Oset, E; Sun, Bao Xi; Vacas, M J Vicente; Ramos, A; Gonzalez, P; Vijande, J; Torres, A Martinez; Khemchandani, K
2009-01-01
In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the $\\Lambda(1405)$ resonance, as well as the prediction of one $1/2^+$ baryon state around 1920 MeV which might have been seen in the $\\gamma p \\to K^+ \\Lambda$ reaction.
Energy Technology Data Exchange (ETDEWEB)
Oset, E. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Sarkar, S. [Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064 (India); Sun Baoxi [Institute of Theoretical Physics, College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Vicente Vacas, M.J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Ramos, A. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, 08028 Barcelona (Spain); Gonzalez, P. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Vijande, J. [Departamento de Fisica Atomica Molecular y Nuclear and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Martinez Torres, A. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Khemchandani, K. [Centro de Fisica Computacional, Departamento de Fisica, Universidade de Coimbra, P-3004-516 Coimbra (Portugal)
2010-04-01
In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the {lambda}(1405) resonance, as well as the prediction of one 1/2{sup +} baryon state around 1920 MeV which might have been seen in the {gamma}p{yields}K{sup +}{lambda} reaction.
Baryon Spectroscopy and Resonances
Energy Technology Data Exchange (ETDEWEB)
Robert Edwards
2011-12-01
A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of
Progress Toward Understanding Baryon Resonances
Crede, Volker
2013-01-01
The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1-2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and pions. After decades of research, the fundamental degrees of freedom underlying the baryon excitation spectrum are still poorly understood. The search for hitherto undiscovered but predicted resonances continues at many laboratories around the world. Recent results from photo- and electroproduction experiments provide intriguing indications for new states and shed light on the structure of some of the known nucleon excitations. The continuing study of available data sets with consideration of new observables and improved analysis tools have also called into question some of the earlier findings in baryon spectroscopy. Other breakthrough measurements have be...
Algebraic model of baryon resonances
Bijker, R
1997-01-01
We discuss recent calculations of electromagnetic form factors and strong decay widths of nucleon and delta resonances. The calculations are done in a collective constituent model of the nucleon, in which the baryons are interpreted as rotations and vibrations of an oblate top.
Directory of Open Access Journals (Sweden)
Downie E.J.
2014-06-01
Full Text Available The quest to understand the physics of any system cannot be said to be complete as long as one cannot predict and fully understand its resonance spectrum. Despite this, due to the experimental challenge of the required double polarization measurements and the difficulty in achieving unambiguous, model-independent extraction and interpretation of the nucleon resonance spectrum of many broad and overlapping resonances, understanding of the structure and dynamics of the nucleon has suffered. The recent improvement in statistical quality and kinematic range of the data made available by such full-solid-angle systems as the CB and TAPS constellation at MAMI, coupled with the high flux polarized photon beam provided by the Glasgow Photon Tagger, and the excellent properties of the Mainz Frozen Spin Target, when paired with new developments in Partial Wave Analysis (PWA methodology make this a very exciting and fruitful time in nucleon resonance studies. Here the recent influx of data and PWA developments are summarized, and the requirements for a complete, unambiguous PWA solution over the first and second resonance region are briefly reviewed.
Meson Production and Baryon Resonances at CLAS
Energy Technology Data Exchange (ETDEWEB)
Volker Burkert
2011-02-01
I give a brief overview of the exploration of baryon properties in meson photo- and electroproduction. These processes provide ample information for the study of electromagnetic couplings of baryon resonances and to search for states, yet to be discovered. The CLAS detector, combined with the use of energy-tagged polarized photons and polarized electrons, as well as polarized targets and the measurement of recoil polarization, provide the tools for a comprehensive nucleon resonance program. I briefly present the status of this program, prospects for the next few years, and plans for the Jefferson Lab 12 GeV upgrade.
Exotic baryon resonances in the Skyrme model
Diakonov, Dmitri
2008-01-01
We outline how one can understand the Skyrme model from the modern perspective. We review the quantization of the SU(3) rotations of the Skyrmion, leading to the exotic baryons that cannot be made of three quarks. It is shown that in the limit of large number of colours the lowest-mass exotic baryons can be studied from the kaon-Skyrmion scattering amplitudes, an approach known after Callan and Klebanov. We follow this approach and find, both analytically and numerically, a strong Theta+ resonance in the scattering amplitude that is traced to the rotational mode. The Skyrme model does predict an exotic resonance Theta+ but grossly overestimates the width. To understand better the factors affecting the width, it is computed by several methods giving, however, identical results. In particular, we show that insofar as the width is small, it can be found from the transition axial constant. The physics leading to a narrow Theta+ resonance is briefly reviewed and affirmed.
Strong decays of baryons and missing resonances
Bijker, R.; Ferretti, J.; Galatà, G.; García-Tecocoatzi, H.; Santopinto, E.
2016-10-01
We provide results for the open-flavor strong decays of strange and nonstrange baryons into a baryon-vector/pseudoscalar meson pair. The decay amplitudes are computed in the 3P0 pair-creation model, where s s ¯ pair-creation suppression is included for the first time in the baryon sector, in combination with the U (7 ) and hypercentral models. The effects of this s s ¯ suppression mechanism cannot be reabsorbed in a redefinition of the model parameters or in a different choice of the 3P0 model vertex factor. Our results for the decay amplitudes are compared with the existing experimental data and previous 3P0 and elementary meson emission model calculations. In this respect, we show that distinct quark models differ in the number of missing resonances they predict and also in the quantum numbers of states. Therefore, future experimental results will be important in order to disentangle different models of baryon structure. Finally, in the appendixes, we provide some details of our calculations, including the derivation of all relevant flavor couplings with strangeness suppression. This derivation may be helpful to calculate the open-flavor decay amplitudes starting from other models of baryons.
Electromagnetic properties of baryon resonances
Tiator, Lothar
2012-01-01
Longitudinal and transverse transition form factors for most of the four-star nucleon resonances have been obtained from high-quality cross section data and polarization observables measured at MAMI, ELSA, BATES, GRAAL and CEBAF. As an application, we further show how the transition form factors can be used to obtain empirical transverse charge densities. Contour plots of the thus derived densities are shown and compared for the Roper and S11 nucleon resonances.
Quark-mass dependence of baryon resonances
Energy Technology Data Exchange (ETDEWEB)
Lutz, M.F.M. [Gesellschaft fuer Schwerionenforschung (GSI), Planck Str. 1, D-64291 Darmstadt (Germany) and Institut fuer Kernphysik, TU Darmstadt, D-64289 Darmstadt (Germany)]. E-mail: m.lutz@gsi.de; Garcia-Recio, C. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain); Kolomeitsev, E.E. [Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark); Nieves, J. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)
2005-05-30
We study the quark-mass dependence of JP=12- s-wave and JP=32- d-wave baryon resonances. Parameter-free results are obtained in terms of the leading order chiral Lagrangian. In the 'heavy' SU(3) limit with m{pi}=mK{approx}500 MeV the s-wave resonances turn into bound states forming two octets plus a singlet representations of the SU(3) group. Similarly the d-wave resonances turn into bound states forming an octet and a decuplet in this limit. A contrasted result is obtained in the 'light' SU(3) limit with m{pi}=mK{approx}140 MeV for which no resonances exist.
Observation of Two New Xi(-)(b) Baryon Resonances
Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Akiba, K. Carvalho; Casanova Mohr, R. C. M.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C. -T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Domenico, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. -M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gastaldi, U.; Gauld, R.; Gavardi, L.; Gazzoni, U.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Graciani Diaz, R.; Cardoso, L. A. Granado; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griftith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lowdon, P.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Benito, C. Mann; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Santos, D. Martinez; Vidal, F. Martinez; Martin Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. -N.; Moggi, N.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. -B.; Mountain, R.; Muheim, F.; Mueller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obratsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Orlandea, M.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. -H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Sena, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Sheychenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; Van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Vazquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Barbosa, J. V. V. B. Viana; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; de Vries, J. A.; Wraldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M. P.; Williams, M.; Wilschut, H. W.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyae, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.
2015-01-01
Two structures are observed close to the kinematic threshold in the Xi(0)(b)pi(-) mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LEICb experiment. In the quark model, two baryonic resonances with quark content bds a
Time delayed K sup + N reactions and exotic baryon resonances
Kelkar, N G; Khemchandani, K P
2003-01-01
Evidence and hints, from both the theoretical and experimental sides, of exotic baryon resonances with B = S, have been with us for the last 30 years. The poor status of the general acceptance of these Z* resonances is partly due to the prejudice against penta-quark baryons and partly due to the opinion that a proof of the existence of exotic states must be rigorous. This can refer to the quality and amount of data gathered, and also to the analytical methods applied in the study of these resonances. It then seems mandatory that all possibilities and aspects be exploited. We do that by analysing the time delay in K sup + N scattering, encountering clear signals of the exotic Z* resonances close to the pole values found in partial wave analyses.
Electroproduction of Baryon Resonances and Strangeness Suppression
Santopinto, E; Tecocoatzi, H Garcia
2016-01-01
We describe the electroproduction ratios of baryon-meson states from nucleon using an extension of the quark model that takes into account the sea. As a result we provide, with no adjustable parameters, the predictions of ratios of exclusive meson-baryon final states: Lambda K , Sigma K, p pion, and n pion. These predictions are in agreement with the new Jlab experimental data showing that sea quarks play an important role in the electroproduction. We also predicted further ratios of exclusive reactions that can be measured and tested in future experiments. In particular, we suggested new experiments on deuterium and tritium. Such measurements can provide crucial test of different predictions concerning the structure of nucleon and its sea quarks helping to solve an outstanding problem. Finally, we computed the so called strangeness suppression factor, lambda s, that is the suppression of strange quark-antiquarks compared to nonstrange pairs, and we found that our finding with this simple extension of the qua...
Chiral dynamics of S-wave baryon resonances
Long, Bingwei
2015-01-01
As the pion mass approaches a critical value $m_\\pi^\\star$ from below, an $S$-wave resonance crosses pion-baryon threshold and becomes a bound state with arbitrarily small binding energy, thus driving the scattering length to diverge. I explore the consequences of chiral symmetry for the values of $m_\\pi$ close to $m_\\pi^\\star$. It turns out that chiral symmetry is crucial for an $S$-wave resonance to be able to stand very near threshold and in the meantime to remain narrow, provided that the mass splitting is reasonably small. The effective range of pion-baryon scattering is unexpectedly large, proportional to $ 4\\pi f_\\pi^2/m_\\pi^3$ when $m_\\pi$ is around $m_\\pi^\\star$. As a result, this unexpected large length scale causes universality relations to break down much sooner than naively expected.
Quark mass dependence of s-wave baryon resonances
Energy Technology Data Exchange (ETDEWEB)
Garcia-Recio, C.; Nieves, J. [Granada Univ. (Spain). Dept. de Fisica Moderna; Lutz, M.F.M. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)
2003-06-01
We study the quark mass dependence of J{sup P} = 1/2{sup -} s-wave baryon resonances. Parameter free results are obtained in terms of the leading order chiral Lagrangian. In the 'heavy' SU(3) limit with m{sub {pi}} = m{sub K} {approx_equal} 500 MeV the resonances turn into bound states forming two octets plus a singlet representations of the SU(3) group. A contrasted result is obtained in the 'light' SU(3) limit with m{sub {pi}} = m{sub K} {approx_equal} 140 MeV for which no resonances exist. Using physical quark masses our analysis suggests to assign to the S = -2 resonances {xi}(1690) and {xi}(1620) the quantum numbers J{sup P} = 1/2{sup -}. (orig.)
Recent Progress in Understanding the Baryon Resonance Spectrum
Crede, Volker
2017-01-01
Baryons are complex systems of confined quarks and gluons and exhibit the characteristic spectra of excited states. These states are sensitive to the details of quark confinement, which is only poorly understood with quantum chromodynamics (QCD), the fundamental theory of the strong interaction. To gain insight into this complex dynamics, the baryonic excitation spectrum has been studied for many years. The key question remains what are the relevant degrees of freedom for the resonance physics of QCD. Are the so-called constituent quarks the most efficient way to describe reaction amplitudes and the excitation spectrum of QCD with light quarks? To what extent are diquark correlations, gluonic modes or hadronic degrees of freedom important in this physics? In recent years, lattice-QCD has made significant progress toward understanding the spectra of hadrons, reducing statistical uncertainties and employing robust techniques for spin identication. However, a calculation of the physical excited baryon spectrum is still a tough challenge with present computing power. On the experimental side, high-energy electrons and photons are a remarkably clean probe of hadronic matter, providing a microscope for examining atomic nuclei and the strong nuclear force. Significant progress has been achieved with the recent availability of new polarization data, utilizing polarized beams and/or polarized targets at various laboratories worldwide, e.g. Jefferson Lab in the United States. These are important steps toward so-called complete experiments that will allow us to unambiguously determine the scattering amplitudes in the underlying reactions and to identify resonance contributions. In this presentation, I will give an overview of the excited baryon program and I will discuss the current (experimental) status of the nucleon excitation spectrum. Support is acknowledged from the Department of Energy grant #DE-FG02-92ER40735.
