Meson-nucleus potentials and the search for meson-nucleus bound states

Science.gov (United States)

Metag, V.; Nanova, M.; Paryev, E. Ya.

2017-11-01

Recent experiments studying the meson-nucleus interaction to extract meson-nucleus potentials are reviewed. The real part of the potentials quantifies whether the interaction is attractive or repulsive while the imaginary part describes the meson absorption in nuclei. The review is focused on mesons which are sufficiently long-lived to potentially form meson-nucleus quasi-bound states. The presentation is confined to meson production off nuclei in photon-, pion-, proton-, and light-ion induced reactions and heavy-ion collisions at energies near the production threshold. Tools to extract the potential parameters are presented. In most cases, the real part of the potential is determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on K+ ,K0 ,K- , η ,η‧ , ω, and ϕ mesons are presented and compared with theoretical predictions. The interaction of K+ and K0 mesons with nuclei is found to be weakly repulsive, while the K- , η ,η‧ , ω and ϕ meson-nucleus potentials are attractive, however, with widely different strengths. Because of meson absorption in the nuclear medium the imaginary parts of the meson-nucleus potentials are all negative, again with a large spread. An outlook on planned experiments in the charm sector is given. In view of the determined potential parameters, the criteria and chances for experimentally observing meson-nucleus quasi-bound states are discussed. The most promising candidates appear to be the η and η‧ mesons.

Meson-meson bound state in a 2+1 lattice QCD model with two flavors and strong coupling

International Nuclear Information System (INIS)

Faria da Veiga, Paulo A.; O'Carroll, Michael; Neto, Antonio Francisco

2005-01-01

We consider the existence of bound states of two mesons in an imaginary-time formulation of lattice QCD. We analyze an SU(3) theory with two flavors in 2+1 dimensions and two-dimensional spin matrices. For a small hopping parameter and a sufficiently large glueball mass, as a preliminary, we show the existence of isoscalar and isovector mesonlike particles that have isolated dispersion curves (upper gap up to near the two-particle threshold ∼-4lnκ). The corresponding meson masses are equal up to and including O(κ 3 ) and are asymptotically of order -2lnκ-κ 2 . Considering the zero total isospin sector, we show that there is a meson-meson bound state solution to the Bethe-Salpeter equation in a ladder approximation, below the two-meson threshold, and with binding energy of order bκ 2 ≅0.02359κ 2 . In the context of the strong coupling expansion in κ, we show that there are two sources of meson-meson attraction. One comes from a quark-antiquark exchange. This is not a meson exchange, as the spin indices are not those of the meson particle, and we refer to this as a quasimeson exchange. The other arises from gauge field correlations of four overlapping bonds, two positively oriented and two of opposite orientation. Although the exchange part gives rise to a space range-one attractive potential, the main mechanism for the formation of the bound state comes from the gauge contribution. In our lattice Bethe-Salpeter equation approach, this mechanism is manifested by an attractive distance-zero energy-dependent potential. We recall that no bound state appeared in the one-flavor case, where the repulsive effect of Pauli exclusion is stronger

Molecular components in P-wave charmed-strange mesons

CERN Document Server

Ortega, Pablo G.

2016-10-26

Results obtained by various experiments show that the $D_{s0}^{\\ast}(2317)$ and $D_{s1}(2460)$ mesons are very narrow states located below the $DK$ and $D^{\\ast}K$ thresholds, respectively. This is markedly in contrast with the expectations of naive quark models and heavy quark symmetry. Motivated by a recent lattice study which addresses the mass shifts of the $c\\bar{s}$ ground states with quantum numbers $J^{P}=0^{+}$ ($D_{s0}^{\\ast}(2317)$) and $J^{P}=1^{+}$ ($D_{s1}(2460)$) due to their coupling with $S$-wave $D^{(\\ast)}K$ thresholds, we perform a similar analysis within a nonrelativistic constituent quark model in which quark-antiquark and meson-meson degrees of freedom are incorporated. The quark model has been applied to a wide range of hadronic observables and thus the model parameters are completely constrained. The coupling between quark-antiquark and meson-meson Fock components is done using a modified version of the $^{3}P_{0}$ decay model. We observe that the coupling of the $0^{+}$ $(1^{+})$ mes...

SACLAY: Eta mesons at Saturne

Energy Technology Data Exchange (ETDEWEB)

Anon.

1992-05-15

Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks.

SACLAY: Eta mesons at Saturne

International Nuclear Information System (INIS)

Anon.

1992-01-01

Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks

Λ(1405) resonance in baryon-meson scattering with a bound state embedded in the continuum

International Nuclear Information System (INIS)

Takeuchi, Sachiko; Shimizu, Kiyotaka

2009-01-01

We investigate Λ(1405) as a resonance in a coupled-channels baryon-meson (Σπ-NK-Λη) scattering with a 'bound state embedded in the continuum' (BSEC). For this purpose, we solve the Lippmann-Schwinger equation including a BSEC with the semirelativistic kinematics in the momentum space. This BSEC is introduced by hand, as a state not originated from a simple baryon-meson system. We assume it comes from the three-quark state. There appears a resonance in the Σπ scattering below the NK threshold without introducing a BSEC when the NK channel has a strong attraction, just like the chiral unitary approach. Even if the baryon-meson interaction is weakened by using a lower-momentum cut-off parameter, a resonance also appears around 1405 MeV when a BSEC is introduced. The corresponding peak also has a large width, and the NK scattering length is well reproduced. The interaction whose channel dependence is the same as the one originated from the color-magnetic interaction, where no NK attraction exists, also gives a broad peak with help of a BSEC. In order to reproduce the observed NK scattering length, the calculation including a BSEC seems to be preferable. Our calculation gives an appropriate NK scattering length when the BSEC contribution to the resonance is roughly half that of the NK channel.

The KK-bar system at low relative energies and the problem of the f0 (975) and a0 (983) mesons

International Nuclear Information System (INIS)

Frascaria, R.

1992-01-01

Meson production near threshold is a spectroscopic tool in the studies of meson structure. Some interesting features of meson production near threshold in few body reactions are emphasized. In particular, the region of KK-bar thresholds studied in pd→ 3 He X at LNS could be an excellent tool to bring new information about the a 0 (983) and f 0 (975) meson structure dilemma. (author) 11 refs., 5 figs

The (0+,1+) heavy meson multiplet in an extended NJL model

International Nuclear Information System (INIS)

Ebert, T.; Feldmann, T.; Friedrich, R.; Reinhardt, H.

1994-09-01

In this letter we reconsider the previously given description of heavy mesons with a bosonized extended NJL model that combines heavy quark and chiral symmetry. In that work the naive gradient expansion of the quark determinant was used, which satisfactorily works in the light sector but does not adequately describe the heavy (0 + , 1 + ) mesons. By investigating the exact momentum dependence of the quark loop we demonstrate that the naive gradient expansion in the heavy sector is not the right method to treat the unphysical q anti q-thresholds which would be absent in confining theories. We propose a modified gradient expansion which adequately extrapolates from the low-momentum region beyond threshold. This expansion gives a satisfactory description even of the (0 + , 1 + ) heavy mesons whose masses are significantly above threshold. (orig.)

Production of charmed mesons in γγ interactions

International Nuclear Information System (INIS)

Braunschweig, W.; Gerhards, R.; Kirschfink, F.J.; Martyn, H.U.; Kolanoski, H.; Hart, J.C.; Saxon, D.H.; Brandt, S.; Holder, M.; Muller, D.; Ritz, S.; Strom, D.; Takashima, M.; Wu Saulan; Zobernig, G.

1990-01-01

Production of charmed mesons in γγ-interactions at PETRA energies has been observed in the TASSO detector. Cross sections for inclusive D *± and D 0 anti D 0 production have been measured. Neutral and charged meson pairs are estimated to be produced with comparable cross sections, and their sum to account for a sizeable function of σ tot (γγ→hadrons) near the canti c threshold. (orig.)

Threshold Research on Highway Length under Typical Landscape Patterns Based on Drivers’ Physiological Performance

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Xia Zhao

2015-01-01

Full Text Available The appropriately landscaped highway scenes may not only help improve road safety and comfort but also help protect ecological environment. Yet there is very little research data on highway length threshold with consideration of distinctive landscape patterns. Against this backdrop, the paper aims to quantitatively analyze highway landscape’s effect on driving behavior based on drivers’ physiological performance and quantify highway length thresholds under three typical landscape patterns, namely, “open,” “semiopen,” and “vertical” ones. The statistical analysis was based on data collected in a driving simulator and electrocardiograph. Specifically, vehicle-related data, ECG data, and supplemental subjective stress perception were collected. The study extracted two characteristic indices, lane deviation and LF/HF, and extrapolated the drivers’ U-shaped physiological response to landscape patterns. Models on highway length were built based on LF/HF’s variation trend with highway length. The results revealed that the theoretical highway length threshold tended to increase when the landscape pattern was switched to open, semiopen, and vertical ones. And the reliability and accuracy of the results were validated by questionnaires and field operational tests. Findings from this research will assist practitioners in taking active environmental countermeasures pertaining to different roadside landscape patterns.

Effects of tubing length and coupling method on hearing threshold and real-ear to coupler difference measures.

Science.gov (United States)

Gustafson, Samantha; Pittman, Andrea; Fanning, Robert

2013-06-01

This tutorial demonstrates the effects of tubing length and coupling type (i.e., foam tip or personal earmold) on hearing threshold and real-ear-to-coupler difference (RECD) measures. Hearing thresholds from 0.25 kHz through 8 kHz are reported at various tubing lengths for 28 normal-hearing adults between the ages of 22 and 31 years. RECD values are reported for 14 of the adults. All measures were made with an insert earphone coupled to a standard foam tip and with an insert earphone coupled to each participant's personal earmold. Threshold and RECD measures obtained with a personal earmold were significantly different from those obtained with a foam tip on repeated measures analyses of variance. One-sample t tests showed these differences to vary systematically with increasing tubing length, with the largest average differences (7-8 dB) occurring at 4 kHz. This systematic examination demonstrates the equal and opposite effects of tubing length on threshold and acoustic measures. Specifically, as tubing length increased, sound pressure level in the ear canal decreased, affecting both hearing thresholds and the real-ear portion of the RECDs. This demonstration shows that when the same coupling method is used to obtain the hearing thresholds and RECD, equal and accurate estimates of real-ear sound pressure level are obtained.

A lattice QCD determination of potentials between pairs of static-light mesons

International Nuclear Information System (INIS)

Hetzenegger, Martin

2011-01-01

Potentials between pairs of static-light mesons are interesting in a sense that they give insights in the nature of strong interactions from first principles for multiquark systems. For large heavy quark masses, e.g., the spectra of heavy-light mesons are determined by excitations of the light quark and gluonic degrees of freedom. In particular, the vector-pseudoscalar splitting vanishes and a static-light meson can be interpreted as either a B, a B * , a D or a D * heavy-light meson. Calculating potentials between two static-light mesons also enables investigations of possible bound tetraquark states or for particles that are close to the meson-antimeson threshold, such as the X(3872) or the Z + (4430).

A lattice QCD determination of potentials between pairs of static-light mesons

Energy Technology Data Exchange (ETDEWEB)

Hetzenegger, Martin

2011-07-04

Potentials between pairs of static-light mesons are interesting in a sense that they give insights in the nature of strong interactions from first principles for multiquark systems. For large heavy quark masses, e.g., the spectra of heavy-light mesons are determined by excitations of the light quark and gluonic degrees of freedom. In particular, the vector-pseudoscalar splitting vanishes and a static-light meson can be interpreted as either a B, a B{sup *}, a D or a D{sup *} heavy-light meson. Calculating potentials between two static-light mesons also enables investigations of possible bound tetraquark states or for particles that are close to the meson-antimeson threshold, such as the X(3872) or the Z{sup +}(4430).

{eta} meson photoproduction on deuterium; Photoproduction du meson {eta} sur le deuterium

Energy Technology Data Exchange (ETDEWEB)

Hoffmann-Rothe, P.

1996-05-30

Measurements of the total and differential cross sections for {eta}-meson photoproduction on a D{sub 2} liquid target from threshold to 1.2 GeV, have been taken using the tagged Bremsstrahlung photon beam produced by the electrons extracted from the ELSA storage ring at Bonn. The reaction was identified by detecting the eta decay products in the neutral meson spectrometer SPES0-2{pi}, while the recoil baryons (proton, neutron or deuteron) were detected by a variety of large angle scintillator detectors. We succeeded to identify completely the final states corresponding to the production of an {eta} meson on a Quasi-Free (QF) proton, a QF neutron and the coherent deuteron. The differential cross sections corresponding to the production of a coherent deuteron n the final state have been measured, from threshold to 800 MeV; they are 6 times smaller the only previous measurement reported by Anderson and Prepost in 1969. This is consistent with an Isoscalar part of the Amplitude much smaller than the Isovector one. The differential cross sections are in good agreement with the theoretical prediction on the impulse approximation mechanism; indicating in particular, fairly small contributions from rescattering terms. A direct measurement of the neutron to proton cross section ratios has been obtained by integrating the counting rates on the corresponding QF peaks and is 0.70 {+-} 0.03, from 700 MeV to 900 MeV, with a small angular dependence. These two results by comparison to the measured free proton data should allow to reconstruct the free neutron cross sections in a rather model-independent way. (authors). 56 refs., 90 figs., 13 tabs.

Low-energy photoproduction of omega-mesons

CERN Document Server

Barth, J; Glander, K H; Hannappel, J; Jöpen, N; Klein, F; Lawall, R; Menze, D; Neuerburg, W; Ostrick, M; Paul, E; Schulday, I; Schwille, W J; Wiegers, B; Ernst, J; Kalinowsky, H; Klempt, E; Link, J; Pee, H V; Klein, F J; Wieland, F W; Wisskirchen, J; Wu, C

2003-01-01

The photoproduction of the vector meson omega has been studied between threshold and W=2.4 GeV with the SAPHIR detector at the Bonn electron stretcher ring ELSA. Besides, the total cross-sections angular distributions in the CMS and decay angular distributions in the helicity and Gottfried-Jackson systems have been measured.

Low-energy photoproduction of PHI-mesons

CERN Document Server

Barth, J; Glander, K H; Hannappel, J; Jöpen, N; Klein, F J; Klein, F; Lawall, R; Menze, D; Neuerburg, W; Ostrick, M; Paul, E; Schulday, I; Schwille, W J; Wiegers, B; Ernst, J; Kalinowsky, H; Klempt, E; Link, J; Pee, H V; Wieland, F W; Wisskirchen, J; Wu, C

2003-01-01

Photoproduction of PHI-vector-mesons has been studied from reaction threshold up to W=2.4 GeV with the SAPHIR spectrometer at the Bonn electron stretcher ring ELSA. Total cross-sections, differential cross-sections and decay angular distributions were measured. We find evidence for strong non-diffractive contributions to PHI photoproduction. (orig.)

Temperature-dependence of Threshold Current Density-Length Product in Metallization Lines: A Revisit

International Nuclear Information System (INIS)

Duryat, Rahmat Saptono; Kim, Choong-Un

2016-01-01

One of the important phenomena in Electromigration (EM) is Blech Effect. The existence of Threshold Current Density-Length Product or EM Threshold has such fundamental and technological consequences in the design, manufacture, and testing of electronics. Temperature-dependence of Blech Product had been thermodynamically established and the real behavior of such interconnect materials have been extensively studied. The present paper reviewed the temperature-dependence of EM threshold in metallization lines of different materials and structure as found in relevant published articles. It is expected that the reader can see a big picture from the compiled data, which might be overlooked when it was examined in pieces. (paper)

submitter Time-dependent CP violation in charm mesons

CERN Document Server

Inguglia, Gianluca

CP violation is a well established phenomenon for B and K mesons, but for D0 mesons, bound states made up of a quark-antiquark pair containing a charm quark, a conclusive answer to the question whether there is CP vio- lation or not, has yet to be determined. I show here the phenomenology of time-dependent CP asymmetries in charm decays, and discuss the implica- tions of experimental tests aimed at the measurement of CP violation in the interference between mixing and decays of charm mesons, in particular when studying the decay channels D0 ! h+h (h = K; ). The decay channels considered can also be used to constrain quantities that are poorly measured or still to be investigated, such as MIX and c;eff , provided that the e ects of penguin pollution are ignored. I considered correlated production of D0 mesons at the SuperB experiment and its planned asymmetric run at the charm threshold and performed a study of simulated events, nding that a boost factor = 0:28 would not be su cient to produce competitive re- ...

Existence of the σ-meson below 1 GeV and chiral symmetry

International Nuclear Information System (INIS)

Krupa, D.; Nagy, M.; Surovtsev, Yu.S.

2000-01-01

In the model-independent approach consisting in the immediate application to the analysis of experimental data of such general principles as analyticity and unitarity, a confirmation of the σ-meson at ∼ 665 MeV and an indication for the glueball nature of the f 0 (1500) state are obtained on the basis of a simultaneous description of the isoscalar s-wave channel of the ππ scattering (from the threshold up to 1.9 GeV) and of the ππ → K anti K scattering are obtained. Existence of the f 0 (665) state and the obtained ππ-scattering length (α 0 0 = 0.27 ± 0.06, m π + -1 ) seems to suggest the linear realization of chiral symmetry

Meson production in the 1 GeV/c2 mass region in the pd → 3He X reaction

International Nuclear Information System (INIS)

Wurzinger, R.; Plouin, F.; Spang, W.; Duval, M.A.; Frascaria, R.; Roudot, F.; Siebert, R.; Warde, E.; Bisplinghoff, J.; Ernst, J.; Hinterberger, F.; Jahn, R.; Joosten, R.; Kozela, A.; Lippert, C.; Von Oepen, T.

1995-01-01

Meson production near threshold has been studied at the SPES4 spectrometer at SATURNE using the pd → 3HeX missing mass reaction. Differential cross sections in the CM system for ω, η ' and φ are less than 1 nb/sr. The observed φ cross section is surprisingly large at threshold and clearly violates the naive OZI rule. No clear signals were obtained at the K anti K thresholds. The measurements can be extended to study broader mesons like f 0 and a 0 . (authors). 8 refs., 2 figs., 1 tab

Scalar mesons and radiative vector meson decays

International Nuclear Information System (INIS)

Gokalp, A.; Ylmaz, O

2002-01-01

The light scalar mesons with vacuum quantum numbers J p =0 ++ have fundamental importance in understanding low energy QCD phenomenology and the symmetry breaking mechanisms in QCD. The nature and quark substructure of the best known scalar mesons, isoscalar σ(500), f0(980) and isovector a0(980) have been a subject of continuous controversy. The radioactive decay of neutral vector mesons ρ, w and φ into a single photon and a pair of neutral pseudoscalar mesons have been studied in order to obtain information on the nature of these scalar mesons. For such studies, it is essential that a reliable understanding of the mechanisms for these decays should be at hand. In this work, we investigate the particularly interesting mechanism of the exchange of scalar mesons for the radiative vector meson decays by analysing the experimental results such as measured decay rates and invariant mass spectra and compare them with the theoretical prediction of different reaction mechanisms

Thermal Properties of Light Tensor Mesons via QCD Sum Rules

Directory of Open Access Journals (Sweden)

K. Azizi

2015-01-01

Full Text Available The thermal properties of f2(1270, a2(1320, and K2*(1430 light tensor mesons are investigated in the framework of QCD sum rules at finite temperature. In particular, the masses and decay constants of the light tensor mesons are calculated taking into account the new operators appearing at finite temperature. The numerical results show that, at the point at which the temperature-dependent continuum threshold vanishes, the decay constants decrease with amount of (70–85% compared to their vacuum values, while the masses diminish about (60–72% depending on the kinds of the mesons under consideration. The results obtained at zero temperature are in good consistency with the experimental data as well as the existing theoretical predictions.

Heavy quark fragmentation functions for D-wave quarkonium and charmed beauty mesons

International Nuclear Information System (INIS)

Cheung, K.; Yuan, T.C.

1995-09-01

At the large transverse momentum region, the production of heavy-heavy bound-states such as charmonium, bottomonium, and anti bc mesons in high energy e + e - and hadronic collisions is dominated by parton fragmentation. The authors calculate the heavy quark fragmentation functions into the D-wave quarkonium and anti bc mesons to leading order in the strong coupling constant and in the non-relativistic expansion. In the anti bc meson case, one set of its D-wave states is expected to lie below the open flavor threshold. The total fragmentation probability for a anti b antiquark to split into the D-wave anti bc mesons is about 2 x 10 -5 , which implies that only 2% of the total pseudo-scalar ground state B c comes from the cascades of these orbitally excited states

Polarisation of the ω meson in the pd→3Heω reaction at 1360 and 1450 MeV

International Nuclear Information System (INIS)

Schoenning, K.; Bargholtz, Chr.; Bashkanov, M.; Berlowski, M.; Bogoslawsky, D.; Calen, H.; Clement, H.; Demiroers, L.; Ekstroem, C.; Fransson, K.; Geren, L.; Gustafsson, L.; Hoeistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.

2008-01-01

The tensor polarisation of ω mesons produced in the pd→ 3 Heω reaction has been studied at two energies near threshold. The 3 He nuclei were detected in coincidence with the π 0 π + π - or π 0 γ decay products of the ω. In contrast to the case of φ-meson production, the ω mesons are found to be unpolarised. This brings into question the applicability of the Okubo-Zweig-Iizuka rule when comparing the production of vector mesons in low energy hadronic reactions

Discovery of omega meson, first neutral vector meson

International Nuclear Information System (INIS)

Anon.

1976-01-01

A personal account of the discovery of the ω meson is given by researcher B. Maglich. His account includes such topics as early and unsuccessful searches for a neutral vector meson (by himself and others), eventual discovery of the rho meson, the Goldhaber effect, and the observation and characterization of the ω meson. Explanatory physics notes on electromagnetic structure experiments and the determination of the quantum numbers of the ω meson are provided for nonspecialists. Also included are an outline of the relation between vector mesons and nuclear forces, a reprint of the Physical Review Letter on Evidence for a T = 0 three-pion resonance, and a scientific autobiography of the researcher. 14 figures, 1 table

Properties of rho and eta mesons in nuclear matter

International Nuclear Information System (INIS)

Herrmann, M.; Sauermann, C.; Friman, B.L.; Technische Hochschule Darmstadt; Noerenberg, W.; Technische Hochschule Darmstadt

1993-10-01

The properties of ρ- and η-mesons in nuclear matter are studied within the scope of hadronic models. Unknown model parameters are obtained from fits to scattering data. - The treatment of the ρ-meson includes the coupling to two pions which, in matter, are strongly mixed with delta-particle-nucleon-hole states. The ρ-meson self-energy is evaluated in a current conserving approximation with in-medium pion propagators and vertex corrections. While the position of the original peak in the spectral function remains almost unchanged, its width grows rapidly with increasing density. Consequently, the ρ-meson strength function is strongly dispersed at high densities. Due to vertex corrections a new peak at a mass around 3m π emerges with increasing density, while the spectral function around the two-pion threshold is found to be smooth at all densities. The η-meson is strongly mixed with N * (1535)-particle-nucleon-hole states in nuclear matter. The corresponding dispersion relations with an upper and a lower branch look similar to those of the (π, ΔN -1 )-modes. However, since the N * is an S-wave resonance in the ηN-channel, the repulsion of the two branches survives at zero momentum. (orig.)

Study of the doubly-charmed decays of B mesons with the experiment BABAR in SLAC; Etude des desintegrations doublement charmees des mesons B avec l'experience BABAR a SLAC

Energy Technology Data Exchange (ETDEWEB)

Robbe, P

2002-04-01

The BABAR experiment at SLAC (Stanford linear acceleration center) has been studying since 1999 B meson decays from e{sup +}e{sup -} collisions at the {gamma}(4S) resonance. The first goal of the collaboration was to measure the sin (2{beta}) CP-violation parameter within the standard model. This measurement requires to know with precision the absolute length scale of the detector. A method to test this scale was developed using nuclear interactions in the beam-pipe material. The longitudinal length scale was then determined at the 1 % level precision. The systematic error associated with length measurement in the detector concerning B meson lifetime and B meson oscillation frequency is then negligible with respect to the other errors. The K meson content of B decays is a key ingredient of the sin (2{beta}) measurement and is used to tag the flavour of the other B in events containing a B decaying to a CP eigenstate. The K charge is correlated to the B flavour. Wrong sign kaons, which can dilute B tagging, can come from wrong sign D decays (B{yields} DX). Doubly charmed decays (B{yields} D{sup (*)}D-bar{sup (*)}) K are one possibility to produce wrong sign D decays. The twenty-two decay modes are reconstructed exclusively. The total branching fraction is measured with enough precision to establish that B{yields} D{sup (*)}D-bar{sup (*)} K decays are not the only source of wrong sign D mesons in B decays. (author)

Study of the neutral meson spectrum near 1000 MeV

Energy Technology Data Exchange (ETDEWEB)

Leeper, R.J.

1975-12-01

The nonstrange neutral meson spectrum from 0.75 to 1.23 GeV/c was studied in the reaction negative pion plus proton goes to neutron plus missing mass at incident beam momenta of 1.98 and 2.41 GeV/c. Neutrons produced by beam interactions in the liquid hydrogen target were detected in the near forward direction in an array of plastic scintillation counters. The missing mass of the remaining particles produced in the final state was determined by a measurement of the neutron time-of-flight. In the case of genuine two-body processes, ..pi../sup -/p ..-->.. n + meson, the observed neutron corresponded to mesons produced forward in the center of mass system. Forward going secondary charge particles produced in the hydrogen target were detected and momentum analyzed by the Argonne Effective Mass Spectrometer. This allowed the isolation of several constrained final states. Arrays of scintillation detectors surrounding the target gave charged particle information and enabled the data to be differentiated into various topological subsamples. The well established ..omega../sup 0/ meson was detected. In addition, a sharp break in the ..pi../sup +/..pi../sup -/n mass spectrum and a rapid rise of the K/sup +/K/sup -/n spectrum just above threshold was observed. Both of these effects were associated with the S* meson. Finally, the absence of four previously observed narrow mesons is discussed.

Proton structure function and Bc meson production in γγ collisions

International Nuclear Information System (INIS)

Martynenko, A.P.; Saleev, V.A.

1996-01-01

Using nonrelativistic quark model and perturbative QCD the production of B c (B* c ) mesons via resolved-photon interaction in γγ-collisions is studied. It is shown that the resolved-photon contribution via partionic subprocess cγ→B c (B* c )b is very important both near threshold of the B c (B* c )-meson production, where the hadron-like part of the photon structure function dominates, and at large energies, where only the point-like part of the photon structure function give the contribution increased versus energy. 18 refs., 5 figs

Meson-meson scattering in lattice QED2+1

International Nuclear Information System (INIS)

Fiebig, H.R.; Woloshyn, R.M.

1993-01-01

Scattering phase shifts of a meson-meson system in staggered 3-dimensional lattice QED are computed. The main task of the simulation is to obtain a discrete set of two-body energy levels. These are extracted from a 4-point time correlation matrix and then used to obtain scattering phase shifts. The results for the l = 0 and l = 2 partial waves are consistent with short-range repulsion and intermediate-range attraction of the residual meson-meson interaction. (orig.)

Recent results on D meson decays from the MARK III

International Nuclear Information System (INIS)

Coward, D.H.

1985-10-01

The MARK III Collaboration recently completed the analysis of a number of decay modes of charged and neutral D mesons produced in electron-positron collisions near the peak of the psi(3770) resonance at SLAC's SPEAR storage ring. The mesons were produced nearly at rest in pairs, either D + D - or D 0 anti D 0 , at a center-of-mass energy below the threshold for DD production. The unique kinematics of the production allow us to isolate the charmed meson signal clearly and unambiguously. The data were collected with the MARK III Spectrometer, a large solid angle magnetic detector. Our data sample corresponds to an integrated luminosity of approximately 9.3 inverse picobarns. New results will be presented on the absolute branching ratios of D mesons into hadronic final states, branching ratios for three body decays via pseudoscalar-vector intermediate states, and branching ratios for Cabibbo allowed and Cabibbo suppressed decays. Inclusive and exclusive branching ratios for the semi-leptonic decays of D mesons will be presented, as well as the first measurement of the vector form factor in the decay D 0 → K - e + nu, evidence for interference in D + decays, and new information on the contributions of W exchange diagrams to D 0 decays

Measurement of the $\\bar{B}^{0}$ and $B^{-}$ Meson Lifetimes

CERN Document Server

Barate, R.; Ghez, Philippe; Goy, C.; Lees, J.P.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Grauges, E.; Martinez, M.; Merino, G.; Miquel, R.; Mir, Ll.M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Boix, G.; Buchmuller, O.; Cattaneo, M.; Cerutti, F.; Dissertori, G.; Drevermann, H.; Forty, R.W.; Frank, M.; Greening, T.C.; Hansen, J.B.; Harvey, John; Janot, P.; Jost, B.; Lehraus, I.; Mato, P.; Minten, A.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Schlatter, D.; Schmitt, M.; Schneider, O.; Spagnolo, P.; Tejessy, W.; Teubert, F.; Tournefier, E.; Wright, A.E.; Ajaltouni, Z.; Badaud, F.; Chazelle, G.; Deschamps, O.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Podlyski, F.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Waananen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Blondel, A.; Bonneaud, G.; Brient, J.C.; Rouge, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Focardi, E.; Parrini, G.; Zachariadou, K.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Halley, A.W.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raine, C.; Teixeira-Dias, P.; Thompson, A.S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Marinelli, N.; Sedgbeer, J.K.; Thompson, J.C.; Thomson, Evelyn J.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C.K.; Buck, P.G.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Robertson, N.A.; Giehl, I.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.G.; Wachsmuth, H.; Zeitnitz, C.; Bonissent, A.; Carr, J.; Coyle, P.; Leroy, O.; Payre, P.; Rousseau, D.; Talby, M.; Aleppo, M.; Ragusa, F.; Dietl, H.; Ganis, G.; Heister, A.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Schael, S.; Settles, R.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Azzurri, P.; Boucrot, J.; Callot, O.; Chen, S.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, Ph.; Jacholkowska, A.; Le Diberder, F.; Lefrancois, J.; Lutz, A.M.; Schune, M.H.; Veillet, J.J.; Videau, I.; Yuan, C.; Zerwas, D.; Bagliesi, Giuseppe; Boccali, T.; Calderini, G.; Ciulli, V.; Foa, L.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciaba, A.; Sguazzoni, G.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Cowan, G.; Green, M.G.; Medcalf, T.; Strong, J.A.; von Wimmersperg-Toeller, J.H.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S.N.; Dann, J.H.; Johnson, R.P.; Kim, H.Y.; Konstantinidis, N.; Litke, A.M.; McNeil, M.A.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Misiejuk, A.; Prange, G.; Sieler, U.; Giannini, G.; Gobbo, B.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.R.; Cranmer, K.; Elmer, P.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P.A., III; Nielsen, J.; Orejudos, W.; Pan, Y.B.; Saadi, Y.; Scott, I.J.; Walsh, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.

2000-01-01

The lifetimes of the B0 and B- mesons are measured using a sample of about four million hadronic Z decays collected from 1991 to 19 95 with the ALEPH detector at LEP. The data sample has been recently reprocessed, achieving a substantial improvement in the tracking performance. Semileptonic decays of B0 and B- mesons are partially reconstructed by identifying events containing a lepton with an associated D* or D0 meson. The proper time of the B meson is estimated from the measured decay length and the momentum of the D-lepton system. A fit to the proper time of 1880 D* l- and 2856 D0 l- candidates yields the following results: tau B0 = 1.518 +- 0.053 +- 0.034 ps, tau B- = 1.648 +- 0.049 +- 0.035 ps, tau B- / tau B0 = 1.085 +- 0.059 +- 0.018.

Meson photoproduction (CLAS)

Energy Technology Data Exchange (ETDEWEB)

Steffen Strauch

2009-10-01

This is a brief and selective discussion of meson photoproduction measurements with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Meson photo- production is being used as a tool for various investigations, including the spectroscopy of baryons and mesons and the search for vector-meson medium modifications.

Study of the doubly-charmed decays of B mesons with the experiment BABAR in SLAC

International Nuclear Information System (INIS)

Robbe, P.

2002-04-01

The BABAR experiment at SLAC (Stanford linear acceleration center) has been studying since 1999 B meson decays from e + e - collisions at the γ(4S) resonance. The first goal of the collaboration was to measure the sin (2β) CP-violation parameter within the standard model. This measurement requires to know with precision the absolute length scale of the detector. A method to test this scale was developed using nuclear interactions in the beam-pipe material. The longitudinal length scale was then determined at the 1 % level precision. The systematic error associated with length measurement in the detector concerning B meson lifetime and B meson oscillation frequency is then negligible with respect to the other errors. The K meson content of B decays is a key ingredient of the sin (2β) measurement and is used to tag the flavour of the other B in events containing a B decaying to a CP eigenstate. The K charge is correlated to the B flavour. Wrong sign kaons, which can dilute B tagging, can come from wrong sign D decays (B→ DX). Doubly charmed decays (B→ D (*) D-bar (*) K are one possibility to produce wrong sign D decays. The twenty-two decay modes are reconstructed exclusively. The total branching fraction is measured with enough precision to establish that B→ D (*) D-bar (*) K decays are not the only source of wrong sign D mesons in B decays. (author)

Measurement of the overlineB0 and B- meson lifetimes

Science.gov (United States)

Buskulic, D.; Decamp, D.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Mours, B.; Pietrzyk, B.; Alemany, R.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Maggi, M.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bauerdick, L. A. T.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Haywood, S.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Lohse, T.; Lusiani, A.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Efthymiopoulos, I.; Kyriakis, A.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Mermikides, M.; Sawyer, L.; Wasserbaech, S.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Belk, A. T.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Dugeay, S.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Nash, J.; Payne, D. G.; Phillips, M. J.; Sedgbeer, J. K.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Aubert, J.-J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Rotscheidt, H.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; Denis, R. St.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bosisio, L.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Focardi, E.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Carter, J. M.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Edwards, M.; Fisher, S. M.; Jones, T. J.; Norton, P. R.; Salmon, D. P.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Perez, P.; Perrier, F.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Carney, R. E.; Cartwright, S.; Combley, F.; Hatfield, F.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Cinabro, D.; Conway, J. S.; Cowen, D. F.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Jared, R. C.; Leclaire, B. W.; Lishka, C.; Pan, Y. B.; Pater, J. R.; Saadi, Y.; Sharma, V.; Schmitt, M.; Shi, Z. H.; Walsh, A. M.; Weber, F. V.; Sau Lan Wu; Wu, X.; Zheng, M.; Zobernig, G.; Aleph Collaboration

1993-06-01

The lifetimes of the overlineB0 and B- mesons have been measured with the ALEPH detector at LEP. Semileptonic decays of overlineB0 and B- mesons were partially reconstructed by identifying events containing a lepton with an associated D ∗+or D 0 meson. The proper time of the B meson was estimated from the measured decay length and the momentum and mass of the D-lepton system. A fit to the proper time of 77 D ∗+ℓ - and 77 D0ℓ - candidates, combined with a constraint on the lifetime ratio ( {τ -}/{τ 0}) arising from the relative rates of observed D ∗+ℓ - and D0ℓ - events, yielded the following lifetimes: τ 0=1.52 -0.18+0.20( stat.) -0.13+0.07( syst.) ps, τ - = 1.47 -0.19+0.22( stat.) -0.14+0.15( syst.) ps, {τ -}/{τ 0} = 0.96 -0.15+0.19( stat.) -0.12+0.18( syst.) .

πK-scattering lengths

International Nuclear Information System (INIS)

Volkov, M.K.; Osipov, A.A.

1983-01-01

The msub(π)asub(0)sup(1/2)=0.1, msub(π)asub(0)sup(3/2)=-0.1, msub(π)asub(0)sup((-))=0.07, msub(π)sup(3)asub(1)sup(1/2)=0.018, msub(π)sup(3)asub(1)aup(3/2)=0.002, msub(π)sup(3)asub(1)sup((-))=0.0044, msub(π)sup(5)asub(2)sup(1/2)=2.4x10sup(-4) and msub(π)sup(5)asub(2)sup(3/2)=-1.2x10sup(-4) scattering lengths are calculated in the framework of the composite meson model which is based on four-quark interaction. The decay form factors of (rho, epsilon, S*) → 2π, (K tilde, K*) → Kπ are used. The q 2 -terms of the quark box diagrams are taken into account. It is shown that the q 2 -terms of the box diagrams give the main contribution to the s-wave scattering lengths. The diagrams with the intermediate vector mesons begin to play the essential role at calculation of the p- and d-wave scattering lengths

Eta meson photoproduction on hydrogen from threshold up to 1100 MeV: Measurement of the {Sigma} beam asymmetry; Photoproduction du meson eta sur l`hydrogene du seuil jusqu`a 1100 MeV: Mesure de l`asymetrie faisceau {Sigma}

Energy Technology Data Exchange (ETDEWEB)

Ajaka, Jassem [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

1997-12-12

The photoproduction of {eta} meson on hydrogen has been measured from threshold to 1100 MeV in GRAAL experiment performed in 1996 - 1997 at the ESRF in Grenoble by a collaboration of Italian, French and Russian groups. A tagged and linearly polarized photon beam has been produced by back-scattering a laser beam on the 6 GeV electron beam of the ESRF ring. The target was a liquid hydrogen target of 3 cm. A 4{pi} detection system was used. It is composed of three layers of detectors: wire chambers, scintillator counters and calorimeters. We had in charge to install and calibrate a double wall of scintillator bars (3 x 3 m) designed to detect at forward angles (1 deg. - 25 deg.) the charged particles and to measure their loss of energy and their time of flight. We analyzed the results of the reaction {gamma}p {yields} {eta}p by identifying the {eta} in the lateral calorimeter which is a BGO ball and by detecting the proton in the scintillation counters. The {Sigma} beam asymmetry was extracted from {phi} distribution of {eta} meson and was plotted against {theta}{sub CM} of {eta} for 6 intervals of energy between the threshold and 1100 MeV. The interpretation of {Sigma} beam asymmetry was performed in the frame of the isobaric model. The use of two resonances S11(1535) and D13(1520) to explain our results was not sufficient. We had to take into account in addition the excitation of the resonances P13(1720), D15(1675) and P13(1880). The last being missing in the table of resonances and recently revealed by quark models. (author) 94 refs., 56 figs., 20 tabs.

Local-duality QCD sum rules for strong isospin breaking in the decay constants of heavy-light mesons

Energy Technology Data Exchange (ETDEWEB)

Lucha, Wolfgang [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); Melikhov, Dmitri [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); M.V. Lomonosov Moscow State University, D.V. Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); University of Vienna, Faculty of Physics, Vienna (Austria); Simula, Silvano [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, Rome (Italy)

2018-02-15

We discuss the leptonic decay constants of heavy-light mesons by means of Borel QCD sum rules in the local-duality (LD) limit of infinitely large Borel mass parameter. In this limit, for an appropriate choice of the invariant structures in the QCD correlation functions, all vacuum-condensate contributions vanish and all nonperturbative effects are contained in only one quantity, the effective threshold. We study properties of the LD effective thresholds in the limits of large heavy-quark mass m{sub Q} and small light-quark mass m{sub q}. In the heavy-quark limit, we clarify the role played by the radiative corrections in the effective threshold for reproducing the pQCD expansion of the decay constants of pseudoscalar and vector mesons. We show that the dependence of the meson decay constants on m{sub q} arises predominantly (at the level of 70-80%) from the calculable m{sub q}-dependence of the perturbative spectral densities. Making use of the lattice QCD results for the decay constants of nonstrange and strange pseudoscalar and vector heavy mesons, we obtain solid predictions for the decay constants of heavy-light mesons as functions of m{sub q} in the range from a few to 100 MeV and evaluate the corresponding strong isospin-breaking effects: f{sub D{sup +}} - f{sub D{sup 0}} = (0.96 ± 0.09) MeV, f{sub D}{sup {sub *}{sub +}} - f{sub D}{sup {sub *}{sub 0}} = (1.18 ± 0.35) MeV, f{sub B{sup 0}} - f{sub B{sup +}} = (1.01 ± 0.10) MeV, f{sub B}{sup {sub *}{sub 0}} - f{sub B}{sup {sub *}{sub +}} = (0.89 ± 0.30) MeV. (orig.)

Omega meson production in proton-proton collisions

International Nuclear Information System (INIS)

Schulte-Wissermann, M.; Brinkmann, K.; Dshemuchadse, S.

2005-01-01

The TOF spectrometer is an external experiment fed by the proton accelerator COSY, which is located at the Forschungszentrum Juelich, Germany. While this detector does not utilize a magnetic field for particle identification, it, however, stands out for its high acceptance (approx. 2π in the laboratory frame) and versatility. TOF measures the velocity-vectors of all charged particles, which then are used to completely reconstruct the event pattern. Due to the modular design of the TOF detector, its components can be assembled to ideally match different experimental requirements. This makes it a multipurpose device, which has shown results for many hadronic channels, starting from the pion threshold up to excess energies as high as 1GeV. One of the experimental programs is dedicated to the ω meson production. In proton-proton interactions, this channel has remained largely unstudied until the late 1990s. Then, first experimental data in the direct vicinity of the threshold and at an excess energy of ε=320 MeV became available. We have published data on ω production for two (intermediate) excess energies of ε=93 MeV and ε=173 MeV. In parallel, a considerable interest on the part of theory arose, since the reaction dynamics of ω-meson production in nucleon-nucleon collisions has an impact on many fields of modern physics. For example, there is an ongoing discussion whether 'missing resonances' may (help to) explain the phenomena observed in dense matter. These resonances would couple to the pω, but not to the pπ channel. Although predicted by many authors, until now no pω resonance was found experimentally; the strangeness content of the nucleon is still an open question. One possible key to an answer is the ratio of the total cross sections of ω to φ - mesons, which experimentally is about a factor of seven larger than simple SU predictions (often referred to as 'violation of the OZI-rule'). However, this comparison is only valid assuming similar

Heavy Scalar, Vector, and Axial-Vector Mesons in Hot and Dense Nuclear Medium

Directory of Open Access Journals (Sweden)

Arvind Kumar

2014-01-01

Full Text Available In this work we shall investigate the mass modifications of scalar mesons (D0; B0, vector mesons (D*; B*, and axial-vector mesons (D1; B1 at finite density and temperature of the nuclear medium. The above mesons are modified in the nuclear medium through the modification of quark and gluon condensates. We will find the medium modification of quark and gluon condensates within chiral SU(3 model through the medium modification of scalar-isoscalar fields σ and ζ at finite density and temperature. These medium modified quark and gluon condensates will further be used through QCD sum rules for the evaluation of in-medium properties of the above mentioned scalar, vector, and axial vector mesons. We will also discuss the effects of density and temperature of the nuclear medium on the scattering lengths of the above scalar, vector, and axial-vector mesons. The study of the medium modifications of the above mesons may be helpful for understanding their production rates in heavy-ion collision experiments. The results of present investigations of medium modifications of scalar, vector, and axial-vector mesons at finite density and temperature can be verified in the compressed baryonic matter (CBM experiment of FAIR facility at GSI, Germany.

Production of polarized vector mesons off nuclei

International Nuclear Information System (INIS)

Kopeliovich, B. Z.; Nemchik, J.; Schmidt, Ivan

2007-01-01

Using the light-cone QCD dipole formalism we investigate manifestations of color transparency (CT) and coherence length (CL) effects in electroproduction of longitudinally (L) and transversally (T) polarized vector mesons. Motivated by forthcoming data from the HERMES experiment we predict both the A and Q 2 dependence of the L/T ratios for ρ 0 mesons produced coherently and incoherently off nuclei. For an incoherent reaction the CT and CL effects add up and result in a monotonic A dependence of the L/T ratio at different values of Q 2 . In contrast, for a coherent process the contraction of the CL with Q 2 causes an effect opposite to that of CT and we expect quite a nontrivial A dependence

Non prompt D-meson measurements with ALICE at the LHC

International Nuclear Information System (INIS)

Mazzilli, Marianna

2016-01-01

The production of hadrons with open heavy flavour (charm and beauty) in high-energy nucleus-nucleus collisions is a powerful tool to study the properties of the deconfined phase of strongly interacting matter known as the Quark-Gluon Plasma (QGP). The production of charm and beauty quarks occurs in hard partonic scattering processes in the early stage of the collisions. ALICE is the LHC experiment devoted to the study of heavy-ion physics. It is able to reconstruct charmed mesons in exclusive decays (e.g. D"0→K"−π"+) and beauty hadrons in semi-inclusive decays (e.g. B→eX, B→J/ψ X) . At LHC energies a significant component of the inclusive D-meson yield originates from the decay of beauty-flavoured hadrons, whose knowledge is essential to determine the production of prompt D mesons coming from charm quarks. A precise determination of the non-prompt fraction combined with the determination of the inclusive D-meson yield would allow a measurement of beauty production. A data-driven method that exploits the different shapes of the distributions of the transverse-plane impact parameter to the primary vertex of prompt and feed-down D mesons in p-Pb collisions is used in ALICE. An alternative approach based on the D-meson decay length for Pb–Pb collisions is under study.

Meson exchange calculation of the p-barp→Lambda-barΛ reaction

International Nuclear Information System (INIS)

Tabakin, F.; Eisenstein, R.A.

1985-01-01

The process p-barp→Lambda-barΛ is studied using a one-boson t-channel strangeness exchange mechanism incorporating pseudoscalar, vector, and tensor mesons. Particular attention is paid to the spin degrees of freedom in the calculation. Initial and final state interactions, including the spin-orbit interaction and absorption, are taken into account using simple phenomenological models. The calculations are performed using density matrix ideas in the helicity basis, and the most important contributing amplitudes are identified. A reasonable fit to existing data can be obtained by allowing a smooth variation of the final state parameters with laboratory momentum. The effect of each of the exchanged mesons, and of the initial- and final-state baryon-baryon interactions on the cross sections and spin observables, is discussed. It is found that the tensor meson exchange plays an essential role even near threshold, which indicates the need for a detailed understanding of the short-range spin dynamics, perhaps as provided by future quark model studies

Spectra and hadronic couplings of light hermaphrodite mesons

International Nuclear Information System (INIS)

Latorre, J.I.; Pascual, P.

1987-01-01

We clarify the discrepancies of previous results for the masses and decay amplitudes of hermaphrodite mesons obtained from QCD sum rules. We study the case of the strange quark within a light quark expansion formalism. We find that the hermaphrodite masses are much higher than the ones of their ordinary meson partners. Our values of the set of masses and continuum thresholds are compared with some other sum rule results. We analyze the hadronic couplings of the isovector 1 -+ exotic hermaprodite ρ tilde using a three-point function sum rule evaluated at the symmetric euclidean point. We find that the ρ tilde can be very broad and prefers to decay into ρπ and K * K. Its most characteristic decays are the ones into πγ, ηπ and η'π. The former and the latter are of the order of (3∝8) MeV. (orig.)

Spectra and hadronic couplings of light hermaphrodite mesons

International Nuclear Information System (INIS)

Latorre, J.I.; Pascual, P.; Narison, S.

1985-12-01

We clarify the discrepancies of previous results for the masses and decay amplitudes of hermaphrodite mesons obtained from QCD sum rules. We study the case of the strange quark within a light quark expansion formalism. We find that the hermaphrodite masses are much higher than the ones of their ordinary meson partners. Our values of the set of masses and continuum thresholds are compared with some other sum rule results. We analyze the hadronic couplings of the isovector 1 -+ exotic hermaphrodite rho-tilde using a three-point function sum rule evaluated at the symmetric euclidean point. We find that the rho-tilde can be very broad and prefers to decay into rhoπ and K*K. Its most characteristic decays are the ones into πγ, etaπ and eta'π. The former and the latter are of the order of (3 to 8) MeV. (author)

Recruitment of single human low-threshold motor units with increasing loads at different muscle lengths.

Science.gov (United States)

McNulty, P A; Cresswell, A G

2004-06-01

We investigated the recruitment behaviour of low threshold motor units in flexor digitorum superficialis by altering two biomechanical constraints: the load against which the muscle worked and the initial muscle length. The load was increased using isotonic (low load), loaded dynamic (intermediate load) and isometric (high load) contractions in two studies. The initial muscle position reflected resting muscle length in series A, and a longer length with digit III fully extended in series B. Intramuscular EMG was recorded from 48 single motor units in 10 experiments on five healthy subjects, 21 units in series A and 27 in series B, while subjects performed ramp up, hold and ramp down contractions. Increasing the load on the muscle decreased the force, displacement and firing rate of single motor units at recruitment at shorter muscle lengths (Precruitment pattern was observed between loaded dynamic and isotonic contractions, but not between isometric and loaded dynamic contractions. Thus, the recruitment properties of single motor units in human flexor digitorum superficialis are sensitive to changes in both imposed external loads and the initial length of the muscle.

Role of nucleon resonance excitation in φ meson photoproduction

International Nuclear Information System (INIS)

Zhao, Q.; Didelez, J.P.; Guidal, M.; Saghai, B.

2000-01-01

The resonance effects are investigated in the φ meson photoproduction near threshold through a quark model approach with an effective Lagrangian. The diffractive contribution is consistently estimated by the t-channel Pomeron exchange. Another non-diffractive process, t-channel π 0 exchange is also included. The numerical result shows that the Pomeron exchange plays dominant role in the φ meson photoproduction, while the cross sections of the non-diffractive processes, i.e., s- and u-channel excitations, and t-channel π 0 exchange, are quite small. In the polarization observables, we find that large asymmetries are produced in the backward direction by the interferences from the s- and u-channel resonances, while in the forward direction, only very small asymmetries are generated. Meanwhile, we find that the effects from the π 0 exchange are generally negligible. (author)

LPI Thresholds in Longer Scale Length Plasmas Driven by the Nike Laser*

Science.gov (United States)

Weaver, J.; Oh, J.; Phillips, L.; Afeyan, B.; Seely, J.; Kehne, D.; Brown, C.; Obenschain, S.; Serlin, V.; Schmitt, A. J.; Feldman, U.; Holland, G.; Lehmberg, R. H.; McLean, E.; Manka, C.

2010-11-01

The Krypton-Fluoride (KrF) laser is an attractive driver for inertial confinement fusion due to its short wavelength (248nm), large bandwidth (1-3 THz), and beam smoothing by induced spatial incoherence. Experiments with the Nike KrF laser have demonstrated intensity thresholds for laser plasma instabilities (LPI) higher than reported for other high power lasers operating at longer wavelengths (>=351 nm). The previous Nike experiments used short pulses (350 ps FWHM) and small spots (<260 μm FWHM) that created short density scale length plasmas (Ln˜50-70 μm) from planar CH targets and demonstrated the onset of two-plasmon decay (2φp) at laser intensities ˜2x10^15 W/cm^2. This talk will present an overview of the current campaign that uses longer pulses (0.5-4.0 ns) to achieve greater density scale lengths (Ln˜100-200 μm). X-rays, emission near ^1/2φo and ^3/2φo harmonics, and reflected laser light have been monitored for onset of 2φp. The longer density scale lengths will allow better comparison to results from other laser facilities. *Work supported by DoE/NNSA and ONR.

Search for a PHI' vector meson in diffractive photoproduction of K+K-π+π-

International Nuclear Information System (INIS)

Atkinson, M.; Davenport, M.; Flower, P.; Hutton, J.S.; Kumar, B.R.; Morris, J.A.G.; Morris, J.V.; Patrick, G.N.; Sharp, P.H.; Bussey, P.J.; Dainton, J.B.; Paterson, C.; Raine, C.; Skillicorn, I.O.; Smith, K.M.; Brodbeck, T.J.; Clegg, A.B.; Flynn, P.J.; Henderson, R.C.W.; Newton, D.; Axon, T.J.; Barberis, D.; Dickinson, B.; Donnachie, A.; Ellison, R.J.; Hughes-Jones, R.E.; Ibbotson, M.; Lafferty, G.D.; Lane, J.B.; Mercer, D.; Thompson, R.J.; Waite, A.P.; Worsell, M.F.; Levy, J.M.; Laberrigue, J.; La Vaissiere, C. de; Yiou, T.P.; Brookes, G.R.; Bunn, J.J.; Galbraith, W.; McClatchey, R.H.

1986-01-01

A study of photoproduction of K + K - π + π - shows a broad threshold enhancement, about 30% of which is due to Ksup(*)Kπ production. This Ksup(*)Kπ component shows no dynamical features indicative of the existence of a PHI' vector meson in this channel. (orig.)

Vector-meson dominance revisited

Directory of Open Access Journals (Sweden)

Terschlüsen Carla

2012-12-01

Full Text Available The interaction of mesons with electromagnetism is often well described by the concept of vector-meson dominance (VMD. However, there are also examples where VMD fails. A simple chiral Lagrangian for pions, rho and omega mesons is presented which can account for the respective agreement and disagreement between VMD and phenomenology in the sector of light mesons.

Color transparency in incoherent electroproduction of ρ mesons off nuclei

International Nuclear Information System (INIS)

Nemchik, J.; Kopeliovich, B. Z.; Potashnikova, I. K.

2013-01-01

Color transparency (CT) phenomena in elastic electroproduction of vector mesons off nuclei are usually infected by the onset of coherence length (CL) effects. However, at low energies corresponding to the CLAS experiment at Jefferson Lab (JLab), one can study practically the net CT effects, since CL is much shorter than the nuclear radius. We investigate various manifestations of CT effects using rigorous quantum mechanical approach based on the path integral technique. We include also the effects of ρ meson decay inside the nucleus leading to a rise of the nuclear suppression towards small values of Q 2 . Motivated by the last CLAS data we predict the A, Q 2 and l c dependence of nuclear transparency for ρ 0 mesons produced incoherently off nuclei. We also perform predictions for expected signal of CT corresponding to the planned JLab upgrade to 12 GeV electron beam.

Color transparency in incoherent electroproduction of {rho} mesons off nuclei

Energy Technology Data Exchange (ETDEWEB)

Nemchik, J. [Institute of Experimental Physics SAS, Watsonova 47, 04001 Kosice, Slovakia and Czech Technical University, FNSPE, Brehova 7, 11519 Praque (Czech Republic); Kopeliovich, B. Z.; Potashnikova, I. K. [Departamento de Fisica y Centro de Estudios Subatomicos, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile)

2013-04-15

Color transparency (CT) phenomena in elastic electroproduction of vector mesons off nuclei are usually infected by the onset of coherence length (CL) effects. However, at low energies corresponding to the CLAS experiment at Jefferson Lab (JLab), one can study practically the net CT effects, since CL is much shorter than the nuclear radius. We investigate various manifestations of CT effects using rigorous quantum mechanical approach based on the path integral technique. We include also the effects of {rho} meson decay inside the nucleus leading to a rise of the nuclear suppression towards small values of Q{sup 2}. Motivated by the last CLAS data we predict the A, Q{sup 2} and l{sub c} dependence of nuclear transparency for {rho}{sup 0} mesons produced incoherently off nuclei. We also perform predictions for expected signal of CT corresponding to the planned JLab upgrade to 12 GeV electron beam.

Photoproduction of Phi-mesons at small momentum transfer

International Nuclear Information System (INIS)

Hirschmann, H.

1975-09-01

The differential cross section of the γp → PHI, p → K + K - p reaction is determined for four-momentum transfer (0 - 0.23) GeV 2 and for photon energies (4.6 - 6.62) GeV with very small error. The differential cross section is independent of energy, the dependence on four-momentum transfer is described by an exponential function with a slope parameter (5.2 +- 0.4) GeV -2 . The total cross section of the PHI-meson as well as its differential cross section for elastic scattering at the proton comes out too small by a factor of 0.6 - 0.7 and 0.5 relative to predictions of a combined vector-dominance-quark model. The trajectories of the forward-going K-mesons are recorded in proportional and spark chambers, a threshold Cherenkov counter discriminates against fast pions and electrons, the principle of track reconstruction out of spark coordinates are explained in detail. (BJ) [de

Physics with ETA mesons

International Nuclear Information System (INIS)

Liu, Lon-chang.

1989-01-01

Since the advent of pion factories, an impressive amount of information about the nuclear dynamics of the Δ(1232) pion- nucleon resonance has been obtained. The study of this isospin-3/2 resonance has greatly benefited from the fact that π/sup /minus//n and π + p systems are pure I = 3/2 states, which couple only to the Δ in the resonance region. Such isospin selectivity of the pion does not exist, however, for the I = 1/2 N* resonances because it is not possible to form a pure I = 1/2 state with a pion and a nucleon. Eta mesons have zero isospin. Consequently, the /eta/N systems are in a pure I = 1/2 state, and /eta/ can be used to tag those N* resonances to which it strongly couples. We will briefly review the πN interaction from the threshold region to c.m. energy √s ≅1600 MeV. We shall see how improved πN data can help the study of πN interactions. I shall discuss what new information about the hadronic interaction can be learned from the study of eta production in pp collisions. The behavior of eta meson in nuclei will be discussed. The interesting question of the quark structure of /eta/(549) and /eta/'(958) will also be discussed within the framework of a simple model. 19 refs., 13 figs

Temperature-dependent cross sections for meson-meson nonresonant reactions in hadronic matter

International Nuclear Information System (INIS)

Zhang Yiping; Xu Xiaoming; Ge Huijun

2010-01-01

We present a potential of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections and of which the large-distance part exhibits a temperature-dependent constant value. The Schroedinger equation with this temperature-dependent potential yields a temperature dependence of the mesonic quark-antiquark relative-motion wave function and of meson masses. The temperature dependence of the potential, the wave function and the meson masses brings about temperature dependence of cross sections for the nonresonant reactions ππ→ρρ for I=2, KK→K*K* for I=1, KK*→K*K* for I=1, πK→ρK* for I=3/2, πK*→ρK* for I=3/2, ρK→ρK* for I=3/2 and πK*→ρK for I=3/2. As the temperature increases, the rise or fall of peak cross sections is determined by the increased radii of initial mesons, the loosened bound states of final mesons, and the total-mass difference of the initial and final mesons. The temperature-dependent cross sections and meson masses are parametrized.

A relativistic, meson exchange model of pion-nucleon scattering

International Nuclear Information System (INIS)

Pearces, B.C.; Jennings, B.K.

1990-06-01

A relativistic meson exchange approach to the pion-nucleon interaction is developed using a three-dimensional relativistic two-body propagator, and the results using different propagators are compared. The relativistic approach is able to describe low energy scattering up to 400 MeV above threshold, while preserving the soft pion theorems. The different propagators give similar results, as the form factors necessary to get a fit suppress much of the multiple scattering. (Author) (24 refs., 4 tabs., 6 figs.)

Study of the photoproduction of the vector meson Φ(1020) and the hyperon Λ(1520) from the production threshold up to a photon energy of 2.65 GeV with SAPHIR

International Nuclear Information System (INIS)

Wiegers, B.

2001-05-01

The photoproduction of the vector meson φ(1020) and the hyperon Λ(1520) have been measured in the finale state pK + K - from their thresholds up to 2.65 GeV using the high duty-factor electron accelerator ELSA and the 4π-detectorsystem SAPHIR. The t-dependence of φ(1020)-production shows an exponential behavior as expected from diffractive production. s-channel helicity conservation can be seen in the decay angular distribution in the helicity frame. The decay angular distribution in the Gottfried-Jackson frame is not conformable with the exchange of a Pomeron in the t-channel. For the first time, differential cross sections of the Λ(1520) photoproduction from the threshold are measured. The production angular distribution and the decay angular distribution in the Gottfried-Jackson frame show a K * exchange in the t-channel. (orig.)

MesonNet Workshop on Meson Transition Form Factors

CERN Document Server

Eidelman, S; Hanhart, C; Kubis, B; Kupsc, A; Leupold, S; Moskal, P; Schadmand, S

2012-01-01

The mini-proceedings of the Workshop on Meson Transition Form Factors held in Cracow from May 29th to 30th, 2012 introduce the meson transition form factor project with special emphasis on the interrelations between the various form factors (on-shell, single off-shell, double off-shell). Short summaries of the talks presented at the workshop follow.

Mesonic and Quark Degrees of Freedom in the Neutron Star Matter

International Nuclear Information System (INIS)

Kubis, S.; Kutschera, M.; Niemiec, J.; Stachniewicz, S.

