skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Determination of {gamma} from charmless B{yields}M{sub 1}M{sub 2} decays using U-spin

Abstract

In our previous paper we applied U-spin symmetry to charmless hadronic B{sup {+-}}{yields}M{sup 0}M{sup {+-}} decays for the purpose of precise extraction of the unitarity angle {gamma}. In this paper we extend our approach to neutral B{sup 0} and B{sub s}{yields}M{sub 1}M{sub 2} decays. A very important feature of this method is that no assumptions regarding relative sizes of topological decay amplitudes need to be made. As a result, this method avoids an uncontrollable theoretical uncertainty that is often related to the neglect of some topological diagrams (e.g., exchange and annihilation graphs) in quark-diagrammatic approaches. In charged B{sup {+-}} decays, each of the four data sets, P{sup 0}P{sup {+-}}, P{sup 0}V{sup {+-}}, V{sup 0}P{sup {+-}} and V{sup 0}V{sup {+-}}, with P{identical_to}pseudoscalar and V{identical_to}vector, can be used to obtain a value of {gamma}. Among neutral decays, only experimental data in the B{sup 0}, B{sub s}{yields}P{sup -}P{sup +} subsector is sufficient for a U-spin fit. Application of the U-spin approach to the current charged and neutral B decay data yields: {gamma}=(80{sub -8}{sup +6}) deg. In this method, which is completely data driven, in a few years we should be able to obtain a model-independent determination of {gamma} with an accuracy of O(fewmore » degrees)« less

Authors:
;  [1]
  1. High Energy Theory Group, Brookhaven National Laboratory, Upton, New York 11973 (United States)
Publication Date:
OSTI Identifier:
21020053
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevD.75.054006; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANNIHILATION; B MINUS MESONS; B NEUTRAL MESONS; B PLUS MESONS; B S MESONS; DECAY AMPLITUDES; FEYNMAN DIAGRAM; PARTICLE DECAY; PSEUDOSCALAR MESONS; QUARKS; SPIN; SYMMETRY; TOPOLOGY; UNITARITY; VECTOR MESONS