Baryon resonances from a novel fat-link fermion action
Melnitchouk, W; Bonnet, F D R; Coddington, P D; Leinweber, D B; Williams, A G; Zanotti, J M; Zhang, J B; Lee, F X
2002-01-01
We present first results for masses of positive and negative parity excited baryons in lattice QCD using an O(a^2) improved gluon action and a Fat Link Irrelevant Clover (FLIC) fermion action in which only the irrelevant operators are constructed with fat links. The results are in agreement with earlier calculations of N^* resonances using improved actions and exhibit a clear mass splitting between the nucleon and its chiral partner, even for the Wilson fermion action. The results also indicate a splitting between the lowest J^P = 1/2^- states for the two standard nucleon interpolating fields.
Baryon resonances without quarks: A chiral soliton perspective
Energy Technology Data Exchange (ETDEWEB)
Karliner, M.
1987-03-01
In many processes involving low momentum transfer it is fruitful to regard the nucleon as a soliton or ''monopole-like'' configuration of the pion field. In particular, within this framework it is possible to obtain detailed predictions for pion-nucleon scattering amplitudes and for properties of baryon resonances. One can also derive model-independent linear relations between scattering amplitudes, such as ..pi..N and anti KN. A short survey of some recent results is given, including comparison with experimental data.
Baryonic Resonances Mass Spectrum from a Modified Perturbative QCD
Cabo-Montes de Oca, Alejandro; Oca, Alejandro Cabo Montes de; Madrazo, Marcos Rigol
2001-01-01
A recently proposed modified perturbation expansion for QCD incorporating gluon condensation effects is employed to evaluate the quark self-energy in the simplest approximation. One of the solutions of the modified mass shell predicts mass values which increases monotonically with the corresponding Lagrangian mass for each kind of flavour. The mass spectrum of the ground states within the various groups of hadronic resonances and a class of mesonic ones is well predicted by the simple addition of the calculated constituent quark masses. These results suggest the gluon condensate nature of many baryonic resonances and the possibility of their description by a modified perturbative theory. Finally, it is conjectured that this procedure, after also introducing quark condensates in a same token as the gluonic ones, could predict the Lagrangian quark masses as well as the non-colored fermion (leptons and neutrinos) mass spectrum, through higher order radiative correction. Such a picture, if verified, would furnish...
Observation of two new Ξ(b)(-) baryon resonances.
Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bertolin, A; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casanova Mohr, R C M; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Dean, C-T; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Di Domenico, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H-M; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farley, N; Farry, S; Fay, R; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fol, P; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gastaldi, U; Gauld, R; Gavardi, L; Gazzoni, G; Geraci, A; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gianì, S; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Hess, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Lohn, S; Longstaff, I; Lopes, J H; Lowdon, P; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Mapelli, A; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J
2015-02-13
Two structures are observed close to the kinematic threshold in the Ξ(b)(0)π(-) mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content bds are expected in this mass region: the spin-parity J(P)=(1/2)(+) and J(P)=(3/2)(+) states, denoted Ξ(b)('-) and Ξ(b)(*-). Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be m(Ξ(b)('-))-m(Ξ(b)(0))-m(π(-))=3.653±0.018±0.006 MeV/c(2), m(Ξ(b)(*-))-m(Ξ(b)(0))-m(π(-))=23.96±0.12±0.06 MeV/c(2), Γ(Ξ(b)(*-))=1.65±0.31±0.10 MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of Γ(Ξ(b)('-))<0.08 MeV at 95% confidence level. Relative production rates of these states are also reported.
Observation of two new $\\Xi_b^-$ baryon resonances
Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casanova Mohr, Raimon; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew Christopher; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Domenico, Antonio; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Sterpka, Christopher Francis; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang
2015-01-01
Two structures are observed close to the kinematic threshold in the $\\Xi_b^0\\pi^-$ mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content $bds$ are expected in this mass region: the spin-parity $J^P = \\frac{1}{2}^+$ and $J^P=\\frac{3}{2}^+$ states, denoted $\\Xi_b^{\\prime -}$ and $\\Xi_b^{*-}$. Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be \\begin{eqnarray*} m(\\Xi_b^{\\prime -}) - m(\\Xi_b^0) - m(\\pi^{-}) &=& 3.653 \\pm 0.018 \\pm 0.006~{\\rm MeV}/c^2, \\\\ m(\\Xi_b^{*-}) - m(\\Xi_b^0) - m(\\pi^{-}) &=& 23.96 \\pm 0.12\\pm 0.06~{\\rm MeV}/c^2, \\\\ \\Gamma(\\Xi_b^{*-}) &=& 1.65 \\pm 0.31 \\pm 0.10~{\\rm MeV}, \\end{eqnarray*} where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place ...
Dynamically generated resonances from the vector octet-baryon decuplet interaction
Energy Technology Data Exchange (ETDEWEB)
Sarkar, Sourav [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica e IFIC, Valencia (Spain); Variable Energy Cyclotron Centre, Bidhannagar, Kolkata (India); Sun, Bao-Xi [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica e IFIC, Valencia (Spain); Beijing University of Technology, Institute of Theoretical Physics, College of Applied Sciences, Beijing (China); Oset, E.; Vicente Vacas, M.J. [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica e IFIC, Valencia (Spain)
2010-06-15
We study the interaction of the octet of vector mesons with the decuplet of baryons using Lagrangians of the hidden gauge theory for vector interactions. The unitary amplitudes in coupled channels develop poles that can be associated with some known baryonic resonances, while there are predictions for new ones at the energy frontier of the experimental research. The work offers guidelines on how to search for these resonances. (orig.)
Dynamically generated resonances from the vector octet-baryon decuplet interaction
Sarkar, Sourav; Oset, E; Vacas, M J Vicente
2009-01-01
We study the interaction of the octet of vector mesons with the decuplet of baryons using Lagrangians of the hidden gauge theory for vector interactions. The unitary amplitudes in coupled channels develop poles that can be associated with some known baryonic resonances, while there are predictions for new ones at the energy frontier of the experimental research. The work offers guidelines on how to search for these resonances.
Baryon resonances in the mean field approach and a simple explanation of the Theta+ pentaquark
Diakonov, Dmitri
2008-01-01
We suggest to classify baryon resonances as single-quark states in a mean field, and/or as its collective excitations. Identifying the Roper resonance N(1440), the nucleon resonance N(1535), and the singlet hyperon Lambda(1405) as single-quark excitations, we find that there must be an exotic S=+1 baryon resonance Theta+ (the "pentaquark") with a mass about 1440+1535-1405=1570 MeV and spin-parity one-half-plus. We argue that Theta+ is an analog of the Gamov--Teller excitation long known in nuclear physics.
Dynamically generated resonances from the interaction of vector mesons with baryons
Oset, E; Vacas, M J Vicente; Ramos, A; Vijande, J; Sarkar, S; Sun, Bao Xi
2009-01-01
We present the results of the first calculations involving the interaction of vector mesons with baryons, by means of which one generates a large amount of dynamically generated resonances, many of which can be associated to known resonances, while others represent predictions for new states.
Strange baryonic resonances and resonances coupling to strange hadrons at SIS energies
Energy Technology Data Exchange (ETDEWEB)
Fabbietti, L. [e12, Physik Department Technische Universität München Excellence Cluster “Origin and Structure of the Universe” (Germany)
2016-01-22
The role played by baryonic resonances in the production of final states containing strangeness for proton-proton reactions at 3.5 GeV measured by HADES is discussed by means of several very different measurements. First the associate production of Δ resonances accompanying final states with strange hadrons is presented, then the role of interferences among N{sup *} resonances, as measured by HADES for the first time, is summarised. Last but not least the role played by heavy resonances, with a mass larger than 2 GeV/c{sup 2} in the production of strange and non-strange hadrons is discussed. Experimental evidence for the presence of a Δ(2000){sup ++} are presented and hypotheses are discussed employing the contribution of similar objects to populate the excesses measured by HADES for the Ξ in A+A and p+A collisions and in the dilepton sector for A+A collisions. This extensive set of results helps to better understand the dynamic underlaying particle production in elementary reactions and sets a more solid basis for the understanding of heavy ion collisions at the same energies and even higher as planned at the FAIR facility.
Yao, De-Liang; Siemens, D.; Bernard, V.; Epelbaum, E.; Gasparyan, A. M.; Gegelia, J.; Krebs, H.; Meißner, Ulf-G.
2016-05-01
We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz invariant formulation of baryon chiral perturbation theory using dimensional regularization and the extended on-mass-shell renormalization scheme. In the delta resonance sector, the on mass-shell renormalization is realized as a complex-mass scheme. By fitting the low-energy constants of the effective Lagrangian to the S- and P -partial waves a satisfactory description of the phase shifts from the analysis of the Roy-Steiner equations is obtained. We predict the phase shifts for the D and F waves and compare them with the results of the analysis of the George Washington University group. The threshold parameters are calculated both in the delta-less and delta-full cases. Based on the determined low-energy constants, we discuss the pion-nucleon sigma term. Additionally, in order to determine the strangeness content of the nucleon, we calculate the octet baryon masses in the presence of decuplet resonances up to next-to-next-to-leading order in SU(3) baryon chiral perturbation theory. The octet baryon sigma terms are predicted as a byproduct of this calculation.
Hadron resonance gas and mean-field nuclear matter for baryon number fluctuations
Fukushima, Kenji
2014-01-01
We give an estimate for the skewness and the kurtosis of the baryon number distribution in two representative models; i.e., models for a hadron resonance gas and relativistic mean-field nuclear matter. We emphasize formal similarity between these two descriptions. The hadron resonance gas leads to a deviation from the Skellam distribution if quantum statistical correlation is taken into account at high baryon density, but this effect is not strong enough to explain fluctuation data seen in the beam-energy scan at RHIC/STAR. In the calculation of mean-field nuclear matter the density correlation with the vector \\omega-field rather than the effective mass with the scalar \\sigma-field renders the kurtosis suppressed at higher baryon density so as to account for the observed behavior of the kurtosis. We finally discuss the difference between the baryon number and the proton number fluctuations from correlation effects in isospin space. Our numerical results suggest that such effects are only minor even in the cas...
Cumulative production of pions by heavy baryonic resonances in proton-nucleus collisions
Motornenko, A.; Gorenstein, M. I.
2017-02-01
Pion production in proton-nucleus (p+A) collisions outside the kinematical boundary of proton-nucleon (p+N) reactions and the so-called cumulative effect are studied. Restrictions from energy-momentum conservation of the energy of pions emitted in the backward direction in the target rest frame are analyzed. It is assumed that the cumulative pions are produced in p+A reactions by heavy baryonic resonances. The baryonic resonances are first created in p+N reactions. Due to successive collisions with nuclear nucleons, the masses of these resonances may then increase and, simultaneously, their longitudinal velocities decrease. We also use the ultra relativistic quantum molecular dynamics model to reveal the key role of successive collisions of baryonic resonances with nuclear nucleons for cumulative pion production in p+A reactions. Further experimental studies of cumulative hadron production in p+A reactions at high collision energies are needed to search for heavy hadron-like objects and investigate their properties.
Chiral dynamics of baryon resonances and hadrons in a nuclear medium
Indian Academy of Sciences (India)
E Oset; D Cabrera; V K Magas; L Roca; S Sarkar; M J Vicente Vacas; A Ramos
2006-04-01
In these lectures I make an introduction to chiral unitary theory applied to the meson-baryon interaction and show how several well-known resonances are dynamically generated, and others are predicted. Two very recent experiments are analyzed, one of them showing the existence of two (1405) states and the other one providing support for the (1520) resonance as a quasi-bound state of $\\sum (1385) $. The use of chiral Lagrangians to account for the hadronic interaction at the elementary level introduces a new approach to deal with the modification of meson and baryon properties in a nuclear medium. Examples of it for $\\bar{K}$, and modification in the nuclear medium are presented.
Scattering phases for meson and baryon resonances on general moving-frame lattices
Göckeler, M; Lage, M; Meissner, U -G; Rakow, P E L; Rusetsky, A; Schierholz, G; Zanotti, J M
2012-01-01
A proposal by L\\"uscher enables one to compute the scattering phases of elastic two-body systems from the energy levels of the lattice Hamiltonian in a finite volume. In this work we generalize the formalism to S--, P-- and D--wave meson and baryon resonances, and general total momenta. Employing nonvanishing momenta has several advantages, among them making a wider range of energy levels accessible on a single lattice volume and shifting the level crossing to smaller values of $m_\\pi L$.
Formation of a narrow baryon resonance with positive strangeness in K^+ collisions with Xe nuclei
Barmin, V V; Borisov, V S; Curceanu, C; Davidenko, G V; Dolgolenko, A G; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tumanov, G K; Verebryusov, V S
2009-01-01
The data on the charge-exchange reaction K^+Xe --> K^0 p Xe, obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK^0 resonance with mass near 1538 MeV is confirmed and reinforced. The statistical significance of the signal reaches some 8\\sigma (6\\sigma) when estimated as S/\\sqrt{B} (S/\\sqrt{B+S}). The mass and intrinsic width of the \\Theta^+ baryon are measured as m = (1538+-2) MeV and \\Gamma = (0.39+-0.10) MeV.
