a r X i v :0802.2268v 1 [h e p -e x ] 15 F e
b 2008
CLNS 07/2014CLEO 07-18
Determination of the D 0→K +π?Relative Strong Phase Using
Quantum-Correlated Measurements in e +e ?→D 0ˉD
0at CLEO D.M.Asner,1K.W.Edwards,1P.Naik,1R.A.Briere,2T.Ferguson,2G.Tatishvili,2
H.Vogel,2M.E.Watkins,2J.L.Rosner,3J.P.Alexander,4D.G.Cassel,4J.E.Duboscq,4R.Ehrlich,4L.Fields,4L.Gibbons,4R.Gray,4S.W.Gray,4D.L.Hartill,4B.K.Heltsley,4D.Hertz,4C.D.Jones,4J.Kandaswamy,4
D.L.Kreinick,4V.
E.Kuznetsov,4H.Mahlke-Kr¨u ger,4D.Mohapatra,4P.U.E.Onyisi,4
J.R.Patterson,4D.Peterson,4D.Riley,4A.Ryd,4A.J.Sado?,4X.Shi,4S.Stroiney,4W.M.Sun,4T.Wilksen,4S.B.Athar,5R.Patel,5J.Yelton,5P.Rubin,6B.I.Eisenstein,7I.Karliner,7S.Mehrabyan,7N.Lowrey,7M.Selen,7E.J.White,7J.Wiss,7R.E.Mitchell,8M.R.Shepherd,8D.Besson,9T.K.Pedlar,10D.Cronin-Hennessy,11K.Y.Gao,11J.Hietala,11Y.Kubota,11T.Klein,https://www.doczj.com/doc/f91183233.html,ng,11
R.Poling,11A.W.Scott,11P.Zweber,11S.Dobbs,12Z.Metreveli,12K.K.Seth,12
A.Tomaradze,12J.Libby,13A.Powell,13G.Wilkinson,13K.M.Ecklund,14W.Love,15V.Savinov,15A.Lopez,16H.Mendez,16J.Ramirez,16J.Y.Ge,17
https://www.doczj.com/doc/f91183233.html,ler,17B.Sanghi,17I.P.J.Shipsey,17B.Xin,17G.S.Adams,18M.Anderson,18
J.P.Cummings,18I.Danko,18D.Hu,18B.Moziak,18J.Napolitano,18Q.He,19
J.Insler,19H.Muramatsu,19C.S.Park,19E.H.Thorndike,19F.Yang,19M.Artuso,20
S.Blusk,20S.Khalil,20J.Li,20R.Mountain,20S.Nisar,20K.Randrianarivony,20
N.Sultana,20T.Skwarnicki,20S.Stone,20J.C.Wang,20L.M.Zhang,20
G.Bonvicini,21D.Cinabro,21M.Dubrovin,21A.Lincoln,21and J.Rademacker 22
(CLEO Collaboration)
1
Carleton University,Ottawa,Ontario,Canada K1S 5B62
Carnegie Mellon University,Pittsburgh,Pennsylvania 15213,USA 3
Enrico Fermi Institute,University of Chicago,Chicago,Illinois 60637,USA
4
Cornell University,Ithaca,New York 14853,USA 5
University of Florida,Gainesville,Florida 32611,USA 6
George Mason University,Fairfax,Virginia 22030,USA 7
University of Illinois,Urbana-Champaign,Illinois 61801,USA 8
Indiana University,Bloomington,Indiana 47405,USA 9
University of Kansas,Lawrence,Kansas 66045,USA
10
Luther College,Decorah,Iowa 52101,USA
11
University of Minnesota,Minneapolis,Minnesota 55455,USA 12
Northwestern University,Evanston,Illinois 60208,USA
13
University of Oxford,Oxford OX13RH,UK
14
State University of New York at Bu?alo,Bu?alo,New York 14260,U SA
15
University of Pittsburgh,Pittsburgh,Pennsylvania 15260,USA 16
University of Puerto Rico,Mayaguez,Puerto Rico 0068117
Purdue University,West Lafayette,Indiana 47907,USA 18
Rensselaer Polytechnic Institute,Troy,New York 12180,USA 19
University of Rochester,Rochester,New York 14627,USA 20
Syracuse University,Syracuse,New York 13244,USA 21
Wayne State University,Detroit,Michigan 48202,USA
22
University of Bristol,Bristol BS81TL,UK
(Dated:February15,2008)
Abstract
We exploit the quantum coherence between pair-produced D0andˉD0inψ(3770)decays to study
charm mixing,which is characterized by the parameters x and y,and to make a?rst determination
of the relative strong phaseδbetween D0→K+π?andˉD0→K+π?.Using281pb?1of e+e?collision data collected with the CLEO-c detector at E cm=3.77GeV,as well as branching fraction
input from other experiments,we?nd cosδ=1.03+0.31
?0.17±0.06,where the uncertainties are statistical and systematic,respectively.In addition,by further including external measurements of charm mixing parameters,we obtain an alternate measurement of cosδ=1.10±0.35±0.07,as well as
x sinδ=(4.4+2.7
?1.8±2.9)×10?3andδ=(22+11?12+9?11)?.