1999-01-01

Full text: It is expected that mesonic and quark degrees of freedom may play an important role in the physics of dense matter in neutron stars. Any conclusions, however, as to the presence of e.g. meson condensates and/or quark matter inside neutron stars are subject to uncertainties which reflect incompatible model predictions at a purely nucleon level. In our project, as far as mesonic contributions to the equation of state of dense matter are concerned, we focus on the role of kaons and the isovector scalar meson a 0 (980). We find that a threshold density for the kaon condensate to form is very sensitive to a high density behaviour of the electron chemical potential, which is not well known due to uncertainties of nucleon-nucleon interactions. An important effect of the inclusion of the a 0 meson is a splitting of proton and neutron masses in the neutron star matter. A proper construction of the nucleon-quark phase transition in dense neutron star matter predicts that nucleons and quarks coexist over a finite range of pressure, with quarks (nucleons) filling gradually larger (smaller) fraction of space. We find, using a simple bag-model equation of state for the quark matter, that properties of such a mixed quark-nucleon phase are determined by the behaviour of nucleon matter isobars which is sensitive to the nuclear symmetry energy at high densities. We study also implications of the presence of a mixed phase for the structure of neutron stars. (author)

High precision measurement of the {eta} meson mass at COSY-ANKE

Energy Technology Data Exchange (ETDEWEB)

Goslawski, Paul

2013-07-01

Previous measurements of the {eta} meson mass performed at different experimental facilities resulted in very precise data but differ by up to more than eight standard deviations, i.e., 0.5 MeV/c. Interestingly, the difference seems to be dependent on the measuring method: two missing mass experiments, which produce the {eta} meson in the {sup 3}He{eta} final state, deviate from the recent invariant mass ones. In order to clarify this ambiguous situation a high precision mass measurement was realised at the COSY-ANKE facility. Therefore, a set of deuteron laboratory beam momenta and their associated {sup 3}He centre-of-mass momenta was measured in the dp{yields}{sup 3}HeX reaction near the {eta} production threshold. The {eta} meson was identified by the missing mass peak, whereas its mass was extracted by fixing the production threshold. The individual beam momenta were determined with a relative precision of 3 x 10{sup -5} for values just above 3 GeV/c by using a polarised deuteron beam and inducing an artificial depolarising spin resonance occurring at a well-defined frequency. The final state momenta in the two-body reaction dp{yields}{sup 3}He{eta} were investigated in detail by studying the size of the {sup 3}He momentum sphere with the forward detection system of the ANKE spectrometer. Final alignment and momentum calibration of the spectrometer was achieved by a comprehensive study of the {sup 3}He final state momenta as a function of the centre-of-mass angles, taking advantage of the full geometrical acceptance. The value obtained for the mass at COSY-ANKE m{sub {eta}}=(547.873{+-}0.005{sub stat.}{+-}0.027{sub syst.}) MeV/c{sup 2} is therefore worldwide the most precise one. This mass value is contrary to earlier missing mass experiments but it is consistent and competitive with recent invariant mass measurements, in which the meson was detected through its decay products.

Oscillations of neutral K mesons in the theory of dynamical expansion of the weak interaction theory or in the theory of dynamical analogy of the Cabibbo-Kobayashi-Maskawa matrices

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

1998-01-01

The elements of the theory of dynamical expansion of the weak interaction theory working on the tree level, i.e., the theory of dynamical analogy of Cabibbo-Kobayashi-Maskawa matrices, are given. The equation for mass difference of K 1 0 , K 2 0 mesons or the length of K 0 -, K bar 0 - meson oscillations is calculated. In the framework of this theory the oscillations of K 0 , K 0 mesons which arise at violation of strangeness by B bosons are considered. The general conclusion is: the length of K 0 -, K 0 -meson oscillations is proportional to the mass of B boson (which changes strangeness) in the fourth degree

A theory of scalar mesons

International Nuclear Information System (INIS)

Hooft, G. t'; Isidori, G.; Maiani, L.; Polosa, A.D.; Riquer, V.

2008-01-01

We discuss the effect of the instanton induced, six-fermion effective Lagrangian on the decays of the lightest scalar mesons in the diquark-antidiquark picture. This addition allows for a remarkably good description of light scalar meson decays. The same effective Lagrangian produces a mixing of the lightest scalars with the positive parity qq-bar states. Comparing with previous work where the qq-bar mesons are identified with the nonet at 1200-1700 MeV, we find that the mixing required to fit the mass spectrum is in good agreement with the instanton coupling obtained from light scalar decays. A coherent picture of scalar mesons as a mixture of tetraquark states (dominating in the lightest mesons) and heavy qq-bar states (dominating in the heavier mesons) emerges

Charmed meson production at LHCb

International Nuclear Information System (INIS)

Müller, Dominik

2016-01-01

Measurements of charm meson production are important tests for QCD predictions and LHCb is uniquely suited to perform these measurements in the forward region. This paper summarises recent charm meson production measurements performed by LHCb of J/ψ and open charm mesons and the associated production of ϒ and open charm mesons. The J/ψ and open charm meson measurements are performed with data recorded in Run 2 of the Large Hadron Collider. With proton-proton collisions at √s = 13 TeV, these open a new regime in which QCD predictions for charm meson production may be precisely tested. Furthermore, ratios of cross-sections at different centre-of-mass energies benefit of cancellation of both experimental and theoretical uncertainties, providing a new sensitive test of the QCD calculations. Measurements of ϒ and open charm meson associated production are performed using √s = 7 TeV and √s = 8 TeV data and constitute the first observation of this production channel.

Semileptonic Decays of B(B_s) to Light Tensor Mesons

International Nuclear Information System (INIS)

Sadeghi, S.; Khosravi, Reza

2016-01-01

The semileptonic B_s(B)→K_2"⁎(a_2,f_2)lν, l=τ,μ, transitions are investigated in the frame work of the three-point QCD sum rules. Considering the quark condensate contributions, the relevant form factors of these transitions are estimated. The branching ratios of these channel modes are also calculated at different values of the continuum thresholds of the tensor mesons and compared with the obtained data for other approaches.

Perspective of meson science

International Nuclear Information System (INIS)

Yamazaki, T.; Nagamine, K.

1992-01-01

Unstable particles such as mesons and muons are now used in various research domains of physics, chemistry, engineering, and life sciences. This book is aimed at summarizing the present exploratory activities and giving future perspectives from a very broad scope. It contains 27 contributions in a wide range of subjects, such as μSR studies of superconductivities, magnetism, muon beam and μSr methodology, theoretical accounts of muon hyperfine interactions, muon catalyzed fusion processes, metastable exotic atoms, medical diagnostics, strangeness nuclear physics, mesons in nuclei, meson-related nuclear reactions and structure, and exotic decays of mesons

PROPERTIES OF THE $omega$ MESON

Energy Technology Data Exchange (ETDEWEB)

Shafer, J. B.; Murray, J. J.; Ferro-Luzzi, M.; Huwe, D. O.

1963-06-15

Properties of the omega meson were studied from the reaction K/sup -/ + p yields LAMBDA + omega in a 72-in. hydrogen bubble chamber. The momentum of the K/sup -/ mesons was 1.2 to 1.75 Bev/c. The mass of the omega meson is found to be 782 Mev with a width, predominated by three-meson( pi ) decay mode, estimated to be less than 4 Mev. Branching ratios for omega -meson decay into pi /sup +/ pi /sup -/ pi /sup o/, pi /sup o/ gamma , pi /sup +/ i/ sup -/, and e/sup +/e/sup -o/ were determined. (R.E.U.)

Issues in light meson spectroscopy: The case for meson spectroscopy at CEBAF

Energy Technology Data Exchange (ETDEWEB)

Godfrey, S. [Carleton Univ., Ottawa (Canada)

1994-04-01

The author reviews some outstanding issues in meson spectroscopy. The most important qualitative issue is whether hadrons with explicit gluonic degrees of freedom exist. To answer this question requires a much better understanding of conventional q{bar q} mesons. The author therefore begins by examining the status of conventional meson spectroscopy and how the situation can be improved. The expected properties of gluonic excitations are discussed with particular emphasis on hybrids to give guidance to experimental searches. Multiquark systems are commented upon as they are likely to be important in the mass region under study and will have to be understood better. In the final section the author discusses the opportunities that CEBAF can offer for the study of meson spectroscopy.

Chiral Quark-Meson model of N and DELTA with vector mesons

International Nuclear Information System (INIS)

Broniowski, W.; Banerjee, M.K.

1985-10-01

Vector mesons rho, A 1 and ω are introduced in the Chiral Quark-Meson Theory (CQMT) of N and Δ. We propose a new viewpoint for developing CQMT from QCD at the mean-field level. The SU(2) x SU(2) chiral Lagrangian incorporates universal coupling. Accordingly, rho is coupled to the conserved isospin current, A to the partially conserved axial-vector current (PCAC), and ω to the conserved baryon current. As a result the only parameter of the model not directly related to experiment is the quark-pion coupling constant. A fully self-consistent mean-field solution to the model is found for fields in the hedgehog ansatz. The vector mesons play a very important role in the system. They contribute significantly to the values of observables and produce a high-quality fit to many data. The classical stability of the system with respect to hedgehog excitations is analyzed through the use of the Quark-Meson RPA equations (QMRPA)

Recent results from the CELSIUS/WASA collaboration on meson production in proton-hydrogen collisions

International Nuclear Information System (INIS)

Bilger, R.; Bondar, A.; Brodowski, W.; Calen, H.; Clement, H.; Dyring, J.; Ekstroem, C.; Fransson, K.; Gustafsson, L.; Haeggstroem, S.; Hoeistad, B.; Johanson, J.; Johansson, A.; Johansson, T.; Kilian, K.; Kullander, S.; Kupsc, A.; Kuzmin, A.; Marciniewski, P.; Morosov, B.; Moertsell, A.; Oelert, W.; Povtorejko, A.; Ruber, R.J.M.Y.; Schuberth, U.; Sefzick, T.; Sidorov, V.; Shwartz, B.; Sopov, V.; Stepaniak, J.; Sukhanov, A.; Sukhanov, A.; Tchernychev, V.; Turowiecki, A.; Wagner, G.; Wilhelmi, Z.; Zabierowski, J.; Zernov, A.; Zlomanczuk, J.

1999-01-01

Different π and η meson production channels in proton-proton and proton-deuteron collisions have been studied at the CELSIUS storage ring using an internal cluster-jet target setup [1]. During the last years more emphasis has been put on ππ and all but one of the possible channels in proton-proton collisions have been studied. Recently also the quasi-free p+n→d+η reaction cross section has been measured at threshold using 1295 MeV protons and target deuterium. Excess energies from threshold to 10 MeV in the center of mass of the final dη system were covered. Approaching the threshold the cross section is enhanced compared to phase-space expectations. This behaviour is typical for a strong final-state interaction

Exotic hybrid mesons in hard electroproduction

CERN Document Server

Anikin, I V; Szymanowski, L; Teryaev, O V; Wallon, S

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic $J^{PC}=1^{-+}$ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as $1/Q^2$. This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in $\\alpha_{S}$ and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. We study the particular case where the hybrid meson decays through a $\\pi\\eta $ meson pair. We discuss the $\\pi\\eta$ generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of $\\pi$ and $\\eta$ mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very ...

Measurement of the Bc+ meson lifetime using the decay mode Bc+ --> J/Psie+nue.

Science.gov (United States)

Abulencia, A; Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Ben Haim, E; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chapman, J; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, P H; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Cresciolo, F; Cruz, A; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cyr, D; DaRonco, S; D'Auria, S; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Devlin, T; Dionisi, C; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Ebina, K; Efron, J; Ehlers, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garcia Sciveres, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giokaris, N; Giolo, K; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Hahn, K; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hatakeyama, K; Hauser, J; Hays, C; Heijboer, A; Heinemann, B; Heinrich, J; Herndon, M; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Kang, J; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kobayashi, H; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Martin, A; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; von der Mey, M; Miao, T; Miladinovic, N; Miles, J; Miller, R; Miller, J S; Mills, C; Milnik, M; Miquel, R; Mitra, A; Mitselmakher, G; Miyamoto, A; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Naganoma, J; Nahn, S; Nakano, I; Napier, A; Naumov, D; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Ogawa, T; Oh, S H; Oh, Y D; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Paoletti, R; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Rakitin, A; Rappoccio, S; Ratnikov, F; Reisert, B; Rekovic, V; van Remortel, N; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Rott, C; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sanchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Skiba, A; Slaughter, A J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spezziga, M; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tanimoto, N; Tecchio, M; Teng, P K; Terashi, K; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vaiciulis, A; Vallecorsa, S; Varganov, A; Vataga, E; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Wan, Z; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhang, X; Zhou, J; Zucchelli, S

2006-07-07

We present a measurement of the Bc+ meson lifetime in the decay mode Bc+ --> J/Psie+nue using the Collider Detector at Fermilab II detector at the Fermilab Tevatron Collider. From a sample of about of 360 pb(-1) of pp collisions at square root of s = 1.96 TeV, we reconstruct J/Psie+ pairs with invariant mass in the kinematically allowed range 4< M(J/Psie) < 6 GeV/c2. A fit to the decay-length distribution of 238 signal events yields a measured Bc+ meson lifetime of 0.463(-0.065)(+0.073)(stat) +/- 0.036(syst) ps.

Studies of η' (ω) mesons with the crystal ball/TAPS setup at MAMI

Energy Technology Data Exchange (ETDEWEB)

Adlarson, Patrik [Institut fuer Kernphysik, Johannes Gutenberg Universitaet, Mainz (Germany); Collaboration: A2-Collaboration

2015-07-01

Precision studies of light meson decays are used to investigate a wide range of topics related to fundamental aspects of hadron physics. In particular, η' decays allow for tests of such diverse topics as ππ scattering lengths, the SU(3) singlet-octet mixing angle, quark mass differences and light-by-light contribution to the anomalous magnetic moment of the muon. Recently, a large statistics sample of η'(ω) mesons have been produced and collected with the Crystal Ball/TAPS setup at MAMI. An overview of the physics motivation, the experimental setup and preliminary results from the ongoing analyses are presented.

Meson spectroscopy at the Serpukhov accelerator

International Nuclear Information System (INIS)

Prokoshkin, Yu.D.

1987-01-01

At present meson spectroscopy is a dominating direction of experimental studies at the IHEP accelerator. The main attention is paid to the search and study of exotic meson states. This report presents some new results obtained recently at the IHEP accelerator. First, observation is made of a narrow 1750 MeV meson decays into ηη. Above |t| ∼ 0.2 (GeV-c) 2 (t: a square of 4-momentum transferred to a neutron), a clear narrow peak appears in Mηη mass spectrum at a mass of 1750 MeV. Second, 2.22 GeV narrow meson decaying into η'η is described. At present only premature conclusions have been obtained in this area and the situation with ζ is not clear. Third, a study is made on new exotic tensor meson χ(1810) decaying into 4π deg and ηη channels. The decay M deg → 4π deg is a very promissing instrument in search for exotic mesons. Next, G(1590)-meson as a scalar glueball is discussed. BR(G → 4π deg) has a large value, an independent evidence of the exotic nature of G(1590)-meson. Experimental data obtained on all essential decay channels of G(1590)-meson allows to give a selfconsistent description of its production and decay as the scalar glueball, a particle with the dominating gluon component. The final two parts deal with exotic vector meson C(1480) decaying into ψπ deg and observation of D(1285) → ψγ decay. (Nogami, K.)

Spin-zero mesons and current algebras

International Nuclear Information System (INIS)

Wellner, M.

1977-01-01

Large chiral algebras, using the f and d coefficients of SU(3) can be constructed with spin-1/2 baryons. Such algebras have been found useful in some previous investigations. This article examines under what conditions similar or identical current algebras may be realized with spin-0 mesons. A curious lack of analogy emerges between meson and baryon currents. Second-class currents, made of mesons, are required in some algebras. If meson and baryon currents are to satisfy the same extended SU(3) algebra, four meson nonets are needed, in terms of which we give an explicit construction for the currents

Meson-baryon scattering in manifestly Lorentz invariant chiral perturbation theory

International Nuclear Information System (INIS)

Mai, Maxim; Bruns, Peter C.; Kubis, Bastian; Meissner, Ulf-G.

2011-01-01

We analyze meson-baryon scattering lengths in the framework of covariant baryon chiral perturbation theory at leading one-loop order. We compute the complete set of matching relations between the dimension-two low-energy constants in the two- and three-flavor formulations of the theory. We derive new two-flavor low-energy theorems for pion-hyperon scattering that can be tested in lattice simulations.

Electroproduction and photoproduction of vector mesons and generalized vector meson dominance

International Nuclear Information System (INIS)

Fraas, H.; Kuroda, M.

1977-05-01

Using generalized vector meson dominance, electro- and photoproduction of vector mesons is studied. The unnatural parity exchange part of ω(1.2) production is estimated to be about one fourth of that of ω-production. The off diagonal transition model suggests the suppression of diffractive rho(1.2) and ω(1.2) production. (orig.) [de

Deep electroproduction of exotic hybrid mesons

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2004-01-01

We evaluate the leading order amplitude for the deep exclusive electroproduction of an exotic hybrid meson in the Bjorken regime. We show that, contrarily to naive expectation, this amplitude factorizes at the twist 2 level and thus scales like usual meson electroproduction when the virtual photon and the hybrid meson are longitudinally polarized. Exotic hybrid mesons may thus be studied in electroproduction experiments at JLAB, HERA (HERMES) or CERN (Compass)

Exotic hybrid mesons in hard electroproduction

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC =1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e., as 1/Q 2 . This is due to the nonvanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy-momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in α S and we explore the consequences of fixing the renormalization scale ambiguity through the Brodsky-Lepage-Mackenzie (BLM) procedure. We study the particular case where the hybrid meson decays through a πη meson pair. We discuss the πη generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of π and η mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very high energy, in the diffractive limit where a QCD Odderon exchange mechanism should dominate. The conclusion of our study is that hard electroproduction is a promising way to study exotic hybrid mesons, in particular, at JLAB, HERA (HERMES), or CERN (Compass)

Study of the production mechanism of the η meson in proton-proton collisions by means of analysing power measurements

International Nuclear Information System (INIS)

Czyzykiewicz, R.

2007-02-01

The analysing power measurements for the #vector#pp→ppη reaction studied in this dissertation are used in the determination of the reaction mechanism of the η meson production in nucleon-nucleon collisions. Measurements have been performed in the close-to-threshold energy region at beam momenta of p beam =2.010 and 2.085 GeV/c, corresponding to the excess energies of Q=10 and 36 MeV, respectively. The experiments were realised by means of a cooler synchrotron and storage ring COSY along with a cluster jet target. For registration of the reaction products the COSY-11 facility has been used. The identification of the η meson has been performed with the missing mass method. The results for the angular dependence of the analysing power combined with the hitherto determined isospin dependence of the total cross section for the η meson production in the nucleon-nucleon collisions, reveal a statistically significant indication that the excitation of the nucleon to the S 11 resonance, the process which intermediates the production of the η meson, is predominantly due to the exchange of a π meson between the colliding nucleons. The determined values of the analysing power at both excess energies are consistent with zero implying that the η meson is produced predominantly in the s-wave at both excess energies. (orig.)

Nature of the light scalar mesons

International Nuclear Information System (INIS)

Vijande, J.; Valcarce, A.; Fernandez, F.; Silvestre-Brac, B.

2005-01-01

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

Lowest-lying even-parity anti B{sub s} mesons: heavy-quark spin-flavor symmetry, chiral dynamics, and constituent quark-model bare masses

Energy Technology Data Exchange (ETDEWEB)

Albaladejo, M.; Fernandez-Soler, P.; Nieves, J.; Ortega, P.G. [Centro Mixto CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular (IFIC), Institutos de Investigacion de Paterna, Aptd. 22085, Valencia (Spain)

2017-03-15

The discovery of the D{sup *}{sub s0}(2317) and D{sub s1}(2460) resonances in the charmed-strange meson spectra revealed that formerly successful constituent quark models lose predictability in the vicinity of two-meson thresholds. The emergence of non-negligible effects due to meson loops requires an explicit evaluation of the interplay between Q anti q and (Q anti q)(q anti q) Fock components. In contrast to the c anti s sector, there is no experimental evidence of J{sup P} = 0{sup +}, 1{sup +} bottom-strange states yet. Motivated by recent lattice studies, in this work the heavy-quark partners of the D{sub s0}{sup *}(2317) and D{sub s1}(2460) states are analyzed within a heavy meson chiral unitary scheme. As a novelty, the coupling between the constituent quark-model P-wave anti B{sub s} scalar and axial mesons and the anti B{sup (*)}K channels is incorporated employing an effective interaction, consistent with heavy-quark spin symmetry, constrained by the lattice energy levels. (orig.)

Strange mesonic transition form factor

International Nuclear Information System (INIS)

Goity, J.L.; Musolf, M.J.

1996-01-01

The strange-quark vector current ρ-to-π meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a φ-meson dominance model estimate. We find that one-loop contributions are comparable in magnitude to those predicted by φ-meson dominance. It is possible that the one-loop contribution can make the matrix element as large as those of the electromagnetic current mediating vector meson radiative decays. However, due to the quadratic dependence of the one-loop results on the hadronic form factor cutoff mass, a large uncertainty in the estimate of the loops is unavoidable. These results indicate that non-nucleonic strange quarks could contribute appreciable in moderate-parallel Q 2 parallel parity-violating electron-nucleus scattering measurements aimed at probing the strange-quark content of the nucleon. copyright 1996 The American Physical Society

A Measurement of the Charged and Neutral B Meson Lifetimes Using Fully Reconstructed Decays

Energy Technology Data Exchange (ETDEWEB)

Barrera, Barbara

2000-08-30

Data collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC are used to study the lifetimes of the B{sup 0} and B{sup +} mesons. The data sample consists of 7.4 fb{sup -1} collected near the {Upsilon}(4S) resonance. B{sup 0} and B{sup +} mesons are fully reconstructed in several exclusive hadronic decay modes to charm and charmonium final states. The B lifetimes are determined from the flight length difference between the two B mesons which are pair-produced in the {Upsilon}(4S) decay. The preliminary measurements of the lifetimes are {tau}B{sup 0} = 1.506 {+-} 0.052 (stat) {+-} 0.029 (syst) ps, {tau}B{sup +} = 1.602 {+-} 0.049 (stat) {+-} 0.035 (syst) ps, and of their ratio is {tau}B{sup +}/{tau}B{sup 0} = 1.065 {+-} 0.044 (stat) {+-} 0.021 (syst).

A Measurement of the Charged and Neutral B Meson Lifetimes Using Fully Reconstructed Decays

Energy Technology Data Exchange (ETDEWEB)

Barrera, Barbara

2000-08-30

Data collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC are used to study the lifetimes of the B{sup 0} and B{sup +} mesons. The data sample consists of 7.4 fb{sup {minus}1} collected near the Upsilon(4S) resonance. B{sup 0} and B{sup +} mesons are fully reconstructed in several exclusive hadronic decay modes to charm and charmonium final states. The B lifetimes are determined from the flight length difference between the two B mesons which are pair-produced in the Upsilon(4S) decay. The preliminary measurements of the lifetimes are tau{sub B0} = 1.506 {+-} 0.052 (stat) {+-} 0.029 (syst) ps, tau{sub B+} = 1.602 {+-} 0.049 (stat) {+-} 0.035 (syst) ps, and of their ratio is tau{sub B+}/tau{sub B0} = 1.065 {+-} 0.044 (stat) {+-} 0.021 (syst).

Photoproduction of the vector mesons ω(782) and φ(1020) on the proton from the production threshold up to a photon energy of 2. 6 GeV

International Nuclear Information System (INIS)

Barth, J.

2002-05-01

This paper reports on a measurement of the photoproduction of ω(782) and Φ(1020) vector mesons with the SAPHIR detector at the electron accelerator facility ELSA. The incident photons were tagged in an energy range from reaction threshold up to 2.6 GeV. ω and Φ events were selected by separating their signal in the invariant mass spectrum of their decay products, i.e. in the π + π - π 0 and the K + K - system, respectively. As a cross check for normalization the inclusive two and three pion production was evaluated. The results agree with earlier experiments. From the experimental data total cross sections σ tot , differential cross sections dσ/dt as well as decay angular distributions in both, Gottfried Jackson and helicity frames, were extracted. For the ω production they show that diffractive processes play an important role as expected from higher energy data. However, at threshold s-channel resonances significantly contribute. In the region of large four-momentum transfers (vertical stroke t vertical stroke > 1 GeV 2 ) significant deviations from t-channel exchange mechanisms are observed. The Φ production can be described mainly by diffraction, but also other t-channel exchange processes seem to contribute. (orig.)

Meson factories

International Nuclear Information System (INIS)

Dicello, J.F.; Zaider, M.; Bradbury, J.N.

1979-01-01

Technological improvements in accelerator design in the 1960's resulted in the capability to develop medium-energy proton accelerators with beam intensities of almost 1 mA. These beams are able to produce fluxes of secondary particles, including pions, muons, neutrinos, and neutrons, which are as much as 10,000 times as intense as those previously available. Those machines built for optimum meson production are commonly called meson factories. The characteristics of these facilities are reviewed, and the present programs in applied research, and some potential areas of future work are discussed

Nuclear physics at small distances

Indian Academy of Sciences (India)

We report on the study of meson and resonance production in nuclear collisions near the threshold. Because of the large momentum transfer, these reactions occur at length scales less than the size of the hadrons. We explore whether they are best described in terms of the quark–gluon picture or the meson-exchange ...

Workshop on mesons and mesonic states up to slightly above 1 GeV/c2

International Nuclear Information System (INIS)

Oelert, W.; Sefzick, T.

1991-04-01

The new accelerator COSY-Juelich will provide protons with momenta up to 3.3 GeV/c. Thus an effective mass slightly above 1 GeV/c 2 can be produced in the pp-interaction. Employing higher mass targets also heavier mesons can be observed. The production of single mesons and of mesonic states with and without strangeness can be investgated at COSY. The structure of some mesons in the mass range of 950 McV/c 2 to 1020 MeV/c 2 is still not well understood. While the Φ(1020) at the upper limit of this range is believed to be of rahter pure santi s nature the content of the η'(958) meson at the lower limit of this range is still under discussion. New results suggest that what is called the f o meson (former notation S*) consists in reality of two close and narrow states; one of them being a santi s - quarks configuration while the other should be a flavour singlet which couples to ππ and Kanti K with similar strengths. Also the discussion on possible gluonium candidates is still alive. It is speculated that some of these mesons - till now supposed to have widths of 30 to 50 MeV/c 2 - could rather be an overlay of structures with much smaller widths. Another features of resonances in this region is their partial decay into the Kanti K channel if their actual mass is large enough. Strong decays in Kanti K could be a signal of a Kanti K 'molecular' nature of the resonance. In particular the atomic K + K - structure should exist. In order to have review of the physics related to these problems there was a workshop held on: MESONS and MESONIC STATES up to slightly above 1 GeV/c 2 at the ZEL - Forschungszentrum - Juelich February 19 to 20, 1990. The following contains copies of the shown transparencies and short write-ups as far as available. (orig.)

QCD bosonization and the meson effective action

International Nuclear Information System (INIS)

Praschifka, J.; Roberts, C.D.; Cahill, R.T.

1987-01-01

A bosonization of quantum chromodynamics (QCD) is employed to derive a meson effective action, thus providing a direct link between QCD and meson phenomenology. As an example of this approach expressions are obtained for the meson parameters associated with the analysis of ω→3π decay. The bosonization also directly motivates a divergence-free, global color-symmetry model for mesons, which is seen to be a generalization of various phenomenological models. Good estimates are obtained for the values of several of the meson parameters

In-medium QCD sum rules for {omega} meson, nucleon and D meson

Energy Technology Data Exchange (ETDEWEB)

Thomas, Ronny

2008-07-01

The modifications of hadronic properties caused by an ambient nuclear medium are investigated within the scope of QCD sum rules. This is exemplified for the cases of the {omega} meson, the nucleon and the D meson. By virtue of the sum rules, integrated spectral densities of these hadrons are linked to properties of the QCD ground state, quantified in condensates. For the cases of the {omega} meson and the nucleon it is discussed how the sum rules allow a restriction of the parameter range of poorly known four-quark condensates by a comparison of experimental and theoretical knowledge. The catalog of independent four-quark condensates is covered and relations among these condensates are revealed. The behavior of four-quark condensates under the chiral symmetry group and the relation to order parameters of spontaneous chiral symmetry breaking are outlined. In this respect, also the QCD condensates appearing in differences of sum rules of chiral partners are investigated. Finally, the effects of an ambient nuclear medium on the D meson are discussed and relevant condensates are identified. (orig.)

Mesons and quarks in nuclei

International Nuclear Information System (INIS)

Oset, E.

1980-01-01

A short review of the topic of mesons in nuclei is exposed paying particular attention to the relationship between several mesonic processes. Special emphasis is put into the microscopic pictures that can ultimately relate all these processes with the elementary coupling of mesons to the nuclear hadronic components. The importance of the short range part of the nuclear interaction opens the doors to a more basic understanding in terms of the quark components of nucleons and isobars. (orig.)

Towers of hybrid mesons

International Nuclear Information System (INIS)

Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard

2009-01-01

A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.

Charge parity exotic mesons

International Nuclear Information System (INIS)

Burden, C.J.

1998-01-01

Full text: Evidence for a meson with exotic quantum numbers J PC 1 -+ , the ρ(1405), has been observed at the AGS at Brookhaven and Crystal Barrel at CERN. This meson is exotic to the extent that its quantum numbers are not consistent with the generalised Pauli exclusion principle applied to the naive constituent quark model. In a fully relativistic field theoretic treatment, however, there is nothing in principle to preclude the existence of charge parity exotics. Using our earlier covariant Bethe-Salpeter model of light-quark mesons with no new parameter fitting we demonstrate the existence of a q - q-bar bound state with the quantum numbers of the ρ

Spin information from vector-meson decay in photoproduction

International Nuclear Information System (INIS)

Kloet, W.M.; Chiang, W.; Tabakin, F.

1998-01-01

For the photoproduction of vector mesons, all single and double spin observables involving vector-meson two-body decays are defined consistently in the γN center-of-mass frame. These definitions yield a procedure for extracting physically meaningful single and double spin observables that are subject to known rules concerning their angle and energy evolution. As part of this analysis, we show that measuring the two-meson decay of a photo produced ρ or φ does not determine the vector meson's vector polarization, but only its tensor polarization. The vector meson decay into lepton pairs is also insensitive to the vector meson's vector polarization, unless one measures the spin of one of the leptons. Similar results are found for all double spin observables which involve observation of vector-meson decay. To access the vector meson's vector polarization, one therefore needs to either measure the spin of the decay leptons, make an analysis of the background interference effects, or relate the vector meson's vector polarization to other accessible spin observables. copyright 1998 The American Physical Society

Search for rare B meson decays into Ds+ mesons

International Nuclear Information System (INIS)

Albrecht, H.; Ehrlichmann, H.; Hamacher, T.; Hofmann, R.P.; Kirchhoff, T.; Nau, A.; Nowak, S.; Schroeder, H.; Schulz, H.D.; Walter, M.; Wurth, R.; Appuhn, R.D.; Hast, C.; Kolanoski, H.; Lange, A.; Lindner, A.; Mankel, R.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Toepfer, D.; Walther, A.; Wegener, D.; Britton, D.I.; Charlesworth, C.E.K.; Edwards, K.W.; Hyatt, E.R.F.; Kapitza, H.; Krieger, P.; MacFarlane, D.B.; Patel, P.M.; Prentice, J.D.; Saull, P.R.B.; Tzamariudaki, K.; Van de Water, R.G.; Yoon, T.S.; Ressing, D.; Schmidtler, M.; Schneider, M.; Schubert, K.R.; Strahl, K.; Waldi, R.; Weseler, S.; Balagura, V.; Belyaev, I.; Chechelnitsky, S.; Danilov, M.; Droutskoy, A.; Gershtein, Yu.; Golutvin, A.; Gorelov, I.; Kostina, G.; Lubimov, V.; Pakhlov, P.; Ratnikov, F.; Semenov, S.; Shibaev, V.; Soloshenko, V.; Tichomirov, I.; Zaitsev, Yu.

1993-01-01

A search has been performed for rare B meson decays into D s + mesons arising from b→u transitions, W exchange modes, B + annihilation processes, and decays where the D s + is not produced via a W→c anti s quark pair coupling, using the ARGUS detector operating on the Y(4S) resonance at the e + e - storage ring DORIS II. Upper limits for individual decay modes are obtained. In addition, from a study of D s + l - correlations an upper limit of BR(B→D s + l - X)<1.2%(90% CL) is determined. (orig.)

From meson- and photon-nucleon scattering to vector mesons in nuclear matter

International Nuclear Information System (INIS)

Wolf, Gy.; Lutz, M.F.M.; Friman, B.

2003-01-01

A relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, KΛ and KΣ channels is presented. The scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. A fair description of the experimental data relevant to the properties of slow vector mesons in nuclear matter is obtained. The resulting s-wave ρ- and ω-meson-nucleon scattering amplitudes which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter are presented. (author)

Associated strangeness production in pp collisions near threshold

International Nuclear Information System (INIS)

Winter, P.

2004-01-01

Motivated by the ongoing discussion concerning the nature of the scalar resonances f0(980) and a0(980), the COSY-11 collaboration has taken exclusive data on the pp → ppK+K- reaction near the production threshold. A first total cross section σ = (1.80 ± 0.27 -0.35 +0.28 ) nb for the excess energy Q = 17 MeV has been determined. In contrary to the η, ω, and η' single meson production studies which clearly show the strong pp final state interaction (FSI), the cross section values obtained at COSY-11 and DISTO can be both described by a fit with a four-body phase space including the proton-proton final state interaction as well as with one-meson exchange calculations neglecting FSI effects. Therefore, one might think about a compensation of the strong pp interaction through a pK-FSI effect or an additional degree of freedom caused by the four-body final state. In the latter case, strong FSI effects can be expected at Q-values very close to the K+K- production threshold. Such a motivation triggered - in combination with the investigation of the KK-bar interaction being relevant to the structure of the f0 (980) - further measurements at the excess energies Q = 10 and Q 28 MeV at COSY-11

Mesons above the deconfining transition

International Nuclear Information System (INIS)

De Forcrand, P.; Garcia Perez, M.; Hashimoto, T.

1999-01-01

We analyze temporal and spatial meson correlators in quenched lattice QCD at T > 0. Above T c we find different masses and (spatial) 'screening masses', signals of plasma formation, and indication of persisting 'mesonic' excitations. (author)

Scattering amplitudes to all orders in meson exchange

International Nuclear Information System (INIS)

Silbar, R.R.; Mattis, M.P.

1990-01-01

As the number of colors in QCD, N C , becomes large, it is possible to sum up all meson-exchange contributions, however arbitrarily complicated, to meson-baryon and baryon-baryon scattering. A semi-classical structure for the two-flavor theory emerges, in close correspondence to vector-meson-augmented Skyrme models. In this limit, baryons act as extended static sources for the classical meson fields. This leads to non-linear differential equations for the classical meson fields which can be solved numerically for static radial (hedgehog-like) solutions. The non-linear terms in the equations of motion for the quantized meson fields can then be simplified, to leading order in 1/N C , by replacing all factors of the meson field but one by the previously-found classical field. This results in linear, Schroedinger-like equations, which are easily solved. For the meson-baryon case the solution can be subsequently analyzed to obtain the phase shifts for the scattering and, from these, the baryon resonance spectrum of the model. As the warm-up, we have carried out this calculation for the simple case of σ mesons only, finding sensible results. 8 refs., 3 figs

Photoproduction of Mesons off Light Nuclei

International Nuclear Information System (INIS)

Keshelashvili, Irakli

2011-01-01

During the last few years, a series of experiments has been done at the ELSA accelerator in Bonn with the Crystal Barrel/TAPS setup and at the MAMI accelerator in Mainz with the Crystal Ball/TAPS setup. Photoproduction of light mesons off the deuteron and 3 He-nuclei has been studied in detail. We will report some of the most interesting results.A completely unexpected finding, is the pronounced structure in the excitation function of the γn → nη reaction around 1 GeV, which has no counterpart for the proton. Recent measurements at GRAAL, Sendai, ELSA [1] and MAMI estimate it's width below 50 MeV, which would be extremely narrow for a nucleon resonance at this excitation energy. In the experiment with the 3 He target, special attention was given to the threshold behavior of the γHe 3 reactions in view of possible indications for the formation of (quasi-)bound η-nucleus states, so-called η-mesic nuclei. A very strong threshold enhancement of coherent η-photoproduction off 3 He was found. In a new experiment, this reaction was measured with much better statistical accuracy compared to an earlier experiment at MAMI-B using the TAPS detector [2].

Studies on inclusive meson resonance and particle production

International Nuclear Information System (INIS)

Saarikko, Heimo

1978-01-01

Production and decay of meson resonances are studied in medium energy meson-proton collisions. Strong evidence is found that hadronic collisions are dominated by resonance production. Especially the vector mesons have often large inclusive cross sections, typically of the order of few millibarns at the present energies. In all, a majority of pions and kaons appear to be decay products of resonances or other unstable particles. The detailed kinematics of the parent resonance's decays is found to play an important role in determining inclusive pion spectra. The squared transverse momentum distributions of hadrons heavier than the pion appear to have in common an exponential behaviour, with a universal slope for the esponential fall-off. The observed vector meson yields suggest that only a small fraction of the direct lepton production observed at large transverse momentum in nucleon-nucleon interactions is accounted for by the ''old'' vector mesons. An attempt has been made to separate out the central production and fragmentation components of the meson production. Both the central production and the fragmentation of the incoming meson are found to be important mechanisms in the non-strange meson production whereas the central production of strange meson resonances is rare at our energies. The ratios of the observed meson yields are found to be generally in good agreement with a simple quark-counting model. (author)

Tensor meson dominance and e+e--physics

International Nuclear Information System (INIS)

Genz, H.; Karlsruhe Univ.; Mallik, S.

1983-01-01

The phenomenological status of tensor meson dominance is reported. Some new results concerning hadronic decays of the 2 ++ -meson chi 2 (3.55) and the heavy lepton tau are also included. Considering experimental errors, tensor meson dominance is in agreement with experiment. (author)

Single spin asymmetry for charm mesons

Energy Technology Data Exchange (ETDEWEB)

Dominguez Zacarias, G. [PIMAyC, Eje Central Lazaro Cardenas No. 152, Apdo. Postal 14-805, D.F. (Mexico); Herrera, G.; Mercado, J. [Centro de Investigacion y de Estudios Avanzados, Apdo. Postal 14-740, D.F. (Mexico)

2007-08-15

We study single spin asymmetries of D{sup 0} and D{sup -} mesons in polarized proton-proton collisions. A two component model is used to describe charm meson production. The production of D mesons occurs by recombination of the constituents present in the initial state as well as by fragmentation of quarks in the final state. This model has proved to describe the production of charm. The recombination component involves a mechanism of spin alignment that ends up in a single spin asymmetry. Experimental measurements of single spin asymmetry for pions at RHIC are compared with the model. Predictions for the asymmetry in D mesons are presented. (orig.)

Single spin asymmetry for charm mesons

International Nuclear Information System (INIS)

Dominguez Zacarias, G.; Herrera, G.; Mercado, J.

2007-01-01

We study single spin asymmetries of D 0 and D - mesons in polarized proton-proton collisions. A two component model is used to describe charm meson production. The production of D mesons occurs by recombination of the constituents present in the initial state as well as by fragmentation of quarks in the final state. This model has proved to describe the production of charm. The recombination component involves a mechanism of spin alignment that ends up in a single spin asymmetry. Experimental measurements of single spin asymmetry for pions at RHIC are compared with the model. Predictions for the asymmetry in D mesons are presented. (orig.)

Meson Correlators in Finite Temperature Lattice QCD

CERN Document Server

De Forcrand, Philippe; Hashimoto, T; Hioki, S; Matsufuru, H; Miyamura, O; Nakamura, A; Takaishi, T; Umeda, T; Stamatescu, I O; CERN. Geneva; Forcrand, Ph. de

2001-01-01

We analyze temporal and spatial meson correlators in quenched lattice QCD at T>0. Below T_c we observe little change in the meson properties as compared with T=0. Above T_c we observe new features: chiral symmetry restoration and signals of plasma formation, but also indication of persisting mesonic (metastable) states and different temporal and spatial masses in the mesonic channels. This suggests a complex picture of QGP in the region 1 - 1.5 T_c.

Asymptotic energy scale factors for pseudoscalar meson scattering and charmed meson couplings

International Nuclear Information System (INIS)

Thews, R.L.

1977-01-01

Energy scale factors ν 0 for PP → PP scattering amplitudes are related via absence of exotic resonances of ratios of tensor to vector coupling strengths. These same ratios are extracted from FESR's for non-exotic reactions. The scale factors obtained are all of the order of 1.0 GeV 2 or less, indepedent of quantum numbers. This contradicts the expectations of dual amplitudes in which ν 0 =1/α', and trajectory slopes are smaller for charmed mesons. Decay widths for tensor mesons are predicted. An observed SU(3) violation for the ratio A 2 → KantiK/K** → Kπ is shown to be consistent with the FESR results. Charmed meson decays are predicted to be factors of 2 to 3 larger than those predicted by SU(4). (author)

Quantum field theory approaches to meson structure

International Nuclear Information System (INIS)

Branz, Tanja

2011-01-01

Meson spectroscopy became one of the most interesting topics in particle physics in the last ten years. In particular, the discovery of new unexpected states in the charmonium spectrum which cannot be simply explained by the constituent quark model attracted the interest of many theoretical efforts. In the present thesis we discuss different meson structures ranging from light and heavy quark-antiquark states to bound states of hadrons-hadronic molecules. Here we consider the light scalar mesons f 0 (980) and a 0 (980) and the charmonium-like Y(3940), Y(4140) and Z ± (4430) states. In the discussion of the meson properties like mass spectrum, total and partial decay widths and production rates we introduce three different theoretical methods for the treatment and description of hadronic structure. For the study of bound states of mesons we apply a coupled channel approach which allows for the dynamical generation of meson-meson resonances. The decay properties of meson molecules are further on studied within a second model based on effective Lagrangians describing the interaction of the bound state and its constituents. Besides hadronic molecules the effective Lagrangian approach is also used to study the radiative and strong decay properties of ordinary quark-antiquark (q anti q) states. The AdS/QCD model forms the completion of the three theoretical methods introduced in the present thesis. This holographic model provides a completely different ansatz and is based on extra dimensions and string theory. Within this framework we calculate the mass spectrum of light and heavy mesons and their decay constants.

Heavy meson observables and Dyson-Schwinger equations

International Nuclear Information System (INIS)

Ivanov, M. A.

1998-01-01

Dyson-Schwinger equation (DSE) studies show that the b-quark mass-function is approximately constant, and that this is true to a lesser extent for the c-quark. This observation provides the basis for a study of the leptonic and semileptonic decays of heavy pseudoscalar mesons using a ''heavy-quark'' limit of the DSES, which, when exact, reduces the number of independent form factors. Semileptonic decays with light mesons in the final state are also accessible because the DSES provide a description of light-quark propagation characteristics and light-meson structure. A description of B-meson decays is straightforward, however, the study of decays involving the D-meson indicates that c-quark mass-corrections are quantitatively important

Parity violating nuclear force by meson mixing

International Nuclear Information System (INIS)

Iqbal, M.J.; Niskanen, J.A.

1990-01-01

We study a mechanism for parity violation in the two nucleon meson-exchange interaction by way of the mixing of mesons of opposite parities. This mixing arises from parity violating W ± and Z exchange between the q bar q pair in the meson. Numerically its effect turns out to be as important as vector meson exchange with a weak meson-nucleon vertex and may partly be used to model this vertex. The calculation is performed using both the standard Born approximation adding the amplitude phases by Watson's theorem and also using the exact correlated two-nucleon wave functions. The effect of correlations and form factors is found to be crucially important at intermediate energies

Photoproduction of mesons on the nucleon at intermediate energies; Photoproduction de mesons sur le nucleon aux energies intermediaires

Energy Technology Data Exchange (ETDEWEB)

Guidal, M

1997-01-01

In this work a model is proposed to simulate the photoproduction of pseudoscalar mesons ('PI' and K) on the nucleon at high energy. This model is based on the exchange of mesonic or baryonic Regge trajectories, it is gauge invariant and it uses a Feynman diagram formalism inspired from isobaric models. The measurements concerning the following reactions {gamma}p {yields} n{pi}{sup +}, {gamma}n {yields} p{pi}{sup -}, {gamma}p {yields} p{pi}{sup 0} and {gamma}n {yields} n{pi}{sup 0} are reviewed and the new model is confronted to the experimental results. The model gives a reasonable and coherent description of these 4 reactions. The model has also been applied to the photoproduction of strange mesons and of {lambda} and {sigma} baryons and has been extrapolated at low energy to the threshold of the reaction, the model matches the results even up to E{sub {gamma}} = 2 GeV for differential cross-sections and recoil polarization. An attempt has been made to associate a Regge based description, which is valid with low transfers, with perturbative quantum chromodynamics which is valid with high transfers. The model relies on the saturation of trajectories in the high transfer region and on the counting laws that give the right variation of the cross-section. It seems that a model based on linear trajectories can be reliable up to 4 GeV. The domain of high transfer has been too little investigated to provide enough experimental data to validate the model. An experiment whose purpose is to study the photoproduction of {phi} at high transfer, is proposed. This experiment requires an accelerator with high useful cycle because of the smallness of the expected cross-section. The CEBAF (continuous electron beam accelerator facility) as well as the CLAS 4{pi} detector is presented. The study of {gamma}p {yields} p{phi} and {gamma}p {yields} K{lambda}{sup *} (1520) requires the discrimination of kaons from pions so the measurement of 180 ps as time resolution allows the

Exotic meson spectroscopy with CLAS

Energy Technology Data Exchange (ETDEWEB)

Adams, G.; Napolitano, J. [Rensselaer Polytechnic Inst., Troy, NY (United States)

1994-04-01

The identification and study of mesons with explicit gluonic degrees of freedom will provide major constraints on nonperturbative QCD and models thereof. CLAS will provide a unique opportunity for studying these resonances by measuring photoproduction of multi-meson final states.

About oscillations in the system of K0 mesons

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

2011-01-01

This work considers K 0 -, K 0 bar - meson mixings and oscillations via K 1 0 , K 2 0 - meson states at strangeness violation by the weak interactions and K 1 0 -, K 2 0 - meson mixings and oscillations via K S -, K L - meson states at CP violation by the weak interactions without and with taking into account decay widths. We work in the framework of the masses mixing scheme. It is shown that K 1 0 -(K S -) meson states appear at big distances from the K 0 -mesons source after their decays (τ L ≥ τ S (τ 2 ≥τ 1 )) due to oscillations of residual K 2 0 (K L ) mesons and then again we see short-living K 1 0 (K S ) mesons. It is implied that K L ↔K S meson oscillations are absent. The case is also considered when at CP violation unitarity is violated, but orthogonality of K S , K L states remains. The general expressions for probabilities of meson oscillations (transitions) are given

Exclusive φ meson production in HERMES

International Nuclear Information System (INIS)

Golembiovskaya, Mayya

2014-03-01

In the present work exclusive φ meson leptoproduction at HERMES experiment in DESY was studied using the data collected at HERA accelerator in the period from 1998 till 2000 and from 2006 till 2007 years. In the analysis unpolarized and longitudinally polarized hydrogen and deuteron targets were used, the beam consisted of longitudinally polarized leptons. Via measurement of the angular and momentum distribution of the φ meson decay products 23 spin density matrix elements (SDMEs) for the φ meson were obtained. The number of SDMEs was defined by the experiment conditions, e.g. by the beam and target polarization directions. For the mentioned time period φ meson SDMEs were defined at HERMES for the first time. The quantities U 1 , U 2 and U 3 which can be used to check presence of unnatural parity exchange (UPE) mechanism in phi meson production were calculated from SDMEs. All the results were obtained in 3 kinematic bins of Q 2 , 4 kinematic bins of t' and for the integrated kinematics. No statistically significant difference between the results for hydrogen and deuteron targets was observed. The UPE quantities were found to be zero within 2 σ for the integrated kinematics, indicating negligible contribution of UPE for the φ meson production which is in agreement with theory predictions. The test of s-channel helicity conservation hypothesis via comparison of corresponding SDME values showed helicity conservation for the φ meson production.

Exclusive φ meson production in HERMES

Energy Technology Data Exchange (ETDEWEB)

Golembiovskaya, Mayya

2014-03-15

In the present work exclusive φ meson leptoproduction at HERMES experiment in DESY was studied using the data collected at HERA accelerator in the period from 1998 till 2000 and from 2006 till 2007 years. In the analysis unpolarized and longitudinally polarized hydrogen and deuteron targets were used, the beam consisted of longitudinally polarized leptons. Via measurement of the angular and momentum distribution of the φ meson decay products 23 spin density matrix elements (SDMEs) for the φ meson were obtained. The number of SDMEs was defined by the experiment conditions, e.g. by the beam and target polarization directions. For the mentioned time period φ meson SDMEs were defined at HERMES for the first time. The quantities U{sub 1}, U{sub 2} and U{sub 3} which can be used to check presence of unnatural parity exchange (UPE) mechanism in phi meson production were calculated from SDMEs. All the results were obtained in 3 kinematic bins of Q{sup 2}, 4 kinematic bins of t' and for the integrated kinematics. No statistically significant difference between the results for hydrogen and deuteron targets was observed. The UPE quantities were found to be zero within 2 σ for the integrated kinematics, indicating negligible contribution of UPE for the φ meson production which is in agreement with theory predictions. The test of s-channel helicity conservation hypothesis via comparison of corresponding SDME values showed helicity conservation for the φ meson production.

Semileptonic decays of B mesons into excited charm mesons: leading order and 1/mc contributions

International Nuclear Information System (INIS)

Mannel, T.

1994-01-01

We use the heavy quark effective theory to investigate the form factors that describe the semileptonic decays of a B meson into excited daughter mesons. For an excited daughter meson with charm, a single form factor is needed at leading order, while five form factors and two dimensionful constants are needed to order 1/m c in the heavy quark expansion. For non-charmed final states, a total of four form factors are needed at leading order. For the process B→D(*)Xlν, four form factors are also needed at leading order. (orig.)

Discussion of the 3P0 model applied to the decay of mesons into two mesons

International Nuclear Information System (INIS)

Bonnaz, R.; Silvestre-Brac, B.

1999-01-01

The 3 P 0 model for the decay of a meson into two mesons is revisited. In particular, the formalism is extended in order to deal with an arbitrary form for the creation vertex and with the exact meson wave functions. A careful analysis of both effects is performed and discussed. The model is then applied to a large class of transitions known experimentally. Two types of quark-antiquark potentials have been tested and compared. (author)

Production of excited charmed mesons at LEP

CERN Document Server

Abbaneo, D

2000-01-01

Studies od the production of orbitally excited charmed and charmed strange mesons in e+e- collisions, performed by the LEP collaborations are reviewed. Measurements of the production rates of orbitally excited charmed mesons in semileptonic b decays are presented. Searches for charmed meson radial excitations are also briefly discussed.

Hard electroproduction of hybrid mesons

International Nuclear Information System (INIS)

Anikin, I.V.; LPT Universite Paris-Sud, Orsay; Szymanowski, L.; Teryaev, O.V.; ); Wallon, S.

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC = 1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as 1/Q 2 . This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in as and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. (author)

S-wave spectroscopy and Hyperne splitting of Bc meson

International Nuclear Information System (INIS)

Shah, Manan; Bhavsar, Tanvi; Vinodkumar, P.C.

2017-01-01

B c meson is the only heavy meson with two open flavours. This system is also interesting because they cannot annihilate into gluons. The mass spectra and hyperfine splitting of the B c meson are investigated in the Dirac framework with the help of linear + constant potential. The spin-spin interactions are also included in the calculation of the pseudoscalar and vector meson masses. Our computed result for the B c meson are in very good agreement with experimental results as well as other available theoretical result. Decay properties are also interesting because it is expected that decay of B c meson occur in to neutral meson. We hope our theoretical results are helpful for future experimental observations

Search for rare B meson decays into D+s mesons

International Nuclear Information System (INIS)

Albrecht, H.; Ehrlichmann, H.; Hamacher, T.

1993-04-01

A search has been performed for rare B meson decays into D s + mesons arising from b → u transitions, W exchange modes, B + annihilation processes, and decays where the D s + is not produced via a W → c anti s quark pair coupling, using the ARGUS detector operating on the Y(4S) resonance at the e + e - storage ring DORIS II. Upper limits for individual decay modes are obtained. In addition, from a study of D s + l - correlations an upper limit of BR(B → D s + l - X) < 1.2% (90% CL) is determined. (orig.)

Experiments on eta-meson production

International Nuclear Information System (INIS)

Peng, J.C.

1985-01-01

Following a review of some highlights of eta-meson characteristics, the status of eta-meson production experiments is reviewed. The physics motivations and first results of two LAMPF experiments on (π,eta) reactions are discussed. Possible future experiments are also discussed. 42 refs., 12 figs., 4 tabs

The production of {eta} and {omega} mesons in 3.5 GeV p+p interaction in HADES

Energy Technology Data Exchange (ETDEWEB)

Teilab, Khaled

2011-08-31

The study of meson production in proton-proton collisions in the energy range up to one GeV above the production threshold provides valuable information about the nature of the nucleon-nucleon interaction. Theoretical models describe the interaction between nucleons via the exchange of mesons. In such models, different mechanisms contribute to the production of the mesons in nucleon-nucleon collisions. The measurement of total and differential production cross sections provide information which can help in determining the magnitude of the various mechanisms. Moreover, such cross section information serves as an input to the transport calculations which describe e.g. the production of e{sup +}e{sup -} pairs in proton- and pion-induced reactions as well as in heavy ion collisions. In this thesis, the production of {omega} and {eta} mesons in proton-proton collisions at 3.5 GeV beam energy was studied using the High Acceptance DiElectron Spectrometer (HADES) installed at the Schwerionensynchrotron (SIS 18) at the Helmholtzzentrum fuer Schwerionenforschung in Darmstadt. About 80 000 {omega} mesons and 35 000 {eta} mesons were reconstructed. Total production cross sections of both mesons were determined. Furthermore, the collected statistics allowed for extracting angular distributions of both mesons as well as performing Dalitz plot studies. The {omega} and {eta} mesons were reconstructed via their decay into three pions ({pi}{sup +}{pi}{sup -}{pi}{sup 0}) in the exclusive reaction pp {yields} pp{pi}{sup +}{pi}{sup -}{pi}{sup 0}. The charged particles were identified via their characteristic energy loss, via the measurement of their time of flight and momentum, or using kinematics. The neutral pion was reconstructed using the missing mass method. A kinematic fit was applied to improve the resolution and to select events in which a {pi}{sup 0} was produced. The correction of measured yields for the effects of spectrometer acceptance was done as a function of four

Photoproduction of the f1(1285 ) meson

Science.gov (United States)

Dickson, R.; Schumacher, R. A.; Adhikari, K. P.; Akbar, Z.; Amaryan, M. J.; Anefalos Pereira, S.; Badui, R. A.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A.; Boiarinov, S.; Briscoe, W. J.; Burkert, V. D.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Chetry, T.; Ciullo, G.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dugger, M.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fanchini, E.; Fedotov, G.; Filippi, A.; Fleming, J. A.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Holtrop, M.; Hicks, K.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jiang, H.; Jo, H. S.; Joosten, S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Lanza, L.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Mattione, P.; McKinnon, B.; Meyer, C. A.; Mirazita, M.; Markov, N.; Mokeev, V.; Moriya, K.; Munevar, E.; Murdoch, G.; Nadel-Turonski, P.; Net, L. A.; Ni, A.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Phelps, W.; Pisano, S.; Pogorelko, O.; Price, J. W.; Prok, Y.; Puckett, A. J. R.; Raue, B. A.; Ripani, M.; Rizzo, A.; Rosner, G.; Roy, P.; Salgado, C.; Seder, E.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, E. S.; Smith, G. D.; Sober, D.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Strakovsky, I. I.; Stankovic, I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Weygand, D.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zonta, I.; CLAS Collaboration

2016-06-01

The f1(1285 ) meson with mass 1281.0 ±0.8 MeV/c2 and width 18.4 ±1.4 MeV (full width at half maximum) was measured for the first time in photoproduction from a proton target using CLAS at Jefferson Lab. Differential cross sections were obtained via the η π+π-,K+K¯0π- , and K-K0π+ decay channels from threshold up to a center-of-mass energy of 2.8 GeV. The mass, width, and an amplitude analysis of the η π+π- final-state Dalitz distribution are consistent with the axial-vector JP=1+ f1(1285 ) identity, rather than the pseudoscalar 0- η (1295 ) . The production mechanism is more consistent with s -channel decay of a high-mass N* state and not with t -channel meson exchange. Decays to η π π go dominantly via the intermediate a0±(980 ) π∓ states, with the branching ratio Γ [a0π (noK ¯K )] /Γ [η π π (all)] =0.74 ±0.09 . The branching ratios Γ (K K ¯π ) /Γ (η π π ) =0.216 ±0.033 and Γ (γ ρ0) /Γ (η π π ) =0.047 ±0.018 were also obtained. The first is in agreement with previous data for the f1(1285 ) , while the latter is lower than the world average.

Near threshold electroproduction of the ω meson at Q2≅0.5 GeV2

International Nuclear Information System (INIS)

Ambrozewicz, P.; Mitchell, J.; Dunne, J.; Abbott, D.J.; Carlini, R.; Ent, R.; Mack, D.J.; Wood, S.; Yan, C.; Markowitz, P.; Martoff, C.J.; Reinhold, J.; Zeidman, B.; Arrington, J.; Bailey, K.; Cummings, W.J.; Gao, H.; Geesaman, D.F.; Hansen, J.-O.; O'Neill, T.G.

2004-01-01

Electroproduction of the ω meson was investigated in the 1 H(e,e ' p)ω reaction. The measurement was performed at a four-momentum transfer Q 2 ≅0.5 GeV 2 . Angular distributions of the virtual photon-proton center-of-momentum cross sections have been extracted over the full angular range. These distributions exhibit a strong enhancement over t-channel parity exchange processes in the backward direction. According to a newly developed electroproduction model, this enhancement provides significant evidence of resonance formation in the γ*p→ωp reaction channel

Near threshold electroproduction of the omega meson at Q2 ∼ 0.5 GeV2

International Nuclear Information System (INIS)

Ambrozewicz, P.; Mitchell, J.; Dunne, J.; Markowitz, P.; Martoff, C. J.; Reinhold, J.; Zeidman, B.

2004-01-01

Electroproduction of the omega meson was investigated in the p(e,e'p)omega reaction. The measurement was performed at a 4-momentum transfer Q2 ∼ 0.5 GeV2. Angular distributions of the virtual photon-proton center-of-momentum cross sections have been extracted over the full angular range. These distributions exhibit a strong enhancement over t-channel parity exchange processes in the backward direction. According to a newly developed electroproduction model, this enhancement provides significant evidence of resonance formation in the gamma* p -> omega p reaction channel

Antiproton-proton annihilation into light neutral meson pairs within an effective meson theory

Science.gov (United States)

Wang, Ying; Bystritskiy, Yury M.; Ahmadov, Azad I.; Tomasi-Gustafsson, Egle

2017-08-01

Antiproton-proton annihilation into light neutral mesons in the few GeV energy domain is investigated in view of a global description of the existing data and predictions for future work at the Antiproton Annihilation at Darmstadt (PANDA) experiment at the Facility for Antiproton and Ion Research (FAIR). An effective meson model earlier developed, with mesonic and baryonic degrees of freedom in s , t , and u channels, is applied here to π0π0 production. Form factors with logarithmic s and t (u ) dependencies are applied. A fair agreement with the existing angular distributions is obtained. Applying SU(3) symmetry, it is straightforward to recover the angular distributions for π0η and η η production in the same energy range. A good agreement is generally obtained with all existing data.

From meson-baryon scattering to meson photoproduction

Energy Technology Data Exchange (ETDEWEB)

Mai, Maxim

2013-09-01

In the present work we investigate the properties of the lowest baryon resonances. The starting point of our analyses is the low-energy effective theory of quantum chromodynamics, called chiral perturbation theory. As such it describes the long-range observables in terms of the low-energy effects, while the high-energy effects are subsumed in the so-called low-energy constants. In the region of the aforesaid lowest baryon resonances any strict perturbative expansion fails and some resummation scheme is required. For this we employ the Bethe-Salpeter equation (BSE) which guarantees the exact unitarity of the S-matrix and allows to generate resonances dynamically, however, abandoning some other basic principles of quantum field theory as described in chapter 2. Restricting the driving term of this equation to local terms of the second chiral order, we derive an exact solution of the BSE for meson-baryon scattering in chapter 2. Without putting the interaction kernel on shell we preserve the exact correspondence of this solution to an infinite chain of Feynman diagrams. In chapter 4 we apply this ansatz for antikaon-nucleon scattering, trying to get a new insight into the nature of the subthreshold resonance, i.e. {Lambda}(1405). The properties of this resonance have been debated for decades and in recent years it has again attracted a lot of attention by theoreticians since this resonance can be dynamically generated from the so-called chiral unitary approaches. Moreover, the recent measurement of the energy shift and width of kaonic hydrogen in the SIDDHARTA experiment at DA{Phi}NE has provided a very tight constraint on K{sup -}p scattering length. Typically, these approaches predict a two pole structure of {Lambda}(1405), but the question is how precise one can determine the position of these poles relying on data at and above the anti KN threshold. Moreover, we apply our framework for the analysis of pion-nucleon scattering in chapter 3. There we show that the

Meson 2000 Conference Summary lite

International Nuclear Information System (INIS)

Barnes, T.

2000-01-01

This short contribution is a late MESON2000 conference summary. As appropriate for the 600th anniversary of the Jagiellonian University, it begins with a brief summary of the last 600 years of European history and its place in hadron physics. Next a ''physicist chirality'' order parameter PC is introduced. When applied to MESON2000 plenary speakers this order parameter illustrates the separation of hadron physicists into disjoint communities. The individual plenary talks in MESON2000 are next sorted according to the subconference associated with each of the 36 plenary speakers. Finally, I conclude with a previously unreported Feynman story regarding the use of models in hadron physics. (author)

Aspects of meson-baryon scattering in three- and two-flavor chiral perturbation theory

International Nuclear Information System (INIS)

Mai, Maxim; Bruns, Peter C.; Kubis, Bastian; Meissner, Ulf-G.

2009-01-01

We analyze meson-baryon scattering lengths in the framework of covariant baryon chiral perturbation theory at leading one-loop order. We compute the complete set of matching relations between the dimension-two low-energy constants in the two- and three-flavor formulations of the theory. We derive new two-flavor low-energy theorems for pion-hyperon scattering that can be tested in lattice simulations.