On kinematical constraints in the hadrogenesis conjecture for the baryon resonance spectrum
Heo, Yonggoo
2014-01-01
We consider the reaction dynamics of bosons with negative parity and spin $0$ or $1$ and fermions with positive parity and spin $\\frac{1}{2}$ or $\\frac{3}{2}$. Such systems are of central importance for the computation of the baryon resonance spectrum in the hadrogenesis conjecture. Based on a chiral Lagrangian the coupled-channel partial-wave scattering amplitudes have to be computed. We study the generic properties of such amplitudes. A decomposition of the various scattering amplitudes into suitable sets of invariant functions expected to satisfy Mandelstam's dispersion-integral representation is presented. Sets are identified that are free from kinematical constraints and that can be computed efficiently in terms of a novel projection algebra. From such a representation one can deduce the analytic structure of the partial-wave amplitudes. The helicity and the conventional angular-momentum partial-wave amplitudes are kinematically constrained at the Kibble conditions. Therefore an application of a dispersi...
Decays of Baryon Resonances into K Lambda, K^+ Sigma^0 and K^0 Sigma^+
Sarantsev, A V; Anisovich, A V; Klempt, E; Thoma, U
2005-01-01
Cross sections, beam asymmetries, and recoil polarisations for the reactions gamma p to K^+ Lambda ; gamma to K^+ Sigma^0, and gamma p to K^0 Sigma^+ have been measured by the SAPHIR, CLAS, and LEPS collaborations with high statistics and good angular coverage for centre-of-mass energies between 1.6 and 2.3 GeV. The combined analysis of these data with data from pi and eta photoproduction reveals evidence for new baryon resonances in this energy region. A new P_{11} state with mass 1840 MeV and width 140 MeV was observed contributing to most of the fitted reactions. The data demand the presence of two D_{13} states at 1870 and 2170 MeV.
Baryon resonance production and dielectron decays in proton-proton collisions at 3.5 GeV
Energy Technology Data Exchange (ETDEWEB)
Agakishiev, G.; Belyaev, A.; Chernenko, S.; Fateev, O.; Ierusalimov, A.; Ladygin, V.; Vasiliev, T.; Zanevsky, Y. [Joint Institute of Nuclear Research, Dubna (Russian Federation); Balanda, A.; Dybczak, A.; Michalska, B.; Palka, M.; Przygoda, W.; Salabura, P.; Trebacz, R. [Jagiellonian University of Cracow, Smoluchowski Institute of Physics, Krakow (Poland); Belver, D.; Cabanelas, P.; Garzon, J.A. [Univ. de Santiago de Compostela, LabCAF. F. Fisica, Santiago de Compostela (Spain); Berger-Chen, J.C.; Epple, E.; Fabbietti, L.; Lalik, R.; Lapidus, K.; Siebenson, J. [Excellence Cluster ' ' Origin and Structure of the Universe' ' , Garching (Germany); Blanco, A.; Fonte, P.; Lopes, L.; Mangiarotti, A. [LIP-Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Coimbra (Portugal); Boehmer, M.; Friese, J.; Gernhaeuser, R.; Jurkovic, M.; Kruecken, R.; Maier, L.; Weber, M. [Technische Universitaet Muenchen, Physik Department E12, Garching (Germany); Boyard, J.L.; Hennino, T.; Liu, T.; Ramstein, B. [Universite Paris Sud, Institut de Physique Nucleaire (UMR 8608), CNRS/IN2P3, Orsay Cedex (France); Finocchiaro, P.; Schmah, A.; Spataro, S. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Froehlich, I.; Goebel, K.; Lorenz, M.; Markert, J.; Michel, J.; Muentz, C.; Pachmayer, Y.C.; Pechenova, O.; Rustamov, A.; Stroebele, H.; Tarantola, A.; Teilab, K. [Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt (Germany); Galatyuk, T.; Gonzalez-Diaz, D.; Gumberidze, M.; Kornakov, G. [Technische Universitaet Darmstadt, Darmstadt (Germany); Golubeva, M.; Guber, F.; Ivashkin, A.; Karavicheva, T.; Kurepin, A.; Reshetin, A.; Sadovsky, A. [Russian Academy of Science, Institute for Nuclear Research, Moscow (Russian Federation); Heinz, T.; Holzmann, R.; Koenig, I.; Koenig, W.; Kolb, B.W.; Lang, S.; Pechenov, V.; Pietraszko, J.; Schwab, E.; Sturm, C.; Traxler, M.; Yurevich, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Iori, I. [Sezione di Milano, INFN, Milano (Italy); Kaempfer, B.; Kotte, R.; Naumann, L.; Wendisch, C.; Wuestenfeld, J. [Institut fuer Strahlenphysik, Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Krasa, A.; Krizek, F.; Kugler, A.; Sobolev, Yu.G.; Tlusty, P.; Wagner, V. [Academy of Sciences of Czech Republic, Nuclear Physics Institute, Rez (Czech Republic); Kuc, H. [Jagiellonian University of Cracow, Smoluchowski Institute of Physics, Krakow (Poland); Universite Paris Sud, Institut de Physique Nucleaire (UMR 8608), CNRS/IN2P3, Orsay Cedex (France); Kuehn, W.; Metag, V.; Spruck, B. [Justus Liebig Universitaet Giessen, II.Physikalisches Institut, Giessen (Germany); Lebedev, A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Parpottas, Y.; Tsertos, H. [University of Cyprus, Department of Physics, Nicosia (Cyprus); Stroth, J. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt (Germany)
2014-05-15
We report on baryon resonance production and decay in proton-proton collisions at a kinetic energy of 3.5 GeV based on data measured with HADES. The exclusive channels pp → npπ{sup +} and pp → ppπ{sup 0} as well as pp → ppe{sup +}e{sup -} are studied simultaneously for the first time. The invariant masses and angular distributions of the pion-nucleon systems were studied and compared to simulations based on a resonance model ansatz assuming saturation of the pion production by an incoherent sum of baryonic resonances (R) with masses < 2 GeV/c{sup 2}. A very good description of the one-pion production is achieved allowing for an estimate of individual baryon resonance production cross sections which are used as input to calculate the dielectron yields from R → pe{sup +}e{sup -} decays. Two models of the resonance decays into dielectrons are examined assuming a point-like RNγ{sup *} coupling and the dominance of the ρ meson. The results of model calculations are compared to data from the exclusive ppe{sup +}e{sup -} channel by means of the dielectron and pe{sup +}e{sup -} invariant mass distributions. (orig.)
Baryon resonance production and dielectron decays in proton-proton collisions at 3.5 GeV
Agakishiev, G; Belver, D; Belyaev, A; Berger-Chen, J C; Blanco, A; Böhmer, M; Boyard, J L; Cabanelas, P; Chernenko, S; Dybczak, A; Epple, E; Fabbietti, L; Fateev, O; Finocchiaro, P; Fonte, P; Friese, J; Fröhlich, I; Galatyuk, T; Garzón, J A; Gernhäuser, R; Göbel, K; Golubeva, M; González-Díaz, D; Guber, F; Gumberidze, M; Heinz, T; Hennino, T; Holzmann, R; Ierusalimov, A; Iori, I; Ivashkin, A; Jurkovic, M; Kämpfer, B; Karavicheva, T; König, I; König, W; Kolb, B W; Kornakov, G; Kotte, R; Krása, A; Krizek, F; Krücken, R; Kuc, H; Kühn, W; Kugler, A; Kurepin, A; Ladygin, V; Lalik, R; Lang, S; Lapidus, K; Lebedev, A; Liu, T; Lopes, L; Lorenz, M; Maier, L; Mangiarotti, A; Markert, J; Metag, V; Michalska-Trebacz, B; Michel, J; Müntz, C; Naumann, L; Pachmayer, Y C; Pa\\lka, M; Parpottas, Y; Pechenov, V; Pechenova, O; Pietraszko, J; Przygoda, W; Ramstein, B; Reshetin, A; Rustamov, A; Sadovsky, A; Salabura, P; Schmah, A; Schwab, E; Siebenson, J; Sobolev, Yu G; Spataro, S; Spruck, B; Ströbele, H; Stroth, J; Sturm, C; Tarantola, A; Teilab, K; Tlusty, P; Traxler, M; Trebacz, R; Tsertos, H; Vasiliev, T; Wagner, V; Weber, M; Wendisch, C; Wüstenfeld, J; Yurevich, S; Zanevsky, Y
2014-01-01
We report on baryon resonance production and decay in proton-proton collisions at a kinetic energy of $3.5$ GeV based on data measured with HADES. The exclusive channels $pp \\rightarrow np\\pi^{+}$ and $pp \\rightarrow pp\\pi^{0}$ as well as $pp \\rightarrow ppe^{+}e^{-}$ are studied simultaneously for the first time. The invariant masses and angular distributions of the pion-nucleon systems were studied and compared to simulations based on a resonance model ansatz assuming saturation of the pion production by an incoherent sum of baryonic resonances (R) with masses $<2~$ GeV/$c^2$. A very good description of the one-pion production is achieved allowing for an estimate of individual baryon-resonance production-cross-sections which are used as input to calculate the dielectron yields from $R\\rightarrow pe^+e^-$ decays. Two models of the resonance decays into dielectrons are examined assuming a point-like $RN \\gamma^*$ coupling and the dominance of the $\\rho$ meson. The results of model calculations are compared...
Yao, De-Liang; Bernard, V; Epelbaum, E; Gasparyan, A M; Gegelia, J; Krebs, H; Meißner, Ulf-G
2016-01-01
We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz invariant formulation of baryon chiral perturbation theory using dimensional regularization and the extended on-mass-shell renormalization scheme. In the delta resonance sector, the on mass-shell renormalization is realized as a complex-mass scheme. By fitting the low-energy constants of the effective Lagrangian to the $S$- and $P$-partial waves a satisfactory description of the phase shifts from the analysis of the Roy-Steiner equations is obtained. We predict the phase shifts for the $D$ and $F$ waves and compare them with the results of the analysis of the George Washington University group. The threshold parameters are calculated both in the delta-less and delta-full cases. Based on the determined low-energy constants, we discuss the pion-nucleon sigma term. Additionally, in ...
The ep -->e'p eta reaction at and above the S11(1535) baryon resonance.
Thompson, R; Dytman, S; Kim, K Y; Mueller, J; Adams, G S; Amaryan, M J; Anciant, E; Anghinolfi, M; Asavapibhop, B; Auger, T; Audit, G; Avakian, H; Barrow, S; Battaglieri, M; Beard, K; Bektasoglu, M; Bertozzi, W; Bianchi, N; Biselli, A; Boiarinov, S; Bonner, B E; Briscoe, W J; Brooks, W; Burkert, V D; Calarco, J R; Capitani, G; Carman, D S; Carnahan, B; Cole, P L; Coleman, A; Connelly, J; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J; Day, D; Degtyarenko, P V; Demirchyan, R A; Dennis, L C; Deppman, A; De Sanctis, E; De Vita, R; Dhuga, K S; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Eckhause, M; Efremenko, Y V; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Farhi, L; Feuerbach, R J; Ficenec, J; Fissum, K; Freyberger, A; Funsten, H; Gai, M; Gavrilov, V B; Gilfoyle, G P; Giovanetti, K; Gilad, S; Girard, P; Griffioen, K A; Guidal, M; Guillo, M; Gyurjyan, V; Hancock, D; Hardie, J; Heddle, D; Heisenberg, J; Hersman, F W; Hicks, K; Hicks, R S; Holtrop, M; Hyde-Wright, C E; Ito, M M; Jenkins, D; Joo, K; Kane, J; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klusman, M; Kossov, M; Kuhn, S E; Kuang, Y; Laget, J M; Lawrence, D; Leskin, G A; Longhi, A; Loukachine, K; Lucas, M; Magahiz, R; Major, R W; Manak, J J; Marchand, C; Matthews, S K; McAleer, S; McCarthy, J; McNabb, J W; Mecking, B A; Mestayer, M D; Meyer, C A; Minehart, R; Mirazita, M; Miskimen, R; Muccifora, V; Mutchler, G S; Napolitano, J; Niyazov, R A; Ohandjanyan, M S; O'Brien, J T; Opper, A; Patois, Y; Peterson, G A; Philips, S; Pivnyuk, N; Pocanic, D; Pogorelko, O; Polli, E; Preedom, B M; Price, J W; Qin, L M; Raue, B A; Reolon, A R; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rossi, P; Roudot, F; Rowntree, D; Rubin, P D; Salgado, C W; Sanzone, M; Sapunenko, V; Sarty, A; Sargsyan, M; Schumacher, R A; Shafi, A; Sharabian, Y G; Shaw, J; Shuvalov, S M; Skabelin, A; Smith, T; Smith, C; Smith, E S; Sober, D I; Spraker, M; Stepanyan, S; Stoler, P; Taiuti, M; Taylor, S; Tedeschi, D; Tung, T Y; Vineyard, M F; Vlassov, A; Weller, H; Weinstein, L B; Welsh, R; Weygand, D P; Whisnant, S; Witkowski, M; Wolin, E; Yegneswaran, A; Yun, J; Zhou, Z; Zhao, J
2001-02-26
New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.
