Observation of the Decay B=> J/psi eta K and Search for X(3872)=> J/psi eta

We report the observation of the $B$ meson decay $B^\pm\to J/\psi \eta K^\pm$ and evidence for the decay $B^0\to J/\psi \eta K^0_S$, using {90} million $BBbar$ events collected at the \ensuremath{\Upsilon{(4S)}}\xspace resonance with the $BaBar$ detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. We obtain branching fractions of $\cal{B}$$(B^\pm\to J/\psi \eta K^{\pm}$)=$(10.8\pm 2.3(\rm{stat.})\pm 2.4(\rm{syst.}))\times 10^{-5}$ and $\cal{B}$$(B^0\to J/\psi\eta K_{\rm{S}}^{0}$)=$(8.4\pm 2.6(\rm{stat.})\pm 2.7(\rm{syst.}))\times 10^{-5}$. We search for the new narrow mass state, the X(3872), recently reported by the Belle Collaboration, in the decay B^\pm\to X(3872)K^\pm, X(3872)\to \jpsi \eta and determine an upper limit of $\cal{B}$(B^\pm \to X(3872) K^\pm \to \jpsi \eta K^\pm) $<7.7\times 10^{-6}$ at 90% C.L.Comment: 7 pages and two figures, submitted to Phys. Rev. Lett

Measurement of time-dependent CP asymmetries in B-0 -> D-(*)+/-pi(-/+) decays and constraints on sin(2 beta+gamma)

We present a measurement of CP-violating asymmetries in fully reconstructed B-0-->D((*)+/-)pi(-/+) decays in approximately 88x10(6) Y(4S)-->B (B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum-likelihood fit we obtain the following for the CP-violating parameters: a=-0.022+/-0.038 (stat)+/-0.020 (syst), a(*)=-0.068+/-0.038 (stat)+/-0.020 (syst), c(lep)=+0.025+/-0.068 (stat)+/-0.033 (syst), and c(lep)(*)=+0.031+/-0.070 (stat)+/-0.033 (syst). Using other measurements and theoretical assumptions we interpret the results in terms of the angles of the Cabibbo-Kobayashi-Maskawa unitarity triangle, and find parallel tosin(2beta+gamma)parallel to>0.69 at 68% confidence level. We exclude the hypothesis of no CP violation [sin(2beta+gamma)=0] at 83% confidence level

Observation of e(+)e(-) annihilation into the C=+1 hadronic final states rho(0)rho(0) and phi rho(0)

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Observation of the decay B ---> J psi eta K and search for X(3872) ---> J / pxi eta

We report the observation of the B meson decay B±→J/ψηK± and evidence for the decay B0→J/ψηKS0, using 90×10^6 BB̅ events collected at the Υ(4S) resonance with the BABAR detector at the SLAC PEP-II e+e- asymmetric-energy storage ring. We obtain branching fractions of B(B±→J/ψηK±)=[10.8±2.3(stat)±2.4(syst)]×10-5 and B(B0→J/ψηKS0)=[8.4±2.6(stat)±2.7(syst)]×10-5. We search for the new narrow mass state, the X(3872), recently reported by the Belle Collaboration, in the decay B±→X(3872)K±,X(3872)→J/ψη and determine an upper limit of B[B±→X(3872)K±→J/ψηK±]<7.7×10-6 at 90% confidence level

Measurement of the Direct CP Asymmetry in b→sγ Decays

We describe a measurement of the direct CP asymmetry between inclusive b→sγ and b̅ →s̅ γ decays. This asymmetry is expected to be less than 0.01 in the standard model, but could be enhanced up to about 0.10 by new physics contributions. We use a sample of 89×106 BB̅ pairs recorded with the BABAR detector at SLAC PEP-II, from which we reconstruct a set of 12 exclusive b→sγ final states containing one charged or neutral kaon and one to three pions. We measure an asymmetry of ACP(b→sγ)=0.025±0.050(stat)±0.015(syst), corresponding to an allowed range of -0.06<ACP(b→sγ)<+0.11 at 90% confidence level