PACS numbers:12.15.Ff,13.20.Fc,13.25.Ft,14.40.Lb
I.INTRODUCTION
Recent measurements of D 0-ˉD
0mixing parameters [1–4]highlight the need for informa-tion on the relative phase between the Cabibbo-favored decay D 0→K ?π+and the doubly
Cabibbo-suppressed (DCS)decay ˉD
0→K ?π+.Here,we present a measurement that takes advantage of the correlated production of D 0and ˉD
0mesons in e +e ?collisions.If there are no accompanying particles,the D 0ˉD
0pair is in a quantum-coherent C =?1state.Because the initial state (the virtual photon)has J P C =1??,there follows a set of selection rules
for the decays of the D 0and ˉD
0[5–15].For example,both D 0and ˉD 0cannot decay to CP eigenstates with the same eigenvalue.On the other hand,decays to CP eigenstates of opposite eigenvalue are enhanced by a factor of two.More generally,?nal states that can be
reached by both D 0and ˉD
0(such as K ?π+)are subject to similar interference e?ects.As a result,the e?ective D 0branching fractions in this D 0ˉD
0system di?er from those measured in isolated D 0mesons.Moreover,using time-independent rate measurements,it becomes
possible to probe D 0-ˉD
0mixing as well as the relative strong phases between D 0and ˉD 0decay amplitudes to any given ?nal state.
In the Standard Model,D 0-ˉD
0mixing is suppressed both by the GIM mechanism and by CKM matrix elements,although sizeable mixing could arise from new physics [14].Charm mixing is conventionally described by two small dimensionless parameters:
x =2
M 2?M 1
Γ2+Γ1
,
(2)
where M 1,2and Γ1,2are the masses and widths,respectively,of the neutral D meson CP eigenstates,D 1(CP -odd)and D 2(CP -even),which are de?ned as follows:
|D 1 ≡
|D 0 +|ˉD
0 2(3)|D 2 ≡|D 0 ?|ˉD
0 2
,
(4)
assuming CP conservation.The mixing probability is then denoted by R M ≡(x 2+y 2)/2,
and the width of the D 0and ˉD
0?avor eigenstates is Γ≡(Γ1+Γ2)/2.Many previous searches for charm mixing have focused on D 0decay times.Direct mea-surements of y come from comparing lifetimes in D 0→K +K ?and π+π?decay to that in D 0→K ?π+.An indirect measure of y is provided by the “wrong-sign”process D 0→K +π?,where interference between the DCS amplitude and the mixing amplitude manifests itself in the apparent D 0lifetime.These analyses are sensitive to y ′≡y cos δ?x sin δ,
where ?δis the phase of the amplitude ratio K +π?|D 0 / K +π?|ˉD
0 ≡re ?iδ.We adopt a convention in which δcorresponds to a strong phase,which vanishes in the SU(3)limit [13].Because δhas not previously been measured,the separate determinations of y and y ′above have not been directly comparable.The magnitude r of the amplitude ratio is approximately 0.06.
In this article,we present an implementation of the method described in Ref.[16]for measuring y and δusing quantum correlations at the ψ(3770)resonance.Our experimen-tal technique is an extension of the double tagging method previously used to determine
absolute hadronic D -meson branching fractions at CLEO-c [17].This method combines
yields of fully reconstructed single tags (ST),which are individually reconstructed D 0or ˉD 0candidates,with yields of double tags (DT),which are events where both D 0and ˉD
0are reconstructed,to give absolute branching fractions without needing to know the luminosity
or D 0ˉD
0production cross section.Given a set of input yields,e?ciencies,and background estimates,a least-squares ?tter [18]extracts the number of D 0ˉD
0pairs produced (N )and the branching fractions (B )of the reconstructed D 0?nal states,while accounting for all sta-tistical and systematic uncertainties and their correlations.We employ a modi?ed version of this ?tter that also determines y ,x 2,r 2,r cos δ,and rx sin δusing the following cate-gories of reconstructed ?nal states:K ?π+(f ),K +π+(ˉf
),CP -even (S +)and CP -odd (S ?)eigenstates,and semileptonic decays (e ±).For optimal precision on δ,we also incorporate measurements of branching fractions and mixing parameters from other CLEO-c analyses or from external sources.We neglect CP violation in D decays,which would entail a slight correction to the mixing signal.
The paper is organized as follows.In Section II,we review the formalism of quantum-correlated D 0ˉD
0decay.Section III describes the event selection criteria and D reconstruction procedures.The external measurements used in the ?t are summarized in Section IV.Systematic uncertainties,which are also input to the ?t,are discussed in Section V.Finally,we present and discuss our ?t results in Section VI.
II.
FORMALISM
To ?rst order in x and y ,the C -odd rate ΓD 0ˉD 0(i,j )for D 0ˉD
decay to ?nal state {i,j }follows from the anti-symmetric amplitude M ij :
ΓD 0ˉD 0(i,j )∝M 2ij = A i ˉA j ?ˉA i A j
2
=| i |D 2 j |D 1 ? i |D 1 j |D 2 |2,
(5)
where A i ≡ i |D 0 and ˉA
i ≡ i |ˉD 0 .These amplitudes are normalized such that B K ?π+≈A 2K ?π+(1+ry cos δ+rx sin δ),B S ±≈A 2S ±(1?y ),and B e ≈A 2
e .The total rate,ΓD 0ˉD
0,is the same as for uncorrelated decay,as are ST rates.However,unlike the case of uncorrelated D 0ˉD
0,we can consider the C -odd D 0ˉD 0system as a D 1D 2pair.If only ?avored ?nal states are considered,as in Ref.[17],then the e?ects of quantum correlations are negligible.In this analysis,we also include CP eigenstates,which brings additional sensitivity to y and δ,as demonstrated below.