Search for modification of vector meson properties in nuclei

International Nuclear Information System (INIS)

Clarisse Tur

2005-01-01

QCD sum rules depict the atomic nucleus as being a medium with partially restored chiral symmetry. This property of the nucleus would imply that the properties of vector mesons, such as their mass and width, are modified when produced in the nuclear medium, since they are controlled by chiral symmetry and its spontaneous as well as explicit breaking in QCD. The g7 (or E01-112) experiment was therefore designed to look for medium effects on the properties of the light vector mesons (rho, omega, and phi) in photoproduction, through their rare leptonic decay into e+e-. This decay channel has been preferred to the two pion channel to avoid distorting the information by strong final interactions. The data for this experiment was taken in the fall of 2002 using the CLAS detector at the Jefferson Laboratory. A bremsstrahlung photon beam was sent on a target containing a liquid deuterium cell and several nuclear targets: C, Fe, Ti, and Pb. Remarkably clean e + e - invariant mass spectra were obtained thanks to the outstanding pion rejection with CLAS and its excellent mass resolution. They represent the first observation of the photoproduction of the rho, omega and phi mesons close to threshold via their rare decay into e+e-. A depletion of the omega and phi peaks was observed with increasing target density. This depletion was not seen as markedly in the simulations done using a code based on the BUU transport equations. The data was broken up per target and fitted using the unmodified rho, omega and phi invariant mass distributions from the BUU simulation code. The Dalitz decay contribution of the omega obtained with the same code as well as the combinatorial background shape from mixed e+e- events were also included in the fit. The overall quality of the fits is suggestive of no medium effects observed on the properties of the vector mesons from this data set. However the contribution from the Bethe-Heitler has to be fully understood and incorporated in the fits before a

The phi-meson and Chiral-mass-meson production in heavy-ion collisions as potential probes of quark-gluon-plasma and Chiral symmetry transitions

Science.gov (United States)

Takahashi, Y.; Eby, P. B.

1985-01-01

Possibilities of observing abundances of phi mesons and narrow hadronic pairs, as results of QGP and Chiral transitions, are considered for nucleus-nucleus interactions. Kinematical requirements in forming close pairs are satisfied in K+K decays of S(975) and delta (980) mesons with small phi, and phi (91020) mesons with large PT, and in pi-pi decays of familiar resonance mesons only in a partially restored chiral symmetry. Gluon-gluon dominance in QGP can enhance phi meson production. High hadronization rates of primordial resonance mesons which form narrow hadronic pairs are not implausible. Past cosmic ray evidences of anomalous phi production and narrow pair abundances are considered.

The η' meson from lattice QCD

International Nuclear Information System (INIS)

Jansen, K.; Michael, C.; Urbach, C.

2008-04-01

We study the flavour singlet pseudoscalar mesons from first principles using lattice QCD. With N f =2 flavours of light quark, this is the so-called η 2 meson and we discuss the phenomenological status of this. Using maximally twisted-mass lattice QCD, we extract the mass of the η 2 meson at two values of the lattice spacing for lighter quarks than previously discussed in the literature. We are able to estimate the mass value in the limit of light quarks with their physical masses. (orig.)

Meson spectroscopy experiment at KEK - E/iota puzzle

International Nuclear Information System (INIS)

Tsuru, Tsuneaki

1985-01-01

Physics interests at the KEK (National Laboratory for High Energy Physics) are (1) search for exotic mesons such as glueballs (gg), meiktons (q anti q g) and multiquark states (q sup(2 - )q 2 ), (2) search for missing ordinary mesons (q anti q) and confirmation of unestablished mesons, and (3) new informations of quark contents of mesons, mixing angles of SU(3) singlet-octet and tests of conservations law. Special interest is in search for exotics such as glueballs and meiktons. (2) is a so-called meson spectroscopy experiment. This is important not only in itself but also in identifying newly discovered states as exotics because exotics have often same quantum numbers as ordinary mesons. Contents are the following: glueballs and E/iota puzzles, spectrometer system, experiments, performance of the spectrometer, physics outputs, E/iota puzzles and πI experiment, future plans. (Mori, K.)

Light meson production and pp-bremsstrahlung at the COSY time-of-flight spectrometer

International Nuclear Information System (INIS)

Kuhlmann, E.; Brand, H.; Brand, S.; Cloth, P.; Dahmen, M.; Drueke, V.; Eyrich, W.; Filges, D.; Freiesleben, H.; Fritsche, A.; Kilian, K.; Kirsch, M.; Koch, H.; Kraft, R.A.; Krug, J.; Lange, S.; Machner, H.; Matthaey, H.; Michel, P.; Mirz, R.; Moeller, K.; Morsch, H.P.; Naumann, B.; Naumann, L.; Oelert, W.; Parsch, A.; Paul, N.; Ringe, P.; Roderburg, E.; Roehrich, K.; Roeser, A.; Rogge, M.; Schmidt, G.; Schmidt, M.; Schult, O.; Sefzick, T.; Steinke, M.; Stinzing, F.; Stratmann, R.; Turek, P.; Werding, R.; Wirth, S.

1993-01-01

Experiments on light meson production and pp-bremsstrahlung as planned for the initial stage at COSY are discussed. Special emphasis will be placed on near-threshold behaviour where due to kinematics all particles are forced into a rather narrow cone around the beam axis. A specially designed charged particle detector system will be used which not only covers the complete forward hemisphere of 2π in the laboratory system but additionally shows maximum resolution in the extreme forward direction with only moderate cuts in the minimally required energy of all ejectiles. (orig.)

Temperature, chemical potential and the ρ meson

International Nuclear Information System (INIS)

Roberts, C. D.; Schmidt, S. M.

2000-01-01

Models of QCD must confront nonperturbative phenomena such as confinement, dynamical chiral symmetry breaking (DCSB) and the formation of bound states. In addition, a unified approach should describe the deconfinement and chiral symmetry restoring phase transition exhibited by strongly-interacting matter under extreme conditions of temperature and density. Nonperturbative Dyson-Schwinger equation (DSE) models provide insight into a wide range of zero temperature hadronic phenomena; e.g., non-hadronic electroweak interactions of light- and heavy-mesons, and diverse meson-meson and meson-nucleon form factors. This is the foundation for their application at nonzero-(T, μ). Herein the authors describe the calculation of the reconfinement and chiral symmetry restoring phase boundary, and the medium dependence of ρ-meson properties. They also introduce an extension to describe the time-evolution in the plasma of the quark's scalar and vector self energies based on a Vlasov equation

Spin O decay angular distribution for interfering mesons in electroproduction

Energy Technology Data Exchange (ETDEWEB)

Funsten, H.; Gilfoyle, G.

1994-04-01

Self analyzing meson electroproduction experiments are currently being planned for the CEBAF CLAS detector. These experiments deduce the spin polarization of outgoing unstable spin s (?)0 mesons from their decay angular distribution, W({theta},{psi}). The large angular acceptance of the CLAS detector permits kinematic tracking of a sufficient number of these events to accurately determine electroproduction amplitudes from the deduced polarization. Maximum polarization information is obtained from W({theta},{psi}) for decay into spin 0 daughters. The helicity of the decaying meson is transferred to the daughter`s relative orbital angular momentum m-projection; none is {open_quotes}absorbed{close_quotes} into daughter helicities. The decaying meson`s helicity maximally appears in W({theta},{psi}). W({theta},{psi}) for spin 0 daughters has been derived for (1) vector meson electroproduction and (2) general interfering mesons produced by incident pions. This paper derives W({theta},{psi}) for electroproduction of two interfering mesons that decay into spin 0 daughters. An application is made to the case of interfering scalar and vector mesons. The derivation is an extension of work by Schil using the general decay formalism of Martin. The expressions can be easily extended to the case of N interfering mesons since interference occurs pairwise in the observable W ({theta},{psi}), a quadratic function of the meson amplitudes. The derivation uses the virtual photon density matrix of Schil which is transformed by a meson electroproduction transition operator, T. The resulting density matrix for the interfering mesons is then converted into a corresponding statistical tensor and contracted into the efficiency tensor for spin 0 daughters.

The light scalar mesons as tetraquarks

Directory of Open Access Journals (Sweden)

Gernot Eichmann

2016-02-01

Full Text Available We present a numerical solution of the four-quark Bethe–Salpeter equation for ground-state scalar tetraquarks with JPC=0++. We find that the four-body equation dynamically generates pseudoscalar-meson poles in the Bethe–Salpeter amplitude. The resulting tetraquarks are genuine four-quark states that are dominated by pseudoscalar meson–meson correlations. Diquark–antidiquark contributions are subleading because of their larger mass scale. In the light quark sector, the sensitivity of the tetraquark wave function to the pion poles leads to an isoscalar tetraquark mass Mσ∼350 MeV which is comparable to that of the σ/f0(500. The masses of its multiplet partners κ and a0/f0 follow a similar pattern. This provides support for a tetraquark interpretation of the light scalar meson nonet in terms of ‘meson molecules’.

Lifetime measurements of charmed mesons with high resolution silicon detectors

International Nuclear Information System (INIS)

Rijk, G.A.F. de.

1986-01-01

In this thesis an experiment is described to measure the lifetimes of pseudoscalar charmed mesons. The experiment uses a negatively charged unseparated hadron beam of 200 GeV. The experiment is carried out with a magnetic spectrometer preceded by a beam telescope, an active target and a vertex telescope, all consisting of Si microstrip detectors. The spectrometer consists of two spectrometer magnets, 48 planes of drift chambers and 3 Cerenkov hodoscopes for the determination and identification of charged secondaries. The lifetimes of the charmed mesons are determined by measuring the length of their flight path, their momentum and their mass. The results, which are described in the thesis, are based on the analysis of part of the collected data. The production rates in the K - beam and in the π - beam are found to be in the same order of magnitude within the x F range covered. Previous experimental data on the lifetimes of charmed particles are reviewed. A theoretical interpretation is presented of the measured decay properties. (Auth.)

Light Vector Mesons in the Nuclear Medium

Energy Technology Data Exchange (ETDEWEB)

Wood, Michael; Nasseripour, Rakhsha; Weygand, Dennis; Djalali, Chaden; Tur, Clarisse; Mosel, Ulrich; Muehlich, Pascal; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, James; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Carnahan, Bryan; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crannell, Hall; Crede, Volker; Cummings, John; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dharmawardane, Kahanawita; Dickson, Richard; Dodge, Gail; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gordon, Christopher; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hakobyan, Rafael; Hanretty, Charles; Hardie, John; Hassall, Neil; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Li, Ji; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Ronchetti, Federico; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Stepan; Stepanyan, Samuel; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Watts, Daniel; Weinstein, Lawrence; Williams, Michael; Wolin, Elliott; Yegneswaran, Amrit; Zana, Lorenzo; Zhang, Bin; Zhang, Jixie; Zhao, Bo; Zhao, Zhiwen

2008-07-01

The light vector mesons ($\\rho$, $\\omega$, and $\\phi$) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the $\\rho$ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to $e^{+}e^{-}$. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The $\\rho$ meson mass spectrum was extracted after the $\\omega$ and $\\phi$ signals were removed in a nearly model-independent way. Comparisons were made between the $\\rho$ mass spectra from the heavy targets ($A > 2$) with the mass spectrum extracted from the deuterium target. With respect to the $\\rho$-meson mass, we obtain a small shift compatible with zero. Also, we measure widths consistent with standard nuclear many-body eff

Meson spectroscopy, quark mixing and quantum chromodynamics

International Nuclear Information System (INIS)

Filippov, A.T.

1979-01-01

A semiphenomenological theory of mass spectrum for mesons, consisting of a quark-antiquark pair, is presented. Relativistic kinematical effects of the quark mass differences, the SU(3)-symmetry breaking in slopes of the Regge trajectories and in radially excited states are taken into account. The OZI-rule breaking is taken into account by means of the mixing matrix for the quark wave functions, whose form is suggested by the quantum chromodynamics. A simple extrapolation of expression, given by the quantum chromodynamics from the ''asymptotic freedom'' region to the ''infrared slavery'' region is proposed to describe the dependence of the mixing parameters on the meson masses. To calculate masses and mixing angles for pseudoscalar mesons a condition is proposed that the pion mass is minimal. In this situation the eta-meson mass is near the maximal value. The predictions of the theory for masses and mixing angles of the mesons are in good agreement with the experiment

Rapidity resummation for B-meson wave functions

Directory of Open Access Journals (Sweden)

Shen Yue-Long

2014-01-01

Full Text Available Transverse-momentum dependent (TMD hadronic wave functions develop light-cone divergences under QCD corrections, which are commonly regularized by the rapidity ζ of gauge vector defining the non-light-like Wilson lines. The yielding rapidity logarithms from infrared enhancement need to be resummed for both hadronic wave functions and short-distance functions, to achieve scheme-independent calculations of physical quantities. We briefly review the recent progress on the rapidity resummation for B-meson wave functions which are the key ingredients of TMD factorization formulae for radiative-leptonic, semi-leptonic and non-leptonic B-meson decays. The crucial observation is that rapidity resummation induces a strong suppression of B-meson wave functions at small light-quark momentum, strengthening the applicability of TMD factorization in exclusive B-meson decays. The phenomenological consequence of rapidity-resummation improved B-meson wave functions is further discussed in the context of B → π transition form factors at large hadronic recoil.

Charged track multiplicity in B meson decay

International Nuclear Information System (INIS)

Brandenburg, G.; Ershov, A.; Gao, Y. S.; Kim, D. Y.-J.; Wilson, R.; Browder, T. E.; Li, Y.; Rodriguez, J. L.; Yamamoto, H.; Bergfeld, T.

2000-01-01

We have used the CLEO II detector to study the multiplicity of charged particles in the decays of B mesons produced at the Υ(4S) resonance. Using a sample of 1.5x10 6 B meson pairs, we find the mean inclusive charged particle multiplicity to be 10.71±0.02 -0.15 +0.21 for the decay of the pair. This corresponds to a mean multiplicity of 5.36±0.01 -0.08 +0.11 for a single B meson. Using the same data sample, we have also extracted the mean multiplicities in semileptonic and nonleptonic decays. We measure a mean of 7.82±0.05 -0.19 +0.21 charged particles per BB(bar sign) decay when both mesons decay semileptonically. When neither B meson decays semileptonically, we measure a mean charged particle multiplicity of 11.62±0.04 -0.18 +0.24 per BB(bar sign) pair. (c) 2000 The American Physical Society

Measurement of the reaction 12C(νμ,μ-)X near threshold

International Nuclear Information System (INIS)

Albert, M.; Athanassopoulos, C.; Auerbach, L.B.; Bauer, D.; Bolton, R.; Boyd, B.; Burman, R.L.; Cohen, I.; Caldwell, D.O.; Dieterle, B.D.; Donahue, J.B.; Eisner, A.M.; Fazely, A.; Federspiel, F.J.; Garvey, G.T.; Gunasingha, R.M.; Highland, V.; Hill, J.; Imlay, R.; Johnston, K.; Louis, W.C.; Lu, A.; Mann, A.K.

1995-01-01

The reaction 12 C(ν μ ,μ - )X has been measured near threshold using a π + decay-in-flight ν μ beam from the Los Alamos Meson Physics Facility and a massive liquid scintillator neutrino detector (LSND). In the energy region 123.7 ν -40 cm 2 } is more than a factor of 2 lower than that predicted by the Fermi-gas model and by a recent random phase approximation calculation

Further evidence for magnetic charge from meson spectroscopy

International Nuclear Information System (INIS)

Akers, D.

1987-01-01

Recently evidence was presented for the existence of magnetic charge from Zeeman splitting in meson states. The model by Akers predicted the existence of a new eta meson at 1814 MeV with I/sup G/ (J/sup PC/) = O + (O -+ ). Experimental evidence for this new meson is cited and discussed

The Meson Spectroscopy Program at the Jefferson Laboratory

Energy Technology Data Exchange (ETDEWEB)

Filippi, Alessandro [Istituto Nazionale di Fisica Nucleare (INFN), Torino (Italy). et al.

2015-06-01

The experimental techniques that will be applied by the next generation meson spectroscopy experiments at JLab are described. For the first time, these experiments will be able to exploit the features of a photon beam of unprecedented intensity and momentum resolution, that will allow to perform precision studies of meson states with masses below 3 GeV/c². Photon induced reactions will enhance the production of spin-1 mesons, that are of particular interest according to the most recent Lattice QCD calculations of the lightest exotic hybrid meson.

Meson facility. Powerful new research tool

International Nuclear Information System (INIS)

Lobashev, V.M.; Tavkhelidze, A.N.

A meson facility is being built at the Institute of Nuclear Research, USSR Academy of Sciences, in Troitsk, where the Scientific Center, USSR Academy of Sciences is located. The facility will include a linear accelerator for protons and negative hydrogen ions with 600 MeV energy and 0.5-1 mA beam current. Some fundamental studies that can be studied at a meson facility are described in the areas of elementary particles, neutron physics, solid state physics, and applied research. The characteristics of the linear accelerator are given and the meson facility's experimental complex is described

Search for radiative B meson decays

International Nuclear Information System (INIS)

Lesiak, T.; Muryn, B.; Nowak, G.; Antreasyan, D.; Irion, J.; McBride, P.; Strauch, K.; Bartels, H.W.; Bienlein, J.K.; Brockmueller, K.; Jakubowski, Z.; Karch, K.; Kloiber, T.; Koch, W.; Maschmann, W.; Meyer, H.; Skwarnicki, T.; Trost, H.J.; Voigt, A.; Wachs, K.; Zschorsch, P.; Besset, D.; Cabenda, R.; Cowan, R.; Bieler, C.; Graaf, K.; Heinsius, F.H.; Kiel, T.; Krueger, S.; Lekebusch, R.; Nernst, R.; Sievers, D.; Stock, V.; Strohbusch, U.; Bloom, E.D.; Clare, R.; Cooper, S.; Fairfield, K.; Fridman, A.; Gaiser, J.; Gelphman, D.; Godfrey, G.; Hofstadter, R.; Kirkbride, I.; Lee, R.; Leffler, S.; Litke, A.M.; Lockman, W.; Lowe, S.; Niczyporuk, B.; Pollock, B.; Schwarz, A.; Tompkins, J.; Van Uitert, B.; Wacker, K.; Brock, I.; Engler, A.; Kraemer, R.W.; Marlow, D.; Messing, F.; Prindle, D.; Renger, B.; Rippich, C.; Vogel, H.; Cavalli-Sforza, M.; Coyne, D.; Folger, G.; Glaser, G.; Kobel, M.; Lurz, B.; Schuette, J.; Volland, U.; Wegener, H.; Janssen, H.; Koenig, A.C.; Metzger, W.J.; Reidenbach, M.; Schotanus, J.; Walle, R.T. van de; Walk, W.; Keh, S.; Kilian, H.; Koenigsmann, K.; Scheer, M.; Schmitt, P.; Marsiske, H.; Williams, D.A.

1992-01-01

The Crystal Ball detector at the e + e - storage ring DORIS-II has been used to search for radiative B meson decays, especially of the type b→sγ. No mono-energetic γ-lines have been found in the inclusive photon spectrum from Υ(4S) decays, and upper limits are obtained for radiative decays of B mesons to various strange mesons and to the D*. Integrating the photon spectrum over the corresponding energy range, we find BR(B→γX) -3 , at 90% confidence level for the mass range 892 MeV≤M X ≤2045 MeV. (orig.)

Search for radiative B meson decays

International Nuclear Information System (INIS)

Lesiak, T.; Muryn, B.; Nowak, G.; Antreasyan, D.; Irion, J.; McBride, P.; Strauch, K.; Bartels, H.W.; Bienlein, J.K.; Brockmueller, K.; Jakubowski, Z.; Karch, K.; Kloiber, T.; Koch, W.; Maschmann, W.; Meyer, H.; Skwarnicki, T.; Trost, H.J.; Voigt, A.; Wachs, K.; Zschorsch, P.; Besset, D.; Cabenda, R.; Cowan, R.; Bieler, C.; Graaf, K.; Heinsius, F.H.; Kiel, T.; Krueger, S.; Lekebusch, R.; Nernst, R.; Sievers, D.; Stock, V.; Strohbusch, U.; Bloom, E.D.; Clare, R.; Cooper, S.; Fairfield, K.; Fridman, A.; Gaiser, J.; Gelphman, D.; Godfrey, G.; Hofstadter, R.; Kirkbride, I.; Lee, R.; Leffler, S.; Litke, A.M.; Lockman, W.; Lowe, S.; Niczyporuk, B.; Pollock, B.; Schwarz, A.; Tompkins, J.; Van Uitert, B.; Wacker, K.; Brock, I.; Engler, A.; Kraemer, R.W.; Marlow, D.; Messing, F.; Prindle, D.; Renger, B.; Rippich, C.; Vogel, H.; Cavalli-Sforza, M.; Coyne, D.; Folger, G.; Glaser, G.; Kobel, M.; Lurz, B.; Schuette, J.; Volland, U.; Wegener, H.; Janssen, H.; Koenig, A.C.; Metzger, W.J.; Reidenbach, M.; Schotanus, J.; Walle, R.T. van de; Walk, W.; Keh, S.; Kilian, H.; Koenigsmann, K.; Scheer, M.; Schmitt, P.; Marsiske, H.; Peck, C.; Porter, F.C.; Ratoff, P.; Williams, D.A.

1991-07-01

The Crystal Ball detector at the ε + ε - storage ring DORIS-II has been used to search for radiative B meson decays, especially of the type b→sγ. No mono-energetic γ-lines have been found in the inclusive photon spectrum from Υ(4S) decays, and upper limits are obtained for radiative decays of B mesons to various strange mesons and to the D*. Integrating the photon spectrum over the corresponding energy range, we find BR(B→γX) -3 at 90% confidence level for the mass range 892 MeV≤M X ≤2045 MeV. (orig.)

Quantum chromodynamics with infinite number of vector mesons

International Nuclear Information System (INIS)

Geshkenbejn, B.V.

1988-01-01

Families of vector mesons Ρ,Ψ,Υ, contain an infinite number of resonances with gradually increasing widths are considered. The asymptotic freedom requirement involves a relationship between the electric width of k-th resonance and its mass M k derivative over the number k. It is shown that for the families of Ψ and Υ mesons the moment from experimental function R(s) is equal to the sum of the moment from a bare quark loop and the edge term which stems from replacing of summation by integration. These equalities are fulfilled up to 1% for 60 moments in the Ψ-meson family and up to 2% for 96 moments in the Υ-meson family. The electronic widths of the resonances and the Ρ-meson mass are calculated. 7 refs

Is a charmed axial-vector meson already found

International Nuclear Information System (INIS)

Matsuda, S.

1976-12-01

A calculation is presented of the production rate via e + e - annihilation for a charmed p-wave meson of Jsup(P) = 1 + , based on a non-relativistic quark model of charmed hadrons. The results strongly suggest that the charmed axial-vector meson should be found copiously in association with a ground-state charmed meson. (author)

The mixing of scalar mesons and the baryon-baryon interaction

International Nuclear Information System (INIS)

Dai, L.R.

2011-01-01

By introducing the mixing of scalar mesons in the chiral SU(3) quark model, we dynamically investigate the baryon-baryon interaction. The hyperon-nucleon and nucleon-nucleon interactions are studied by solving the resonating group method (RGM) equation in a coupled-channel calculation. In our present work, the experimental lightest pseudoscalar π, K, η, η' mesons correspond exactly to the chiral nonet pseudoscalar fields π, K, η, η' in the chiral SU(3) quark model. The η, η' mesons are considered as the mixing of singlet and octet mesons, and the mixing angle θ ps is taken to be -23 . For scalar nonet mesons, we suppose that there exists a correspondence between the experimental lightest scalar f 0 (600), κ, a 0 (980), f 0 (980) mesons and the theoretical scalar nonet σ, κ, σ', ε fields in the chiral SU(3) quark model. For scalar mesons, we consider two different mixing cases: one is the ideal mixing and another is the θ s = 19 mixing. The masses of the σ' and ε mesons are taken to be 980MeV, which are just the masses of the experimental a 0 (980), f 0 (980) mesons. The mass of the σ meson is an adjustable parameter and is decided by fitting the binding energy of the deuteron, the masses of 560MeV and 644MeV are obtained for the ideal mixing and the θ s = 19 mixing, respectively. We find that, in order to reasonably describe the YN interactions, the mass of the κ meson is near 780MeV for the ideal mixing. However, we must enhance the mass of the κ meson for the θ s = 19 mixing, the 1050MeV is favorably used in the present work. The experimental σ and κ scalar mesons are very strange, both have larger widths. Hence, no matter what kind of mixing is considered, all the masses of scalar mesons we used in the present work seem to be consistent with the present PDG information. (orig.)

Search for scalar mesons

International Nuclear Information System (INIS)

Pennington, M.R.

1989-01-01

The search for I = 0 0 ++ mesons is described. The crucial role played by the states in the 1 GeV region is highlighted. An analysis program that with unimpeachable data would produce definitive results on these is outlined and shown with present data to provide prima facie evidence for dynamics beyond that of the quark model. The authors briefly speculate on the current status of the lowest mass scalar mesons and discuss how experiment can resolve the unanswered issues. 30 references, 6 figures, 1 table

Equality of e+e- production amplitudes for scalar-vector and pseudoscalar-axial heavy meson-antimeson pairs

Science.gov (United States)

Voloshin, M. B.

2018-02-01

The production of heavy meson-antimeson pairs of the type S V and P A in e+e- annihilation is considered, with P and V being the ground-state JP=0- and JP=1- (anti)mesons from the (1 /2 )-doublet and S and A standing for the excited JP=0+ and JP=1+ (anti)mesons from the (1 /2 )+doublet. It is argued that the production amplitudes in these two channels should be equal up to a higher (than one) order in the heavy quark mass (ΛQCD/MQ ) expansion, A (e +e-→S V ¯ )=A (e+e-→A P ¯ ) , including both the S -wave and the D -wave amplitudes. Given that the S V and P A thresholds are extremely close, the production cross section in both channels should be the same to a high degree of accuracy. In practice, this behavior can be studied for the processes e+e-→Ds 0(2317 )D¯s *+c .c . and e+e-→Ds 1(2460 )D¯ s+c .c . in the charm sector and e+e-→Bs 0B¯s *+c .c . and e+e-→Bs 1B¯ s+c .c . in the B sector.

Fock exchange in meson theories of nuclei

International Nuclear Information System (INIS)

Bolsterli, M.

1986-01-01

The Fock exchange term in meson field theories of nuclear systems is shown to arise from a two-loop ground-state self-energy diagram. Evaluation of this diagram gives the relativistic or semirelativistic analog of the Fock exchange energy; it differs from the nucleon-nucleon Fock energy in including retardation effects. In finite meson-field theories of nuclear systems, the variational nature of the meson-field analog of the Hartree-Fock energy functional can be further elucidated. 4 refs

Measurement of the D± meson cross section in DIS with the H1 detector at HERA

International Nuclear Information System (INIS)

Pahl, Philipp

2014-04-01

The inclusive production of D ± mesons in deep inelastic scattering at √(s)=318 GeV at HERA is studied using data taken with the Hl detector during the high energy measurement period in the years 2006 and 2007 corresponding to an integrated luminosity of 202.6 pb -1 . The visible phase space is defined by 5 2 2 , 0.05 T (D ± ) and -1.5 ± ) 2 is the photon virtuality, y is the inelasticity and p T (D ± ) and η(D ± ) are the transverse momentum and rapidity of the D ± meson. Charm production events are identified by the reconstruction of the D ± →K -+ π ± π ± decay channel. The sample is enhanced by the application of a multi-variate analysis technique using a multilayer perceptron. The input variables of the classifier are based on the specific energy loss of the kaon decay particle candidate and the reconstructed decay length of the D ± meson. The single and double differential cross sections are compared to leading and next-to-leading order QCD predictions.

On some rare weak decays of vector mesons

International Nuclear Information System (INIS)

Kurdadze, L.M.; Silagadze, Z.K.

2000-01-01

Some semileptonic weak decays of vector mesons are considered in the framework of the most popular quark models. Two the most popular models go give more elaborated estimates for the vector meson semileptonic decay rates are used. Unfortunately the predicted branching ratios are too small to make a study of these decays realistic at meson factories under construction [ru

Neutral and charged scalar mesons, pseudoscalar mesons, and diquarks in magnetic fields

Science.gov (United States)

Liu, Hao; Wang, Xinyang; Yu, Lang; Huang, Mei

2018-04-01

We investigate both (pseudo)scalar mesons and diquarks in the presence of external magnetic field in the framework of the two-flavored Nambu-Jona-Lasinio (NJL) model, where mesons and diquarks are constructed by infinite sum of quark-loop chains by using random phase approximation. The polarization function of the quark-loop is calculated to the leading order of 1 /Nc expansion by taking the quark propagator in the Landau level representation. We systematically investigate the masses behaviors of scalar σ meson, neutral and charged pions as well as the scalar diquarks, with respect to the magnetic field strength at finite temperature and chemical potential. It is shown that the numerical results of both neutral and charged pions are consistent with the lattice QCD simulations. The mass of the charge neutral pion keeps almost a constant under the magnetic field, which is preserved by the remnant symmetry of QCD ×QED in the vacuum. The mass of the charge neutral scalar σ is around two times quark mass and increases with the magnetic field due to the magnetic catalysis effect, which is an typical example showing that the polarized internal quark structure cannot be neglected when we consider the meson properties under magnetic field. For the charged particles, the one quark-antiquark loop contribution to the charged π± increases essentially with the increase of magnetic fields due to the magnetic catalysis of the polarized quarks. However, the one quark-quark loop contribution to the scalar diquark mass is negative comparing with the point-particle result and the loop effect is small.

Rare meson decays into very light neutralinos

Energy Technology Data Exchange (ETDEWEB)

Dreiner, H.K.; Grab, S. [Bonn Univ. (Germany). Bethe Center for Theoretical Physics und Physikalisches Inst.; Koschade, D. [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Physik; London Univ. (United Kingdom). Centre for Reserach in String Theory; Kraemer, M.; O' Leary, B. [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Physik; Langenfeld, U. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2009-05-15

We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the MSSM with and without minimal flavor violation. We present explicit formulae for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed. The branching ratios for kaon and B meson decays into light neutralinos may, however, be enhanced when one allows for non-minimal flavor violation. We find new constraints on the MSSM parameter space for such scenarios and discuss prospects for future kaon and B meson experiments. Finally, we comment on the search for light neutralinos in monojet signatures at the Tevatron and at the LHC. (orig.)

Meson exchange corrections in deep inelastic scattering on deuteron

International Nuclear Information System (INIS)

Kaptari, L.P.; Titov, A.I.

1989-01-01

Starting with the general equations of motion of the nucleons interacting with the mesons the one-particle Schroedinger-like equation for the nucleon wave function and the deep inelastic scattering amplitude with the meson-exchange currents are obtained. Effective pion-, sigma-, and omega-meson exchanges are considered. It is found that the mesonic corrections only partially (about 60%) restore the energy sum rule breaking because of the nucleon off-mass-shell effects in nuclei. This results contradicts with the prediction based on the calculation of the energy sum rule limited by the second order of the nucleon-meson vertex and static approximation. 17 refs.; 3 figs

Unified Chiral models of mesons and baryons

International Nuclear Information System (INIS)

Mendez-Galain, R.; Ripka, G.

1990-01-01

Unified Chiral models of mesons and baryons are presented. Emphasis is placed on the underlying quark structure of hadrons including the Skyrmion. The Nambu Jona-Lasinio model with vector mesons is discussed

Search for gluonic excitations in light unconventional mesons

Energy Technology Data Exchange (ETDEWEB)

Paul Eugenio

2007-07-01

Studies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenologicalmodels 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.

Sigma meson in heavy ion collision

International Nuclear Information System (INIS)

Cristian, Ivan; Fuchs, Christian

2004-01-01

We want to present a short theoretical prediction of the behaviour of the sigma meson in heavy ion collisions. It is considered that the sigma meson is a pion-pion correlation, resulting from the decay of the N*(1440) resonance. There will be presented some QMD simulations. (authors)

Old tensor mesons in QCD sum rules

International Nuclear Information System (INIS)

Aliev, T.M.; Shifman, M.A.

1981-01-01

Tensor mesons f, A 2 and A 3 are analyzed within the framework of QCD sum rules. The effects of gluon and quark condensate is accounted for phenomenologically. Accurate estimates of meson masses and coupling constants of the lowest-lying states are obtained. It is shown that the masses are reproduced within theoretical uncertainty of about 80 MeV. The coupling of f meson to the corresponding quark current is determined. The results are in good aqreement with experimental data [ru

Why do nucleons cling. [Meson theory

Energy Technology Data Exchange (ETDEWEB)

Kumar, N [Hindu Coll., Delhi (India)

1976-10-01

The nature of the forces which bind nucleons together within the nucleus of an atom have been discussed in detail. The characteristic properties of the nucleons, such as spin, interaction range etc. and the meson theory of nuclear forces are described. The present researches indicate that the force between two nucleons in a many-nucleon system is not very different from the force between two free nucleons. Researches related to the origin of nuclear forces based on the meson theory are now mainly concerned with the role played by the heavier mesons and the two pion exchanges in the middle region around 0.7 fm. (10/sup -13/ cm).

Single meson photoproduction and IR renormalons

International Nuclear Information System (INIS)

Agaev, S.S.

1996-10-01

Single pseudoscalar and vector mesons inclusive photoproduction γh → MX via higher twist mechanism is calculated using the QCD running coupling constant method. It is proved that in the context of this method a higher twist contribution to the photoproduction cross section cannot be normalized in terms of the meson electromagnetic form factor. The structure of infrared renormalon singularities of the higher twist subprocess cross section and the resumed expression (the Borel sum) for it are found. Comparisons are made with earlier results, as well as with leading twist cross section. Phenomenological effects of studied contributions for π, K, ρ-meson photoproduction are discussed. (author). 21 refs, 8 figs

Production and decay rates of the iota meson

International Nuclear Information System (INIS)

Frank, M.; O'Donnell, P.J.; Toronto Univ., Ontario

1984-01-01

We correlate the results for the mass spectrum of low lying isoscalar-pseudoscalar mesons with the production decay rates from J/psi->γP, with P=eta 1 , eta' 1 , eta 2 and iota and study the radiative decays of the iota meson. We conclude that the iota meson has to be interpreted as having a strong gluonium component. (orig.)

Development of fast and radiation hard Monolithic Active Pixel Sensors (MAPS) optimized for open charm meson detection with the CBM - vertex detector

International Nuclear Information System (INIS)

Deveaux, Michael

2008-01-01

The work presented in this thesis addresses a key issue of the CBM experiment at FAIR, which aims to study charm production in heavy ion collisions at energies ranging from 10 to 40 AGeV. For the first time in this kinematical range, open charm mesons will be used as a probe of the nuclear fireball. Despite of their short decay length, which is typically in the order of few 100 μm in the laboratory frame, those mesons will be identified by reconstructing their decay vertex. (orig.)

Development of fast and radiation hard Monolithic Active Pixel Sensors (MAPS) optimized for open charm meson detection with the CBM - vertex detector

Energy Technology Data Exchange (ETDEWEB)

Deveaux, Michael

2008-03-20

The work presented in this thesis addresses a key issue of the CBM experiment at FAIR, which aims to study charm production in heavy ion collisions at energies ranging from 10 to 40 AGeV. For the first time in this kinematical range, open charm mesons will be used as a probe of the nuclear fireball. Despite of their short decay length, which is typically in the order of few 100 {mu}m in the laboratory frame, those mesons will be identified by reconstructing their decay vertex. (orig.)

Elastic scattering and ω meson production near the threshold of π-p → ω + n

International Nuclear Information System (INIS)

Karami, H.; Carr, J.; Debenham, N.C.; Garbutt, D.A.; Jones, W.G.; Binnie, D.M.; Keyne, J.; Moissidis, P.; Sarma, H.N.; Siotis, I.

1979-01-01

Measurements are reported of the differential cross section for the reaction π - +p → ω + n from threshold to a final-state c.m. momentum P* of 200 MeV/c. The previously reported fall in total cross section sigma/P* below about 100 MeV/c is again seen. The differential cross section remains close to isotropic over the entire range. A parallel experiment on the variation in the elastic differential cross section across the threshold shows evidence of this threshold. The elastic data cover a range of incident moments from 1010 to 1180 MeV/c in steps of 5 MeV/c. (Auth.)

The mixing of scalar mesons and the baryon-baryon interaction

Energy Technology Data Exchange (ETDEWEB)

Dai, L.R. [Liaoning Normal University, Department of Physics, Dalian (China)

2011-02-15

By introducing the mixing of scalar mesons in the chiral SU(3) quark model, we dynamically investigate the baryon-baryon interaction. The hyperon-nucleon and nucleon-nucleon interactions are studied by solving the resonating group method (RGM) equation in a coupled-channel calculation. In our present work, the experimental lightest pseudoscalar {pi}, K, {eta}, {eta}' mesons correspond exactly to the chiral nonet pseudoscalar fields {pi}, K, {eta}, {eta}' in the chiral SU(3) quark model. The {eta}, {eta}' mesons are considered as the mixing of singlet and octet mesons, and the mixing angle {theta}{sub ps} is taken to be -23 . For scalar nonet mesons, we suppose that there exists a correspondence between the experimental lightest scalar f{sub 0}(600), {kappa}, a{sub 0}(980), f{sub 0}(980) mesons and the theoretical scalar nonet {sigma}, {kappa}, {sigma}', {epsilon} fields in the chiral SU(3) quark model. For scalar mesons, we consider two different mixing cases: one is the ideal mixing and another is the {theta}{sub s} = 19 mixing. The masses of the {sigma}' and {epsilon} mesons are taken to be 980MeV, which are just the masses of the experimental a{sub 0}(980), f{sub 0}(980) mesons. The mass of the {sigma} meson is an adjustable parameter and is decided by fitting the binding energy of the deuteron, the masses of 560MeV and 644MeV are obtained for the ideal mixing and the {theta}{sub s} = 19 mixing, respectively. We find that, in order to reasonably describe the YN interactions, the mass of the {kappa} meson is near 780MeV for the ideal mixing. However, we must enhance the mass of the {kappa} meson for the {theta}{sub s} = 19 mixing, the 1050MeV is favorably used in the present work. The experimental {sigma} and {kappa} scalar mesons are very strange, both have larger widths. Hence, no matter what kind of mixing is considered, all the masses of scalar mesons we used in the present work seem to be consistent with the present PDG information

Photoproduction of the φ(1020) near threshold in CLAS

International Nuclear Information System (INIS)

Tedeschi, D.J.

2002-01-01

The differential cross section for the photoproduction of the φ (1020) near threshold (E γ = 1.57GeV) is predicted to be sensitive to production mechanisms other than diffraction. However, the existing low energy data is of limited statistics and kinematical coverage. Complete measurements of φ meson production on the proton have been performed at The Thomas Jefferson National Accelerator Facility using a liquid hydrogen target and the CEBAF Large Acceptance Spectrometer (CLAS). The φ was identified by missing mass using a proton and positive kaon detected by CLAS in coincidence with an electron in the photon tagger. The energy of the tagged, bremsstrahlung photons ranged from φ-threshold to 2.4 GeV. A description of the data set and the differential cross section for (E γ = 2.0 GeV) will be presented and compared with present theoretical calculations. (author)

Tensor meson dominance and e/sup +/e/sup -/-physics

Energy Technology Data Exchange (ETDEWEB)

Genz, H [Miami Univ., Coral Gables, FL (USA). Center for Theoretical Studies; Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik); Mallik, S [Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik

1983-01-01

The phenomenological status of tensor meson dominance is reported. Some new results concerning hadronic decays of the 2/sup + +/-meson chi/sub 2/(3.55) and the heavy lepton tau are also included. Considering experimental errors, tensor meson dominance is in agreement with experiment.

Radiative decays of vector mesons in the chiral bag model

International Nuclear Information System (INIS)

Tabachenko, A.N.

1988-01-01

A new model of radiative π-meson decays of vector mesons in the chiral bag model is proposed. The quark-π-meson interaction has the form of a pseudoscalar coupling and is located on the bag surface. The vector meson decay width depends on the quark masses, the π-meson decay constant, the radius of the bag, and the free parameter Z 2 , which specifies the disappearance of the bag during the decay. The obtained results for the omega- and p-decay widths are in satisfactory agreement with the experiment

Inclusive spectra of hadrons in B-meson decays

International Nuclear Information System (INIS)

Dobrovol'skaya, A.V.; Ter-Martirosyan, K.A.; Zoller, V.R.

1989-01-01

The inclusive spectra of hadrons (mainly pions) produced in the semileptonic and nonleptonic decays of B-mesons are calculated. Parameters of spectra for different types of hard qq-bar-strings, appearing in the B-meson decays, are determined using the data on e+e-annihilation. Numerical results for B-meson decay induced by both b→b and b→u transitions are presented. 10 refs.; 5 figs

Meson Spectroscopy in the Light Quark Sector

Science.gov (United States)

De Vita, R.

2014-03-01

Understanding the hadron spectrum is one of the fundamental issues in modern particle physics. We know that existing hadron configurations include baryons, made of three quarks, and mesons, made of quark-antiquark pairs. However most of the mass of the hadrons is not due to the mass of these elementary constituents but to their binding force. Studying the hadron spectrum is therefore a tool to understand one of the fundamental forces in nature, the strong force, and Quantum Chromo Dynamics (QCD), the theory that describes it. This investigation can provide an answer to fundamental questions as what is the origin of the mass of hadrons, what is the origin of quark confinement, what are the relevant degrees of freedom to describe these complex systems and how the transition between the elementary constituents, quarks and gluons, and baryons and mesons occurs. In this field a key tool is given by meson spectroscopy. Mesons, being made by a quark and an anti-quark, are the simplest quark bound system and therefore the ideal benchmark to study the interaction between quarks and understand what the role of gluons is. In this investigation, it is fundamental to precisely determine the spectrum and properties of mesons but also to search for possible unconventional states beyond the qbar q configuration as tetraquarks (qqoverline{qq}), hybrids (qbar qg) and glueballs. These states can be distinguished unambiguously from regular mesons when they have exotic quantum numbers, i.e. combinations of total angular momentum, spin and parity that are not allowed for qbar q states. These are called exotic quantum numbers and the corresponding states are referred to as exotics. The study of the meson spectrum and the search for exotics is among the goals of several experiments in the world that exploit different reaction processes, as e+e- annihilation, pbar p annihilation, pion scattering, proton-proton scattering and photo-production, to produce meson states. This intense effort is

Multistrange Meson-Baryon Dynamics and Resonance Generation

Science.gov (United States)

Khemchandani, K. P.; Martínez Torres, A.; Hosaka, A.; Nagahiro, H.; Navarra, F. S.; Nielsen, M.

2018-05-01

In this talk I review our recent studies on meson-baryon systems with strangeness - 1 and - 2. The motivation of our works is to find resonances generated as a consequence of coupled channel meson-baryon interactions. The coupled channels are all meson-baryon systems formed by combining a pseudoscalar or a vector meson with an octet baryon such that the system has the strange quantum number equal to - 1 or - 2. The lowest order meson-baryon interaction amplitudes are obtained from Lagrangians based on the chiral and the hidden local symmetries related to the vector mesons working as the gauge bosons. These lowest order amplitudes are used as an input to solve the Bethe-Salpeter equation and a search for poles is made in the resulting amplitudes, in the complex plane. In case of systems with strangeness - 1, we find evidence for the existence of some hyperons such as: Λ(2000), Σ(1750), Σ(1940), Σ(2000). More recently, in the study of strangeness - 2 systems we have found two narrow resonances which can be related to Ξ (1690) and Ξ(2120). In this latter work, we have obtained the lowest order amplitudes relativistically as well as in the nonrelativistic approximation to solve the scattering equations. We find that the existence of the poles in the complex plane does not get affected by the computation of the scattering equation with the lowest order amplitudes obtained in the nonrelativistic approximation.

Method of taking into account meson and quark-gluon degrees of freedom in hadron-hadron interactions at low and intermediate energies. Application to NN scattering

International Nuclear Information System (INIS)

Safronov, A.N.

1983-01-01

A system of nonsingular integral equations is formulated for the calculation of hadron-hadron partial amplitudes in the low-and intermediate-energy range taking into account meson and quark-gluon degrees of freedom. The quark-gluon degrees of freedom are included in the framework of the composite-quark-bag model, and the meson degrees of freedom are treated by the methods of the relativistic quantum field theory. It is shown that including the quark-gluon degrees of freedom leads to suppression of meson exchange effects, mostly of heavy meson (rho, ω) exchanges. The method has been applied to the calculation of the 3 S 1 , 1 S 0 , 3 P 0 , 3 P 1 , and 1 P 1 phase shifts for the nucleon-nucleon scattering at the incident nucleon energies T=0-1050 MeV, as well as to the S-wave scattering lengths and effective radii

Relativistic meson spectroscopy in momentum space

International Nuclear Information System (INIS)

Hersbach, H.

1994-01-01

In this paper a relativistic constituent-quark model based on the Ruijgrok--de Groot formalism is presented. The quark model is not defined in configuration space, but in momentum space. The complete meson spectrum, with the exception of the self-conjugate light unflavored mesons, is calculated. The potential used consists of a one-gluon exchange (OGE) part and a confining part. For the confining part a relativistic generalization of the linear plus constant potential was used, which is well defined in momentum space without introducing any singularities. For the OGE part several potentials were investigated. Retardations were included at all places. By the use of a fitting procedure involving 52 well-established mesons, but results were obtained for a potential consisting of a purely vector Richardson potential and a purely scalar confining potential. Reasonable results were also obtained for a modified Richardson potential. Most meson masses, with the exception of the π, the K, and the K 0 * , were found to be quite well described by the model

Asymptotics of Heavy-Meson Form Factors

CERN Document Server

Grozin, A.G.; Grozin, Andrey G.; Neubert, Matthias

1997-01-01

Using methods developed for hard exclusive QCD processes, we calculate the asymptotic behaviour of heavy-meson form factors at large recoil. It is determined by the leading- and subleading-twist meson wave functions. For $1\\ll |v\\cdot v'|\\ll m_Q/\\Lambda$, the form factors are dominated by the Isgur--Wise function, which is determined by the interference between the wave functions of leading and subleading twist. At $|v\\cdot v'|\\gg m_Q/\\Lambda$, they are dominated by two functions arising at order $1/m_Q$ in the heavy-quark expansion, which are determined by the leading-twist wave function alone. The sum of these contributions describes the form factors in the whole region $|v\\cdot v'|\\gg 1$. As a consequence, there is an exact zero in the form factor for the scattering of longitudinally polarized $B^*$ mesons at some value $v\\cdot v'\\sim m_b/\\Lambda$, and an approximate zero in the form factor of $B$ mesons in the timelike region ($v\\cdot v'\\sim -m_b/\\Lambda$). We obtain the evolution equations and sum rules ...

C(1480) meson and electromagnetic processes

International Nuclear Information System (INIS)

Landsberg, L.G.

1992-01-01

Possible processes of production of the vector meson C(1480) → var-phi π, a candidate for exotic states, in electromagnetic processes are considered [photoproduction, e + e - →C(1480) → var-phi π 0 , and the reaction of production of C(1480) in the Coulomb field of a nucleus]. It is shown that coherent Coulomb production of the C(1480) meson allows one to determine the absolute value of BR[C(1480) → var-phi π], which is essential for the interpretation of the nature of this hadron. Possibilities of observing C(1480) mesons in e + e - collisions at the var-phi factory DAΦNE are studied. 27 refs., 12 figs., 1 tab

Radiative decay of light and heavy mesons

International Nuclear Information System (INIS)

Barik, N.; Dash, P.C.

1994-01-01

The M1 transition among the vector (V) and pseudoscalar (P) mesons in the light and heavy flavor sectors has been investigated in a potential model of independent quarks. Going beyond the static approximation, to add some momentum dependence due to the recoil effect in a more realistic calculation, we find an improvement in the results for the radiative decay of light flavored mesons. However, our prediction on the decay rates for the mesons (D * and B * ) in the heavy flavor sector remains unaffected and compares well with those of other model calculations

In-medium meson properties and screening correlators

International Nuclear Information System (INIS)

Bazavov, A; Karsch, F; Mukherjee, Swagato; Petreczky, P; Maezawa, Y

2014-01-01

We study spatial meson correlation functions consisting of strange quarks, strange and charm quarks and charm quarks in (2 + 1)-flavor QCD using the highly improved staggered quark action. We find that the in-medium modification of the meson correlators decreases with increasing charm quark content and decreasing size. In particular, we find strong in-medium modification of φ and D s meson correlators around the chiral transition temperature T c , while J/ψ and η c correlators show strong in-medium modification only at temperatures of 1.4T c .

Theories of the eta-meson-nucleus interaction

International Nuclear Information System (INIS)

Liu, L.C.

1994-01-01

It is sown that the pion-nucleon elastic scattering, eta-nucleon scattering length and the cross sections for pion-induced eta production on a nucleon satisfy a set of consistency relations. These relations are used to examine the ηN scattering lengths given by the various models. The nature of the threshold ηN interaction is discussed and recent advancements in ηN interaction is discussed and recent advancements in η-nucleus reaction theory are reviewed

Review of meson resonance radiative decays

International Nuclear Information System (INIS)

Thorndike, E.H.

1977-01-01

The radiative decays of meson resonances can be studied by three different approaches, it is noted. These are the meson-exchange, Primakoff effect, and the production of the desired resonance and subsequent observation of its decay. These approaches are criticized and examples of them are reviewed. Mass distributions are shown and branching ratios discussed. 21 references

Meson masses and decay constants from unquenched lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); McNeile, C. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Michael, C. [Liverpool Univ. (United Kingdom). Theoretical Physics Div., Dept. of Mathematical Sciences; Urbach, C. [Humboldt Univ. Berlin (Germany). Inst. fuer Physik

2009-06-15

We report results for the masses of the flavour non-singlet light 0{sup ++}, 1{sup --}, and 1{sup +-} mesons from unquenched lattice QCD at two lattice spacings. The twisted mass formalism was used with two flavours of sea quarks. For the 0{sup ++} and 1{sup +-} mesons we look for the effect of decays on the mass dependence. For the light vector mesons we study the chiral extrapolations of the mass. We report results for the leptonic and transverse decay constants of the meson. We test the mass dependence of the KRSF relations. (orig.)

Meson masses and decay constants from unquenched lattice QCD

International Nuclear Information System (INIS)

Jansen, K.; McNeile, C.; Michael, C.; Urbach, C.

2009-06-01

We report results for the masses of the flavour non-singlet light 0 ++ , 1 -- , and 1 +- mesons from unquenched lattice QCD at two lattice spacings. The twisted mass formalism was used with two flavours of sea quarks. For the 0 ++ and 1 +- mesons we look for the effect of decays on the mass dependence. For the light vector mesons we study the chiral extrapolations of the mass. We report results for the leptonic and transverse decay constants of the meson. We test the mass dependence of the KRSF relations. (orig.)

Inclusive decays of the B meson and possible life-time difference between Bd0 and B± mesons

International Nuclear Information System (INIS)

Tanimoto, Morimitsu

1992-01-01

We study branching ratios of the inclusive semileptonic decay and the inclusive anti ccanti s decay of the B meson in the spectator model, focusing on the life-time difference between B d 0 and B + mesons. In the case of τsub(B ± )/τsub(B d 0 )=1, it is impossible to get the branching ratio below 12% for B→eνX without going over 20% for B→anti ccanti s, which is unfavored by the inclusive K - decay of the B meson. It is found that the sizable life-time difference leads to the reasonable inclusive semileptonic decay rate and the inclusive anti ccanti s decay rate. (orig.)

Observation and study of bottom-meson decays to a charm meson, a proton-antiproton pair, and pions

Energy Technology Data Exchange (ETDEWEB)

Hong, Tae Min [Univ. of California, Santa Barbara, CA (United States)

2010-04-27

Bottom-meson decays with baryons show two unusual features—the branching fractions are enhanced for multibody decays and the baryon-antibaryon subsystem recoils against the other decay products—and their reasons are not yet well understood. Moreover, measurements using explicit reconstruction techniques constitute only about 1% out of about 8% of such decays. This Dissertation reports the study of ten bottom-meson decays (labeled 0– 9) to a proton-antiproton pair, a charm meson, and a system of up to two pions, using the BABAR Experiment’s 455×10⁶ BB pairs produced with the PEP-II asymmetric-energy e⁺e^- collider at the Stanford Linear Accelerator Center.

CORNELL: CLEO discovers B meson penguins

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-06-15

The CLEO collaboration at Cornell's CESR electron-positron storage ring has discovered a rare type of B meson decay in which only a high energy photon and a K* meson are produced. These decays provide the first unambiguous evidence for an alternative route for heavy quark decay that has been given the whimsical name ''penguin diagram''. In the mid-1970s penguin diagrams were proposed to explain the puzzling strangeness quantum number selection rules in the decay of K mesons. At the same time it was realized that penguin diagrams could also be important in the CP violation seen in neutral K meson decay. CP violation, an asymmetry between matter and antimatter, is an essential ingredient in understanding why there is much more matter than antimatter in the universe. CP violation introduces a definite direction to the arrow of time, which could otherwise point equally forwards or backwards. In addition, penguin decays are very sensitive to some extensions of the Standard Model of weak decay. Although penguin diagrams were first proposed to explain an effect in K meson decay, the K system gives no unique signature for them, and verification of penguin processes meant looking elsewhere. In the Standard Model, quarks decay under the influence of the weak force, emitting a W boson. Since the W is charged, the charge of the initial quark differs from that of the final quark, so the charge of the quark changes as well as its flavour.

Medium modifications of mesons. Chiral symmetry restoration, in-medium QCD sum rules for D and ρ mesons, and Bethe-Salpeter equations

Energy Technology Data Exchange (ETDEWEB)

Hilger, Thomas Uwe

2012-04-11

The interplay of hadron properties and their modification in an ambient nuclear medium on the one hand and spontaneous chiral symmetry breaking and its restoration on the other hand is investigated. QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D- anti D and B- anti B mesons as a function of the nuclear matter density and investigate the impact of various condensates in linear density approximation. The analysis also includes D{sub s} and D{sup *}{sub 0} mesons. QCD sum rules for chiral partners in the open-charm meson sector are presented at nonzero baryon net density or temperature. We focus on the differences between pseudo-scalar and scalar as well as vector and axial-vector D mesons and derive the corresponding Weinberg type sum rules. Based on QCD sum rules we explore the consequences of a scenario for the ρ meson, where the chiral symmetry breaking condensates are set to zero whereas the chirally symmetric condensates remain at their vacuum values. The complementarity of mass shift and broadening is discussed. An alternative approach which utilizes coupled Dyson-Schwinger and Bethe-Salpeter equations for quark-antiquark bound states is investigated. For this purpose we analyze the analytic structure of the quark propagators in the complex plane numerically and test the possibility to widen the applicability of the method to the sector of heavy-light mesons in the scalar and pseudo-scalar channels, such as the D mesons, by varying the momentum partitioning parameter. The solutions of the Dyson-Schwinger equation in the Wigner-Weyl phase of chiral symmetry at nonzero bare quark masses are used to investigate a scenario with explicit but without dynamical chiral symmetry breaking.

Nuclear molecular halo: the ubiquitous occurrence of van der Waals molecular states near threshold in molecular, nuclear and particle physics

International Nuclear Information System (INIS)

Gai, Moshe

1999-01-01

The observation of large E1 strength near threshold in the electromagnetic dissociation of 11 Li poses a fundamental question: Is the large E1 strength due to the threshold or is it due to a low lying E1 state? Such molecular cluster states were observed in 18 O and in several nuclei near the drip line. We discuss the nature of the threshold effect as well as review the situation in Molecular (and Particle Physics) where such Molecular States are observed near the dissociation limit. We suggest that the situation in 11 Li is reminiscent of the argon-benzene molecule where the argon atom is loosely bound by a polarization (van der Waals) mechanism and thus leads to a very extended object lying near the dissociation limit. Such states are also suggested to dominate the structure of mesons [α 0 (980), f 0 (975)] and baryons [λ(1405)] with proposed Kaon molecular structure (Dalitz) near threshold. The inspection of such states throughout Physics allows us to gain insight into this phenomenon and suggest that a new collective Molecular Dipole Degree of Freedom plays a major role in the structure of hadrons (halo nuclei, mesons and baryons), and that quantitative tools such as the E1 Molecular Sum Rule are useful for elucidating the nature of the observed low lying E1 strength in halo nuclei. (author)

Prompt $D^0$ meson $v_n$ harmonics in PbPb collisions at 5.02 TeV

CERN Document Server

Sun, Jian

2016-01-01

Because of their large mass, heavy quarks are produced primarily at early stages of heavy-ion collisions, and therefore experience the full evolution of the system and carry information about the extent of thermalization of the QGP. Azimuthal anisotropy parameters ($v_n$) of charm and bottom hadrons provide unique information about the path length dependent interactions between heavy quarks and the medium. To what extent heavy quarks at low $p_T$ flow with the medium is a good measure of the interaction strength. At high $p_T$, $v_2$ and $v_3$ from path length dependent energy loss provide a powerful tool to study heavy quark energy loss mechanisms. With the large PbPb data sample at 5.02 TeV collected by the CMS detector during the 2015 LHC run, azimuthal anisotropy $v_2$ and $v_3$ of D0 meson is measured over a wide $p_T$ range and at different centralities. In this talk, new results of D0 meson $v_n$ parameters are presented, and compared to the charged hadron $v_n$ at the same energy and the latest theore...

Meson phase space density from interferometry

International Nuclear Information System (INIS)

Bertsch, G.F.

1993-01-01

The interferometric analysis of meson correlations a measure of the average phase space density of the mesons in the final state. The quantity is a useful indicator of the statistical properties of the systems, and it can be extracted with a minimum of model assumptions. Values obtained from recent measurements are consistent with the thermal value, but do not rule out superradiance effects

Vector mesons on the light front

International Nuclear Information System (INIS)

Naito, K.; Maedan, S.; Itakura, K.

2004-01-01

We apply the light-front quantization to the Nambu-Jona-Lasinio model with the vector interaction, and compute vector meson's mass and light-cone wavefunction in the large N limit. Following the same procedure as in the previous analyses for scalar and pseudo-scalar mesons, we derive the bound-state equations of a qq-bar system in the vector channel. We include the lowest order effects of the vector interaction. The resulting transverse and longitudinal components of the bound-state equation look different from each other. But eventually after imposing an appropriate cutoff, one finds these two are identical, giving the same mass and the same (spin-independent) light-cone wavefunction. Mass of the vector meson decreases as one increases the strength of the vector interaction

Composite vector mesons and string models

International Nuclear Information System (INIS)

Mandelstam, S.

1985-01-01

The author discusses the general question of gauge mesons in extended supergravities, and whether such theories can produce the gauge mesons corresponding to a group at least as large as SU(3) x SU(2) x U(1). An exciting conjecture in this direction was made a few years ago by previous authors, who suggested that there might be composite SU(8) gauge mesons in a supergravity model known as the N=8 model. Until we have a consistent, renormalizable theory of supergravity we cannot really obtain any indication of the truth or falseness of that conjecture. One form of the Neveu-Schwarz string model has been shown to be a theory of supergravity; it is finite at the one-loop level and probably in any order of perturbation theory. The discussion is within the framework of this model. The author questions whether massive vector mesons can possibly lose their mass due to interactions. Arguments have been given on both sides of this question, and the author believes that this can occur under certain circumstances. Our conclusions is that the FNNS mechanism will create a gauge symmetry in addition to the rigid symmetry

High statistics inclusive φ meson production at SPS energies

International Nuclear Information System (INIS)

Dijkstra, H.; Belau, E.

1986-01-01

Inclusive φ meson production has been measured for 100 GeV/c and 200 GeV/c incident π - , anti p and K - , and for 120 GeV/c and 200 GeV/c incident π + , p and K + , using a Be target. A total of 630,000 φ mesons has been recorded in the kinematic range 0 F F and dσ/dp T 2 . The longitudinal momentum distributions show that the strange valence quarks of the incident K mesons play an important role in φ meson production, even at small x F . The decay angular distribution of the φ meson is evaluated in the Gottfried-Jackson frame and is expressed in the elements of the density matrix. There is a small but significant cos 2 θ GJ dependence for small p T , which decreases for increasing p T . (Auth.)