On kinematical constraints in the hadrogenesis conjecture for the baryon resonance spectrum
Energy Technology Data Exchange (ETDEWEB)
Heo, Yonggoo; Lutz, Matthias F.M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)
2014-08-15
We consider the reaction dynamics of bosons with negative parity and spin 0 or 1 and fermions with positive parity and spin (1)/(2) or (3)/(2). Such systems are of central importance for the computation of the baryon resonance spectrum in the hadrogenesis conjecture. Based on a chiral Lagrangian the coupled-channel partial-wave scattering amplitudes have to be computed. We study the generic properties of such amplitudes. A decomposition of the various scattering amplitudes into suitable sets of invariant functions expected to satisfy Mandelstam's dispersion-integral representation is presented. Sets are identified that are free from kinematical constraints and that can be computed efficiently in terms of a novel projection algebra. From such a representation one can deduce the analytic structure of the partial-wave amplitudes. The helicity and the conventional angular-momentum partial-wave amplitudes are kinematically constrained at the Kibble conditions. Therefore an application of a dispersion-integral representation is prohibitively cumbersome. We derive covariant partial-wave amplitudes that are free from kinematical constraints at the Kibble conditions. They correspond to specific polynomials in the 4-momenta and Dirac matrices that solve the various Bethe-Salpeter equations in the presence of short-range interactions analytically. (orig.)
On kinematical constraints in the hadrogenesis conjecture for the baryon resonance spectrum
Heo, Yonggoo; Lutz, Matthias F. M.
2014-08-01
We consider the reaction dynamics of bosons with negative parity and spin 0 or 1 and fermions with positive parity and spin or . Such systems are of central importance for the computation of the baryon resonance spectrum in the hadrogenesis conjecture. Based on a chiral Lagrangian the coupled-channel partial-wave scattering amplitudes have to be computed. We study the generic properties of such amplitudes. A decomposition of the various scattering amplitudes into suitable sets of invariant functions expected to satisfy Mandelstam's dispersion-integral representation is presented. Sets are identified that are free from kinematical constraints and that can be computed efficiently in terms of a novel projection algebra. From such a representation one can deduce the analytic structure of the partial-wave amplitudes. The helicity and the conventional angular-momentum partial-wave amplitudes are kinematically constrained at the Kibble conditions. Therefore an application of a dispersion-integral representation is prohibitively cumbersome. We derive covariant partial-wave amplitudes that are free from kinematical constraints at the Kibble conditions. They correspond to specific polynomials in the 4-momenta and Dirac matrices that solve the various Bethe-Salpeter equations in the presence of short-range interactions analytically.
Hyperon AND Hyperon Resonance Properties From Charm Baryon Decays At BaBar
Energy Technology Data Exchange (ETDEWEB)
Ziegler, Veronique; /Iowa U.
2007-07-03
This report describes studies of hyperons and hyperon resonances produced in charm baryon decays at BABAR. Using two-body decays of the {Xi}{sub c}{sup 0} and {Omega}{sub c}{sup 0}, it is shown, for the first time, that the spin of the {omega}{sup -} is 3/2. The {Omega}{sup -} analysis procedures are extended to three-body final states and properties of the {Xi}(1690){sup 0} are extracted from a detailed isobar model analysis of the {Lambda}{sub c}{sup +} {yields} {Lambda}{bar K}{sup 0}K{sup +} Dalitz plot. The mass and width values of the {Xi}(1690){sup 0} are measured with much greater precision than attained previously. The hypothesis that the spin of the {Xi}(1690) resonance is 1/2 yields an excellent description of the data, while spin values 3/2 and 5/2 are disfavored. The {Lambda}a{sub 0}(980){sup +} decay mode of the {Lambda}{sub c}{sup +} is observed for the first time. Similar techniques are then used to study {Xi}(1530){sup 0} production in {Lambda}{sub c}{sup +} decay. The spin of the {Xi}(1530) is established for the first time to be 3/2. The existence of an S-wave amplitude in the {Xi}{sup -}{pi}{sup +} system is shown, and its interference with the {Xi}(1530){sup 0} amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the {Xi}(1530). The {Xi}{sup -}{pi}{sup +} mass distribution in the vicinity of the {Xi}(1690){sup 0} exhibits interesting structure which may be interpreted as indicating that the {Xi}(1690) has negative parity.
Energy Technology Data Exchange (ETDEWEB)
M. Ripani; V.D. Burkert; V. Mokeev; M. Battaglieri; R. De Vita; E. Golovach; M. Taiuti; et al
2003-04-01
The cross section for the reaction ep {yields} e{prime} p{pi}{sup +}{pi}{sup -} was measured in the resonance region for 1.4 < W < 2.1 GeV and 0.5 < Q{sup 2} < 1.5 GeV{sup 2}/c{sup 2} using the CLAS detector at Jefferson Laboratory. The data show resonant structures not visible in previous experiments. The comparison of our data to a phenomenological prediction using available information on N* and {Delta} states shows an evident discrepancy. A better description of the data is obtained either by a sizeable change of the properties of the P{sub 13}(1720) resonance or by introducing a new baryon state, not reported in published analyses.
The $ep \\to e'p\\eta$ reaction at and above the $S_{11}(1535)$ baryon resonance
Thompson, R; Kim, K Y; Müller, J; Adams, G S; Amaryan, M J; Anciant, E; Anghinolfi, M; Asavapibhop, B; Auger, T; Audit, G; Avakian, H; Barrow, S; Battaglieri, M; Beard, K; Bektasoglu, M; Berman, Barry L; Bertozzi, W; Bianchi, N; Biselli, A; Boiarinov, S; Bonner, B E; Briscoe, W J; Brooks, W; Burkert, V D; Calarco, J R; Capitani, G P; Carman, D S; Carnahan, B; Cetina, C; Cole, P L; Coleman, A; Connelly, J; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J; Day, D; Degtyarenko, P V; Demirchyan, R A; Dennis, L C; Deppman, A; De Sanctis, E; De Vita, R; Dhuga, K S; Djalali, C; Dodge, G E; Doughty, D C; Dragovitsch, P; Dugger, M R; Eckhause, M; Efremenko, Yu V; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Farhi, L; Feuerbach, R J; Ficenec, J; Fissum, K; Freyberger, A P; Funsten, H O; Gai, M; Gavrilov, V B; Gilfoyle, G P; Giovanetti, K L; Gilad, S; Girard, P M; Griffioen, K A; Guidal, M; Guillo, M R; Gyurjyan, V; Hancock, D; Hardie, J; Heddle, D; Heisenberg, J H; Hersman, F W; Hicks, K; Hicks, R S; Holtrop, M; Hyde-Wright, C E; Ito, M M; Jenkins, D; Joo, K K; Kane, J; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klusman, M; Kossov, M; Kuhn, S E; Kuang, Y; Laget, J M; Lawrence, D; Leskin, G A; Longhi, A; Loukachine, K; Lucas, M; Magahiz, R; Major, R W; Manak, J J; Marchand, C; Matthews, S K; Maximon, L; McAleer, S; McCarthy, J; McNabb, J W C; Mecking, B A; Mestayer, M D; Meyer, C A; Minehart, R C; Mirazita, M; Miskimen, R; Muccifora, V; Murphy, L; Mutchler, G S; Napolitano, J; Niyazov, R A; Ohandjanyan, M S; O'Brien, J T; Opper, A K; Patois, Y; Perrot-Kunne, F; Peterson, G A; Philips, S; Pivnyuk, N A; Pocanic, D; Pogorelko, O I; Polli, E; Preedom, B M; Price, J W; Qin, L M; Raue, B A; Reolon, A R; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rossi, P; Roudot, F; Rowntree, D; Rubin, P D; Salgado, C W; Sanzone, M; Sapunenko, V; Sarty, A J; Sargsyan, M; Schumacher, R A; Shafi, A; Sharabyan, Yu G; Shaw, J; Shuvalov, S M; Skabelin, A V; Smith, T; Smith, C; Smith, E S; Sober, D I; Spraker, M; Stepanyan, S; Stoler, P; Taiuti, M; Taragin, M F; Taylor, S; Tedeschi, D J; Tung, T Y; Vineyard, M F; Vlasov, A; Weller, H; Weinstein, L B; Welsh, R; Weygand, D P; Whisnant, S; Witkowski, M T; Wolin, E; Yegneswaran, A; Yun, J; Zhou, Z; Zhao, J
2001-01-01
New cross sections for the reaction e p -> ep eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q^2 = 0.25--1.5 GeV^2. This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Expanded W coverage shows sharp structure at W \\~ 1.7 GeV; this is shown to come from interference between S and P waves and can be interpreted in terms of known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.
Observation of an Exotic S = -2, Q = -2 Baryon Resonance in Proton-Proton Collisions at the CERN SPS
Alt, C; Baatar, B; Barna, D; Bartke, Jerzy; Behler, M; Betev, L; Bialkowska, H; Billmeier, A; Blume, C; Boimska, B; Botje, M; Bracinik, J; Bramm, R; Brun, R; Buncic, P; Cerny, V; Christakoglou, P; Chvala, O; Cramer, J G; Csató, P; Darmenov, N; Dimitrov, A; Dinkelaker, P; Eckardt, V; Farantatos, G; Filip, P; Flierl, D; Fodor, Z; Foka, P; Freund, P; Friese, V; Gál, J; Gazdzicki, M; Georgopoulos, G; Gladysz-Dziadus, E; Hegyi, S; Höhne, C; Kadija, K; Karev, A; Kniege, S; Kolesnikov, V I; Kollegger, T; Korus, R; Kowalski, M; Kraus, I; Kreps, M; Van Leeuwen, M; Lévai, Peter; Litov, L; Makariev, M; Malakhov, A I; Markert, C; Mateev, M; Mayes, B W; Melkumov, G L; Meurer, C; Mischke, A; Mitrovski, M; Molnár, J; Mrówczynski, S; Pálla, G; Panagiotou, A D; Panayotov, D; Perl, K; Petridis, A; Pikna, M; Pinsky, L; Pühlhofer, F; Reid, J G; Renfordt, R E; Retyk, W; Roland, C; Roland, G; Rybczynski, M; Rybicki, A; Sandoval, A; Sann, H; Schmitz, N; Seyboth, P; Siklér, F; Sitár, B; Skrzypczak, E; Stefanek, G; Stock, R; Ströbele, H; Susa, T; Szentpétery, I; Sziklai, J; Trainor, T A; Varga, D; Vassiliou, Maria; Veres, G I; Vesztergombi, G; Vranic, D; Wetzler, A; Wlodarczyk, Z; Yoo, I K; Zaranek, J; Zimányi, J
2004-01-01
Results of resonance searches in the Xi- pi-, Xi- pi+, antiXi+ pi- and antiXi+ pi+ invariant mass spectra in proton-proton collisions at sqrt{s}=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi- pi- baryon resonance with mass of 1.862+/-0.002 GeV/c^2 and width below the detector resolution of about 0.018 GeV/c^2. The significance is estimated to be 4.0 sigma. This state is a candidate for the hypothetical exotic Xi_(3/2)^-- baryon with S = -2, I = 3/2 and a quark content of (d s d s ubar). At the same mass a peak is observed in the Xi- pi+ spectrum which is a candidate for the Xi_(3/2)^0 member of this isospin quartet with a quark content of (d s u s dbar). The corresponding antibaryon spectra also show enhancements at the same invariant mass.
Evidence for an exotic S=-2, Q=-2 baryon resonance in proton-proton collisions at the CERN SPS
Alt, C; Baatar, B; Barna, D; Bartke, Jerzy; Betev, L; Bialkowska, H; Billmeier, A; Blume, C; Boimska, B; Botje, M; Bracinik, J; Bramm, R; Brun, R; Buncic, P; Cerny, V; Christakoglou, P; Chvala, O; Cramer, J G; Csató, P; Darmenov, N; Dimitrov, A; Dinkelaker, P; Eckardt, V; Farantatos, G; Filip, P; Flierl, D; Fodor, Z; Foka, P; Freund, P; Friese, V; Gál, J; Gazdzicki, M; Georgopoulos, G; Gladysz-Dziadus, E; Hegyi, S; Höhne, C; Kadija, K; Karev, A; Kniege, S; Kolesnikov, V I; Kollegger, T; Korus, R; Kowalski, M; Kraus, I; Kreps, M; Van Leeuwen, M; Lévai, Peter; Litov, L; Makariev, M; Malakhov, A I; Markert, C; Mateev, M; Mayes, B W; Melkumov, G L; Meurer, C; Mischke, A; Mitrovski, M; Molnár, J; Mrówczynski, S; Palla, G K; Panagiotou, A D; Panayotov, D; Perl, K; Petridis, A; Pikna, M; Pinsky, L; Pühlhofer, F; Reid, J G; Renfordt, R E; Retyk, W; Roland, C; Roland, G; Rybczynski, M; Rybicki, A; Sandoval, A; Sann, H; Schmitz, N; Seyboth, P; Siklér, F; Sitár, B; Skrzypczak, E; Stefanek, G; Stock, R; Ströbele, H; Susa, T; Szentpétery, I; Sziklai, J; Trainor, T A; Varga, D; Vassiliou, Maria; Veres, G I; Vesztergombi, G; Vranic, D; Wetzler, A; Wlodarczyk, Z; Yoo, I K; Zaranek, J; Zimányi, J
2004-01-01
Results of resonance searches in the Xi /sup -/ pi /sup -/, Xi /sup - / pi /sup +/, Xi /sup +/ pi /sup -/, and Xi /sup +/ pi /sup +/ invariant mass spectra in proton-proton collisions at square root s =17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi /sup -/ pi /sup -/ baryon resonance with mass of 1.862+or-0.002 GeV/c/sup 2/ and width below the detector resolution of about 0.018 GeV/c/sup 2/. The significance is estimated to be above 4.2 sigma . This state is a candidate for the hypothetical exotic Xi /sub 3/2//sup --/ baryon with S=-2, I=/sup 3///sub 2/, and a quark content of (dsdsu). At the same mass, a peak is observed in the Xi /sup -/ pi /sup +/ spectrum which is a candidate for the Xi /sub 3/2//sup 0/ member of this isospin quartet with a quark content of (dsusd). The corresponding antibaryon spectra also show enhancements at the same invariant mass. (21 refs).