Quantum-correlated semileptonic rates probe y because the decay width does not depend on the CP eigenvalue of the parent D meson,as this weak decay is only sensitive to ?avor content.However,the total width of the parent meson does depend on its CP eigenvalue:Γ12
=Γ(1?y ),so the semileptonic branching fraction for D 1or D 2is modi?ed by 1±y .
If we reconstruct a semileptonic decay in the same event as a D 2→S +decay,then the
semileptonic D must be a D 1.Therefore,the e?ective quantum-correlated D 0ˉD
0branching fractions (F cor )for {S ±,e }?nal states depend on y :
F cor S ±,e
≈2B S ±B e (1±y ),(6)
where the factor of 2arises from the sum of e +and e ?https://www.doczj.com/doc/f91183233.html,bined with estimates
of B e and B S ±from ST yields,external sources,and ?avor-tagged semileptonic yields,this equation allows y to be determined.
Similarly,if we reconstruct a D →K ?π+decay in the same event as a D 2→S +,then the K ?π+was produced from a D 1.The e?ective branching fraction for this DT process is therefore
F cor
S +,K ?π
+=| S +|D 2 K ?π+|D 1 |2≈B S +(1+y )|A K ?π++ˉA
K ?π+|2≈B S +B K ?π+(1+y )(1?ry cos δ?rx sin δ)|1+re ?iδ|2
=B S +B K ?π+(1+y )(1?ry cos δ?rx sin δ)(1+2r cos δ+r 2)≈B S +B K ?π+(1+2r cos δ+R WS +y ),
(7)
where R WS is the wrong-sign rate ratio,which depends on x and y because of the interference
between DCS and mixing transitions:R WS ≡Γ(ˉD
0→K ?π+)/Γ(D 0→K ?π+)=r 2+ry ′+R M .In an analogous fashion,we ?nd F cor
S ?,K ?π
+≈B S ?B K ?π+(1+R WS ?2r cos δ?y ).When combined with knowledge of B S +,y ,and r ,the asymmetry between these two DT yields gives cos δ.In the absence of quantum correlations,the e?ective branching fractions above would be B S ±B K ?π+(1+R WS ).
More concretely,we evaluate Eq.(5)with the above de?nitions of r and δto produce the expressions in Table I.In doing so,we use the fact that inclusive ST rates are given by the
incoherent branching fractions since each event contains one D 0and one ˉD
https://www.doczj.com/doc/f91183233.html,parison of F cor with the uncorrelated e?ective branching fractions,F unc ,also given in Table I,allows us to extract r 2,r cos δ,y ,x 2,and rx sin δ.Information on B i is obtained from ST yields at the ψ(3770)and from external measurements using incoherently produced D 0mesons.These two estimates of B i are averaged by the ?tter to obtain F unc .
TABLE I:Correlated (C -odd)and uncorrelated e?ective D 0ˉD
0branching fractions,F cor and F unc ,to leading order in x ,y and R WS ,divided by B i for ST modes i (?rst section)and B i B j for DT modes {i,j }(second section).Charge conjugate modes are implied.
Mode
Correlated
Uncorrelated
K ?π+,K ?π+R M
R WS
K ?π+,K +π?(1+R WS )2?4r cos δ(r cos δ+y )1+R 2WS
K ?π+,S +1+R WS +2r cos δ+y 1+R WS K ?π+,S ?1+R WS ?2r cos δ?y 1+R WS
K ?π+,e ?1?ry cos δ?rx sin δ1S +,S +01S ?,S ?01S +,S ?42S +,e ?1+y 1S ?,e ?1?y
1
Using only ST and DT yields at the ψ(3770),we can determine y and cos δfrom the
following double ratios,obtained by manipulating the expressions in Table I:
y ≈
N fe N S ?e ?N S +
4 N S +e N S ?
N S +e N S ?
(9)
2r cos δ+y ≈
N f ˉ
f N S ?f
?N S +4N f N S +S ?
1
N fS +N S ?
,(11)
where N denotes an e?ciency-corrected background-subtracted ST or DT yield.Note that semileptonic yields are essential for separating y and cos δ.Including external branching fractions provides additional ways to determine y and cos δ:
y =±
1?
2N B S ±B e
N S +f /B S ++N S ?f /B S ?
.
(13)
Although we neglect x 2and y 2terms in general,we report a result for x 2as determined solely from N ff /N f ˉf .
III.
EVENT SELECTION AND RECONSTRUCTION
Our current analysis uses 281pb ?1of e +e ?→ψ(3770)data collected with the CLEO-c [19–23]detector.We also make use of a large Monte Carlo simulated sample
of uncorrelated D 0ˉD
0decays with an e?ective luminosity 40times that of our data sample,from which we estimate signal e?ciencies,crossfeed probabilities among signal modes,and background contributions.In these samples,we reconstruct the ?nal states shown in Ta-ble II,with π0→γγ,η→γγ,K 0S →π+π?,and ω→π+π?π0.Because most K 0
L mesons
and neutrinos are not detected,we do not reconstruct K 0L π0
and semileptonic ST modes;they are only included in DT modes,paired with a fully reconstructed D candidate.Below,
we denote by S ′
+the subset of S +modes that are fully reconstructed:K +K ?,π+π?,and K 0S π0π0.For CP eigenstates,we choose modes with unambiguous CP content.In addition
to two-body decays,we also include K 0S π0π0
,which is a pure CP -even eigenstate because the two identical π0’s must have even angular momentum in order to satisfy Bose symmetry.We neglect CP violation in K 0decays.
