Download or read book Measurement of Direct CP Asymmetry in B pm to J psi K pm Decays Produced in p bar p Collisions at sqrt s written by and published by . This book was released on 2011 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of direct CP asymmetry is performed using 6fb-1 of p$\bar{p}$ collisions at √s = 1.96TeV from the CDF detector at the Fermi National Accelerator Laboratory. Approximately 80,000 B- → J/ K- (and charge conjugate) events were selected on the dimuon trigger and the yields were determined using a simultaneous mass and lifetime fit. After corrections, a measurement of ACP = 0.0034 ± 0.0043(stat.) ± 0.0060(syst.) is obtained, which is consistent with the SM prediction and previous measurements at DØ and the B factories.

Download or read book Study of Direct CP Violation in B J psi K pi File Decays written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a search for direct CP violation in B{sup ±} 2!J/[psi]K{sup ±}[pi]{sup ±} decays. The event sample is selected from 2.8 fb−1 of p{bar p} collisions recorded by D0 experiment in Run II of the Fermilab Tevatron Collider. The charge asymmetry A{sub CP}(B 2!J/[psi]K) = +0.0075 ± 0.0061(stat.) {+-} 0.0027(syst.) is obtained using a sample of approximately 40 thousand B{sup {+-}} 2!J/[psi]K{sup {+-}} decays. The achieved precision is of the same level as the expected deviation predicted by some extensions of the standard model. They also measured the charge asymmetry A{sub CP}(B+ 2!J/[psi][pi]+) = -0.09 {+-} 0.08(stat.){+-}0.03(syst.).

Download or read book Measurement of the Branching Fraction And Search for Direct CP Violation in the B J Psi Pi Decay Mode at BaBar written by Francesco Fobozzi and published by . This book was released on 2006 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenomenon of CP-violation in weak interactions, discovered in 1964 in decays of neutral kaons, receives a simple and elegant explanation in the Standard Model with three generations of quarks. Indeed, in this model the common source of CP-asymmetry phenomena is represented by a simple complex phase in the unitary matrix (the Cabibbo-Kobayashi-Maskawa matrix) describing the charged weak couplings of the quarks. This simple scheme has never received an accurate validation, because the phenomenological parameters determined from measurements of CP-violation in kaons decays are related to the fundamental parameters of the theory in a complex way, sensitive to large theoretical uncertainties. On the contrary, decays of neutral B mesons like B{sup 0} {yields} J/{psi} K{sub S}{sup 0} represent a unique laboratory to test the predictions of the theory because they are expected to show significant CP-violation effects, the magnitude of which is cleanly related to the Standard Model parameters. Thus experimental facilities have been built with the purpose of performing extensive studies of B decays. The BABAR experiment is operating at one of these facilities, at the Stanford Linear Accelerator Center. It is collecting data at the PEP-II asymmetric e{sup +}e{sup -} collider (E{sub e{sup -}} = 9.0 GeV; E{sub e{sup +}} = 3.1 GeV), a high-luminosity accelerator machine (L = 3 x 10{sup 33} cm{sup -2}s{sup -1}). The center-of-mass energy (10.58 GeV) of the e{sup +}e{sup -} system at PEP-II allows resonant production of the {Upsilon}(4S), a b{bar b} bound state, which decays almost exclusively in a B{sup 0}{bar B}{sup 0} or a B{sup +}B{sup -} pair. A high-acceptance detector, projected and built by a wide international collaboration, detects and characterizes the decay products of the B mesons. From the analysis of the data collected during the first two years of operation, the BABAR collaboration has established CP-violation in decays of neutral B mesons at the 4.1{sigma} level. Besides the primary goal of CP-violation studies, the high luminosity of PEP-II, coupled with the high acceptance of the BABAR detector, allows competitive studies of the properties of a wide set of B decay modes. In particular, measurements of non-leptonic decays are extremely useful to understand the dynamics of the non-perturbative strong interactions involved in these processes. In this thesis a study of the non-leptonic decay mode B{sup {+-}} {yields} J/{psi}{pi}{sup {+-}} is presented.

