ → D*^-π⁺, D*^-ρ⁺, D^-π⁺ and B^- → D⁰π^-. The lifetimes are measured to be: and . Again, by flavour tagging the other neutral B meson and fitting to the proper-time distributions we obtain: Δm_d = 0.527 ± 0.032 (stat.) ps^-1

The contribution of the LEP experiments and SLD to B physics is reviewed. The selected topics are lifetimes, the semileptonic branching ratio, CKM elements V_cb and V_ub, and oscillation. Finally the constraints on the CKM matrix are discussed.

The current status of the experimental knowledge of B_s meson physics is reviewed. Results from LEP and CDF on the width difference ΔΓ_s are presented, the corresponding average is found to be in good agreement with the present theoretical estimation. The B_s oscillations have not yet been resolved, despite the progress recently achieved by SLD and ALEPH. The world combination, including results from the LEP experiments, SLD and CDF, is presented, together with the expected and observed lower limit on the B_s oscillation frequency. A tantalizing hint of an oscillation is observed around Δm_s ~ 17 ps^-1, near future results could increase the significance of this hint.

We extend our previous studies to calculate the B meson B parameters B_B and B_S on the lattice, and present an update of the results for the B_s meson width difference. We perform an extensive study of systematic errors in the quenched calculation of the B-parameters, and find that the systematic errors are in good control using the NRQCD action for heavy quark. We also report our preliminary results from unquenched simulations.

Supersymmetry exhibts new sources of CP violation. We discuss the implications of these new contributions to CP violation both in the K and B physics. We show that CP violation puts severe constraints on low energy SUSY, but it represents also a promising ground to look for signals of new physics.

We show how B → ππ decays can be used to search for new physics in the b → d flavour-changing neutral current. One needs one piece of theoretical input, which we take to be a prediction for P/T, the ratio of the penguin and tree amplitudes in . If present, new physics can be detected over most of the parameter space. If α (ɸ₂) can be obtained independently, measurements of B⁺ → π⁺π⁰ and are not even needed.

We have entered the era of BaBar, Belle and Tevatron competition; with new hardware and unprecedented statistics reach, we must be prepared for discovering new phenomena. While these unfoldings could be coming from new physics, it could also come about as new tricks from old. We illustrate new physics with generic bsg dipole and its impact on sin 2Φ_ɸKS, and at a deeper level, the marriage of flavor symmetries and SUSY, which could impact on B_d, B_s and D⁰ mixings and CP violation, and possibility of a light squark. As simple unfolding, we touch upon charmless B → baryonic pair decay, with or without an associated η′/γ. We close with the possible spectacular signal of B → J/ΨDπ as a flabbergasting new trick from nonperturbative QCD: intrinsic charm of B.

I report two results from the CLEO collaboration using semileptonic B meson decays. The first measurement uses charge asymmetries in like-sign dilepton events at the Υ(4S) to search for CP violation in mixing. Our result ℜe(∈_B)/(1 + |∈_B|²) = 0.0035 ± 0.0103 ± 0.0015 using 10 million events is competitive with LEP measurements and statistically limited. The second result is a preliminary measurement of the CKM matrix element |V_cb| using . We study the decay rate as a function of w = u_B · u_D*. By extrapolating to w = 1, we extract the product , where the form factor is predicted accurately by theory. We find . We also integrate the differential decay rate over w to obtain . In conclusion I make a comparison to other |V_cb| determinations.

We have studied inclusive and exclusive semileptonic decays to obtain the CKM matrix elements |V_cb| and |V_ub| using 11 fb^-1 of e⁺e^- collision data sample recorded with the Belle detector at KEKB. We determine the inclusive semileptonic branching fraction using a di-lepton analysis and find that |V_cb|F_D* (1) = (3.57 ± 0.11 ± 0.13) × 10^-2 from , |V_cb|F_D(1) = (4.42 ± 0.48 ± 0.35) × 10^-2 from . An upper limit of |V_cb| < 0.009 is estimated from mode. Charge-conjugate modes are implied throughout this paper.

We undertake a critical appraisal of the existing experimental and theoretical inputs used to deduce constraints on sin 2β and other important parameters and thus find, in particular, sin2β > 0.50 at 95% CL which is completely compatible with the combined experimental result: sin2β = 0.46 ± 0.17, representing an important success of the CKM model of CP violation. Searches for new physics in B decays to ψ + K⁰ like final states will require improved precision; we make some suggestions to facilitate these. The experimental result already tend to disfavor new physics scenarios with CKM phase = 0. We also present a global fit including the new CP asymmetry measurements in B → ψ + K⁰ as an additional input yielding e.g. γ = (29° → 56°), , , J_CP = (1.8 → 3.0) × 10^-5, and at 95% CL.

