Download or read book A Search for CP Violation in Xi Xi and Lambda Lambda Hyperon Decays written by Timothy Kenneth Holmstrom and published by . This book was released on 2003 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for CP Violation in Charged Xi and Lambda Hyperon Decays written by and published by . This book was released on 2004 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have compared the p and {bar p} angular distributions in 117 million ?− → ??− → p?−?− and 41 million ?+ → {bar ?}?+ → {bar p}?+?+ decays using a subset of the data from the HyperCP experiment (ES71) at Fermilab. They find no evidence of CP violation, with the direct-CP-violating parameter A{sub ??} {triple_bond} (a{sub ?}a{sub ?} - {bar a}{sub ?}{bar a}{sub ?})/(a{sub ?}a{sub ?} + {bar a}{sub ?}{bar a}{sub ?}) = [0.0 ± 5.1(stat) ± 4.4(syst)] x 10−4.
Download or read book Search for CP Violation in Hyperon Decays written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct CP violation in nonleptonic hyperon decays can be established by comparing the decays of hyperons and anti-hyperons. For[Xi] decay to[Lambda][pi] followed by[Lambda] to p[pi], the proton distribution in the rest frame of Lambda is governed by the product of the decay parameters[alpha][sub[Xi]][alpha][sub[Lambda]]. The asymmetry A[sub[Xi][Lambda]], proportional to the difference of[alpha][sub[Xi]][alpha][sub[Lambda]] of the hyperon and anti-hyperon decays, vanishes if CP is conserved. We report on an analysis of a fraction of 1997 and 1999 data collected by the Hyper CP (E871) collaboration during the fixed-target runs at Fermilab. The preliminary measurement of the asymmetry is[Alpha][sub[Xi][Lambda]]=[-7[+-] 12(stat)[+-] 6.2(sys)] x 10[sup -4], an order of magnitude better than the present limit.
Download or read book Particle Physics CP Violation in Hyperon Decays written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary research activities under this grant were in E871 (HyperCP) at Fermilab, a search for CP violation in hyperon decays which completed data taking in January, 2000. HyperCP is an experiment designed to perform a sensitive search for direct CP violation in the decays of cascade ([Xi]) and[Lambda] hyperons by looking for an asymmetry between particle and antiparticle decay parameters. The experiment is expected to achieve a sensitivity[approx]10[sup -4] in the decay parameters. Standard model predictions for this CP-violating asymmetry range from 0.3 to 5 x 10[sup -4]. A difference between the decay parameters for particle and antiparticle is direct evidence that CP symmetry is violated. A non-zero asymmetry would be the first evidence for CP violation outside of the K[sup o] system. Recent results from KTeV indicate a direct CP violation in K[sup o] decays, which suggests that CP violation will appear in other decays. In addition, we will look at a number of rare hyperon decays involving muons. These probe important new physics topics such as Majorana neutrinos and lepton number violating processes. The latter are of great current interest because new evidence for neutrino oscillations indicate lepton flavor violation does occur. Our data will lead to an improvement in the limits on branching ratios for these processes typically by three to four orders-of-magnitude. The muon detector construction and data resulting from it have been the responsibility of the Michigan group. We are now leading the analysis of the rare muon-related decay modes, and were responsible for the muon system and beam monitor upgrades for the 1999 run.
Download or read book Search for CP Viloation in Xi and Lambda Hyperon Decays written by Chad J. Materniak and published by . This book was released on 2009 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Examining CP Symmetry in Strange Baryon Decay written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-conservation of CP symmetry can manifest itself in non-lepton ichyperon decays as a difference in the decay parameter between the strange-baryon decay and its charge conjugate. By comparing the decay distribution in the[Lambda] helicity frame for the decay sequence[Xi][sup -][yields][Lambda][pi][sup -], [Lambda][yields] p[pi][sup -] with that of[bar[Xi]][sup+] decay, E756 at Fermilab did not observe any CP-odd effect at the 10[sup -2] level. The status of a follow-up experiment, HyperCP (FNAL E871), to search for CP violation in charged[Xi]-[Lambda] decay with a sensitivity of 10[sup -4] is also presented.
Download or read book Cp Violation written by Cecilia Jarlskog and published by World Scientific. This book was released on 1989-01-01 with total page 733 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents:CP Phenomenology:Introduction to CP Violation (C Jarlskog)CP-Violation in the K0-K0-System (K Kleinknecht)The Quark Mixing Matrix, Charm Decays and B Decays (S Stone)The Question of CP Noninvariance — As Seen through the Eyes of Neutral Beauty (I I Bigi et al.)In Search of CP Noninvariance in Heavy Quark Systems (L-L Chau)CP Violation at High Energy e+e- Colliders (J Bernabéu & M B Gavela)CP Violation in the Standard Model with Four Families (A Datta & E A Paschos)CP Effects When Neutrinos are their Own Antiparticles (B Kayser)On Spontaneous CP Violation Triggered by Scalar Bosons (I I Bigi & A I Sanda)CP Violation and Left-Right Symmetry (R N Mohapatra)CP Violation and Supersymmetry (R N Mohapatra)Electric Dipole Moments (S M Barr & W H Marciano)Special Topics: The Strong CP Problem (R D Peccei)CP Violation and Cosmology (P Langacker)Nonleptonic Interactions:The 1/N Approach to Nonleptonic Weak Interactions (A J Buras)Chiral Perturbation Theory Approach to Weak Amplitudes (E de Rafael)What We Learnt from Weak Decays of Heavy Quarks (B Stech)Weak Hamiltonian on the Lattice (G Martinelli) Readership: High energy physicists. Keywords:CP Violation;Quark Mixing Matrix;Charm Decays;B Decays;Nonleptic Interactions;Heavy QuarksReview: “Similar material is most often available in journals, but the book accomplishes a valuable service in drawing it together … the one that will probably have the greatest utility and longest lifespan is the survey of B meson physics by I Bigi, V Khoze, N Uraltsev and A Sanda … Bigi et al. here provide the most thorough and readable account of the issues that I know of. I have seen no review comparable to the excellent summary of electric dipole moments by S Barr and W Marciano … the volume offers a generally readable entry into this field for a reader who has a basic background in particle physics.” John F Donoghue Science “… this book performs a very useful service for anyone active or interested in CP violation, both as a source of primary information and as a work of reference.” K J Peach J Phys. G: Nucl. Part. Phys.