Download or read book Lifetime Difference and CP Asymmetry in the Bs J psi Phi Decay written by and published by . This book was released on 2007 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The B{sub s} meson is an interesting particle to study because a sizable mixing induced CP violation in the B{sub s} -- {bar B}{sub s} system would be an indication for physics beyond the Standard Model. In this paper we present a measurement of the lifetime difference [Delta][Gamma] between the B{sub s} mass eigenstates and the CP violating phase in the decay B{sub s} → J/[psi][phi]. In 1.7 fb−1 of data collected with the CDF II detector at the Tevatron p{bar p} collider we measure [Delta][Gamma] = 0.076{sup +0.059}{sub -0.063} (stat.) ±0.006 (syst.) ps−1, well consistent with the Standard Model prediction, and a mean B{sub s} lifetime of c{sub tau}{sub s} = 456 ± 13 (stat.) ± (syst.) [mu]m. We find no evidence for CP violation.

Download or read book Update of Time Dependent CP Asymmetry Measurements in B to C cbar s Decays written by and published by . This book was released on 2008 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present updated measurements of time-dependent CP asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of (465 ± 5) x 106 [Upsilon](4S) → B{bar B} decays collected with the BABAR detector at the PEP-II B factory. The time-dependent CP asymmetry parameters measured from J/[psi]K{sub S}°, J/[psi]K{sub L}°, [psi](2S)K{sub S}°, [chi]{sub c1}K{sub S}°, [eta]{sub c}K{sub S}°, and J/[psi]K*° decays are: (1) C{sub f} = 0.026 ± 0.020(stat) ± 0.016(syst); and (2) S{sub f} = 0.691 ± 0.029(stat) ± 0.014(syst).

Download or read book Measurement of the Direct CP Asymmetry in B S Gamma Decays written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe a measurement of the direct CP asymmetry between inclusive b [yields] s[gamma] and [bar b] [yields] [bar s][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 89 million B[bar B] pairs recorded with the BABAR detector at PEP-II, from which we reconstruct a set of 12 exclusive b [yields] s[gamma] final states containing one charged or neutral kaon and one to three pions. We measure an asymmetry of A[sub CP] (b [yields] s[gamma]) = 0.025 [+-] 0.050(stat.) [+-] 0.015(syst.), corresponding to an allowed range of -0.06

Download or read book Measurement of the Direct CP Violating Charge Asymmetry in B pm rightarrow mu pm nu mu D 0 Decays written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the first measurement of the CP violating charge asymmetry in $B^\pm \to \mu^\pm \nu_\mu {D}^0$ decays using the full Run II integrated luminosity of 10.4 fb$^{-1}$ in proton-antiproton collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure a difference in the yield of $B^-$ and $B^+$ mesons in these decays by fitting the reconstructed invariant mass distributions. This results in an asymmetry of $A^{\mu D^{0}} =\left[-0.03 \pm 0.27 \right]\%$, which is consistent with standard model predictions.

Download or read book Measurement of the CP Violation Parameter Sin 2 beta in B sup 0 r arrow J psi K sub S sup 0 Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A sample of[approximately] 400 B[sub d][sup 0]/[bar B][sub d][sup 0][r-arrow] J/[psi]K[sub s][sup 0] decays collected in[bar p]p collisions by the CDF detector is used to directly measure the CP-violation parameter sin (2[beta]). They find sin(2[beta])= 0.79[sub[minus]0.44][sup+ 0.41], favoring the standard model expectation of a large CP violation in this B[sup 0] decay mode.