Citation Formats

Soni, Amarjit, and Suprun, Denis A. Determination of {gamma} from charmless B{yields}M{sub 1}M{sub 2} decays using U-spin. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.054006.
Soni, Amarjit, & Suprun, Denis A. Determination of {gamma} from charmless B{yields}M{sub 1}M{sub 2} decays using U-spin. United States. doi:10.1103/PHYSREVD.75.054006.
Soni, Amarjit, and Suprun, Denis A. Thu . "Determination of {gamma} from charmless B{yields}M{sub 1}M{sub 2} decays using U-spin". United States. doi:10.1103/PHYSREVD.75.054006.
@article{osti_21020053,
title = {Determination of {gamma} from charmless B{yields}M{sub 1}M{sub 2} decays using U-spin},
author = {Soni, Amarjit and Suprun, Denis A.},
abstractNote = {In our previous paper we applied U-spin symmetry to charmless hadronic B{sup {+-}}{yields}M{sup 0}M{sup {+-}} decays for the purpose of precise extraction of the unitarity angle {gamma}. In this paper we extend our approach to neutral B{sup 0} and B{sub s}{yields}M{sub 1}M{sub 2} decays. A very important feature of this method is that no assumptions regarding relative sizes of topological decay amplitudes need to be made. As a result, this method avoids an uncontrollable theoretical uncertainty that is often related to the neglect of some topological diagrams (e.g., exchange and annihilation graphs) in quark-diagrammatic approaches. In charged B{sup {+-}} decays, each of the four data sets, P{sup 0}P{sup {+-}}, P{sup 0}V{sup {+-}}, V{sup 0}P{sup {+-}} and V{sup 0}V{sup {+-}}, with P{identical_to}pseudoscalar and V{identical_to}vector, can be used to obtain a value of {gamma}. Among neutral decays, only experimental data in the B{sup 0}, B{sub s}{yields}P{sup -}P{sup +} subsector is sufficient for a U-spin fit. Application of the U-spin approach to the current charged and neutral B decay data yields: {gamma}=(80{sub -8}{sup +6}) deg. In this method, which is completely data driven, in a few years we should be able to obtain a model-independent determination of {gamma} with an accuracy of O(few degrees)},
doi = {10.1103/PHYSREVD.75.054006},
journal = {Physical Review. D, Particles Fields},
number = 5,
volume = 75,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • The decays of B mesons to a pair of charmless pseudoscalar mesons (PP decays) have been analyzed within the framework of flavor SU(3) symmetry and quark-diagrammatic topological approach. Flavor symmetry breaking is taken into account in tree (T) amplitudes through ratios of decay constants fK and f{pi}; exact SU(3) is assumed elsewhere. Acceptable fits to B {yields} PP branching ratios and CP asymmetries are obtained with tree, color-suppressed and QCD penguin amplitudes. Singlet penguin amplitude was introduced to describe decay amplitudes of the modes with {eta} and {eta}' mesons in the final state. Electroweak penguin amplitudes were expressed in termsmore » of the corresponding tree-level diagrams. Values of the weak phase {gamma} were found to be consistent with the current indirect bounds from other analyses of CKM parameters.« less
  • Using the previous Belle measurement of the inclusive photon energy in B{yields}X{sub s}{gamma} decays, we determine the first and second moments of this spectrum for minimum photon energies in the B meson rest frame ranging from 1.8 to 2.3 GeV. Combining these measurements with recent Belle data on the lepton energy and hadronic mass moments in B{yields}X{sub c}l{nu} decays, we perform fits to theoretical expressions derived in the 1S and kinetic mass schemes and extract the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element V{sub cb}, the b-quark mass, and other nonperturbative parameters. In the 1S scheme analysis we find |V{sub cb}|=(41.56{+-}0.68(fit){+-}0.08({tau}{submore » B}))x10{sup -3} and m{sub b}{sup 1S}=(4.723{+-}0.055) GeV. In the kinetic scheme, we obtain |V{sub cb}|=(41.58{+-}0.69(fit){+-}0.08({tau}{sub B}){+-}0.58(th))x10{sup -3} and m{sub b}{sup kin}=(4.543{+-}0.075) GeV.« less
  • We study the final-state interaction (FSI) effects in charmless B{sub u,d,s}{yields}PP decays. We consider a FSI approach with both short- and long-distance contributions, where the former are from inelastic channels and are contained in factorization amplitudes, while the latter are from the residual rescattering among PP states. Flavor SU(3) symmetry is used to constrain the residual rescattering S matrix. We fit to all available data on the CP-averaged decay rates and CP asymmetries, and make predictions on unmeasured ones. We investigate the K{pi} direct CP violations that lead to the so-called K{pi} puzzle in CP violation. Our main results aremore » as follows: (i) Results are in agreement with data in the presence of FSI. (ii) For B decays, the {pi}{sup +}{pi}{sup -} and {pi}{sup 0}{pi}{sup 0} rates are suppressed and enhanced, respectively, by FSI. (iii) The FSI has a large impact on direct CP asymmetries (A) of many modes. (iv) The deviation ({delta}A) between A(B{sup 0}{yields}K{sup -}{pi}{sup +}) and A(B{sup -}{yields}K{sup -}{pi}{sup 0}) can be understood in the FSI approach. Since A(K{sup -}{pi}{sup 0}) is more sensitive to the residual rescattering, the degeneracy of these two direct CP violations can