Standard CLEO-c selection critera for π±,K ±,π0,and K 0
S candidates are described in
Ref.[24].In addition,for K 0S candidates,we impose |M (π+π?
)?M K 0S
|<7.5MeV/c 2,and we require the decay vertex to be separated from the interaction region with a signi?cance
greater than two standard deviations (σ).For the K 0S π0π0mode,we reject K 0
S daughter tracks with ionization energy loss consistent with being kaons at the level of 2σin order to suppress misreconstructed D →K ?π+π0decays,where the kaon is taken to be a charged pion,and an extra soft combinatoric π0candidate is incorporated into the D candidate.We
TABLE II:D?nal states reconstructed in this analysis.
Type Final States
E20/c4?p2D/c2(14)
?E≡E D?E0,(15) where p D and E D are the total momentum and energy of the D candidate,and E0is the beam energy.Correctly reconstructed D candidates produce a peak in M at the D mass and in?E at zero.We determine ST yields by?tting the M distribution with the mode-dependent requirements on?E listed in Table III,which are applied to both ST and DT D candidates.The limits are set at approximately three standard deviations.Modes withπ0 orη,which decay to two photons,have asymmetric limits to allow for partially contained showers in the electromagnetic calorimeter.
TABLE III:Requirements on?E for D candidates.
Mode Requirement(GeV)
MeV not associated with the signal tracks.For K+K?ST candidates,additional geometric requirements are needed to remove doubly radiative Bhabhas followed by pair conversion of a radiated photon.Also,we accept only one candidate per mode per event;when multiple candidates are present,we choose the one with smallest|?E|.
The resultant M distributions,shown in Fig.1,are?tted to a signal shape derived from simulated signal events and to a background ARGUS function[26].The simulated signal shape is both shifted and convoluted with a Gaussian smearing function to account for im-perfect modeling of the detector resolution and beam energy calibration.The width of the smearing function is allowed to?oat in the?t.The measured ST yields and e?ciencies are given in Table IV.The yield uncertainties are statistical and uncorrelated systematic, respectively.The latter arise from modeling of multiple candidates in simulation and vari-ations in the signal lineshape.Correlated systematic uncertainties are discussed separately in Section V.
TABLE IV:ST yields and e?ciencies input to the data?t.Yield uncertainties are statistical and uncorrelated systematic,respectively,and e?ciency uncertainties are statistical only.
Mode Yield E?ciency(%)
FIG.1:ST M distributions and?ts.Data are shown as points with error bars.The solid lines show the total?ts,and the dashed lines show the background shapes.
3.Semileptonic Double Tags
Semileptonic DTs are partially reconstructed by combining a fully reconstructed hadronic ST with an electron candidate from the remainder of the event.The hadronic tags are selected using the same criteria as for STs,described in in Section III1,with an additional mode-dependent M requirement listed in Table VI.The limits are set at approximately three standard deviations.Multiple tag candidates are resolved with minimal|?E|,as for STs.All electron candidates in a given event are accepted.
Electron candidate tracks must have momentum greater than200MeV/c and impact parameters with respect to the event origin of less than5mm in the r-φplane and less than5 cm in the z dimension.We also require the track to have more than half the hits expected for
FIG.2:Two-dimensional M distributions with signal(S)and sideband(A,B,C,D)regions depicted,for the sum of all{K?π±,S′+}and{K?π±,S?}modes listed in Table V.
its momentum and to have|cosθ|<0.9,whereθis the angle between the track momentum vector and the beam line at the interaction point.These criteria remove kinematic regions with high background.When paired with a K?π±tag,the kaon and electron charges must be the same.This requirement removes charge-symmetric backgrounds and cannot be used with un?avored S±tag modes.
Electrons are distinguished from hadrons via a multivariate discriminant[27]that com-bines information from the ratio of the energy deposited in the calorimeter to the measured track momentum(E/p),ionization energy loss in the tracking chambers(dE/dx),and the ring-imagingˇCerenkov counter(RICH).The ratio of electron likelihood to the sum of elec-tron,pion,and kaon likelihoods is required to be greater than0.8.
As illustrated in Fig.4,the resulting electron momentum spectrum for each tag mode is?t to signal and background shapes determined from the simulation.We correct the simulated spectrum for relative bin-by-bin e?ciency di?erences between data and simulation,which are measured with a high-statistics radiative Bhabha sample.The background components in the spectrum?t include misreconstructed tags,photon conversions and light hadron decays to electrons(mostlyπ0Dalitz decays),weak decays in?ight,and hadron misidenti?cation. The latter component peaks at700MeV/c and mostly consists of K±that escape the acceptance of the RICH;K±are indistinguishable from e±using dE/dx at this momentum. In the?t,the misreconstructed tag component is?xed from sidebands in M and?E.The other backgrounds contribute approximately7%for K?π±tags and20–30%for S±tags.
