Search

We present a detailed study of charged-current quasielastic (anti)neutrino scattering cross sections on a 12C target obtained using a spectral function S (p, ε) that gives a scaling function in accordance with the electron scattering data. The spectral function accounts for the nucleon-nucleon (NN) correlations, it has a realistic energy dependence and natural orbitals (NO’s) from the Jastrow correlation method are used in its construction. The results are compared with those when NN correlations are not included, namely harmonic-oscillator single-particle wave functions are used instead of NO’s. A comparison of the results with recent experiments, as well as to results from the superscaling approach is done. The contribution of two-particle two-hole meson-exchange currents on neutrino–nucleus interactions is also considered within a fully relativistic Fermi gas. The results show a good agreement with the experimental data over the whole range of neutrino energies. [ABSTRACT FROM AUTHOR]

The Joint Physics Analysis Center is a collaboration between theorists and experimentalists working in hadronic physics. In order to facilitate the exchange of information between the different actors in hadron spectroscopy, we have created an interactive website. In this note, I summarize the first projects available on the website. [ABSTRACT FROM AUTHOR]

The JLAB upgrade will soon be completed and the new CLAS12 detector system will collect large volumes of data allowing detailed investigations of many aspects of hadron physics. The focus of the MesonEx experiment is on the production of mesonic states by low Q2 virtual photons, or quasi-real photons. Studying such mesonic states is a particularly challenging data analysis problem, requiring well understood detector systems, clean signal and background separation, handling of large volumes of data and crucially a close collaboration between experimentalists and theorists to ensure the most sophisticated theoretical methods are used to interrogate the data. Here we briefly outline some of the analysis and methods that are being used to prepare for the MesonEx experiment. [ABSTRACT FROM AUTHOR]

We have investigated the decays of B¯0 → K¯*0R and B¯0s → ϕR with R being the X(4160), Y(3940), Z(3930) and a predicted J = 1 resonances. By using a model in which these states are dynamically generated from the vector-vector interaction, most notably the D* D¯* and D*s D¯*s states, we predicted five ratios for the production of these states. Some ratios show that the resonance is built from cc¯ with or without extra hadronization. In order to offer some extra test for the molecular composition of these states, we have evaluated the invariant mass distributions for the B¯0s → ϕD*D¯* and B¯0s → ϕD*s D¯*sclose to threshold and made predictions for these magnitudes relative to the width for the production of the resonances. [ABSTRACT FROM AUTHOR]

The Laura++ software package is designed for performing fits of amplitude models to data from decays of spin-0 particles into final states containing three spin-0 particles--so-called Dalitz-plot analysis. An overview of the amplitude formalism and its software implementation is given as well as summaries of recently added features and planned future developments. [ABSTRACT FROM AUTHOR]

Charm and charmonium physics have gained renewed interest in the past decade. Recent spectroscopic observations strongly motivate these studies. Among the several possible reactions, measurements in proton-antiproton annihilation play an important role, complementary to the studies performed at B-factories. The fixed target P¯ANDA experiment at FAIR (Darmstadt, Germany) will investigate fundamental questions of hadron and nuclear physics in the interactions of antiprotons with nucleons and nuclei. With reaction rates as large as 2×107 interactions/s, and a mass resolution 20 times better as compared with the most recent B-factories, P¯ANDA is in a privileged position to successfully perform the measurement of the width of narrow states, such as the X(3872). P¯ANDA will investigate also high spin particles, whose observation was forbidden at B-factories, i.e. F-wave charmonium states. In this report extrapolations on cross sections and rates with P¯ANDA are given. [ABSTRACT FROM AUTHOR]

The BESIII Experiment at the Beijing Electron Positron Collider has accumulated the world's largest samples of e+e- collisions in the tau-charm region. Many results in the light meson decays have been produced at BESIII based on large data sample of J/ψ. Recent results, including the observations of η(1405) → f0(980)π0, Y(2175) in J/ψ → ηφπ+π- decays and the hadronic and radiative decays of η/η' will be presented. [ABSTRACT FROM AUTHOR]

Many new excited states of D mesons have been discovered in the last few years, bringing renewed interest to heavy meson spectroscopy. In a series of publications, the LHCb collaboration has studied the properties of the D meson excited states using decays of B mesons into a D meson plus light hadrons. These results are reviewed in this paper. [ABSTRACT FROM AUTHOR]