Evidence for an exotic S= -2, Q= -2 baryon resonance in proton-proton collisions at the CERN SPS.
Alt, C; Anticic, T; Baatar, B; Barna, D; Bartke, J; Betev, L; Białkowska, H; Billmeier, A; Blume, C; Boimska, B; Botje, M; Bracinik, J; Bramm, R; Brun, R; Buncić, P; Cerny, V; Christakoglou, P; Chvala, O; Cramer, J G; Csató, P; Darmenov, N; Dimitrov, A; Dinkelaker, P; Eckardt, V; Farantatos, G; Filip, P; Flierl, D; Fodor, Z; Foka, P; Freund, P; Friese, V; Gál, J; Gaździcki, M; Georgopoulos, G; Gładysz, E; Hegyi, S; Höhne, C; Kadija, K; Karev, A; Kniege, S; Kolesnikov, V I; Kollegger, T; Korus, R; Kowalski, M; Kraus, I; Kreps, M; van Leeuwen, M; Lévai, P; Litov, L; Makariev, M; Malakhov, A I; Markert, C; Mateev, M; Mayes, B W; Melkumov, G L; Meurer, C; Mischke, A; Mitrovski, M; Molnár, J; Mrówczyński, St; Pálla, G; Panagiotou, A D; Panayotov, D; Perl, K; Petridis, A; Pikna, M; Pinsky, L; Pühlhofer, F; Reid, J G; Renfordt, R; Retyk, W; Roland, C; Roland, G; Rybczyński, M; Rybicki, A; Sandoval, A; Sann, H; Schmitz, N; Seyboth, P; Siklér, F; Sitar, B; Skrzypczak, E; Stefanek, G; Stock, R; Ströbele, H; Susa, T; Szentpétery, I; Sziklai, J; Trainor, T A; Varga, D; Vassiliou, M; Veres, G I; Vesztergombi, G; Vranić, D; Wetzler, A; Włodarczyk, Z; Yoo, I K; Zaranek, J; Zimányi, J
2004-01-30
Results of resonance searches in the Xi(-)pi(-), Xi(-)pi(+), Xi;(+)pi(-), and Xi;(+)pi(+) invariant mass spectra in proton-proton collisions at sqrt[s]=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi(-)pi(-) baryon resonance with mass of 1.862+/-0.002 GeV/c(2) and width below the detector resolution of about 0.018 GeV/c(2). The significance is estimated to be above 4.2sigma. This state is a candidate for the hypothetical exotic Xi(--)(3/2) baryon with S=-2, I=3 / 2, and a quark content of (dsdsū). At the same mass, a peak is observed in the Xi(-)pi(+) spectrum which is a candidate for the Xi(0)(3/2) member of this isospin quartet with a quark content of (dsus[-]d). The corresponding antibaryon spectra also show enhancements at the same invariant mass.
Aleev, A; Ardashev, E; Balandin, V; Basiladze, Sergei G; Berezhnev, S; Bogdanova, G A; Boguslavsky, M; Egorov, N; Ejov, V; Ermakov, G; Ermolov, P; Furmanec, N; Golovnia, S; Golubkov, S; Gorkov, A; Gorokhov, S; Gramenitsky, I; Grishin, N; Grishkevich, Ya; Karmanov, D; Kholodenko, A; Kiriakov, A; Kosarev, I; Kouzmine, N; Kozlov, V; Kozlov, Yu; Kokoulina, E; Korotkov, N V; Kramarenko, V; Kubarovsky, A; Kurchaninov, L L; Kuzmin, V; Kuznetsov, E; Lanshikov, G; Larichev, A; Leflat, A; Levitsky, M; Lyutov, S; Maiorov, S; Merkin, M; Minaenko, A A; Mitrofanov, G Ya; Moiseev, A; Murzin, V; Nikitin, V; Nomokonov, V P; Oleinik, A; Orfanitsky, S V; Parakhin, V; Petrov, V; Pilavova, L; Pleskach, A; Popov, V; Riadovikov, V; Rudenko, R; Rufanov, I; Senko, V; Shafranov, M; Shalanda, N A; Sidorov, A; Soldatov, M; Tikhonova, L A; Topuria, T; Tsyupa, Yu; Vasilev, M; Vischnevskaya, A; Volkov, V; Vorobev, A; Voronin, A; Yakimchuk, V; Yukaev, A I; Zakamsky, L; Zapolskii, V N; Zhidkov, N; Zmushko, V V; Zotkin, S A; Zotkin, D S; Zverev, E
2004-01-01
SVD-2 experiment data have been analyzed to search for an exotic baryon state, the $\\Theta^+$-baryon, in a $pK^0_s$ decay mode at $70 GeV/c$ on IHEP accelerator. The reaction $pA \\to pK^0_s+X$ with a limited multiplicity was used in the analysis. The $pK^0_s$ invariant mass spectrum shows a resonant structure with $M=1526\\pm3(stat.)\\pm 3(syst.) MeV/c^2$ and $\\Gamma < 24 MeV/c^2$. The statistical significance of this peak was estimated to be of $5.6 \\sigma$. The mass and width of the resonance is compatible with the recently reported $\\Theta^+$- baryon with positive strangeness which was predicted as an exotic pentaquark ($uudd\\bar{s}$) baryon state. The total cross section for $\\Theta^+$ production in pN-interactions for $X_F\\ge 0$ was estimated to be $(30\\div120) \\mu b$ and no essential deviation from A-dependence for inelastic events $(\\sim A^{0.7})$ was found.
Airapetian, A; Akopov, Z; Amarian, M; Ammosov, V V; Andrus, A; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetisian, A; Avetissian, E; Bailey, P; Baturin, V; Baumgarten, C; Beckmann, M; Belostotskii, S; Bernreuther, S; Bianchi, N; Blok, H P; Böttcher, Helmut B; Borisov, A; Bouwhuis, M; Brack, J; Brüll, A; Bryzgalov, V V; Capitani, G P; Chiang, H C; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; De Leo, R; De Nardo, L; De Sanctis, E; Devitsin, E G; Di Nezza, P; Düren, M; Ehrenfried, M; Elalaoui-Moulay, A; Elbakian, G M; Ellinghaus, F; Elschenbroich, U; Ely, J; Fabbri, R; Fantoni, A; Feshchenko, A; Felawka, L; Fox, B; Franz, J; Frullani, S; Gärber, Y; Gapienko, G; Gapienko, V; Garibaldi, F; Garrow, K; Garutti, E; Gaskell, D; Gavrilov, G E; Karibian, V; Graw, G; Grebenyuk, O; Greeniaus, L G; Hafidi, K; Hartig, M; Hasch, D; Heesbeen, D; Henoch, M; Hertenberger, R; Hesselink, W H A; Hillenbrand, A; Hoek, M; Holler, Y; Hommez, B; Iarygin, G; Ivanilov, A; Izotov, A; Jackson, H E; Jgoun, A; Kaiser, R; Kinney, E; Kiselev, A; Königsmann, K C; Kopytin, M; Korotkov, V A; Kozlov, V; Krauss, B; Krivokhizhin, V G; Lagamba, L; Lapikas, L; Laziev, A; Lenisa, P; Liebing, P; Lindemann, T; Lipka, K; Lorenzon, W; Lü, J; Maiheu, B; Makins, N C R; Marianski, B; Marukyan, H O; Masoli, F; Mexner, V; Meyners, N; Miklukho, O; Miller, C A; Miyachi, Y; Muccifora, V; Nagaitsev, A; Nappi, E; Naryshkin, Yu; Nass, A; Negodaev, M A; Nowak, Wolf-Dieter; Oganessyan, K; Ohsuga, H; Orlandi, G; Pickert, N; Potashov, S Yu; Potterveld, D H; Raithel, M; Reggiani, D; Reimer, P E; Reischl, A; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubacek, L; Ryckbosch, D; Salomatin, Yu I; Sanjiev, I; Savin, I; Scarlett, C; Schäfer, A; Schill, C; Schnell, G; Schüler, K P; Schwind, A; Seele, J; Seidl, R; Seitz, B; Shanidze, R G; Shearer, C; Shibata, T A; Shutov, V B; Simani, M C; Sinram, K; Stancari, M D; Statera, M; Steffens, E; Steijger, J J M; Stewart, J; Stösslein, U; Tait, P; Tanaka, H; Taroian, S P; Tchuiko, B; Terkulov, A R; Tkabladze, A V; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van der Nat, P B; van der Steenhoven, G; Vetterli, Martin C; Vikhrov, V; Vincter, M G; Visser, J; Vogel, C; Vogt, M; Volmer, J; Weiskopf, C; Wendland, J; Wilbert, J; Ybeles-Smit, G V; Yen, S; Zihlmann, B; Zohrabyan, H G; Zupranski, P
2004-01-01
A search for an exotic baryon resonance with $S=-2, Q=-2$ has been performed in quasi-real photoproduction on a deuterium target through the decay channel $\\Xi^- \\pi^- \\to \\Lambda \\pi^- \\pi^- \\to p \\pi^- \\pi^- \\pi^-$. No evidence for a previously reported $\\Xi^{--}(1860)$ resonance is found in the $\\Xi^- \\pi^-$invariant mass spectrum. An upper limit for the photoproduction cross section of 2.1 nb is found at the 90% confidence level. The photoproduction cross section for the $\\Xi^{0}(1530)$ is found to be between 9 and 24 nb.