Measurement of the direct CP asymmetry in b -> s gamma decays

We describe a measurement of the direct CP asymmetry between inclusive b-->sgamma and (b) over bar -->(s) over bar gamma decays. This asymmetry is expected to be less than 0.01 in the standard model, but could be enhanced up to about 0.10 by new physics contributions. We use a sample of 89x10(6) B (B) over bar pairs recorded with the BABAR detector at SLAC PEP-II, from which we reconstruct a set of 12 exclusive b-->sgamma final states containing one charged or neutral kaon and one to three pions. We measure an asymmetry of A(CP)(b-->sgamma)=0.025+/-0.050(stat)+/-0.015(syst), corresponding to an allowed range of -0.06sgamma)<+0.11 at 90% confidence level. RI Patrignani, Claudia/C-5223-2009; Lista, Luca/C-5719-2008; Bellini, Fabio/D-1055-2009; crosetti, nanni/H-3040-2011; Roe, Natalie/A-8798-2012; Neri, Nicola/G-3991-2012; Monge, Maria Roberta/G-9127-2012; Sarti, Alessio/I-2833-201

Study of B+- ---> J / psi pi+- and B+- ---> J / psi K+- decays: Measurement of the ratio of branching fractions and search for direct CP violation

We study B+/--->J/psipi(+/-) and B+/--->J/psiK(+/-) decays in a sample of about 89x10(6) B (B) over bar pairs collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. We observe a signal of 244+/-20 B+/--->J/psipi(+/-) events and determine the ratio B(B+/--->J/psipi(+/-))/B(B+/--->J/psiK(+/-)) to be [5.37+/-0.45(stat)+/-0.11(syst)]%. The charge asymmetries for the B+/--->J/psipi(+/-) and B+/--->J/psiK(+/-) decays are determined to be A(pi)=0.123+/-0.085(stat)+/-0.004(syst) and A(K)=0.030+/-0.015(stat)+/-0.006(syst), respectively

Measurement of the Time-Dependent CP Asymmetry in the B0→ϕK0 Decay

We present a measurement of the time-dependent CP asymmetry for the neutral B-meson decay B0→ϕK0. We use a sample of approximately 114×106 B-meson pairs taken at the Υ(4S) resonance with the BABAR detector at the PEP-II B-meson factory at SLAC. We reconstruct the CP eigenstates ϕKS0 and ϕKL0, where ϕ→K+K-, KS0→π+π-, and KL0 is observed via its hadronic interactions. The other B meson in the event is tagged as either a B0 or B̅ 0 from its decay products. The values of the CP-violation parameters are SϕK=0.47±0.34(stat)-0.06+0.08(syst) and CϕK=0.01±0.33(stat)±0.10(syst)

Search for the rare leptonic decay B+ ---> mu+ nu(mu)

We have performed a search for the rare leptonic decay B+-->mu(+)nu(mu) with data collected at the Y(4S) resonance by the BABAR experiment at the PEP-II storage ring. In a sample of 88.4x10(6) B (B) over bar pairs, we find no significant evidence for a signal and set an upper limit on the branching fraction B(B+-->mu(+)nu(mu))<6.6x10(-6) at the 90% confidence level

Measurement of the direct CP asymmetry in b -> s gamma decays

We describe a measurement of the direct CP asymmetry between inclusive b-->sgamma and (b) over bar -->(s) over bar gamma decays. This asymmetry is expected to be less than 0.01 in the standard model, but could be enhanced up to about 0.10 by new physics contributions. We use a sample of 89x10(6) B (B) over bar pairs recorded with the BABAR detector at SLAC PEP-II, from which we reconstruct a set of 12 exclusive b-->sgamma final states containing one charged or neutral kaon and one to three pions. We measure an asymmetry of A(CP)(b-->sgamma)=0.025+/-0.050(stat)+/-0.015(syst), corresponding to an allowed range of -0.06sgamma)<+0.11 at 90% confidence level. RI Patrignani, Claudia/C-5223-2009; Lista, Luca/C-5719-2008; Bellini, Fabio/D-1055-2009; crosetti, nanni/H-3040-2011; Roe, Natalie/A-8798-2012; Neri, Nicola/G-3991-2012; Monge, Maria Roberta/G-9127-2012; Sarti, Alessio/I-2833-201