CP Violation in the D0 -] Pi+ Pi- Decay at CDF.

CP Violation in the D0 -] Pi+ Pi- Decay at CDF. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
We report a measurement of the CP violating asymmetry in D° →??− decays using approximately 215,000 decays reconstructed in about 5.94 fb−1 of CDF data. We use the strong D*+ → D°?+ decay ('D* tag') to identify the flavor of the charmed meson at production time and exploit CP-conserving strong c{bar c} pair-production in p{bar p} collisions. Higher statistic samples of Cabibbo-favored D° → K−?+ decays with and without D* tag are used to highly suppress systematic uncertainties due to detector effects. The result, A{sub CP}(D° →?+?−) = [0.22 ± 0.24 (stat.) ± 0.11 (syst.)]%, is the world's most precise measurement to date and it is fully consistent with no CP violation.

CP Violation in the D0 -] Pi+ Pi- Decay at CDF.

CP Violation in the D0 -] Pi+ Pi- Decay at CDF. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
We report a measurement of the CP violating asymmetry in D° →??− decays using approximately 215,000 decays reconstructed in about 5.94 fb−1 of CDF data. We use the strong D*+ → D°?+ decay ('D* tag') to identify the flavor of the charmed meson at production time and exploit CP-conserving strong c{bar c} pair-production in p{bar p} collisions. Higher statistic samples of Cabibbo-favored D° → K−?+ decays with and without D* tag are used to highly suppress systematic uncertainties due to detector effects. The result, A{sub CP}(D° →?+?−) = [0.22 ± 0.24 (stat.) ± 0.11 (syst.)]%, is the world's most precise measurement to date and it is fully consistent with no CP violation.

Search for CP Violation in $D^0 \to H^+h^-$ Decays at CDF.

Search for CP Violation in $D^0 \to H^+h^-$ Decays at CDF. PDF Author:
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ISBN:
Category :
Languages : en
Pages :

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Book Description
I report on a measurement of \CP-violating asymmetries ($A_{\Gamma}$) between effective lifetimes of $D^0$ or $\bar{D}^0$ in fully reconstructed $D^0\to K^+ K^-$ and $D^0\to \pi^+\pi^-$ decays collected in $p\bar{p}$ collisions by the Collider Detector at Fermilab experiment. The full CDF data set corresponding to $9.7$ fb$^{-1}$ of integrated luminosity is used. The flavor of the charm meson at production is determined by exploiting the strong-interaction decay $D^{*+} \to D^0 \pi^+$, while the contamination from mesons originated in $b$-hadron decays is evaluated and subtracted from the sample. Signal yields as functions of the observed decay-time distributions are extracted from maximum likelihood fits and used to measure the asymmetries. The results, $A_\Gamma (K^+K^- ) = \bigl( -1.9 \pm 1.5 \mathrm{(stat)} \pm 0.4 \mathrm{(syst)} \bigr)\times10^{-3}$ and $A_\Gamma (\pi^+\pi^- )= \bigl( -0.1 \pm 1.8 \mathrm{(stat)} \pm 0.3 \mathrm{(syst)} \bigr)\times10^{-3}$, and their combination, $A_\Gamma = \bigl( -1.2 \pm 1.2\bigr)\times10^{-3}$, are consistent with the SM predictions and other experimental determinations.

Precision Measurement of CP Violation in $D0̂\to\pi+̂\pi-̂$ at CDF.

Precision Measurement of CP Violation in $D0̂\to\pi+̂\pi-̂$ at CDF. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6

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Book Description
We report a preliminary measurement of the CP violating asymmetry in D° →??− using approximately 215,000 decays reconstructed in about 5.94/fb of CDF data. We use the strong D* ± D°?+ decay (D* tag) to identify the flavor of the charmed meson at production time and exploit CP-conserving strong c-{bar c} pair-production in p-{bar p} collisions. Higher statistic samples of Cabibbo-favored D° → K−?+ decays with and without D* tag are used to highly suppress systematic uncertainties due to detector effects. The result is the world's most precise measurement to date.

Searches for CP Violation in Charmed Meson Decays

Searches for CP Violation in Charmed Meson Decays PDF Author: Hamish Gordon
Publisher: Springer
ISBN: 3319070673
Category : Science
Languages : en
Pages : 167

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Book Description
Our current understanding of the fundamental building blocks of the Universe, summarised by the Standard Model of particle physics, is incomplete. For example, it fails to explain why we do not see equal, or almost equal, numbers of particles and their antiparticle partners. To explain this asymmetry requires, among other effects, a mechanism known as charge-parity (CP) violation that causes differences between the rates at which particles and antiparticles decay. CP violation is seen in systems containing bottom and strange quarks, but not in those with up, charm or top quarks. This thesis describes searches for particle-antiparticle asymmetries in the decay rates of charmed mesons. No evidence of CP violation is found. With current sensitivities, an asymmetry large enough to observe probably could not be explained by the Standard Model. Instead an explanation could come from new physics, for example contributions from supersymmetric or other undiscovered heavy particles. In the thesis, the development of new techniques to search for these asymmetries is described. They are applied to data from the LHCb experiment at CERN to make precise measurements of asymmetries in the D^+->K^-K^+pi^+ decay channel. This is the most promising charged D decay for CP violation searches.