We present a preliminary measurement by KTeV of the charge asymmetry δ_L in the mode K_L → π^±e^∓ν based on nearly 300 million analyzed decays. The measurement is a substantial improvement on the current world average. We measure a value of δ_L = 3320 ± 58(stat) ± 46(sys) ppm, which is in good agreement with the previous measurements. The result is used to place more stringent limits on CPT and ΔS = ΔQ violation in the neutral kaon system.

The KTeV experiment at Fermilab collected data on rare K_L decays during runs in 1997 and 1999 with a total flux of 6 × 10¹¹ K_L decays. Here we present recent results from this work. In the decay K_L → π⁺π^-e⁺e^- a new indirect CP-violating effect has been seen as an asymmetry in the decay angular distribution. Further analysis of this mode leads to a precise measurement of the K_L charge radius. The first upper limit on the branching fraction of the decay K_L → π⁰π⁰e⁺e^- is presented. Order of magnitude improvements in upper limits on the branching ratios of K_L decays to π⁰e⁺e^-, π⁰μ⁺μ^-, and have been achieved. These decays are expected to result partially or entirely from direct CP violations and their rates may be sensitive to physics beyond the standard model.

Recently two proposals of the NA48 collaboration to extend its physics program after the completion of the ∈′/∈ measurement have been approved. The first will address several topics in rare hyperon and K_S decays, using an high intensity K_S beam. A running period of about 120 days in 2002 is planned. In the second extension the focus is on the measurement of direct CP violation in charged kaon decay, using simultaneous K^± beams. It is foreseen to start in 2003 and to continue until 2004 with two running periods of about 120 days each.

The Tevatron begins Run II on March 1, 2001, generating interactions at a collision energy of . With an instantaneous luminosity of 2 × 10³² cm^-2s^-1, the Tevatron promises to deliver 2 fb^-1 to the CDF and DØ detectors in the first two years of running. Both detectors have been upgraded to take full advantage of the higher luminosity conditions. Now the CDF and DØ collaborations are preparing to perform several B physics studies in Run II. We describe several of the studies aimed towards constraining the CKM matrix and understanding CP violation, namely, the unitarity angles α, β and γ, and the B_s mixing parameters.

BTeV¹ is a recently approved collider program at the Fermilab Tevatron dedicated to the study of CP violation, mixing and rare decays of beauty and charm hadrons. The suitability of the proposed BTeV detector to measure the weak angle α via the time resolved Dalitz analysis of the decay B → ρπ is discussed. A comparison of BTeV to contemporary experiments in the LHC era is also shown.

CP violation is one of the few remaining open questions in the Standard Model. Although there is increasing evidence that CP violation phenomena can be well accommodated in the framework of the Standard Model, it is not excluded that there exists a sizable contribution from new physics, or even that CP violation is entirely due to new physics. A better insight into this problem can be obtained by studying CP violation in B-meson decays in detail. The ultimate opportunity of doing such studies is offered by LHC, in particular with the LHCb detector which is designed for this purpose.

A new contribution from pair-production of light gluinos, of mass 12 to 16 GeV, with two-body decays into bottom quarks and light bottom squarks, helps to obtain a bottom-quark production rate in better agreement with hadron collider data. The masses of the gluino and bottom squark are further restricted by the ratio of like-sign to opposite-sign leptons at hadron colliders. Constraints on this scenario from other data are examined and predictions are made.

Hadron models and QCD are needed to interpret B decay data to hadrononic final states. Peculiar systematics may provide clues to new physics as well as to inadequacies in hadron models. Simple experimental tests are proposed to clarify the origin for the anomalously high η′ appearance in charmless strange final states in B decays. Implications are discussed for the large branching ratios observed for decays to final states containing the a₁ (1260)^± which suggest a "vector-dominance model" in which a W is produced and immediately turns into an axial vector, vector or pseudoscalar meson. The model predicts branching ratios of the order of 1% for the as yet unobserved B decays into states containing the D_sl(2536) charmed-strange axial vector meson. Decays to mixtures of radially excited states are also considered.