Evidence for a backward peak in the γd→π0d cross section near the η threshold

International Nuclear Information System (INIS)

Ilieva, Y.; Berman, B.L.; Strakovsky, I.I.; Benmouna, N.; Briscoe, W.J.; Feldman, G.; Munevar, E.; Nadel-Turonski, P.; Tkabladze, A.; Kudryavtsev, A.E.; Tarasov, V.E.; Bedlinskiy, I.; Kossov, M.; Kuleshov, S.V.; Mikhailov, K.; Pivnyuk, N.; Pogorelko, O.; Pozdniakov, S.; Serov, V.S.; Stavinsky, A.; Vlassov, A.V.; Amarian, M.; Bagdasaryan, H.; Bueltmann, S.; Careccia, S.L.; Dodge, G.E.; Gavalian, G.; Guler, N.; Hyde-Wright, C.E.; Juengst, H.G.; Kalantarians, N.; Klein, A.; Kuhn, S.E.; Lachniet, J.; Niroula, M.R.; Tkachenko, S.; Weinstein, L.B.; Zhang, J.; Ambrozewicz, P.; Gonenc, A.; Moteabbed, M.; Anghinolfi, M.; Battaglieri, M.; De Vita, R.; Ricco, G.; Ripani, M.; Stoler, P.; Taiuti, M.; Asryan, G.; Egiyan, K.S.; Avakian, H.; Boiarinov, S.; Brooks, W.K.; Burkert, V.D.; Carman, D.S.; Degtyarenko, P.V.; Deur, A.; Egiyan, H.; Elouadrhiri, L.; Guo, L.; Gyurjyan, V.; Ito, M.M.; Laget, J.M.; Mecking, B.A.; Mestayer, M.D.; Niczyporuk, B.B.; Niyazov, R.A.; Nozar, M.; Sapunenko, V.; Sharabian, Y.G.; Smith, E.S.; Stepanyan, S.; Thoma, U.; Weygand, D.P.; Wolin, E.; Yegneswaran, A.; Baillie, N.; Butuceanu, C.; Funsten, H.; Griffioen, K.A.; Ball, J.P.; Collins, P.; Dugger, M.; Pasyuk, E.; Ritchie, B.G.; Baltzell, N.A.; Djalali, C.; Dzyubak, O.P.; Gothe, R.W.; Langheinrich, J.; Lu, H.; Nasseripour, R.; Strauch, S.; Tedeschi, D.J.; Tur, C.; Wood, M.H.; Zhao, Z.; Batourine, V.; Kim, W.; Park, K.; Stepanyan, S.S.; Bellis, M.; Bradford, R.; Dickson, R.; Krahn, Z.; Kuhn, J.; Meyer, C.A.; Moriya, K.; Schumacher, R.A.; Williams, M.; Biselli, A.S.; Bouchigny, S.; Guidal, M.; Jo, H.S.; MacCormick, M.; Niccolai, S.; Branford, D.; Watts, D.P.; Calarco, J.R.; Hersman, F.W.; Holtrop, M.; Zana, L.; Chen, S.; Coltharp, P.; Crede, V.; Eugenio, P.; Ostrovidov, A.I.; Stokes, B.E.; Cole, P.L.; Crabb, D.; Pierce, J.; Prok, Y.; Smith, L.C.; De Masi, R.; Garcon, M.; Girod, F.X.; Sabatie, F.; De Sanctis, E.; Mirazita, M.; Ronchetti, F.; Rossi, P.; Donnelly, J.; Ireland, D.G.; Kellie, J.D.; Livingston, K.; McKinnon, B.; Paterson, C.; Protopopescu, D.; Rosner, G.; Doughty, D.; Fedotov, G.; Ishkhanov, B.S.; Isupov, E.L.; Mokeev, V.; Shvedunov, N.V.; Gilfoyle, G.P.; Giovanetti, K.L.; Niculescu, G.; Niculescu, I.; Goetz, J.T.; Hafidi, K.; Hakobyan, R.S.; Klein, F.J.; Sober, D.I.; Hicks, K.; Hleiqawi, I.; Mibe, T.; Jenkins, D.; Joo, K.; Markov, N.; Ungaro, M.; Zhao, B.; Khandaker, M.; Salgado, C.; Kramer, L.H.; Raue, B.A.; Kubarovsky, V.; Lawrence, D.; Miskimen, R.; Morrow, S.A.; Mutchler, G.S.; Osipenko, M.; Price, J.W.; Santoro, J.P.; Vineyard, M.F.

2010-01-01

High-quality cross sections for the reaction γd→π 0 d have been measured using the CLAS at Jefferson Lab over a wide energy range near and above the η-meson photoproduction threshold. At backward c.m. angles for the outgoing pions, we observe a resonance-like structure near E γ =700 MeV. Our model analysis shows that it can be explained by η excitation in the intermediate state. The effect is the result of the contribution of the N(1535)S 11 -resonance to the amplitudes of the subprocesses occurring between the two nucleons and of a two-step process in which the excitation of an intermediate η-meson dominates. (orig.)

Observation of a backward peak in the gamma d ---> pi0 d cross- section near the eta threshold

Energy Technology Data Exchange (ETDEWEB)

Yordanka Ilieva; Barry Berman; Alexander Kudryavtsev; I.I. Strakovsky; V.E. Tarasov; Moscov Amaryan; Pawel Ambrozewicz; Marco Anghinolfi; G. Asryan; Harutyun Avakian; Hovhannes Baghdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Matthew Bellis; Nawal Benmouna; Angela Biselli; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Volker Crede; R. De Masi; Enzo De Sanctis; Raffaella De Vita; Pavel Degtiarenko; Alexandre Deur; Richard Dickson; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Kawtar Hafidi; Rafael Hakobyan; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde; Charles Hyde-Wright; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; Narbe Kalantarians; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Mikhail Kossov; Zebulun Krahn; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; David Lawrence; Kenneth Livingston; Haiyun Lu; Marion MacCormick; Nikolai Markov; Bryan McKinnon; Bernhard Mecking; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Marco Mirazita; Rory Miskimen; Viktor Mokeev; Kei Moriya; Steven Morrow; M. Moteabbed; E. Munevar; Gordon Mutchler; Pawel Nadel-Turonski; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; K. Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Oleg Pogorelko; S. Pozdniakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Paul Stoler; Steffen Strauch; Mauro Taiuti; David Tedeschi; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

2007-05-14

High-quality cross sections for the reaction gamma+d->pi^0+d have been measured using the CLAS at Jefferson Lab over a wide energy range near and above the eta-meson photoproduction threshold. At backward c.m. angles for the outgoing pions, we observe a resonance-like structure near E_gamma=700 MeV. Our model analysis shows that it can be explained by eta excitation in the intermediate state. The effect is the result of the contribution of the N(1535)S_11 resonance to the amplitudes of the subprocesses occurring between the two nucleons and of a two-step process in which the excitation of an intermediate eta meson dominates.

CORNELL: CLEO discovers B meson penguins

International Nuclear Information System (INIS)

Anon.

1993-01-01

The CLEO collaboration at Cornell's CESR electron-positron storage ring has discovered a rare type of B meson decay in which only a high energy photon and a K* meson are produced. These decays provide the first unambiguous evidence for an alternative route for heavy quark decay that has been given the whimsical name ''penguin diagram''. In the mid-1970s penguin diagrams were proposed to explain the puzzling strangeness quantum number selection rules in the decay of K mesons. At the same time it was realized that penguin diagrams could also be important in the CP violation seen in neutral K meson decay. CP violation, an asymmetry between matter and antimatter, is an essential ingredient in understanding why there is much more matter than antimatter in the universe. CP violation introduces a definite direction to the arrow of time, which could otherwise point equally forwards or backwards. In addition, penguin decays are very sensitive to some extensions of the Standard Model of weak decay. Although penguin diagrams were first proposed to explain an effect in K meson decay, the K system gives no unique signature for them, and verification of penguin processes meant looking elsewhere. In the Standard Model, quarks decay under the influence of the weak force, emitting a W boson. Since the W is charged, the charge of the initial quark differs from that of the final quark, so the charge of the quark changes as well as its flavour

Quark-gluon mixing in scalar mesons

International Nuclear Information System (INIS)

Eremyan, Sh.S.; Nazaryan, A.E.

1986-01-01

Scalar mesons are considered within the quark-gluon mixing model. It is shown that there exists decouplet of scalar particles consisting of S* (975), ε (1400), S*' (1700), δ (980) and κ (1350) resonances. It has turned out that the long ago known S* (975)-resonance is a nearly pure glouball. A good description of all available experimental data on scalar meson decays is obtained

Bs mesons: semileptonic and nonleptonic decays

Directory of Open Access Journals (Sweden)

Albertus C.

2014-01-01

Full Text Available In this contribution we compute some nonleptonic and semileptonic decay widths of Bs mesons, working in the context of constituent quark models [1, 2]. For the case of semileptonic decays we consider reactions leading to kaons or different Jπ Ds mesons. The study of nonleptonic decays has been done in the factorisation approximation and includes the final states enclosed in Table 2.

SU(4) flavor symmetry breaking in D-meson couplings to light hadrons

Energy Technology Data Exchange (ETDEWEB)

Fontoura, C.E. [Instituto Tecnologico da Aeronautica, DCTA, Sao Jose dos Campos, SP (Brazil); Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil); Haidenbauer, J. [Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Forschungszentrum Juelich, Juelich (Germany); Krein, G. [Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil)

2017-05-15

The validity of SU(4)-flavor symmetry relations of couplings of charmed D-mesons to light mesons and baryons is examined with the use of {sup 3}P{sub 0} quark-pair creation model and nonrelativistic quark-model wave functions. We focus on the three-meson couplings ππρ, KKρ and DDρ and baryon-baryon-meson couplings NNπ, NΛK and NΛ{sub c}D. It is found that SU(4)-flavor symmetry is broken at the level of 30% in the DDρ tree-meson couplings and 20% in the baryon-baryon-meson couplings. Consequences of these findings for DN cross sections and existence of bound states D-mesons in nuclei are discussed. (orig.)

Study of light mesons with WASA-at-COSY

Science.gov (United States)

Prencipe, Elisabetta

2014-06-01

The WASA detector, operating at the COSY facility in Jülich (Germany) has been collecting data since 2007. The experiment allows to perform studies of light mesons, such as π0, η and ω rare decay processes, in order to perform precise measurements of branching ratios, determine Dalitz plot parameters, test symmetry and symmetry breaking, and evaluate transition form factors. In the experiments a proton or deuteron beam impinged on a pellet target of hydrogen or deuterium, which allows the reactions proton-proton (pp) or proton-deuteron (pd). A high-statistics sample of η mesons has been collected: in the reaction pd →3He η, 3×107η mesons were tagged at a beam energy of 1.0 GeV, while 5×108η mesons were produced in the reaction pp → ppη at 1.4 GeV. This corresponds to the production of 10 η/s and 100 η/s, respectively, for the two reaction processes. In the pp dataset a higher background level is found compared to the pd data set. In both cases, we identify the η mesons by means of the missing mass derived from the recoil particles. A kinematic fit largely rejects the background in our analysis. The advantage in using the pp dataset is that the production of η mesons is almost a factor of 10 higher than in the pd fusion to 3He. As we plan to measure the branching ratios of very rare processes, high statistics is needed. A summary of the recent activity on the study of light mesons with WASA-at-COSY here is given.

Study of light mesons with WASA-at-COSY

Directory of Open Access Journals (Sweden)

Prencipe Elisabetta

2014-06-01

Full Text Available The WASA detector, operating at the COSY facility in Jülich (Germany has been collecting data since 2007. The experiment allows to perform studies of light mesons, such as π0, η and ω rare decay processes, in order to perform precise measurements of branching ratios, determine Dalitz plot parameters, test symmetry and symmetry breaking, and evaluate transition form factors. In the experiments a proton or deuteron beam impinged on a pellet target of hydrogen or deuterium, which allows the reactions proton-proton (pp or proton-deuteron (pd. A high-statistics sample of η mesons has been collected: in the reaction pd →3He η, 3×107η mesons were tagged at a beam energy of 1.0 GeV, while 5×108η mesons were produced in the reaction pp → ppη at 1.4 GeV. This corresponds to the production of 10 η/s and 100 η/s, respectively, for the two reaction processes. In the pp dataset a higher background level is found compared to the pd data set. In both cases, we identify the η mesons by means of the missing mass derived from the recoil particles. A kinematic fit largely rejects the background in our analysis. The advantage in using the pp dataset is that the production of η mesons is almost a factor of 10 higher than in the pd fusion to 3He. As we plan to measure the branching ratios of very rare processes, high statistics is needed. A summary of the recent activity on the study of light mesons with WASA-at-COSY here is given.

Interference in Exclusive Vector Meson Production in Heavy-Ion Collisions

International Nuclear Information System (INIS)

Klein, Spencer R.; Nystrand, Joakim

2000-01-01

Vector mesons are produced copiously in peripheral relativistic heavy-ion collisions. Virtual photons from one ion can fluctuate into quark-antiquark pairs and scatter from the second ion, emerging as vector mesons. The emitter and target are indistinguishable, so emission from the two ions will interfere. Vector mesons have negative parity so the interference is destructive, reducing the production of mesons with small transverse momentum. The mesons are short lived, and decay before emission from the two ions can overlap. However, the decay-product wave functions overlap and interfere since they are produced in an entangled state, providing an example of the Einstein-Podolsky-Rosen paradox. (c) 2000 The American Physical Society

The search for scalar mesons

International Nuclear Information System (INIS)

Pennington, M.R.

1988-09-01

The search of I = 0 0 ++ mesons is described. We highlight the crucial role played by the states in the 1 GeV region. An analysis program that with unimpeachable data would produce definitive results on these is outlined and shown with present data to provide prima facie evidence for dynamics beyond that of the quark model. We briefly speculate on the current status of the lowest mass scalar mesons and discuss how experiment can resolve the unanswered issues. 30 refs., 6 figs., 1 tab

Meson spectral functions at finite temperature

International Nuclear Information System (INIS)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S.

2001-10-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T c . The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64) 3 x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature. (orig.)

Meson spectral functions at finite temperature

International Nuclear Information System (INIS)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S.

2002-01-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T c . The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64) 3 x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature

Meson spectral functions at finite temperature

Energy Technology Data Exchange (ETDEWEB)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S

2002-03-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T{sub c}. The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64){sup 3} x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature.

Meson spectral functions at finite temperature

Energy Technology Data Exchange (ETDEWEB)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S. [Bielefeld Univ. (Germany). Fakultaet fuer Physik

2001-10-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T{sub c}. The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64){sup 3} x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature. (orig.)

A unified model of K- and π-mesons

International Nuclear Information System (INIS)

Skyrme, T.H.R.

1994-01-01

On the foundation of an antecedent non-linear meson field theory it is suggested that the π-meson field may be described in terms of collective motions of the K-meson fields. A particular model of the K-nucleon interaction is considered whose collective π-modes have symmetrical PV coupling with the nucleon system; parity is conserved to a great extent for the π-nucleon system in the absence of strange particles. The direct K-nucleon interactions do not conserve parity; their sign and symmetry are qualitatively acceptable. The masses and coupling constants of the meson fields are determinate in terms of one universal coupling constant and a cut-off. The structure of this model suggests a natural way for the introduction of the 'spurion', describing weak interactions that violate strangeness. (author). 6 refs

Measurement of elastic electroproduction of $\\phi$ mesons at HERA

CERN Document Server

Adloff, C.; Andrieu, B.; Arkadov, V.; Astvatsatourov, A.; Ayyaz, I.; Babaev, A.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Bate, P.; Beglarian, A.; Behnke, O.; Beier, C.; Belousov, A.; Benisch, T.; Berger, Christoph; Bernardi, G.; Berndt, T.; Bizot, J.C.; Borras, K.; Boudry, V.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruckner, W.; Bruel, P.; Bruncko, D.; Burger, J.; Busser, F.W.; Bunyatyan, A.; Burkhardt, H.; Burrage, A.; Buschhorn, G.; Campbell, A.J.; Cao, Jun; Carli, T.; Caron, S.; Chabert, E.; Clarke, D.; Clerbaux, B.; Collard, C.; Contreras, J.G.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; David, M.; Davidsson, M.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dixon, P.; Dodonov, V.; Dowell, J.D.; Droutskoi, A.; Duprel, C.; Eckerlin, Guenter; Eckstein, D.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Ferron, S.; Fleischer, M.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Foster, J.M.; Franke, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Ghazarian, S.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goodwin, C.; Grab, C.; Grassler, H.; Greenshaw, T.; Grindhammer, Guenter; Hadig, T.; Haidt, D.; Hajduk, L.; Haynes, W.J.; Heinemann, B.; Heinzelmann, G.; Henderson, R.C.W.; Hengstmann, S.; Henschel, H.; Heremans, R.; Herrera, G.; Herynek, I.; Hilgers, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Hoprich, W.; Horisberger, R.; Hurling, S.; Ibbotson, M.; Issever, C.; Jacquet, M.; Jaffre, M.; Janauschek, L.; Jansen, D.M.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jones, M.A.S.; Jung, H.; Kastli, H.K.; Kant, D.; Kapichine, M.; Karlsson, M.; Karschnick, O.; Kaufmann, O.; Kausch, M.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kermiche, S.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Kotelnikov, S.K.; Krasny, M.W.; Krehbiel, H.; Kroseberg, J.; Krucker, D.; Kruger, K.; Kupper, A.; Kuhr, T.; Kurca, T.; Kutuev, R.; Lachnit, W.; Lahmann, R.; Lamb, D.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindstrom, M.; Lobodzinska, E.; Lobodzinski, B.; Loktionova, N.; Lubimov, V.; Luders, S.; Luke, D.; Lytkin, L.; Magnussen, N.; Mahlke-Kruger, H.; Malden, N.; Malinovski, E.; Malinovski, I.; Maracek, R.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Mehta, A.; Meier, K.; Merkel, P.; Metlica, F.; Meyer, H.; Meyer, J.; Meyer, P.O.; Mikocki, S.; Milstead, D.; Mkrtchyan, T.; Mohr, R.; Mohrdieck, S.; Mondragon, M.N.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Nellen, G.; Newman, Paul R.; Nicholls, T.C.; Niebergall, F.; Niebuhr, C.; Nix, O.; Nowak, G.; Nunnemann, T.; Olsson, J.E.; Ozerov, D.; Panassik, V.; Pascaud, C.; Patel, G.D.; Perez, E.; Phillips, J.P.; Pitzl, D.; Poschl, R.; Potachnikova, I.; Povh, B.; Rabbertz, K.; Radel, G.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Reyna, D.; Riess, S.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Royon, C.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schoeffel, L.; Schoning, A.; Schorner, T.; Schroder, V.; Schultz-Coulon, H.C.; Sedlak, K.; Sefkow, F.; Chekelian, V.I.; Sheviakov, I.; Shtarkov, L.N.; Siegmon, G.; Sievers, P.; Sirois, Y.; Sloan, T.; Smirnov, P.; Solochenko, V.; Solovev, Y.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Steinhart, J.; Stella, B.; Stellberger, A.; Stiewe, J.; Straumann, U.; Struczinski, W.; Swart, M.; Tasevsky, M.; Tchernyshov, V.; Tchetchelnitski, S.; Thompson, Graham; Thompson, P.D.; Tobien, N.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Udluft, S.; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vazdik, Y.; von Dombrowski, S.; Wacker, K.; Wallny, R.; Walter, T.; Waugh, B.; Weber, G.; Weber, M.; Wegener, D.; Wegner, A.; Wengler, T.; Werner, M.; White, G.; Wiesand, S.; Wilksen, T.; Winde, M.; Winter, G.G.; Wissing, C.; Wobisch, M.; Wollatz, H.; Wunsch, E.; Wyatt, A.C.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; Zsembery, J.

2000-01-01

The elastic electroproduction of phi mesons is studied at HERA with the H1 detector for photon virtualities 1 < Q^2 < 15 GeV^2 and hadronic centre of mass energies 40 < W < 130 GeV. The Q^2 and t dependences of the cross section are extracted (t being the square of the four-momentum transfer to the target proton). When plotted as function of (Q^2 + M_V^2) and scaled by the appropriate SU(5) quark charge factor, the phi meson cross section agrees within errors with the cross sections of the vector mesons V = rho, omega and J/psi. A detailed analysis is performed of the phi meson polarisation state and the ratio of the production cross sections for longitudinally and transversely polarised phi mesons is determined. A small but significant violation of s-channel helicity conservation (SCHC) is observed.

Photoproduction of scalar mesons at medium energies

Energy Technology Data Exchange (ETDEWEB)

Da Silva, M. L. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-090, Pelotas, RS (Brazil); Machado, M. V. [High Energy Physics Phenomenology Group, GFPAE IF-UFRGS, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2013-03-25

In this work we will focus on photoproduction of mesons states a{sub 0}(980), f{sub 0}(1500) and f{sub 0}(1710). The f{sub 0}(1500) and f{sub 0}(1710) mesons will be considered in distinct mixing possibilities and assuming that a{sub 0}(980) is member of the ground-state nonet. The theoretical formalism is the Regge approach with reggeized {rho} and {omega} exchange. The differential and integrated total cross section are computed for the cases of the mesons a{sub 0}(980), f{sub 0}(1500) and f{sub 0}(1710) focusing the GlueX energy regime with photon energy E = 9 GeV.

Semileptonic B-meson decays in SU(3)

International Nuclear Information System (INIS)

Li Zuohong; Hou Yunzhi

1994-01-01

Based on the SU(3) approximate symmetry in the strong interaction three-body and four-body semileptonic B-meson decays are analyzed. Relations between decay rates are derived. Some of these relations may provide information on the nature of various competing dynamical effects that can occur in semileptonic B-meson decays

Decays of mesons with charm quarks on the lattice

International Nuclear Information System (INIS)

Ali Khan, A.; Braun, V.; Burch, T.; Goeckeler, M.; Schaefer, A.; Schierholz, G.

2007-10-01

We investigate mesons containing charm quarks on fine lattices with a -1 ∝ 5 GeV. The quenched approximation is employed using theWilson gauge action at β = 6.6 and nonperturbatively O(a) improvedWilson quarks. We present results for decay constants using various interpolating fields and give preliminary results for form factors of semileptonic decays of D s mesons to light pseudoscalar mesons. (orig.)

Method of taking into account the meson and quark-gluon degrees of freedom in hadron-hadron interactions at low and intermediate energies. Application to NN scattering

International Nuclear Information System (INIS)

Safronov, A.N.

1983-01-01

A system of nonsingular integral equations is formulated for calculation of the partial-wave amplitudes of hadron-hadron scattering in the region of low and intermediate energies with allowance for the meson and quark-gluon degrees of freedom. The quark-gluon degrees of freedom are taken into account in the framework of the model of composite quark bags, and the meson degrees of freedom by the methods of relativistic quantum field theory. It is shown that inclusion of the quark-gluon degrees of freedom leads to suppression of meson exchange effects, for the most part exchanges of heavy mesons (rho,ω). The method is applied to the calculation of the 3 S 1 , 1 S 0 , 3 P 0 , 3 P 1 , and 1 P 1 phase shifts of nucleon-nucleon scattering in the range of incident-nucleon energies T = 0--1050 MeV, as well as the S-wave scattering lengths and effective ranges

Electroproduction of pseudoscalar mesons at large transverse momenta

Energy Technology Data Exchange (ETDEWEB)

Domokos, G.; Kovesi-Domokos, S.; Yunn, B. C.

1973-07-15

Inclusive electroproduction of spinless (pseudoscalar) mesons at large transverse momenta is studied in the framework of local scale invariance. Scaling laws are established for the structure iunctions and approximate analytic expressions are derived for the scaling functions. It is predicted that the cross section decreases essentially according to a power law as a function of the transverse momentum of the observed meson, similarly to hadronic cross sections. The production rate of heavy mesons is found to rise slowly with the laboratory energy of the virtual photon. (auth)

Meson-mass generation by instantons, 2

Energy Technology Data Exchange (ETDEWEB)

Saito, T [Kyoto Prefectural Univ. of Medicine (Japan); Shigemoto, K

1979-05-01

In a previous work we discussed how pseudo-scalar mesons and scalar mesons acquire their masses by instantons in the colored gauge field. We considered there the two-flavor model with chiral U(2) x U(2) symmetry. In the present paper the same problem is discussed, including the chiral flavor U(3) x U(3) symmetry. An importance of non-local effects due to instantons is emphasized.

THE ETA-MESON PHOTOPRODUCTION ON PROTON

Czech Academy of Sciences Publication Activity Database

Donoval, Jan; Bydžovský, Petr

2011-01-01

Roč. 26, 3-4 (2011), s. 645-646 ISSN 0217-751X. [11th International Workshop on Meson Production , Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/08/0984 Institutional research plan: CEZ:AV0Z10480505 Keywords : Eta-meson photoproduction * form factors * nucleon resonances Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.053, year: 2011

The interpretation of the iota meson

International Nuclear Information System (INIS)

Frank, M.

1985-01-01

The authors analyze the iota (1440) meson in a non-relativistic quark model. The authors review the experimental data, then attempt to incorporate it in the mass spectrum and radiative decays of the low-lying pseudoscalar and vector mesons. Correlating these results with production decay rates from J/psi and the radiative decays of iota, the authors conclude that the iota has to be interpreted as having a strong gluonium component

Excited charmed mesons

International Nuclear Information System (INIS)

Butler, J.N.; Shukla, S.

1995-05-01

The experimental status of excited charmed mesons is reviewed and is compared to theoretical expectations. Six states have been observed and their properties are consistent with those predicted for excited charmed states with orbital angular momentum equal to one

Chiral power counting and pp → ppπ0 near threshold

International Nuclear Information System (INIS)

Van Kolck, U.; Miller, G.A.

1995-01-01

The pp → ppπ 0 reaction is studied near threshold using power counting arguments based on chiral perturbation theory with an explicit Δ degree of freedom. Important contributions include the so-called impulse term, rescattering via the Δ and rescattering via the (off-shell) seagull term responsible for s-wave pion-nucleon scattering. These contributions largely cancel so that their sum greatly underpredicts the total cross-section. Other mechanisms are also discussed. The inclusion of the previously proposed σ meson exchange mechanism is not sufficient to resolve the discrepancy with experiment

A unitarized meson model including color Coulomb interaction

International Nuclear Information System (INIS)

Metzger, Kees.

1990-01-01

Ch. 1 gives a general introduction into the problem field of the thesis. It discusses in how far the internal structure of mesons is understood theoretically and which models exist. It discusses from a phenomenological point of view the problem of confinement indicates how quark models of mesons may provide insight in this phenomenon. In ch. 2 the formal theory of scattering in a system with confinement is given. It is shown how a coupled channel (CC) description and the work of other authors fit into this general framework. Explicit examples and arguments are given to support the CC treatment of such a system. In ch. 3 the full coupled-channel model as is employed in this thesis is presented. On the basis of arguments from the former chapters and the observed regularities in the experimental data, the choices underlying the model are supported. In this model confinement is described with a mass-dependent harmonic-oscillator potential and the presence of open (meson-meson) channels plays an essential role. In ch. 4 the unitarized model is applied to light scalar meson resonances. In this regime the contribution of the open channels is considerable. It is demonstrated that the model parameters as used for the description of the pseudo-scalar and vector mesons, unchanged can be used for the description of these mesons. Ch. 5 treats the color-Coulomb interaction. There the effect of the Coulomb interaction is studied in simple models without decay. The results of incorporating the color-Coulomb interaction into the full CC model are given in ch.6. Ch. 7 discusses the results of the previous chapters and the present status of the model. (author). 182 refs.; 16 figs.; 33 tabs

J/Ψ decays, quark-gluon mixing in light mesons and glueball interpretation of L(1440), Θ(1720) and S*(980)-mesons

International Nuclear Information System (INIS)

Eremyan, Sh.S.; Nazaryan, A.Eh.

1987-01-01

The mixing angles for pseudoscalar, tensor and scalar meson multiplets are obtained in assumption on existence of a glueball component. The results are shown to be independent on the kind of the mixing matrix. It turned out that L(1440), Θ(1720) and S*(980) mesons are quite real candidates for glueballs. All the available experimental data on two-particle decays of 0 - , 2 + and 0 + -mesons are described and predictions for a large of such decays are given. 13 refs.; 6 figs.; 9 tabs

Studies of Excited $D$ mesons in $B$ meson decays

CERN Document Server

AUTHOR|(CDS)2082679

This thesis documents the studies of several three-body B + meson decays, each with a charged charmed meson in the final state. All analyses presented use a data sample recorded by the LHCb detector in 2011 and 2012, corresponding to an integrated luminosity of 3.0 $fb^{-1}$ of $pp$ collision data. The $B^{+} \\to D^{-}K^{+}\\pi^{+}$ and $B^{+} \\to D^{+}K^{+}\\pi^{-}$ decay modes are observed for the first time. The branching fraction of the favoured $B^{+} \\to D^{-}K^{+}\\pi^{+}$ decay mode is measured relative to the topologically similar $B^{+} \\to D^{-}\\pi^{+}\\pi^{+}$ decay and the $B^{+} \\to D^{-}K^{+}\\pi^{+}$ final state is used as a normalisation channel for the suppressed $B^{+} \\to D^{+}K^{+}\\pi^{-}$ decay branching fraction measurement. Searches are performed for the quasi-two-body decays $B^{+} \\to D^{+}K^{*}(892)^{0}$ and $B^{+} \\to D_{2}^{*}(2460)^{0}K^{+}$, using the sample of $B^{+} \\to D^{+}K^{+}\\pi^{-}$ candidate decays. No significant signals are observed for either decay mode and upper limits a...

Meson-Meson molecules and compact four-quark states

International Nuclear Information System (INIS)

Vijande, J.; Valcarce, A.

2010-01-01

The physics of charm has become one of the best laboratories exposing the limitations of the naive constituent quark model and also giving hints into a more mature description of meson spectroscopy, beyond the simple quark-antiquark configurations. In this talk we review some recent studies of multiquark components in the charm sector and discuss in particular exotic and non-exotic four-quark systems.

Self-consistent descriptions of vector mesons in hot matter reexamined

International Nuclear Information System (INIS)

Riek, Felix; Knoll, Joern

2010-01-01

Technical concepts are presented that improve the self-consistent treatment of vector mesons in a hot and dense medium. First applications concern an interacting gas of pions and ρ mesons. As an extension of earlier studies, we thereby include random-phase-approximation-type vertex corrections and further use dispersion relations to calculate the real part of the vector-meson self-energy. An improved projection method preserves the four transversality of the vector-meson polarization tensor throughout the self-consistent calculations, thereby keeping the scheme void of kinematical singularities.

Experimental evidence for hadroproduction of exotic mesons

International Nuclear Information System (INIS)

G. S. Adams; T. Adams; Z. Bar-Yam; J. M. Bishop; V. A. Bodyagin; B. B. Brabson; D. S. Brown; N. M. Cason; S. U. Chung; R. R. Crittenden; J. P. Cummings; K. Danyo; S. Denisov; V. Dorofeev; J. P. Dowd; A. R. Dzierba; P. Eugenio; J. Gunter; R. W. Hackenburg; M. Hayek; E. I. Ivanov; I. Kachaev; W. Kern; E. King; O. L. Kodolova; V. L. Korotkikh; M. A. Kostin; J. Kuhn; R. Lindenbusch; V. Lipaev; J. M. LoSecco; J. J. Manak; J. Napolitano; M. Nozar; C. Olchanski; A. I. Ostrovidov; T. K. Pedlar; A. Popov; D. R. Rust; D. Ryabchikov; A. H. Sanjari; L. I. Sarycheva; E. Scott; K. K. Seth; N. Shenhav; W. D. Shephard; N. B. Sinev; J. A. Smith; P. T. Smith; D. L. Stienike; T. Sulanke; S. A. Taegar; S. Teige; D. R. Thompson; I. N. Vardanyan; D. P. Weygand; D. White; H. J. Willutzki; J. Wise; M. Witkowski; A. A. Yershov; D. Zhao

2001-01-01

New measurements of peripheral meson production are presented. The data confirm the existence of exotic mesons at 1.4 and 1.6 GeV/c2. The latter state dominates the eta'pi- decay spectrum. The data on eta pi+pi-pi- decay show large strength in several exotic (Jpc = 1- +) waves as well

QED effects in the pseudoscalar meson sector

Energy Technology Data Exchange (ETDEWEB)

Horsley, R. [School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD (United Kingdom); Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo, 650-0047 (Japan); Perlt, H. [Institut für Theoretische Physik, Universität Leipzig, Brüderstrasse 16, Leipzig, 04109 (Germany); Pleiter, D. [Jülich Supercomputer Centre, Forschungszentrum Jülich, Jülich, 52425 (Germany); Institut für Theoretische Physik, Universität Regensburg, Regensburg, 93040 (Germany); Rakow, P.E.L. [Theoretical Physics Division, Department of Mathematical Sciences, University of Liverpool, Peach Street , Liverpool, L69 3BX (United Kingdom); Schierholz, G. [Deutsches Elektronen-Synchrotron DESY, Hamburg, 22603 (Germany); Schiller, A. [Institut für Theoretische Physik, Universität Leipzig, Brüderstrasse 16, Leipzig, 04109 (Germany); Stokes, R. [CSSM, Department of Physics, University of Adelaide, Adelaide, SA, 5005 (Australia); Stüben, H. [Regionales Rechenzentrum, Universität Hamburg, Hamburg, 20146 (Germany); Young, R.D.; Zanotti, J.M. [CSSM, Department of Physics, University of Adelaide, Adelaide, SA, 5005 (Australia); Collaboration: the QCDSF and UKQCD collaboration

2016-04-15

In this paper we present results on the pseudoscalar meson masses from a fully dynamical simulation of QCD+QED, concentrating particularly on violations of isospin symmetry. We calculate the π{sup +}–π{sup 0} splitting and also look at other isospin violating mass differences. We have presented results for these isospin splittings in http://arxiv.org/abs/1508.06401. In this paper we give more details of the techniques employed, discussing in particular the question of how much of the symmetry violation is due to QCD, arising from the different masses of the u and d quarks, and how much is due to QED, arising from the different charges of the quarks. This decomposition is not unique, it depends on the renormalisation scheme and scale. We suggest a renormalisation scheme in which Dashen’s theorem for neutral mesons holds, so that the electromagnetic self-energies of the neutral mesons are zero, and discuss how the self-energies change when we transform to a scheme such as (MS)-bar , in which Dashen’s theorem for neutral mesons is violated.

Oscillations of neutral B mesons systems

CERN Document Server

Boucrot, J.

1999-01-01

The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the $\\bd$ meson oscillation frequency is $\\dmd = 0.471 \\pm 0.016 \\ps$ and the lower limit on the $\\bs$ oscillation frequency is

Hybrid mesons with auxiliary fields

International Nuclear Information System (INIS)

Buisseret, F.; Mathieu, V.

2006-01-01

Hybrid mesons are exotic mesons in which the color field is not in the ground state. Their understanding deserves interest from a theoretical point of view, because it is intimately related to nonperturbative aspects of QCD. Moreover, it seems that some recently detected particles, such as the π 1 (1600) and the Y(4260), are serious hybrid candidates. In this work, we investigate the description of such exotic hadrons by applying the auxiliary fields technique (also known as the einbein field method) to the widely used spinless Salpeter Hamiltonian with appropriate linear confinement. Instead of the usual numerical resolution, this technique allows to find simplified analytical mass spectra and wave functions of the Hamiltonian, which still lead to reliable qualitative predictions. We analyse and compare two different descriptions of hybrid mesons, namely a two-body q system with an excited flux tube, or a three-body qg system. We also compute the masses of the 1 -+ hybrids. Our results are shown to be in satisfactory agreement with lattice QCD and other effective models. (orig.)

Anomalous length of electron bunches as an instability threshold

International Nuclear Information System (INIS)

Messerschmid, E.; Month, M.

1976-01-01

A mechanism for the anomalous length of electron bunches, based on the existence of a ''fast'' longitudinal instability, is proposed. The equilibrium length is obtained by requiring that the growth rate be sufficiently larger than the rate of synchrotron oscillations. The theory is used to describe the bunch length data for SPEAR at 1.5 GeV. The low voltage and/or high current regime is dominated by a set of ''low'' frequency, low Q resonators [e.g., f = 320 MHz, Δf(fwhm) = 130 MHz]. To fit the observations in the high voltage and/or low current regime, a high frequency, low Q impedance is required (e.g., f = 3.8 GHz, Δf = 1.0 GHz). The mechanism is mediated by the resistive component of the impedance. Thus, there is qualitative agreement with the observed distortion of the bunch tail. This is in contrast to the predictions of the potential well models based on a reactive impedance source. These latter theories yield large distortions of the head of the bunch. The calculated power dissipated in the assumed sources by the given electron bunch is not inconsistent with estimates made for SPEAR

On wave functions of mesons involving the s-, c- and b-quarks

International Nuclear Information System (INIS)

Zhitnitskij, A.R.; Zhitnitskij, I.R.; Chernyak, V.L.

1983-01-01

The wave function components of pseudoscalar and vestor mesons which are antisymmertric with respect to permutation of the quark momenta are studied. The results are as follows: elt xsub(s)-xsub(u) > sub(K) approximately equal to 0.11 for the K meson, sub(K*) approximately equal to 0.15-C.20 for the K* meson, being a mean fraction of the longitudinal momentum transferred by the s(u) quark. The following estimates are obtained: / approximately equal to 0.20-0.25; / approximately equal to 0.8x10 -2 . The asymptotics of the K 0 -meson form factor and the etasub(c) → KK* decay width are found. Properties of the wave functions of mesons which contain a light and a heavy quark (D, B, ...) are considered. For the B 0 meson approximately equal to 0.10 is found. Arguments are given supporting nonenhancement of the amplitudes of the processes involving D mesons compared to similar K-meson amplitudes. A simple way is suggested to determine the asymptotic form of various wave functions

About direct CP violation in the system of K0 mesons

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

2012-01-01

This work is devoted to computation of the parameter of direct CP violation by the weak interactions in the system of K 0 mesons at K 1 0 -, K 2 0 -meson mixings and oscillations via K S -, K L -meson states

Mesonic atom production in high-energy nuclear collisions

International Nuclear Information System (INIS)

Wakai, M.; Bando, H.; Sano, M.

1987-08-01

The production probability of π-mesonic atom in high-energy nuclear collisions is estimated by a coalescence model. The production cross section is calculated for p + Ne and Ne + Ne systems at 2.1 GeV/A and 5.0 GeV/A beam energy. It is shown that nuclear fragments with larger charge numbers have the advantage in the formation of π-mesonic atoms. The cross section is proportional to Z 3 and of the order of magnitude of 1 ∼ 10 μb in all the above cases. The production cross sections of K-mesonic atoms are also estimated. (author)

Light meson decays in CLAS and CLAS12

Energy Technology Data Exchange (ETDEWEB)

Kunkel, Michael [Forschungszentrum Juelich (Germany); Collaboration: CLAS Collaboration

2016-07-01

Photoproduction experiments with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Facility produce data sets with competitive statistics of light mesons. With these data sets, measurements of transition form factors for η, ω, and η' mesons via conversion decays can be performed using the invariant mass distribution of the final state dileptons. Tests of fundamental symmetries and information on the light quark mass difference can be performed using a Dalitz plot analysis of the meson decay. An overview of preliminary results, from existing CLAS data, and future prospects within the newly upgraded CLAS12 apparatus are given.

On the mesonic-exchange currents in the photomesic reactions

International Nuclear Information System (INIS)

Lazard, C.; Maric, Z.; Zivanovic, D.

1979-02-01

The γd→π 0 d reaction is analysed in the framework of the relativistic many-body theory with mesonic degrees of freedom explicitly present. It is shown that the mesonic correlations can be grouped into transition operators containing vertices of some elementary reactions between photon, nucleons and pions. The wave function corrections due to meson exchange currents are included in the transition operators and the S-matrix is obtained with the non relativistic deuteron wave function

Finite temperature QCD sum rule and the ρ-meson

International Nuclear Information System (INIS)

Liu Jueping; Jin Yaping

1995-01-01

The contributions from the three-gluon condensates to the finite temperature QCD sum rule for the ρ-meson are calculated, and then the dependence of the properties of the ρ-meson upon temperature is investigated in a string model of condensates. The results show that the parameters characterizing the properties of the ρ-meson change noticeably when the temperature closes to the critical temperature of the condensates, and if the critical temperatures of condensates are the same

Scalar meson field and many-body forces. Chapter 23

International Nuclear Information System (INIS)

Nyman, E.M.

1979-01-01

In applications of field theory to the theory of the nuclear forces, one has frequently assumed that there is a scalar meson. It will then be responsible for most of the medium-range attraction between the nucleons. According to current ideas, however, it is possible to account for the medium-range attraction without an elementary sigma meson. This approach requires a careful treatment of the exchange of interacting pairs of π mesons, such as to include those ππ interactions which are responsible for the formation and decay of the sigma meson. Recently, the scalar field in the nuclear many-body problem has begun to receive more attention. There are two reasons for this change of philosophy. One reason is the discovery of neutron stars. In neutron stars, the nucleon number density can be much higher than in nuclei. One therefore wants to derive the equation of state from a relativistic many-body theory. This forces one to deal explicitly with a set of mesons, such that in the non-relativistic limit one recovers the one-boson-exchange potential. (Auth.)

Scattering of vector mesons off nucleons

International Nuclear Information System (INIS)

Lutz, M.F.M.; Friman, B.; Wolf, G.

2001-12-01

We construct a relativistic and unitary approach to 'high' energy pion- and photon-nucleon reactions taking the πN, πΔ, ρN, ωN, ηN, K Λ, KΣ final states into account. Our scheme dynamically generates the s- and d-wave nucleon resonances N(1535), N(1650) and N(1520) and isobar resonances Δ(1620) and δ(1700) in terms of quasi-local interaction vertices. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local 4-point interaction vertices to the corresponding vertices involving the ρ and ω fields. We obtain a satisfactory description of the elastic and inelastic pion- and photon-nucleon scattering data in the channels considered. The resulting s-wave ρ- and ω-nucleon scattering amplitudes are presented. Using these amplitudes we compute the leading density modification of the ρ and ω mass distributions in nuclear matter. We find a repulsive mass shift for the ω meson at small nuclear density but predict considerable strength in resonance-hole like ω-meson modes. Compared to previous calculations our result for the ρ-meson spectral function shows a significantly smaller in-medium effect. This reflects a not too large coupling strength of the N(1520) resonance to the ρN channel. (orig.)

Near threshold fatigue testing

Science.gov (United States)

Freeman, D. C.; Strum, M. J.

1993-01-01

Measurement of the near-threshold fatigue crack growth rate (FCGR) behavior provides a basis for the design and evaluation of components subjected to high cycle fatigue. Typically, the near-threshold fatigue regime describes crack growth rates below approximately 10(exp -5) mm/cycle (4 x 10(exp -7) inch/cycle). One such evaluation was recently performed for the binary alloy U-6Nb. The procedures developed for this evaluation are described in detail to provide a general test method for near-threshold FCGR testing. In particular, techniques for high-resolution measurements of crack length performed in-situ through a direct current, potential drop (DCPD) apparatus, and a method which eliminates crack closure effects through the use of loading cycles with constant maximum stress intensity are described.

Glueball-meson mixing

Energy Technology Data Exchange (ETDEWEB)

Vento, Vicente [Consejo Superior de Investigaciones Cientificas, Departamento de Fisica Teorica y Instituto de Fisica Corpuscular, Universidad de Valencia, Burjassot (Spain)

2016-01-15

Calculations in unquenched QCD for the scalar glueball spectrum have confirmed previous results of Gluodynamics finding a glueball at ∝1750 MeV. I analyze the implications of this discovery from the point of view of glueball-meson mixing in light of the experimental scalar spectrum. (orig.)

δ meson effects in the Nolen-Schiffer anomaly

International Nuclear Information System (INIS)

Menezes, D.P.; Avancini, S.S.; Vasconcellos, C.Z.; Razeira, M.

2009-01-01

In this work we revisit the Okamoto-Nolen-Schiffer (ONS) anomaly in the context of four parametrizations of effective hadronic models, two of them with constant couplings between the nucleons and the mesons and two with density-dependent couplings. A Thomas-Fermi approximation is performed and the effects of the isovector-scalar virtual δ (a 0 (980)) mesons are investigated since they influence directly the proton and neutron effective masses in opposite ways. The ρ-ω mixing term is claimed to be important in the explanation of the ONS anomaly and is added in our calculations. We have concluded that as far as the ρ-ω mixing term is included, Δ M(Z, N) is clearly larger in models with δ than in models where this meson is not considered, which is not always the case if the coupling is discarded. None of the models is good enough to describe all experimental data, but the models that better describe the experimental values include the δ mesons. (orig.)

Meson masses in electromagnetic fields with Wilson fermions

Science.gov (United States)

Bali, G. S.; Brandt, B. B.; Endrődi, G.; Gläßle, B.

2018-02-01

We determine the light meson spectrum in QCD in the presence of background magnetic fields using quenched Wilson fermions. Our continuum extrapolated results indicate a monotonous reduction of the connected neutral pion mass as the magnetic field grows. The vector meson mass is found to remain nonzero, a finding relevant for the conjectured ρ -meson condensation at strong magnetic fields. The continuum extrapolation was facilitated by adding a novel magnetic field-dependent improvement term to the additive quark mass renormalization. Without this term, sizable lattice artifacts that would deceptively indicate an unphysical rise of the connected neutral pion mass for strong magnetic fields are present. We also investigate the impact of these lattice artifacts on further observables like magnetic polarizabilities and discuss the magnetic field-induced mixing between ρ -mesons and pions. We also derive Ward-Takashi identities for QCD +QED both in the continuum formulation and for (order a -improved) Wilson fermions.

Vector meson decays in the chiral bag model

International Nuclear Information System (INIS)

Maxwell, O.V.; Jennings, B.K.

1985-01-01

Vector meson decays are examined in a model where a confined quark and antiquark annihilate, producing a pair of elementary pseudoscalar mesons. Two versions of the pseudoscalar meson-quark interaction are employed, one where the coupling is restricted to the bag surface and one where it extends throughout the bag volume. Energy conservation is ensured in the model through insertion of exponential factors containing the bag energy at each interaction vertex. To guarantee momentum conservation, a wave-packet description is utilized in which the decay widths are normalized by a factor involving the overlap of the initial bag state with the confined qanti q state of zero momentum. With either interaction, the model yields a value for the p-width that exceeds the empirical width by a factor two. For the Ksup(*) and PHI mesons, the computed widths depend strongly on the interaction employed. Implications of these results for chiral bag models are discussed. (orig.)

Skyrmions and vector mesons: a symmetric approach

International Nuclear Information System (INIS)

Caldi, D.G.

1984-01-01

We propose an extension of the effective, low-energy chiral Lagrangian known as the Skyrme model, to one formulated by a non-linear sigma model generalized to include vector mesons in a symmetric way. The model is based on chiral SU(6) x SU(6) symmetry spontaneously broken to static SU(6). The rho and other vector mesons are dormant Goldstone bosons since they are in the same SU(6) multiplet as the pion and other pseudoscalars. Hence the manifold of our generalized non-linear sigma model is the coset space (SU(6) x SU(6))/Su(6). Relativistic effects, via a spin-dependent mass term, break the static SU(6) and give the vectors a mass. The model can then be fully relativistic and covariant. The lowest-lying Skyrmion in this model is the whole baryonic 56-plet, which splits into the octet and decuplet in the presence of relativistic SU(6)-breaking. Due to the built-in SU(6) and the presence of vector mesons, the model is expected to have better phenomenological results, as well as providing a conceptually more unified picture of mesons and baryons. 29 references

Hard production of exotic hybrid mesons

Energy Technology Data Exchange (ETDEWEB)

Anikin, I.; Teryaev, O.V. [Bogoliubov Lab. of Theoretical Physics, JINR, Dubna (Russian Federation); Pire, B.; Anikin, I. [Ecole Polytechnique, CPHT, 91 - Palaiseau (France); Szymanowski, I. [Soltan Institute for Nuclear Studies, Warsaw (Poland); Liege Univ. (Belgium); Anikin, I.; Wallon, S. [Paris-11 Univ., Lab. de Physique Theorique, 91 - Orsay (France)

2005-07-01

Exotic hybrid mesons H, with quantum numbers J{sup PC} = 1{sup -+} may be copiously produced in the hard exclusive processes {gamma}{sup *}(Q{sup 2}){gamma} {yields} H and {gamma}{sup *}(Q{sup 2})P(p) {yields} HP(p') because they have a leading twist distribution amplitude with a sizable coupling constant f{sub H}, which may be estimated through QCD sum rules. The reaction rates scale in the same way as the corresponding rates for usual mesons. (authors)

D-meson production by muons in the COMPASS experiment at CERN

Energy Technology Data Exchange (ETDEWEB)

Zvyagin, Alexander

2011-01-21

One of the physics goals of the COMPASS experiment at CERN was to measure the contribution of gluons to the nucleon spin. To achieve this, it was proposed to scatter polarized 160 GeV/c muons on a polarized deuteron target and to detect D mesons in the final state. The underlying process in this D meson production is supposed to be the Photon-Gluon Fusion (PGF), where a virtual photon emitted by the muon interacts with a gluon from the target nucleon, producing a charm-anticharm quark pair. Fragmentation of a charm (anticharm) quark leads with high probability to the creation of a D{sup 0} or D{sup *} meson, which COMPASS detects via the D{sup 0}{yields}K{pi} and D{sup *}{yields}D{sup 0}{pi}{yields}K{pi}{pi} decay modes. From the longitudinal cross section spin asymmetries of the D meson production and theoretical predictions for the PGF cross section, the gluon contribution to the nucleon spin has been measured by the COMPASS experiment. The results presented in the thesis are the following. Based on data from the year 2004 a total visible cross section of 1.8{+-}0.4 nb, for the D{sup *} meson production, has been measured, with the error being dominated by systematic effects. It is validated that the D mesons are indeed produced through the PGF process, by comparison of measured D meson kinematic distributions to the ones predicted by a theory (AROMA generator). A good agreement was found for the distribution shapes, which confirms that PGF plays a major role. However, a 20% difference was found in the number of produced D{sup 0} and D{sup 0} mesons (and for the D{sup *+} and D{sup *-} mesons as well) which is significantly larger than predicted by AROMA. Kinematic distributions of D{sup 0} and D{sup *} mesons were compared with the background and also with the nearby K{sup *}{sub 2}(1430){sup 0} resonance, using all longitudinal data taken in 2002-2006. The particle-antiparticle asymmetry has been studied as a function of several kinematic variables. The 20

Light meson decays from photon-induced reactions with CLAS

Energy Technology Data Exchange (ETDEWEB)

Kunkel, Michael C. [Forschungszentrum Juelich (Germany); Collaboration: CLAS-Collaboration

2015-07-01

Photo-production experiments with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Laboratory produce data sets with unprecedented statistics of light mesons. With these data sets, measurements of transition form factors for η, ω, and η' via conversion decays are performed using a line shape analysis on the invariant mass of the final state dileptons. Tests of fundamental symmetries and information on the light quark mass difference are performed using a Dalitz plot analysis of the meson decay. In addition, the data allows for a search for dark matter, such as the heavy photon via conversion decays of light mesons and physics beyond the Standard Model is searched for via invisible decays of η mesons. An overview of the first results and future prospects is given.

QCD sum rules for the decay amplitudes of pseudoscalar mesons

International Nuclear Information System (INIS)

Narison, S.

1981-07-01

Bounds on the π and K meson decay amplitudes are obtained to a good accuracy from QCD sum rules of the Laplace transform type. A relation between fsub(π) and the rho meson coupling to the photon is given. Using the heavy quarks q 2 =0 sum rule to two loops we find our best bounds: fsub(D) approximately < (101+-25) MeV and fsub(F) approximately < (147+-41.6) MeV to be compared to fsub(π) approximately 93.3 MeV. We also derive a relation between the D and F meson masses and the charm quark mass. Our results are extended to the beautiful B mesons. (author)

Mesons versus quasi-normal modes: undercooling and overheating

NARCIS (Netherlands)

Paredes Galan, A.; Peeters, K.; Zamaklar, m.

2008-01-01

In holographic models of gauge theories with matter, there generically exists a first order phase transition in which mesons dissociate. We perform a careful analysis of the meson and quasi-particle spectra in the overheated resp. undercooled regimes close to the junction of the two phases. We show

Electro- and chromomagnetism in the charm meson spectrum

International Nuclear Information System (INIS)

Fritzsch, H.

1977-01-01

How the D and F meson spectrum is influenced by the chromomagnetic and electomagnetic hyperfine interaction is discussed. In particular a relation between the hyperfine splitting of charmed mesons and the magnetic moments of the baryons is derived. M(Fsub(+)*)-M(Fsub(+)) approximately 100+-8 MeV. (Auth.)

Meson-Baryon Scattering Lengths from Mixed-Action Lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Will Detmold, William Detmold, Konstantinos Orginos, Aaron Torok, Silas R Beane, Thomas C Luu, Assumpta Parreno, Martin Savage, Andre Walker-Loud

2010-04-01

The $\\pi^+\\Sigma^+$, $\\pi^+\\Xi^0$ , $K^+p$, $K^+n$, and $K^0 \\Xi^0$ scattering lengths are calculated in mixed-action Lattice QCD with domain-wall valence quarks on the asqtad-improved coarse MILC configurations at four light-quark masses, and at two light-quark masses on the fine MILC configurations. Heavy Baryon Chiral Perturbation Theory with two and three flavors of light quarks is used to perform the chiral extrapolations. We find no convergence for the kaon-baryon processes in the three-flavor chiral expansion. Using the two-flavor chiral expansion, we find $a_{\\pi^+\\Sigma^+} = ?0.197 ± 0.017$ fm, and $a_{\\pi^+\\Xi^0} = ?0.098 0.017$ fm, where the comprehensive error includes statistical and systematic uncertainties.

Composite mesons in self-confining chiral solitons

International Nuclear Information System (INIS)

Tandy, P.C.; Frank, M.R.

1991-01-01

Most quark-meson models for formation of a baryon as a bag or soliton solution begin with elementary local meson fields including a classical scalar configuration that provides repulsion of valence quarks from the vacuum. This presentation explores aspects of the very different formation mechanism that operates in a model where chiral effective meson fields are composite objects generated from bilocal qq-bar fluctuation fields and the dynamical quark mass can be self-confining. The focus is on the dynamical self-energy for quarks and the related distributed vertex for quark meson coupling. Initial numerical work to explore the practical consequences of these features is presented in the context of a static mean-field soliton. The particular method employed to identify the energy functional at the mean field or Hartree level is to obtain the standard effective action from the Legendre transformation with the help of a chemical potential constraint for the baryon number. The purpose of this approach is two-fold. First, a possible future consideration of radiative corrections might be undertaken by systematically continuing with the loop expansion beyond the lowest level. A second, more practical reason, is that in the presence of a general space-time dependent dynamical self-energy for quarks there are wavefunction renormalisation effects and energy self-consistencies to be defined and maintained for the valence quark states and eigenvalues. Speculations are made on whether this point of view can motivate meson-nucleon relativistic field models containing intrinsic cutoffs for use in nuclear physics. 29 refs., 5 figs

Semileptonic decays of the Bc meson

International Nuclear Information System (INIS)

Barik, N.; Naimuddin, Sk.; Dash, P. C.; Kar, Susmita

2009-01-01

We study the semileptonic transitions B c →η c ,J/Ψ,D,D*,B,B*,B s ,B s * in the leading order in the framework of a relativistic independent quark model based on a confining potential in the equally mixed scalar-vector harmonic form. We compute relevant weak form factors as overlap integrals of the meson-wave functions obtained in the relativistic independent quark model in the whole accessible kinematical range. We predict that the semileptonic transitions of the B c meson are mostly dominated by two Cabibbo-Kobayashi-Maskawa (CKM)-favored modes, B c →B s (B s *)eν, contributing about 77% of the total decay width, and its decays to vector meson final states take place in the predominantly transverse mode. Our predicted values for the total decay rates, branching ratios, polarization ratios, the forward-backward asymmetry factor, etc., are broadly in agreement with other model predictions.

Κ-meson decays and parity violation

International Nuclear Information System (INIS)

Dalitz, R.H.

1989-01-01

Between 1948 and 1954 many Κ-meson decay modes were observed, including the tau, pion and xi positives, in emulsion experiments all with masses around 500 MeV. An attempt was made to rationalize the various names for the new particles being discovered. A period of experimental consolidation followed. An attempt was then made to determine the spin parity of the three-pion system from tau plus decay using matrix calculations. New stripped emulsion techniques now permitted a secondary-particle track to be followed to its endpoint. Stacked emulsions were flown in balloons to study Κ mesons and hyperons using cosmic radiation. Later similar work used the new particle accelerators, the Cosmotron and the Bevatron as sources. The author showed that the tau plus and theta plus were competing decay modes of the same Κ + meson, but this meant that parity conservation was violated. Later theoreticians T D Lee and C N Yang provided evidence for this surprising idea from their work on semileptonic weak interactions. (UK)

{phi} meson electroproduction at small Bjorken-x

Energy Technology Data Exchange (ETDEWEB)

Kroll, P. [Wuppertal Univ., Fachbereich Physik (Germany)

2005-07-01

It is reported on an analysis of {phi}-meson electroproduction at small Bjorken-x(x{sub B{sub j}}) within the handbag approach. The amplitudes can be factorized into generalized parton distribution (GPDs) and a partonic subprocess, electroproduction off gluons. Cross-sections and spin density matrix elements are evaluated for {phi}-meson electroproduction and found to be in fair agreement with recent HERA data. (author)

MESON AND DI-ELECTRON PRODUCTION WITH HADES

Czech Academy of Sciences Publication Activity Database

Frohlich, I.; Agakishiev, G.; Agodi, C.; Balanda, A.; Bellia, G.; Belver, D.; Belyaev, A.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Galatyuk, T.; Garzón, J.A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; Gonzalez-Diaz, D.; Grosse, E.; Guber, F.; Heilmann, M.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B.W.; Kotte, R.; Kozuch, A.; Krása, Antonín; Křížek, Filip; Krücken, R.; Kuhn, W.; Kugler, Andrej; Kurepin, A.; Lamas-Valverde, J.; Lang, S.; Lange, J.S.; Lapidus, K.; Lopes, L.; Maier, L.; Mangiarotti, A.; Marín, J.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Moriniére, E.; Mousa, J.; Muntz, C.; Naumann, L.; Novotny, R.; Otwinowski, J.; Pachmayer, Y.C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Cavalcanti, T.P.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Simon, R. S.; Sobolev, Yuri, G.; Spataro, S.; Spruck, B.; Strobele, H.; Stroth, J.; Sturm, C.; Sudol, M.; Tarantola, A.; Teilab, K.; Tlustý, Pavel; Traxler, M.; Trebacz, R.; Tsertos, H.; Veretenkin, I.; Wagner, Vladimír; Wen, H.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Yu.; Zhou, P.; Zumbruch, P.

2009-01-01

Roč. 24, 2-3 (2009), s. 317-326 ISSN 0217-751X. [Conference MESON 2008. Jagiellonian Univ, Cracow, 06.06.2008-10.06.2008] R&D Projects: GA AV ČR IAA100480803; GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : Mesons * di-electrons * resonances Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.941, year: 2009

Beautiful mesons from QCD spectral sum rules

International Nuclear Information System (INIS)

Narison, S.

1991-01-01

We discuss the beautiful meson from the point of view of the QCD spectral sum rules (QSSR). The bottom quark mass and the mixed light quark-gluon condensates are determined quite accurately. The decay constant f B is estimated and we present some arguments supporting this result. The decay constants and the masses of the other members of the beautiful meson family are predicted. (orig.)

Static-light meson masses from twisted mass lattice QCD

International Nuclear Information System (INIS)

Jansen, Karl; Michael, Chris; Shindler, Andrea; Wagner, Marc

2008-08-01

We compute the static-light meson spectrum using two-flavor Wilson twisted mass lattice QCD. We have considered five different values for the light quark mass corresponding to 300 MeV PS S mesons. (orig.)

Magnetic polarizabilities of light mesons in SU(3 lattice gauge theory

Directory of Open Access Journals (Sweden)

E.V. Luschevskaya

2015-09-01

Full Text Available We investigate the ground state energies of neutral pseudoscalar and vector meson in SU(3 lattice gauge theory in the strong abelian magnetic field. The energy of ρ0 meson with zero spin projection sz=0 on the axis of the external magnetic field decreases, while the energies with non-zero spins sz=−1 and +1 increase with the field. The energy of π0 meson decreases as a function of the magnetic field. We calculate the magnetic polarizabilities of pseudoscalar and vector mesons for lattice volume 184. For ρ0 with spin |sz|=1 and π0 meson the polarizabilities in the continuum limit have been evaluated. We do not observe any evidence in favour of tachyonic mode existence.

A survey of E/iota meson in hadroproduction

International Nuclear Information System (INIS)

Chung, S.U.

1987-01-01

The E(1420) meson has been around with us since 1963, when its observation was first reported by R. Armenteros et al. With the discovery of the iota(1460) in the same decay channel from J/ψ radiative decays in 1980, there has been a resurgence of interest in this meson because it may turn out to be a pseudoscalar glueball. This review covers the E/iota states seen in hadroproduction, while an update of the iota meson from J/ψ radiative decays is covered by D. Hitlin in this volume. The present review represents an updated version of the previous reviews given by the author at Lund, Leipzig, and Santander

Semileptonic Branching Fractions of Charged and Neutral B Mesons

International Nuclear Information System (INIS)

Athanas, M.; Brower, W.; Masek, G.; Paar, H.P.; Gronberg, J.; Kutschke, R.; Menary, S.; Morrison, R.J.; Nakanishi, S.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Ryd, A.; Tajima, H.; Sperka, D.; Witherell, M.S.; Balest, R.; Cho, K.; Ford, W.T.; Johnson, D.R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Drell, P.S.; Dumas, D.; Ehrlich, R.; Gaidarev, P.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Jones, C.D.; Jones, S.L.; Kandaswamy, J.; Katayama, N.; Kim, P.C.; Kreinick, D.L.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Patterson, J.R.; Peterson, D.; Riley, D.; Salman, S.; Sapper, M.; Wuerthwein, F.; Avery, P.; Freyberger, A.; Rodriguez, J.; Yang, S.; Yelton, J.; Cinabro, D.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Gollin, G.; Ong, B.; Palmer, M.; Selen, M.; Thaler, J.J.; Edwards, K.W.; Ogg, M.; Bellerive, A.; Britton, D.I.; Hyatt, E.R.F.; MacFarlane, D.B.; Patel, P.M.; Spaan, B.; Sadoff, A.J.; Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kotov, S.; Kravchenko, I.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Momayezi, M.; Nelson, J.K.; Patton, S.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Ling, Z.; Mahmood, A.H.; O'Neill, J.J.; Severini, H.; Sun, C.R.; Wappler, F.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Skovpen, Y.; Sung, M.; White, C.; Zoeller, M.M.; Butler, F.; Fu, X.; Nemati, B.; Ross, W.R.; Skubic, P.; Wood, M.; Bishai, M.; Fast, J.; Gerndt, E.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Gibbons, L.; Kwon, Y.