Download or read book Measurement of the Cp Asymmetry in Semimuonic B Decays Produced in Ppbar Collision at S 1 2 written by and published by . This book was released on 2007 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors measure the asymmetry between positive and negative same-sign muon pairs originating from semileptonic decays of pairs of B hadrons. Low transverse momentum dimuon pairs are evaluated to determine B hadron content using a log likelihood fit to two-dimensional impact parameter significance templates. Corrections are made for asymmetries arising from the detector, trigger, and hadrons which are reconstructed as muons. Using 1.1 million muon pairs from data corresponding to an integrated luminosity of 1.6 fb−1, they find 210,000 same-sign muon pairs with both muon candidates coming from B decays. After corrections, they measure a semileptonic asymmetry from neutral B mixing of A{sub SL} = 0.0080 ± 0.0090(stat) ± 0.0068(syst). This asymmetry can be interpreted as a constraint on the complex phase of the CKM matrix element V{sub ts} by using the B° neutral mixing contribution measured at the B factories. They measure the CP violating asymmetry from B{sub s} mixing to be A{sub SL}{sup s} = 0.020 ± 0.028.

Download or read book Measurement of the CP Violating Phase Beta s in B0s J Psi Phi Decays with the CDF II Detector written by and published by . This book was released on 2012 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the \CP-violating parameter \betas using approximately 6500 $\BsJpsiPhi$ decays reconstructed with the CDF\, II detector in a sample of $p\bar p$ collisions at $\sqrt{s}=1.96$ TeV corresponding to 5.2 fb${̂-1}$ integrated luminosity produced by the Tevatron Collider at Fermilab. We find the \CP-violating phase to be within the range $\betas \in [0.02, 0.52] \cup [1.08, 1.55]$ at 68% confidence level where the coverage property of the quoted interval is guaranteed using a frequentist statistical analysis. This result is in agreement with the standard model expectation at the level of about one Gaussian standard deviation. We consider the inclusion of a potential $S$-wave contribution to the $\Bs\to J/\psi K+̂K-̂$ final state which is found to be negligible over the mass interval $1.009

Download or read book Measurement of the CP Asymmetry Parameter Sin 2 beta at CDF written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the time-dependent asymmetry in the rate for {bar B}{sub d}° versus B{sub d}° decays to J/[psi]K{sub S}°. In the context of the Standard Model this is interpreted as a measurement of the CP-violation parameter sin(2[beta]). A total of 198 ± 17 B{sub d}°/{bar B}{sub d}° decays were observed in p{bar p} collisions at √s = 1.8 TeV by the CDF detector at the Fermilab Tevatron. The initial b-flavor is determined by a same side flavor tagging technique. Our analysis results in sin(2[beta]) = 1.8 ± 1.1(stat) ± 0.3(syst).

Download or read book Measurement of Direct CP Violation Parameters in B pm to J psi K pm and B pm to J psi pi pm Decays with 10 4 Fb 1 of Tevatron Data written by and published by . This book was released on 2013 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of CP Asymmetries in B0 Ks Pi0 Pi0 Decays written by J. C. Chen and published by . This book was released on 2005 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a preliminary measurement of the time-dependent CP asymmetry for the neutral B-meson decay into the CP = +1 final state K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}, with K{sub S}{sup 0} {yields} {pi}{sup +}{pi}{sup -} and {pi}{sup 0} {yields} {gamma}{gamma}. They use a sample of approximately 227 million B-meson pairs recorded at the {Upsilon}(4S) resonance by the BABAR detector at the PEP-II B-Factory at SLAC. From a maximum likelihood fit they extract the mixing-induced CP-violation parameter S{sub K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}} = 0.84 {+-} 0.71(stat) {+-} 0.08(syst) and the direct CP-violation parameter C{sub K{sub S}{sup 0}}{pi}{sup 0}{pi}{sup 0} = 0.27 {+-} 0.52(stat) {+-} 0.13(syst), where the first uncertainty is statistical and the second systematic.