Download or read book Measurement of Xi Polarization and Decay Parameters in Xi arrow lambda pi Decay written by Melin Huang and published by . This book was released on 2003 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Energy Physics Index written by and published by . This book was released on 1992 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CP Violation in B s 0 J psi phi Decays written by Sabato Leo and published by Springer. This book was released on 2014-07-24 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Search for CP Violation in B0 to D K0 Decays written by Troels C. Petersen and published by . This book was released on 2004 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following the idea of considering three-body decays with final state B to DKpi in the pursuit of the notoriously elusive unitary angle gamma, the initial steps towards its measurement are presented. Using a sample of approximately 88 million BBbar pairs collected with the BaBar detector at the PEP-II collider, a measurement of the branching fractions BO to D+- KO pi-+ and BO to D*+- KO pi-+ are presented for the entire Dalitz region: Br(BO to D+- KO pi-+) = (4.97 +- 0.69 +- 0.55) x 10^(-4) Br(BO to D*+- KO pi-+) = (3.00 +- 0.66 +- 0.29) x 10^(-4). In both decay modes the dominant resonance is the K*+-(892) between the neutral kaon and the charged pion. Measuring the branching fractions of the corresponding resonant two-body decays yields: Br(BO to D+- K*-+) = (4.78 +- 0.58 +- 0.53) x 10^(-4) Br(BO to D*+- K*-+) = (3.22 +- 0.59 +- 0.29) x 10^(-4). Performing a time-dependent CP asymmetries fit of the resonant decay mode BO to D+- K*-+ yields: C = 0.93 +- 0.18 +- 0.03 ABS[lambda] = 0.19 +- 0.25 +- 0.04 S = 0.18 +- 0.28 +- 0.02 Delta S = 0.08 +- 0.28 +- 0.02. As the amplitude ratio ABS[lambda] is consistant with zero, no interference sensitive to gamma can be established at this point.
Download or read book Current Experiments in Elementary Particle Physics written by and published by . This book was released on 1985 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observation of CP Violation in B DK Decays written by Paolo Gandini and published by Springer. This book was released on 2016-08-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: CP violation is a well-established phenomenon in particle physics, but until 2001 it was only observed in kaons. In the last decade, several matter-antimatter asymmetries have been observed in neutral B mesons in line with the expectations of the Standard Model of the weak interaction. Direct CP violation is also expected in the decay rates of charged B+ mesons versus that of B- mesons, though the greatest effects are present in a decay that occurs just twice in 10 million decays. Such rarity requires huge samples to study and this is exactly what the LHC, and its dedicated B-physics experiment LHCb provide. This thesis presents an analysis of the first two years of LHCb data. The author describes the first observation of the rare decay, B- → DK-, D → π-K+ and the first observation of direct CP violation in this B decay. The work constitutes essential information on the experiment’s measurement of a fundamental parameter of the theory and stands as a benchmark against which subsequent analyses of this type will be compared.
Download or read book Studies of CP Violation in Charmless Three Body b Hadron Decays written by Daniel O'Hanlon and published by Springer. This book was released on 2018-11-02 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights two essential analyses of data collected during the LHCb experiment, based on the Large Hadron Collider at CERN. The first comprises the first observation and studies of matter-antimatter asymmetries in two three-body b-baryon decays, paving the way for more precise measurements of the relatively unknown decay properties of b-baryon decays. The second is an analysis of a charged B meson decay to three charged pions, where previously large matter-antimatter asymmetries were observed in a model-independent analysis. Here a model of the decay amplitude is constructed using the unitarity-conserving ‘K-matrix’ model for the scalar contributions, so as to gain an understanding of how the previously observed matter-antimatter asymmetries arise; further, the model’s construction yields the most precise and comprehensive study of this decay mode to date.
Download or read book Measurement of CP Violation Parameter A sub CP in Weak Decays of Charmed Baryons Lambda sub C with the Belle Detector written by Peter Smerkol and published by . This book was released on 2013 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Searches for CP Violation in Charmed Meson Decays written by Hamish Gordon and published by Springer. This book was released on 2014-06-07 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Search for Direct CP Violation in K pi pi pi Decays written by Woon-Seng Choong and published by . This book was released on 2000 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