Evidence for a bottom baryon resonance Lambda_b* in CDF data
Aaltonen, Timo Antero; Amidei, Dante E; Anastassov, Anton Iankov; Annovi, Alberto; Antos, Jaroslav; Apollinari, Giorgio; Appel, Jeffrey A; Arisawa, Tetsuo; Artikov, Akram Muzafarovich; Asaadi, Jonathan A; Ashmanskas, William Joseph; Auerbach, Benjamin; Aurisano, Adam J; Azfar, Farrukh A; Badgett, William Farris; Bae, Taegil; Barbaro-Galtieri, Angela; Barnes, Virgil E; Barnett, Bruce Arnold; Barria, Patrizia; Bartos, Pavol; Bauce, Matteo; Bedeschi, Franco; Behari, Satyajit; Bellettini, Giorgio; Bellinger, James Nugent; Benjamin, Douglas P; Beretvas, Andrew F; Bhatti, Anwar Ahmad; Bland, Karen Renee; Blumenfeld, Barry J; Bocci, Andrea; Bodek, Arie; Bortoletto, Daniela; Boudreau, Joseph Francis; Boveia, Antonio; Brigliadori, Luca; Bromberg, Carl Michael; Brucken, Erik; Budagov, Ioulian A; Budd, Howard Scott; Burkett, Kevin Alan; Busetto, Giovanni; Bussey, Peter John; Butti, Pierfrancesco; Buzatu, Adrian; Calamba, Aristotle; Camarda, Stefano; Campanelli, Mario; Canelli, Florencia; Carls, Benjamin; Carlsmith, Duncan L; Carosi, Roberto; Carrillo Moreno, Salvador; Casal Larana, Bruno; Casarsa, Massimo; Castro, Andrea; Catastini, Pierluigi; Cauz, Diego; Cavaliere, Viviana; Cavalli-Sforza, Matteo; Cerri, Alessandro; Cerrito, Lucio; Chen, Yen-Chu; Chertok, Maxwell Benjamin; Chiarelli, Giorgio; Chlachidze, Gouram; Cho, Kihyeon; Chokheli, Davit; Clark, Allan Geoffrey; Clarke, Christopher Joseph; Convery, Mary Elizabeth; Conway, John Stephen; Corbo, Matteo; Cordelli, Marco; Cox, Charles Alexander; Cox, David Jeremy; Cremonesi, Matteo; Cruz Alonso, Daniel; Cuevas Maestro, Javier; Culbertson, Raymond Lloyd; D'Ascenzo, Nicola; Datta, Mousumi; de Barbaro, Pawel; Demortier, Luc M; Marchese, Luigi Marchese; Deninno, Maria Maddalena; Devoto, Francesco; D'Errico, Maria; Di Canto, Angelo; Di Ruzza, Benedetto; Dittmann, Jay Richard; D'Onofrio, Monica; Donati, Simone; Dorigo, Mirco; Driutti, Anna; Ebina, Koji; Edgar, Ryan Christopher; Elagin, Andrey L; Erbacher, Robin D; Errede, Steven Michael; Esham, Benjamin; Farrington, Sinead Marie; Fernández Ramos, Juan Pablo; Field, Richard D; Flanagan, Gene U; Forrest, Robert David; Franklin, Melissa EB; Freeman, John Christian; Frisch, Henry J; Funakoshi, Yujiro; Galloni, Camilla; Garfinkel, Arthur F; Garosi, Paola; Gerberich, Heather Kay; Gerchtein, Elena A; Giagu, Stefano; Giakoumopoulou, Viktoria Athina; Gibson, Karen Ruth; Ginsburg, Camille Marie; Giokaris, Nikos D; Giromini, Paolo; Giurgiu, Gavril A; Glagolev, Vladimir; Glenzinski, Douglas Andrew; Gold, Michael S; Goldin, Daniel; Golossanov, Alexander; Gomez, Gervasio; Gomez-Ceballos, Guillelmo; Goncharov, Maxim T; González López, Oscar; Gorelov, Igor V; Goshaw, Alfred T; Goulianos, Konstantin A; Gramellini, Elena; Grinstein, Sebastian; Grosso-Pilcher, Carla; Group, Robert Craig; Barreiro Guimaraes da Costa, Joao; Hahn, Stephen R; Han, Ji-Yeon; Happacher, Fabio; Hara, Kazuhiko; Hare, Matthew Frederick; Harr, Robert Francis; Harrington-Taber, Timothy; Hatakeyama, Kenichi; Hays, Christopher Paul; Heinrich, Joel G; Herndon, Matthew Fairbanks; Hocker, James Andrew; Hong, Ziqing; Hopkins, Walter Howard; Hou, Suen Ray; Hughes, Richard Edward; Husemann, Ulrich; Hussein, Mohammad; Huston, Joey Walter; Introzzi, Gianluca; Iori, Maurizio; Ivanov, Andrew Gennadievich; James, Eric B; Jang, Dongwook; Jayatilaka, Bodhitha Anjalike; Jeon, Eun-Ju; Jindariani, Sergo Robert; Jones, Matthew T; Joo, Kyung Kwang; Jun, Soon Yung; Junk, Thomas R; Kambeitz, Manuel; Kamon, Teruki; Karchin, Paul Edmund; Kasmi, Azeddine; Kato, Yukihiro; Ketchum, Wesley Robert; Keung, Justin Kien; Kilminster, Benjamin John; Kim, DongHee; Kim, Hyunsoo; Kim, Jieun; Kim, Min Jeong; Kim, Soo Bong; Kim, Shin-Hong; Kim, Young-Kee; Kim, Young-Jin; Kimura, Naoki; Kirby, Michael H; Knoepfel, Kyle James; Kondo, Kunitaka; Kong, Dae Jung; Konigsberg, Jacobo; Kotwal, Ashutosh Vijay; Kreps, Michal; Kroll, IJoseph; Kruse, Mark Charles; Kuhr, Thomas; Kurata, Masakazu; Laasanen, Alvin Toivo; Lammel, Stephan; Lancaster, Mark; Lannon, Kevin Patrick; Latino, Giuseppe; Lee, Hyun Su; Lee, Jaison; Leo, Sabato; Leone, Sandra; Lewis, Jonathan D; Limosani, Antonio; Lipeles, Elliot David; Lister, Alison; Liu, Hao; Liu, Qiuguang; Liu, Tiehui Ted; Lockwitz, Sarah E; Loginov, Andrey Borisovich; Lucà, Alessandra; Lucchesi, Donatella; Lueck, Jan; Lujan, Paul Joseph; Lukens, Patrick Thomas; Lungu, Gheorghe; Lys, Jeremy E; Lysak, Roman; Madrak, Robyn Leigh; Maestro, Paolo; Malik, Sarah Alam; Manca, Giulia; Manousakis-Katsikakis, Arkadios; Margaroli, Fabrizio; Marino, Christopher Phillip; Martínez-Perez, Mario; Matera, Keith; Mattson, Mark Edward; Mazzacane, Anna; Mazzanti, Paolo; McNulty, Ronan; Mehta, Andrew; Mehtala, Petteri; Mesropian, Christina; Miao, Ting; Mietlicki, David John; Mitra, Ankush; Miyake, Hideki; Moed, Shulamit; Moggi, Niccolo; Moon, Chang-Seong; Moore, Ronald Scott; Morello, Michael Joseph; Mukherjee, Aseet; Muller, Thomas; Murat, Pavel A; Mussini, Manuel; Nachtman, Jane Marie; Nagai, Yoshikazu; Naganoma, Junji; Nakano, Itsuo; Napier, Austin; Nett, Jason Michael; Neu, Christopher Carl; Nigmanov, Turgun S; Nodulman, Lawrence J; Noh, Seoyoung; Norniella Francisco, Olga; Oakes, Louise Beth; Oh, Seog Hwan; Oh, Young-do; Oksuzian, Iuri Artur; Okusawa, Toru; Orava, Risto Olavi; Ortolan, Lorenzo; Pagliarone, Carmine Elvezio; Palencia, Jose Enrique; Palni, Prabhakar; Papadimitriou, Vaia; Parker, William Chesluk; Pauletta, Giovanni; Paulini, Manfred; Paus, Christoph Maria Ernst; Phillips, Thomas J; Piacentino, Giovanni M; Pianori, Elisabetta; Pilot, Justin Robert; Pitts, Kevin T; Plager, Charles; Pondrom, Lee G; Poprocki, Stephen; Potamianos, Karolos Jozef; Prokoshin, Fedor; Pranko, Aliaksandr Pavlovich; Ptohos, Fotios K; Punzi, Giovanni; Ranjan, Niharika; Redondo Fernández, Ignacio; Renton, Peter B; Rescigno, Marco; Rimondi, Franco; Ristori, Luciano; Robson, Aidan; Rodriguez, Tatiana Isabel; Rolli, Simona; Ronzani, Manfredi; Roser, Robert Martin; Rosner, Jonathan L; Ruffini, Fabrizio; Ruiz Jimeno, Alberto; Russ, James S; Rusu, Vadim Liviu; Sakumoto, Willis Kazuo; Sakurai, Yuki; Santi, Lorenzo; Sato, Koji; Saveliev, Valeri; Savoy-Navarro, Aurore; Schlabach, Philip; Schmidt, Eugene E; Schwarz, Thomas A; Scodellaro, Luca; Scuri, Fabrizio; Seidel, Sally C; Seiya, Yoshihiro; Semenov, Alexei; Sforza, Federico; Shalhout, Shalhout Zaki; Shears, Tara G; Shepard, Paul F; Shimojima, Makoto; Shochet, Melvyn J; Tecker-Shreyber, Irina; Simonenko, Alexander V; Sliwa, Krzysztof Jan; Smith, John Rodgers; Snider, Frederick Douglas; Sorin, Maria Veronica; Song, Hao; Stancari, Michelle Dawn; St Denis, Richard Dante; Stentz, Dale James; Strologas, John; Sudo, Yuji; Sukhanov, Alexander I; Suslov, Igor M; Takemasa, Ken-ichi; Takeuchi, Yuji; Tang, Jian; Tecchio, Monica; Teng, Ping-Kun; Thom, Julia; Thomson, Evelyn Jean; Thukral, Vaikunth; Toback, David A; Tokar, Stanislav; Tollefson, Kirsten Anne; Tomura, Tomonobu; Tonelli, Diego; Torre, Stefano; Torretta, Donatella; Totaro, Pierluigi; Trovato, Marco; Ukegawa, Fumihiko; Uozumi, Satoru; Vázquez-Valencia, Elsa Fabiola; Velev, Gueorgui; Vellidis, Konstantinos; Vernieri, Caterina; Vidal Marono, Miguel; Vilar Cortabitarte, Rocio; Vizán Garcia, Jesus Manuel; Vogel, Marcelo; Volpi, Guido; Wagner, Peter; Wallny, Rainer S; Wang, Song-Ming; Waters, David S; Wester, William Carl; Whiteson, Daniel O; Wicklund, Arthur Barry; Wilbur, Scott; Williams, Hugh H; Wilson, Jonathan Samuel; Wilson, Peter James; Winer, Brian L; Wittich, Peter; Wolbers, Stephen A; Wolfe, Homer; Wright, Thomas Roland; Wu, Xin; Wu, Zhenbin; Yamamoto, Kazuhiro; Yamato, Daisuke; Yang, Tingjun; Yang, Un-Ki; Yang, Yu Chul; Yao, Wei-Ming; Yeh, Gong Ping; Yi, Kai; Yoh, John; Yorita, Kohei; Yoshida, Takuo; Yu, Geum Bong; Yu, Intae; Zanetti, Anna Maria; Zeng, Yu; Zhou, Chen; Zucchelli, Stefano
2013-01-01
Using data from proton-antiproton collisions at Ecms=1.96 TeV recorded by the CDF II detector at the Fermilab Tevatron, evidence for the excited resonance state Lambda_b* is presented in its Lambda_b0 pi+ pi- decay, followed by the Lambda_b0 -->Lambda_c+ (-->proton K- pi+) pi- decays. The analysis is based on a data sample corresponding to an integrated luminosity of 9.6/fb collected by an online event selection based on charged-particle tracks displaced from the proton-antiproton interaction point. The significance of the observed signal is 3.5 Gaussian sigmas. The mass of the observed state is found to be 5919.22 +- 0.84 MeV in agreement with similar findings in proton-proton collision experiments.
Evidence for a bottom baryon resonance Λb*0 in CDF data
Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Guimaraes da Costa, J.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Shreyber-Tecker, I.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C., III; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.
2013-10-01
Using data from proton-antiproton collisions at s=1.96TeV recorded by the CDF II detector at the Fermilab Tevatron, evidence for the excited resonance state Λb*0 is presented in its Λb0π-π+ decay followed by the Λb0→Λc+π- and Λc+→pK-π+ decays. The analysis is based on a data sample corresponding to an integrated luminosity of 9.6fb-1 collected by an online event selection based on charged-particle tracks displaced from the proton-antiproton interaction point. The significance of the observed signal is 3.5σ. The mass of the observed state is found to be 5919.22±0.76MeV/c2 in agreement with similar findings in proton-proton collision experiments.
EPECUR setup for the search of narrow baryon resonances in the pion-proton scattering
Andreev, V A; Golubev, V V; Gridnev, A B; Kovalev, A I; Kozlenko, N G; Kozlov, V S; Krivshich, A G; Novinsky, D V; Sadler, M E; Sumachev, V V; Tarakanov, V I; Trautman, V Yu
2013-01-01
EPECUR experimental setup is aimed at the search of narrow resonant states by precision measurement of differential and total reaction cross sections of pion-nucleon interaction with 1 MeV pion energy steps. In five years passed from the idea of the experiment till the start of the data taking in April of 2009, a new apparatus was build from scratch at the universal beam line 322 of ITEP proton synchrotron U-10. The setup is essentially a non-magnetic spectrometer with a liquid hydrogen target based on the large aperture drift chambers with hexagonal structure. The unique properties of the beam line allow individual pion momentum measurement with the accuracy better than 0.1%. The momentum tagging is done with 1 mm pitch proportional chambers located in the first focus of the beam line. The design of numerous subsystems of the setup is based on modern electronic components including microprocessors and FPGA. All the subsystems are tuned and tested both individually and as parts of the whole working setup. The...
A Relativistic Model for the Electromagnetic Structure of Baryons from the 3rd Resonance Region
Ramalho, G
2016-01-01
We present some predictions for the $\\gamma^\\ast N \\to N^\\ast$ transition amplitudes, where $N$ is the nucleon, and $N^\\ast$ is a nucleon excitation from the third resonance region. First we estimate the transition amplitudes associated with the second radial excitation of the nucleon, interpreted as the $N(1710)$ state, using the covariant spectator quark model. After that, we combine some results from the covariant spectator quark model with the framework of the single quark transition model, to make predictions for the $\\gamma^\\ast N \\to N^\\ast$ transition amplitudes, where $N^\\ast$ is a member of the $SU(6)$-multiplet $[70,1^-]$. The results for the $\\gamma^\\ast N \\to N(1520)$ and $\\gamma^\\ast N \\to N(1535)$ transition amplitudes are used as input to the calculation of the amplitudes $A_{1/2}$, $A_{3/2}$, associated with the $\\gamma^\\ast N \\to N(1650)$, $\\gamma^\\ast N \\to N(1700)$, $\\gamma^\\ast N \\to \\Delta(1620)$, and $\\gamma^\\ast N \\to \\Delta(1700)$ transitions. Our estimates are compared with the avail...
Heavy baryonic resonances, multi strange hadrons and equilibration at SIS18 energies
Steinheimer, J; Becattini, F; Stock, R; Bleicher, M
2016-01-01
We study the details and time dependence of particle production in nuclear collisions at a fixed target beam energy of $E_{\\mathrm{lab}}= 1.76$ A GeV with the UrQMD transport model. We find that the previously proposed production mechanism for multi strange hadrons, $\\phi$ and $\\Xi$, are possible due to secondary interactions of incoming nuclei of the projectile and target with already created nuclear resonances, while the Fermi momenta of the nuclei play only a minor role. We also show how the centrality dependence of these particle multiplicities can be used to confirm the proposed mechanism, as it strongly depends on the number of participants in the reaction. Furthermore we investigate the time dependence of particle production in collisions of Ca+Ca at this beam energy, in order to understand the origins of the apparent chemical equilibration of the measured particle yields. We find that indeed the light hadron yields appear to be in equilibrium already from the very early stage of the collision while in...
Page, P R
2003-01-01
We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.
Liu, Keh-Fei
2016-01-01
The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\\pi N \\sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.
Dynamically generated resonances
Oset, E; Sarkar, S; Sun, Bao Xi; Vacas, M J Vicente; González, P; Vijande, J; Jido, D; Sekihara, T; Torres, A Martinez; Khemchandani, K
2009-01-01
In this talk I report on recent work related to the dynamical generation of baryonic resonances, some made up from pseudoscalar meson-baryon, others from vector meson-baryon and a third type from two meson-one baryon systems. We can establish a correspondence with known baryonic resonances, reinforcing conclusions previously drawn and bringing new light on the nature of some baryonic resonances of higher mass.