Table VII gives the semileptonic DT yields and e?ciencies input to the?t.The uncorre-lated systematic uncertainties are determined from yield excursions under variation of the spectrum?t.
FIG.3:Sums of fully reconstructed DTˉM distributions,with charge conjugate modes implied. Data are shown as points with error bars.The shaded histograms show events outside the signal region.
4.Double Tags with K0Lπ0
DT modes with K0Lπ0are reconstructed with the missing mass technique also used in Ref.[28].A fully reconstructed ST candidate,selected as described in Section III1,is combined with aπ0candidate,and we compute the squared recoil mass against the ST-π0
.Backgrounds from system,M2miss.Signal K0Lπ0decays produce a peak in M2miss at M K0
L
D→K0Sπ0,π0π0,andηπ0are suppressed by vetoing events with additional unassigned charged particles,η,orπ0candidates.
Figure5shows the resultant M2miss in data.Signal yields are obtained from event counts in the signal region of0.1 Table VIII lists the K0Lπ0DT yields and e?ciencies input to the?t.There are no uncorrelated systematic uncertainties for these modes. 5.Crossfeed and Peaking Backgrounds TABLE V:Fully reconstructed DT yields and e?ciencies input to the data?t.Yield uncertainties are statistical and uncorrelated systematic(for sideband subtraction),respectively,and e?ciency uncertainties are statistical only. Mode Yield E?ciency(%) TABLE VI:Requirements on M for hadronic tags in semileptonic DT candidates Mode Requirement(GeV/c2) TABLE VII:Semileptonic DT yields and e?ciencies input to the data?t.Yield uncertainties are statistical and uncorrelated systematic,respectively,and e?ciency uncertainties are statistical only. Mode Yield E?ciency(%) K0Lπ0,K?π+187±1434.0±0.2 K0Lπ0,K+π?179±1434.8±0.2 K0Lπ0,K0Sπ090±1015.5±0.1 K0Lπ0,K0Sη8.6±3.15.4±0.1 K0Lπ0,K0Sω34±66.2±0.1 shows the sources of these measurements,and there is no overlap among the measurements in these Tables. A.External Branching Ratio Measurements Because our precision on cosδis currently limited by our knowledge of the CP-eigenstate branching fractions,we include as many external measurements of these branching fractions as possible.Except for the inclusive B(K0Sπ0π0)and B(K0Lπ0),all CP-eigenstates in this analysis have previous branching ratio measurements with respect to other reference modes. For K0Sπ0,K0Sη,and K0Sω,we make use of the global branching fraction?t performed in Ref.[29].Because B(K?π+)is a free parameter in this?t and in the current analysis,we also include Ref.[29]’s?t result for this mode in order to properly account for the correlations among these branching fractions.We do not use Ref.[25]because this compilation includes a CLEO-c measurement of B(K?π+)[17],which is correlated with the measurements in this FIG.5:Sums of M2miss distributions for K0Lπ0.The dashed lines represent simulations of the peaking backgrounds D0→π0π0(dashed),K0Sπ0(dotted),ηπ0(long-dashed),and K?0π0(dot-dashed). analysis. Previous experiments have measured R KK≡B(K?K+)/B(K?π+)and Rππ≡B(π?π+)/B(K?π+)simultaneously[25],so these two quantities are correlated both sta-tistically[via the common denominator,B(K?π+)]and systematically.It is common for these experiments to also report a value of R KK/Rππin addition to R KK and Rππhttps://www.doczj.com/doc/f91183233.html,ing the dominant measurements of all three quantities[30–33],we compute a weighted average correlation coe?cient of0.30between the R KK and Rππvalues quoted in Ref[25].For Rππ,we remove the CLEO-c measurement[34]from the average because it was based on the same dataset as this analysis. π0analysis[28],provides additional information on B(K0Lπ0) The CLEO-c D→K0 S/L from the K?π+π0and K?π+π?π+tag modes,which are not used in this analysis.Sys-tematic correlations between the K0Lπ0yields in this analysis and these additional B(K0Lπ0) measurements is taken into account.We also include the statistical correlation between B(K0Lπ0)and B(K0Sπ0);knowledge of the latter is required to correct for the e?ect of quan-tum correlations in the former. Table X summarizes the external branching fraction inputs to the?t. TABLE IX:Crossfeed probabilities and peaking background e?ciencies and branching fractions input to the?t.Backgrounds marked by an asterisk(*)occur in only in STs,not DTs. Crossfeed→Signal E?ciency(%) Background→Signal B bkg(%)[25]E?ciency(%) Γ(ˉD0→K+π?)