be successfully lifted. (v) Sizable and complex color-suppressed tree amplitudes, which are crucial for the large {pi}{sup 0}{pi}{sup 0} rate and {delta}A, are generated through exchange rescattering. The correlation of the ratio B({pi}{sup 0}{pi}{sup 0})/B({pi}{sup +}{pi}{sup -}) and {delta}A is studied. (vi) The B{sup -}{yields}{pi}{sup -}{pi}{sup 0} direct CP violation is very small and is not affected by FSI. (vii) Several B{sub s} decay rates are enhanced. In particular, the {eta}{sup '}{eta}{sup '} branching ratio is enhanced to the level of 1.0x10{sup -4}, which can be checked experimentally. (viii) Time-dependent CP asymmetries S in B{sub d,s} decays are studied. The {delta}S(B{sup 0}{yields}K{sub S}{eta}{sup '}) is very small ({<=}1%). This asymmetry remains to be one of the cleanest measurements to search for new physics phases. The asymmetry S from B{sub s} to PP states with strangeness S=+1 are expected to be small. We found that the |S| for B{sub s}{sup 0}{yields}{eta}{eta}, {eta}{eta}{sup '}, and {eta}{sup '}{eta}{sup '} decays are all below 0.06. CP asymmetries in these modes will be useful to test the SM.« less
  • We study the charmless decays B{yields}K{sub h{eta}} and B{yields}K{sub h{eta}}{sup '} within the framework of QCD factorization (QCDF) for K{sub h}=K, K{sup *}, K{sub 0}{sup *}(1430) and naive factorization for K{sub h}=K{sub 2}{sup *}(1430). There are three distinct types of penguin contributions: (i) b{yields}sqq{yields}s{eta}{sub q}, (ii) b{yields}sss{yields}s{eta}{sub s}, and (iii) b{yields}sqq{yields}qK{sub h}, where {eta}{sub q}=(uu+dd)/{radical}(2) and {eta}{sub s}=ss. B{yields}K{sup (*){eta}(')} decays are dominated by type-II and type-III penguin contributions. The interference, constructive for K{eta}{sup '} and K{sup *{eta}} and destructive for K{eta} and K{sup *{eta}'}, between type-II and type-III diagrams explains the pattern of {Gamma}(B{yields}K{eta}{sup '})>>{Gamma}(B{yields}K{eta}) and {Gamma}(B{yields}K{sup *{eta}'})<<{Gamma}(B{yields}K{sup *{eta}}).more » Within QCDF, the observed large rate of the K{eta}{sup '} mode can be naturally explained without invoking flavor-singlet contributions or something exotic. The decay pattern for B{yields}K{sub 0}{sup *}(1430){eta}{sup (')} decays depends on whether the scalar meson K{sub 0}{sup *}(1430) is an excited state of {kappa} or a lowest-lying P-wave qq state. Hence, the experimental measurements of B{yields}K{sub 0}{sup *}(1430){eta}{sup (')} can be used to explore the quark structure of K{sub 0}{sup *}(1430). If K{sub 0}{sup *}(1430) is a low-lying qq bound state, we find that K{sub 0}{sup *{eta}} has a rate slightly larger than K{sub 0}{sup *{eta}'} owing to the fact that the {eta}-{eta}{sup '} mixing angle in the {eta}{sub q}, {eta}{sub s} flavor basis is less than 45 degree sign , in agreement with experiment. The type-III penguin diagram does not contribute to B{yields}K{sub 2}{sup *{eta}(')} under the factorization hypothesis and the type-II diagram dominates. The ratio {Gamma}(B{yields}K{sub 2}{sup *{eta}'})/{Gamma}(B{yields}K{sub 2}{sup *{eta}}) is expected to be of order 2.5 as a consequence of (i) |f{sub {eta}}{sup 's}|>|f{sub {eta}}{sup s}| and (ii) a destructive (constructive) interference between type-I and type-II penguin diagrams for K{sub 2}{sup *{eta}} (K{sub 2}{sup *{eta}'}). However, the predicted rates of B{yields}K{sub 2}{sup *{eta}(')} in naive factorization are too small by 1 order of magnitude and this issue remains to be resolved. There are two K{sup (*){eta}(')} modes in which direct CP asymmetries have been measured with significance around 4{sigma}: A{sub CP}(K{sup -}{eta})=-0.37{+-}0.09 and A{sub CP}(K{sup *0}{eta})=0.19{+-}0.05. In QCDF, power corrections from penguin annihilation which are needed to resolve CP puzzles in K{sup -}{pi}{sup +} and {pi}{sup +}{pi}{sup -} modes will flip A{sub CP}(K{sup -}{eta}) into a wrong sign. We show that soft corrections to the color-suppressed tree amplitude a{sub 2} in conjunction with the charm content of the {eta} will finally lead to A{sub CP}(K{sup -}{eta})=-0.15{sub -0.28}{sup +0.19}. Likewise, this power correction is needed to improve the prediction for A{sub CP}(K{sup *0{eta}}).« less
  • We report measurements of the branching fractions of neutral and charged B meson decays to final states containing a K{sub 1}(1270) or K{sub 1}(1400) meson and a charged pion. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, correspond to 454x10{sup 6} BB pairs produced in e{sup +}e{sup -} annihilation. We measure the branching fractions B(B{sup 0{yields}}K{sub 1}(1270){sup +{pi}-}+K{sub 1}(1400){sup +{pi}-})=3.1{sub -0.7}{sup +0.8}x10{sup -5} and B(B{sup +{yields}}K{sub 1}(1270){sup 0{pi}+}+K{sub 1}(1400){sup 0{pi}+})=2.9{sub -1.7}{sup +2.9}x10{sup -5} (<8.2x10{sup -5} at 90% confidence level), where the errors are statistical and systematic combined. The B{sup 0} decay mode is observed withmore » a significance of 7.5{sigma}, while a significance of 3.2{sigma} is obtained for the B{sup +} decay mode. Based on these results, we estimate the weak phase {alpha}=(79{+-}7{+-}11) deg. from the time-dependent CP asymmetries in B{sup 0{yields}}a{sub 1}(1260){sup {+-}{pi}{+-}}decays.« less