1994-01-01

An examination of leptons in Υ(4S) events tagged by reconstructed B meson decays yields semileptonic branching fractions of b - =(10.1±1.8±1.5)% for charged and b 0 =(10.9±0.7±1.1)% for neutral B mesons. This is the first measurement for charged B mesons. Assuming equality of the charged and neutral semileptonic widths, the ratio b - /b 0 =0.93±0.18±0.12 is equivalent to the ratio of lifetimes

Quasi-exotic open-flavor mesons

Energy Technology Data Exchange (ETDEWEB)

Hilger, T.; Krassnigg, A. [University of Graz, NAWI Graz, Institute of Physics, Graz (Austria)

2017-06-15

Meson states with exotic quantum numbers arise naturally in a covariant bound-state framework in QCD. We investigate the consequences of shifting quark masses such that the states are no longer restricted to certain C-parities, but only by J{sup P}. Then, a priori, one can no longer distinguish exotic or conventional states. In order to identify signatures of the different states to look for experimentally, we provide the behavior of masses, leptonic decay constants, and orbital-angular-momentum decomposition of such mesons, as well as the constellations in which they could be found. Most prominently, we consider the case of charged quasi-exotic excitations of the pion. (orig.)

A search for unconventional mesons

International Nuclear Information System (INIS)

Turnau, J.

1984-01-01

Selected problems of the fixed target meson spectroscopy connected with the issue of unconventional states glueballs, hybrides and four-quarks are discussed. The experimental basis of the dissertation consists of some results of the WA3 experiment performed by ACCMOR collaboration (Π - p→(3Π) - p, K - p→K - Π + Π - p, Π - p→K s o K s o n) and of the S136 experiment performed by CCM collaborations (Π - p↑→Π + Π - n, Π - p↑→K + K - n). Mesons with spin parities J PC = 0 -+ , 0 ++ , 1 ++ and 2 ++ are discussed from the point of view of the phenomenology of unconventional states. (author)

Properties of the ρ meson in dense nuclear matter

International Nuclear Information System (INIS)

Herrmann, M.

1992-05-01

In order to reach a description of the ρ meson, which is in accordance with the principles of the gauge invariance of the electromagnetic interaction, the vector-dominance hypothesis, and the unitarity a model for the ρ meson in the vacuum is developed. Thereafter follows the calculation of the properties of the ρ meson in nuclear matter. First the connection between the spectral function of the ρ meson and the dilepton production rate for an equilibrium state is derived. Then the model for the pion in nuclear matter is described. Following approximations are applied: The description of the pion-baryon interaction pursues non-relativistically and both the width of the delta resonance and the short-range repulsive delta-nucleon interaction is neglected. The self-energy of the ρ meson in nuclear matter following from this description is formally derived from the requirement to couple the ρ meson to a conserved current. The corrections for the 3-point and 4-point vertex resulting from this are calculated and discussed. Thereafter the physical consequences of the changed self-energy of the ρ meson in nuclear matter are considered. By means of the spectral function it is shown that up to the two-fold of the ground-state density the position of the resonance is nearly not changed. At still higher densities the resonances is a little shifted to higher energies. In the range of an invariant mass of about 400 meV a strong increasement concentrated on a small range results. This is caused by coupling to a naked delta-hole state and a pion. Finally the possibilities are discussed to apply the results of this thesis to the prediction of experimental data. Thereby it is proved to be necessary to base on a simulation of the heavy ion reaction. (orig./HSI) [de

Phases, quantum interferences and effective vector meson masses in nuclei

Energy Technology Data Exchange (ETDEWEB)

Soyeur, M.

1996-12-31

We discuss the prospects for observing the mass of {rho}- and {omega}-mesons around nuclear matter density by studying their coherent photoproduction in nuclear targets and subsequent in-medium decay into e{sup +}e{sup -}pairs. The quantum interference of {rho} and {omega}-mesons in the e{sup +}e{sup -}channel and the interference between Bethe-Heitler pairs and dielectrons from vector meson decays are of particular interest. (author). 21 refs.

Observation of a New Narrow Axial-Vector Meson alpha(1)(1420)

Czech Academy of Sciences Publication Activity Database

Adolph, C.; Akhunzyanov, R.; Alexeev, M.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Azevedo, C.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Birsa, R.; Bisplinghoff, J.; Bodlák, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Chang, W.-C.; Chiosso, M.; Choi, I.; Chung, S. U.; Cicuttin, A.; Crespo, M.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O.; Dhara, L.; Donskov, S. V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse-Perdekapm, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, E.; Hinterberger, F.; Horikawa, N.; d´Hose, N.; Hsieh, C.-Yu.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jarý, V.; Jörg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.; Marchand, C.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neyret, D.; Nikolaenko, V. I.; Nový, J.; Nowak, W. D.; Nunes, A.S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.-C.; Pereira, F.; Pešek, M.; Peshekhonov, D. V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rocco, E.; Rossiyskaya, N. S.; Ryabchikov, D.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schmeing, S.; Schmidt, K.; Schlüter, T.; Selyunin, A.; Schmieden, H.; Schönning, K.; Schopferer, S.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, Aleš; Stolarski, M.; Šulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Wallner, S.; Weisrock, T.; Wilfert, M.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

2015-01-01

Roč. 115, č. 8 (2015), 082001:1-6 ISSN 0031-9007 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : COMPASS * pion-nucleon scattering * hadron spectroscopy * light-meson spectrum * axial-vector mesons * exotic mesons Subject RIV: BH - Optics, Masers, Lasers Impact factor: 7.645, year: 2015

Limits on rare exclusive decays of B mesons

International Nuclear Information System (INIS)

Avery, P.; Besson, D.; Bowcock, T.; Giles, R.T.; Hassard, J.; Kinoshita, K.; Pipkin, F.M.; Wilson, R.; Wolinski, J.; Xiao, D.; Gentile, T.; Haas, P.; Hempstead, M.; Jensen, T.; Kagan, H.; Kass, R.; Behrends, S.; Guida, J.M.; Guida, J.A.; Morrow, F.; Poling, R.; Thorndike, E.H.; Tipton, P.; Alam, M.S.; Katayama, N.; Kim, I.J.; Sun, C.R.; Tanikella, V.; Bortoletto, D.; Chen, A.; Garren, L.; Goldberg, M.; Holmes, R.; Horwitz, N.; Jawahery, A.; Lubrano, P.; Moneti, G.C.; Sharma, V.; Csorna, S.E.; Mestayer, M.D.; Panvini, R.S.; Word, G.B.; Bean, A.; Bobbink, G.J.; Brock, I.C.; Engler, A.; Ferguson, T.; Kraemer, R.W.; Rippich, C.; Vogel, H.; Bebek, C.; Berkelman, K.; Blucher, E.; Cassel, D.G.; Copie, T.; DeSalvo, R.; DeWire, J.W.; Ehrlich, R.; Galik, R.S.; Gilchriese, M.G.D.; Gittelman, B.; Gray, S.W.; Halling, A.M.; Hartill, D.L.; Heltsley, B.K.; Holzner, S.; Ito, M.; Kandaswamy, J.; Kowalewski, R.; Kreinick, D.L.; Kubota, Y.; Mistry, N.B.; Mueller, J.; Namjoshi, R.; Nordberg, E.; Ogg, M.; Perticone, D.; Peterson, D.; Pisharody, M.; Read, K.; Riley, D.; Silverman, A.; Stone, S.; Yi Xia; Sadoff, A.J.

1987-01-01

We have set upper limits for rare exclusive decays of B mesons arising from higher order processes in the standard model of electroweak interactions. Such decays may occur via ''penguin diagrams'' in B decay. We also set an upper limit on a lepton-number-violating decay mode of the neutral B meson. (orig.)

Test of scalar meson structure in φ radiative decays

International Nuclear Information System (INIS)

Kumano, S.

1992-12-01

We show that φ radiative decays into scalar mesons [f 0 (975), a 0 (980) ≡ S] can provide important clues on the internal structures of these mesons. Radiative decay widths vary widely: B.R. = 10 -4 -10 -6 depending on the substructures (qq-bar, qqq-barq-bar, KK-bar, glueball). Hence, we could discriminate among various models by measuring these widths at future φ factories. The understanding of these meson structures is valuable not only in hadron spectroscopy but also in nuclear physics in connection with the widely-used but little-understood σ meson. We also find that the decay φ→S γ →K 0 K-bar 0 γ is not strong enough to pose a significant background problem for studying CP violation via φ→K 0 K-bar 0 at the φ factories. (author)

Measurement of the total cross section for the photoproduction of omega mesons on the proton; Messung des totalen Wirkungsquerschnitts fuer die Photoproduktion von Omegamesonen am Proton

Energy Technology Data Exchange (ETDEWEB)

Hoeffgen, S.K.

2007-06-15

The photoproduction of omega mesons on the proton ({gamma}p {yields} {omega}p) directly at the production threshold was investigated during the first phase of the CB-ELSA experiment in Bonn. In experiments directly at the threshold the protons are strongly focussed in forward direction due to kinematic reasons. Therefore the forward detector, a large area time of flight detector, plays a prominent role and there is a detailed description of the reconstruction and measuring capabilities of this spectrometer. Thereafter follows the extraction of the total cross section of the reaction {gamma}p {yields} {omega}p in the decay channel with {omega} {yields} {pi}{sup 0}{pi}{sup +}{pi}{sup -} directly at the production threshold with previously unequaled accuracy. (orig.)

Determining the meson-nucleus potential - on the way to mesic states

Energy Technology Data Exchange (ETDEWEB)

Metag, Volker, E-mail: volker.metag@exp2.physik.uni-giessen.de [Universität Giessen, II. Physikalisches Institut (Germany)

2015-08-15

Experimental approaches to determine the real and imaginary part of the meson-nucleus potential are described. The experiments have been performed with the Crystal Barrel/TAPS detector at the electron accelerator ELSA (Bonn) and the Crystal Ball/TAPS detector at MAMI (Mainz). Measuring the transparency ratio as well as the excitation function and momentum distribution for photo production of ω and η′ mesons, the imaginary part of the η′-nucleus potential is found to be smaller than the real part. In case of the ω meson the opposite is observed. This makes the η′ meson a good candidate for the search for meson-nucleus bound states while no resolved ω mesic states can be expected. The results are discussed and compared to theoretical predictions. An outlook on future experiments is given.

Latest results from meson photoproduction at ELSA and MAMI

Science.gov (United States)

Krusche, B.

2014-06-01

Photoproduction of mesons plays a key role for the investigation of the excitation spectrum of the nucleon and thus for our understanding of the strong interaction in the non-perturbative regime. In this contribution we discuss recent results from the experiments at the tagged photon beams of the electron accelerators ELSA in Bonn and MAMI in Mainz. They include the measurement of cross sections and (double) polarization observables for single meson production and production of meson pairs off free protons as well as of quasi-free nucleons bound in light nuclei (in particular the deuteron).

Muoproduction of J/ψ-mesons and the gluon distribution in nucleons

International Nuclear Information System (INIS)

Jong, Maarten de.

1991-01-01

The cross sections for production of J/ψ-mesons in muon-scattering at hydrogen and deuterium have been measured at a muon-energy of 280 GeV in order to extract from these the momentum distribution of gluons in the nucleon. These cross sections turned out to be equal for protons and neutrons within the experimental error. In the framework of the colour singlet model the gluon distribution has been determined from the cross section for the inelastic production of J/ψ mesons. At small gluon impulses the distribution obtained resembles a brems-strahlung spectrum. This distribution decreases, according to a simple description (counting rules) at larger impulses. The same model however underestimates the cross section for elastic production of J/ψ-mesons seriously. It is found that in inelastic production of J/ψ-mesons both helicities of the meson occur equally. Also a correlation has been observed between the scattering plane and the plane in which the J/ψ meson decays. The production of J/ψ-mesons and ψ'-mesons has been investigated in muon scattering at concrete at the same incoming energy. The measured ratio of their cross sections agrees with the colour singlet model but disagrees with the simplified description which characterizes the 'photon-gluon fusion model'. The possible nuclear-mass dependence of the cross section for J/ψ-meson production has been investigated in interactions of muons with tin and carbon at an energy of 280 GeV. This possible dependence turns out to be absent which means that on the basis of the colour singlet model the distributions of the gluons in the nucleon are equal in tin and carbon. (author). 103 refs.; 60 figs.; 19 tabs

Nonleptonic B decays involving tensor mesons

Energy Technology Data Exchange (ETDEWEB)

Lopez Castro, G. [Departamento de Fisica, Cinvestav del IPN, Apdo. Postal 14-740, 07000 Mexico, D.F. (Mexico); Munoz, J.H. [Departamento de Fisica, Cinvestav del IPN, Apdo. Postal 14-740, 07000 Mexico, D.F. (Mexico)]|[Departamento de Fisica, Universidad del Tolima, A.A. 546, Ibague (Colombia)

1997-05-01

Two-body nonleptonic decays of B mesons into PT and VT modes are calculated using the nonrelativistic quark model of Isgur {ital et al.} The predictions obtained for B{r_arrow}{pi}D{sub 2}{sup {asterisk}},{rho}D{sub 2}{sup {asterisk}} are a factor of 3{endash}5 below present experimental upper limits. Interesting patterns are obtained for ratios of B decays involving mesons with different spin excitations and their relevance for additional tests of forms factor models are briefly discussed. {copyright} {ital 1997} {ital The American Physical Society}

Quasi two-body decays of D0 meson

International Nuclear Information System (INIS)

Terasaki, K.; Oneda, S.

1985-08-01

Quasi two-body decays of D 0 -meson are studied from an algebraic approach, using a hard meson extrapolation. In this innovation of old current algebra with new perspective, a reasonable unified description of K sub(S) → 2π and D 0 → K-barπ decays has been obtained previously, keeping only the contribution of ground state mesons to the now surviving surface term. In this paper, it is shown that quasi two-body decays can also be accomodated reasonably well in the same scheme. A distinctive feature of our result is that GAMMA(D 0 → phi K-bar 0 ) is sizable, while D 0 → rho 0 K-bar 0 is relatively suppressed. (author)

Meson-Baryon Scattering Lengths from Mixed-Action Lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Beane, S; Detmold, W; Luu, T; Orginos, K; Parreno, A; Torok, A; Walker-Loud, A

2009-06-30

The {pi}{sup +}{Sigma}{sup +}, {pi}{sup +}{Xi}{sup 0}, K{sup +}p, K{sup +}n, {bar K}{sup 0}{Sigma}{sup +}, and {bar K}{sup 0}{Xi}{sup 0} scattering lengths are calculated in mixed-action Lattice QCD with domain-wall valence quarks on the asqtad-improved coarse MILC configurations at four light-quark masses, and at two light-quark masses on the fine MILC configurations. Heavy Baryon Chiral Perturbation Theory with two and three flavors of light quarks is used to perform the chiral extrapolations. We find no convergence for the kaon-baryon processes in the three-flavor chiral expansion. Using the two-flavor chiral expansion, we find a{sub {pi}{sup +}{Sigma}{sup +}} = -0.197 {+-} 0.017 fm, and a{sub {pi}{sup +}{Xi}{sup 0}} = -0.098 {+-} 0.017 fm, where the comprehensive error includes statistical and systematic uncertainties.

Light Meson Distribution Amplitudes

CERN Document Server

Arthur, R.; Brommel, D.; Donnellan, M.A.; Flynn, J.M.; Juttner, A.; de Lima, H.Pedroso; Rae, T.D.; Sachrajda, C.T.; Samways, B.

2010-01-01

We calculated the first two moments of the light-cone distribution amplitudes for the pseudoscalar mesons ($\\pi$ and $K$) and the longitudinally polarised vector mesons ($\\rho$, $K^*$ and $\\phi$) as part of the UKQCD and RBC collaborations' $N_f=2+1$ domain-wall fermion phenomenology programme. These quantities were obtained with a good precision and, in particular, the expected effects of $SU(3)$-flavour symmetry breaking were observed. Operators were renormalised non-perturbatively and extrapolations to the physical point were made, guided by leading order chiral perturbation theory. The main results presented are for two volumes, $16^3\\times 32$ and $24^3\\times 64$, with a common lattice spacing. Preliminary results for a lattice with a finer lattice spacing, $32^3\\times64$, are discussed and a first look is taken at the use of twisted boundary conditions to extract distribution amplitudes.

Chiral symmetry breaking and the spin content of the ρ and ρ' mesons

International Nuclear Information System (INIS)

Glozman, L.Ya.; Lang, C.B.; Limmer, M.

2011-01-01

Using interpolators with different SU(2) L xSU(2) R transformation properties we study the chiral symmetry and spin contents of the ρ and ρ ' mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar γ i τq and q-bar σ 0i τq interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of ∼1 fm. In the ground state ρ meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2) b chiral representations with the former being the leading contribution. In contrast, in the ρ ' meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2) b . Using a unitary transformation from the chiral basis to the 2S+1 L J basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The ρ meson is practically a 3 S 1 state with no obvious trace of a 'spin crisis'. The ρ ' meson has a sizeable contribution of the 3 D 1 wave, which implies that the ρ ' meson cannot be considered as a pure radial excitation of the ρ meson.

Electro- and chromomagnetism in the charm meson spectrum

CERN Document Server

Fritzsch, Harald

1977-01-01

How the D and F meson spectrum is influenced by the chromomagnetic and electromagnetic hyperfine interaction is discussed. In particular a relation between the hyperfine splitting of charmed mesons and the magnetic moments of the baryons is derived. It is found that M(F/sub + /*)-M(F/sub +/) approximately=100+or-8 MeV. (12 refs).

Recent trends in the mesonic description of nuclei

International Nuclear Information System (INIS)

Delorme, J.

1985-07-01

A survey is given of some recent developments in the domain of meson induced phenomena in nuclei. The manifestations of mesonic degrees of freedom are considered in the context of exchange currents as well as that of effective interactions. The significance of past successes is reexamined in the light of recent progress towards a QCD based nuclear theory

First measurement of the B S meson mass

Science.gov (United States)

Buskulic, D.; De Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Haywood, S.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Lohse, T.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Veenhof, R.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Sawyer, L.; Wasserbaech, S.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jacobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Carter, J. M.; Gao, Y.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Cinabro, D.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; LeClaire, B. W.; Lishka, C.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Sharma, V.; Shi, Z. H.; Walsh, A. M.; Weber, F. V.; Wu, Sau Lan; Wu, X.; Zheng, M.; Zobernig, G.

1993-07-01

In a sample of about 1.1 million hadronic Z decays recorded with the ALEPH detector during the 1990-1992 running of LEP, two unambiguous B S meson candidates were observed. From these events the mass of the B S meson has been measured to be 5.3686 ± 0.0056 (stat.) ± 0.0015 (syst.) GeV.

Production of φ-Mesons in anti NN-Annihilation

International Nuclear Information System (INIS)

Sapozhnikov, M.G.

1994-01-01

Recent results from the experiments on the φ-meson production in the annihilation of stopped antiprotons have demonstrated a significant (by a factor of 30-50) violation of the OZI rule. Experimental information on the φ-meson production is discussed and possible theoretical explanations of the strong OZI rule violation are reviewed. 37 refs., 4 figs., 2 tabs

Perspectives of Scalar- and Vector- Meson Production in Hadron-Nucleus Reactions

International Nuclear Information System (INIS)

Cassing, W.

2000-01-01

The production and decay of vector mesons (ρ, ω) in pA reactions at COSY energies is studied with particular emphasis on their in-medium spectral functions. It is explored within transport calculations, if hadronic in-medium decays like π + π - or π 0 γ might provide complementary information to their dilepton (e + e - ) decays. Whereas the π + π - signal from the ρ-meson is found to be strongly distorted by pion rescattering, the ω- meson Dalitz decay to π 0 γ appears promising even for more heavy nuclei. The perspectives of scalar meson ( f 0 , a 0 ) production in pp reactions are investigated within a boson-exchange model indicating that the f 0 -meson might hardly be detected in these collisions in the K(anti)K or ππ decay channels whereas the exclusive channel pp→da 0 + looks very promising. (author)

The effect of meson wave function on heavy-quark fragmentation function

Energy Technology Data Exchange (ETDEWEB)

Moosavi Nejad, S.M. [Yazd University, Faculty of Physics (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, Tehran (Iran, Islamic Republic of)

2016-05-15

We calculate the process-independent fragmentation functions (FFs) for a heavy quark to fragment into heavy mesons considering the effects of meson wave function. In all previous works, where the FFs of heavy mesons or heavy baryons were calculated, a delta function form was approximated for the wave function of hadrons. Here, for the first time, we consider a typical mesonic wave function which is different from the delta function and is the nonrelativistic limit of the solution of Bethe-Salpeter equation with the QCD kernel. We present our numerical results for the heavy FFs and show how the proposed wave function improves the previous results. As an example, we focus on the fragmentation function for c-quark to split into S-wave D{sup 0} -meson and compare our results with experimental data from BELLE and CLEO. (orig.)

Meson life time in the anisotropic quark-gluon plasma

International Nuclear Information System (INIS)

Ali-Akbari, Mohammad; Allahbakhshi, Davood

2014-01-01

In the hot (an)isotropic plasma the meson life time τ is defined as a time scale after which the meson dissociates. According to the gauge/gravity duality, this time can be identified with the inverse of the imaginary part of the frequency of the quasinormal modes, ω_I, in the (an)isotropic black hole background. In the high temperature limit, we numerically show that at fixed temperature(entropy density) the life time of the mesons decreases(increases) as the anisotropy parameter raises. For general case, at fixed temperature we introduce a polynomial function for ω_I and observe that the meson life time decreases. Moreover, we realize that (s/T"3)"6, where s and T are entropy density and temperature of the plasma respectively, can be expressed as a function of anisotropy parameter over temperature. Interestingly, this function is a Padé approximant.

Meson-exchange N-N potential

International Nuclear Information System (INIS)

Nutt, W.T.

1976-01-01

A meson-theoretic model of the intermediate range nucleon-nucleon potential is presented with emphasis placed on the two-pion exchange contribution. The Bethe-Salpeter equation is reduced, by the Blankenbecler-Sugar technique, to a Lippmann-Schwinger equation, from which an approximate nonlocal, energy-dependent potential is obtained. The nucleon-antinucleon pair contribution, which plagues meson-theoretical two-pion calculations, is suppressed by the complex poles of the one-nucleon Green's function. The importance of the retention of the explicit energy dependence of the potential is demonstrated by calculating the off-shell scattering matrices. The potential is presented in a linearized (in energy) form with the core region adjusted to produce a fit to low energy data

Isospin breaking in the pion-nucleon coupling constant and the nucleon-nucleon scattering length

Directory of Open Access Journals (Sweden)

V. A. Babenko

2016-08-01

Full Text Available Charge independence breaking (CIB in the pion-nucleon coupling constant and the nucleon-nucleon scattering length is considered on the basis of the Yukawa meson theory. CIB effect in these quantities is almost entirely explained by the mass difference between the charged and the neutral pions. Therewith charge splitting of the pion-nucleon coupling constant is almost the same as charge splitting of the pion mass. Calculated difference between the proton-proton and the neutron-proton scattering length in this case comprises ∼90% of the experimental value.

The Rainich problem for coupled gravitational and scalar meson fields

International Nuclear Information System (INIS)

Hyde, J.M.

1975-01-01

The equations of the coupled gravitational and scalar meson fields in general relativity are considered. It is shown that the wave equation for the scalar meson field which is usually specified explicitly in addition to the Einstein field equations is implied by Einstein's equations. Using this result it is then shown how the scalar field may be eliminated explicitly from the field equations, thus solving the Rainich problem for the coupled gravitational and scalar meson fields. (author) [fr

Future prospects for studying CP violation in B-meson decays

International Nuclear Information System (INIS)

Nakada, T.

1997-01-01

Experimental prospects for observing CP violation in B-meson decays are reviewed. Comparisons are made for various options: experiments a e + e - B-Meson Factories, HERA and the TEVATRON will produce results n near future. They will have a good chance to discover CP violation in B-meson decays. On a longer time scale, experiments at the LHC will aim at accurate measurements to make a precision test of the standard model in CP violation. (author)

Magnetic monopole interactions: shell structure of meson and baryon states

International Nuclear Information System (INIS)

Akers, D.

1986-01-01

It is suggested that a low-mass magnetic monopole of Dirac charge g = (137/2)e may be interacting with a c-quark's magnetic dipole moment to produce Zeeman splitting of meson states. The mass M 0 = 2397 MeV of the monopole is in contrast to the 10 16 -GeV monopoles of grand unification theories (GUT). It is shown that shell structure of energy E/sub n/ = M 0 + 1/4nM 0 ... exists for meson states. The presence of symmetric meson states leads to the identification of the shell structure. The possible existence of the 2397-MeV magnetic monopole is shown to quantize quark masses in agreement with calculations of quantum chromodynamics (QCD). From the shell structure of meson states, the existence of two new mesons is predicted: eta(1814 +/- 50 MeV) with I/sup G/(J/sup PC/) = 0 + (0 -+ ) and eta/sub c/ (3907 +/- 100 MeV) with J/sup PC/ = 0 -+ . The presence of shell structure for baryon states is shown

Masses of scalar and axial-vector B mesons revisited

Energy Technology Data Exchange (ETDEWEB)

Cheng, Hai-Yang [Academia Sinica, Institute of Physics, Taipei (China); Yu, Fu-Sheng [Lanzhou University, School of Nuclear Science and Technology, Lanzhou (China)

2017-10-15

The SU(3) quark model encounters a great challenge in describing even-parity mesons. Specifically, the q anti q quark model has difficulties in understanding the light scalar mesons below 1 GeV, scalar and axial-vector charmed mesons and 1{sup +} charmonium-like state X(3872). A common wisdom for the resolution of these difficulties lies on the coupled channel effects which will distort the quark model calculations. In this work, we focus on the near mass degeneracy of scalar charmed mesons, D{sub s0}{sup *} and D{sub 0}{sup *0}, and its implications. Within the framework of heavy meson chiral perturbation theory, we show that near degeneracy can be qualitatively understood as a consequence of self-energy effects due to strong coupled channels. Quantitatively, the closeness of D{sub s0}{sup *} and D{sub 0}{sup *0} masses can be implemented by adjusting two relevant strong couplings and the renormalization scale appearing in the loop diagram. Then this in turn implies the mass similarity of B{sub s0}{sup *} and B{sub 0}{sup *0} mesons. The P{sub 0}{sup *}P{sub 1}{sup '} interaction with the Goldstone boson is crucial for understanding the phenomenon of near degeneracy. Based on heavy quark symmetry in conjunction with corrections from QCD and 1/m{sub Q} effects, we obtain the masses of B{sup *}{sub (s)0} and B{sup '}{sub (s)1} mesons, for example, M{sub B{sub s{sub 0{sup *}}}} = (5715 ± 1) MeV + δΔ{sub S}, M{sub B}{sup {sub '{sub s{sub 1}}}} = (5763 ± 1) MeV + δΔ{sub S} with δΔ{sub S} being 1/m{sub Q} corrections. We find that the predicted mass difference of 48 MeV between B{sup '}{sub s1} and B{sub s0}{sup *} is larger than that of 20-30 MeV inferred from the relativistic quark models, whereas the difference of 15 MeV between the central values of M{sub B}{sup {sub '{sub s{sub 1}}}} and M{sub B}{sup {sub '{sub 1}}} is much smaller than the quark model expectation of 60-100 MeV. Experimentally, it is important to have a precise

Cabibbo-Kobayashi-Maskawa-favored B decays to a scalar meson and a D meson

Energy Technology Data Exchange (ETDEWEB)

Zou, Zhi-Tian; Li, Ying [Yantai University, Department of Physics, Yantai (China); Liu, Xin [Jiangsu Normal University, School of Physics and Electronic Engineering, Xuzhou (China)

2017-12-15

In this work, we attempt to study the Cabibbo-Kobayashi-Maskawa-favored B → anti DS (''S'' denoting the scalar meson) decays within the perturbative QCD approach at the leading order and the leading power. Although the light scalar mesons are widely perceived as primarily the four-quark bound states, in practice it is hard for us to make quantitative predictions based on the four-quark picture for light scalars. Hence, we calculate the decays with light scalars in the two-quark model. For the decays with scalar mesons above 1 GeV, we have explored two possible scenarios, depending on whether the light scalars are treated as the lowest lying q anti q states or four-quark particles. In total, we calculated the branching fractions of 72 decay modes, and most of them are in the range 10{sup -4}-10{sup -7}, which are measurable in the on-going LHCb experiment and the forthcoming Belle-II experiment. Moreover, since in the standard model these decays occur only through tree operators and have no CP asymmetries, any deviation will be a signal of new physics beyond the standard model. Despite large uncertainties induced by nonperturbative parameters and corrections of high order and high power, our results and discussions will be useful for the on-going LHCb and the forthcoming Belle-II experiments. (orig.)

Vector meson photoproduction with a linearly polarized beam

Science.gov (United States)

Mathieu, V.; Nys, J.; Fernández-Ramírez, C.; Jackura, A.; Pilloni, A.; Sherrill, N.; Szczepaniak, A. P.; Fox, G.; Joint Physics Analysis Center

2018-05-01

We propose a model based on Regge theory to describe photoproduction of light vector mesons. We fit the SLAC data and make predictions for the energy and momentum-transfer dependence of the spin-density matrix elements in photoproduction of ω , ρ0 and ϕ mesons at Eγ˜8.5 GeV , which are soon to be measured at Jefferson Lab.

The vector meson with anomalous magnetic moment

International Nuclear Information System (INIS)

Boyarkin, O.M.

1976-01-01

The possibility of introducing an anomalous magnetic moment into the Stuckelberg version of the charged vector meson theory is considered. It is shown that the interference of states with spins equal to one and zero is absent in the presence of an anomalous magnetic moment of a particle. The differential cross section of scattering on the Coulomb field of a nucleus is calculated, and so are the differential and integral cross sections of meson pair production on annihilation of two gamma quanta. The two-photon mechanism of production of a meson pair in colliding electron-positron beams is considered. It is shown that with any value of the anomalous magnetic moment the cross section of the esup(+)esup(-) → esup(+)esup(-)γsup(*)γsup(*) → esup(+)esup(-)Wsup(+)Wsup(-) reaction exceeds that of the esup(+)esup(-) → γsup(*) → Wsup(+)Wsup(-) at sufficiently high energies

Importance of Nonperturbative QCD Parameters for Bottom Mesons

Directory of Open Access Journals (Sweden)

A. Upadhyay

2014-01-01

Full Text Available The importance of nonperturbative quantum chromodynamics (QCD parameters is discussed in context to the predicting power for bottom meson masses and isospin splitting. In the framework of heavy quark effective theory, the work presented here focuses on the different allowed values of the two nonperturbative QCD parameters used in heavy quark effective theory formula, and using the best fitted parameter, masses of the excited bottom meson states in jp=1/2+ doublet in strange and nonstrange sectors are calculated here. The calculated masses are found to be matching well with experiments and other phenomenological models. The mass splitting and hyperfine splitting have also been analyzed for both strange and nonstrange heavy mesons with respect to spin and flavor symmetries.

Melting spectral functions of the scalar and vector mesons in a holographic QCD model

International Nuclear Information System (INIS)

Fujita, Mitsutoshi; Kikuchi, Toru; Fukushima, Kenji; Misumi, Tatsuhiro; Murata, Masaki

2010-01-01

We investigate the finite-temperature spectral functions of heavy quarkonia by using the soft-wall anti-de Sitter/QCD model. We discuss the scalar, the pseudoscalar, the vector, and the axial-vector mesons and compare their qualitative features of the melting temperature and growing width. We find that the axial-vector meson melts earlier than the vector meson, while there appears only a slight difference between the scalar and pseudoscalar mesons, which also melt earlier than the vector meson.

On the possibility of thermalization of heavy mesons in ultrarelativistic nuclear collisions

Energy Technology Data Exchange (ETDEWEB)

Lokhtin, I. P., E-mail: Igor.Lokhtin@cern.ch; Belyaev, A. V. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Ponimatkin, G. [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering (Czech Republic); Pronina, E. Yu.; Eiyubova, G. Kh. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2017-02-15

The phenomenological analysis and interpretation of experimental data from RHIC and LHC on the production of J/ψ and D mesons in heavy-ion collisions are performed within the two-component HYDJET++ model including the thermal and hard mechanisms of hadron production. It is shown that the thermal freeze-out of charmed mesons at RHIC energies occurs earlier than the thermal freeze-out of light hadrons (assumingly, simultaneously with chemical freeze-out), which indicates that J/ψ and D mesons are not in kinetic equilibrium with the formed hadronic matter. At the same time, a significant part of D mesons at LHC energies are in kinetic equilibrium with the formed thermalized matter, but J/ψ mesons are still characterized by early freeze-out.

Isospin-violating mixing in meson nonets

International Nuclear Information System (INIS)

Isgur, N.

1979-01-01

Segregation into ideally mixed nonets results when the OZI-violating interaction which would mix u anti u, d anti d, and s anti s mesons into isospin and SU(3) eigenstates is much weaker than the s anti s-d anti d mass difference. We show that the d anti d-u anti u mass difference can begin to induce a similar segregation into d anti d and anti u mesons which leads to large isospin violations. An experimental example of such large isospin breaking (approx. 30%) which we predict has probably already been seen in f → K anti K. (orig.)

Instanton and tensor-force effects in the strong decays of mesons

International Nuclear Information System (INIS)

Bonnaz, R.; Silvestre-Brac, B.

2001-01-01

The strong decays of mesons are studied in the framework of the 3 P 0 model with a momentum-dependent vertex. The mesons wave functions are obtained from quark-antiquark potentials including a finite quark size, instanton effects, spin-orbit and tensor-force effects. Several prescriptions for treating the decays into three mesons are proposed and analyzed. Comparison to experimental data is presented in detail. (author)

Measurement of D-meson azimuthal anisotropy in Au + Au 200 GeV collisions at RHIC

Science.gov (United States)

Lomnitz, Michael

2016-12-01

Heavy quarks are produced through initial hard scatterings and they are affected by the hot and dense medium created in heavy-ion collisions throughout its whole evolution. Due to their heavy mass, charm quarks are expected to thermalize much more slowly than light flavor quarks. The charm quark flow is a unique tool to study the extent of thermalization of the bulk medium dominated by light quarks and gluons. At high pT, D-meson azimuthal anisotropy is sensitive to the path length dependence of charm quark energy loss in the medium, which offers new insights into heavy quark energy loss mechanisms - gluon radiation vs. collisional processes. We present the STAR measurement of elliptic flow (v2) of D0 and D± mesons in Au+Au collisions at √{sNN} = 200 GeV, for a wide transverse momentum range. These results are obtained from the data taken in the first year of physics running of the new STAR Heavy Flavor Tracker detector, which greatly improves open heavy flavor hadron measurements by the topological reconstruction of secondary decay vertices. The D-meson v2 is finite for pT > 2 GeV/c and systematically below the measurement of light particle species at the same energy. Comparison to a series of model calculations favors scenarios where charm flows with the medium and is used to infer a range for the charm diffusion coefficient 2 πTDs.

The reactions ππ → ππ and γγ → ππ χPT with an isosinglet scalar resonance

Energy Technology Data Exchange (ETDEWEB)

Thapaliya, Arbin [Franklin College, Department of Chemistry and Physics, Franklin, IN (United States); Ohio University, Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Athens, OH (United States); Phillips, Daniel R. [Ohio University, Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Athens, OH (United States)

2017-10-15

The lowest-lying resonance in the QCD spectrum is the 0{sup ++} isoscalar σ-meson, also known as the f{sub 0}(500). We augment SU(2) chiral perturbation theory (χPT) by including the σ-meson as an additional explicit degree of freedom, as proposed by Soto, Talavera, and Tarrus and others. In this effective field theory, denoted χPT{sub S}, the σ-meson's well-established mass and decay width are not sufficient to properly renormalize its self energy. At O(p{sup 4}) another low-energy constant appears in the dressed σ-meson propagator; we adjust it so that the isoscalar pion-pion scattering length is also reproduced. We compare the resulting amplitudes for the ππ → ππ and γγ → ππ reactions to data from threshold through the energies at which the σ-meson resonance affects observables. The leading-order (LO) ππ amplitude reproduces the σ-meson pole position, the isoscalar ππ scattering lengths and ππ scattering and γγ → ππ data up to √(s) ∼ 0.5 GeV. It also yields a γγ → ππ amplitude that obeys the Ward identity. The value obtained for the π{sup 0} polarizability is, however, only slightly larger than that obtained in standard χPT. (orig.)

Low energy parameters of the K K-bar and ππ scalar-isoscalar interactions

International Nuclear Information System (INIS)

Kaminski, R.; Lesniak, L.

1994-06-01

Threshold expansions of the ππ and K K-bar spin 0 and isospin 0 scattering amplitudes are performed. Scattering lengths, effective ranges and so-called volume parameters are evaluated. Good agreement with the existing experimental data for the ππ scalar-isoscalar amplitude is found. An importance of future accurate measurements of the K K-bar threshold parameters is stressed. New data are needed to understand the basic features of the scalar mesons. (author). 31 refs, 3 tabs

Properties of vector and axial-vector mesons from a generalized Nambu-Jona-Lasinio model

International Nuclear Information System (INIS)

Bernard, V.; Meissner, U.G.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge

1988-01-01

We construct a generalized Nambu-Jona-Lasinio lagrangian including scalar, pseudoscalar, vector and axial-vector mesons. We specialize to the two-flavor case. The properties of the structured vacuum as well as meson masses and coupling constants are calculated giving an overall agreement within 20% of the experimental data. We investigate the meson properties at finite density. In contrast to the mass of the scalar σ-meson, which decreases sharply with increasing density, the vector meson masses are almost independent of density. Furthermore, the vector-meson-quark coupling constants are also stable against density changes. We point out that these results imply a softening of the nuclear equation of state at high densities. Furthermore, we discuss the breakdown of the KFSR relation on the quark level as well as other deviations from phenomenological concepts such as universality and vector meson dominance. (orig.)

Vector mesons in reactions with colliding electron-positron beams

International Nuclear Information System (INIS)

Rekalo, M.P.; Gakh, G.I.

1980-01-01

Polarization phenomena in the processes of vector meson production in reactions with colliding electron-positron beams e + e - → V+X, where V is a vector meson, X is a nondetected set of particles are investigated. For the one-photon mechanism of the process, where V and X are hadrons, the mutually unambiguous correspondence between the structural functions is found. The dependence of the e + e - → VX differential cross section upon the electron and positron polarizations is calculated using the virtual photon density matrix in the helicity basis. This formalism permits to take explicitly into account the P-invariance consequences for the angular distribution of the V-meson decay products. For the processes e + e - → πA 1 , and e + e - → rho + rho - the structural functions are calculated in terms of the corresponding electromagnetic form factors. It is noted that six functions out ten real structural functions describing the e + e - → VX reaction can be determined by means of investigation of the angular distribution of the V-meson decay products which is produced in collisions of unpolarized leptons. To study the collision of polarized leptons one more structural function can be determined. The formation of the X system with definite values of parity and spin is characterized by seven structural functions, five of which can be found while studying the angular distribution of the V-meson decay products produced in e + e - collisions with unpolarized (polarized) particles. If the spin of the X state is 1, in experiments with polarized beams all structural functions can be determined while investigating the angular distribution of the V-meson decay products

Near-threshold quantization and scattering for deep potentials with attractive tails

International Nuclear Information System (INIS)

Eltschka, Christopher; Moritz, Michael J.; Friedrich, Harald

2000-01-01

Near-threshold properties of bound and continuum states in a deep potential with an attractive tail depend essentially on a few 'tail parameters', which are determined by the properties of the potential tail beyond the region of r-values where WKB wavefunctions are accurate solutions of the Schroedinger equation. One of these tail parameters is a length parameter which defines the singular contribution to the level density just below threshold and the reflectivity of the tail of the potential just above threshold; another is a phase difference which, together with the length parameter, determines the mean scattering length. The near-threshold quantization rule and the actual scattering length are determined by the tail parameters together with a dimensionless constant depending on the zero-energy value of the WKB action integral. We study potentials with tails consisting of two inverse-power terms, V(r)∼-C α /r α -C α 1 /r α 1 ,α 1 >α>2and we derive exact analytical expressions for the tail parameters in the special case α 1 =2(α-1). This enables us to demonstrate the effect of a significant non-homogeneity of the potential tail on the results derived previously for homogeneous tails. (author)

Meson (photo- and) electro-production and the structure of nuclei at short distances

International Nuclear Information System (INIS)

Laget, J.M.

1985-09-01

The present status and the future prospects of the studies of very inelastic electronuclear reaction are reviewed, when both high energy and high momentum are transferred to the nucleus. Real and virtual mesons are tested on the same footing. Real meson production allows us to study the propagation of baryonic and mesonic resonances in nuclei and to put constraints on their interaction with the nucleon. Virtual meson creation is an alternative way to deal with exchange currents. The first lecture deals with the elementary operators, which describe meson photo- and electroproduction on free nucleons. The second one deals with real meson- photo- and electroproduction on few-body systems. Only the main features are discussed here and the last developments are presented. The third lecture deals with the coupling of the electromagnetic probe to the virtual meson in nuclei. The emphasis is put on the few-body systems, since their nuclear wave functions are known and since they are simple enough to allow for elaborate calculations. The case of heavy nuclei is also discussed. In the last lecture, I will try to look for evidence of the limits and the breakdown of the description of nuclei in terms of nucleons and mesons, and to forecast the new developments

D meson hadronic decays at CLEO-c

Energy Technology Data Exchange (ETDEWEB)

Yang, Fan; /Fermilab

2011-01-01

The recent CLEO-c results on hadronic decays of D and D{sub s} mesons are presented. First the absolute branching fractions for D and D{sub s} mesons using a double tag technique are discussed, then are the Cabibbo suppressed decays and doubly Cabibbo suppressed decays. Finally, I present the inclusive and rare decay modes and other measurements from CLEO-c. These decays illuminate a wide range of physics. A brief theoretical introduction is given before the corresponding discussion on measurement.

Using anti pp annihilation to find exotic mesons

International Nuclear Information System (INIS)

Sharpe, S.R.

1987-10-01

Present data suggests that a number of mesons have been found which cannot be accommodated in standard anti qq multiplets. Theory suggests that such exotic mesons should exist in the spectrum of Quantum Chromodynamics, but provides little guide to their properties. It is argued that a high luminosity, low energy anti pp machine would be a powerful tool with which to search for such exotics

Excited meson spectroscopy with two chirally improved quarks

Science.gov (United States)

Engel, G.; Lang, C. B.; Mohler, D.; Limmer, M.; Schäfer, A.

The excited isovector meson spectrum is explored using two chirally improved dynamical quarks. Seven ensembles, with pion masses down to \\approx 250 MeV are discussed and used for extrapolations to the physical point. Strange mesons are investigated using partially quenched s-quarks. Using the variational method, we extract excited states in several channels and most of the results are in good agreement with experiment.

Meson-induced correlations of nucleons in nuclear Compton scattering

International Nuclear Information System (INIS)

Huett, M.; Milstein, A.I.

1998-01-01

The nonresonant (seagull) contribution to the nuclear Compton amplitude at low energies is strongly influenced by nucleon correlations arising from meson exchange. We study this problem in a modified Fermi gas model, where nuclear correlation functions are obtained with the help of perturbation theory. The dependence of the mesonic seagull amplitude on the nuclear radius is investigated and the influence of a realistic nuclear density on this amplitude is discussed. We found that different form factors appear for the static part (proportional to the enhancement constant κ) of the mesonic seagull amplitude and for the parts, which contain the contribution from electromagnetic polarizabilities. copyright 1998 The American Physical Society

A calculation of the physical mass of sigma meson

International Nuclear Information System (INIS)

Morones-Ibarra, J.R.; Santos-Guevara, Ayax

2007-01-01

We calculate the physical mass and the width of the sigma meson by considering that it couples in vacuum to two virtual pions. The mass is calculated by using the spectral function, and we find that it is about 600 MeV. In addition, we obtained 220 MeV as the value for the width of its spectral function. The value obtained for the mass is in good agreement with that reported in the Particle Data Book for the σ meson, which is also named f 0 (600). This result also shows that σ-meson can be considered as a two-pion resonance. (author)

Measurement of the B+ and B0 meson lifetimes

International Nuclear Information System (INIS)

Abe, F.; Albrow, M.; Amidei, D.; Anway-Wiese, C.; Apollinari, G.; Areti, H.; Auchincloss, P.; Azfar, F.; Azzi, P.; Bacchetta, N.; Badgett, W.; Bailey, M.W.; Bao, J.; de Barbaro, P.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Bartalini, P.; Bauer, G.; Baumann, T.; Bedeschi, F.; Behrends, S.; Belforte, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Benlloch, J.; Benton, D.; Beretvas, A.; Berge, J.P.; Bertolucci, S.; Bhatti, A.; Biery, K.; Binkley, M.; Bird, F.; Bisello, D.; Blair, R.E.; Blocker, C.; Bodek, A.; Bolognesi, V.; Bortoletto, D.; Boswell, C.; Boulos, T.; Brandenburg, G.; Buckley-Geer, E.; Budd, H.S.; Burkett, K.; Busetto, G.; Byon-Wagner, A.; Byrum, K.L.; Campagnari, C.; Campbell, M.; Caner, A.; Carithers, W.; Carlsmith, D.; Castro, A.; Cen, Y.; Cervelli, F.; Chapman, J.; Chiarelli, G.; Chikamatsu, T.; Cihangir, S.; Clark, A.G.; Cobal, M.; Contreras, M.; Cooper, J.; Cordelli, M.; Coupal, D.P.; Crane, D.; Cunningham, J.D.; Daniels, T.; DeJongh, F.; Dell'Agnello, S.; Dell'Orso, M.; Demortier, L.; Denby, B.; Deninno, M.; Derwent, P.F.; Devlin, T.; Dickson, M.; Donati, S.; Done, J.P.; Drucker, R.B.; Dunn, A.; Einsweiler, K.; Elias, J.E.; Ely, R.; Engels, E. Jr.; Eno, S.; Errede, D.; Errede, S.; Etchegoyen, A.; Fan, Q.; Farhat, B.; Fiori, I.; Flaugher, B.; Foster, G.W.; Franklin, M.; Frautschi, M.; Freeman, J.; Friedman, J.; Frisch, H.; Fry, A.; Fuess, T.A.; Fukui, Y.; Funaki, S.; Gagliardi, G.; Gallinaro, M.; Garfinkel, A.F.; Geer, S.; Gerdes, D.W.; Giannetti, P.; Giokaris, N.; Giromini, P.; Gladney, L.; Glenzinski, D.; Gold, M.; Gonzalez, J.; Gordon, A.; Goshaw, A.T.; Goulianos, K.; Grassmann, H.; Grewal, A.; Grieco, G.; Groer, L.; Grosso-Pilcher, C.; Haber, C.; Hahn, S.R.; Hamilton, R.; Handler, R.; Hans, R.M.; Hara, K.; Harral, B.; Harris, R.M.; Hauger, S.A.; Hauser, J.; Hawk, C.; Heinrich, J.; Hennessy, D.; Hollebeek, R.; Holloway, L.; Hoelscher, A.; Hong, S.; Houk, G.; Hu, P.; Huffman, B.T.; Hughes, R.; Hurst, P.; Huston, J.; Huth, J.

1994-01-01

The lifetimes of the B + and B 0 mesons have been measured using fully reconstructed decays. In a sample of ∼49 600J/ψ→μ + μ - decays recorded with the Collider Detector at Fermilab, 148±16 B + and 121±16B 0 mesons have been reconstructed using the silicon vertex detector. Unbinned likelihood fits to the proper lifetime distributions of these B mesons give τ + =1.61±0.16 (stat)±0.05 (syst) ps, τ 0 =1.57±0.18 (stat) ±0.08 (syst) ps, and τ + /τ 0 =1.02±0.16 (stat) ±0.05 (syst)

Electromagnetic properties and sizes of new vector mesons within the three-triplet model

International Nuclear Information System (INIS)

Govorkov, A.B.

1976-01-01

The new vector mesons psi(3095) and psi'(3684) are treated by analogy with the ω- and PHI-mesons, respectively, within the scheme of three triplets of the integer charge quarks-sakations. Their decay into the lepton pairs is calculated in the model of nonrelativistic harmonic oscillator. It appears that sizes of the new mesons decrease, and the effective mass of constituent quarks increases as compared with the corresponding quantities of the usual mesons. Within the vector meson dominence model the relation between the width of the transition psi → ν+γ and photoproduction cross section on nucleons is established and the estimate for the former is 3 keV

Relativistic mean-field approximation with density-dependent screening meson masses in nuclear matter

International Nuclear Information System (INIS)

Sun, Baoxi; Lu, Xiaofu; Shen, Pengnian; Zhao, Enguang

2003-01-01

The Debye screening masses of the σ, ω and neutral ρ mesons and the photon are calculated in the relativistic mean-field approximation. As the density of the nucleon increases, all the screening masses of mesons increase. A different result with Brown–Rho scaling is shown, which implies a reduction in the mass of all the mesons in the nuclear matter, except the pion. Replacing the masses of the mesons with their corresponding screening masses in the Walecka-1 model, five saturation properties of the nuclear matter are fixed reasonably, and then a density-dependent relativistic mean-field model is proposed without introducing the nonlinear self-coupling terms of mesons. (author)

Techniques in meson spectroscopy

International Nuclear Information System (INIS)

Longacre, R.S.

1991-01-01

This report contains lectures on the following topics: the quark model and beyond using quantum chromodynamics; analysis of formation reactions; energy dependence of the partial wave amplitudes; where the data for the t-matrix analysis comes from; and coupled channel analysis of isoscalar mesons

Modification of the omega-meson lifetime in nuclear matter

NARCIS (Netherlands)

Kotulla, M.; Trnka, D.; Muehlich, P.; Anton, G.; Bacelar, J. C. S.; Bartholomy, O.; Bayadilov, D.; Beloglazov, Y. A.; Bogendoerfer, R.; Castelijns, R.; Crede, V.; Dutz, H.; Ehmanns, A.; Elsner, D.; Ewald, R.; Fabry, I.; Fuchs, M.; Essig, K.; Funke, Ch.; Gothe, R.; Gregor, R.; Gridnev, A. B.; Gutz, E.; Hoeffgen, S.; Hoffmeister, P.; Horn, I.; Hoessl, J.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Klein, Frank; Klein, Fritz; Klempt, E.; Konrad, M.; Kopf, B.; Krusche, B.; Langheinrich, J.; Loehner, H.; Lopatin, I. V.; Lotz, J.; Lugert, S.; Menze, D.; Messchendorp, J. G.; Mertens, T.; Metag, V.; Mosel, U.; Nanova, M.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Radkov, A.; Schadmand, S.; Schmidt, Ch.; Schmieden, H.; Schoch, B.; Shende, S.; Suft, G.; Sumachev, V. V.; Szczepanek, T.; Suele, A.; Thoma, U.; Varma, R.; Walther, D.; Weinheimer, Ch.; Wendel, Ch.

2008-01-01

Information on hadron properties in the nuclear medium has been derived from the photoproduction of omega mesons on the nuclei C, Ca, Nb, and Pb using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the omega-meson cross section on the nuclear mass

πη pair hard electroproduction and exotic hybrid mesons

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2005-01-01

We show that hard electroproduction is a promising way to study exotic hybrid mesons, in particular through the hybrid decay channel H->πη. We discuss the πη generalized distribution amplitude, calculate the production amplitude and propose a forward-backward asymmetry as a signal for the hybrid meson production

{pi}{eta} pair hard electroproduction and exotic hybrid mesons

Energy Technology Data Exchange (ETDEWEB)

Anikin, I.V. [LPT, Universite Paris-Sud, 91405-Orsay, France, UMR 8627 du CNRS (France); BLTP, JINR, 141980 Dubna (Russian Federation); CPHT, Ecole Polytechnique, 91128 Palaiseau, France, UMR 7644 du CNRS (France); Pire, B. [CPHT, Ecole Polytechnique, 91128 Palaiseau, France, UMR 7644 du CNRS (France); Szymanowski, L. [Soltan Institute for Nuclear Studies, Warsaw (Poland) and Univ. de Liege, B-4000 Liege (Belgium); Teryaev, O.V. [BLTP, JINR, 141980 Dubna (Russian Federation); Wallon, S. [LPT, Universite Paris-Sud, 91405-Orsay, France, UMR 8627 du CNRS (France)

2005-06-13

We show that hard electroproduction is a promising way to study exotic hybrid mesons, in particular through the hybrid decay channel H->{pi}{eta}. We discuss the {pi}{eta} generalized distribution amplitude, calculate the production amplitude and propose a forward-backward asymmetry as a signal for the hybrid meson production.

Mesonic Form Factors

Energy Technology Data Exchange (ETDEWEB)

Frederic D. R. Bonnet; Robert G. Edwards; George T. Fleming; Randal Lewis; David Richards

2003-07-22

We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors.

Mass and scattering length inequalities in QCD and QCD-like theories

International Nuclear Information System (INIS)

Nussinov, S.; Pennsylvania Univ., Philadelphia; Sathiapalan, B.

1985-01-01

Some observations about mass scattering length inequalities in QCD-like theories are presented. It is shown that the Weingarten mass inequality can be used to argue that global vector symmetries are unbroken in such theories. For QCD, in the limit Nsub(c)->infinite, it is shown that Msub(baryon)>=1/2Nsub(c)Msub(meson), provided there are at least Nsub(c) degenerate flavors of quarks. It is argued that when there are not bound states in a scattering channel, the mass inequalities can be used to derive inequalities beteen scattering lengths. Some rigorous inequalities for two and higher point functions for operators bilinear in currents are derived, and used to extract inequalities between quartic coupling constants. (orig.)

Decays of open charmed mesons in the extended Linear Sigma Model

Directory of Open Access Journals (Sweden)

Eshraim Walaa I.

2014-01-01

Full Text Available We enlarge the so-called extended linear Sigma model (eLSM by including the charm quark according to the global U(4r × U(4l chiral symmetry. In the eLSM, besides scalar and pseudoscalar mesons, also vector and axial-vector mesons are present. Almost all the parameters of the model were fixed in a previous study of mesons below 2 GeV. In the extension to the four-flavor case, only three additional parameters (all of them related to the bare mass of the charm quark appear.We compute the (OZI dominant strong decays of open charmed mesons. The results are compatible with the experimental data, although the theoretical uncertainties are still large.

Spectroscopy of pseudoscalar and vector mesons and their electroweak decays

International Nuclear Information System (INIS)

Ablakulov, Kh.

1997-01-01

Proceeding from the effective action of QCD for bilocal meson fields the formula for the action describing the spectroscopy of mesons and their electroweak decays is obtained. The numerical solutions of the Salpeter equation (SE) for the qq-bound state and the Schwinger-Dyson equation (SDE) for the quark phase function are obtained with potential as sum of the oscillator and Coulomb terms. It is shown that for the oscillator potential and current quark mass m 0 0 → γγ) are 3-4 times smaller than their experimentations. This discrepancy was not removed even choosing other shapes of the potential. In order to resolve this problem the modification of the SDE, which consists in introducing the additional terms that do not change asymptotical properties of solutions of this equation is proposed. Using such modification both constant fπ and Γ(π 0 → γγ) are reproduced on a good quantitative level. The new SE for vector mesons is proposed and its solution with potential mentioned above gives the mass spectra of these mesons. Considering the τ → ρν decay the representation for leptonic decay constant of ρ meson f π , which expresses via solutions of the SDE and the proposed SE with a given potential is obtained. It is shown that the proposed SE allows to describe both the spectroscopy of vector mesons and their leptonic decay constants on a satisfactory level in comparison with the experimental values. (author)

Hybrid mesons (Q anti Qg) in N anti N annihilation

International Nuclear Information System (INIS)

Dover, C.B.; Gutsche, T.; Faessler, A.

1993-09-01

N anti N annihilation reactions provide exciting possibilities to study mesonic resonances beyond the usual Q anti Q spectrum. Particularly the search for Q anti Qg mesons containing an explicit dynamical excitation of the gluon field is not promising, since hybrids are predicted to display unique features: exotic quantum numbers (J πC ) and dynamical selection rules for their decay modes. The authors have investigated the possibility of producing hybrids from p anti p atomic states in reactions of the type N anti N(L= 0,1) → π + Q anti Qg. Production rates for hybrid mesons are found to display a strong dependence on the quantum numbers and kinematical factors associated with the transition. The dependence on the orbital angular momentum L of the p anti p atomic state, accessible in p anti p annihilation at rest, would provide a striking signature for the production of hybrids. In estimating branching ratios for the formation of Q anti Qg hybrid mesons in N anti N annihilation reactions at rest, the authors have employed a microscopic model with constituent quarks and gluons in analogy to the annihilation model for the production of Q anti Q mesons

Deuteron threshold electrodisintegration at high momentum transfer

International Nuclear Information System (INIS)

Schmitt, W.M.; Turchinetz, W.; Williamson, C.F.

1997-01-01

Absolute differential cross sections for the threshold electrodisintegration of the deuteron with good resolution were measured at a laboratory scattering angle of 160 degree for five values of Q 2 ranging from 8.66 to 42.4 fm -2 . Comparisons of the data averaged over E np from 0--3 MeV and 0--10 MeV are made with nonrelativistic meson-exchange calculations. These calculations are sensitive to the nucleon electromagnetic form factors, nucleon-nucleon potential, and relativistic effects. The data are also compared with a hybrid quark-hadron model calculation that describes the deuteron as a six-quark cluster for the short range part of the interaction. Some of these calculations can describe the data reasonably well over certain ranges of Q 2 ; however, none of these calculations can accurately describe the data over the entire measured Q 2 range

Improved measurement of the B 0 and B + meson lifetimes

Science.gov (United States)

Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J. P.; Lucotte, A.; Minard, M. N.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Juste, A.; Martinez, M.; Orteu, S.; Pacheco, A.; Padilla, C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Palla, F.; Pater, J. R.; Pusztaszeri, J. F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Wildish, T.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J. M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Rensch, B.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Williams, M. I.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H. G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H. G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; St. Denis, R.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J. F.; Heusse, Ph.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A. M.; Nikolic, I.; Park, H. J.; Park, I. C.; Schune, M. H.; Simion, S.; Veillet, J. J.; Videau, I.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J. F.; Roussarie, A.; Schuller, J. P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Büscher, V.; Cowan, G.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Bellantoni, L.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Harton, J. L.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I. J.; Sharma, V.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.

1996-03-01

The lifetimes of the B 0 and B + mesons have been measured with the Aleph detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991 1994. In the first of three methods, semileptonic decays of B 0 and B + mesons were partially reconstructed by identifying events containing a lepton with an associated D*- orbar D^0 meson. The second method used fully reconstructed B 0 and B + mesons. The third method, used to measure the B 0 lifetime, employed a partial reconstruction technique to identify B 0→ D*- π + X decays. The combined results are begin{gathered} tau _0 = 1.55 ± 0.06 ± 0.03 ps, \\ tau _ + = 1.58 ± 0.09 ± 0.03 ps, \\ tfrac{{tau _ + }}{{tau _0 }} = 1.03 ± 0.08 ± 0.02. \\ .

Heavy quarks fragmentation in charmed mesons in DELPHI experiment at LEP

International Nuclear Information System (INIS)

Levy, J.M.

1994-04-01

With the big statistics expected at LEP, the electroweak sector of the Standard Model can be tested as well as the theory of strong interactions. Quantum Chromo-Dynamics is indeed predictive for quarks properties, but does not explain how quarks fragment into hadrons. So far the hadronization can only be described with phenomenological models. The work presented in this thesis was performed on the DELPHI experiment at LEP and concerns the production and the fragmentation of heavy quarks into charmed mesons D , D* and D**. With the whole statistics of 1991 and 1992 (1 013 300 hadronic decays of the Z), more than 4500 charmed mesons decays have been reconstructed in the channels D 0 → K - π + , D + → K - π + π+ and D * +→ D 0 π + followed by D 0 → K - π + . Using also 1993 data and the channel D 0 → K - π + π + π - , evidence for D** production is presented. For the first time, the production rate is measured for each D meson separately for cc and bb contributions. In fact, D mesons can be produced either directly from the fragmentation of c quark or un-directly from the fragmentation of b quark into B mesons which decay into D mesons. (authors). 120 refs

Effects of renormalizing the chiral SU(2) quark-meson model

Science.gov (United States)

Zacchi, Andreas; Schaffner-Bielich, Jürgen

2018-04-01

We investigate the restoration of chiral symmetry at finite temperature in the SU(2) quark-meson model, where the mean field approximation is compared to the renormalized version for quarks and mesons. In a combined approach at finite temperature, all the renormalized versions show a crossover transition. The inclusion of different renormalization scales leave the order parameter and the mass spectra nearly untouched but strongly influence the thermodynamics at low temperatures and around the phase transition. We find unphysical results for the renormalized version of mesons and the combined one.

Chiral symmetry breaking and the spin content of the ρ and ρ‧ mesons

Science.gov (United States)

Glozman, L. Ya.; Lang, C. B.; Limmer, M.

2011-11-01

Using interpolators with different SU(2)L × SU(2)R transformation properties we study the chiral symmetry and spin contents of the ρ and ρ‧ mesons in lattice simulations with dynamical quarks. A ratio of couplings of the qbarγi τq and qbarσ0i τq interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of ∼ 1 fm. In the ground state ρ meson the chiral symmetry is strongly broken with comparable contributions of both the (0 , 1) + (1 , 0) and (1 / 2 , 1 / 2) b chiral representations with the former being the leading contribution. In contrast, in the ρ‧ meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1 / 2 , 1 / 2) b. Using a unitary transformation from the chiral basis to the LJ2S+1 basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The ρ meson is practically a 3S1 state with no obvious trace of a "spin crisis". The ρ‧ meson has a sizeable contribution of the 3D1 wave, which implies that the ρ‧ meson cannot be considered as a pure radial excitation of the ρ meson.