Exclusive B decays can be factorized as convolutions of hard scattering amplitudes involving the weak interaction with universal hadron distribution amplitudes, thus providing a new QCD-based phenomenology. In addition, semi-leptonic decay amplitudes can be computed exactly in terms of the diagonal and off-diagonal Δn = 2 overlap of hadronic light-cone wavefunctions. I review these formalisms and the essential QCD ingredients. A canonical form of the light-cone wavefunctions, valid at low values of the transverse momenta, is presented. The existence of intrinsic charm Fock states in the B meson wavefunction can enhance the production of final states of B-decay with three charmed quarks, such as B → J/ψDπ, as well as lead to the breakdown of the CKM hierarchy.

Recent progress in understanding the physics of B mesons and of CP violation, as presented to this Workshop, is put in historical perspective and summarized.

We suggest a possible supersymmetric CP violation mechanism through the gluino-squark loop effect. The new contribution can by itself explain both ∈_K and Re(∈′/∈_K) of the kaon system, or can compete with their standard model contributions. We realize this idea in two popular squark mass patterns: universality and effective SUSY, and show that the neutron electric dipole moment constraint can be safely evaded. Influences on rare kaon decay modes are also investigated as potential discriminants of our scenario from the standard model.

We discuss an improved theoretical description of the semi-inclusive B meson decays B → K(K*)X. The decay distributions are calculated. Their branching ratios are found to be appreciable. The CP asymmetries in the neutral B modes are sizable. An observation of direct CP violation and a measurement of γ may come from these neutral B modes.

We investigate decay based on perturbative QCD approach which has recently been applied to B meson decays. decay can be one of the hopeful modes to determine |V_ub| since it occurs through b → n transition only. We estimate both factorizable and non-factorizable contribution, and show that non-factorizable contribution is much less than factorizable one. Our calculation gives .

We describe a new method for extracting weak, CP-violating phase information, with no hadronic uncertainties, from an angular analysis of B → V₁V₂ decays, where V₁ and V₂ are vector mesons. The quantity sin²(2ɸ₁ + ɸ₃) can be obtained cleanly from the study of decays such as , etc. Similarly, one can use or even to extract sin²ɸ₃. There are no penguin contributions to these decays. It is possible that sin²(2ɸ₁ + ɸ₃) will be the second function of CP phases, after sin 2ɸ₁, to be measured at B-factories.

We propose a new method to extract the CP violating weak phase γ in the CKM paradigm of the Standard Model, using B^- → D⁰π^- → fπ^- and decays, where f are final states such as K⁺π^-, K⁺ρ^-, Kππ, etc. We also study the experimental feasibility of our new method. With possibility of new phases in the CKM matrix, we re-examine some of the previously proposed methods to determine γ, and find that it would be in principle possible to identify γ and a new phase angle θ separately.

We investigate the effect of supersymmetric CP violating phases on the inclusive decay B → X_dγ. Although such a decay contains a large background from B → X_sγ, if isolated it may exhibit sizeable CP violation, both in the Standard Model (SM) and in the context of models beyond the SM. With unconstrained supersymmetric CP violating phases we show that the direct CP asymmetry () lies in the region , where a positive asymmetry would constitute a clear signal of physics beyond the SM. Even if a direct measurement of B → X_dγ proves too difficult experimentally, its asymmetry contributes non-negligibly to the measurements of for B → X_sγ, and thus should be included in future analyses. We show that there may be both constructive and destructive interference between and .

We present our study on B →πlν semileptonic decay form factors with lattice QCD near zero recoil using NRQCD action for the heavy quark. From a quenched lattice QCD simulation at β=5.9 on a 16 ³ × 48 lattice, we obtain the form factors f₁ (v · k_π) and f₂(v · k_π) in the heavy quark effective theory by Burdman et al.. We find that that l/m _B dependence of the form factors are small. The limit of physical heavy and light quark masses can be reached without introducing any model function, and we obtain a prediction for the differential decay rate dΓ/dq ².

The significance of the sin 2ɸ₁ measurements are considered using Bayesian and frequentist analysis based on the paper of Feldman and Cousins¹. The merits and meaning of these methods are compared. Consistency of the result with the CKM model is considered as well as the significance of the CP violating signal. The statistical analysis is applied first to the Belle measurement and then to the World measurements on the last page. The individual measurements are combined in an unofficial World average of sin 2ɸ₁ = 0.48 ± 0.l6.