Anisovich, A V; Sarantsev, A V
2016-01-01
Vertex operators for photo- and electro-production of baryon states with arbitrary spin-parity, $ \\gamma + N\\to B(J^P)$, are constructed. The operators obey gauge invariance and analyticity constraints. Analyticity is realized as a requirement of the generalized Siegert theorem for vertex form factors.
Aleev, A; Balandin, V; Basiladze, Sergei G; Berezhnev, S; Bogdanova, G A; Boguslavsky, M; Bychkov, V; Egorov, N; Ejov, V; Ermakov, G; Ermolov, P; Furmanec, N; Golovkin, V; Golovnia, S; Golubkov, S; Gorkov, A; Gorokhov, S; Gramenitsky, I; Grishin, N; Grishkevich, Y; Karmanov, D; Kholodenko, A; Kiriakov, A; Kouzmine, N; Kozlov, V; Kozlov, Yu; Kokoulina, E; Kramarenko, V; Kubarovsky, A; Kurchaninov, L L; Kuzmin, V; Kuznetsov, E; Lanshikov, G; Larichev, A; Leflat, A; Levitsky, M; Lyutov, S; Merkin, M; Minaenko, A A; Mitrofanov, G Ya; Murzin, V; Nikitin, V; Nomokonov, V P; Orfanitsky, S V; Parakhin, V; Petrov, V; Pilavova, L; Peshekhonov, V D; Pleskach, A; Popov, V; Riadovikov, V; Rudenko, R; Rufanov, I; Senko, V; Shalanda, N A; Sidorov, A; Soldatov, M; Tikhonova, L A; Topuria, T; Tsyupa, Yu; Uzbyakova, A; Vasilev, M; Vischnevskaya, A; Viriasov, K; Volkov, V; Vorobev, A; Voronin, A; Yakimchuk, V; Yukaev, A I; Zakamsky, L; Zapolskii, V N; Zhidkov, N; Zmushko, V V; Zotkin, S A; Zotkin, D S; Zverev, E
2005-01-01
The inclusive reaction $p A \\to pK^0_s + X$ was studied at IHEP accelerator with $70 GeV$ proton beam using SVD-2 detector. Two different samples of $K^0_s$, statistically independent and belonging to different phase space regions were used in the analyses and a narrow baryon resonance with the mass $M=1523\\pm 2(stat.)\\pm 3(syst.) MeV/c^2$ was observed in both samples of the data. The statistical significance was estimated to be of $8.0~\\sigma$ (392 signal over 1990 background events). Using the part of events reconstructed with better accuracy the width of resonance was estimated to be $\\Gamma < 14 MeV/c^2$ at 95% C.L.
Aktas, A; Anthonis, T; Antunovic, B; Aplin, S; Asmone, A; Astvatsatourov, A; Aubert, B; Babaev, A; Backovic, S; Baghdasaryan, A; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baudrand, S; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, N; Bizot, J C; Boenig, M O; Boudry, V; Bracinik, J; Brandt, G; Brisson, V; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Contreras, J G; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; De Boer, Y; Delcourt, B; Del Degan, M; de Roeck, A; De Wolf, E A; Diaconu, C; Dodonov, V; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Eliseev, A; Elsen, E; Essenov, S; Falkewicz, A; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Finke, L; Fleischer, M; Flucke, G; Fomenko, A; Franke, G; Frisson, T; Gabathuler, E; Garutti, E; Gayler, J; Gerlich, C; Ghazaryan, S; Ginzburgskaya, S; Glazov, A; Glushkov, I; Görlich, L; Goettlich, M; Gogitidze, N; Gorbounov, S; Grab, C; Greenshaw, T; Gregori, M; Grell, B R; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Herrera-Corral, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Hreus, T; Hussain, S; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, A W; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Korbel, V; Kostka, P; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Krüger, K; Landon, M P J; Lange, W; Lastoviicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; Liptaj, A; List, B; List, J; Lobodzinska, E; Loktionova, N; López-Fernandez, R; Lubimov, V; Lucaci-Timoce, A I; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marshall, R; Marti, L; Martisikova, M; Martyn, H U; Maxfield, S J; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Milstead, D; Mladenov, D; Mohamed, A; Moreau, F; Morozov, A; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nankov, K; Naroska, Beate; Naumann, T; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Papadopoulou, T D; Pascaud, C; Patel, G D; Peng, H; Pérez, E; Perez-Astudillo, D; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Portheault, B; Povh, B; Prideaux, P; Rahmat, A J; Raicevic, N; Reimer, P; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rurikova, Z; Rusakov, S; Salvaire, F; Sankey, D P C; Sauvan, E; Schatzel, S; Schmidt, S; Schmitt, S; Schmitz, C; Schoeffel, L; Schöning, A; Schultz-Coulon, H C; Sefkow, F; Shaw-West, R N; Shevyakov, I; Shtarkov, L N; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Steder, M; Stella, B; Stiewe, J; Stoilov, A; Straumann, U; Sunar, D; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Traynor, D; Truöl, P; Tsakov, I; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Urban, K; Urban, M; Usik, A; Utkin, D; Valkárová, A; Vallée, C; Van Mechelen, P; Vargas-Trevino, A; Vazdik, Ya A; Veelken, C; Vinokurova, S; Volchinski, V; Wacker, K; Weber, G; Weber, R; Wegener, D; Werner, C; Wessels, M; Wessling, B; Wissing, C; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhelezov, A; Zhokin, A; Zhu, Y C; Zimmermann, J; Zimmermann, T; Zohrabyan, H; Zomer, F
2006-01-01
A search for a narrow baryonic resonance decaying to $K^0_s p$ or $K^0_s \\bar p$ is carried out in deep inelastic ep scattering with the H1 detector at HERA. Such a resonance could be a strange pentaquark \\thplns, evidence for which has been reported by several experiments. The $K^0_s p$ and $K^0_s \\bar p$ invariant mass distributions presented here do not show any significant peak in the mass range from threshold up to 1.7 GeV. Mass dependent upper limits on $\\sigma(ep \\to e \\thplf X)\\times BR(\\thplf \\to K^0 p)$ are obtained at the 95% confidence level.
Baryon spectroscopy and the omega minus
Energy Technology Data Exchange (ETDEWEB)
Samios, N.P.
1994-12-31
In this report, I will mainly discuss baryon resonances with emphasis on the discovery of the {Omega}{sup {minus}}. However, for completeness, I will also present some data on the meson resonances which together with the baryons led to the uncovering of the SU(3) symmetry of particles and ultimately to the concept of quarks.
Bazavov, A; DeTar, C E; Ding, H -T; Gottlieb, Steven; Gupta, Rajan; Hegde, P; Heller, Urs; Karsch, F; Laermann, E; Levkova, L; Mukherjee, Swagato; Petreczky, P; Schmidt, Christian; Soltz, R A; Soeldner, W; Sugar, R; Vranas, Pavlos M
2012-01-01
We calculate the quadratic fluctuations of net baryon number, electric charge and strangeness as well as correlations among these conserved charges in (2+1)-flavor lattice QCD at zero chemical potential. Results in the continuum limit are obtained using calculations with tree level improved gauge and the highly improved staggered quark (HISQ) actions with almost physical light and strange quark masses at three different values of the lattice cut-off. We compare our results with the hadron resonance gas (HRG) model calculations and find agreement with HRG model results only for temperatures T < 150 MeV. We observe significant deviations in the temperature range 160 MeV < T < 170 MeV and qualitative differences in the behavior of the three conserved charge sectors. At $T \\simeq 160 MeV$ quadratic net baryon number fluctuations in QCD agree with HRG model calculations while, the net electric charge fluctuations in QCD are about 10% smaller and net strangeness fluctuations are about 20% larger. These fin...
Predictions for Excited Strange Baryons
Energy Technology Data Exchange (ETDEWEB)
Fernando, Ishara P.; Goity, Jose L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2016-04-01
An assessment is made of predictions for excited hyperon masses which follow from flavor symmetry and consistency with a 1/N c expansion of QCD. Such predictions are based on presently established baryonic resonances. Low lying hyperon resonances which do not seem to fit into the proposed scheme are discussed.
Komarov, V.; Tsirkov, D.; Azaryan, T.; Bagdasarian, Z.; Dymov, S.; Gebel, R.; Gou, B.; Kacharava, A.; Khoukaz, A.; Kulikov, A.; Kurbatov, V.; Lorentz, B.; Macharashvili, G.; Mchedlishvili, D.; Merzliakov, S.; Mikirtytchiants, S.; Ohm, H.; Papenbrock, M.; Rathmann, F.; Serdyuk, V.; Shmakova, V.; Ströher, H.; Trusov, S.; Uzikov, Yu.; Valdau, Yu.
2016-06-01
We report on measurements of the differential cross section d σ /d Ω and the first measurement of the analyzing power Ay in the Δ (1232 ) excitation energy region of the reaction p p →{pp } sπ0 where {pp } s is a S10 proton pair. The experiment has been performed with the ANKE spectrometer at COSY-Jülich. The data reveal a peak in the energy dependence of the forward {pp } s differential cross section, a minimum at zero degrees of its angular distribution, and a large analyzing power. The results present a direct manifestation of two two-baryon resonance-like states with JP=2- and 0- and an invariant mass of 2.2 GeV /c2.
Kang, Xian-Wei; Zou, Bing-Song
2009-01-01
The abundant $\\psi'$ events have been collected at the Beijing Electron Positron Collider-II (BEPCII) which would undoubtedly provide us with a great opportunity to study the more attractive charmonium decays. As has been noticed before, in the process $J/\\psi$ decays to the baryonic final states, $p K^- \\overline{\\Lambda}$, the evident $\\Lambda^*$ and $N^*$ bands have been observed. Similarly, by using the product of $\\chi_{cJ}$ from $\\psi'$ radiative decay, we may confirm it or find some extra new resonances. Here, we provide explicit partial wave analysis formulae for the most interesting channel $\\psi'\\to\\gamma\\chi_{c0}\\to \\gamma p K^- \\overline{\\Lambda}$.
Hadronic molecules in the heavy baryon spectrum
Entem, D. R.; Ortega, P. G.; Fernández, F.
2016-01-01
We study possible baryon molecules in the non-strange heavy baryon spectrum. We include configurations with a heavy-meson and a light baryon. We find several structures, in particular we can understand the Λc(2940) as a D*N molecule with JP = 3/2- quantum numbers. We also find D(*)Δ candidates for the recently discovered Xc(3250) resonance.
Aleev, A; Balandin, V; Basiladze, S; Berezhnev, S; Bogdanova, G; Boguslavsky, I; Bychkov, V; Ejov, V; Ermakov, G; Ermolov, P; Furmanec, N; Golovkin, V; Golovnia, S; Gorokhov, S; Gramenitsky, I; Grishin, N; Grishkevich, Ya; Karmanov, D; Kholodenko, A; Kiriakov, A; Kouzmine, N; Kozlov, V; Kokoulina, E; Kramarenko, V; Kubarovsky, A; Kudryashov, I; Kuzmin, V; Kuznetsov, E; Lanshikov, G; Larichev, A; Leflat, A; Levitsky, M; Lyutov, S; Merkin, M; Minaenko, A; Mitrofanov, G; Nikitin, V; Orfanitsky, S; Parakhin, V; Petrov, V; Peshekhonov, V; Pleskach, A; Popov, V; Riadovikov, V; Ronjin, V; Rufanov, I; Savrina, D; Senko, V; Shalanda, N; Soldatov, M; Tikhonova, L; Topuria, T; Tsyupa, Yu; Uzbyakova, A; Vasilev, M; Vishnevskaya, A; Viriasov, K; Volkov, V; Vorobiev, A; Voronin, A; Yakimchuk, V; Yukaev, A; Zakamsky, L; Zapolsky, V; Zhidkov, N; Zotkin, D; Zotkin, S; Zverev, E
2008-01-01
The inclusive reaction $p A \\to pK^0_s + X$ was studied at IHEP accelerator with $70 GeV/c$ proton beam using SVD-2 detector. Two different samples of $K^0_s$, statistically independent and belonging to different phase space regions, were used in the analyses and a narrow baryon resonance with the mass $M=1523\\pm 2(stat.)\\pm 3(syst.) MeV/c^2$ was observed in both samples of the data. The combined statistical significance was estimated to be of 8.0 (392 signal over 1990 background events). Using the part of events reconstructed with better accuracy the width of resonance was constrained to $\\Gamma \\approx 0.1$}, that qualitatively agrees to a Regge-based model predictions. A new cross section estimate of $\\sigma \\cdot BR(\\Theta^+ \\to pK^0) = 4.9 \\pm 1.0(stat.) \\pm 1.5(syst.) \\mu b/nucleon$ for $x_F > 0$ was obtained.
Exactly solvable models of baryon structure
Bijker, R
1998-01-01
We present a qualitative analysis of the gross features of baryon spectroscopy (masses and form factors) in terms of various exactly solvable models. It is shown that a collective model, in which baryon resonances are interpreted as rotations and vibrations of an oblate symmetric top, provides a good starting point for a more detailed quantitative study.