Employing a new class of string theories we construct a family of S -matrix amplitudes that factorize over linear Regge trajectories, and that are good candidates to be asymptotically free, i.e. to lead to asymptotically-free correlation functions working out the LS Z formulae the other way around. In particular, we propose a candidate for a string solution of QCD with NF massless quarks in the large-N 't Hooft limit, for the glueball and meson spectrum, and for certain S -matrix amplitudes in the collinear limit. The solution extends to massive quarks of equal mass. [ABSTRACT FROM AUTHOR]

The ±c meson has been studied by ATLAS experiment in several exclusive channels containing a J/ψ. ATLAS results on ±c spectroscopy obtained in LHC runs with the centre of mass beam energies 7 and 8 TeV are presented. The results include observation of the ±c(2S ) state and study of the decays±c → J/ψD±s. [ABSTRACT FROM AUTHOR]

The spectrum of excited hadrons - mesons and baryons - serves as an excellent probe of quantum chromodynamics (QCD), the fundamental theory of the strong interaction. The strong coupling however makes QCD challenging. It confines quarks and breaks chiral symmetry, thus providing us with the world of light hadrons. Highly-excited hadronic states are sensitive to the details of quark confinement, which is only poorly understood within QCD. This is the regime of nonperturbative QCD and it is one of the key issues in hadronic physics to identify the corresponding internal degrees of freedom and how they relate to strong coupling QCD. The quark model suggests mesons are made of a constituent quark and an antiquark and baryons consist of three such quarks. QCD predicts other forms of matter. What is the role of glue? Resonances with large gluonic components are predicted as bound states by QCD. The lightest hybrid mesons with exotic quantum numbers are estimated to have masses in the range from 1 to 2 GeV/c2 and are well in reach of current experimental programs. At Jefferson Laboratory (JLab) and other facilities worldwide, the high-energy electron and photon beams present a remarkably clean probe of hadronic matter, providing an excellent microscope for examining atomic nuclei and the strong nuclear force. [ABSTRACT FROM AUTHOR]

The diquark is a system of two strongly correlated quarks. Obviously no free diquarks can exist, since they carry color. However they can theoretically form inside hadrons. While the actual possibility that two quarks can form stable bounds inside hadrons is still discussed, the use of a diquark effective degree of freedom can be very useful because it reduces the total number of states predicted and simplify the interactions inside hadrons. Here we present a possible application of the diquark to the tetraquark meson in the diquark-antidiquark limit. In this limit the tetraquark meson is composed of a diquark and an antidiquark. The complete set of states are constructed and a simple algebraic mass formula is applied in order to calculate the spectrum. [ABSTRACT FROM AUTHOR]

In the usual holographic approach to QCD, the meson spectrum is generated due to a non-trivial 5-dimensional background. We propose an alternative 5-dimensional scenario in which the spectrum emerges due to the coupling to a scalar field whose condensation is supposed to be dual to the formation of a gluon condensate and mimics the scale anomaly in QCD. The spectrum of model has a finite number of discrete states plus continuum and reveals a Regge-like behavior in the strong coupling regime. [ABSTRACT FROM AUTHOR]

Properties of some open and hidden charm exotic states which have been studied using the composite model are summarized. It is found that, their decay properties are consistent with the data and further data are necessary to discriminate the hadronic molecular interpretation from other interpretations. [ABSTRACT FROM AUTHOR]

A brief report of some recent experimental developments concerning the X, Y and Z charmoniumlike mesons states and other puzzling states from the BaBar, Belle, BESIII and CDF experiments is presented. [ABSTRACT FROM AUTHOR]

Pion exchange in S-wave between hadrons that are themselves in S-wave may result in strong physical effects. Previously it was conjectured that this dynamics could lead to deeply bound quasi-molecular states. More recent studies suggest that the dynamics will result in a large non-resonant background rather than in bound states. [ABSTRACT FROM AUTHOR]

We present a systematic and self-consistent analysis of four-quark charmonium states and applied it to study compact four-quark systems and meson-meson molecules. Our results are robust and should serve to clarify the situation of charmonium spectroscopy above the threshold production of charmed mesons. [ABSTRACT FROM AUTHOR]