(16) =r2+ry′+R M(17) =r2+√ r2x sinδ+ x2+y2 TABLE X:External branching ratio measurements and their correlations used in the data?t.An asterisk(*)indicates removal of overlapping CLEO-c measurements. Parameter Value(%)Correlation Coe?cients r2+ry′Γt+x′2+y′2 dt∝eΓt R WS0.409±0.022[35–37] R M0.0173±0.0387[38–41] 2.Measurements of y and y′ By combining external measurements of y and y′with the CLEO-c measurement of cosδ, the?tter can extract x sinδvia x sinδ=y cosδ?y′.In doing so,it accounts for the fact that y′is determined simultaneously with r2and R M,which are also functions of the?t parameters,and that cosδand its uncertainty are correlated with y(as discussed below in Section VI). External measurements of y come from two sources:comparison of D0decay times to CP eigenstates K+K?andπ+π?with decay times to the?avor eigenstate K?π+,and time-dependent Dalitz plot analysis of D→K0Sπ+π?,which is sensitive to both x and y. The latter x and y measurements are essentially uncorrelated,but x provides information on y when combined with measurements of R M. For y′,we use three sets of(CP-conserving)?t results from CLEO,Belle,and BABAR. Averages of these?ts are shown in Table XII.The?t covariance matrices have been provided by the above collaborations and are also included in our analysis. TABLE XII:External measurements of y and y′with associated measurements of r2and x′2. Parameter Value(%) Table XIV shows mode-dependent uncertainties.Most are assessed by relaxing selection requirements and noting the resultant change in e?ciency-corrected yield.The e?ect of modeling of the K0Sπ0π0resonant substructure on the e?ciency is determined by reweighting the simulated events according to the substructure observed in data and recomputing the e?ciency.We assign a conservative uncertainty for the modeling of multiple candidates by taking the di?erence between multiple candidate rates in simulated events and data. The e?ciency of the extra track,π0,andηvetos in K0Lπ0modes is studied by comparing the frequency of these extra particles between simulated events and data.For semileptonic decays,we extrapolate the observed electron momentum spectrum below200MeV/c based on the simulation,and we take25%of the fraction below this momentum as an associated uncertainty. In our simulation,?nal state radiation(FSR)is generated by PHOTOS[50].We measure e?ciencies with and without FSR generation and assign30%of the di?erence as a systematic uncertainty.We also include a contribution corresponding to the change in e?ciency when PHOTOS does and does not model interference among the radiated photons. Unlike FSR,initial state radiation(ISR)coherently shifts both M values upward in a signal DT.So,mismodeling of ISR would a?ect ST and DT e?ciencies by the same fraction. Based on a study of excluding events in the ISR region(M>1.87GeV/c2),we assign a conservative0.5%uncertainty to all yields. TABLE XIII:Correlated,fractional e?ciency systematic uncertainties and the schemes for applying them in the data branching fraction?t. Source Uncertainty(%)Scheme TABLE XIV:Correlated,mode-dependent fractional systematic uncertainties in percent for STs. An asterisk(*)marks those uncertainties that are correlated among modes.The schemes by which these uncertainties are applied to DTs are also given,along with the fractional DT uncertainty,λDT,on mode{A,B}for ST uncertainties ofαon mode A andβon mode B. ?E ISR*FSR*Lepton Veto*Other Scheme per D per yield per D per ST per D λDT α2+β2 being at the boundary of the physical region.Our value of y is consistent with the world average of0.00662±0.00211(see Table XII).Our branching fraction results do not supersede other CLEO-c measurements. The likelihood curve for cosδis obtained by repeating this?t at?xed values of cosδand recording the change in optimizedχ2.We then compute L=e?(χ2?χ2min)/2,which is shown in Fig.6a.It is highly non-Gaussian,so we assign asymmetric uncertainties by?nding the values of cosδwhere?χ2=1to obtain cosδ=1.03+0.31 ?0.17±0.06.For values of|cosδ|<1, we also compute L as a function of|δ|,and we integrate these curves within the physical region to obtain95%con?dence level limits of cosδ>0.07and|δ|<75?. The asymmetric uncertainties on cosδquoted above still do not fully capture the non-linearity of the likelihood.This non-linearity stems from the use of r2to convert r cosδinto cosδ,which causes the uncertainty on cosδto scale roughly like1/r.Because r2is obtained from R WS via Eq.(18),an upward shift in y lowers the derived value of r2(for positive r cosδ).As a result,the uncertainty on cosδincreases with more positive y,as shown in Fig.6b.A second,smaller e?ect is that the sign of the correlation between r2and r cosδis given by the sign of y.When y is positive,r2and r cosδare anti-correlated,which tends to in?ate the uncertainty on cosδ. We also perform an extended?t that determines x sinδby including previous measure-ments of y and y′.Table XV shows the results of this?t,which incorporates all external The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中 定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way... “tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法 不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke. 