Download or read book Fortegnelse over de i 1821 indskrevne Studenter written by and published by . This book was released on with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Time Dependent CP Asymmetry in Neutral B Decays to J psi pi written by and published by . This book was released on 2003 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present the first study of the time-dependent CP-violating asymmetry in B° 2!J/[psi][pi]° decays using ee− annihilation data collected with the BABAR detector at the [Upsilon](4S) resonance during the years 1999-2002 at the PEP-II asymmetric-energy B Factor at SLAC. Using approximately 88 million B{bar B} pairs, the results for the coefficients of the cosine and sine terms of the CP asymmetry are C{sub J/{psi}[pi]°} = 0.38 ± 0.41 (stat) ± 0.09 (syst) and S{sub J/{psi}[pi]°} = 0.05 ± 0.49 (stat) ± 0.16 (syst).
Download or read book BRANCHING FRACTION AND TIME DEPENDENT CP ASYMMETRY IN NEUTRAL B DECAYS TO PSI AND A NEUTRAL PION written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The invariance of physical laws under the combination of exchange of particles with antiparticles (charge conjugation, C) and reversal of coordinates (parity, P) is called CP symmetry. The violation of CP symmetry was first discovered in 1964 in the neutral kaon system, and is in general one of the great puzzles of particle physics. The recent observation of CP violation in the B meson system has been a simultaneous success for model predictions and experiment. The opportunity now exists to probe details of the underlying mechanisms. This thesis presents measurements of the branching fraction and time-dependent CP-violating asymmetry in neutral B decays to J/[psi][pi][sup 0]. The decay amplitude for this channel features both tree and penguin diagram contributions, the interference of which can yield a result for the asymmetry differing from that found in the ''golden mode'' B[sup 0][yields] J/[psi] K[sub s][sup 0]. Using the measured branching fraction and CP asymmetry, constraints are placed on the ratio of penguin to tree amplitudes in B[sup 0][yields] J/[psi][pi][sup 0]. In addition, the impact on the CP asymmetry measurement in B[sup 0][yields] J/[psi] K[sub s][sup 0] is discussed. The results are presented for e[sup+]e[sup -] annihilation data collected with the BABAR detector on the[Upsilon](4S) resonance at the PEP-II asymmetric-energy B Factory at SLAC. The measurement of the branching fraction, based on about 23 million B[bar B] pairs collected between October 1999 and October 2000, yields BF(B[sup 0][yields] J/[psi][pi][sup 0])= (2.0[+-] 0.6 (stat)[+-] 0.2(syst)) x 10[sup -5]. With about 88 million B[bar B] pairs collected during the years 1999-2002, our results for the coefficients of the cosine and sine terms of the CP asymmetry are C[sub J/[psi][pi][sup 0]]= 0.38[+-] 0.41 (stat)[+-] 0.09 (syst) and S[sub J/[psi][pi][sup 0]]= 0.05[+-] 0.49 (stat)[+-] 0.16 (syst).
Download or read book Time Dependent CP Violation Measurements written by Markus Röhrken and published by Springer Science & Business Media. This book was released on 2013-10-17 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a high-quality, high-precision method for the data analysis of an interesting elementary particle reaction. The data was collected at the Japanese B-meson factory KEKB with the Belle detector, one of the most successful large-scale experiments worldwide. CP violation is a subtle quantum effect that makes the world look different when simultaneously left and right and matter and antimatter are exchanged. This being a prerequisite for our own world to have developed from the big bang, there are only a few experimental indications of such effects, and their detection requires very intricate techniques. The discovery of CP violation in B meson decays garnered Kobayashi and Maskawa, who had predicted these findings as early as 1973, the 2008 Nobel prize in physics. This thesis describes in great detail what are by far the best measurements of branching ratios and CP violation parameters in two special reactions with two charm mesons in the final state. It presents an in-depth but accessible overview of the theory, phenomenology, experimental setup, data collection, Monte Carlo simulations, (blind) statistical data analysis, and systematic uncertainty studies.