The CLAS is a multipurpose, large acceptance magnetic spectrometer, instrumented with detector systems sensitive to charged and neutral particles. The experimental program at CLAS is aimed at furthering our understanding of hadronic and nuclear physics, through electron and photon scattering experiments, which cover a large range of topics, including meson and baryon spectroscopy, nucleon structure through elastic and deep inelastic scattering, nuclear transparency, nuclear correlations and nuclear structure. This talk will briefly describe the detector and the collaboration that uses it and will highlight some recent results. [ABSTRACT FROM AUTHOR]

The HyCLAS experiment at Jefferson Lab is a program to search for new and unusual mesons produced via photoproduction. The strangeonia sector is poorly known and a main component of this program is a search for new strangeonium states. The reaction γ p→p [lowercase_phi_synonym] η is an ideal channel to look for strangeonium states due to the strangeness content of both the [lowercase_phi_synonym] and η. The data was acquired at the JLAB CLAS facility using a 4–5.5 GeV tagged photon beam. The [lowercase_phi_synonym] meson is identified via the K+K- decay. The recoil proton is observed in the CLAS spectrometer and the η meson is identified through the missing mass. Also of interest is the search for strangeonia decaying to [lowercase_phi_synonym]π0 and [lowercase_phi_synonym]ω. These channels are OZI suppressed for qq mesons and an observation of a meson decaying to these channels would provide a strong evidence of mesons beyond qqā. Preliminary results describing the data quality, kinematics and dynamics will be shown. [ABSTRACT FROM AUTHOR]

Hadron spectroscopy is one of the main topics within the COMPASS experiment. Three production mechanisms are used to study exotic states and to search for glueballs: diffractive and central production with pions and protons using a liquid hydrogen target and diffraction and Primakoff reactions with pions impinging on nuclear targets. While the main data taking has been performed in 2008 and 2009, where the statistics of previous experiments has been boosted by a factor 10–100, early measurements with diffractive production on nuclear targets in 2004 have confirmed the existence of an exotic state at a mass around 1.6 GeV. In this paper we report on the final analysis of our 2004 data discussing the evidence for the exotic π(1600) and show first insights into the results of the analysis from 2008 data using various final states, thus demonstrating the data quality and potential of the COMPASS data set. [ABSTRACT FROM AUTHOR]

The Tevatron experiments have each accumulated about 6 fb-1 good data since the start of RUN II. This large dataset provided good opportunities for meson spectroscopy studies at the Tevatron. This article will cover the recent new Υ(nS) polarization studies as well as exotic meson spectroscopy studies. [ABSTRACT FROM AUTHOR]

We propose a new mechanism for the production of D-mesons at forward rapidities and demonstrate that the resulting transverse momentum spectra are strongly dependent on the behavior of the nucleon charm distribution function at large Bjorken x. Our results show clearly that the hypothesis of intrinsic charm can be tested in pp collisions at RHIC and LHC. [ABSTRACT FROM AUTHOR]

The method is presented which allows to identify hadronic molecules in the resonance spectrum. Applications to light scalar mesons are discussed. [ABSTRACT FROM AUTHOR]

I present a brief review of results obtained both in open and hidden charm spectroscopy, discussing the interpretation of DsJ(2860), DsJ(2700) and X(3872). [ABSTRACT FROM AUTHOR]

Understanding quark and gluon confinement in Quantum Chromodynamics is one of the main issue in hadronic physics. Electromagnetic probes, real and virtual photons, are a powerful tool to investigate how the QCD-partons manifest themselves in strong interaction at the energy scale of the nucleon mass (GeV). The CLAS Collaboration in Hall B at Jefferson Lab (USA) has a broad scientific program ranging from the static and dynamic properties of constituent quarks to the investigation of possible exotic baryon configurations. After a brief description of the CLAS detector, some selected results will be outlined showing the richness of this non-perturbative physics. [ABSTRACT FROM AUTHOR]

The COSY-11 collaboration has performed measurements of pp→ppη and pp→ppη′ reactions at the excess energy Q = 15.5 MeV. The determined pp and p—meson invariant mass distributions are used for comparative study of the interaction within proton—meson system. Presently we are finishing the analysis of the pp→ppη′ reaction and the resulted preliminary invariant mass distributions will be presented and compared to the theoretical predictions and to the corresponding spectra for the ppη system. [ABSTRACT FROM AUTHOR]

