A test of CPT symmetry in K0 vs (K-)0→π+π-π0 decays

I show that the CP-violating asymmetry in K0 vs K-0→π+π-π0 decays differs from that in KL→π+π-,KL→π0π0 or the semileptonic KL transitions,if there exists CPT violation in K0-K-0 mixing.A delicate measurement of this difference at a super flavor factory(e.g.,the φ factory)will provide us with a robust test of CPT symmetry in the neutral kaon system.     

Recent results on light hadron spectroscopy from BES Ⅱ

We reported the observation of Y(2175) in φf0(980) mass spectrum in J/ψ→ηφf0(980) with f0(980)→π+π- and the observation of a broad 1-- resonance of K+K-mass in J/ψ→K+K-π0. The results from the partial wave analyses of Jψ→γπ+π- and γπ0π0, as well as J/ψ→pK-∧. are also presented.     

Measuring DO-D-O mixing in D→Fo(980)K* and more

We investigate the DO-D-O mixing through the doubly Cabibbo suppressed (DCS) channel DO→fO(980)K*O and its charge conjugate channel,in which the K*O meson is reconstructed in both K+π- and KsπO final state.Although the decay DO→ fo(980)K* has a small branching ratio,the final state mesons are relatively easy to identify.The fo(980) meson can be replaced by the S-wave π+π- state,or a longitudinally polarized vector meson pO.All mixing parameters,including the mass difference and decay width difference,can be extracted by studying the time-dependent decay width of these channels.We show that the method is valid in all regions for mixing parameters and it does not depend on the strong phase difference.     

Study of Exclusive Hadronic Decays for D0→Ks0π+π- and D0→Ks0K+K- and Their Resonant Structures

We report the results of an experimental study of the exclusive hadronic decays for D0→K0 sπ+π - and K 0 sK +K - and their resonant structures using BES-Ⅰ detector at the BEPC Collider. Using the data sample of 22.3 pb -1 collected at the center-of-mass energy s=4.03 GeV, we measured the branching fraction for D 0→K 0π +π - to be (5.32±0.53±0.40)%, the branching fractions for the decays D 0→ K *-π +, D 0→K 0ρ 0 and D 0→K 0(π +π -) non-resonant to be (6.05±0.32±0.49)%, (1.17±0.17±0.13)% and (1.35±0.22±0.17)%, respectively. We measured the branching fractions Br(D 0→f) to be (1.04±0.24± 0.16)% for f=K 0K +K -, (1.12±0.34±0.15)% for f=K0, and (0.27±0.13±0.03)% for f=K 0(K+K-)non-.     

First observation of the decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-)

First observations of the Cabibbo-suppressed decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-) are reported using 35 pb(-1) of data collected with the LHCb detector. Their branching fractions are measured with respect to the corresponding Cabibbo-favored decays, from which we obtain B(B(0) → D(+)K(-)π(+)π(-))/B(B(0) → D(+)π(-)π(+)π(-))=(5.9±1.1±0.5)×10(-2) and B(B(-) → D(0)K(-)π(+)π(-))/B(B(-) → D(0)π(-)π(+)π(-))=(9.4±1.3±0.9)×10(-2), where the uncertainties are statistical and systematic, respectively. The B(-) → D(0)K(-)π(+)π(-) decay is particularly interesting, as it can be used in a similar way to B(-) → D(0)K(-) to measure the Cabibbo-Kobayashi-Maskawa phase γ.     

Search for B+/--->[K(-/+)pi(+/-)](D)K+/- and upper limit on the b-->u amplitude in B+/--->DK+/-

We search for B+/--->[K(-/+)pi(+/-)](D)K+/- decays, where [K(-/+)pi(+/-)](D) indicates that the K-/+pi(+/-) pair originates from the decay of a D0 or D (0). Results are based on 120x10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at SLAC. We set an upper limit on the ratio R(Kpi) identical with[Gamma(B+-->[K(-)pi(+)](D)K+)+Gamma(B--->[K(+)pi(-)](D)K-)][Gamma(B+-->[K(+)pi(-)](D) / K+)+Gamma(B--->[K(-)pi(+)](D)K-)]<0.026 (90% C.L.). This constrains the amplitude ratio r(B) identical with|A(B--->D 0K-)/A(B--->D0K-)|<0.22 (90% C.L.), consistent with expectations. The small value of r(B) favored by our analysis suggests that the determination of the Cabibbo-Kobayashi-Maskawa phase gamma from B-->DK will be difficult.     