表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法 The way的用法及其含义（一） 有这样一个句子：In 1770 the room was completed the way she wanted. 1770年，这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么？其意义如何？在阅读时，学生经常会碰到一些含有the way 的句子，如：No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中，the way之后的部分都是定语从句。第一句的意思是，“没人知道他是怎样发明这台机器的。”the way的意思相当于how；第二句的意思是，“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中，the way也是as的含义。随着现代英语的发展，the way的用法已越来越普遍了。下面，我们从the way的语法作用和意义等方面做一考查和分析： 一、the way作先行词，后接定语从句 以下3种表达都是正确的。例如：“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如：“火灾如何发生的，有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started. way 的用法 【语境展示】 1. Now I’ll show you how to do the experiment in a different way. 下面我来演示如何用一种不同的方法做这个实验。 2. The teacher had a strange way to make his classes lively and interesting. 这位老师有种奇怪的办法让他的课生动有趣。 3. Can you tell me the best way of working out this problem? 你能告诉我算出这道题的最好方法吗？ 4. I don’t know the way (that / in which) he helped her out. 我不知道他用什么方法帮助她摆脱困境的。 5. The way (that / which) he talked about to solve the problem was difficult to understand. 他所谈到的解决这个问题的方法难以理解。 6. I don’t like the way that / which is being widely used for saving water. 我不喜欢这种正在被广泛使用的节水方法。 7. They did not do it the way we do now. 他们以前的做法和我们现在不一样。 【归纳总结】 ●way作“方法，方式”讲时，如表示“以……方式”，前面常加介词in。如例1； ●way作“方法，方式”讲时，其后可接不定式to do sth.，也可接of doing sth. 作定语，表示做某事的方法。如例2，例3； t h e-w a y-的用法 The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. way的用法总结大全 way的用法你知道多少，今天给大家带来way的用法，希望能够帮助到大家，下面就和大家分享，来欣赏一下吧。 way的用法总结大全 way的意思 n. 道路,方法,方向,某方面 adv. 远远地，大大地 way用法 way可以用作名词 way的基本意思是“路,道,街,径”,一般用来指具体的“路,道路”,也可指通向某地的“方向”“路线”或做某事所采用的手段,即“方式,方法”。way还可指“习俗,作风”“距离”“附近,周围”“某方面”等。 way作“方法,方式,手段”解时,前面常加介词in。如果way前有this, that等限定词,介词可省略,但如果放在句首,介词则不可省略。 way作“方式,方法”解时,其后可接of v -ing或to- v 作定语,也可接定语从句,引导从句的关系代词或关系副词常可省略。 way用作名词的用法例句 I am on my way to the grocery store.我正在去杂货店的路上。 We lost the way in the dark.我们在黑夜中迷路了。 He asked me the way to London.他问我去伦敦的路。 way可以用作副词 way用作副词时意思是“远远地,大大地”,通常指在程度或距离上有一定的差距。 way back表示“很久以前”。 way用作副词的用法例句 It seems like Im always way too busy with work.我工作总是太忙了。 His ideas were way ahead of his time.他的思想远远超越了他那个时代。 She finished the race way ahead of the other runners.她第一个跑到终点,远远领先于其他选手。 way用法例句 t h e_w a y的用法大全 The way 在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms. 从那天起,其他同学是夹着书本来上课,而他们却带着"失败"的思想负担来上课. The way的用法及其含义（三） 三、the way的语义 1. the way=as（像） Please do it the way I’ve told you.请按照我告诉你的那样做。 I'm talking to you just the way I'd talk to a boy of my own.我和你说话就像和自己孩子说话一样。 Plant need water the way they need sun light. 植物需要水就像它们需要阳光一样。 2. the way=how（怎样，多么） No one can imagine the way he misses her.没人能够想象出他是多么想念她！ I want to find out the way a volcano has formed.我想弄清楚火山是怎样形成的。 He was filled with anger at the way he had been treated.他因遭受如此待遇而怒火满腔。That’s the way she speaks.她就是那样讲话的。 3. the way=according as （根据） The way you answer the questions, you must be an excellent student.从你回答问题来看，你一定是名优秀的学生。 The way most people look at you, you'd think a trash man was a monster.从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物。 The way I look at it, it’s not what you do that matters so much.依我看，重要的并不是你做什么。 I might have been his son the way he talked.根据他说话的样子，好像我是他的儿子一样。One would think these men owned the earth the way they behave.他们这样行动，人家竟会以为他们是地球的主人。 一．Way：“方式”、“方法” 1.表示用某种方法或按某种方式 Do it (in) your own way. Please do not talk (in) that way. 2.表示做某事的方式或方法 It’s the best way of studying [to study] English.。 There are different ways to do [of doing] it. 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句 正：I don’t like the way he spoke. I don’t like the way that he spoke. I don’t like the way in which he spoke.误：I don’t like the way how he spoke. 4. the way 的从句 That’s the way (=how) he spoke. I know where you are from by the way you pronounce my name. That was the way minority nationalities were treated in old China. Nobody else loves you the way(=as) I do. He did not do it the way his friend did. 二．固定搭配 1. In a/one way：In a way he was right. 2. In the way /get in one’s way I'm afraid your car is in the way， If you are not going to help，at least don't get in the way. You'll have to move－you're in my way. 3. in no way Theory can in no way be separated from practice. 4. On the way (to……) Let’s wait a few moments. He is on the way Spring is on the way. Radio forecasts said a sixth-grade wind was on the way. She has two children with another one on the way. 5. By the way By the way，do you know where Mary lives? 