Studies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenological models for QCD such as the constituent quark model. However, QCD allows for a much richer spectrum of meson states which include extra states such as exotics, hybrids, multi-quarks, and glueballs. First discussion of the status of exotic meson searches is given followed by a discussion of plans at Jefferson Lab to double the energy of the machine to 12 GeV, which will allow us to access photoproduction of mesons in search for gluonic excited states. [ABSTRACT FROM AUTHOR]

A proposal to search for exotic mesons in photoproduction has been accepted for running at Thomas Jefferson National Accelerator Facility, using the CEBAF Large Acceptance Spectrometer in Hall B. This program will bolster previously-thin statistics in many photoproduction channels, primarily those with charged particles in the final state, as well as seeking to confirm earlier findings in neutral channels, if possible. The promise of the neutral 3π channel is discussed. In addition, the experiment seeks to study the spectrum of both exotic and ordinary strangeonia. Limitations of the CLAS detector for meson spectroscopy are discussed, as well as possible solutions to minimize such limitations. [ABSTRACT FROM AUTHOR]

The masses of S and P states, pseudoscalar and vector decay constants, leptonic, semileptonic decay widths of charm (D) and beauty (B) open flavour mesons have been computed in the framework of Coulomb and power potential of the form V(r) = -αcr+Arv. The results are compared with other theoretical as well as experimental results. [ABSTRACT FROM AUTHOR]

The decays of charmed mesons can provide valuable information about hadron physics and espectroscopy. D-meson hadronic decays proceed mainly through resonant intermediate states. To study these processes, amplitude analysis techniques have been widely used. Here we present some results on this subject coming from Fermilab experiments E791 and FOCUS. In particular, we present studies of the ππ and Kπ S-wave systems from 3- and 4-body D-meson decays. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Experimental data from the 2m propane bubble chamber have been analyzed for exotic baryon states search. A number of peculiarities were found in the effective mass spectra of: Λπ+(Σ*+(1382),PDG), Λp and Λpp subsystems. A few events detected on the photographs of the propane bubble chamber exposed to a 10 GeV/c proton beam, were interpreted as S=-2 H0 light(

Recent studies concerning charmed baryon spectroscopy, performed by the Belle collaboration, are briefly described. We report the first observation of two new baryons [cap_xi]cx(2980) and [cap_xi]cx(3077), a precise determination of the masses of [cap_xi]c(2645) and [cap_xi]c(2815), observation of the Λc(2940)+ and experimental constraints on the possible spin-parity of the Λc(2880)+. Observations of several exclusive decays of B mesons to the final states containing charmed baryons are also briefly presented. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

A survey of the experimental, phenomenological, and theoretical status of the new heavy mesons is presented. States discussed are the Bc, hc, η′c, Ds(2317), Ds(2460), Ds(2700), Ds(2860), X (3872), X (3940), Y (3940), Z (3930), and Y (4260). © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We review the status of exotic (non-conventional) spectroscopy in lattice QCD. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The scenario of heavy quark meson spectroscopy underwent recently a major revolution, after the observation of BABAR and CLEO, confirmed by BELLE, of DsJ L=1 excited states, and by further evidences by SELEX. These experimental results have cast doubts on the incarnations of the ideas of Heavy Quark Effective Theory in heavy quark spectroscopy. I shall review the status of experimental data, discuss implications and sketch an outlook. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We do meson spectroscopy by studying the behavior of S-matrix poles in the complex-energy plane, as a function of the coupling strength for 3P0 quark-pair creation. Thereto, a general formula for non-exotic hadron-hadron scattering involving arbitrary quark confinement is used, which can be applied to all flavors. We find two distinct types of poles, which we call confinement and continuum poles, respectively. Together, they suffice to understand the experimental meson spectrum. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We summarize some persistent problems in scalar spectroscopy and discuss what could be learned here from charmless B-decays. Recent experimental results are discussed in comparison with theoretical expectations: a simple model based on penguin dominance leads to various symmetry relations in good agreement with recent data; a factorisation approach yields absolute predictions of rates. For more details, see [1]. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Charm meson decay dynamics have been studied extensively over the last decade. Recently, B meson decay dynamics have also been analyzed. We describe the Dalitz-plot analysis technique which has been applied by many experiments to three-body D and B decays. We discuss results from the E791, FOCUS, CLEO, BABAR and BELLE experiments. These studies probe a variety of physics including charmless B-decay, doubly-Cabibbo suppressed decays, CP violation and T violation, the properties of established light mesons, charm spectroscopy and the properties of ππ, Kπ and KK S-wave states. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