Download or read book Study of Time dependent CP Asymmetries with Partial Reconstruction of B D pi written by and published by . This book was released on 2003 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a preliminary measurement of the time-dependent CP asymmetries in decays of neutral B mesons to the final states D*{sup {-+}}[pi]{sup ±}, using approximately 82 million B{bar B} events collected by the BABAR experiment at the PEP-II storage ring. Events containing these decays are selected with a partial reconstruction technique, in which only the high momentum [pi]{sup ±} and the low momentum pion from the D*{sup {-+}} decay are reconstructed. The flavor of the other B meson in the event is tagged using the information from kaon and lepton candidates. They measure the time-dependent CP asymmetry [Alpha] = -0.063 {+-} 0.024 (stat.) {+-} 0.017 (syst.). They interpret these results in terms of the angles of the unitarity triangle to set a bound on
Download or read book A Study of Time Dependent CP Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon 4S written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb[sup -1] recorded at the[Upsilon](4S) resonance and 3.9 fb[sup -1] off-resonance. One of the neutral B mesons, which are produced in pairs at the[Upsilon](4S), is fully reconstructed in the CP decay modes J/[psi] K[sub S][sup 0], [psi](2S) K[sub S][sup 0], [chi][sub c1] K[sub S][sup 0], J/[psi] K*[sup 0] (K*[sup 0][yields] K[sub S][sup 0][pi][sup 0]) and J/[psi] K[sub L][sup 0], or in flavor-eigenstate modes involving D(*)[pi]/[rho]/[sub 1] and J/[psi] K*[sup 0] (K*[sup 0][yields] K[sup+][pi][sup -]). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B[sup 0]-[bar B][sup 0] oscillation frequency[Delta]m[sub d]are measured with a sample of about 6350 fully-reconstructed B[sup 0] decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds[Delta]m[sub d]= 0.516[+-] 0.016 (stat)[+-] 0.010 (syst) ps[sup -1]. The value of the asymmetry amplitude sin2[beta] is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B[sup 0] decays in the CP-eigenstate modes. We find sin2[beta]= 0.59[+-] 0.14 (stat)[+-] 0.05 (syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter[lambda]= 0.93[+-] 0.09 (stat)[+-] 0.03 (syst), which is consistent with the expectation of[lambda]= 1 for no direct CP violation.
Download or read book Measurement of Time dependent CP Asymmetry in the Decay of a Neutral B Meson to a J Psi and a Long lived Neutral Kaon at BABAR written by Emilie Claire Mutsumi Martin and published by . This book was released on 2009 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: The BABAR experiment at the SLAC National Accelerator Laboratory provides an excellent environment to study CP violation in B decays. A measurement of time-dependent CP-violating asymmetry in neutral B decays to charmonium states, in particular B0, B¯ 0 → J/psi K0L , is presented here. J/psi K0L is the most compelling CP-even final state used to measure the Unitarity Triangle parameter sin2beta at BABAR. The measurements reported here use a data sample of (465 +/- 5) million Upsilon(4 S) → BB¯ decays collected with the BABAR detector at the PEP-II asymmetric energy e +e- storage operating at the SLAC National Accelerator Laboratory. The time-dependent CP asymmetry parameters measured for the B0 → J/psi K0L decay are: C = -0.033 +/- 0.050(stat) +/- 0.027(syst) and S = -0.694 +/- 0.061(stat) +/- 0.031(syst). These results are in good agreement with the Standard Model predictions.
Download or read book Measurement of Time Dependent CP Asymmetry in the Decay of a Neutral B Meson to a J Psi and a Long Lived Neutral Kaon at BaBar written by and published by . This book was released on 2013 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brief discours sur aucunes actions des Estats G n raulx des Pays Bas s avoir sur le faict de la n gociation de paix apr s la surprise du chasteau ville de Namur l entretiennement de la pacification de Gand la puissante arm e written by and published by . This book was released on 1579 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of CP Violation in B Mesons Using the BABAR Detector written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results on time-dependent CP asymmetries in neutral B decays. The measurements use a data sample of about 88 million[Upsilon](4S)[yields] B[bar B] decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We study events in which one neutral B meson is fully reconstructed in a final state and the other B meson is determined to be either a B[sup 0] or[bar B][sup 0] from its decay products. Final states considered include B[sup 0][yields] J/[psi]K[sub S][sup 0], B[sup 0][yields] J/[psi]K[sub L][sup 0], B[sup 0][yields] J/[psi][pi][sup 0], B[sup 0][yields] D*[sup+] D*[sup -], B[sup 0][yields][phi]K[sub S][sup 0], B[sup 0][yields][pi][sup+][pi][sup -], and B[sup 0][yields][rho][sup[+-]][pi][sup[-+]].