D mesons in asymmetric nuclear matter

International Nuclear Information System (INIS)

Mishra, Amruta; Mazumdar, Arindam

2009-01-01

We calculate the in-medium D and D meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The D and D mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states (Ψ ' ,χ c ,J/Ψ) to DD pairs in dense hadronic matter. The isospin asymmetry in the doublet D=(D 0 ,D + ) is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the D(D) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures

Perturbative QCD effects in heavy meson decays

International Nuclear Information System (INIS)

Szezepaniak, A.; Henley, E.M.

1991-01-01

The amplitude for the exclusive nonleptonic decay of a heavy meson into two light pseudoscalar mesons is analyzed using the factorization formalism of perturbative QCD for exclusive reactions at large momentum transfer. We calculate the form factor b → u transition and compare it to the old quark model calculation and the new one based on the light cone formulation of the full quark model wave function. The new results we obtain are smaller by a factor of 2 - 3 as compared to the old value. (orig.)

B-meson factories: Physics, machines and detectors

International Nuclear Information System (INIS)

Kolanoski, H.

1990-10-01

This report gives a short survey of the present status of B-meson factory plans and discussions at different laboratories. The physics motivation for an e + e - machine running with the highest possible luminosity in the Γ(4S) energy region is outlined emphasizing the possibility to observe CP violation in the B-meson system. The technical concepts for such machines together with the basic luminosity limitations are discussed. Finally, the requirements on a detector which is able to cover the rich physics program are presented. (orig.)

The static-light meson spectrum from twisted mass lattice QCD

International Nuclear Information System (INIS)

Jansen, Karl; Michael, Chris; Shindler, Andrea; Wagner, Marc

2008-10-01

We compute the static-light meson spectrum with N f =2 flavours of sea quarks using Wilson twisted mass lattice QCD. We consider five different values for the light quark mass corresponding to 300 MeV PS s mesons. (orig.)

Radiative transitions in mesons within a non relativistic quark model

International Nuclear Information System (INIS)

Bonnaz, R.; Silvestre-Brac, B.; Gignoux, C.

2002-01-01

An exhaustive study of radiative transitions in mesons is performed in a non relativistic quark model. Three different types of mesons wave functions are tested. The effect of some usual approximations is commented. Overall agreement with experimental data is obtained

Meson radiobiology and therapy

International Nuclear Information System (INIS)

Kilgerman, M.M.

1975-08-01

High-linear energy transfer radiation (neutrons, heavy ions, and pions) have a greater relative biological effectiveness than low-linear energy transfer radiation by depositing a high density of ionization in irradiated cells. This overcomes the protective effect of oxygen; decreases the variation in sensitivity among the several stages of the cell cycles; and, inhibits the repair of sublethal damage as compared to x-rays, gamma rays, electrons and protons. Negative pi mesons (pions), appear particularly suited for radiation therapy as their penetration and depth-dose profiles lend themselves to shaping the high dose area to the tumor size and location. Preliminary biological experiments with pions produced at the Los Alamos Meson Physics Facility studied cell survival at various radiation depths and cell cycle sensitivity. Histologic study of data from the first human experiments indicated severe tumor cell destruction by pions as compared to x-rays in treating malignant melanoma skin nodules, without increased effects on dermal elements. (U.S.)

On rescattering in meson coherent photoproduction on nuclei

International Nuclear Information System (INIS)

Starkov, N.I.; Tsarev, V.A.

1978-01-01

Screening corrections for cross section of π deg-meson photoproduction on He nuclei were calculated: γ + 4 He → π 0 + 4 He. On the basis of the Glauber theory the effect of meson rescattering in the range of small transferred pulses (t) 2 and ''mean'' photon energies 2 2 ), determined by interference of members of one-and twofold interactions. The results are compared with those obtained by other authors

On meson resonances and chiral symmetry

International Nuclear Information System (INIS)

Lutz, M.F.M.

2003-07-01

We study meson resonances with quantum numbers J P = 1 + in terms of the chiral SU(3) Lagrangian. At leading order a parameter-free prediction is obtained for the scattering of Goldstone bosons off vector mesons with J P = 1 - once we insist on approximate crossing symmetry of the unitarized scattering amplitude. A resonance spectrum arises that is remarkably close to the empirical pattern. In particular, we find that the strangeness-zero resonances h 1 (1380), f 1 (1285) and b 1 (1235) are formed due to strong K anti K μ and K K μ channels. This leads to large coupling constants of those resonances to the latter states. (orig.)

Dipole moments of the rho meson

International Nuclear Information System (INIS)

Hecht, M.B.; McKellar, B.H.P.

1997-04-01

The electric and magnetic dipole moments (EDM) of the rho meson are calculated using the propagators and vertices derived from the quantum chromodynamics Dyson-Schwinger equations. Results obtained from using the Bethe-Salpeter amplitude studied by Chappell, Mitchell et. al., and Pichowsky and Lee, are compared. The rho meson EDM is generated through the inclusion of a quark electric dipole moment, which is left as a free variable. These results are compared to the perturbative results to obtain a measure of the effects of quark interactions and confinement. The two dipole moments are also calculated using the phenomenological MIT bag model to provide a further basis for comparison

Quarks and mesons in nuclei

International Nuclear Information System (INIS)

Rho, M.

1981-01-01

Quantum chromodynamics is believed to be candidate theory for the strong interactions and contains as its ingredients spinor quark fields and vector gluons, none of which can perhaps be ever liberated and detected in laboratories. A nucleus consists of nucleons bound by nuclear force which are however separately observable and which seem to preserve their identities even under extreme conditions. An intriguing question is: when compressed to high densities or heated to high temperature, at what point does a nuclear matter cease to be describable in terms of nucleon and meson degrees of freedom, but become a plasma of quarks and gluons; and how does this transition occur. This is not an idle question. If quarks and gluons are never to be observed isolated, then it may be that at low energies (or at low densities) they are not the right variables to do physics with. Instead hadrons must be. On the other hand, asymptotic freedom - the unique property of non-abelian gauge theories to which QCD belongs that quark-gluon and gluon-gluon interactions get weaker at short distances - tells us that at some large matter density the matter must necessarily be in the form of quark gas interacting only weakly. This means that a change in degrees of freedom must take place. We would like to know where this occurs and how. In this talk, I would like to address to this question by discussing first the large success we have had in understanding the role that mesons play in finite nuclei and nuclear matter and then attempting to correlate nucleon and meson degrees of freedom to quark-gluon degrees of freedom. In my opinion we are now at a stage where we feel fairly confident in our understanding of nucleon-meson structure of nuclei and nuclear matter and any further progress in deeper understanding of nuclear dynamics - and strong interactions - must come from QCD or its effective version, bags or strings. (orig.)

Brookhaven: Hunting for unusual mesons

Energy Technology Data Exchange (ETDEWEB)

Dzierba, Alex R.

1990-12-15

After the overwhelming experimental evidence for the quark model came the notions of colour and confinement which explained why quarks should prefer to bind in 'colourless' systems - quark-antiquark (mesons) and three quarks (baryons)

Role of Λ(1670) in the γp → K{sup +} ηΛ reaction near threshold

Energy Technology Data Exchange (ETDEWEB)

Xiao, Li-Ye; Zhong, Xian-Hui [Hunan normal University, Department of Physics, Hunan (China); Lue, Qi-Fang [Zhengzhou University, Department of Physics, Henan (China); Xie, Ju-Jun [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Institute of Modern Physics of CAS and Lanzhou University, Research Center for Hadron and CSR Physics, Lanzhou (China); Chinese Academy of Sciences, State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China)

2015-10-15

The role of the Λ(1670) resonance in the γp → K{sup +} ηΛ reaction near threshold is studied within an effective Lagrangian approach. We perform a calculation for the total and differential cross section of the γp → K{sup +} ηΛ reaction by including the contributions from the Λ(1670) intermediate state decaying into ηΛ dominated by K{sup -} and K{sup *-} mesons exchanges, the nucleon pole and N*(1535) resonance decaying into K{sup +} Λ dominated by exchanges of ω and K{sup -} mesons. Besides, the non-resonance process and contact terms to keep the total scattering amplitude gauge invariant are also considered. With our model parameters, the total cross section of this reaction is of the order of 1 nanobarn at photon beam energy E{sub γ} ∝ 2.5 GeV. It is expected that our model predictions could be tested by future experiments. (orig.)

Measurement of Charm Meson Lifetimes

International Nuclear Information System (INIS)

Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J.; Chan, S.; Eigen, G.; Lipeles, E.; Schmidtler, M.; Shapiro, A.; Sun, W.M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F.; Jaffe, D.E.; Masek, G.; Paar, H.P.; Potter, E.M.; Prell, S.; Sharma, V.; Asner, D.M.; Eppich, A.; Gronberg, J.; Hill, T.S.; Korte, C.M.; Lange, D.J.; Morrison, R.J.; Nelson, H.N.; Nelson, T.K.; Roberts, D.; Tajima, H.; Behrens, B.H.; Ford, W.T.; Gritsan, A.; Krieg, H.; Roy, J.; Smith, J.G.; Alexander, J.P.; Baker, R.; Bebek, C.; Berger, B.E.; Berkelman, K.; Boisvert, V.; Cassel, D.G.; Crowcroft, D.S.; Dickson, M.; Dombrowski, S. von; Drell, P.S.; Dumas, D.J.; Ecklund, K.M.; Ehrlich, R.; Foland, A.D.; Gaidarev, P.; Gibbons, L.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Hopman, P.I.; Katayama, N.; Kreinick, D.L.; Lee, T.; Liu, Y.; Meyer, T.O.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Thayer, J.G.; Thies, P.G.; Valant-Spaight, B.; Warburton, A.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Prescott, C.; Rubiera, A.I.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Ershov, A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Browder, T.E.; Li, Y.; Rodriguez, J.L.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D

1999-01-01

We report measurements of the D 0 , D + , and D + s meson lifetimes using 3.7 fb -1 of e + e - annihilation data collected near the Υ(4S) resonance with the CLEO detector. The measured lifetimes of the D 0 , D + , and D + s mesons are 408.5±4.1 +3.5 -3.4 fs , 1033.6±22.1 +9.9 -12.7 fs , and 486.3±15.0 +4.9 -5.1 fs . The precision of these lifetimes are comparable to those of the best previous measurements, and the systematic errors are very different. In a single experiment we find that the ratio of the D + s and D 0 lifetimes is 1.19±0.04 . copyright 1999 The American Physical Society

Nucleon and meson beams of the JINR phasotron for fundamental and applied investigations

International Nuclear Information System (INIS)

Abazov, V.M.; Andreev, G.A.; Bragin, A.N.

1990-01-01

The paper throughly describes the medical beam lines and reports the results obtained in measurement of the physical and dosimetric characteristics of high energy neutron, meson and proton beams obtained at the JINR phasotron in the last three years. It is pointed out that for the present intensity of the extracted proton beam of the JINR phasotron 2.0-2.5 μA the meson beam intensities 10 3 s- 1 (π + -mesons) and 3x10 7 s -1 (π - -mesons) have been achieved with a wide-angle magnetic lens. These values correspond to the designed parameters of the facility 'F' meson beams for the extracted proton beam intensity planned to be 25 μA. Besides, a beam of so-called 'surface μ-muons (energy about 4 MeV) with the intensity 10 4 s -1 has been obtained. The achieved meason beam intensities make the possibilities of the JINR phasotron as high as those of small meson factories with the equivalent extracted proton beam current 20-25 μA and ensures progress both in meson physics studies and in fulfilment of some applied tasks. 20 refs.; 7 figs.; 8 tabs

Meson production in two-photon interactions at LHC energies

Energy Technology Data Exchange (ETDEWEB)

Da Silva, D. T.; Goncalves, V. P.; Sauter, W. K. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Campus Universitario UFPel, CP 354, 96010-900, Capao do Leao-RS (Brazil)

2013-03-25

The LHC opens a new kinematical regime at high energy, where several questions related to the description of the high-energy regime of the Quantum Chromodynamics (QCD) remain without satisfactory answers. Some open questions are the search for non-q-bar q resonances, the determination of the spectrum of q-bar q states and the identification of states with anomalous {gamma}{gamma} couplings. A possible way to study these problems is the study of meson production in two-photon interactions. In this contribution we calculate the meson production in two-photon interactions at LHC energies considering proton - proton collisions and estimate the total cross section for the production of the mesons {pi}, a, f, {eta} and {chi}.

Measurement of Prompt D0 Meson Azimuthal Anisotropy in Pb-Pb Collisions at √{sN N }=5.02 TeV

Science.gov (United States)

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Grossmann, J.; Hrubec, J.; Jeitler, M.; König, A.; Krammer, N.; Krätschmer, I.; Liko, D.; Madlener, T.; Mikulec, I.; Pree, E.; Rabady, D.; Rad, N.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Spanring, M.; Spitzbart, D.; Waltenberger, W.; Wittmann, J.; Wulz, C.-E.; Zarucki, M.; Chekhovsky, V.; Mossolov, V.; Suarez Gonzalez, J.; De Wolf, E. A.; Di Croce, D.; Janssen, X.; Lauwers, J.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; De Bruyn, I.; De Clercq, J.; Deroover, K.; Flouris, G.; Lontkovskyi, D.; Lowette, S.; Moortgat, S.; Moreels, L.; Python, Q.; Skovpen, K.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Luetic, J.; Maerschalk, T.; Marinov, A.; Randle-conde, A.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Zhang, F.; Cimmino, A.; Cornelis, T.; Dobur, D.; Fagot, A.; Gul, M.; Khvastunov, I.; Poyraz, D.; Roskas, C.; Salva, S.; Tytgat, M.; Verbeke, W.; Zaganidis, N.; Bakhshiansohi, H.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; De Visscher, S.; Delaere, C.; Delcourt, M.; Francois, B.; Giammanco, A.; Jafari, A.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Musich, M.; Piotrzkowski, K.; Quertenmont, L.; Vidal Marono, M.; Wertz, S.; Beliy, N.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hensel, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Melo De Almeida, M.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Torres Da Silva De Araujo, F.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Misheva, M.; Rodozov, M.; Shopova, M.; Stoykova, S.; Sultanov, G.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Fang, W.; Gao, X.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Chen, Y.; Jiang, C. H.; Leggat, D.; Liao, H.; Liu, Z.; Romeo, F.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Yazgan, E.; Zhang, H.; Zhao, J.; Ban, Y.; Chen, G.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; González Hernández, C. F.; Ruiz Alvarez, J. D.; Courbon, B.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Sculac, T.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Ferencek, D.; Kadija, K.; Mesic, B.; Starodumov, A.; Susa, T.; Ather, M. W.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Finger, M.; Finger, M.; Carrera Jarrin, E.; El-khateeb, E.; Elgammal, S.; Ellithi Kamel, A.; Dewanjee, R. K.; Kadastik, M.; Perrini, L.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Faure, J. L.; Ferri, F.; Ganjour, S.; Ghosh, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Kucher, I.; Locci, E.; Machet, M.; Malcles, J.; Negro, G.; Rander, J.; Rosowsky, A.; Sahin, M. Ö.; Titov, M.; Abdulsalam, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Charlot, C.; Granier de Cassagnac, R.; Jo, M.; Lisniak, S.; Lobanov, A.; Martin Blanco, J.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Stahl Leiton, A. G.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Zghiche, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Jansová, M.; Le Bihan, A.-C.; Tonon, N.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Finco, L.; Gascon, S.; Gouzevitch, M.; Grenier, G.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Popov, A.; Sordini, V.; Vander Donckt, M.; Viret, S.; Khvedelidze, A.; Bagaturia, I.; Autermann, C.; Beranek, S.; Feld, L.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Preuten, M.; Schomakers, C.; Schulz, J.; Verlage, T.; Albert, A.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hamer, M.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Knutzen, S.; Merschmeyer, M.; Meyer, A.; Millet, P.; Mukherjee, S.; Olschewski, M.; Padeken, K.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Teyssier, D.; Thüer, S.; Flügge, G.; Kargoll, B.; Kress, T.; Künsken, A.; Lingemann, J.; Müller, T.; Nehrkorn, A.; Nowack, A.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Arndt, T.; Asawatangtrakuldee, C.; Beernaert, K.; Behnke, O.; Behrens, U.; Bermúdez Martínez, A.; Bin Anuar, A. A.; Borras, K.; Botta, V.; Campbell, A.; Connor, P.; Contreras-Campana, C.; Costanza, F.; Diez Pardos, C.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Eren, E.; Gallo, E.; Garay Garcia, J.; Geiser, A.; Gizhko, A.; Grados Luyando, J. M.; Grohsjean, A.; Gunnellini, P.; Harb, A.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Kasemann, M.; Keaveney, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Lelek, A.; Lenz, T.; Leonard, J.; Lipka, K.; Lohmann, W.; Mankel, R.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Ntomari, E.; Pitzl, D.; Raspereza, A.; Roland, B.; Savitskyi, M.; Saxena, P.; Shevchenko, R.; Spannagel, S.; Stefaniuk, N.; Van Onsem, G. P.; Walsh, R.; Wen, Y.; Wichmann, K.; Wissing, C.; Zenaiev, O.; Bein, S.; Blobel, V.; Centis Vignali, M.; Dreyer, T.; Garutti, E.; Gonzalez, D.; Haller, J.; Hinzmann, A.; Hoffmann, M.; Karavdina, A.; Klanner, R.; Kogler, R.; Kovalchuk, N.; Kurz, S.; Lapsien, T.; Marchesini, I.; Marconi, D.; Meyer, M.; Niedziela, M.; Nowatschin, D.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Scharf, C.; Schleper, P.; Schmidt, A.; Schumann, S.; Schwandt, J.; Sonneveld, J.; Stadie, H.; Steinbrück, G.; Stober, F. M.; Stöver, M.; Tholen, H.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Vormwald, B.; Akbiyik, M.; Barth, C.; Baur, S.; Butz, E.; Caspart, R.; Chwalek, T.; Colombo, F.; De Boer, W.; Dierlamm, A.; Freund, B.; Friese, R.; Giffels, M.; Gilbert, A.; Haitz, D.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Kassel, F.; Kudella, S.; Mildner, H.; Mozer, M. U.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Schröder, M.; Shvetsov, I.; Sieber, G.; Simonis, H. J.; Ulrich, R.; Wayand, S.; Weber, M.; Weiler, T.; Williamson, S.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Topsis-Giotis, I.; Karathanasis, G.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Evangelou, I.; Foudas, C.; Kokkas, P.; Mallios, S.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Strologas, J.; Triantis, F. A.; Csanad, M.; Filipovic, N.; Pasztor, G.; Bencze, G.; Hajdu, C.; Horvath, D.; Hunyadi, Á.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Makovec, A.; Molnar, J.; Szillasi, Z.; Bartók, M.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Choudhury, S.; Komaragiri, J. R.; Bahinipati, S.; Bhowmik, S.; Mal, P.; Mandal, K.; Nayak, A.; Sahoo, D. K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Chawla, R.; Dhingra, N.; Kalsi, A. K.; Kaur, A.; Kaur, M.; Kumar, R.; Kumari, P.; Mehta, A.; Singh, J. B.; Walia, G.; Kumar, Ashok; Shah, Aashaq; Bhardwaj, A.; Chauhan, S.; Choudhary, B. C.; Garg, R. 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M.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Caputo, C.; Colaleo, A.; Creanza, D.; Cristella, L.; De Filippis, N.; De Palma, M.; Errico, F.; Fiore, L.; Iaselli, G.; Lezki, S.; Maggi, G.; Maggi, M.; Miniello, G.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Ranieri, A.; Selvaggi, G.; Sharma, A.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Chhibra, S. S.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. 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T.; Ligabue, F.; Lomtadze, T.; Manca, E.; Mandorli, G.; Martini, L.; Messineo, A.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; Cipriani, M.; Daci, N.; Del Re, D.; Diemoz, M.; Gelli, S.; Longo, E.; Margaroli, F.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Preiato, F.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bartosik, N.; Bellan, R.; Biino, C.; Cartiglia, N.; Cenna, F.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Kiani, B.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Monteno, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Ravera, F.; Romero, A.; Ruspa, M.; Sacchi, R.; Shchelina, K.; Sola, V.; Solano, A.; Staiano, A.; Traczyk, P.; Belforte, S.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Zanetti, A.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Lee, J.; Lee, S.; Lee, S. W.; Moon, C. S.; Oh, Y. D.; Sekmen, S.; Son, D. C.; Yang, Y. C.; Lee, A.; Kim, H.; Moon, D. H.; Oh, G.; Brochero Cifuentes, J. A.; Goh, J.; Kim, T. J.; Cho, S.; Choi, S.; Go, Y.; Gyun, D.; Ha, S.; Hong, B.; Jo, Y.; Kim, Y.; Lee, K.; Lee, K. S.; Lee, S.; Lim, J.; Park, S. K.; Roh, Y.; Almond, J.; Kim, J.; Kim, J. S.; Lee, H.; Lee, K.; Nam, K.; Oh, S. B.; Radburn-Smith, B. C.; Seo, S. h.; Yang, U. K.; Yoo, H. D.; Yu, G. B.; Choi, M.; Kim, H.; Kim, J. H.; Lee, J. S. H.; Park, I. C.; Ryu, G.; Choi, Y.; Hwang, C.; Lee, J.; Yu, I.; Dudenas, V.; Juodagalvis, A.; Vaitkus, J.; Ahmed, I.; Ibrahim, Z. A.; Md Ali, M. A. B.; Mohamad Idris, F.; Wan Abdullah, W. A. T.; Yusli, M. N.; Zolkapli, Z.; Reyes-Almanza, R.; Ramirez-Sanchez, G.; Duran-Osuna, M. C.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-De La Cruz, I.; Rabadan-Trejo, R. I.; Lopez-Fernandez, R.; Mejia Guisao, J.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Oropeza Barrera, C.; Vazquez Valencia, F.; Pedraza, I.; Salazar Ibarguen, H. A.; Uribe Estrada, C.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Saddique, A.; Shah, M. A.; Shoaib, M.; Waqas, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Bunkowski, K.; Byszuk, A.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Pyskir, A.; Walczak, M.; Bargassa, P.; Beirão Da Cruz E Silva, C.; Calpas, B.; Di Francesco, A.; Faccioli, P.; Gallinaro, M.; Hollar, J.; Leonardo, N.; Lloret Iglesias, L.; Nemallapudi, M. V.; Seixas, J.; Toldaiev, O.; Vadruccio, D.; Varela, J.; Afanasiev, S.; Bunin, P.; Gavrilenko, M.; Golutvin, I.; Gorbunov, I.; Kamenev, A.; Karjavin, V.; Lanev, A.; Malakhov, A.; Matveev, V.; Palichik, V.; Perelygin, V.; Shmatov, S.; Shulha, S.; Skatchkov, N.; Smirnov, V.; Voytishin, N.; Zarubin, A.; Ivanov, Y.; Kim, V.; Kuznetsova, E.; Levchenko, P.; Murzin, V.; Oreshkin, V.; Smirnov, I.; Sulimov, V.; Uvarov, L.; Vavilov, S.; Vorobyev, A.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Karneyeu, A.; Kirsanov, M.; Krasnikov, N.; Pashenkov, A.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, I.; Safronov, G.; Spiridonov, A.; Stepennov, A.; Toms, M.; Vlasov, E.; Zhokin, A.; Aushev, T.; Bylinkin, A.; Chadeeva, M.; Parygin, P.; Philippov, D.; Polikarpov, S.; Popova, E.; Rusinov, V.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Terkulov, A.; Baskakov, A.; Belyaev, A.; Boos, E.; Ershov, A.; Gribushin, A.; Kaminskiy, A.; Kodolova, O.; Korotkikh, V.; Lokhtin, I.; Miagkov, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Snigirev, A.; Vardanyan, I.; Blinov, V.; Skovpen, Y.; Shtol, D.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Elumakhov, D.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Cirkovic, P.; Devetak, D.; Dordevic, M.; Milosevic, J.; Rekovic, V.; Alcaraz Maestre, J.; Barrio Luna, M.; Cerrada, M.; Colino, N.; De La Cruz, B.; Delgado Peris, A.; Escalante Del Valle, A.; Fernandez Bedoya, C.; Fernández Ramos, J. P.; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Pérez-Calero Yzquierdo, A.; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; Álvarez Fernández, A.; de Trocóniz, J. F.; Missiroli, M.; Moran, D.; Cuevas, J.; Erice, C.; Fernandez Menendez, J.; Gonzalez Caballero, I.; González Fernández, J. R.; Palencia Cortezon, E.; Sanchez Cruz, S.; Suárez Andrés, I.; Vischia, P.; Vizan Garcia, J. M.; Cabrillo, I. J.; Calderon, A.; Chazin Quero, B.; Curras, E.; Duarte Campderros, J.; Fernandez, M.; Garcia-Ferrero, J.; Gomez, G.; Lopez Virto, A.; Marco, J.; Martinez Rivero, C.; Martinez Ruiz del Arbol, P.; Matorras, F.; Piedra Gomez, J.; Rodrigo, T.; Ruiz-Jimeno, A.; Scodellaro, L.; Trevisani, N.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Auffray, E.; Baillon, P.; Ball, A. H.; Barney, D.; Bianco, M.; Bloch, P.; Bocci, A.; Botta, C.; Camporesi, T.; Castello, R.; Cepeda, M.; Cerminara, G.; Chapon, E.; Chen, Y.; d'Enterria, D.; Dabrowski, A.; Daponte, V.; David, A.; De Gruttola, M.; De Roeck, A.; Di Marco, E.; Dobson, M.; Dorney, B.; du Pree, T.; Dünser, M.; Dupont, N.; Elliott-Peisert, A.; Everaerts, P.; Franzoni, G.; Fulcher, J.; Funk, W.; Gigi, D.; Gill, K.; Glege, F.; Gulhan, D.; Gundacker, S.; Guthoff, M.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Karacheban, O.; Kieseler, J.; Kirschenmann, H.; Knünz, V.; Kornmayer, A.; Kortelainen, M. J.; Krammer, M.; Lange, C.; Lecoq, P.; Lourenço, C.; Lucchini, M. T.; Malgeri, L.; Mannelli, M.; Martelli, A.; Meijers, F.; Merlin, J. A.; Mersi, S.; Meschi, E.; Milenovic, P.; Moortgat, F.; Mulders, M.; Neugebauer, H.; Orfanelli, S.; Orsini, L.; Pape, L.; Perez, E.; Peruzzi, M.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pierini, M.; Racz, A.; Reis, T.; Rolandi, G.; Rovere, M.; Sakulin, H.; Schäfer, C.; Schwick, C.; Seidel, M.; Selvaggi, M.; Sharma, A.; Silva, P.; Sphicas, P.; Stakia, A.; Steggemann, J.; Stoye, M.; Tosi, M.; Treille, D.; Triossi, A.; Tsirou, A.; Veckalns, V.; Veres, G. I.; Verweij, M.; Wardle, N.; Zeuner, W. D.; Bertl, W.; Caminada, L.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Rohe, T.; Wiederkehr, S. A.; Bachmair, F.; Bäni, L.; Berger, P.; Bianchini, L.; Casal, B.; Dissertori, G.; Dittmar, M.; Donegà, M.; Grab, C.; Heidegger, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Klijnsma, T.; Lustermann, W.; Mangano, B.; Marionneau, M.; Meinhard, M. T.; Meister, D.; Micheli, F.; Musella, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pata, J.; Pauss, F.; Perrin, G.; Perrozzi, L.; Quittnat, M.; Reichmann, M.; Schönenberger, M.; Shchutska, L.; Tavolaro, V. R.; Theofilatos, K.; Vesterbacka Olsson, M. L.; Wallny, R.; Zhu, D. H.; Aarrestad, T. K.; Amsler, C.; Canelli, M. F.; De Cosa, A.; Del Burgo, R.; Donato, S.; Galloni, C.; Hreus, T.; Kilminster, B.; Ngadiuba, J.; Pinna, D.; Rauco, G.; Robmann, P.; Salerno, D.; Seitz, C.; Takahashi, Y.; Zucchetta, A.; Candelise, V.; Doan, T. H.; Jain, Sh.; Khurana, R.; Kuo, C. M.; Lin, W.; Pozdnyakov, A.; Yu, S. S.; Kumar, Arun; Chang, P.; Chao, Y.; Chen, K. F.; Chen, P. H.; Fiori, F.; Hou, W.-S.; Hsiung, Y.; Liu, Y. F.; Lu, R.-S.; Paganis, E.; Psallidas, A.; Steen, A.; Tsai, J. f.; Asavapibhop, B.; Kovitanggoon, K.; Singh, G.; Srimanobhas, N.; Adiguzel, A.; Boran, F.; Cerci, S.; Damarseckin, S.; Demiroglu, Z. S.; Dozen, C.; Dumanoglu, I.; Girgis, S.; Gokbulut, G.; Guler, Y.; Hos, I.; Kangal, E. 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R.; Williams, T.; Auzinger, G.; Bainbridge, R.; Breeze, S.; Buchmuller, O.; Bundock, A.; Casasso, S.; Citron, M.; Colling, D.; Corpe, L.; Dauncey, P.; Davies, G.; De Wit, A.; Della Negra, M.; Di Maria, R.; Elwood, A.; Haddad, Y.; Hall, G.; Iles, G.; James, T.; Lane, R.; Laner, C.; Lyons, L.; Magnan, A.-M.; Malik, S.; Mastrolorenzo, L.; Matsushita, T.; Nash, J.; Nikitenko, A.; Palladino, V.; Pesaresi, M.; Raymond, D. M.; Richards, A.; Rose, A.; Scott, E.; Seez, C.; Shtipliyski, A.; Summers, S.; Tapper, A.; Uchida, K.; Vazquez Acosta, M.; Virdee, T.; Winterbottom, D.; Wright, J.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Liu, H.; Pastika, N.; Smith, C.; Bartek, R.; Dominguez, A.; Buccilli, A.; Cooper, S. I.; Henderson, C.; Rumerio, P.; West, C.; Arcaro, D.; Avetisyan, A.; Bose, T.; Gastler, D.; Rankin, D.; Richardson, C.; Rohlf, J.; Sulak, L.; Zou, D.; Benelli, G.; Cutts, D.; Garabedian, A.; Hakala, J.; Heintz, U.; Hogan, J. M.; Kwok, K. H. M.; Laird, E.; Landsberg, G.; Mao, Z.; Narain, M.; Pazzini, J.; Piperov, S.; Sagir, S.; Syarif, R.; Yu, D.; Band, R.; Brainerd, C.; Burns, D.; Calderon De La Barca Sanchez, M.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Flores, C.; Funk, G.; Gardner, M.; Ko, W.; Lander, R.; Mclean, C.; Mulhearn, M.; Pellett, D.; Pilot, J.; Shalhout, S.; Shi, M.; Smith, J.; Squires, M.; Stolp, D.; Tos, K.; Tripathi, M.; Wang, Z.; Bachtis, M.; Bravo, C.; Cousins, R.; Dasgupta, A.; Florent, A.; Hauser, J.; Ignatenko, M.; Mccoll, N.; Saltzberg, D.; Schnaible, C.; Valuev, V.; Bouvier, E.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Ghiasi Shirazi, S. M. A.; Hanson, G.; Heilman, J.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Olmedo Negrete, M.; Paneva, M. I.; Shrinivas, A.; Si, W.; Wang, L.; Wei, H.; Wimpenny, S.; Yates, B. R.; Branson, J. G.; Cittolin, S.; Derdzinski, M.; Gerosa, R.; Hashemi, B.; Holzner, A.; Klein, D.; Kole, G.; Krutelyov, V.; Letts, J.; Macneill, I.; Masciovecchio, M.; Olivito, D.; Padhi, S.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Vartak, A.; Wasserbaech, S.; Wood, J.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Amin, N.; Bhandari, R.; Bradmiller-Feld, J.; Campagnari, C.; Dishaw, A.; Dutta, V.; Franco Sevilla, M.; George, C.; Golf, F.; Gouskos, L.; Gran, J.; Heller, R.; Incandela, J.; Mullin, S. D.; Ovcharova, A.; Qu, H.; Richman, J.; Stuart, D.; Suarez, I.; Yoo, J.; Anderson, D.; Bendavid, J.; Bornheim, A.; Lawhorn, J. M.; Newman, H. B.; Nguyen, T.; Pena, C.; Spiropulu, M.; Vlimant, J. R.; Xie, S.; Zhang, Z.; Zhu, R. Y.; Andrews, M. B.; Ferguson, T.; Mudholkar, T.; Paulini, M.; Russ, J.; Sun, M.; Vogel, H.; Vorobiev, I.; Weinberg, M.; Cumalat, J. P.; Ford, W. T.; Jensen, F.; Johnson, A.; Krohn, M.; Leontsinis, S.; Mulholland, T.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; Mcdermott, K.; Mirman, N.; Patterson, J. R.; Rinkevicius, A.; Ryd, A.; Skinnari, L.; Soffi, L.; Tan, S. M.; Tao, Z.; Thom, J.; Tucker, J.; Wittich, P.; Zientek, M.; Abdullin, S.; Albrow, M.; Apollinari, G.; Apresyan, A.; Apyan, A.; Banerjee, S.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Canepa, A.; Cerati, G. B.; Cheung, H. W. K.; Chlebana, F.; Cremonesi, M.; Duarte, J.; Elvira, V. D.; Freeman, J.; Gecse, Z.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Harris, R. M.; Hasegawa, S.; Hirschauer, J.; Hu, Z.; Jayatilaka, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Lammel, S.; Lincoln, D.; Lipton, R.; Liu, M.; Liu, T.; Lopes De Sá, R.; Lykken, J.; Maeshima, K.; Magini, N.; Marraffino, J. M.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mrenna, S.; Nahn, S.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Ristori, L.; Schneider, B.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Stoynev, S.; Strait, J.; Strobbe, N.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Wang, M.; Weber, H. A.; Whitbeck, A.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Brinkerhoff, A.; Carnes, A.; Carver, M.; Curry, D.; Field, R. D.; Furic, I. K.; Konigsberg, J.; Korytov, A.; Kotov, K.; Ma, P.; Matchev, K.; Mei, H.; Mitselmakher, G.; Rank, D.; Sperka, D.; Terentyev, N.; Thomas, L.; Wang, J.; Wang, S.; Yelton, J.; Joshi, Y. R.; Linn, S.; Markowitz, P.; Rodriguez, J. L.; Ackert, A.; Adams, T.; Askew, A.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Kolberg, T.; Martinez, G.; Perry, T.; Prosper, H.; Saha, A.; Santra, A.; Yohay, R.; Baarmand, M. M.; Bhopatkar, V.; Colafranceschi, S.; Hohlmann, M.; Noonan, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Cavanaugh, R.; Chen, X.; Evdokimov, O.; Gerber, C. E.; Hangal, D. A.; Hofman, D. J.; Jung, K.; Kamin, J.; Sandoval Gonzalez, I. D.; Tonjes, M. B.; Trauger, H.; Varelas, N.; Wang, H.; Wu, Z.; Zhang, J.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tiras, E.; Wetzel, J.; Yi, K.; Blumenfeld, B.; Cocoros, A.; Eminizer, N.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Roskes, J.; Sarica, U.; Swartz, M.; Xiao, M.; You, C.; Al-bataineh, A.; Baringer, P.; Bean, A.; Boren, S.; Bowen, J.; Castle, J.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Mcbrayer, W.; Murray, M.; Royon, C.; Sanders, S.; Schmitz, E.; Stringer, R.; Tapia Takaki, J. D.; Wang, Q.; Ivanov, A.; Kaadze, K.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Toda, S.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Calvert, B.; Eno, S. C.; Ferraioli, C.; Hadley, N. J.; Jabeen, S.; Jeng, G. Y.; Kellogg, R. G.; Kunkle, J.; Mignerey, A. C.; Ricci-Tam, F.; Shin, Y. H.; Skuja, A.; Tonwar, S. C.; Abercrombie, D.; Allen, B.; Azzolini, V.; Barbieri, R.; Baty, A.; Bi, R.; Brandt, S.; Busza, W.; Cali, I. A.; D'Alfonso, M.; Demiragli, Z.; Gomez Ceballos, G.; Goncharov, M.; Hsu, D.; Iiyama, Y.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Maier, B.; Marini, A. C.; Mcginn, C.; Mironov, C.; Narayanan, S.; Niu, X.; Paus, C.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Tatar, K.; Velicanu, D.; Wang, J.; Wang, T. W.; Wyslouch, B.; Benvenuti, A. C.; Chatterjee, R. M.; Evans, A.; Hansen, P.; Kalafut, S.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Gonzalez Suarez, R.; Kamalieddin, R.; Kravchenko, I.; Monroy, J.; Siado, J. E.; Snow, G. R.; Stieger, B.; Alyari, M.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alverson, G.; Barberis, E.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Teixeira De Lima, R.; Trocino, D.; Wood, D.; Bhattacharya, S.; Charaf, O.; Hahn, K. A.; Mucia, N.; Odell, N.; Pollack, B.; Schmitt, M. H.; Sung, K.; Trovato, M.; Velasco, M.; Dev, N.; Hildreth, M.; Hurtado Anampa, K.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Loukas, N.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Planer, M.; Reinsvold, A.; Ruchti, R.; Smith, G.; Taroni, S.; Wayne, M.; Wolf, M.; Woodard, A.; Alimena, J.; Antonelli, L.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Francis, B.; Hart, A.; Hill, C.; Ji, W.; Liu, B.; Luo, W.; Puigh, D.; Winer, B. L.; Wulsin, H. W.; Benaglia, A.; Cooperstein, S.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Higginbotham, S.; Lange, D.; Luo, J.; Marlow, D.; Mei, K.; Ojalvo, I.; Olsen, J.; Palmer, C.; Piroué, P.; Stickland, D.; Tully, C.; Malik, S.; Norberg, S.; Barker, A.; Barnes, V. E.; Das, S.; Folgueras, S.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, A. W.; Khatiwada, A.; Miller, D. H.; Neumeister, N.; Peng, C. C.; Qiu, H.; Schulte, J. F.; Sun, J.; Wang, F.; Xie, W.; Cheng, T.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Chen, Z.; Ecklund, K. M.; Geurts, F. J. M.; Guilbaud, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Roberts, J.; Rorie, J.; Tu, Z.; Zabel, J.; Bodek, A.; de Barbaro, P.; Demina, R.; Duh, Y. t.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Han, J.; Hindrichs, O.; Khukhunaishvili, A.; Lo, K. H.; Tan, P.; Verzetti, M.; Ciesielski, R.; Goulianos, K.; Mesropian, C.; Agapitos, A.; Chou, J. P.; Gershtein, Y.; Gómez Espinosa, T. A.; Halkiadakis, E.; Heindl, M.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Kyriacou, S.; Lath, A.; Montalvo, R.; Nash, K.; Osherson, M.; Saka, H.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Delannoy, A. G.; Foerster, M.; Heideman, J.; Riley, G.; Rose, K.; Spanier, S.; Thapa, K.; Bouhali, O.; Castaneda Hernandez, A.; Celik, A.; Dalchenko, M.; De Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Gilmore, J.; Huang, T.; Kamon, T.; Mueller, R.; Pakhotin, Y.; Patel, R.; Perloff, A.; Perniè, L.; Rathjens, D.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Damgov, J.; De Guio, F.; Dudero, P. R.; Faulkner, J.; Gurpinar, E.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Peltola, T.; Undleeb, S.; Volobouev, I.; Wang, Z.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Sheldon, P.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Barria, P.; Cox, B.; Hirosky, R.; Ledovskoy, A.; Li, H.; Neu, C.; Sinthuprasith, T.; Sun, X.; Wang, Y.; Wolfe, E.; Xia, F.; Harr, R.; Karchin, P. E.; Sturdy, J.; Zaleski, S.; Brodski, M.; Buchanan, J.; Caillol, C.; Dasu, S.; Dodd, L.; Duric, S.; Gomber, B.; Grothe, M.; Herndon, M.; Hervé, A.; Hussain, U.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Pierro, G. A.; Polese, G.; Ruggles, T.; Savin, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; CMS Collaboration

2018-05-01

The prompt D0 meson azimuthal anisotropy coefficients, v2 and v3, are measured at midrapidity (|y |N }=5.02 TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (pT ) range of 1 to 40 GeV /c , for central and midcentral collisions. The v2 coefficient is found to be positive throughout the pT range studied. The first measurement of the prompt D0 meson v3 coefficient is performed, and values up to 0.07 are observed for pT around 4 GeV /c . Compared to measurements of charged particles, a similar pT dependence, but smaller magnitude for pT <6 GeV /c , is found for prompt D0 meson v2 and v3 coefficients. The results are consistent with the presence of collective motion of charm quarks at low pT and a path length dependence of charm quark energy loss at high pT , thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark-gluon plasma.

Study of D(1285) → K+K-π0 decay and D(1285)- and E(1420)-mesons production in exclusive reactions, induced by π-- and K--mesons at 32.5 GeV/c

International Nuclear Information System (INIS)

Bitukov, S.I.; Viktorov, V.A.; Golovkin, S.V.

1985-01-01

D(1285) and E(1420)-mesons production in charge-exchange reactions induced by π - and K - -mesons at 32.5 GeV/c has been studied. The measured cross sections allowed one to derive limitations for the mixing angle in the axial-vector meson nonet. This means that E(1420)-meson consists mainly of strange quarks. The invariant mass distribution for the kaon pair in D(1285) → K + K - π 0 decay with statistics by an order of magnitude higher than the available data was obtained. The differential spectrum dN/dmsub(Ksup(+)Ksub(-)) analysis carried out in the delta-dominance model shows that delta(980)-meson cannot be described as a Breit-Wigner resonance with small width. The effective width for delta-meson at the point of √s=1 GeV/c 2 GITAsub(delta) is greater than 180 MeV/c 2 . It points to a strong coupling of delta-meson to hadrons

Angular Momentum Content of the ρ Meson in Lattice QCD

International Nuclear Information System (INIS)

Glozman, Leonid Ya.; Lang, C. B.; Limmer, Markus

2009-01-01

The variational method allows one to study the mixing of interpolators with different chiral transformation properties in the nonperturbatively determined physical state. It is then possible to define and calculate in a gauge-invariant manner the chiral as well as the partial wave content of the quark-antiquark component of a meson in the infrared, where mass is generated. Using a unitary transformation from the chiral basis to the 2S+1 L J basis one may extract a partial wave content of a meson. We present results for the ground state of the ρ meson using quenched simulations as well as simulations with n f =2 dynamical quarks, all for lattice spacings close to 0.15 fm. We point out that these results indicate a simple 3 S 1 -wave composition of the ρ meson in the infrared, like in the SU(6) flavor-spin quark model.

Angular Momentum Content of the ρ Meson in Lattice QCD

Science.gov (United States)

Glozman, Leonid Ya.; Lang, C. B.; Limmer, Markus

2009-09-01

The variational method allows one to study the mixing of interpolators with different chiral transformation properties in the nonperturbatively determined physical state. It is then possible to define and calculate in a gauge-invariant manner the chiral as well as the partial wave content of the quark-antiquark component of a meson in the infrared, where mass is generated. Using a unitary transformation from the chiral basis to the LJ2S+1 basis one may extract a partial wave content of a meson. We present results for the ground state of the ρ meson using quenched simulations as well as simulations with nf=2 dynamical quarks, all for lattice spacings close to 0.15 fm. We point out that these results indicate a simple S13-wave composition of the ρ meson in the infrared, like in the SU(6) flavor-spin quark model.

The anti pp yields anti λ λ reaction near threshold

International Nuclear Information System (INIS)

Maher, C.J.

1986-06-01

Measurements of differential and integrated cross sections as well as final state polarizations for the anti p p → anti Λ Λ reaction are presented. The reaction was studied at two incident antiproton momenta (1476.5 MeV/c and 1507.5 MeV/c) corresponding to total center of mass energies of 15.5 MeV and 26.4 MeV above the reaction threshold. The trajectories of charged decay products of the anti Λ and Λ were observed in a multiwire proportional chamber and in two sets of drift chambers. The data were analyzed with a computer program which reconstructed anti p p → anti Λ Λ → anti p π + pπ - events and performed kinematic fitting. The results are compared to several recent meson exchange calculations, and a one-gluon exchange calculation. The experiment was performed at the Low Energy Antiproton Ring (LEAR) at CERN. The data presented represent the first results of the PS185 collaboration's study of the threshold production of hyperon-antihyperon states

On the spin-parity of a E(1420) meson

International Nuclear Information System (INIS)

Asatryan, G.M.; Zaslavskij, A.N.

1977-01-01

The phenomenological analysis of data on the E(1420)-meson decay is carried out. The Adair distribution are constructed for the decays E→deltaπ, K* anti K(antiK*K), K anti K π, νππ in different reactions: the correlations in which the spin of E-meson is most explicitely manifested are marked

Covariant, chirally symmetric, confining model of mesons

International Nuclear Information System (INIS)

Gross, F.; Milana, J.

1991-01-01

We introduce a new model of mesons as quark-antiquark bound states. The model is covariant, confining, and chirally symmetric. Our equations give an analytic solution for a zero-mass pseudoscalar bound state in the case of exact chiral symmetry, and also reduce to the familiar, highly successful nonrelativistic linear potential models in the limit of heavy-quark mass and lightly bound systems. In this fashion we are constructing a unified description of all the mesons from the π through the Υ. Numerical solutions for other cases are also presented

Mesons from (non) Abelian T-dual backgrounds

Energy Technology Data Exchange (ETDEWEB)

Itsios, Georgios [Instituto de Física Teórica, UNESP-Universidade Estadual Paulista, R. Dr. Bento T. Ferraz 271, Bl. II, Sao Paulo 01140-070, SP (Brazil); Department of Physics, University of Oviedo,Avda. Calvo Sotelo 18, 33007 Oviedo (Spain); Núñez, Carlos [Department of Physics, Swansea University,Swansea SA2 8PP (United Kingdom); Zoakos, Dimitrios [Centro de Física do Porto, Universidade do Porto,Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

2017-01-03

In this work we study mesonic excitations in a Quantum Field Theory dual to the non Abelian T-dual of AdS{sub 5}×S{sup 5}, using a D6 brane probe on the Sfetsos-Thompson background. Before and after the duality, we observe interesting differences between the spectra and interpret them. The spectrum of masses and the interactions between mesonic excitations teach valuable lessons about the character of non-Abelian T-duality and its implications for Holography. The case of Abelian T-duality is also studied.

Meson wave functions in 2-dim QCD

International Nuclear Information System (INIS)

Hildebrandt, S.; Visnjic, V.

1977-07-01

We consider the eigenvalue problem of 't Hooft for the meson spectrum in 2-dim QCD by defining some alternative formulations whose equivalence we prove. Hence we are able to prove that the spectrum is discrete and of finite multiplicity and to derive bounds (upper and lower) for the eigenvalues (ground state, with state and n → infinitely state). We prove that the functions are analytic and use this to carry out explicit numerical calculations of the wave functions for various values of the quark masses and to recalculate the meson spectrum. (orig.) [de

Threshold current for fireball generation

Science.gov (United States)

Dijkhuis, Geert C.

1982-05-01

Fireball generation from a high-intensity circuit breaker arc is interpreted here as a quantum-mechanical phenomenon caused by severe cooling of electrode material evaporating from contact surfaces. According to the proposed mechanism, quantum effects appear in the arc plasma when the radius of one magnetic flux quantum inside solid electrode material has shrunk to one London penetration length. A formula derived for the threshold discharge current preceding fireball generation is found compatible with data reported by Silberg. This formula predicts linear scaling of the threshold current with the circuit breaker's electrode radius and concentration of conduction electrons.

Brookhaven: Hunting for unusual mesons

International Nuclear Information System (INIS)

Dzierba, Alex R.

1990-01-01

After the overwhelming experimental evidence for the quark model came the notions of colour and confinement which explained why quarks should prefer to bind in 'colourless' systems - quark-antiquark (mesons) and three quarks (baryons)

DS Mesons in Asymmetric Hot and Dense Hadronic Matter

Directory of Open Access Journals (Sweden)

Divakar Pathak

2015-01-01

Full Text Available The in-medium properties of DS mesons are investigated within the framework of an effective hadronic model, which is a generalization of a chiral SU(3 model, to SU(4, in order to study the interactions of the charmed hadrons. In the present work, the DS mesons are observed to experience net attractive interactions in a dense hadronic medium, hence reducing the masses of the DS+ and DS- mesons from the vacuum values. While this conclusion holds in both nuclear and hyperonic media, the magnitude of the mass drop is observed to intensify with the inclusion of strangeness in the medium. Additionally, in hyperonic medium, the mass degeneracy of the DS mesons is observed to be broken, due to opposite signs of the Weinberg-Tomozawa interaction term in the Lagrangian density. Along with the magnitude of the mass drops, the mass splitting between DS+ and DS- mesons is also observed to grow with an increase in baryonic density and strangeness content of the medium. However, all medium effects analyzed are found to be weakly dependent on isospin asymmetry and temperature. We discuss the possible implications emanating from this analysis, which are all expected to make a significant difference to observables in heavy ion collision experiments, especially the upcoming Compressed Baryonic Matter (CBM experiment at the future Facility for Antiproton and Ion Research (FAIR, GSI, where matter at high baryonic densities is planned to be produced.

Decay of heavy mesons into possible spin 3/2 leptons

International Nuclear Information System (INIS)

Carvalho, H.F. de; Antunes, A.C.B.

1982-01-01

The recent interest in the study of possible spin 3/2 leptons motivated our calculation of the decay rate of heavy mesons into these leptons. The mesons be upsilon UPSILON particles (bb sup(-) systems) or any other system of the qq sup(-) (quark-antiquark) kind with mass larger than those of the upsilon particles, for example, tt sup(-) bound states (not yet detected). The decay rate of these mesons is calculated as a function of the mass of the spin 3/2 leptons. The results obtained are compared with those of the spin 1/2 leptons. (Author) [pt

Scattering phaseshift formulas for mesons and baryons in elongated boxes

Science.gov (United States)

Lee, Frank X.; Alexandru, Andrei

2018-03-01

We derive Lüscher phaseshift formulas for two-particle states in boxes elongated in one of the dimensions. Such boxes offer a cost-effective way of varying the relative momentum of the particles. Boosted states in the elongated direction, which allow wider access to energies, are also considered. The formulas for the various scenarios (moving and zero-momentum states in cubic and elongated boxes) are compared and relations between them are clarified. The results are applicable to a wide set of meson-meson and meson-baryon elastic scattering processes, with the two-particle system having equal or unequal masses.

Semileptonic decays of strange beauty mesons at Belle

International Nuclear Information System (INIS)

Oswald, Christian

2015-01-01

Semileptonic decays of b-flavoured mesons are an important tool for the determination of the CKM matrix element vertical stroke V cb vertical stroke. In this thesis, measurements of semileptonic B s meson decays are presented. They provide complementary information to the precision measurements of B meson decays and serve as a test of QCD-calculations predicting SU(3) flavour symmetry for the partial decay widths and form factors. The semi-inclusive and inclusive analyses of semileptonic B s decays are based on the 121.4 fb -1 dataset collected by the Belle detector at the KEKB asymmetric-energy e + e - collider in Tsukuba, Japan. The sample recorded at a centre-of-mass energy √(s)=10.86 GeV, which corresponds to the Y(5S) resonance, contains (7.1±1.3) million B s pair events. To measure the semi-inclusive B s → D s Xlν and B s → D s * Xlν branching fractions, D s and D s * candidates are reconstructed and are paired with an oppositely charged lepton, l + =e + ,μ + . The yields of correctly reconstructed D s and D s * mesons are determined by fits to their respective invariant mass distributions. The signal yield and the yields of the remaining backgrounds are extracted using kinematic distributions of the reconstructed decay products and the constraint from the known initial state of the e + e - collision. The measured branching fractions are: B(B s → D s Xlν)=(8.2±0.2(stat)±0.6(syst)±1.4(ext)) % and B(B s → D s * lν)=(5.4±0.4(stat)±0.4(syst)±0.9 (ext)) %, where the first two uncertainties are the statistical and systematic uncertainties of the measurement and the last uncertainty is due to external parameters. Making an assumption about the B s → D s Xlν branching fraction, the measurement of the B s → D s Xlν yield is also used to obtain the current best estimate of the B s pair production cross-section at a centre-of-mass energy √(s)=10.86 GeV: σ(e + e - → B s pairs)=(57.1±1.5(stat)±4.3(syst)±4.2(ext)) pb. The semi

Threshold Characteristics of Slow-Light Photonic Crystal Lasers

DEFF Research Database (Denmark)

Xue, Weiqi; Yu, Yi; Ottaviano, Luisa

2016-01-01

The threshold properties of photonic crystal quantum dot lasers operating in the slow-light regime are investigated experimentally and theoretically. Measurements show that, in contrast to conventional lasers, the threshold gain attains a minimum value for a specific cavity length. The experimental...... results are explained by an analytical theory for the laser threshold that takes into account the effects of slow light and random disorder due to unavoidable fabrication imperfections. Longer lasers are found to operate deeper into the slow-light region, leading to a trade-off between slow-light induced...

SU(N)-QCD2 meson equation in next-to-leading order

International Nuclear Information System (INIS)

Durgut, M.; Pak, N.K.

1982-08-01

We compute the 1/N corrections to the meson equation in the regular cut-off scheme. We illustrate that although the quark and gluon self energy and vertex corrections do not vanish explicitly as in the singular cut-off scheme, their contributions to the meson Bethe-Salpeter equation get cancelled within the whole set of contributing diagrams. We also argue that 0(1/N) corrections to the meson equation remove the massless boson from the spectrum in accordance with the Coleman theorem. (author)

Heavy quarks fragmentation in charmed mesons in DELPHI experiment at LEP; Etude de la fragmentation des quarks lourds en mesons charmes dans l`experience Delphi au LEP

Energy Technology Data Exchange (ETDEWEB)

Levy, J.M.

1994-04-01

With the big statistics expected at LEP, the electroweak sector of the Standard Model can be tested as well as the theory of strong interactions. Quantum Chromo-Dynamics is indeed predictive for quarks properties, but does not explain how quarks fragment into hadrons. So far the hadronization can only be described with phenomenological models. The work presented in this thesis was performed on the DELPHI experiment at LEP and concerns the production and the fragmentation of heavy quarks into charmed mesons D , D* and D**. With the whole statistics of 1991 and 1992 (1 013 300 hadronic decays of the Z), more than 4500 charmed mesons decays have been reconstructed in the channels D{sup 0}{yields} K{sup -} {pi}{sup +} , D{sup +}{yields} K{sup -} {pi}{sup +}{pi}+ and D{sup *}+{yields} D{sup 0}{pi}{sup +} followed by D{sup 0}{yields} K{sup -}{pi}{sup +} . Using also 1993 data and the channel D{sup 0}{yields} K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} , evidence for D** production is presented. For the first time, the production rate is measured for each D meson separately for cc and bb contributions. In fact, D mesons can be produced either directly from the fragmentation of c quark or un-directly from the fragmentation of b quark into B mesons which decay into D mesons. (authors). 120 refs.

On a low energy, strong interaction model, unifying mesons and baryons

International Nuclear Information System (INIS)

Kalafatis, D.

1993-03-01

This thesis is concerned with the study of a unified theory of mesons and baryons. An effective Lagrangian with the low mass mesons, generalizing the Skyrme model, is constructed. The vector meson fields are introduced as gauge fields in the linear sigma model instead of the non linear sigma model. Topological soliton solutions of the model are examined and the nucleon-nucleon interaction in the product approximation is investigated. The leading correction to the classical skyrmion mass, the Casimir energy, is evaluated. The problem of the stability of topological solitons when vector fields enter the chiral Lagrangian is also studied. It is shown that the soliton is stable in very much the same way as with the ωmeson and that peculiar classical doublet solutions do not exist

Neutron stars in relativistic mean field theory with isovector scalar meson

International Nuclear Information System (INIS)

Kubis, S.; Kutschera, M.; Stachniewicz, S.

1998-01-01

We study the equation of state (EOS) of β-stable dense matter and models of neutron stars in the relativistic mean field (RMF) theory with the isovector scalar mean field corresponding to the δ-meson (a 0 (980)). A range of values of the δ-meson coupling compatible with the Bonn potentials is explored. Parameters of the model in the isovector sector are constrained to fit the nuclear symmetry energy, E s ∼30 MeV. We find that the quantity most sensitive to the δ-meson coupling is the proton fraction of neutron star matter. It increases significantly in the presence of the δ-field. The energy per baryon also increases but the effect is smaller. The EOS becomes slightly stiffer and the maximum neutron star mass increases for stronger δ-meson coupling. (author)

Improved measurement of the $\\overline{B}^{0}$ and B$^{-}$ meson lifetimes

CERN Document Server

Buskulic, Damir; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Alemany, R; Bazarko, A O; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Palla, Fabrizio; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Wildish, T; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Letho, M; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Büscher, V; Cowan, G D; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

1996-01-01

The lifetimes of the \\b0 \\ and \\bp\\ mesons have been measured with the \\aleph\\ detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991--1994. In the first of three methods, semileptonic decays of \\b0 \\ and \\bp\\ mesons were partially reconstructed by identifying events containing a lepton with an associated \\ds\\ or \\d0 \\ meson. The second method used fully reconstructed \\bz\\ and \\bp\\ mesons. The third method, used to measure the \\bz\\ lifetime, employed a partial reconstruction technique to identify \\bz\\to D^{*+}\\pi^- X decays. The combined results are \\begin{eqnarray*} \\t0 & = & 1.55\\pm 0.06\\pm 0.03 \\mathrm{\\ ps}, \\\\ \\tp & = & 1.58\\pm 0.09\\pm 0.03 \\mathrm{\\ ps}, \\\\ \\trat & = & 1.03\\pm 0.08\\pm 0.02.

Deuteron breakup in the 2H(e,e'p) reaction at low momentum transfer and close to threshold

International Nuclear Information System (INIS)

Neumann-Cosel, P. von; Richter, A.; Schrieder, G.; Shevchenko, A.; Stiller, A.; Arenhoevel, H.

2002-04-01

Deuteron breakup has been studied in a 2 H(e, e'p) coincidence experiment at low momentum transfer and for energies close to threshold. The longitudinal-plus-transverse (L + T) and longitudinal-transverse interference (LT) cross sections are deduced. Nonrelativistic calculations based on the Bonn potential and including leading order relativistic contributions, meson exchange currents and isobar configurations describe the (L + T) data well. Surprisingly large deviations of 30 to 45% are observed for the LT contribution. (orig.)

Observation of the weak time’s arrow in B mesons

CERN Multimedia

CERN. Geneva

2012-01-01

The mechanism of CP violation in weak interactions, as arising from the single physical phase in the CKM matrix, has been validated by more than a decade of intense experimental work probing CP violation, particularly with studies with B mesons. Since the Standard Model theory is CPT invariant, it predicts a “weak arrow of time” matching the large observed matter-antimatter asymmetry in B mesons. However, until recently there has been no direct observation of the expected, large time reversal (T) asymmetry. In this seminar we shall discuss how the BABAR experiment at SLAC has conducted a new data analysis where the decays of entangled neutral B mesons allow comparisons between the rates of four different transitions and their inverse, as a function of the time evolution of the B meson. The results lead to the first high significance, direct observation of T non-invariance through the exchange of initial and final states in transitions that can only be connected by a T symmetry transformation.

Effective mass of omega meson and NNω interaction at finite temperature and density

International Nuclear Information System (INIS)

Gao, S.; Su, R.; Yu, P.K.N.

1994-01-01

By means of the thermofield dynamical theory, the effective mass of omega meson is calculated by summing the bubble diagrams. It is found that the formula for the effective mass of the ρ meson can also be used to describe the ω meson in the low density region, but the parameter n and the critical temperature T c depend on the density. The temperature and density dependence of one omega exchage potential of nucleon-nucleon interaction are given. The conjecture of Brown and Rho about the effective masses of mesons is discussed

Beauty vector meson decay constants from QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Lucha, Wolfgang [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Melikhov, Dmitri [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); D. V. Skobeltsyn Institute of Nuclear Physics, M. V. Lomonosov Moscow State University, 119991, Moscow (Russian Federation); Simula, Silvano [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146, Roma (Italy)

2016-01-22

We present the outcomes of a very recent investigation of the decay constants of nonstrange and strange heavy-light beauty vector mesons, with special emphasis on the ratio of any such decay constant to the decay constant of the corresponding pseudoscalar meson, by means of Borel-transformed QCD sum rules. Our results suggest that both these ratios are below unity.

Meson exchange and neutral weak currents

Energy Technology Data Exchange (ETDEWEB)

Beck, D.H. [Univ. of Illinois, Urbana, IL (United States)

1994-04-01

Measurements of parity-violating electron scattering asymmetries to determine weak neutral currents in nuclei will be effected by the presence of meson exchange currents. Present low momentum transfer calculations, based on a flavor independent framework, show these effects to be small. In general, however, as the momentum transfer increases to values typical of deep-inelastic scattering, fragmentation functions show a clear flavor dependence. It is suggested that a good experimental starting point for understanding the flavor dependence of meson production and exchange currents is the Q{sup 2} dependence of parity-violating asymmetry in inclusive single pion electroproduction. A CEBAF facility with doubled energy is necessary to approach momentum transfers where this process begins to scale.

Quark-gluon plasma tomography by vector mesons

International Nuclear Information System (INIS)

Lovas, I.