RunII at Fermilab’s Tevatron is currently under way and has recently reached a total of 1 fb-1 of integrated luminosity delivered to each of its two experiments, CDF and DØ. Selected RunII preliminary results are reviewed, with emphasis on the spectroscopy and decays of heavy mesons with charm and beauty. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The status of several of the newly discovered heavy mesons is discussed. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

A combined analysis of new π0 and η photoproduction data from CB-ELSA collaboration was performed including the earlier data from SAID data base, new data on beam asymmetry from the GRAAL collaboration and data on γp → KΛ and KΣ. Three baryon resonances have a substantial coupling to ηN, the well known N(1535)S11, N(1720)P13 and the newly observed N(2070)D15 resonance. A new P11 state with mass 1840 MeV and width 140 MeV was observed contributing to most of the fitted reactions. The data also demand the presence of two D13 states at 1870 and 2170 MeV. The properties of observed states and their contributions to different observables are discussed. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We study the mass spectrum of baryons with two and three charmed quarks. For double charm baryons the spin splitting is found to be smaller than standard quark-model potential predictions. This splitting is not influenced either by the particular form of the confining potential or by the regularization taken for the contact term of the spin-spin potential. We consistently predict the spectra for triply charmed baryons. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We present a theoretical framework that accounts for the new DJ and DsJ mesons measured in the open-charm sector. These resonances are properly described if considered as a mixture of conventional P-wave quark-antiquark states and four-quark components. The narrowest states are basically P-wave quark-antiquark mesons, while the dominantly four-quark states are shifted above the corresponding two-meson threshold, being broad resonances. We study the electromagnetic decay widths as basic tools to scrutiny their nature. The proposed explanation incorporates in a natural way the most recently discovered mesons in charmonium espectroscopy. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

In this talk, I would review the new observation of X(1835), which has properties inconsistent with any know mesons, but consistent with expectations for the state that produces the strong pp mass threshold enhancement observed in the J/ψ → γpp process at BESII. I will also talk about some other multiquark candidates which are indicated by pΛ and K-Λ mass threshold enhancements. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Recent discovery of DsJ particles, which are considered to be a great trouble by experimentalists as well as theorists, had already been resolved by our potential model proposed some time ago by two of us (T.M. and T.M.), in which the Hamiltonian and wave functions are expanded in 1/(heavy quark mass) respecting heavy quark symmetry. Using our model, we explain how narrow states like DsJ can be realized, predict properties of 0+ and 1+ states of B and Bs heavy mesons, and interpret how global SU(3) symmetry seems to be recovered for these 0+ and 1+ heavy mesons. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The Babar experiment at the high luminosity storage ring PEP-II offers excellent opportunities in quarkonium spectroscopy. Recent Babar results obtained in this field are reported. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

At CLEO, charmonium spectroscopy is pursued both thorugh e+e- annihilation data taken in the Upsilon region and more recently at ψ(2S). A nmber of first observations (ηc′, hc, π and K form factors) have been made, and numerous high precision measurements have been made in radiative and hadronic decays of charmonium resonances. A brief report of these contributions is presented. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Results on light-quark spectroscopy presented at Hadron05 are reviewed. Particular emphasis is given to the status of pentaquarks and of glueballs and exotic mesons. Experiments are proposed to decide on open issues. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

This HADRON05 summary covers the topics of (1) mesons containing heavy quarks, and (2) theory. The new material discussed here is taken mainly from plenary presentations. We specifically emphasize new or recent results in spectroscopy that are likely to appear in future editions of the PDG. An exception is made for the pentaquark, which was withdrawn at this meeting. We undoubtedly have something important to (re)learn about multiquarks from the pentaquark saga, and this merits a phrase in Portuguese. The three general areas we consider are: I. QQ spectroscopy, II. Qq spectroscopy, and III. lessons from the pentaquark. Finally, in Section IIIb. we conclude with “Our moment of Zen”. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Despite the apparent simplicity of meson spectroscopy, light scalar mesons cannot be accommodated in the usual qq structure. We study the description of the scalar mesons below 2 GeV in terms of the mixing of a chiral nonet of tetraquarks with conventional qq states. A strong diquark-antidiquark component is found for several states. The consideration of a glueball as dictated by quenched lattice QCD drives a coherent picture of the isoscalar mesons. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]