Download or read book Time Dependent Cp Violation Measurements written by Markus Rohrken and published by . This book was released on 2013-10-31 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Branching Fraction and Time dependent CP Asymmetry in Neutral B Decays to PSI and a Neutral Pion written by Aron L. Soha and published by . This book was released on 2003 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observation of CP Violation in the Neutral B Meson System written by and published by . This book was released on 2004 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of about 88 million [Upsilon](4S) 2!B{bar B} decays collected between 1999 and 2002. We study events in which one neutral B meson decay to the CP-eigenstates J/[psi] K{sub S}°, [psi](2S)K{sub S}°, [chi]{sub c1}K{sub S}°, and [eta]{sub c}K{sub S}°, or to flavor-eigenstates involving D{sup (*)}[pi]/[rho]/a1 and J/[psi]K*°(K*° 2!K [pi]−), is fully reconstructed. The flavor of the other neutral B meson is tagged at the time of its decay, mainly using the charge of identified leptons and kaons. The proper time elapsed between the meson decays is determined by measuring the distance between the decay vertices. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2[beta], is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor- and CP-eigenstate samples. We measure sin2[beta] = 0.755 ± 0.074 (stat) ± 0.030 (syst).
Download or read book A Study of Factorization and a Measurement of CP Violation written by and published by . This book was released on 2006 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a study of the decay $\bar{B}$0 2!D*+ [omega][pi]- with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B0$\bar{B}$0 decays collected between 1999 and 2004, we measure the branching fraction [beta]}($\bar{B}$0 2!D*+ [omega][pi]- ) = (2.88 ± 0.21(stat.) ± 0.31(syst.)) x 10-3. We study the invariant mass spectrum of the [omega][pi]- system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in [tau]- 2![omega][pi]- v[tau]. We also measure the polarization of the D*+ as a function of the [omega][pi]- mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*+ to be [Gamma]L/[Gamma] = 0.654 ± 0.042(stat.) ± 0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as $\bar{B}$0 2!D*+ [rho](1450)-, [rho](1450)- 2![omega][pi]-. Furthermore, we present the results on the time-dependent CP asymmetry in neutral B meson decays to the CP eigenstate J/[Psi]KL. The measurements use a data sample of about 88 million Y(4S) 2!B$\bar{B}$ decays collected between 1999 and 2002 with the BABAR detector. We study events in which one neutral B meson is fully reconstructed in the J/[Psi]KL final state and the other B meson is determined to be either a B0 or a $\bar{B}$0 from its decay products. The amplitude of the CP asymmetry, which in the Standard Model is proportional to sin 2[beta], is derived from the decay-time distributions in such events. We measure sin 2[beta] = 0.723 ± 0.158(stat.) ± 0.086(syst.), which is consistent with Standard Model expectations.
Download or read book A Study of Time dependent CP violating Asymmetries in B0 J psiK0S and B0 psi 2S K0S Decays written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a preliminary measurement of time-dependent CP-violating asymmetries in B° → J/[psi] K{sub S}° and B° → [psi](2S)K{sub S}° decays recorded by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The data sample consists of 9.0 fb−1 collected at the [Upsilon](4S) resonance and 0.8 fb−1 off-resonance. One of the neutral B mesons, produced in pairs at the [Upsilon](4S), is fully reconstructed. The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The time difference between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities and the time resolution function are measured with samples of fully-reconstructed semileptonic and hadronic neutral B final states. The value of the asymmetry amplitude, sin2[beta], is determined from a maximum likelihood fit to the time distribution of 120 tagged B° → J/[psi] K{sub S}° and B° → [psi](2S) K{sub S}° candidates to be sin2[beta] = 0.12 ± 0.37(stat) ± 0.09(syst) (preliminary).
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).