We report on a new approach to a global CKM matrix analysis taking into account most recent experimental and theoretical results, in particular, the new sin2β measurements from the B factories. The statistical framework developed advocates formal frequentist statistics. We emphasize the distinction of a model testing and a model dependent, metrological phase in which the various parameters of the theory are determined. Graphical results for confidence levels are drawn in various one and two-dimensional parameter spaces. Numerical results are obtained for all relevant parameters of the theory and predictions for branching ratios of rare K and B meson decays are given.

We analyze the , , B^- → ρ⁰K^-, B^- → ρ^-K⁰, , and B^- → ωK^- decays (including CP conjugate modes) with the modified factorization theorem. Based upon the PQCD, we find that the dominant contributions arise from the absorptive parts of annihilation topologies. Using accessible values of various parameters we obtain that , Br(B^- → ρ⁰K^-) = (3.50 ~ 4.66) × 10^-6, and Br(B^- → ω K^-) = (4.52 ~ 6.25) × 10^-6, and the corresponding CP asymmetries are over 50% with ɸ3(γ) = 0.4π. However, for the averaged CP conjugate mode, we have that Br(B → ρ⁰K⁰) = (1.60 ~ 3.00) × 10^-6, Br(B^± → ρ^±K⁰) = (1.92 ~ 3.44) × 10^-6, and Br(B → ωK⁰) = (1.55 ~ 2.42) × 10^-6, and the associated CP asymmetries are only a few percent.

The rare decays and can occur only through annihilation type diagrams in the standard model. We calculate these decays in a perturbative QCD approach. We find that the branching ratio of is around 10^-5 – 10^-4 which is close to the upper limit by the experiments. On the other hand, the branching ratio of is of order 10^-8 which is very small due to the suppression from CKM matrix elements .

We have searched for CP/T violations in reactions with τ leptons at Belle using CP-odd 3-momentum correlations in ∈⁺∈^- → τ⁺ τ^- and decay angular distributions in τ^± → π^±π⁰ν. Preliminary results indicate that CP/T invariance is valid to an accuracy of 1%.

We report a search for the lepton flavor violating decay τ → ℓ K⁰. (ℓ = e, μ) This is based on 9.8 fb^-1 data sample around the Υ(4S) resonance energy with Belle detector at KEKB asymmetric e⁺e^- collider. No event is observed both of the modes from this data sample. We set new upper limits of 4.9 × 10^-6 and 4.6 × 10^-6 at 90% C.L. for the branching ratios of τ → eK⁰ and μK⁰ respectively.

We summarize the present status of heavy-hadron lifetimes focusing mainly on heavy-baryon lifetimes.

We report the first observation of the exclusive decay process B → J/ψK₁(1270) using a sample of 11.1M meson pairs collected in the Belle detector at the KEKB asymmetric energy e⁺e^- collider. We measure branching fractions of and , where the first error is statistical and the second is systematic. These modes constitute approximately 15% of the total number of B → J/ψX decays. No evidence is seen for B → J/ψK₁(1400) and we set an upper limit of this branching fraction. The K₁(1270) → K⁰π⁺π^- decays have a substantial K⁰ρ⁰ intermediate state component that may be useful for CP violation studies.

We report on lattice calculations of the B meson decay constant and the B-parameters using the NRQCD action for heavy quark. We performed a set of calculations at three lattice spacings in the quenched approximation in order to investigate the systematic uncertainty associated with the lattice discretization. Our results indicate that the systematic error is under good control for f_B and B_B. We also present preliminary results from our unquenched simulation.

We analyze the spacetime structure of the Feynman diagrams for charmless B decays. This enables us to classify the power corrections. After showing the factorization of the twist 3 short distance contributions from the related long distance contributions for each Feynman diagram, we can separate the next to leading twist contributions from the leading twist ones.

In this paper, we discuss physics potential of the Very Long Base-Line (VLBL) Neutrino-Oscillation Experiments with the High Intensity Proton Accelerator (HIPA), which is planned to be built by 2006 in Tokaimura, Japan. We propose to use conventional narrow-band ν_μ beams (NBB) from HIPA for observing the ν_μ → ν_e transition probability and the ν_μ survival probability. The pulsed NBB allows us to obtain useful information through counting experiments at a huge water-Cherenkov detector which may be placed our neighbor countries. We study sensitivity of such experiment to the neutrino mass hierarchy, the mass-squared differences, the mixing angles and the CP phase of the 3 × 3 lepton flavor mixing matrix (MNS matrix). The CP phase can be measured with a 100kt detector if both the mass-squared difference and U_e3 elements of the MNS matrix are sufficiently large.