Download or read book Measurement of the CP Violating Phase Beta s in B s J psi Phi Decays written by and published by . This book was released on 2010 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: The CP violating phase [beta] j/[Psi][Phi]s is measured in decays of B0s → J/[Psi][Phi]. This measurement uses 5.2 fb-1 of data collected in √s = 1.96 TeV p$\bar{p}$ collisions at the Fermilab Tevatron with the CDF Run-II detector. CP violation in the Bs0-$\bar{B}$s0 system is predicted to be very small in the Standard Model. However, several theories beyond the Standard Model allow enhancements to this quantity by heavier, New Physics particles entering second order weak mixing box diagrams. Previous measurements have hinted at a deviation from the Standard Model expectation value for [beta]sJ/[Psi][Phi] with a significance of approximately 2[sigma]. The measurement described in this thesis uses the highest statistics sample available to date in the Bs0 → J/[Psi][Phi] decay channel, where J/[Psi] → [mu]+[mu]- and [Phi] → K+K-. Furthermore, it contains several improvements over previous analyses, such as enhanced signal selection, fully calibrated particle ID and flavour tagging, and the inclusion of an additional decay component in the likelihood function. The added decay component considers S-wave states of KK pairs in the Bs0 → J/[Psi] K+K- channel. The results are presented as 2-dimensional frequentist confidence regions for [beta]sJ/[Psi][Phi] and [Delta][Gamma] (the width difference between the Bs0 mass eigenstates), and as a confidence interval for [beta]sJ/[Psi][Phi] of [0.02,0.52] U [1.08, 1.55] at the 68% confidence level. The measurement of the CP violating phase obtained in this thesis is complemented by the world's most precise measurement of the lifetime [tau]s = 1.53 ± 0.025 (stat.) ± 0.012 (syst.) ps and decay width difference [Delta][Gamma] = 0.075 ± 0.035 (stat.) ± 0.01 (syst.) ps-1 of the Bs0 meson, with the assumption of no CP violation.

Download or read book Measurement of Time Dependent CP Asymmetry in B0 ccbar K 0 Decays written by and published by . This book was released on 2009 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present updated measurements of time-dependent Cp asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of (465 ± 5) x 106 [Upsilon](4S) 2!B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric energy ee− storage rings operating at the SLAC National Accelerator Laboratory. The time-dependent CP asymmetry parameters measured from J/[psi] K{sub S}°, J/[psi]K{sub L}°, [psi](2S)K{sub S}°, [eta]{sub c}K{sub S}°, [chi]{sub c1}K{sub S}° and J/[psi] K*(892)° decays are: C{sub f} = 0.024 ± 0.020(stat) ± 0.016(syst) and -[eta]{sub f}S{sub f} = 0.687 ± 0.028(stat) ± 0.012(syst).

Download or read book Measurements of the Branching Fraction and Time Dependent CP Asymmetries of B0 to J Psi Pi0 Decays written by K. George and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present measurements of the branching fraction and time-dependent CP asymmetries in B{sup 0} {yields} J/{psi}{pi}{sup 0} decays based on (231.8 {+-} 2.6) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We obtain a branching fraction {Beta}(B{sup 0} {yields} J/{psi}{pi}{sup 0}) = (1.94 {+-} 0.22 (stat) {+-} 0.17 (syst)) x 10{sup -5}. We also measure the CP asymmetry parameters C = -0.21 {+-} 0.26 (stat) {+-} 0.06 (syst) and S = -0.68 {+-} 0.30 (stat) {+-} 0.04 (syst).

Download or read book Measurement of Partial Widths and Search for Direct CP Violation in D0 Meson Decays to K K and Pi Pi written by and published by . This book was released on 2004 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of relative partial widths and decay rate CP asymmetries in K−K and?−?+ decays of D° mesons produced in p{bar p} collisions at √s = 1.96 TeV. They use a sample of 2 x 105 D*+ → D°?+ (and charge conjugate) decays with the D° decaying to K−?+, K−K+, and?−?+, corresponding to 123 pb−1 of data collected by the CDF II experiment at the Fermilab Tevatron collider. No significant direct CP violation is observed, they measure?(D° → K−K+)/?(D° → K−?+) = 0.0992 ± 0.0011 ± 0.0012,?(D° →?−?+)/?(D° → K−?+) = 0.03594 ± 0.00054 ± 0.00040,?(D° → K−K+)/?(D° →?−?+) = 2.760 ± 0.040 ± 0.034, A{sub CP} (K−K+) = (2.0 ± 1.2 ± 0.6)%, and A{sub CP}(?−?+) = (1.0 ± 1.3 ± 0.6)%, where, in all cases, the first uncertainty is statistical and the second is systematic.