6. By way of Learn English by way of watching US TV series. 8. under way 1. Elbow one’s way He elbowed his way to the front of the queue. 2. shoulder one’s way 3. feel one‘s way 摸索着向前走；We couldn’t see anything in the cave, so we had to feel our way out 4. fight/force one’s way 突破。。。而前进The surrounded soldiers fought their way out. 5.. push/thrust one‘s way（在人群中）挤出一条路He pushed his way through the crowd. 6. wind one’s way 蜿蜒前进 7. lead the way 带路，领路；示范 8. lose one‘s way 迷失方向 9. clear the way 排除障碍，开路迷路 10. make one’s way 前进，行进The team slowly made their way through the jungle. 在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms. “the way+从句”结构的意义及用法 首先让我们来看下面这个句子： Read the following passage and talk about it with your classmates. Try to tell what you think of Tom and of the way the children treated him. 在这个句子中，the way是先行词，后面是省略了关系副词that 或in which的定语从句。 下面我们将叙述“the way+从句”结构的用法。 1．the way之后，引导定语从句的关系词是that而不是how,因此，<<现代英语惯用法词典>>中所给出的下面两个句子是错误的：This is the way how it happened. This is the way how he always treats me. 2. 在正式语体中，that可被in which所代替；在非正式语体中，that则往往省略。由此我们得到the way后接定语从句时的三种模式：1) the way +that-从句2) the way +in which-从句3) the way +从句 例如：The way(in which ,that) these comrades look at problems is wrong.这些同志看问题的方法不对。 The way(that ,in which)you’re doing it is completely crazy.你这么个干法，简直发疯。 We admired him for the way in which he faces difficulties. Wallace and Darwin greed on the way in which different forms of life had begun.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 This is the way (that) he did it. I liked the way (that) she organized the meeting. 3.the way(that)有时可以与how(作“如何”解)通用。例如： That’s the way (that) she spoke. = That’s how she spoke. I should like to know the way/how you learned to master the fundamental technique within so short a time. 4．the way的其它用法：以上我们讲的都是用作先行词的the way，下面我们将叙述它的一些用法。 定冠词the的12种用法 定冠词the 的12 种用法，全知道?快来一起学习吧。下面就和大家分享，来欣赏一下吧。 定冠词the 的12 种用法，全知道? 定冠词the用在各种名词前面，目的是对这个名词做个记号，表示它的特指属性。所以在词汇表中，定冠词the 的词义是“这个，那个，这些，那些”，可见，the 即可以放在可数名词前，也可以修饰不可数名词，the 后面的名词可以是单数，也可以是复数。 定冠词的基本用法： (1) 表示对某人、某物进行特指，所谓的特指就是“不是别的，就是那个!”如： The girl with a red cap is Susan. 戴了个红帽子的女孩是苏珊。 (2) 一旦用到the，表示谈话的俩人都知道说的谁、说的啥。如： The dog is sick. 狗狗病了。(双方都知道是哪一只狗) (3) 前面提到过的，后文又提到。如： There is a cat in the tree.Thecat is black. 树上有一只猫，猫是黑色的。 (4) 表示世界上唯一的事物。如： The Great Wall is a wonder.万里长城是个奇迹。(5) 方位名词前。如： thenorth of the Yangtze River 长江以北地区 (6) 在序数词和形容词最高级的前面。如： Who is the first?谁第一个? Sam is the tallest.山姆最高。 但是不能认为，最高级前必须加the，如： My best friend. 我最好的朋友。 (7) 在乐器前。如： play the flute 吹笛子 Way用法 A:I think you should phone Jenny and say sorry to her. B:_______. It was her fault. A. No way B. Not possible C. No chance D. Not at all 说明：正确答案是A. No way，意思是“别想！没门！决不！” 我认为你应该打电话给珍妮并向她道歉。 没门！这是她的错。 再看两个关于no way的例句： （1）Give up our tea break? NO way! 让我们放弃喝茶的休息时间？没门儿！ （2）No way will I go on working for that boss. 我决不再给那个老板干了。 way一词含义丰富，由它构成的短语用法也很灵活。为了便于同学们掌握和用好它，现结合实例将其用法归纳如下： 一、way的含义 1. 路线 He asked me the way to London. 他问我去伦敦的路。 We had to pick our way along the muddy track. 我们不得不在泥泞的小道上择路而行。 2. （沿某）方向 Look this way, please. 请往这边看。 Kindly step this way, ladies and gentlemen. 女士们、先生们，请这边走。 Look both ways before crossing the road. 过马路前向两边看一看。 Make sure that the sign is right way up. 一定要把符号的上下弄对。 3. 道、路、街，常用以构成复合词 a highway（公路），a waterway（水路），a railway（铁路），wayside（路边） way/time的特殊用法 1、当先行词是way意思为”方式.方法”的时候,引导定语从句的关系词有下列3种形式： Way在从句中做宾语 The way that / which he explained to us is quite simple. Way在从句中做状语 The way t hat /in which he explained the sentence to us is quite simple. 2、当先行词是time时,若time表示次数时,应用关系代词that引导定语从句,that可以省略; 若time表示”一段时间”讲时,应用关系副词when或介词at/during + which引导定语从句 1.Is this factory _______ we visited last year? 2.Is this the factory-------we visited last year? A. where B in which C the one D which 3. This is the last time _________ I shall give you a lesson. A. when B that C which D in which 4.I don’t like the way ________ you laugh at her. A . that B on which C which D as 5.He didn’t understand the wa y ________ I worked out the problem. A which B in which C where D what 6.I could hardly remember how many times----I’ve failed. A that B which C in which D when 7.This is the second time--------the president has visited the country. A which B where C that D in which 8.This was at a time------there were no televisions, no computers or radios. A what B when C which D thatThe way常见用法
The way的用法及其含义(二)
(完整版)the的用法
“the way+从句”结构的意义及用法
way 用法
The way的用法及其含义(一)
way 的用法
the-way-的用法讲解学习
way的用法总结大全
the_way的用法大全教案资料
the way 的用法
The way的用法及其含义(三)
way的用法
the way的用法大全
“the-way+从句”结构的意义及用法知识讲解
定冠词the的12种用法
Way的用法
way与time的特殊用法
相关主题
文本预览