The R-parity-violating interactions within their current experimental upper bounds can trigger large mixing-induced CP asymmetry in exclusive radiative B decays that may be detectable in the upcoming B factories.

We compute B → Kη^(′) branching ratio using perturbative QCD (pQCD) approach. After including SU(3) breaking effects and also color suppressed penguin contributions, we have obtained Br(B⁰ → K⁰η′) = 18 × 10^-6 which is still small compared to the experimental value.

In the framework of Abelian horizontal symmetries, large strange-beauty mixing appears naturally in the right-handed sector. Adding SUSY, one in general would have a light strange-beauty squark that carries both strange and beauty flavor. Other squarks, gluinos and charginos are all at TeV scale when the constraints from and mixing are taken into account, but the neutralino may be light without violating the b → sγ constraint. mixing could be at present experimental limit or higher, but would in general carry a CP violating phase. Collider signatures of the strange beauty squark differ from standard bottom squarks with relative abundance of strange quarks in the final state.

Radiative B decay is studied in the framework of perturbative QCD approach. The short distance (SD) contribution is computed by using B and D* wave function which is consistent with heavy quark symmetry and valence quark picture. The branching ratio is predicted and it is as small as 10^-8. In addition to color suppression and helicity suppression due to charm quark mass, it is suppressed by Sudakov factor.

The radiative decay B → X_sγ and the mixing are discussed in the vector-like quark model which contains extra SU(2)-singlet quarks with the same electric charges as the up-type and down-type quarks. Constraints on the extended Cabibbo-Kobayashi-Maskawa matrix are obtained from the experimental results for the branching ratio of B → X_sγ. Within these experimental bounds, any value of the branching ratio can be accounted for by the contributions from the vector-like quarks. In sizable ranges of the model parameters, the mixing parameter for is much different from the prediction of the standard model.

We consider the decays of B mesons to two vector mesons (B → VV) in a perturbative QCD approach. In this approach we include certain nonfactorizable contributions in addition to the usual factorizable ones. We calculate the helicity amplitudes for B → D*^±ρ^∓, and compare our results with experiments. We show that experimental data requires that non leading higher twist contributions be included. We treat D* meson in the heavy quark limit and include twist-3 contributions to the ρ meson wavefunction. We also consider color suppressed mode B → J/ψK*.

We write down some relevant matrix element for the scattering and decay processes of the pion by considering a quark-meson vertex function. The pion charge and transition form factors F_π, F_πγ, and F_πγ* are extracted from these matrix elements using a relativistic quark model on the light-front. We find that, on the one hand, the form factors F_π and F_πγ in the space-like region agree well with experiment; on the other hand, the branching ratios of all observed decay modes of the neutral pion, that are related to the form factors F_πγ and F_πγ* in the time-like region, are all consistent with the data as well.

Recent results from Belle and BaBar Collaborations hint at a small sin 2ɸ₁, and the measured B → ππ rate also seems to be on the low side. Supersymmetry (SUSY) models with down squark mixings can account for the deficits in both cases. By studying the origin of SUSY contributions that could impact on mixing and on B → ππ decay, we find that the former would most, likely be due to left-left or right-right, squark mixings, while the latter would come from left-right, squark mixings. These two processes in general are not much correlated in the Minimum Supersymmetric Standard Model. If the smallness of B → ππ is due to SUSY models, one would likely have large B → ργ from chiral enhancement, and the rate could be within present, experimental reach. Even if B → ργ is not greatly enhanced, it could have large mixing dependent CP violation through SUSY.

The production of a kaon pair (K⁺K^- and ) in two-photon processes has been measured using the Belle detector at the electron-positron collider KEKB. We have obtained the invariant-mass distribution of the processes between 1.3 and 2.3 GeV. A broad bump structure around 1.7 GeV in the channel is confirmed, while, in the K⁺K^- channel, a bump structure is seen near 1.9 GeV. The angular distribution of the final-state kaons is analyzed to explore the spin(-helicity) structure in each invariant-mass region for the two processes. Contributions from existing and postulated resonances are discussed.

LHCb is a hadron collider experiment in preparation at CERN, which plans to start taking data at its full potential as soon as the LHC machine becomes operational. It is dedicated to the study of CP violation and other rare phenomena with b hadrons produced copiously in the forward region. The design and realization of an efficient and selective trigger for both fully-hadronic and leptonic B decays in specific channels of interest is one of the major challenges of the experiment. Following a description of the LHCb detector and its environment at LHC, the current design of the trigger scheme is presented and its expected performance is discussed.

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