Precise measurement of the e~+e~- →π~+π~-(γ) crosssection with the initial state radiation method at BABAR

We present a precise BABAR measurement on the cross section of the process e+e-→π+π-(γ) from threshold to an energy of 3 GeV with the initial state radiation(ISR) technique,using 232 fb-1 of data collected with the BABAR detector at e+e-center-of-mass energies near 10.58 GeV.The ISR luminosity is determined from a study of the leptonic process e+e-→μ+μ-γ(γ).The leading-order hadronic contribution to the muon magnetic anomaly calculated using the ππ cross section measured from threshold to 1.8 GeV is(514.1±2.2(stat)±3.1(syst))×10-10.     

KLOE results on light mesons

The KLOE collaboration has recently published new results concerning scalar and pseudoscalar mesons.Here the φ→ a 0 (980)γ→ηπ 0 γ decay analysis and the search for the φ→ K 0 K 0 γ decay are discussed,together with the η→π + π-e + edecay measurements annd the new results for the pseudoscalar mixing angle and gluonium content of the η’ meson.     

Observation of the decay B- → D(s)((*)+) K- ℓ- ν(ℓ)

We report the observation of the decay B- → D(s)((*)+) K- ?- ν(?) based on 342 fb(-1) of data collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e+ e- storage rings at SLAC. A simultaneous fit to three D(s)(+) decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B- → D(s)((*)+) K- ?- ν(?) with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B- → D(s)((*)+) K- ?- ν(?)) = [6.13(-1.03)(+1.04)(stat)±0.43(syst)±0.51(B(D(s)))]×10(-4), where the last error reflects the limited knowledge of the D(s) branching fractions.     

Measurement of the Cabibbo-Kobayashi-Maskawa angle gamma in B+/--->D*K+/- decays with a Dalitz analysis of D-->K0(S)pi-pi+

We report on a measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase gamma through a Dalitz analysis of neutral D decays to K0(S)pi-pi+ in the processes B+/- -->D*K+/-, D*-->Dpi0, Dgamma. Using a sample of 227 x 10(6) BB pairs collected by the BABAR detector, we measure the amplitude ratios r(B)=0.12+/-0.03+/-0.04 and r*(B)=0.17+/-0.10+/-0.03+/-0.03, the relative strong phases delta(B)=(104+/-45(+17+16)(-21-24))degrees and delta*(B)=(-64+/-41(+14)(-12)+/-15) degrees between the amplitudes A(B- -->D*0K-) and A(B- -->D*0)K-), and gamma=(70+/-31(+12+14)(-10-11))degrees. The first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the Dalitz model uncertainty. The results for the strong and weak phases have a twofold ambiguity.     

Ds1(2536)+ decays and the structure of P-wave charmed strange mesons

We calculate the D s 1 (2536) + decays into D*K channels,including the decay D s 1 (2536) + → D + π-K + through a virtual D*0 in a constituent quark model.Widths and S/D amplitudes ratio are in agreement with the recent Belle and BABAR data,being the results sensitive to 1 P 1 and 3 P 1 mixture.     

Measurement of the wrong-sign decays D0 --> K+ pi- pi0 and D0 --> K+ pi- pi+ pi-, and search for CP violation

Using 281 fb-1 of data from the Belle experiment recorded at or near the (4S) resonance, we have measured the rates of the "wrong-sign" decays D0 --> K+ pi- pi0 and D0 --> K+ pi- pi+ pi- relative to those of the Cabibbo-favored decays D0 --> K- pi+ pi0 and D0 --> K- pi+ pi+ pi-. These wrong-sign decays proceed via a doubly Cabibbo-suppressed amplitude or via D0-D0 mixing; the latter has not yet been observed. We obtain R(WS)(K pi pi0) = [0.229 +/- 0.015(stat)(+0.013)(-0.009)(syst)]% and R(WS)(K3pi) = [0.320 +/- 0.018(stat)(+0.018)(0.013)(syst)]%. The CP asymmetries are measured to be -0.006 +/- 0.053 and -0.018 +/- 0.044 for the K+ pi- pi0 and K+ pi- pi+ pi- final states, respectively.     

Search for D0-D(-)0 mixing and a measurement of the doubly Cabibbo-suppressed decay rate in D0-->Kpi decays

We present results of a search for D0-D(-)0 mixing and a measurement of R(D), the ratio of doubly Cabibbo-suppressed decays to Cabibbo-favored decays, using D0-->K+pi- decays from 57.1 fb(-1) of data collected near sqrt[s]=10.6 GeV with the BABAR detector at the PEP-II collider. At the 95% confidence level, allowing for CP violation, we find the mixing parameters x('2)<0.0022 and -0.056相似文献   

Production of the exotic 1(--) hadrons ϕ(2170), X(4260), and Y(b)(10890) at the LHC and Tevatron via the Drell-Yan mechanism