2001-01-01

Full text: The most important aim of relativistic heavy ion experiments is the observation f the quark-gluon plasma formation. In order to detect the transition into the plasma state it is desirable to map the density profile of the fireball formed in the collision. Here we investigate the possibility of this mapping by tomography. The fireball is characterized by the impact parameter vector b, which can be determined from the multiplicity and the angular distribution of the reaction products. By appropriate rotations the b vectors of each collision can be aligned into a fixed direction. Using the measured values of the momentum distributions independent integral equations can be formulated for the unknown emission densities (EM(r) and for the unknown absorption densities (Δ μ M (r)) of the different vector mesons M(≡ ω 0 , ρ 0 , φ 0 , ψ 0 , ψ 0' , Υ). At a fixed value of M and b the number of detected mesons N M (p,b) with momentum p, can be expressed by the following formula: N M (p,b) = ∫ V(b) dr EM(r) exp[-μ M (p)L(r,p o )] V(b) R(r, po)] exp[- ∫ from r until R(r,p 0 ) dl ' Δ μ M (r ' ,p)], where the average value of the absorption coefficient having no r dependence is denoted by μ(p), while Δ μM is defined as Δ μM = μ M - μ- M . The meson arrives to the surface of the fireball at R(r, p 0 ). The length of the path between r and R is denoted by L(r, po). The equation given above can be considered as an integral equation. Unfortunately it can not be transformed into an exact system of linear equations. However an iterative procedure can be constructed in such a way that in every iterative step a linear system of equations must be solved. N M (p,b) = ∫ V(b) dr exp[- μ M (p) L(r,p o )] [E M n (r) Σ from k=O until (n-1) (1/k !) (- ∫ from r until R (r, p 0 ) dl ' Δ μM n-1 (r ' , p) k + E M n-1 (r) (1/n !) (- ∫ from r until R(r, p 0 ) dl ' Δ μM n-1 (r ' , p)) (n-1) (- ∫ from r until R(r, p 0 ) dl ' Δ μM (n) (r ' , p))]. Since

A phenomenological analysis of non-resonant charm meson decays

International Nuclear Information System (INIS)

Bediaga, I.; Goebel, C.; Mendez-Galain, R.

1997-07-01

We analyse the consequences of the usual assumption of a constant function to fit non-resonant decays from experimental Dalitz plot describing charmed meson decays. We first show, using the D + -> K 0 π + π 0 decay channel as an example, how an inadequate extraction of the non-resonant contribution could yield incorrect measurements for the resonant channels. We analyse how the correct study of this decay will provide a test for the validity of factorization in D meson decays. Finally, we show how form factors that can be measured from the D + s -> π - π + π + decay. We emphasize its relevance for the study of the decay τ -> v t 3π and the extraction of the α 1 meson width. (author)

General characteristics of Bc-mesons. Production mechanisms and decays

International Nuclear Information System (INIS)

Gershtein, S.S.; Likhoded, A.K.; Slabospitsky, S.R.

1989-01-01

Using Martin potential, independent of b- and c-quark flavour, the mass spectrum of B c (bc-bar)-mesons and widths of electromagnetic transition between them are calculated. The estimations of the production cross section at e + e - colliders, in hadronic and neutrino interactions are obtained. A real possibility to observed B c mesons at LEP and also at hadron colliders (σ(B c )/σ(bb-bar)∼10 -3 ) has been pointed out. The importance of observing the annihilation decay channels of B c -mesons: B c →τν τ (Br(B c →τν τ )=1.5-2%), and B c →ΦD s , B C →DK etc, has been emphasized. 25 refs.; 16 figs.; 5 tabs

Summary of Meson'98 Workshop

International Nuclear Information System (INIS)

Henley, E.M.

1998-01-01

One never quite knows what to say in a summary. If you were at the sessions, you heard the same talks I did. Perhaps the purpose is to summarize the parallel sessions, but like you, I can only attend one of these sessions. In addition, the time is short, so that this cannot be a real summary. What I will present are impressions of the past two days, and these will certainly be colored by my own views. Thus at the outset, let me apologize for any and all omissions and distortions. I will cover primarily the plenary session talks, but will organize this summary along the following lines: 1. vector (V) mesons; 2. pseudoscalar mesons, and 3. other subjects, notably with electrons. This afternoon's talks are so close in time to this summary that I shall omit them. (author)

Doubly charmed exotic mesons: A gift of nature?

Energy Technology Data Exchange (ETDEWEB)

Carames, T.F. [Departamento de Fisica Fundamental, Universidad de Salamanca, E-37008 Salamanca (Spain); Valcarce, A., E-mail: valcarce@usal.e [Departamento de Fisica Fundamental, Universidad de Salamanca, E-37008 Salamanca (Spain); Vijande, J. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Valencia (UV) and IFIC (UV-CSIC), Valencia (Spain)

2011-05-16

We study doubly charmed exotic states by solving the scattering problem of two D mesons. Our results point to the existence of a stable isoscalar doubly charmed meson with quantum numbers (I)J{sup P}=(0)1{sup +}. We perform a thorough comparison to the results obtained within the hyperspherical harmonic formalism. Such exotic states could be measured at LHC and RHIC. Their experimental observation would, for the first time, confirm the contribution of multiquark structures to hadron spectroscopy.

arXiv Measurement of the D-meson nuclear modification factor and elliptic flow in Pb-Pb collisions at $\\sqrt{s_{\\text{{NN}}}}$ = 5.02 TeV with ALICE at the LHC

CERN Document Server

Jaelani, Syaefudin

2018-05-03

Heavy-flavour hadrons are effective probes to study the Quark-Gluon Plasma (QGP) formed in ultra-relativistic heavy-ion collisions. The ALICE Collaboration measured the D-mesons (D0, D+, D*+ and Ds+) production in Pb–Pb collisions at sNN = 5.02 TeV. The in-medium energy loss can be studied by means of the nuclear modification factor (RAA). The comparison between the Ds+ and the non-strange D-meson RAA can help to study the hadronisation mechanism of the charm quark in the QGP. In semi-central collisions the measurement of the D-meson elliptic flow, v2, at low pT allows to investigate the participation of the heavy quarks in the collective expansion of the system while at high pT it constrains the path-length dependence of the energy loss. Furthermore the Event-Shape Engineering (ESE) technique is used to measure D-meson elliptic flow in order to study the coupling of the charm quarks to the light quarks of the underlying medium.

Study of the Bs meson and measurement of its half-life with the ALEPH detector

International Nuclear Information System (INIS)

Duarte, H.

1994-01-01

The B s 0 meson is the bound state of a quark anti-quark pair made up of a beauty particle and a strange particle. In the first chapter we review different experimental results leading to the existence of B S 0 meson and we draw the theoretical framework of the concept of beauty particles. The second chapter deals with the probability of the formation of a meson containing a strange quark during the fragmentation. This chapter also contains a re-analysis of the whole data constraining the mixing parameter B s 0 -B s 0 -bar. The relevancy of the analysis relies on the assumption that the B s 0 meson decays only into one D s , one lepton and one neutrino. The ALEPH detector is described in chapter 3, this four-pi, multi-particle detector is installed on the e + e - LEP (Large Electron Positron Collider). The signature selected for the measurement of the half-life is the combination of one D s in the decay modes: φπ, K *0 K with a lepton having opposite charge. This measurement implies the knowledge of the B s 0 momentum and of its flight length. In order to assess the momentum of the neutrino, a technique of measuring missing energy is presented in the chapter 4. The selection of B s 0 events is detailed in the chapter 5. A cutting limit on the energy of B s 0 based on the missing energy is used to deduce the production rate of B s 0 . In the chapter 6 we present the measurement of the half-life of B s 0 , the method used for the reconstruction of decay vertices and of the event main vertex is detailed. The validity of the method has been tested on Monte-Carlo simulations. The final result concerning the measurement of the half-life is: τ(B s )=[1.92(+0.45-0.35)±0.04] ps [fr

About absence of oscillations at CP violation and presence of interference between KS-, KL-meson states in the system of K0 mesons

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

2014-01-01

Two approaches to the description of K 0 -, K 0 -bar-meson transitions into K 1 0 mesons at CP violation in weak interactions are considered. The first approach uses the standard theory of oscillations and the second approach supposes that (K S , K L ) states which arise at CP violation are normalized but not orthogonal state functions, then there arise interferences between these states but not oscillations. It is necessary to remark that the available experimental data are in good agreement with the second approach. So, we come to the conclusion that oscillations do not arise at CP violation in weak interactions in the system of K 0 mesons. Only interference between K S and K L states takes place here.

Deuteron threshold electrodisintegration at high momentum transfer

International Nuclear Information System (INIS)

Schmitt, W.M.; Turchinetz, W.; Williamson, C.F.; Yates, T.C.; Zumbro, J.D.; Lee, K.S.; Baghaei, H.; Churchwell, S.; Hicks, R.S.; Miskimen, R.; Peterson, G.A.; Wang, K.; Bosted, P.E.; Spengos, M.; Frois, B.; Martino, J.; Platchkov, S.; Hotta, A.

1997-01-01

Absolute differential cross sections for the threshold electrodisintegration of the deuteron with good resolution were measured at a laboratory scattering angle of 160 degree for five values of Q 2 ranging from 8.66 to 42.4fm -2 . Comparisons of the data averaged over E np from 0 to 3 MeV and from 0 to 10 MeV are made with nonrelativistic meson exchange calculations. These calculations are sensitive to the nucleon electromagnetic form factors, nucleon-nucleon potential, and relativistic effects. The data are also compared with a hybrid quark-hadron model calculation that describes the deuteron as a six-quark cluster for the short range part of the interaction. Some of these calculations can describe the data reasonably well over certain ranges of Q 2 ; however, none of these calculations can accurately describe the data over the entire measured Q 2 range. copyright 1997 The American Physical Society

Measurement of prompt D0 meson azimuthal anisotropy in PbPb collisions at sqrt(s[NN]) = 5.02 TeV

Energy Technology Data Exchange (ETDEWEB)

Sirunyan, Albert M; et al.

2017-08-11

The prompt D0 meson azimuthal anisotropy coefficients, v[2] and v[3], are measured at midrapidity (abs(y) < 1.0) in PbPb collisions at a center-of-mass energy sqrt(s[NN]) = 5.02 TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (pT) range of 1 to 40 GeV/c, for central and midcentral collisions. The v[2] coefficient is found to be positive throughout the pT range studied. The first measurement of the prompt D0 meson v[3] coefficient is performed, and values up to 0.07 are observed for pT around 4 GeV/c. Compared to measurements of charged particles, a similar pT dependence, but smaller magnitude for pT < 6 GeV/c, is found for prompt D0 meson v[2] and v[3] coefficients. The results are consistent with the presence of collective motion of charm quarks at low pT and a path length dependence of charm quark energy loss at high pT, thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark-gluon plasma.

Antihyperon-hyperon production in the meson exchange framework

International Nuclear Information System (INIS)

Haidenbauer, J.; Holinde, K.; Speth, J.

1992-01-01

Strangeness production processes bar pp→ bar YY (Y=Λ,Σ) have been studied near threshold in a full coupled-channel calculation. The transition interactions are based on K- and K * -meson exchange. The elastic part of the bar pp and bar YY interactions has been derived from a one-boson-exchange version of the Bonn NN potential and a corresponding extension to the hyperon-nucleon case whereas the annihilation part is taken into account by introducing phenomenological optical potentials. First results are presented for the reactions bar pp→ bar ΛΣ 0 +bar Σ 0 Λ as well as bar pp→ bar Σ ± Σ ± , bar Σ 0 Σ 0 , which agree with existing data. As in bar pp→ bar ΛΛ, tensor and spin-triplet dominance is realized in bar pp→ bar Σ Σ but is somewhat reduced in bar pp→ bar Λ Σ 0 +bar Σ 0 Λ. Although bar Σ - Σ - cannot be reached from bar pp by a single transition, the corresponding cross section is only slightly smaller than for bar Σ + Σ + . Initial-and final-state effects play a decisive role, even in cross section ratios

SU(3) properties of semileptonic and nonleptonic decays of mesons

International Nuclear Information System (INIS)

Montvay, I.

1977-11-01

The recent discovery of charmed D and F mesons led to an accumulation of a lot of information on the weak decays of these particles. The facts known at present are generally consistent with the Glashow-Iliopoulos-Maiami scheme for the weak currents, which are predicted the fourth flavour of quarks, the charm. The weak decays of the charmed mesons are governed by SU(3) rules analogous to the Okubo-Zweig-Iizuka rule for strong decays. Such Su(3) rules are given for semileptonic and nonleptonic decays of strange and charmed mesons. These relations depend on the colour structure of currents in the nonleptonic case. (D.P.)

The meson spectroscopy program with CLAS12 at Jefferson Laboratory

Energy Technology Data Exchange (ETDEWEB)

Rizzo, Alessandro [Univ. of Rome Tor Vergata (Italy)

2016-06-01

The study of the hadronic spectrum is one of the most powerful tools to investigate the mechanism at the basis of quark confinement within hadrons. A precise determination of the spectrum allows not only to assess the properties of the hadrons in their fundamental and excited states, but also to investigate the existence of states resulting from alternative configurations of quarks and gluons, such as the glue-balls, hybrid hadrons and many-quarks configurations. The study of the mesonic part of the spectrum can play a central role in this investigation thanks to the strong signature that the hybrid mesons are expected to have: the presence of explicit gluonic degrees of freedom in such states may result in JPC configurations not allowed for the standard q ¯ q states. From the experimental side the expected high-multiplicity decays of the hybrid mesons require an apparatus with high performances in terms of rate-capability, resolution and acceptance. The CLAS12 experiment (formally MesonEx) is one of new-generation experiments at Thomas Jefferson National Laboratory (JLAB) for which an unprecedented statistics of events, with fully reconstructed kinematics for large particle multiplicity decays, will be available. A wide scientific program that will start in 2016 has been deployed for meson spectrum investigation with the CLAS12 apparatus in Hall B at energies up to 11 GeV. One of the main parts of the program is based on the use of the Forward Tagger apparatus, which will allow CLAS12 experiment to extend the study of meson electro-production to the quasi-real photo-production kinematical region (very low Q2), where the production of hybrid mesons is expected to be favoured. The data analysis which is required to extract the signal from hybrid states should go beyond the standard partial wave analysis techniques and a new analysis framework is being set up through the international network Haspect. The Haspect Network gathers people involved into theoretical and

Charged-particle multiplicities in B-meson decay

International Nuclear Information System (INIS)

Alam, M.S.; Csorna, S.E.; Fridman, A.; Hicks, R.G.; Panvini, R.S.; Andrews, D.; Avery, P.; Berkelman, K.; Cabenda, R.; Cassel, D.G.; DeWire, J.W.; Ehrlich, R.; Ferguson, T.; Gilchriese, M.G.D.; Gittelman, B.; Hartill, D.L.; Herrup, D.; Herzlinger, M.; Holzner, S.; Kandaswamy, J.; Kreinick, D.L.; Mistry, N.B.; Morrow, F.; Nordberg, E.; Perchonok, R.; Plunkett, R.; Silverman, A.; Stein, P.C.; Stone, S.; Weber, D.; Wilcke, R.; Sadoff, A.J.; Bebek, C.; Haggerty, J.; Hempstead, M.; Izen, J.M.; Loomis, W.A.; MacKay, W.W.; Pipkin, F.M.; Rohlf, J.; Tanenbaum, W.; Wilson, R.; Chadwick, K.; Chauveau, J.; Ganci, P.; Gentile, T.; Kagan, H.; Kass, R.; Melissinos, A.C.; Olsen, S.L.; Poling, R.; Rosenfeld, C.; Rucinski, G.; Thorndike, E.H.; Green, J.; Sannes, F.; Skubic, P.; Snyder, A.; Stone, R.; Brody, A.; Chen, A.; Goldberg, M.; Horwitz, N.; Lipari, P.; Kooy, H.; Moneti, G.C.; Pistilli, P.

1982-01-01

The charged multiplicity has been measured at the UPSILON(4S) and a value of 5.75 +- 0.1 +- 0.2 has been obtained for the mean charged multiplicity in B-meson decay. Combining this result with the measurement of prompt letpons from B decay, the values 4.1 +- 0.35 +- 0.2 and 6.3 +- 0.2 +- 0.2 are found for the semileptonic and nonleptonic charged multiplicities, respectively. If b→c dominance is assumed for the weak decay of the B meson, then the semileptonic multiplicity is consistent with the recoil mass determined from the lepton momentum spectrum

Are the gluon distributions different in π- and K-mesons?

International Nuclear Information System (INIS)

Batunin, A.V.; Likhoded, A.K.; Kiselev, V.V.

1988-01-01

The experimental data an excess of D-meson production in K - -beam as compared with π - one (NA32 collaboration) is discussed. Such a situation is shown to be possible at larger total number of gluons in K-meson only. However, this is in a disagreemtn with other charm production experiments

Excited meson radiative transitions from lattice QCD using variationally optimized operators

Energy Technology Data Exchange (ETDEWEB)

Shultz, Christian J. [Old Dominion Univ., Norfolk, VA (United States); Dudek, Jozef J. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States); Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2015-06-02

We explore the use of 'optimized' operators, designed to interpolate only a single meson eigenstate, in three-point correlation functions with a vector-current insertion. These operators are constructed as linear combinations in a large basis of meson interpolating fields using a variational analysis of matrices of two-point correlation functions. After performing such a determination at both zero and non-zero momentum, we compute three-point functions and are able to study radiative transition matrix elements featuring excited state mesons. The required two- and three-point correlation functions are efficiently computed using the distillation framework in which there is a factorization between quark propagation and operator construction, allowing for a large number of meson operators of definite momentum to be considered. We illustrate the method with a calculation using anisotopic lattices having three flavors of dynamical quark all tuned to the physical strange quark mass, considering form-factors and transitions of pseudoscalar and vector meson excitations. In conclusion, the dependence on photon virtuality for a number of form-factors and transitions is extracted and some discussion of excited-state phenomenology is presented.

Threshold network of a financial market using the P-value of correlation coefficients

Science.gov (United States)

Ha, Gyeong-Gyun; Lee, Jae Woo; Nobi, Ashadun

2015-06-01

Threshold methods in financial networks are important tools for obtaining important information about the financial state of a market. Previously, absolute thresholds of correlation coefficients have been used; however, they have no relation to the length of time. We assign a threshold value depending on the size of the time window by using the P-value concept of statistics. We construct a threshold network (TN) at the same threshold value for two different time window sizes in the Korean Composite Stock Price Index (KOSPI). We measure network properties, such as the edge density, clustering coefficient, assortativity coefficient, and modularity. We determine that a significant difference exists between the network properties of the two time windows at the same threshold, especially during crises. This implies that the market information depends on the length of the time window when constructing the TN. We apply the same technique to Standard and Poor's 500 (S&P500) and observe similar results.

Neutron stars in relativistic mean field theory with isovector scalar meson

Energy Technology Data Exchange (ETDEWEB)

Kubis, S.; Kutschera, M.; Stachniewicz, S. [H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)

1998-03-01

We study the equation of state (EOS) of {beta}-stable dense matter and models of neutron stars in the relativistic mean field (RMF) theory with the isovector scalar mean field corresponding to the {delta}-meson (a{sub 0}(980)). A range of values of the {delta}-meson coupling compatible with the Bonn potentials is explored. Parameters of the model in the isovector sector are constrained to fit the nuclear symmetry energy, E{sub s}{approx}30 MeV. We find that the quantity most sensitive to the {delta}-meson coupling is the proton fraction of neutron star matter. It increases significantly in the presence of the {delta}-field. The energy per baryon also increases but the effect is smaller. The EOS becomes slightly stiffer and the maximum neutron star mass increases for stronger {delta}-meson coupling. (author) 8 refs, 6 figs, 2 tabs

Measurement of the lifetimes of the neutral and charged D mesons

International Nuclear Information System (INIS)

Gladney, L.D.

1985-03-01

Results are presented on the use of a high-resolution drift chamber in the Mark II Detector at PEP to measure the lifetimes of D 0 and D +- mesons produced in e + e - annihilations at 29 GeV. Based on a sample of 74 events for the D 0 mesons and 23 events for the D +- mesons, the lifetimes are found to be tau/sub D 0 = 4.7/sub -0.8//sup +0.9/ +- 0.5 x 10 -13 s; tau/sub D +- / = 8.9/sub -2.7//sup +3.8/ +- 1.3 x 10 -13 s. The ratio of these lifetimes, tau/sub D 0 //tau/sub D +- / = 1.9/sub -0.7//sup +0.9/ +- 0.3, indicates that the decays of these mesons cannot be explained by the simple spectator model of charmed particle decay

Meson Spectroscopy at COMPASS

CERN Document Server

Grube, Boris

2015-01-01

The COmmon Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron (SPS) aimed at studying the structure and spectrum of hadrons. The two-stage spectrometer has a good acceptance for charged as well as neutral particles over a wide kinematic range and thus allows to access a wide range of reactions. Light mesons are studied with negative (mostly $\\pi^-$) and positive ($p$, $\\pi^+$) hadron beams with a momentum of 190 GeV/$c$. The spectrum of light mesons is investigated in various final states produced in diffractive dissociation reactions at squared four-momentum transfers to the target between 0.1 and 1.0 $(\\text{GeV}/c)^2$. The flagship channel is the $\\pi^-\\pi^+\\pi^-$ final state, for which COMPASS has recorded the currently largest data sample. These data not only allow to measure the properties of known resonances with high precision, but also to search for new states. Among these is a new resonance-like signal, t...

Meson Spectroscopy at COMPASS

CERN Document Server

Grube, Boris

2016-11-29

The goal of the COMPASS experiment at CERN is to study the structure and dynamics of hadrons. The two-stage spectrometer used by the experiment has large acceptance and covers a wide kinematic range for charged as well as neutral particles and can therefore measure a wide range of reactions. The spectroscopy of light mesons is performed with negative (mostly $\\pi^-$) and positive ($p$, $\\pi^+$) hadron beams with a momentum of 190 GeV/$c$. The light-meson spectrum is measured in different final states produced in diffractive dissociation reactions with squared four-momentum transfer $t$ to the target between 0.1 and 1.0 $(\\text{GeV}/c)^2$. The flagship channel is the $\\pi^-\\pi^-\\pi^+$ final state, for which COMPASS has recorded the currently world's largest data sample. These data not only allow to measure the properties of known resonances with high precision, but also to observe new states. Among these is a new axial-vector signal, the $a_1(1420)$, with unusual properties. Novel analysis techniques have been...

Direct production of anti D0 mesons in neutrino-nucleon collisions

International Nuclear Information System (INIS)

Onipchuk, A.B.; Choban, E.A.

1992-01-01

The inclusive production of anti D 0 mesons in neutrino-nucleon collisions is studied from the viewpoint of the quasiparton mechanism. The ratio R anti D 0 υ = σ(υ μ N → μ - X)/σ(υ μ N → μ - X), the kinematic distributions averaged over the υ μ spectrum, and the average kinematic characteristics of the final μ - and anti D 0 mesons are calculated. The number of events with anti D 0 -meson production is estimated as a function of the number of inclusive events

Electroweak production of hybrid mesons in a flux-tube simulation of lattice QCD

International Nuclear Information System (INIS)

Close, F.E.; Dudek, J.J.

2003-01-01

We make the first calculation of the electroweak couplings of hybrid mesons to conventional mesons appropriate to photoproduction and to the decays of B or D mesons. E1 amplitudes are found to be large and may contribute in charge exchange γp→nH + allowing production of (among others) the charged 1 -+ exotic hybrid off a 2 exchange. Axial hybrid meson photoproduction is predicted to be large courtesy of π exchange, and its strange hybrid counterpart is predicted in B→ψK H (1 + ) with branching ratio B∼10 -4 . Higher multipoles and some implications for hybrid charmonium are briefly discussed

Revealing transversity GPDs through the photoproduction of a photon and a ρ meson

Directory of Open Access Journals (Sweden)

Boussarie R.

2016-01-01

Full Text Available Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We discuss the production of a photon and a meson, where the wide angle Compton scattering on a meson subprocess factorizes from generalized parton distribution. We calculate at dominant twist and leading order in αs, the production cross-section of a transversely polarized ρ meson which is sensitive to chiral-odd GPDs, and show that it may be measurable in near future JLab experiments.

Hadronic and leptonic decay widths of D and Ds mesons using Dirac formalism

International Nuclear Information System (INIS)

Vinodkumar, P.C.; Shah, Manan; Patel, Bhavin

2014-01-01

The decay of charged meson is important annihilation channel through the exchange of the virtual W boson. Though this annihilation process is rare, they have clear experimental signatures due to the presence of highly energetic leptons, hadrons in the final state. There exist experimental observations of the hadronic and leptonic decays of D and Ds mesons. The decays of mesons entail an appropriate representation of the initial state of the decaying mesons in terms of the constituent quark and antiquark with their respective momenta and spin. Thus, it is appropriate to compute the branching ratio here

Nonleptonic decay of charmed mesons and chiral lagrangians

International Nuclear Information System (INIS)

Kalinovskij, Yu.L.; Pervushin, V.N.

1978-01-01

Nonleptonic decays of charmed mesons in chiral theory are considered. The lagrangian of strong interaction is taken to be invariant under the SU(4)xSU(4) group. Symmetry breaking is chosen according to the (4,4sup(*))+(4sup(*),4) simplest representation of the SU(4)xSU(4) group. The lagrangian of weak interaction is taken in the ''current x current'' form and satisfies exactly the rule probabilities of decays for D and F mesons are compared with available experimental data

Meson-baryon four-body reaction amplitudes in exact SU(4)

International Nuclear Information System (INIS)

Liede, I.; Maalampi, J.; Roos, M.

1976-01-01

Fully SU(4) symmetric meson-baryon four body reaction amplitudes are presented in terms of SU(4) eigenamplitudes. The mesons and baryons considered belong to the SU(4) representations 15 and 20, respectively. Using these reletions, the cross-sections for the production of charmed particles can be predicted from known uncharmed reactions. (author)

On exotic hybrid meson production in γ*γ collisions

International Nuclear Information System (INIS)

Anikin, I.V.; Teryaev, O.V.; Pire, B.; Szymanowski, L.; Universite de Liege; Paris-11 Univ., 91 - Orsay; Wallon, S.

2006-01-01

We present a theoretical study of exotic hybrid meson (J PC =1 -+ ) production in photon-photon collisions where one of the photons is deeply virtual, including twist two and twist three contributions. We calculate the cross section of this process, which turns out to be large enough to imply sizeable counting rates in the present high luminosity electron-positron colliders. We emphasize the importance of the πη decay channel for the detection of the hybrid meson candidate π 1 (1400) and calculate the cross section and the angular distribution for πη pair production in the unpolarized case. This angular distribution is a useful tool for disentangling the hybrid meson signal from the background. Finally, we calculate the single spin asymmetry associated with one initial longitudinally polarized lepton. (orig.)

Relative rates of B meson decays into psi(2S) and J/psi mesons

OpenAIRE

Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S. H.; Ahsan, M.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Anastasoaie, M.

2009-01-01

We report on a study of the relative rates of B meson decays into ψ(2S) and J/ψ mesons using 1.3  fb-1 of pp̅ collisions at √s=1.96  TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe the channels Bs0→ψ(2S)ϕ, Bs0→J/ψϕ, B±→ψ(2S)K±, and B±→J/ψK± and we measure the relative branching fractions for these channels to be B(Bs0→ψ(2S)ϕ)/B(Bs0→J/ψϕ)=0.53±0.10(stat)±0.07(syst)±0.06(B), B(B±→ψ(2S)K±)/B(B±→J/ψK±)=0.63±0.05(stat)±0.03(syst)±0.07(B),where the final erro...

Chiral symmetry breaking and the spin content of the {rho} and {rho}{sup '} mesons

Energy Technology Data Exchange (ETDEWEB)

Glozman, L.Ya., E-mail: leonid.glozman@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Lang, C.B., E-mail: christian.lang@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Limmer, M., E-mail: markus.limmer@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria)

2011-11-03

Using interpolators with different SU(2){sub L}xSU(2){sub R} transformation properties we study the chiral symmetry and spin contents of the {rho} and {rho}{sup '} mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar {gamma}{sup i}{tau}q and q-bar {sigma}{sup 0}i{tau}q interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of {approx}1 fm. In the ground state {rho} meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2){sub b} chiral representations with the former being the leading contribution. In contrast, in the {rho}{sup '} meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2){sub b}. Using a unitary transformation from the chiral basis to the {sup 2S+1}L{sub J} basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The {rho} meson is practically a {sup 3}S{sub 1} state with no obvious trace of a 'spin crisis'. The {rho}{sup '} meson has a sizeable contribution of the {sup 3}D{sub 1} wave, which implies that the {rho}{sup '} meson cannot be considered as a pure radial excitation of the {rho} meson.

Semileptonic decays of the B{sub c} meson

Energy Technology Data Exchange (ETDEWEB)

Barik, N [Department of Physics, Utkal University, Bhubaneswar-751004 (India); Naimuddin, Sk [Department of Physics, Maharishi College of Natural Law, Bhubaneswar-751007 (India); Dash, P C [Department of Physics, Prananath Autonomous College, Khurda-752057 (India); Kar, Susmita [Department of Physics, North Orissa University, Baripada-757003 (India)

2009-10-01

We study the semileptonic transitions B{sub c}{yields}{eta}{sub c},J/{psi},D,D*,B,B*,B{sub s},B{sub s}* in the leading order in the framework of a relativistic independent quark model based on a confining potential in the equally mixed scalar-vector harmonic form. We compute relevant weak form factors as overlap integrals of the meson-wave functions obtained in the relativistic independent quark model in the whole accessible kinematical range. We predict that the semileptonic transitions of the B{sub c} meson are mostly dominated by two Cabibbo-Kobayashi-Maskawa (CKM)-favored modes, B{sub c}{yields}B{sub s}(B{sub s}*)e{nu}, contributing about 77% of the total decay width, and its decays to vector meson final states take place in the predominantly transverse mode. Our predicted values for the total decay rates, branching ratios, polarization ratios, the forward-backward asymmetry factor, etc., are broadly in agreement with other model predictions.

Mesonic and baryonic Regge trajectories with quantized masses

International Nuclear Information System (INIS)

Hothi, N.; Bisht, S.

2011-01-01

We have constructed some Regge trajectories for mesons and baryons by taking the 70 MeV spinless mass quanta as the ultimate building block for the light hadrons. In order to make masses integral multiples of seventy, small changes in masses has been made with due explanation. We have shown how a linear relationship between J and M 2 is maintained by considering quantized hadron masses, which is a direct consequence of the string model and gives a strong clue for quark confinement. It has also been established that mesons and baryons have different slopes and the slopes of baryons is less than the slope of the mesons. This clearly defies the concept of universality of slopes (α ≅ 1.1 GeV 2 ) of hadrons, which can only be achieved if the strings joining the quarks have constant string tension α 1/(2πω) (where ω is the string tension). (author)

Light Scalar Mesons in Central Production at COMPASS

CERN Document Server

Austregesilo, A.

2016-01-01

COMPASS is a fixed-target experiment at the CERN SPS that studies the spectrum of light-quark hadrons. In 2009, it collected a large dataset using a $190\\,$GeV$/c$ positive hadron beam impinging on a liquid-hydrogen target in order to measure the central exclusive production of light scalar mesons. One of the goals is the search for so-called glueballs, which are hypothetical meson-like objects without valence-quark content. We study the decay of neutral resonances by selecting centrally produced pion pairs from the COMPASS dataset. The angular distributions of the two pseudoscalar mesons are decomposed in terms of partial waves, where particular attention is paid to the inherent mathematical ambiguities. The large dataset allows us to perform a detailed analysis in bins of the two squared four-momentum transfers carried by the exchange particles in the reaction. Possible parameterisations of the mass dependence of the partial-wave amplitudes in terms of resonances are also discussed.

Decay of the Ds-meson

International Nuclear Information System (INIS)

Duong Van Phi; Duong Anh Duc

1993-08-01

The decay channels of the D s -meson are deduced from a Selection Rule and a Lagrangian, formed on L*O(4) group invariance and on principle of minimal structure. A comparison of the results with experimental data is made. (author). 4 refs

Exclusive meson production at COMPASS

CERN Document Server

Pochodzalla, Josef; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc; Pochodzalla, Josef; Mankiewicz, Lech; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc

1999-01-01

We explore the feasibility to study exclusive meson production (EMP) in hard muon-proton scattering at the COMPASS experiment. These measurements constrain the off-forward parton distributions (OFPD's) of the proton, which are related to the quark orbital contribution to the proton spin.

Short Rayleigh Length Free Electron Lasers

CERN Document Server

Crooker, P P; Armstead, R L; Blau, J

2004-01-01

Conventional free electron laser (FEL) oscillators minimize the optical mode volume around the electron beam in the undulator by making the resonator Rayleigh length about one third of the undulator length. This maximizes gain and beam-mode coupling. In compact configurations of high-power infrared FELs or moderate power UV FELs, the resulting optical intensity can damage the resonator mirrors. To increase the spot size and thereby reduce the optical intensity at the mirrors below the damage threshold, a shorter Rayleigh length can be used, but the FEL interaction is significantly altered. A new FEL interaction is described and analyzed with a Rayleigh length that is only one tenth the undulator length, or less. The effect of mirror vibration and positioning are more critical in the short Rayleigh length design, but we find that they are still within normal design tolerances.

Investigation of Semileptonic {ital B} Meson Decays to {ital p} -Wave Charm Mesons

Energy Technology Data Exchange (ETDEWEB)

Anastassov, A.; Duboscq, J.E.; Fujino, D.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Spencer, M.B.; Sung, M.; Undrus, A.; Wanke, R.; Wolf, A.; Zoeller, M.M. [Ohio State University, Columbus, Ohio 43210 (United States); Nemati, B.; Richichi, S.J.; Ross, W.R.; Skubic, P. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Hinson, J.W.; Menon, N.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P.; Yurko, M. [Purdue University, West Lafayette, Indiana 47907 (United States); Glenn, S.; Johnson, S.D.; Kwon, Y.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Savinov, V.; Ugolini, D.; Wang, R.; Zhou, X. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States); Coan, T.E.; Fadeyev, V.; Korolkov, I.; Maravin, Y.; Narsky, I.; Shelkov, V.; Staeck, J.; Stroynowski, R.; Volobouev, I.; Ye, J. [Southern Methodist University, Dallas, Texas 75275 (United States); Artuso, M.; Efimov, A.; Goldberg, M.; He, D.; Kopp, S.; Moneti, G.C.; Mountain, R.; Schuh, S.; Skwarnicki, T.; Stone, S.; Viehhauser, G.; Xing, X. [Syracuse University, Syracuse, New York 13244 (United States); Bartelt, J.; Csorna, S.E.; Jain, V.; McLean, K.W.; Marka, S. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Godang, R.; Kinoshita, K.; Lai, I.C.; Pomianowski, P.; Schrenk, S. [Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J. [Wayne State University, Detroit, Michigan 48202 (United States); Barish, B.; Chadha, M.; Chan, S.; Eigen, G.; Miller, J.S.; OGrady, C.; Schmidtler, M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F. [California Institute of Technology, Pasadena, California 91125 (United States); Bliss, D.W.; Masek, G.; Paar, H.P.; Prell, S.; Sharma, V. and others

1998-05-01

We have studied semileptonic B meson decays with a p -wave charm meson in the final state using 3.29{times}10{sup 6} B{ovr B} events collected with the CLEOII detector at the Cornell Electron-Positron Storage Ring. We find a value for the exclusive semileptonic product branching fraction B(B{sup {minus}}{r_arrow}D{sup 0}{sub 1} {ell}{sup {minus}}{ovr {nu}}{sub {ell}}) B(D{sup 0}{sub 1}{r_arrow}D{sup {asterisk}+} {pi}{sup {minus}})=(0.373{plus_minus}0.085{plus_minus} 0.052{plus_minus}0.024){percent} and an upper limit for B(B{sup {minus}}{r_arrow}D{sup {asterisk}0}{sub 2} {ell}{sup {minus}}{ovr {nu}}{sub {ell}}) B(D{sup {asterisk}0}{sub 2}{r_arrow}D{sup {asterisk}+ }{pi}{sup {minus}}){lt}0.16{percent} (90{percent} C.L.). Furthermore, we present the first measurement of the q{sup 2} spectrum for B{sup {minus}}{r_arrow}D{sup 0}{sub 1}{ell}{sup {minus}} {ovr {nu}}{sub {ell}} . {copyright} {ital 1998} {ital The American Physical Society}

Strange Meson Radiative Capture on the Proton in Low Energy QCD Lagrangian

Institute of Scientific and Technical Information of China (English)

ZHOU Li-Juan; MA Wei-Xing

2002-01-01

Based on our low energy QCD Lagrangian description of strange meson photoproduction off the protonand the crossing symmetry, the strange meson radiative capture on the proton, K- + p →γ + A, is investigated in the[SUsF (6) O(3)]sym. SUc (3) quark model of baryon structure with the same input parameter, the only strong couplingconstant aM, as that in the strange meson photoproduction off the proton γ + p → K+ + A, a crossing channel of thecapture reaction. A good agreement on the branching ratio between the predictions and data is obtained successfully.This excellent fit indicates that our low energy QCD Lagrangian theory with only one free parameter is an advancedand unified description of strange meson photoproduction and its associated radiative capture.

Holographic estimate of the meson cloud contribution to nucleon axial form factor

Science.gov (United States)

Ramalho, G.

2018-04-01

We use light-front holography to estimate the valence quark and the meson cloud contributions to the nucleon axial form factor. The free couplings of the holographic model are determined by the empirical data and by the information extracted from lattice QCD. The holographic model provides a good description of the empirical data when we consider a meson cloud mixture of about 30% in the physical nucleon state. The estimate of the valence quark contribution to the nucleon axial form factor compares well with the lattice QCD data for small pion masses. Our estimate of the meson cloud contribution to the nucleon axial form factor has a slower falloff with the square momentum transfer compared to typical estimates from quark models with meson cloud dressing.

Universal Behavior in Excited Heavy-Light and Light-Light Mesons

OpenAIRE

Olsson, M. G.

1996-01-01

A common pattern of large orbital and radial excitations in heavy-light and light-light mesons is demonstrated. Within a general potential model the Regge slopes of the light degrees of freedom for these mesons are shown to be in the ratio of two. The possibility of ``tower'' degeneracy occurs only with pure scalar confinement.

Calculation of excited vector meson electron widths using QCD sum rules

International Nuclear Information System (INIS)

Geshkenbein, B.V.

1984-01-01

The sum rules are suggested which allow one to calculate the electron widths of excited vector mesons of the PSI, UPSILON, rho meson family assuming the values of their masses to be known. The calculated values of the electron widths agree with experiment

Unitary eikonal formalism for multiproduction of isovector mesons at high energy

CERN Document Server

Redei, L B

1973-01-01

Unitary eikonal models for multiproduction of isovector mesons are discussed in general terms. A closed analytic expression is derived for the partial production cross sections and for the meson multiplicity moments. A simple class of models is discussed in more detail. (11 refs).

Asymmetries in heavy meson production from light quark fragmentation

International Nuclear Information System (INIS)

Dias de Deus, J.; Duraes, F.

2000-01-01

We discuss the possibility of the asymmetry in D - /D + production from π - beams, being a direct consequence of the properties of the light quark fragmentation function into heavy mesons. The main features of the asymmetry, as a function of x F , are easily described. An integrated sum rule for the D - , D + multiplicity difference is presented. Predictions for the asymmetry in B meson production are given. (orig.)

Tetraquark and two-meson states at large N{sub c}

Energy Technology Data Exchange (ETDEWEB)

Lucha, Wolfgang [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); Melikhov, Dmitri [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); M.V. Lomonosov Moscow State University, D.V. Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); University of Vienna, Faculty of Physics, Vienna (Austria); Sazdjian, Hagop [IPNO, Universite Paris-Sud, CNRS-IN2P3, Universite Paris-Saclay, Orsay (France)

2017-12-15

Considering four-point correlation functions of color-singlet quark bilinears, we investigate, in the large-N{sub c} limit of QCD, the subleading diagrams that involve, in the s-channel of meson-meson scattering amplitudes, two-quark-two-antiquark intermediate states. The latter contribute, together with gluon exchanges, to the formation, at the hadronic level, of two-meson and tetraquark intermediate states. It is shown that the two-meson contributions, which are predictable, in general, from leading-order N{sub c}-behaviors, consistently satisfy the constraints resulting from the 1/N{sub c} expansion procedure and thus provide a firm basis for the extraction of tetraquark properties from N{sub c}-subleading diagrams. We find that, in general, tetraquarks, if they exist in compact form, should have narrow decay widths, of the order of N{sub c}{sup -2}. For the particular case of exotic tetraquarks, involving four different quark flavors, two different types of tetraquark are needed, each having a preferred decay channel, to satisfy the consistency constraints. (orig.)

Meson thermalization by baryon injection in D4/D6 model

Science.gov (United States)

Rezaei, Z.

2016-12-01

We study meson thermalization in a strongly coupled plasma of quarks and gluons using AdS/CFT duality technique. Four dimensional large-Nc QCD is considered as a theory governing this quark-gluon plasma (QGP) and D4/D6-brane model is chosen to be its holographic dual theory. In order to investigate meson thermalization, we consider a time-dependent change of baryon number chemical potential. Thermalization in gauge theory side corresponds to horizon formation on the probe flavor brane in the gravity side. The gravitational dual theory is compactified on a circle that the inverse of its radius is proportional to energy scale of dual gauge theory. It is seen that increase of this energy scale results in thermalization time dilation. In addition we study the effect of magnetic field on meson thermalization. It will be seen that magnetic field also prolongs thermalization process by making mesons more stable.

Electromagnetic Transition Form Factor of the η meson with WASA-at-COSY

Science.gov (United States)

Goswami, A.

2016-11-01

In this work we present a study of the Dalitz decay η → γe+e-. The aim of this work is to measure the transition form factor of the η meson. The transition form factor of the η meson describes the electromagnetic structure of the meson. The study of the Dalitz decay helps to calculate the transition form factor of the η meson. When a particle is point-like it's decay rate can be calculated within QED. However, the complex structure of the meson modifies its decay rate. The transition form factor is determined by comparing the lepton-antilepton invariant mass distribution with QED. For this study data on proton-proton reaction at a beam energy of 1.4 GeV has been collected with WASA-at-COSY detector at Forschungszentrum Juelich, Germany. In the higher invariant mass region recent theoretical calculations slightly deviate from the fit to the data. We expect better results in the higher invariant mass region than previous measurements. The preliminary results of the analysis will be presented.

Electromagnetic Transition Form Factor of the η meson with WASA-at-COSY

Directory of Open Access Journals (Sweden)

Goswami A.

2016-01-01

Full Text Available In this work we present a study of the Dalitz decay η → γe+e−. The aim of this work is to measure the transition form factor of the η meson. The transition form factor of the η meson describes the electromagnetic structure of the meson. The study of the Dalitz decay helps to calculate the transition form factor of the η meson. When a particle is point-like it’s decay rate can be calculated within QED. However, the complex structure of the meson modifies its decay rate. The transition form factor is determined by comparing the lepton-antilepton invariant mass distribution with QED. For this study data on proton-proton reaction at a beam energy of 1.4 GeV has been collected with WASA-at-COSY detector at Forschungszentrum Juelich, Germany. In the higher invariant mass region recent theoretical calculations slightly deviate from the fit to the data. We expect better results in the higher invariant mass region than previous measurements. The preliminary results of the analysis will be presented.

QCD sum-rules analysis of vector (1-) heavy quarkonium meson-hybrid mixing

Science.gov (United States)

Palameta, A.; Ho, J.; Harnett, D.; Steele, T. G.

2018-02-01

We use QCD Laplace sum rules to study meson-hybrid mixing in vector (1-) heavy quarkonium. We compute the QCD cross-correlator between a heavy meson current and a heavy hybrid current within the operator product expansion. In addition to leading-order perturbation theory, we include four- and six-dimensional gluon condensate contributions as well as a six-dimensional quark condensate contribution. We construct several single and multiresonance models that take known hadron masses as inputs. We investigate which resonances couple to both currents and so exhibit meson-hybrid mixing. Compared to single resonance models that include only the ground state, we find that models that also include excited states lead to significantly improved agreement between QCD and experiment. In the charmonium sector, we find that meson-hybrid mixing is consistent with a two-resonance model consisting of the J /ψ and a 4.3 GeV resonance. In the bottomonium sector, we find evidence for meson-hybrid mixing in the ϒ (1 S ) , ϒ (2 S ), ϒ (3 S ), and ϒ (4 S ).

Study of temporal quantum correlations in decohering B and K meson systems

Science.gov (United States)

Naikoo, Javid; Alok, Ashutosh Kumar; Banerjee, Subhashish

2018-03-01

In this work we study temporal quantum correlations, quantified by Leggett-Garg (LG) and LG-type inequalities, in the B and K meson systems. We use the tools of open quantum systems to incorporate the effect of decoherence which is quantified by a single phenomenological parameter. The effect of C P violation is also included in our analysis. We find that the LG inequality is violated for both B and K meson systems, the violation being most prominent in the case of K mesons and least for Bs system. Since the systems with no coherence do not violate LGI, incorporating decoherence is expected to decrease the extent of violation of LGI and is clearly brought out in our results. We show that the expression for the LG functions depends upon an additional term, apart from the experimentally measurable meson transition probabilities. This term vanishes in the limit of zero decoherence. On the other hand, the LG-type parameter can be directly expressed in terms of transition probabilities, making it a more appropriate observable for studying temporal quantum correlations in neutral meson systems.

Production of excited charm and charm-strange mesons at HERA

International Nuclear Information System (INIS)

Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M.C.K.; Antonioli, P.; Bari, G.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cindolo, F.; Corradi, M.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Antonelli, S.; Basile, M.; Bindi, M.; Cifarelli, L.; Contin, A.; De Pasquale, S.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Hartmann, H.; Hilger, E.; Jakob, H.P.; Juengst, M.; Nuncio-Quiroz, A.E.; Paul, E.; Samson, U.; Schoenberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N.H.; Heath, G.P.; Morris, J.D.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J.Y.; Ibrahim, Z.A.; Kamaluddin, B.; Wan Abdullah, W.A.T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bold, T.; Grabowska-Bold, I.; Kisielewska, D.; Lukasik, J.; Przybycien, M.; Suszycki, L.; Kotanski, A.; Slominski, W.; Behrens, U.; Blohm, C.; Bonato, A.; Borras, K.; Ciesielski, R.; Coppola, N.; Fang, S.; Fourletova, J.; Geiser, A.; Goettlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Huettmann, A.; Januschek, F.; Kahle, B.; Katkov, I.I.; Klein, U.; Koetz, U.; Kowalski, H.; Lobodzinska, E.; Loehr, B.; Mankel, R.; Melzer-Pellmann, I.A.; Miglioranzi, S.; Montanari, A.; Namsoo, T.; Notz, D.; Parenti, A.; Rinaldi, L.; Roloff, P.; Rubinsky, I.; Santamarta, R.; Schneekloth, U.; Spiridonov, A.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Yaguees Molina, A.G.; Youngman, C.; Zeuner, W.; Drugakov, V.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P.G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N.N.; Bussey, P.J.; Doyle, A.T.; Dunne, W.; Forrest, M.; Rosin, M.; Saxon, D.H.; Skillicorn, I.O.; Gialas, I.; Papageorgiu, K.; Holm, U.; Klanner, R.; Lohrmann, E.; Schleper, P.; Schoerner-Sadenius, T.; Sztuk, J.; Stadie, H.; Turcato, M.; Foudas, C.; Fry, C.; Long, K.R.; Tapper, A.D.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A.N.; Boos, E.G.; Pokrovskiy, N.S.; Zhautykov, B.O.; Aushev, V.; Bachynska, O.; Borodin, M.; Kadenko, I.; Kozulia, A.; Libov, V.; Lisovyi, M.; Lontkovskyi, D.; Makarenko, I.; Sorokin, I.; Verbytskyi, A.; Volynets, O.; Son, D.; Favereau, J. de; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; Peso, J. del; Ron, E.; Soares, M.; Terron, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Schwartz, J.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B.A.; Gladkov, D.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R.K.; Ermolov, P.F.; Gladilin, L.K.; Golubkov, Yu.A.; Khein, L.A.; Korzhavina, I.A.; Kuzmin, V.A.; Levchenko, B.B.; Lukina, O.Yu.; Proskuryakov, A.S.; Shcheglova, L.M.; Zotkin, D.S.; Abt, I.; Caldwell, A.; Kollar, D.; Reisert, B.; Schmidke, W.B.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vazquez, M.; Wiggers, L.; Bruemmer, N.; Bylsma, B.; Durkin, L.S.; Lee, A.; Ling, T.Y.; Allfrey, P.D.; Bell, M.A.; Cooper-Sarkar, A.M.; Devenish, R.C.E.; Ferrando, J.; Foster, B.; Korcsak-Gorzo, K.; Oliver, K.; Robertson, A.; Uribe-Estrada, C.; Walczak, R.; Bertolin, A.; Dal Corso, F.; Dusini, S.; Longhin, A.; Stanco, L.; Bellan, P.; Brugnera, R.; Carlin, R.; Garfagnini, A.; Limentani, S.; Oh, B.Y.; Raval, A.; Ukleja, J.; Whitmore, J.J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J.E.; Hart, J.C.

2009-01-01

The production of excited charm, D 1 (2420) 0 and D 2 * (2460) 0 , and charm-strange, D s 1(2536) ± , mesons in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 126 pb -1 . Masses, widths and helicity parameters were determined. The measured yields were converted to the rates of c quarks hadronising as a given excited charm meson and to the ratios of the dominant D 2 * (2460) 0 and D s1 (2536) ± branching fractions. A search for the radially excited charm meson, D *' (2640) ± , was also performed. The results are compared with those measured previously and with theoretical expectations. (orig.)

The Chiral and Angular Momentum Content of the ρ-Meson

Science.gov (United States)

Glozman, L. Ya.; Lang, C. B.; Limmer, M.

2010-01-01

It is possible to define and calculate in a gauge-invariant manner the chiral as well as the partial wave content of the quark-antiquark Fock component of a meson in the infrared, where mass is generated. Using the variational method and a set of interpolators that span a complete chiral basis we extract in a lattice QCD Monte Carlo simulation with n f = 2 dynamical light quarks the orbital angular momentum and spin content of the ρ-meson. We obtain in the infrared a simple 3 S 1 component as a leading component of the ρ-meson with a small admixture of the 3 D 1 partial wave, in agreement with the SU(6) flavor-spin symmetry.

Non-leptonic weak decay rate of explicitly flavored heavy mesons

International Nuclear Information System (INIS)

Suzuki, M.; California Univ., Berkeley

1981-01-01

It is argued quantitatively that a large difference between the D 0 and D + lifetimes is mainly due to non-perturbative long-distance effects. The total non-leptonic weak decay rates are related to the soft limit of short-distance processes. Scaling laws for the decay rates of heavy mesons with respect to mass are inferred from the QCD analysis of the soft limit of fragmentation. It is found that the decay rates are not determined by the disconnected spectator diagrams alone even in the limit of the heavy quark mass M Going to infinity ( 5 exp √ c log M. Some numerical discussion is made for the decay of B mesons and T mesons. (orig.)

Production of excited charm and charm-strange mesons at HERA

International Nuclear Information System (INIS)

Chekanov, S.; Derrick, M.; Magill, S.

2008-07-01

The production of excited charm, D 1 (2420) 0 and D * 2 (2460) 0 , and charm-strange, D s1 (2536) ± , mesons in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 126 pb -1 . Masses, widths and helicity parameters were determined. The measured yields were converted to the rates of c quarks hadronising as a given excited charm meson and to the ratios of the dominant D * 2 (2460) 0 and D s1 (2536) ± branching fractions. A search for the radially excited charm meson, D *' (2640) ± , was also performed. The results are compared with those measured previously and with theoretical expectations. (orig.)

Baryon and meson phenomenology in the extended Linear Sigma Model

Energy Technology Data Exchange (ETDEWEB)

Giacosa, Francesco; Habersetzer, Anja; Teilab, Khaled; Eshraim, Walaa; Divotgey, Florian; Olbrich, Lisa; Gallas, Susanna; Wolkanowski, Thomas; Janowski, Stanislaus; Heinz, Achim; Deinet, Werner; Rischke, Dirk H. [Institute for Theoretical Physics, J. W. Goethe University, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); Kovacs, Peter; Wolf, Gyuri [Institute for Particle and Nuclear Physics, Wigner Research Center for Physics, Hungarian Academy of Sciences, H-1525 Budapest (Hungary); Parganlija, Denis [Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, A-1040 Vienna (Austria)

2014-07-01

The vacuum phenomenology obtained within the so-called extended Linear Sigma Model (eLSM) is presented. The eLSM Lagrangian is constructed by including from the very beginning vector and axial-vector d.o.f., and by requiring dilatation invariance and chiral symmetry. After a general introduction of the approach, particular attention is devoted to the latest results. In the mesonic sector the strong decays of the scalar and the pseudoscalar glueballs, the weak decays of the tau lepton into vector and axial-vector mesons, and the description of masses and decays of charmed mesons are shown. In the baryonic sector the omega production in proton-proton scattering and the inclusion of baryons with strangeness are described.

Effective meson lagrangian with chiral and heavy quark symmetries from quark flavor dynamics

International Nuclear Information System (INIS)

Ebert, D.; Feldmann, T.; Friedrich, R.; Reinhardt, H.

1994-06-01

By bosonization of an extended NJL model we derive an effective meson theory which describes the interplay between chiral symmetry and heavy quark dynamics. This effective theory is worked out in the low-energy regime using the gradient expansion. The resulting effective lagrangian describes strong and weak interactions of heavy B and D mesons with pseudoscalar Goldstone bosons and light vector and axial-vector mesons. Heavy meson weak decay constants, coupling constants and the Isgur-Wise function are predicted in terms of the model parameters partially fixed from the light quark sector. Explicit SU(3) F symmetry breaking effects are estimated and, if possible, confronted with experiment. (orig.)

Decay of the Bottom mesons

International Nuclear Information System (INIS)

Duong Van Phi; Duong Anh Duc

1992-12-01

The channels of the decay of Bottom mesons are deduced from a selection rule and the Lagrangians which are formed on the LxO(4) invariance and the principle of minimal structure. The estimation of the corresponding decay probabilities are considered. (author). 21 refs

Distribution amplitudes of vector mesons

Energy Technology Data Exchange (ETDEWEB)

Braun, V.M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Broemmel, D. [Deutsches Elektronen-Synchrotron, Hamburg (Germany); Goeckeler, M. [Regensburg Univ. (DE). Inst. fuer Theoretische Physik] (and others)

2007-11-15

Results are presented for the lowest moment of the distribution amplitude for the K{sup *} vector meson. Both longitudinal and transverse moments are investigated. We use two flavours of O(a) improved Wilson fermions, together with a non-perturbative renormalisation of the matrix element. (orig.)

Study of open-charm 0{sup +} states in unitarized chiral effective theory with one-loop potentials

Energy Technology Data Exchange (ETDEWEB)

Du, Meng-Lin [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Guo, Feng-Kun [Chinese Academy of Sciences, CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Institut fuer Kernphysik and Juelich Center for Hadron Physics (Germany); Yao, De-Liang [Forschungszentrum Juelich, Institute for Advanced Simulation, Institut fuer Kernphysik and Juelich Center for Hadron Physics (Germany); Instituto de Fisica Corpuscular (Centro mixto CSIC-UV), Institutos de Investigacion de Paterna, Valencia (Spain)

2017-11-15

Chiral potentials are derived for the interactions between Goldstone bosons and pseudo-scalar charmed mesons up to next-to-next-to-leading order in a covariant chiral effective field theory with explicit vector charmed-meson degrees of freedom. Using the extended-on-mass-shell scheme, we demonstrate that the ultraviolet divergences and the so-called power counting breaking terms can be properly absorbed by the low-energy constants of the chiral Lagrangians. We calculate the scattering lengths by unitarizing the one-loop potentials and fit them to the data extracted from lattice QCD. The obtained results are compared to the ones without an explicit contribution of vector charmed mesons given previously. It is found that the difference is negligible for S-wave scattering in the threshold region. This validates the use of D*-less one-loop potentials in the study of the pertinent scattering lengths. We search for dynamically generated open-charm states with J{sup P} = 0{sup +} as poles of the S-matrix on various Riemann sheets. The trajectories of those poles for varying pion masses are presented as well. (orig.)

Study of B Meson Decays to ppbarh Final States

Energy Technology Data Exchange (ETDEWEB)

Hryn' ova, Tetiana B.; /SLAC

2006-03-22

B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X

Spontaneous symmetry breaking and vector-meson dominance

International Nuclear Information System (INIS)

Caldi, D.G.; Pagels, H.

1977-01-01

This article is a continuation of our previous work on the rho-π puzzle. It examines further consequences of the unification of partial conservation of axial-vector current (PCAC) and vector-meson dominance (VMD) in which the pion is a Goldstone state and the rho is a ''dormant'' Goldstone state. Our new picture of the vector mesons does not require an A 1 meson although such a state is not ruled out. The Weinberg sum rules which provide the raison d'etre for the A 1 are reexamined. The first Weinberg sum rule can be accommodated without a narrow A 1 state although some enhancement seems required. Examining the J/sup P C/ = 1 +- nonet we conclude that a new state, the isoscalar octet partner of the B (1235) should exist around 1.7 GeV assuming ideal mixing. Without a detailed assumption on the mixing angle, its mass should be in the range 1.4 to 1.7 GeV. We also discuss the photon-rho interactions. In the standard VMD picture the predicted rate for rho → π + γ fails by five standard deviations, while in our picture this undesired result is averted

Search for Neutrinoless τ Decays Involving π0 or η Mesons

International Nuclear Information System (INIS)

Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J.; Barish, B.; Chadha, M.; Chan, S.; Eigen, G.; Miller, J.S.; OGrady, C.; Schmidtler, M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F.; Asner, D.M.; Bliss, D.W.; Brower, W.S.; Masek, G.; Paar, H.P.; Prell, S.; Sharma, V.; Gronberg, J.; Hill, T.S.; Kutschke, R.; Lange, D.J.; Menary, S.; Morrison, R.J.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Roberts, D.; Ryd, A.; Witherell, M.S.; Balest, R.; Behrens, B.H.; Cho, K.; Ford, W.T.; Park, H.; Rankin, P.; Roy, J.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berger, B.E.; Berkelman, K.; Bloom, K.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Dickson, M.; Drell, P.S.; Ecklund, K.M.; Ehrlich, R.; Elia, R.; Foland, A.D.; Gaidarev, P.; Galik, R.S.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Hopman, P.I.; Kandaswamy, J.; Kim, P.C.; Kreinick, D.L.; Lee, T.; Liu, Y.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Valant-Spaight, B.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Prescott, C.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Yamamoto, H.; Browder, T.E.; Li, F.; Li, Y.; Rodriguez, J.L.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.

1997-01-01

We have searched for lepton flavor violating decays of the τ lepton using final states with an electron or a muon and one or two π 0 or η mesons but no neutrinos. The data used in the search were collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR) and correspond to an integrated luminosity of 4.68 fb -1 . No evidence for signals was found, resulting in much improved limits on the branching fractions for the one-meson modes and the first upper limits for the two-meson modes. copyright 1997 The American Physical Society

Subtracted Dispersion Relations for In-medium Meson Correlators in QCD Sum Rules

Energy Technology Data Exchange (ETDEWEB)

Florkowski, W; Broniowski, W [The H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)

1999-01-01

We analyze subtracted dispersion relations for meson correlators at finite baryon density and temperature. Such relations are needed for QCD sum rules. We point out that importance of scattering terms, as well as finite, well-defined subtraction constants. Both are necessary for consistency, in particular for the equality of the longitudinal and transverse correlators in the limit of the vanishing three-momentum of mesons relative to the medium. We present detailed calculations in various mesonic channels of the Fermi gas of nucleons. (author)

Exclusive semileptonic decays of charmed and b-flavored mesons

International Nuclear Information System (INIS)

Barik, N.; Tripathy, S.K.; Kar, S.; Dash, P.C.

1997-01-01

We investigate the exclusive semileptonic decays of (B,B s ;D,D s ) mesons into less heavy as well as light mesons in a field-theoretic framework based on the independent quark model with a confining potential in scalar-vector-harmonic form. With the recoil effect properly taken into account, the present model describes consistently the semileptonic decays of charmed and b-flavored mesons, agreeing well with the experimental data. The transition form factors in the heavy to heavy decays, in particular, comply with the heavy quark symmetry relations expected from HQET. The CKM parameters extracted in this formalism are close to the existing data. The model prediction also satisfies the Isgur-Wise relation connecting the form factors of the semileptonic (B→ρeν) and that of rare radiative decay (B→ργ). copyright 1997 The American Physical Society

A phenomenological analysis of non-resonant charm meson decays

Energy Technology Data Exchange (ETDEWEB)

Bediaga, I.; Goebel, C. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Mendez-Galain, R. [Montevideo Univ. (Uruguay). Facultad de Ingenieria

1997-07-01

We analyse the consequences of the usual assumption of a constant function to fit non-resonant decays from experimental Dalitz plot describing charmed meson decays. We first show, using the D{sup +} -> K{sup 0} {pi}{sup +} {pi}{sup 0} decay channel as an example, how an inadequate extraction of the non-resonant contribution could yield incorrect measurements for the resonant channels. We analyse how the correct study of this decay will provide a test for the validity of factorization in D meson decays. Finally, we show how form factors that can be measured from the D{sup +}{sub s} -> {pi}{sup -} {pi}{sup +} {pi}{sup +} decay. We emphasize its relevance for the study of the decay {tau} -> v{sub t} 3{pi} and the extraction of the {alpha}{sub 1} meson width. (author) 26 refs., 6 figs.

