Measurement of CP observables in B± → D(⁎)K± and B± → D(⁎)π± decays

Measurements of CP observables in B ± →D (⁎) K ± and B ± →D (⁎) π ± decays are presented, where D (⁎) indicates a neutral D or D ⁎ meson that is an admixture of D (⁎)0 and D¯ (⁎)0 states. Decays of the D ⁎ meson to the Dπ 0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ± π ∓ , K + K − and π + π − final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb −1 taken at centre-of-mass energies of s=7, 8 and 13 TeV, respectively. The study of B ± →D ⁎ K ± and B ± →D ⁎ π ± decays using a partial reconstruction method is the first of its kind, while the measurement of B ± →DK ± and B ± →Dπ ± decays is an update of previous LHCb measurements. The B ± →DK ± results are the most precise to date

First observation of forward Z→bbˉZ \rightarrow b \bar{b} production in pppp collisions at s=8\sqrt{s}=8 TeV

The decay Z→bb¯ is reconstructed in pp collision data, corresponding to 2 fb −1 of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of s=8 TeV. The product of the Z production cross-section and the Z→bb¯ branching fraction is measured for candidates in the fiducial region defined by two particle-level b -quark jets with pseudorapidities in the range 2.220 GeV and dijet invariant mass in the range 4520$GeV and dijet invariant mass in the range$45 < m_{jj} < 165$GeV. From a signal yield of$5462 \pm 763$$Z \rightarrow b \bar{b}$events, where the uncertainty is statistical, a production cross-section times branching fraction of$332 \pm 46 \pm 59$pb is obtained, where the first uncertainty is statistical and the second systematic. The measured significance of the signal yield is 6.0 standard deviations. This measurement represents the first observation of the$Z \rightarrow b \bar{b}$production in the forward region of$pp$ collisions

Study of the doubly charmed tetraquark T+cc

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed

Flowering Time

Adaptation genes have a major role to play in the response of plants to environmental changes. Flowering time is a key adaptive trait, responding to environmental and endogenous signals that ensure reproductive growth and devel- opment occurs under favorable environmental conditions. Under a climate change scenario, temperature and water conditions are forecast to change and/or fluctuate, while photoperiods will remain constant at any given latitude. By assessing the current knowledge of the flowering-time pathways in both model (Arabidopsis thaliana) and key cereal (rice, barley, wheat, maize), temperate forage and biofuel grasses (perennial ryegrass, Miscanthus, sugarcane), root (sugar beet), and tree (poplar) crop species, it is possible to define key breeding targets for promoting adaptation and yield stability under future climatic conditions. In Arabidopsis, there are four pathways controlling flowering time, and the genetic and/or epigenetic control of many of the steps in these pathways has been well characterized. Despite A.R. Bentley • I.J. Mackay • E. Mutasa-Go ¨ttgens • J. Cockram (*) The John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge CB3 0LE, UK e-mail: [email protected] E.F. Jensen • I.P. Armstead • C. Hayes • D. Thorogood • A. Lovatt Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth SY23 3EB, UK H. Ho ¨nicka • M. Fladung Johann Heinrich von Thu ¨nen Institute, Institute of Forest Genetics, Sieker Landstr. 2, 22927 Grosshansdorf, Germany K. Hori • M. Yano National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan J.E. Mullet Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA R. Morris • N. Pullen Computational and Systems Biology Department, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK C. Kole (ed.), Genomics and Breeding for Climate-Resilient Crops, Vol. 2, DOI 10.1007/978-3-642-37048-9_1, © Springer-Verlag Berlin Heidelberg 2013 1 this, even in this model species, there is little published information on the molecu- lar basis of adaptation to the environment. In contrast, in crop and tree species, flowering time has been continually selected, either directly or indirectly as breeders and growers have selected the material that best suits a particular location. Understanding the genetic basis of this adaptive selection is now being facilitated via cloning of major genes, the mapping of QTL, and the use of marker-assisted breeding for specific flowering targets. In crop species where the genetic basis of flowering is not well understood (i.e., in the emerging biofuel grass, Miscanthus), such work is in its infancy. In cases where the genetic basis is well established, however, there are still grounds for important discovery, via new and emerging methods for mapping and selecting for flowering-time traits (i.e., QTL mapping in MAGIC populations, RABID selection), as well as methods for creating new genetic combinations with potentially novel flowering-time phenotypes (i.e., via targeted mutagenesis). In the future it is likely that computational modeling approaches which incorporate gene networks and the range of phenological response to measurable environmental conditions will play a central role in predicting the resilience of crop and tree species under climate change scenarios.Peer reviewe