Measurement of Partial Widths and Search for Direct CP Violation in D0 Meson Decays to K- K+ and Pi- Pi

Measurement of Partial Widths and Search for Direct CP Violation in D0 Meson Decays to K- K+ and Pi- Pi PDF Author:
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ISBN:
Category :
Languages : en
Pages : 7

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Book Description
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.

Measurement of CP-Violating Asymmetries in $D^0 \to \pi^+ \pi^-$ and $D^0 \to K^+ K^- $ Decays at CDF.

Measurement of CP-Violating Asymmetries in $D^0 \to \pi^+ \pi^-$ and $D^0 \to K^+ K^- $ Decays at CDF. PDF Author:
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ISBN:
Category :
Languages : en
Pages :

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Book Description
We report a search for non-Standard Model physics through the measurement of CP-violating asymmetries in the singly-Cabibbo- suppressed $D^0 \to \pi^+ \pi^-$ and $D^0 \to K^+ K^- $ decays reconstructed in about 5.9 fb-1 of CDF data. We use the strong $D^{*+} \to D^0\pi^+$ decay ("D tag") to identify the flavor of the charmed meson at production time and exploit CP-conserving strong cc pair-production in pp collisions. Large samples of Cabibbo-favored $D^0 \to K^-\pi^+$ decays with and without D tag are used to highly suppress systematic uncertainties due to detector effects. The results are the world's most precise measurements to date and have been published by Physical Review D in January 2012 [1].

Measurement of CP-violating Asymmetries in the D0 - [pi]+ [pi]- and D0 - K+ K- Decays at CDF

Measurement of CP-violating Asymmetries in the D0 - [pi]+ [pi]- and D0 - K+ K- Decays at CDF PDF Author: Angelo Di Canto
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


CP Violation in {B_s}^0 -> J/psi.phi Decays

CP Violation in {B_s}^0 -> J/psi.phi Decays PDF Author: Sabato Leo
Publisher: Springer
ISBN: 3319079298
Category : Science
Languages : en
Pages : 146

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Book Description
This thesis reports on the final measurement of the flavor-mixing phase in decays of strange-bottom mesons (B_s) into J/psi and phi mesons performed in high-energy proton-antiproton collisions recorded by the Collider Experiment at Fermilab. Interference occurs between direct decays and decays following virtual particle-antiparticle transitions (B_s-antiB_s). The phase difference between transition amplitudes (“mixing phase”) is observable and extremely sensitive to contributions from non-standard-model particles or interactions that may be very hard to detect otherwise – a fact that makes the precise measurement of the B_s mixing phase one of the most important goals of particle physics. The results presented include a precise determination of the mixing phase and a suite of other important supplementary results. All measurements are among the most precise available from a single experiment and provide significantly improved constraints on the phenomenology of new particles and interactions.

Time-Dependent CP Violation Measurements

Time-Dependent CP Violation Measurements PDF Author: Markus Röhrken
Publisher: Springer Science & Business Media
ISBN: 3319007262
Category : Science
Languages : en
Pages : 205

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Book Description
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.

B Decays

B Decays PDF Author: Sheldon Stone
Publisher: World Scientific
ISBN: 9789810218362
Category : Science
Languages : en
Pages : 676

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Book Description
This 2nd edition is an extensive update of "B Decays?. The revisions are necessary because of the extensive amount of new data and new theoretical ideas. This book reviews what is known about b-quark decays and also looks at what can be learned in the future.The importance of this research area is increasing, as evidenced by the approval of the luminosity upgrade for CESR and the asymmetric B factories at SLAC and KEK, and the possibility of experiments at hadron colliders.The key experimental observations made thus far, measurement of the lifetimes of the different B species, B0-B0 mixing, the discovery of ?Penguin? mediated decays, and the extraction of the CKM matrix elements Vub and Vcb from semileptonic decays, as well as more mundane results, are described in great detail by the experimentalists who have been closely involved with making the measurements. Theoretical progress in understanding b-quark decays using HQET and lattice gauge techniques are described by theorists who have developed and used these techniques.Synthesizing the experimental and theoretical information, several articles discuss the implications for the ?Standard Model? and how further tests can be done using measurements of CP violation in the B system.