High statistics inclusive phi-meson production at SPS energies

International Nuclear Information System (INIS)

Dijkstra, H.B.

1985-01-01

This thesis describes an experiment studying the inclusive reaction hadron + Be → phi + anything → K + + K - + anything in 100 GeV/c, 120 GeV/c and 200 GeV/c hadron interactions. A total of 8x10 6 events were recorded using both positively and negatively charged unseparated hadron beams supplied by the CERN SPS. The experiment made use of an intelligent on-line event selection system based on micro-processors (FAMPs) in conjunction with a system of large MWPCs to increase the number of phi-events recorded per unit time. In 32 days of data taking over 600,000 phi-mesons were recorded onto magnetic tape. The physics motivation for collecting a large statistics sample of inclusive phi-mesons was the investigation of the inclusive phi-meson production mechanism and phi-spectroscopy. (Auth.)

Charmless decays of the B-meson in perturbative QCD

International Nuclear Information System (INIS)

Libo Guo; Dongsheng Du; Lianshou Liu

1999-01-01

Using the perturbative QCD method and Chau's six-quark-graph scheme, we report a theoretical calculation of exclusive nonleptonic decays of the B meson into two light pseudoscalar mesons in the context of the low-energy effective Hamiltonian. The contributions from both tree-level and one-loop diagrams are taken into account. Under the approximation of neglecting light quark and light meson masses, we find that (i) within perturbative QCD there is no singularity which exists in the computation of spacelike penguin diagrams when the BSW model is used; (ii) the contributions from spacelike-type (W-annihilation, W-exchange, spacelike penguin and penguin-annihilation) graphs are strongly suppressed relative to those from timelike-type (external W-emission, internal W-emission and timelike penguin) ones; (iii) our results are well below the experimental upper limits but lower than the BSW ones. (author)

Current status of high energy nucleon-meson transport code

Energy Technology Data Exchange (ETDEWEB)

Takada, Hiroshi; Sasa, Toshinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Current status of design code of accelerator (NMTC/JAERI code), outline of physical model and evaluation of accuracy of code were reported. To evaluate the nuclear performance of accelerator and strong spallation neutron origin, the nuclear reaction between high energy proton and target nuclide and behaviors of various produced particles are necessary. The nuclear design of spallation neutron system used a calculation code system connected the high energy nucleon{center_dot}meson transport code and the neutron{center_dot}photon transport code. NMTC/JAERI is described by the particle evaporation process under consideration of competition reaction of intranuclear cascade and fission process. Particle transport calculation was carried out for proton, neutron, {pi}- and {mu}-meson. To verify and improve accuracy of high energy nucleon-meson transport code, data of spallation and spallation neutron fragment by the integral experiment were collected. (S.Y.)

Lifetime of rho meson in correlation with magnetic-dimensional reduction

Energy Technology Data Exchange (ETDEWEB)

Kawaguchi, Mamiya [Nagoya University, Department of Physics, Nagoya (Japan); Matsuzaki, Shinya [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Institute for Advanced Research, Nagoya (Japan)

2017-04-15

It is naively expected that in a strong magnetic configuration, the Landau quantization ceases the neutral rho meson to decay to the charged pion pair, so the neutral rho meson will be long-lived. To closely access this naive observation, we explicitly compute the charged pion loop in the magnetic field at the one-loop level, to evaluate the magnetic dependence of the lifetime for the neutral rho meson as well as its mass. Due to the dimensional reduction induced by the magnetic field (violation of the Lorentz invariance), the polarization (spin s{sub z} = 0, ±1) modes of the rho meson, as well as the corresponding pole mass and width, are decomposed in a nontrivial manner compared to the vacuum case. To see the significance of the reduction effect, we simply take the lowest Landau level approximation to analyze the spin-dependent rho masses and widths. We find that the ''fate'' of the rho meson may be more complicated because of the magnetic-dimensional reduction: as the magnetic field increases, the rho width for the spin s{sub z} = 0 starts to develop, reaches a peak, then vanishes at the critical magnetic field to which the folklore refers. On the other side, the decay rates of the other rhos for s{sub z} = ±1 monotonically increase as the magnetic field develops. The correlation between the polarization dependence and the Landau level truncation is also addressed. (orig.)

Measurement of the production of K{sup +} mesons by protons in nuclei (1960); Mesure de la production des mesons K{sup +} par des protons dans les noyaux (1960)

Energy Technology Data Exchange (ETDEWEB)

Teiger, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1960-07-01

K{sup +} mesons produced by the internal proton beam of Saturne have been identified by means of scintillation and Cerenkov counters. The production cross sections are given per target nucleus measured at a laboratory angle of 35 deg. as well as the cross section relative to {pi}{sup +} mesons of the same momentum for: - incident protons of kinetic energy between 1.3 and 2.8 GeV, - targets of C, Cu and Pb, - K{sup +} produced with kinetic energies between 0.45 and 0.65 GeV. From these results we have tried to deduce the importance of indirect production by intermediate {pi} mesons with respect to direct production by proton-nucleon collisions. (author) [French] Au moyen de detecteurs a scintillations et a rayonnement Cerenkov, on a identifie les mesons lourds K{sup +} produits par les protons du faisceau interne de 'Saturne'. On donne les sections efficaces de production, par noyau cible, mesurees a 35 deg. dans le laboratoire, ainsi que les sections efficaces relatives par rapport aux mesons {pi}{sup +} de meme impulsion pour: - des protons incidents d'energie cinetique entre 1,3 GeV et 2,8 GeV, - des cibles de C, de Cu et de Pb, - des K{sup +} produits avec des energies cinetiques entre 0,45 et 0,65 GeV. De ces resultats, on a essaye de deduire l'importance de la production indirecte, par mesons {pi} intermediaires, par rapport a la production directe dans un choc proton-nucleon. (auteur)

Quarkonium Contribution to Meson Molecules

Energy Technology Data Exchange (ETDEWEB)

Cincioglu, E.; Yilmazer, A.U. [Ankara University, Department of Physics Engineering, Ankara (Turkey); Nieves, J. [Instituto de Fisica Corpuscular (IFIC) Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigacion de Paterna, Valencia (Spain); Ozpineci, A. [Middle East Technical University, Department of Physics, Ankara (Turkey)

2016-10-15

Starting from a molecular picture for the X(3872) resonance, this state and its J{sup PC} = 2{sup ++} heavy-quark spin symmetry partner [X{sub 2}(4012)] are analyzed within a model which incorporates possible mixings with 2P charmonium (c anti c) states. Since it is reasonable to expect the bare χ{sub c1}(2P) to be located above the D anti D{sup *} threshold, but relatively close to it, the presence of the charmonium state provides an effective attraction that will contribute to binding the X(3872), but it will not appear in the 2{sup ++} sector. Indeed in the latter sector, the χ{sub c2}(2P) should provide an effective small repulsion, because it is placed well below the D{sup *} anti D{sup *} threshold. We show how the 1{sup ++} and 2{sup ++} bare charmonium poles are modified due to the D{sup (*)} anti D{sup (*)} loop effects, and the first one is moved to the complex plane. The meson loops produce, besides some shifts in the masses of the charmonia, a finite width for the 1{sup ++} dressed charmonium state. On the other hand, X(3872) and X{sub 2}(4012) start developing some charmonium content, which is estimated by means of the compositeness Weinberg sum rule. It turns out that in the heavy-quark limit, there is only one coupling between the 2P charmonia and the D{sup (*)} anti D{sup (*)} pairs. We also show that, for reasonable values of this coupling, leading to X(3872) molecular probabilities of around 70-90 %, the X{sub 2} resonance destabilizes and disappears from the spectrum, becoming either a virtual state or one being located deep into the complex plane, with decreasing influence in the D{sup *} anti D{sup *} scattering line. Moreover, we also discuss how around 10-30 % charmonium probability in the X(3872) might explain the ratio of radiative decays of this resonance into ψ(2S)γ and J/ψγ. Finally, we qualitatively discuss within this scheme, the hidden bottom flavor sector, paying a special attention to the implications for the X{sub b} and X

Semileptonic decays of strange beauty mesons at Belle

Energy Technology Data Exchange (ETDEWEB)

Oswald, Christian

2015-06-19

Semileptonic decays of b-flavoured mesons are an important tool for the determination of the CKM matrix element vertical stroke V{sub cb} vertical stroke. In this thesis, measurements of semileptonic B{sub s} meson decays are presented. They provide complementary information to the precision measurements of B meson decays and serve as a test of QCD-calculations predicting SU(3) flavour symmetry for the partial decay widths and form factors. The semi-inclusive and inclusive analyses of semileptonic B{sub s} decays are based on the 121.4 fb{sup -1} dataset collected by the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider in Tsukuba, Japan. The sample recorded at a centre-of-mass energy √(s)=10.86 GeV, which corresponds to the Y(5S) resonance, contains (7.1±1.3) million B{sub s} pair events. To measure the semi-inclusive B{sub s} → D{sub s}Xlν and B{sub s} → D{sub s}{sup *}Xlν branching fractions, D{sub s} and D{sub s}{sup *} candidates are reconstructed and are paired with an oppositely charged lepton, l{sup +}=e{sup +},μ{sup +}. The yields of correctly reconstructed D{sub s} and D{sub s}{sup *} mesons are determined by fits to their respective invariant mass distributions. The signal yield and the yields of the remaining backgrounds are extracted using kinematic distributions of the reconstructed decay products and the constraint from the known initial state of the e{sup +}e{sup -} collision. The measured branching fractions are: B(B{sub s} → D{sub s}Xlν)=(8.2±0.2(stat)±0.6(syst)±1.4(ext)) % and B(B{sub s} → D{sub s}{sup *}lν)=(5.4±0.4(stat)±0.4(syst)±0.9 (ext)) %, where the first two uncertainties are the statistical and systematic uncertainties of the measurement and the last uncertainty is due to external parameters. Making an assumption about the B{sub s} → D{sub s}Xlν branching fraction, the measurement of the B{sub s} → D{sub s}Xlν yield is also used to obtain the current best estimate of the B{sub s} pair

Strange Meson Radiative Capture on the Proton in Low Energy QCD Lagrangian

Institute of Scientific and Technical Information of China (English)

ZHOULi－Juan; MAWei－Xing; 等

2002-01-01

Based on our low energy QCD Lagrangian description of strange meson photoproduction off the proton and the crossing symmetry,the strange meson radiative capture on the proton,K-+p→γ+A,is investigated in the [SU SF(6)×O(3)]sym,SUc(3) quark model of baryon structure with the same input parameter,the only strong coupling constant αM,as that in the strange meson photoproduction off the proton γ+p-→K+ Α，a crossing channel of the capture reaction,A good agreement on the branching ratio between the predictions and data is obtained successfully.This excellent fit indicates that our low energy QCD Lagrangian theory with only one free parameter is an advanced and unified description of strange meson photoproduction and its associated radiative capture.

Meson-baryon coupling constants from a chiral-invariant SU(3) Lagrangian and application to NN scattering

International Nuclear Information System (INIS)

Stoks, V.G.J.

1997-01-01

We present a chiral-invariant meson-baryon Lagrangian which describes the interactions of the baryon octet with the lowest-mass meson nonets. The nonlinear realization of the chiral symmetry generates pair-meson interaction vertices. The corresponding pair-meson coupling constants can all be expressed in terms of the meson-nucleon-nucleon pseudovector, scalar, and vector coupling constants, and their corresponding F/(F+D) ratios, and for which empirical estimates are given. We show that it is possible to construct an NN potential of reasonable quality satisfying these theoretical and empirical constraints. (orig.)

Mass shift of σ-meson in nuclear matter

International Nuclear Information System (INIS)

Morones-Ibarra, J.R.; Maciel, Mónica Menchaca; Padilla, Felipe Robledo; Santos-Guevara, Ayax

2013-01-01

The propagation of σ-meson in nuclear matter is studied in the Walecka model, by assuming that sigma couples to a pair of nucleon-antinucleon states to particle-hole states. The in-medium effect of σ-ω mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the σ-meson mass decreases with respect to its value in vacuum and that the contribution of the σ-ω mixing effect on the mass shift is relatively small. (author)

Radiative decays of the Upsilon(1S) meson

International Nuclear Information System (INIS)

Besson, D.Z.

1986-01-01

Using the CLEO detector at the Cornell Electron Storage Ring, the author is able to measure the QCD scaling parameter Λ/sub MS/ as well as the strong coupling constant α/sub s/ through a measurement of the direct photon energy spectrum resulting from decays of the Upsilon(1S) meson. The author finds fair agreement with previous work. In addition, the author sets limits on exclusive two-body radiative decays of the Upsilon(1S) meson and see no evidence for the type of such two-body decays which are observed in psi decays

Meson thermalization by baryon injection in D4/D6 model

Energy Technology Data Exchange (ETDEWEB)

Rezaei, Z., E-mail: z.rezaei@aut.ac.ir [Department of Physics, Tafresh University, Tafresh 39518 79611 (Iran, Islamic Republic of); School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

2016-12-15

We study meson thermalization in a strongly coupled plasma of quarks and gluons using AdS/CFT duality technique. Four dimensional large-N{sub c} QCD is considered as a theory governing this quark–gluon plasma (QGP) and D4/D6-brane model is chosen to be its holographic dual theory. In order to investigate meson thermalization, we consider a time-dependent change of baryon number chemical potential. Thermalization in gauge theory side corresponds to horizon formation on the probe flavor brane in the gravity side. The gravitational dual theory is compactified on a circle that the inverse of its radius is proportional to energy scale of dual gauge theory. It is seen that increase of this energy scale results in thermalization time dilation. In addition we study the effect of magnetic field on meson thermalization. It will be seen that magnetic field also prolongs thermalization process by making mesons more stable.

Meson thermalization by baryon injection in D4/D6 model

International Nuclear Information System (INIS)

Rezaei, Z.

2016-01-01

We study meson thermalization in a strongly coupled plasma of quarks and gluons using AdS/CFT duality technique. Four dimensional large-N_c QCD is considered as a theory governing this quark–gluon plasma (QGP) and D4/D6-brane model is chosen to be its holographic dual theory. In order to investigate meson thermalization, we consider a time-dependent change of baryon number chemical potential. Thermalization in gauge theory side corresponds to horizon formation on the probe flavor brane in the gravity side. The gravitational dual theory is compactified on a circle that the inverse of its radius is proportional to energy scale of dual gauge theory. It is seen that increase of this energy scale results in thermalization time dilation. In addition we study the effect of magnetic field on meson thermalization. It will be seen that magnetic field also prolongs thermalization process by making mesons more stable.

In-medium properties of pseudoscalar D_s and B_s mesons

Science.gov (United States)

Chhabra, Rahul; Kumar, Arvind

2017-11-01

We calculate the shift in the masses and decay constants of D_s(1968) and B_s(5370) mesons in hot and dense asymmetric strange hadronic matter using QCD sum rules and chiral SU(3) model. In-medium strange quark condensates _{ρ _B}, and gluon condensates _{ρ _B}, to be used in the QCD sum rules for pseudoscalar D_s and B_s mesons, are calculated using a chiral SU(3) model. As an application of our present work, we calculate the in-medium decay widths of the excited (c\\bar{s}) states D_s^*(2715) and D_s^*(2860) decaying to (D_s(1968),η ) mesons. The medium effects in their decay widths are incorporated through the mass modification of the D_s(1968) and η mesons. The results of the present investigation may be helpful in understanding the possible outcomes of the future experiments like CBM and PANDA under the FAIR facility.

Pseudoscalar Meson Electroproduction and Transversity

International Nuclear Information System (INIS)

Goldstein, G.; Liuti, S.

2011-01-01

Exclusive meson leptoproduction from nucleons in the deeply virtual exchanged boson limit can be described by generalized parton distributions (GPDs). Including spin dependence in the description requires 8 independent quark-parton and gluon-parton functions. The chiral even subset of 4 quark-nucleon GPDs are related to nucleon form factors and to parton distribution functions. The chiral odd set of 4 quark-nucleon GPDs are related to transversity, the tensor charge, and other quantities related to transversity. Different meson or photon production processes access different combinations of GPDs. This is analyzed in terms of t-channel exchange quantum numbers, J PC and it is shown that pseudoscalar production can isolate chiral odd GPDs. There is a sensitive dependence in various cross sections and asymmetries on the tensor charge of the nucleon and other transversity parameters. In a second section, analyticity and completeness are shown to limit the partonic interpret ation of the GPDs in the ERBL region.

Decay properties of charm and bottom mesons in a quantum isotonic nonlinear oscillator potential model

Energy Technology Data Exchange (ETDEWEB)

Rahmani, S.; Hassanabadi, H. [Shahrood University of Technology, Physics Department, Shahrood (Iran, Islamic Republic of)

2017-09-15

Employing generalized quantum isotonic oscillator potential we determine wave function for mesonic system in nonrelativistic formalism. Then we investigate branching ratios of leptonic decays for heavy-light mesons including a charm quark. Next, by applying the Isgur-Wise function we obtain branching ratios of semileptonic decays for mesons including a bottom quark. The weak decay of the B{sub c} meson is also analyzed to study the life time. Comparison with other available theoretical approaches is presented. (orig.)

Measurement of the doubly differential cross section for π-p → π+π-n near threshold

International Nuclear Information System (INIS)

Walter, J.B.

1980-05-01

The doubly differential cross sections for the π + from the reaction π - p → π + π - n were measured at about twenty points for each of five energies between 245 MeV and 356 MeV. The experiment was carried out at the Clinton P. Anderson Meson Physics Facility, where a double focusing magnetic spectrometer detected the π + mesons produced in a liquid hydrogen target. The measurements were normalized by comparison with π - p elastic scattering measured with the same apparatus. These are the first such measurements in this energy range, and have an accuracy between 4.7% and 39%. The integrated reaction cross section was determined at each energy with an accuracy of about 5%. These agree with but are an improvement over previous measurements in this energy range. Comparison of the extrapolated threshold value of the mean square modulus of the matrix element with the soft pion calculations favors the symmetry breaking mechanism of Weinberg (xi = 0). It also demonstrates the futility of attempting to determine the symmetry breaking parameter xi from a single measurement of the integrated reaction cross section

Production of excited charm and charm-strange mesons at HERA

Energy Technology Data Exchange (ETDEWEB)

Chekanov, S.; Derrick, M.; Magill, S. [Argonne National Laboratory, Argonne, IL (US)] (and others)

2008-07-15

The production of excited charm, D{sub 1}(2420){sup 0} and D{sup *}{sub 2}(2460){sup 0}, and charm-strange, D{sub s1}(2536){sup {+-}}, mesons in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 126 pb{sup -1}. Masses, widths and helicity parameters were determined. The measured yields were converted to the rates of c quarks hadronising as a given excited charm meson and to the ratios of the dominant D{sup *}{sub 2}(2460){sup 0} and D{sub s1}(2536){sup {+-}} branching fractions. A search for the radially excited charm meson, D{sup *'}(2640){sup {+-}}, was also performed. The results are compared with those measured previously and with theoretical expectations. (orig.)

Photoproduction of vector mesons in proton-proton ultraperipheral collisions at the CERN Large Hadron Collider

Science.gov (United States)

Xie, Ya-Ping; Chen, Xurong

2018-05-01

Photoproduction of vector mesons is computed with dipole model in proton-proton ultraperipheral collisions (UPCs) at the CERN Large Hadron Collider (LHC). The dipole model framework is employed in the calculations of vector mesons production in diffractive processes. Parameters of the bCGC model are refitted with the latest inclusive deep inelastic scattering experimental data. Employing the bCGC model and boosted Gaussian light-cone wave function for vector mesons, we obtain the prediction of rapidity distributions of J/ψ and ψ(2s) mesons in proton-proton ultraperipheral collisions at the LHC. The predictions give a good description of the experimental data of LHCb. Predictions of ϕ and ω mesons are also evaluated in this paper.

Proposal to measure the D meson decay constant F/sub D/

Energy Technology Data Exchange (ETDEWEB)

Deshpande, N.G.; Iskandar, D.

1978-08-01

Because the branching ratios of the purely leptonic modes of D meson are small compared to the semileptonic decays, it is suggested that the decay D ..-->.. K + l + ..nu.. might be used to deduce the value of F/sub D/, the weak decay constant of D meson. 17 references.

New results on Coulomb effects in meson production in relativistic heavy ion collisions

Directory of Open Access Journals (Sweden)

Rybicki Andrzej

2014-01-01

Full Text Available We propose a new method of investigating the space-time evolution of meson production in heavy ion collisions, by making use of spectator-induced electromagnetic (“Coulomb” effects. The presence of two nuclear remnants (“spectator systems” in the non-central collision generates a strong Coulomb field, which modifies the trajectories of charged final state hadrons. This results in charge-dependent azimuthal anisotropies in final state meson emission. In our approach, this effect can be computed numerically by means of a high-statistics Monte Carlo simulation, using the distance between the meson formation zone and the spectator system as free parameter. Our simulation correctly describes the electromagnetic effect on azimuthal anisotropies observed for π+ and π−mesons in Au+Au collisions at lower RHIC energy, known from data recently reported by the STAR Collaboration. Similarly to our earlier studies of spectator-induced electromagnetic effects, also in the present study we find that these effects offer sensitivity to the position of the meson formation zone with respect to the spectator system. Therefore, we conclude that they can serve as a new tool to investigate the space-time evolution of meson production, and the dynamics of the heavy ion collision.

On the mass spectra of the pseudoscalar mesons in the relativistic independent quark model

International Nuclear Information System (INIS)

Khrushchev, V.V.; Semenov, S.V.

2002-01-01

In the framework of the relativistic independent quark model with the QCD-motivated static potential, the masses of the ground states of pseudoscalar mesons and their radial excitations are calculated for both observed mesons and unobserved ones. The strength of the spin-spin interaction and the magnitude of the mean field contribution are estimated for both the light and heavy 0 -+ mesons. The calculated masses are in agreement with experimental values within an accuracy of 30 - 40 MeV, and the predictions are obtained for the mass values of a number of unobserved yet radial excitations of pseudoscalar mesons

Nucleon quark structure and strong meson-nucleon form factors

International Nuclear Information System (INIS)

Efimov, G.V.; Ivanov, M.A.

1987-01-01

The nucleon is considered as a three-quark system in virton-quark model. The main statistic properties of proton and neutron are calculated: magnetic moments, electromagnetic radii, G A /G V ratio in weak neutron decay. Strong meson-nucleon form factors which determine nucleon-nucleon potential are obtained as a function of squared transfer momentum of mesons. The results are compared with phenomenological form factors used for description of phases of NN-scattering in the one-boson-, exchange model

Application of heavy-light methods to B meson physics

International Nuclear Information System (INIS)

Eichten, E.; Hockney, G.; Thacker, H.B.

1989-01-01

The heavy-light method is applied to the study of the B meson spectrum, the pseudoscalar decay constant f B , the mixing (B) parameter, and exclusive semileptonic B meson decays. Preliminary results are discussed for f B and the B parameter at β = 5.7 and κ = 0.165 on a 12 3 x 24 lattice and at β = 5.9 and κ = 0.158 on a 16 3 x 32 lattice. 9 refs., 2 figs., 2 tabs

What Can We Learn from Hadronic and Radiative Decays of Light Mesons?

Science.gov (United States)

Kubis, Bastian

2013-04-01

Chiral perturbation theory offers a powerful tool for the investigation of light pseudoscalar mesons. It incorporates the fundamental symmetries of QCD, interrelates various processes, and allows to link these to the light quark masses. Its shortcomings lie in a limited energy range: the radius of convergence of the chiral expansion is confined to below resonance scales. Furthermore, the strongest consequences of chiral symmetry are manifest for pseudoscalars (pions, kaons, eta) only: vector mesons, e.g., have a severe impact in particular for reactions involving photons. In this talk, I advocate dispersions relations as another model-independent tool to extend the applicability range of chiral perturbation theory. They even allow to tackle the physics of vector mesons in a rigorous way. It will be shown how dispersive methods can be used to resum large rescattering effects, and to provide model-independent links between hadronic and radiative decay modes. Examples to be discussed will include decays of the eta meson, giving access to light-quark-mass ratios or allowing to test the chiral anomaly; and meson transition form factors, which have an important impact on the hadronic light-by-light-scattering contribution to the anomalous magnetic moment of the muon.

Holographic picture of heavy vector meson melting

Energy Technology Data Exchange (ETDEWEB)

Braga, Nelson R.F.; Diles, Saulo [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro, RJ (Brazil); Martin Contreras, Miguel Angel [Universidad de los Andes, High Energy Group, Department of Physics, Bogota (Colombia)

2016-11-15

The fraction of heavy vector mesons produced in a heavy ion collision, as compared to a proton-proton collision, serves as an important indication of the formation of a thermal medium, the quark-gluon plasma. This sort of analysis strongly depends on understanding the thermal effects of a medium like the plasma on the states of heavy mesons. In particular, it is crucial to know the temperature ranges where they undergo a thermal dissociation, or melting. AdS/QCD models are know to provide an important tool for the calculation of hadronic masses, but in general are not consistent with the observation that decay constants of heavy vector mesons decrease with excitation level. It has recently been shown that this problem can be overcome using a soft wall background and introducing an extra energy parameter, through the calculation of correlation functions at a finite position of anti-de Sitter space. This approach leads to the evaluation of masses and decay constants of S wave quarkonium states with just one flavor dependent and one flavor independent parameter. Here we extend this more realistic model to finite temperatures and analyze the thermal behavior of the states 1S, 2S and 3S of bottomonium and charmonium. The corresponding spectral function exhibits a consistent picture for the melting of the states where, for each flavor, the higher excitations melt at lower temperatures. We estimate for these six states the energy ranges in which the heavy vector mesons undergo a transition from a well-defined peak in the spectral function to complete melting in the thermal medium. A very clear distinction between the heavy flavors emerges, with the bottomonium state Υ(1S) surviving a deconfinement transition at temperatures much larger than the critical deconfinement temperature of the medium. (orig.)

Topics on CP violation in B-meson decays

International Nuclear Information System (INIS)

Soares, J.M.

1993-01-01

In this work several independent topics on CP violation in the B-meson decays are addressed. To begin with, the present constraints on the parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix are discussed. Then, I calculate the CP-violating asymmetry in the radiative decays of the charged B-mesons: it only appears at the 2-loop level, but it can be large in the b → dγ decays. At this point, the possibility of using these decays to measure the CKM entry |V td | will be studied. I also consider the decays of the neutral B-mesons: the strong correlation between the asymmetries in B 0 → ΨK S and the B 0 → π + π - is suggested as a powerful test of the standard model (a simple extension of the model is given where the correlation disappears). Finally, I address the question of observing direct CP violation in comparing these two asymmetries. An ambiguity that may arise is resolved due to the role that is played by penguin diagram contributions to the decay amplitudes

Modified quark-meson coupling model for nuclear matter

International Nuclear Information System (INIS)

Jin, X.; Jennings, B.K.

1996-01-01

The quark-meson coupling model for nuclear matter, which describes nuclear matter as nonoverlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons, is modified by introducing medium modification of the bag constant. We model the density dependence of the bag constant in two different ways: One invokes a direct coupling of the bag constant to the scalar meson field, and the other relates the bag constant to the in-medium nucleon mass. Both models feature a decreasing bag constant with increasing density. We find that when the bag constant is significantly reduced in nuclear medium with respect to its free-space value, large canceling isoscalar Lorentz scalar and vector potentials for the nucleon in nuclear matter emerge naturally. Such potentials are comparable to those suggested by relativistic nuclear phenomenology and finite-density QCD sum rules. This suggests that the reduction of bag constant in nuclear medium may play an important role in low- and medium-energy nuclear physics. copyright 1996 The American Physical Society

Proposal for the systematic naming of mesons and baryons

International Nuclear Information System (INIS)

Porter, F.C.; Hernandez, J.J.; Montanet, L.

1984-10-01

Twenty years ago, the Particle Data Group adopted a systematic naming convention for baryons: the symbols N, Δ, Λ, Σ, Ψ, and Ω were to identify the isospin and strangeness, The mesons, by contrast, have become an alphabet soup of uninformative names - theta, iota, xi, zeta, g/sub T/, g/sub s/, H, E, delta, h, g, r, kappa, etc. -, and in some cases identical names are used for mesons with different quantum numbers (A, B, and D). Furthermore, experimentalists are now discovering baryons that contain heavy quarks. It is therefore timely to consider systematic naming conventions both for mesons and for baryons with heavy quarks. The Particle Data Group is circulating this proposal in the hope of generating feedback, and we attach a sheet for responses. It should be emphasized that the Particle Tables would show both the old and new names for some time

Production and interaction of the η meson with nucleons and nuclei

Directory of Open Access Journals (Sweden)

Krzemień Wojciech

2016-01-01

Full Text Available We report on the status of the search for η-mesic nuclei and the studies of the interaction of the η meson with nucleons. Recently we have completed the analysis of the newWASA-at-COSY data on the production of the η meson with polarized proton beam. New results on the analyzing power for the p̄p → ppη reaction with more than an order of magnitude improved precision shed a new light on the production mechanism of the η meson in nucleon-nucleon collisions. Also, the latest results of the search for η-mesic nuclei are discussed.

Non-self-conjugate mesons in a potential model with vacuum-polarization corrections

International Nuclear Information System (INIS)

Barik, N.; Jena, S.N.

1980-01-01

We present a unified approach to the study of non-self-conjugate mesons including both light and heavy mesons in the framework of the vacuum-polarization-corrected flavor-independent potential. We have found that the quark-confining potential in the form of an almost equal admixture of vector and scalar parts successfully explains the S-wave hyperfine levels of the observed light and heavy mesons. Finally we calculate the electromagnetic mass differences of the heavy-quark mesons and obtain (K-bar* 0 -K* - )=3.79 MeV, (K-bar 0 -K - )=6 MeV, (D* + /sub c/-D* 0 /sub c/)=2.4 MeV, (D + /sub c/-D 0 /sub c/)=5.8 MeV, (D* 0 /sub b/-D* - /sub b/)=3.547 MeV, and (D 0 /sub b/-D - /sub b/)=3.558 MeV

A Review on ϕ Meson Production in Heavy-Ion Collision

Directory of Open Access Journals (Sweden)

Md. Nasim

2015-01-01

Full Text Available The main aim of the relativistic heavy-ion experiment is to create extremely hot and dense matter and study the QCD phase structure. With this motivation, experimental program started in the early 1990s at the Brookhaven Alternating Gradient Synchrotron (AGS and the CERN Super Proton Synchrotron (SPS followed by Relativistic Heavy Ion Collider (RHIC at Brookhaven and recently at Large Hadron Collider (LHC at CERN. These experiments allowed us to study the QCD matter from center-of-mass energies (sNN 4.75 GeV to 2.76 TeV. The ϕ meson, due to its unique properties, is considered as a good probe to study the QCD matter created in relativistic collisions. In this paper we present a review on the measurements of ϕ meson production in heavy-ion experiments. Mainly, we discuss the energy dependence of ϕ meson invariant yield and the production mechanism, strangeness enhancement, parton energy loss, and partonic collectivity in nucleus-nucleus collisions. Effect of later stage hadronic rescattering on elliptic flow (v2 of proton is also discussed relative to corresponding effect on ϕ meson v2.

Proposal to measure the D meson decay constant F/sub D/

International Nuclear Information System (INIS)

Deshpande, N.G.; Iskandar, D.

1978-08-01

Because the branching ratios of the purely leptonic modes of D meson are small compared to the semileptonic decays, it is suggested that the decay D → K + l + ν might be used to deduce the value of F/sub D/, the weak decay constant of D meson. 17 references

A massive spinless particle and the unit of length in a spinor geometry

International Nuclear Information System (INIS)

Lynch, J.T.

1999-01-01

The field equations of a spinor geometry are solved for a massive spinless particle. The particle has a composite internal structure, a quantised rest-mass, and a positive-definite and everywhere finite mass density. The particle is stable in isolation, but evidently unstable in the presence of fields due to external sources, such as the electromagnetic fields of particle detectors. On identifying the particle as a neutral meson, the unit of length of the geometry turns out to be approximately 10 -15 m

arXiv Measurement of prompt $D^0$ meson azimuthal anisotropy in PbPb collisions at $\\sqrt{{s}_{NN}}$ = 5.02 TeV

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Sirunyan, Albert M; CMS Collaboration; Adam, Wolfgang; Ambrogi, Federico; Asilar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Grossmann, Johannes; Hrubec, Josef; Jeitler, Manfred; König, Axel; Krammer, Natascha; Krätschmer, Ilse; Liko, Dietrich; Madlener, Thomas; Mikulec, Ivan; Pree, Elias; Rabady, Dinyar; Rad, Navid; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Spanring, Markus; Spitzbart, Daniel; Waltenberger, Wolfgang; Wittmann, Johannes; Wulz, Claudia-Elisabeth; Zarucki, Mateusz; Chekhovsky, Vladimir; Mossolov, Vladimir; Suarez Gonzalez, Juan; De Wolf, Eddi A; Di Croce, Davide; Janssen, Xavier; Lauwers, Jasper; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; De Bruyn, Isabelle; De Clercq, Jarne; Deroover, Kevin; Flouris, Giannis; Lontkovskyi, Denys; Lowette, Steven; Moortgat, Seth; Moreels, Lieselotte; Python, Quentin; Skovpen, Kirill; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Parijs, Isis; Brun, Hugues; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Fasanella, Giuseppe; Favart, Laurent; Goldouzian, Reza; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Luetic, Jelena; Maerschalk, Thierry; Marinov, Andrey; Randle-conde, Aidan; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Vannerom, David; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Cimmino, Anna; Cornelis, Tom; Dobur, Didar; Fagot, Alexis; Gul, Muhammad; Khvastunov, Illia; Poyraz, Deniz; Roskas, Christos; Salva Diblen, Sinem; Tytgat, Michael; Verbeke, Willem; Zaganidis, Nicolas; Bakhshiansohi, Hamed; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; De Visscher, Simon; Delaere, Christophe; Delcourt, Martin; Francois, Brieuc; Giammanco, Andrea; Jafari, Abideh; Komm, Matthias; Krintiras, Georgios; Lemaitre, Vincent; Magitteri, Alessio; 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Iaydjiev, Plamen; Misheva, Milena; Rodozov, Mircho; Shopova, Mariana; Stoykova, Stefka; Sultanov, Georgi; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Fang, Wenxing; Gao, Xuyang; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Chen, Ye; Jiang, Chun-Hua; Leggat, Duncan; Liao, Hongbo; Liu, Zhenan; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Yazgan, Efe; Zhang, Huaqiao; Zhao, Jingzhou; Ban, Yong; Chen, Geng; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; González Hernández, Carlos Felipe; Ruiz Alvarez, José David; Courbon, Benoit; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Sculac, Toni; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Ferencek, Dinko; Kadija, Kreso; Mesic, Benjamin; Starodumov, Andrei; Susa, Tatjana; Ather, Mohsan Waseem; 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Lopez-Fernandez, Ricardo; Mejia Guisao, Jhovanny; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Oropeza Barrera, Cristina; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Uribe Estrada, Cecilia; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Saddique, Asif; Shah, Mehar Ali; Shoaib, Muhammad; Waqas, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bozena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Pyskir, Andrzej; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Nemallapudi, Mythra Varun; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Voytishin, Nikolay; Zarubin, Anatoli; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Stepennov, Anton; Toms, Maria; Vlasov, Evgueni; Zhokin, Alexander; Aushev, Tagir; Bylinkin, Alexander; Chadeeva, Marina; Parygin, Pavel; Philippov, Dmitry; Polikarpov, Sergey; Popova, Elena; Rusinov, Vladimir; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Terkulov, Adel; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Ershov, Alexander; Gribushin, Andrey; Kaminskiy, Alexandre; Kodolova, Olga; Korotkikh, Vladimir; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Vardanyan, Irina; Blinov, Vladimir; Skovpen, Yuri; Shtol, Dmitry; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Elumakhov, Dmitry; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Cirkovic, Predrag; Devetak, Damir; Dordevic, Milos; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Barrio Luna, Mar; Cerrada, Marcos; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; Álvarez Fernández, Adrian; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Cuevas, Javier; Erice, Carlos; Fernandez Menendez, Javier; Gonzalez Caballero, Isidro; González Fernández, Juan Rodrigo; Palencia Cortezon, Enrique; Sanchez Cruz, Sergio; Suárez Andrés, Ignacio; Vischia, Pietro; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Chazin Quero, Barbara; Curras, Esteban; Duarte Campderros, Jordi; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Martinez Rivero, Celso; Martinez Ruiz del Arbol, Pablo; Matorras, Francisco; Piedra Gomez, Jonatan; Rodrigo, Teresa; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolò; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Baillon, Paul; Ball, Austin; Barney, David; Bianco, Michele; Bloch, Philippe; Bocci, Andrea; Botta, Cristina; Camporesi, Tiziano; Castello, Roberto; Cepeda, Maria; Cerminara, Gianluca; Chapon, Emilien; Chen, Yi; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Roeck, Albert; Di Marco, Emanuele; Dobson, Marc; Dorney, Brian; Du Pree, Tristan; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Everaerts, Pieter; Franzoni, Giovanni; Fulcher, Jonathan; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Glege, Frank; Gulhan, Doga; Gundacker, Stefan; Guthoff, Moritz; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Karacheban, Olena; Kieseler, Jan; Kirschenmann, Henning; Knünz, Valentin; Kornmayer, Andreas; Kortelainen, Matti J; Krammer, Manfred; Lange, Clemens; Lecoq, Paul; Lourenco, Carlos; Lucchini, Marco Toliman; Malgeri, Luca; Mannelli, Marcello; Martelli, Arabella; Meijers, Frans; Merlin, Jeremie Alexandre; Mersi, Stefano; Meschi, Emilio; Milenovic, Predrag; Moortgat, Filip; Mulders, Martijn; Neugebauer, Hannes; Orfanelli, Styliani; Orsini, Luciano; Pape, Luc; Perez, Emmanuel; Peruzzi, Marco; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Racz, Attila; Reis, Thomas; Rolandi, Gigi; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Seidel, Markus; Selvaggi, Michele; Sharma, Archana; Silva, Pedro; Sphicas, Paraskevas; Stakia, Anna; Steggemann, Jan; Stoye, Markus; Tosi, Mia; Treille, Daniel; Triossi, Andrea; Tsirou, Andromachi; Veckalns, Viesturs; Veres, Gabor Istvan; Verweij, Marta; Wardle, Nicholas; Zeuner, Wolfram Dietrich; Bertl, Willi; Caminada, Lea; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Rohe, Tilman; Wiederkehr, Stephan Albert; Bachmair, Felix; Bäni, Lukas; Berger, Pirmin; Bianchini, Lorenzo; Casal, Bruno; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Grab, Christoph; Heidegger, Constantin; Hits, Dmitry; Hoss, Jan; Kasieczka, Gregor; Klijnsma, Thomas; Lustermann, Werner; Mangano, Boris; Marionneau, Matthieu; Meinhard, Maren Tabea; Meister, Daniel; Micheli, Francesco; Musella, Pasquale; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pata, Joosep; Pauss, Felicitas; Perrin, Gaël; Perrozzi, Luca; Quittnat, Milena; Reichmann, Michael; Schönenberger, Myriam; Shchutska, Lesya; Tavolaro, Vittorio Raoul; Theofilatos, Konstantinos; Vesterbacka Olsson, Minna Leonora; Wallny, Rainer; Zhu, De Hua; Aarrestad, Thea Klaeboe; Amsler, Claude; Canelli, Maria Florencia; De Cosa, Annapaola; Del Burgo, Riccardo; Donato, Silvio; Galloni, Camilla; Hreus, Tomas; Kilminster, Benjamin; Ngadiuba, Jennifer; Pinna, Deborah; Rauco, Giorgia; Robmann, Peter; Salerno, Daniel; Seitz, Claudia; Takahashi, Yuta; Zucchetta, Alberto; Candelise, Vieri; Doan, Thi Hien; Jain, Shilpi; Khurana, Raman; Kuo, Chia-Ming; Lin, Willis; Pozdnyakov, Andrey; Yu, Shin-Shan; Kumar, Arun; Chang, Paoti; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Fiori, Francesco; Hou, George Wei-Shu; Hsiung, Yee; Liu, Yueh-Feng; Lu, Rong-Shyang; Paganis, Efstathios; Psallidas, Andreas; Steen, Arnaud; Tsai, Jui-fa; Asavapibhop, Burin; Kovitanggoon, Kittikul; Singh, Gurpreet; Srimanobhas, Norraphat; Adiguzel, Aytul; Boran, Fatma; Cerci, Salim; Damarseckin, Serdal; Demiroglu, Zuhal Seyma; Dozen, Candan; Dumanoglu, Isa; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Hos, Ilknur; Kangal, Evrim Ersin; Kara, Ozgun; Kayis Topaksu, Aysel; Kiminsu, Ugur; Oglakci, Mehmet; Onengut, Gulsen; Ozdemir, Kadri; Sunar Cerci, Deniz; Tali, Bayram; Turkcapar, Semra; Zorbakir, Ibrahim Soner; Zorbilmez, Caglar; Bilin, Bugra; Karapinar, Guler; Ocalan, Kadir; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Tekten, Sevgi; Yetkin, Elif Asli; Nazlim Agaras, Merve; Atay, Serhat; Cakir, Altan; Cankocak, Kerem; Grynyov, Boris; Levchuk, Leonid; Sorokin, Pavel; Aggleton, Robin; Ball, Fionn; Beck, Lana; Brooke, James John; Burns, Douglas; Clement, Emyr; Cussans, David; Davignon, Olivier; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Sakuma, Tai; Seif El Nasr-storey, Sarah; Smith, Dominic; Smith, Vincent J; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Calligaris, Luigi; Cieri, Davide; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Williams, Thomas; Auzinger, Georg; Bainbridge, Robert; Breeze, Shane; Buchmuller, Oliver; Bundock, Aaron; Casasso, Stefano; Citron, Matthew; Colling, David; Corpe, Louie; Dauncey, Paul; Davies, Gavin; De Wit, Adinda; Della Negra, Michel; Di Maria, Riccardo; Elwood, Adam; Haddad, Yacine; Hall, Geoffrey; Iles, Gregory; James, Thomas; Lane, Rebecca; Laner, Christian; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Mastrolorenzo, Luca; Matsushita, Takashi; Nash, Jordan; Nikitenko, Alexander; Palladino, Vito; Pesaresi, Mark; Raymond, David Mark; Richards, Alexander; Rose, Andrew; Scott, Edward; Seez, Christopher; Shtipliyski, Antoni; Summers, Sioni; Tapper, Alexander; Uchida, Kirika; Vazquez Acosta, Monica; Virdee, Tejinder; Winterbottom, Daniel; Wright, Jack; Zenz, Seth Conrad; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Borzou, Ahmad; Call, Kenneth; Dittmann, Jay; Hatakeyama, Kenichi; Liu, Hongxuan; Pastika, Nathaniel; Smith, Caleb; Bartek, Rachel; Dominguez, Aaron; Buccilli, Andrew; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; West, Christopher; Arcaro, Daniel; Avetisyan, Aram; Bose, Tulika; Gastler, Daniel; Rankin, Dylan; Richardson, Clint; Rohlf, James; Sulak, Lawrence; Zou, David; Benelli, Gabriele; Cutts, David; Garabedian, Alex; Hakala, John; Heintz, Ulrich; Hogan, Julie Managan; Kwok, Ka Hei Martin; Laird, Edward; Landsberg, Greg; Mao, Zaixing; Narain, Meenakshi; Pazzini, Jacopo; Piperov, Stefan; Sagir, Sinan; Syarif, Rizki; Yu, David; Band, Reyer; Brainerd, Christopher; Burns, Dustin; Calderon De La Barca Sanchez, Manuel; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Flores, Chad; Funk, Garrett; Gardner, Michael; Ko, Winston; Lander, Richard; Mclean, Christine; Mulhearn, Michael; Pellett, Dave; Pilot, Justin; Shalhout, Shalhout; Shi, Mengyao; Smith, John; Squires, Michael; Stolp, Dustin; Tos, Kyle; Tripathi, Mani; Wang, Zhangqier; Bachtis, Michail; Bravo, Cameron; Cousins, Robert; Dasgupta, Abhigyan; Florent, Alice; Hauser, Jay; Ignatenko, Mikhail; Mccoll, Nickolas; Saltzberg, David; Schnaible, Christian; Valuev, Vyacheslav; Bouvier, Elvire; Burt, Kira; Clare, Robert; Ellison, John Anthony; Gary, J William; Ghiasi Shirazi, Seyyed Mohammad Amin; Hanson, Gail; Heilman, Jesse; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Long, Owen Rosser; Olmedo Negrete, Manuel; Paneva, Mirena Ivova; Shrinivas, Amithabh; Si, Weinan; Wang, Long; Wei, Hua; Wimpenny, Stephen; Yates, Brent; Branson, James G; Cittolin, Sergio; Derdzinski, Mark; Gerosa, Raffaele; Hashemi, Bobak; Holzner, André; Klein, Daniel; Kole, Gouranga; Krutelyov, Vyacheslav; Letts, James; Macneill, Ian; Masciovecchio, Mario; Olivito, Dominick; Padhi, Sanjay; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tadel, Matevz; Vartak, Adish; Wasserbaech, Steven; Wood, John; Würthwein, Frank; Yagil, Avraham; Zevi Della Porta, Giovanni; Amin, Nick; Bhandari, Rohan; Bradmiller-Feld, John; Campagnari, Claudio; Dishaw, Adam; Dutta, Valentina; Franco Sevilla, Manuel; George, Christopher; Golf, Frank; Gouskos, Loukas; Gran, Jason; Heller, Ryan; Incandela, Joe; Mullin, Sam Daniel; Ovcharova, Ana; Qu, Huilin; Richman, Jeffrey; Stuart, David; Suarez, Indara; Yoo, Jaehyeok; Anderson, Dustin; Bendavid, Joshua; Bornheim, Adolf; Lawhorn, Jay Mathew; Newman, Harvey B; Nguyen, Thong; Pena, Cristian; Spiropulu, Maria; Vlimant, Jean-Roch; Xie, Si; Zhang, Zhicai; Zhu, Ren-Yuan; Andrews, Michael Benjamin; Ferguson, Thomas; Mudholkar, Tanmay; Paulini, Manfred; Russ, James; Sun, Menglei; Vogel, Helmut; Vorobiev, Igor; Weinberg, Marc; Cumalat, John Perry; Ford, William T; Jensen, Frank; Johnson, Andrew; Krohn, Michael; Leontsinis, Stefanos; Mulholland, Troy; Stenson, Kevin; Wagner, Stephen Robert; Alexander, James; Chaves, Jorge; Chu, Jennifer; Dittmer, Susan; Mcdermott, Kevin; Mirman, Nathan; Patterson, Juliet Ritchie; Rinkevicius, Aurelijus; Ryd, Anders; Skinnari, Louise; Soffi, Livia; Tan, Shao Min; Tao, Zhengcheng; Thom, Julia; Tucker, Jordan; Wittich, Peter; Zientek, Margaret; Abdullin, Salavat; Albrow, Michael; Apollinari, Giorgio; Apresyan, Artur; Apyan, Aram; Banerjee, Sunanda; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Canepa, Anadi; Cerati, Giuseppe Benedetto; Cheung, Harry; Chlebana, Frank; Cremonesi, Matteo; Duarte, Javier; Elvira, Victor Daniel; Freeman, Jim; Gecse, Zoltan; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kreis, Benjamin; Lammel, Stephan; Lincoln, Don; Lipton, Ron; Liu, Miaoyuan; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Magini, Nicolo; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mrenna, Stephen; Nahn, Steve; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Ristori, Luciano; Schneider, Basil; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Stoynev, Stoyan; Strait, James; Strobbe, Nadja; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Wang, Michael; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Brinkerhoff, Andrew; Carnes, Andrew; Carver, Matthew; Curry, David; Field, Richard D; Furic, Ivan-Kresimir; Konigsberg, Jacobo; Korytov, Andrey; Kotov, Khristian; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Mitselmakher, Guenakh; Rank, Douglas; Sperka, David; Terentyev, Nikolay; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Joshi, Yagya Raj; Linn, Stephan; Markowitz, Pete; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Todd; Askew, Andrew; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Kolberg, Ted; Martinez, German; Perry, Thomas; Prosper, Harrison; Saha, Anirban; Santra, Arka; Yohay, Rachel; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Cavanaugh, Richard; Chen, Xuan; Evdokimov, Olga; Gerber, Cecilia Elena; Hangal, Dhanush Anil; Hofman, David Jonathan; Jung, Kurt; Kamin, Jason; Sandoval Gonzalez, Irving Daniel; Tonjes, Marguerite; Trauger, Hallie; Varelas, Nikos; Wang, Hui; Wu, Zhenbin; Zhang, Jingyu; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Blumenfeld, Barry; Cocoros, Alice; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Roskes, Jeffrey; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; You, Can; Al-bataineh, Ayman; Baringer, Philip; Bean, Alice; Boren, Samuel; Bowen, James; Castle, James; Khalil, Sadia; Kropivnitskaya, Anna; Majumder, Devdatta; Mcbrayer, William; Murray, Michael; Royon, Christophe; Sanders, Stephen; Schmitz, Erich; Stringer, Robert; Tapia Takaki, Daniel; Wang, Quan; Ivanov, Andrew; Kaadze, Ketino; Maravin, Yurii; Mohammadi, Abdollah; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Toda, Sachiko; Rebassoo, Finn; Wright, Douglas; Anelli, Christopher; Baden, Drew; Baron, Owen; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Ferraioli, Charles; Hadley, Nicholas John; Jabeen, Shabnam; Jeng, Geng-Yuan; Kellogg, Richard G; Kunkle, Joshua; Mignerey, Alice; Ricci-Tam, Francesca; Shin, Young Ho; Skuja, Andris; Tonwar, Suresh C; Abercrombie, Daniel; Allen, Brandon; Azzolini, Virginia; Barbieri, Richard; Baty, Austin; Bi, Ran; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; D'Alfonso, Mariarosaria; Demiragli, Zeynep; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hsu, Dylan; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Maier, Benedikt; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Tatar, Kaya; Velicanu, Dragos; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Benvenuti, Alberto; Chatterjee, Rajdeep Mohan; Evans, Andrew; Hansen, Peter; Kalafut, Sean; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Claes, Daniel R; Fangmeier, Caleb; Gonzalez Suarez, Rebeca; Kamalieddin, Rami; Kravchenko, Ilya; Monroy, Jose; Siado, Joaquin Emilo; Snow, Gregory R; Stieger, Benjamin; Alyari, Maral; Dolen, James; Godshalk, Andrew; Harrington, Charles; Iashvili, Ia; Nguyen, Duong; Parker, Ashley; Rappoccio, Salvatore; Roozbahani, Bahareh; Alverson, George; Barberis, Emanuela; Hortiangtham, Apichart; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Teixeira De Lima, Rafael; Trocino, Daniele; Wood, Darien; Bhattacharya, Saptaparna; Charaf, Otman; Hahn, Kristan Allan; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Schmitt, Michael Henry; Sung, Kevin; Trovato, Marco; Velasco, Mayda; Dev, Nabarun; Hildreth, Michael; Hurtado Anampa, Kenyi; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Loukas, Nikitas; Marinelli, Nancy; Meng, Fanbo; Mueller, Charles; Musienko, Yuri; Planer, Michael; Reinsvold, Allison; Ruchti, Randy; Smith, Geoffrey; Taroni, Silvia; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Alimena, Juliette; Antonelli, Louis; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Francis, Brian; Hart, Andrew; Hill, Christopher; Ji, Weifeng; Liu, Bingxuan; Luo, Wuming; Puigh, Darren; Winer, Brian L; Wulsin, Howard Wells; Benaglia, Andrea; Cooperstein, Stephane; Driga, Olga; Elmer, Peter; Hardenbrook, Joshua; Hebda, Philip; Higginbotham, Samuel; Lange, David; Luo, Jingyu; Marlow, Daniel; Mei, Kelvin; Ojalvo, Isabel; Olsen, James; Palmer, Christopher; Piroué, Pierre; Stickland, David; Tully, Christopher; Malik, Sudhir; Norberg, Scarlet; Barker, Anthony; Barnes, Virgil E; Das, Souvik; Folgueras, Santiago; Gutay, Laszlo; Jha, Manoj; Jones, Matthew; Jung, Andreas Werner; Khatiwada, Ajeeta; Miller, David Harry; Neumeister, Norbert; Peng, Cheng-Chieh; Qiu, Hao; Schulte, Jan-Frederik; Sun, Jian; Wang, Fuqiang; Xie, Wei; Cheng, Tongguang; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Chen, Zhenyu; Ecklund, Karl Matthew; Geurts, Frank JM; Guilbaud, Maxime; Li, Wei; Michlin, Benjamin; Northup, Michael; Padley, Brian Paul; Roberts, Jay; Rorie, Jamal; Tu, Zhoudunming; Zabel, James; Bodek, Arie; de Barbaro, Pawel; Demina, Regina; Duh, Yi-ting; Ferbel, Thomas; Galanti, Mario; Garcia-Bellido, Aran; Han, Jiyeon; Hindrichs, Otto; Khukhunaishvili, Aleko; Lo, Kin Ho; Tan, Ping; Verzetti, Mauro; Ciesielski, Robert; Goulianos, Konstantin; Mesropian, Christina; Agapitos, Antonis; Chou, John Paul; Gershtein, Yuri; Gómez Espinosa, Tirso Alejandro; Halkiadakis, Eva; Heindl, Maximilian; Hughes, Elliot; Kaplan, Steven; Kunnawalkam Elayavalli, Raghav; Kyriacou, Savvas; Lath, Amitabh; Montalvo, Roy; Nash, Kevin; Osherson, Marc; Saka, Halil; Salur, Sevil; Schnetzer, Steve; Sheffield, David; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Delannoy, Andrés G; Foerster, Mark; Heideman, Joseph; Riley, Grant; Rose, Keith; Spanier, Stefan; Thapa, Krishna; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Celik, Ali; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Huang, Tao; Kamon, Teruki; Mueller, Ryan; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Perniè, Luca; Rathjens, Denis; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Damgov, Jordan; De Guio, Federico; Dudero, Phillip Russell; Faulkner, James; Gurpinar, Emine; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Libeiro, Terence; Peltola, Timo; Undleeb, Sonaina; Volobouev, Igor; Wang, Zhixing; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Melo, Andrew; Ni, Hong; Sheldon, Paul; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Barria, Patrizia; Cox, Bradley; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Xia, Fan; Harr, Robert; Karchin, Paul Edmund; Sturdy, Jared; Zaleski, Shawn; Brodski, Michael; Buchanan, James; Caillol, Cécile; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Herndon, Matthew; Hervé, Alain; Hussain, Usama; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Pierro, Giuseppe Antonio; Polese, Giovanni; Ruggles, Tyler; Savin, Alexander; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel

2018-05-17

The prompt D0 meson azimuthal anisotropy coefficients, v2 and v3, are measured at midrapidity (|y|<1.0) in Pb-Pb collisions at a center-of-mass energy sNN=5.02  TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (pT) range of 1 to 40  GeV/c, for central and midcentral collisions. The v2 coefficient is found to be positive throughout the pT range studied. The first measurement of the prompt D0 meson v3 coefficient is performed, and values up to 0.07 are observed for pT around 4  GeV/c. Compared to measurements of charged particles, a similar pT dependence, but smaller magnitude for pT<6  GeV/c, is found for prompt D0 meson v2 and v3 coefficients. The results are consistent with the presence of collective motion of charm quarks at low pT and a path length dependence of charm quark energy loss at high pT, thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark...

Meson decays in a quark model

International Nuclear Information System (INIS)

Roberts, W.; Silvestre-Brac, B.

1998-01-01

A recent model of hadron states is extended to include meson decays. We find that the overall success of the model is quite good. Possible improvements to the model are suggested. copyright 1997 The American Physical Society

New physics effects from meson decays

Indian Academy of Sciences (India)

beyond the Standard Model from -meson decays, taking К-parity conserving and violating super- symmetry .... particular choice of the parameter space, can be much higher than the SM ones. .... CLEO has already given some food for thought.

Inclusive vector meson production and hadron structure

International Nuclear Information System (INIS)

Boeckmann, K.

1977-08-01

It is shown that J/PSI production in hadronic interactions is dominated by central production from sea quarks even at beam momenta as low as 40 GeV/c. All known experimental data on inclusive vector meson production support the hypothesis that cross sections obtained from meson-nucleon and nucleon-nucleon interactions have to be compared in the quark C.M. system. With the distinction of sea quark and valence quark interactions in the additive quark model a consistent description of inclusive rho, K*, PHI and J/PSI production in hadronic interactions. A natural connection of inclusive rho 0 production cross sections in anti pp, pp and πp interactions is obtained. (orig.) [de

A transverse lattice QCD model for mesons

Energy Technology Data Exchange (ETDEWEB)

Patel, Apoorva D.; Ratabole, Raghunath

2004-03-01

QCD is analysed with two light-front continuum dimensions and two transverse lattice dimensions. In the limit of large number of colours and strong transverse gauge coupling, the contributions of light-front and transverse directions factorise in the dynamics, and the theory can be analytically solved in a closed form. An integral equation is obtained, describing the properties of mesons, which generalises the 't Hooft equation by including spin degrees of freedom. The meson spectrum, light-front wavefunctions and form factors can be obtained by solving this equation numerically. These results would be a good starting point to model QCD observables which only weakly depend on transverse directions, e.g. deep inelastic scattering structure functions.

Charmed meson production by e+e- annihilation

International Nuclear Information System (INIS)

Wiss, J.E.

1977-08-01

Compelling evidence is presented for the production of the lying (D 0 , D + ) isodoublet of charmed mesons by e + e - annihilation. A study of the recoil mass spectra against these mesons reveals the presence of more massive charmed states, the D* 0 and D* + , produced in association with the D isodoublet. Mass values and upper limits on the width of the D and D* are established, and the branching fractions for several D* decay modes are obtained. An analysis of the production and decay angular distributions shows that the D is probably a pseudoscalar state and the D* is probably a vector. Finally, upper limits are obtained for D 0 -antiD 0 mixing

Observation of orbitally excited B(s) mesons.

Science.gov (United States)

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Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; 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Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

2008-02-29

We report the observation of two narrow resonances consistent with states of orbitally excited (L=1) B_(s) mesons using 1 fb;(-1) of pp[over ] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II detector at the Fermilab Tevatron. We use two-body decays into K- and B+ mesons reconstructed as B(+)-->J/psiK(+), J/psi-->mu(+)mu(-) or B(+)-->D[over ](0)pi(+), D[over ](0)-->K(+)pi(-). We deduce the masses of the two states to be m(B_(s1))=5829.4+/-0.7 MeV/c(2) and m(B_(s2);(*))=5839.6+/-0.7 MeV/c;(2).

Universal behavior in excited heavy-light and light-light mesons

International Nuclear Information System (INIS)

Olsson, M.G.

1997-01-01

A common pattern of large orbital and radial excitations in heavy-light and light-light mesons is demonstrated. For a general potential model with linear confinement the Regge slopes of the light degrees of freedom for these mesons are shown to be in the ratio of 2. The possibility of 'tower' degeneracy occurs only with pure scalar confinement. copyright 1997 The American Physical Society

Pion physics at the meson factories

International Nuclear Information System (INIS)

Nagle, D.E.; Johnson, M.B.; Measday, D.F.

1987-01-01

Pi meson probes have contributed much to our ideas about how neutrons and protons are distributed and move relative to each other in nuclei, and along with other probes, to our understanding of basic symmetries in particle physics

Two-body spectra of pseudoscalar mesons with an O(a2)-improved lattice action using Wilson fermions

International Nuclear Information System (INIS)

Fiebig, H.R.; Mihaly, A.; Woloshyn, R.M.

1998-01-01

We extend our calculations with the second-order tree-level and tadpole improved next-nearest-neighbor action to meson-meson systems. Correlation matrices built from interpolating fields representing two pseudoscalar mesons (π-π) with relative momenta vector-p are diagonalized, and the mass spectrum is extracted. Link variable fuzzing and operator smearing at both sinks and sources is employed. Calculations are presented for two values of the hopping parameter. The spectrum is used to discuss the residual interaction in the meson-meson system. (orig.)

Effects of pump recycling technique on stimulated Brillouin scattering threshold: a theoretical model.

Science.gov (United States)

Al-Asadi, H A; Al-Mansoori, M H; Ajiya, M; Hitam, S; Saripan, M I; Mahdi, M A

2010-10-11

We develop a theoretical model that can be used to predict stimulated Brillouin scattering (SBS) threshold in optical fibers that arises through the effect of Brillouin pump recycling technique. Obtained simulation results from our model are in close agreement with our experimental results. The developed model utilizes single mode optical fiber of different lengths as the Brillouin gain media. For 5-km long single mode fiber, the calculated threshold power for SBS is about 16 mW for conventional technique. This value is reduced to about 8 mW when the residual Brillouin pump is recycled at the end of the fiber. The decrement of SBS threshold is due to longer interaction lengths between Brillouin pump and Stokes wave.

Search for Bc+ decays to two charm mesons

Directory of Open Access Journals (Sweden)

R. Aaij

2018-05-01

Full Text Available A search for decays of Bc+ mesons to two charm mesons is performed for the first time using data corresponding to an integrated luminosity of 3.0fb−1, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV. The decays considered are Bc+→D(s(⁎+D‾(⁎0 and Bc+→D(s(⁎+D(⁎0, which are normalised to high-yield B+→D(s+D‾0 decays. No evidence for a signal is found and limits are set on twelve Bc+ decay modes.