We calculate the Drell-Yan production cross sections and differential distributions in the transverse momentum and rapidity of the J(PC) = 1(--) exotic hadrons ?(2170), X(4260), and Y(b)(10890) at the LHC and the Tevatron. These hadrons are tetraquark (four-quark) candidates, with a hidden ss, cc, and bb quark pair, respectively. In deriving the distributions, we include the order α(s) QCD corrections, resum the large logarithms in the small transverse momentum region in the impact-parameter formalism, and use the state of the art parton distribution functions. Production rates for the processes pp(p) → ?(2170)× (→ ?(1020)π+ π- → K+ K- π+ π-) +…, pp(p) → X(4260)(→J/ψπ+ π- → μ+ μ- π+ π-)+…, and pp(p) → Y(b)(10890)(→ Υ(1S,2S,3S)π+ π- → μ+ μ- π+ π-) +… are presented. Their measurements will help in understanding the dynamics of these exotic hadrons.     

Measurement of the Time-Dependent CP Asymmetry in B;{0}-->D_{CP};{(*)}h;{0} Decays

We report a measurement of the time-dependent CP-asymmetry parameters S and C in color-suppressed B{0}-->D{(*)0}h{0} decays, where h{0} is a pi{0}, eta, or omega meson, and the decays to one of the CP eigenstates K+K-, K{S}{0}pi{0}, or K{S}{0}omega. The data sample consists of 383 x 10{6} Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The results are S=-0.56+/-0.23+/-0.05 and C=-0.23+/-0.16+/-0.04, where the first error is statistical and the second is systematic.     

Measurements of CP-violating asymmetries in the decay B0-->K+K-K0

We analyze the decay B0-->K+K-K0 using 383 x 10(6) BB events collected by the BABAR detector at SLAC to extract CP violation parameter values over the Dalitz plot. Combining all K+K-K0 events, we find ACP=-0.015+/-0.077+/-0.053 and beta eff = 0.352+/-0.076+/-0.026 rad, corresponding to a CP violation significance of 4.8 sigma. A second solution near pi/2-beta eff is disfavored with a significance of 4.5 sigma. We also report ACP and beta eff separately for decays to phi(1020)K0, f0(980)K0, and K+K-K0 with mK+K- > 1.1 GeV/c2.     

Method for determining the D0-D0 mixing parameters

We propose a new method to determine the mass and width differences of the two D meson mass eigenstates as well as the CP violating parameters associated with D0-D[over ]0 mixing. We show that an accurate measurement of all the mixing parameters is possible for an arbitrary CP violating phase, by combining observables from a time dependent study of D decays to a doubly Cabibbo suppressed mode with information from a CP eigenstate. As an example we consider D0-->K*0pi0 decays where the K*0 is reconstructed in both K+pi- and K(S)pi0. We also show that decays to the CP eigenstate D-->K+K- together with D-->K+pi- decays can be used to extract all the mixing parameters. There is a fourfold ambiguity in the solutions for x and y in both the cases. A combined analysis using D0-->K*0pi0 and D-->K+K- can also be used to reduce the ambiguity in the determination of parameters.     

Observation of B(s)(0) → J/ψf(2)'(1525) in J/ψK+ K- final states

The decay B(s)(0) → J/ψK+ K- is investigated using 0.16 fb(-1) of data collected with the LHCb detector using 7 TeV pp collisions. Although the J/ψ? channel is well known, final states at higher K+ K- masses have not previously been studied. In the K+ K- mass spectrum we observe a significant signal in the f(2)'(1525) region as well as a nonresonant component. After subtracting the nonresonant component, we find B(B(s)(0) → J/ψf(2)'(1525))/B(B(s)(0) → J/ψ?) = (26.4 ± 2.7 ± 2.4)%.     

New results on the hadronic vacuum polarization contribution to the muon g-2

Results on the lowest-order hadronic vacuum polarization contribution to the muon magnetic anomaly are presented.They are based on the latest published experimental data used as input to the dispersion integral.Thus recent results on τ→ντππ0 decays from Belle and on e+e-annihilation to π+π-from BABAR and KLOE are included.The new data,together with improved isospin-breaking corrections for τ decays,result into a much better consistency among the different results.A discrepancy between the Standard Model prediction and the direct g-2 measurement is found at the level of 3σ.     

Supersymmetric contributions to BS→K-π+ decay

Recently, the CDF Collaboration has measured the branching fraction and time-integrated direct CP asymmetry of BS→K-π+ decay. The branching ratio is lower than the previous predictions based on QCD factorization. The experimental results favor a large CP asymmetry in BS→K-π+ decay while the standard model prediction is very small. We compute the supersymmetry contributions to BS→K-π+ decay using the mass insertion method, and find that the LR and RL mass insertions could suppress this branching ratio and increase this direct CP asymmetry well in line with the experimental data.