Exactly solvable models of baryon structure
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico. Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University. Jerusalem 91904, Israel (Israel)
1998-12-31
We present a qualitative analysis of the gross features of baryon spectroscopy (masses and form factors) in terms of various exactly solvable models. It is shown that a collective model, in which baryon resonances are interpreted as rotations and vibrations of an oblate symmetric top, provides a good starting point for a more detailed quantitative study. (Author)
Energy Technology Data Exchange (ETDEWEB)
Mukhopadhyay, N.C.
1986-01-01
The status of the theory of the low-energy approach to hadron structure is reviewed briefly by surveying a few relevant models. A few examples of tests needed to sort out the predictions of different models pertaining to the quark-gluon structure of hadrons are discussed, and given the resulting physics objectives, a few experimental options for excited baryon research at CFBAF are suggested. (LEW)
Energy Technology Data Exchange (ETDEWEB)
Siebenson, Johannes Stephan
2013-04-18
The present work investigates the vacuum properties of the hyperon resonances {Sigma}(1385){sup +} and {Lambda}(1405). For this purpose, p+p reactions at 3.5 GeV kinetic beam energy were analyzed. By using simulations and a special background method, the Breit-Wigner mass and width of the {Sigma}(1385){sup +} could be determined. Furthermore, its production dynamics were studied in different angular distributions. In this context indications were found that the {Sigma}(1385){sup +} partially stems from the decay of a heavy {Delta}-resonance. The investigation of the {Lambda}(1405) was based on similar analysis methods. After acceptance and efficiency corrections, the spectral shape of the {Lambda}(1405) could be extracted. Here a mass shift of this particle to masses below 1400 MeV/c{sup 2} was found. This might reveal important information about the two pole structure of the {Lambda}(1405) and its influence on the low energy anti KN interaction.
Gudnason, Sven Bjarke
2014-01-01
We study a Skyrme-type model with a potential term motivated by Bose-Einstein condensates (BECs), which we call the BEC Skyrme model. We consider two flavors of the model, the first is the Skyrme model and the second has a sixth-order derivative term instead of the Skyrme term; both with the added BEC-motivated potential. The model contains toroidally shaped Skyrmions and they are characterized by two integers P and Q, representing the winding numbers of two complex scalar fields along the toroidal and poloidal cycles of the torus, respectively. The baryon number is B=PQ. We find stable Skyrmion solutions for P=1,2,3,4,5 with Q=1, while for P=6 and Q=1 it is only metastable. We further find that configurations with higher Q>1 are all unstable and split into Q configurations with Q=1.
Baryonic resonances close to the Kbar-N threshold: the case of Lambda(1405) in pp collisions
Agakishiev, G; Belver, D; Belyaev, A V; Berger-Chen, J C; Blanco, A; Böhmer, M; Boyard, J L; Cabanelas, P; Chernenko, S; Dybczak, A; Epple, E; Fabbietti, L; Finocchiaro, P; Fonte, P; Friese, J; Fröhlich, I; Galatyuk, T; Garzón, J A; Gernhäuser, R; Göbel, K; Golubeva, M; González-Díaz, D; Guber, F; Gumberidze, M; Heinz, T; Hennino, T; Holzmann, R; Ierusalimov, A; Iori, I; Ivashkin, A; Jurkovic, M; Kämpfer, B; Karavicheva, T; Koenig, I; Koenig, W; Kolb, B W; Kornakov, G; Kotte, R; Krása, A; Krizek, F; Krücken, R; Kuc, H; Kühn, W; Kugler, A; Kurepin, A; Ladygin, V; Lalik, R; Lang, S; Lapidus, K; Lebedev, A; Liu, T; Lopes, L; Lorenz, M; Maier, L; Mangiarotti, A; Markert, J; Metag, V; Michalska, B; Michel, J; Müntz, C; Naumann, L; Pachmayer, Y C; Palka, M; Parpottas, Y; Pechenov, V; Pechenova, O; Pietraszko, J; Przygoda, W; Ramstein, B; Reshetin, A; Rustamov, A; Sadovsky, A; Salabura, P; Schmah, A; Schwab, E; Siebenson, J; Spataro, S; Spruck, B; Ströbele, H; Stroth, J; Sturm, C; Tarantola, A; Teilab, K; Tlusty, P; Traxler, M; Trebacz, R; Tsertos, H; Vasiliev, T; Wagner, V; Weber, M; Wendisch, C; Wüstenfel, J; Yurevich, S; Zanevsky, Y V
2012-01-01
We present an analysis of the Lambda(1405) resonance produced in the reaction p+p->Sigma^{pm}+pi^{mp}+K+p at 3.5 GeV kinetic beam energy measured with HADES at GSI. The two charged decay channels Lambda(1405) -> Sigma^{\\pm}+pi^{\\mp} have been reconstructed for the first time in p+p collisions. The efficiency and acceptance-corrected spectral shapes show a peak position clearly below 1400 MeV/c^2. We find a total production cross section of sigma_{Lambda(1405)}=9.2 +- 0.9 +- 0.7 +3.3-1.0 mub. The analysis of its polar angle distribution suggests that the Lambda(1405) is produced isotropically in the p-p center of mass system.
Baryonic resonances close to the Kbar-N threshold: the case of Sigma(1385)^+ in pp collisions
Agakishiev, G; Belver, D; Belyaev, A V; Blanco, A; Boehmer, M; Boyard, J L; Cabanelas, P; Castro, E; Chen, J C; Chernenko, S; Christ, T; Destefanis, M; Dohrmann, F; Dybczak, A; Epple, E; Eberl, T; Fabbietti, L; Fateev, O V; Finocchiaro, P; Fonte, P; Friese, J; Froehlich, I; Galatyuk, T; Garzon, J A; Gernhaeuser, R; Gilardi, C; Golubeva, M; Gonzalez-Diaz, D; Guber, F; Gumberidze, M; Heinz, T; Hennino, T; Holzmann, R; Iori, I; Ivashkin, A; Jurkovic, M; Kaempfer, B; Kanaki, K; Karavicheva, T; Koenig, I; Koenig, W; Kolb, B W; Kotte, R; Krasa, A; Krizek, F; Kruecken, R; Kuc, H; Kuehn, W; Kugler, A; Kurepin, A; Lalik, R; Lang, S; Lange, J S; Lapidus, K; Liu, T; Lopes, L; Lorenz, M; Maier, L; Mangiarotti, A; Markert, J; Metag, V; Michalska, B; Michel, J; Moriniere, E; Mousa, J; Muentz, C; Naumann, L; Otwinowski, J; Pachmayer, Y C; Palka, M; Parpottas, Y; Pechenov, V; Pechenova, O; Pietraszko, J; Przygoda, W; Ramstein, B; Reshetin, A; Rustamov, A; Sadovsky, A; Salabura, P; Schmah, A; Schwab, E; Siebenson, J; Sobolev, Yu G; Spataro, S; Spruck, B; Stroebele, H; Stroth, J; Sturm, C; Tarantola, A; Teilab, K; Tlusty, P; Traxler, M; Trebacz, R; Tsertos, H; Wagner, V; Weber, M; Wendisch, C; Wuestenfeld, J; Yurevich, S; Zanevsky, Y V
2011-01-01
We present results of an exclusive measurement of the first excited state of the Sigma hyperon, Sigma(1385)^+, produced in p+p -> Sigma^+ + K^+ + n at 3.5 GeV beam energy. The extracted data allow to study in detail the invariant mass distribution of the Sigma(1385)^+. The mass distribution is well described by a relativistic Breit-Wigner function with a maximum at m_0 = 1383.2 +- 0.9 MeV/c^2 and a width of 40.2 +- 2.1 MeV/c^2. The exclusive production cross-section comes out to be 22.27 +- 0.89 +- 1.56 +3.07 -2.10 mu b. Angular distributions of the Sigma(1385)^+ in different reference frames are found to be compatible with the hypothesis that 33 % of Sigma(1385)^+ result from the decay of an intermediate Delta^{++} resonance.
Energy Technology Data Exchange (ETDEWEB)
Doroshkevich, E.; Bashkanov, M.; Brodowski, W.; Bilger, R.; Clement, H.; Meier, R. [Physikalisches Institut der Universitaet Tuebingen, Morgenstelle 14, D-72076, Tuebingen (Germany); Calen, H.; Ekstroem, C.; Kupsc, A. [Svedberg Laboratory, S-751 21, Uppsala (Sweden); Fransson, K.; Haeggstroem, S.; Hoeistad, B.; Johanson, J.; Johansson, A.; Johansson, T.; Kullander, S.; Marciniewski, P. [Department of Radiation Sciences, Uppsala University (Sweden); Greiff, J. [I. Institut fuer Experimentalphysik der Universitaet Hamburg, D-22761, Hamburg (Germany); Kilian, K. [IKP - Forschungszentrum Juelich GmbH, D-52425, Juelich (Germany); Morosov, B. [Joint Institute for Nuclear Research Dubna, 101000, Moscow (Russian Federation); Oelert, W.; Paetzold, J.; Ruber, R.J.M.Y.; Scobel, W.; Stepaniak, J.; Sukhanov, A.; Turowiecki, A.; Wagner, G.J.; Wilhelmi, Z.; Zabierowski, J.; Zlomanczuk, J.
2003-11-01
Exclusive measurements of the two-pion production channel pp{yields}pp{pi} + {pi}{sup -} have been carried out near threshold at CELSIUS with the PROMICE/WASA detector. They reveal pp{yields}pp{sup *}(1440){yields}pp{sigma}{yields}pp({pi}{sup +}{pi}{sup -}){sub I=l=0} as the dominant process at these energies, however, the data exhibit also significant contributions from p{sup *}(1440){yields}{delta}{pi}{yields}p({pi}{sup +}{pi}{sup -}){sub I=l=0}. From the observed interference of these Roper decay routes their relative branching ratio is derived. The status on the search for NN-decoupled NN{pi}-resonances is reviewed with regard to recent experimental searches in the pionic double charge exchange in nuclei, the two-pion production in nucleon-nucleon collisions, the photo pion-production on the deuteron and the electro pion-production in nuclei. (orig.)
The CMU Baryon Amplitude Analysis Program
Bellis, Matt
2007-05-01
The PWA group at Carnegie Mellon University has developed a comprehensive approach and analysis package for the purpose of extracting the amplitudes for photoproduced baryon resonances. The end goal is to identify any missing resonances that are predicted by the constituent quark model, but not definitively observed in experiments. The data comes from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab.
Algebraic model of baryon structure
Bijker, R
2000-01-01
We discuss properties of baryon resonances belonging to the Nucleon, Delta, Sigma, Lambda, Xi and Omega families in a collective string-like model for the nucleon, in which the radial excitations are interpreted as rotations and vibrations of the string configuration. We find good overall agreement with the available data. The main discrepancies are found for low lying S-wave states, in particular N(1535), N(1650), Sigma(1750), Lambda*(1405), Lambda(1670) and Lambda(1800).
Fukushima, Kenji
2014-01-01
We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.
Ogilvy, Stephen
2015-01-01
The vast amount of $c\\overline{c}$ production that can be recorded by the LHCb detector makes it an ideal environment to study the hadronic production of charmed baryons, along with the properties of their decays. We briefly describe the LHCb experiment and the triggering mechanisms it uses for recording charm production. Previous charmed baryon results from LHCb are detailed, with a description of the future plans for the charmed baryon programme.
Naik, Paras
2016-01-01
The LHCb detector is an excellent instrument for studying the production and decay of charmed baryons in $pp$ collisions, due to efficient triggering mechanisms that capture the copious production of $c\\overline{c}$ at the Large Hadron Collider. The LHCb experiment and its charmed baryon results from LHCb are detailed, with a description of our future plans.
Kubis, B; Meißner, Ulf G; Mei{\\ss}ner, Ulf-G.
1999-01-01
We calculate the form factors of the baryon octet in the framework of heavy baryon chiral perturbation theory. The calculated charge radius of the show that kaon loop effects can play a significant role in the neutron electric form factor. Furthermore. we derive generalized Caldi-Pagels relations between various charge radii which are free of chiral loop effects.
Diquark correlations in baryons: the Interacting Quark Diquark Model
Santopinto, E
2015-01-01
A review of the underlying ideas of the Interacting Quark Diquark Model (IQDM) that asses the baryon spectroscopy in terms of quark diquark degrees of freedom is given, together with a discussion of the missing resonances problem. Some ideas about its generalization the heavy baryon spectroscopy is given.s of freedom is given, together with a discussion of the missing resonances problem. Some ideas about its generalization the heavy baryon spectroscopy is given.The results are compared to the existing experimental data.
An algebraic model of baryon spectroscopy
Bijker, R
1999-01-01
We discuss recent calculations of the mass spectrum, electromagnetic and strong couplings of baryon resonances. The calculations are done in a collective constituent model for the nucleon, in which the resonances are interpreted as rotations and vibrations of a symmetric top with a prescribed distribution of the charge and magnetization. We analyze recent data on eta-photo- and eta-electroproduction, and the tensor analyzing power in deuteron scattering.
Disentanglement of Electromagnetic Baryon Properties
Sadasivan, Daniel; Doring, Michael
2017-01-01
Through recent advances in experimental techniques, the precise extraction of the spectrum of baryonic resonances and their properties becomes possible. Helicity couplings at the resonance pole are fundamental parameters describing the electromagnetic properties of resonances and enabling the comparison of theoretical models with data. We have extracted them from experiments carried out at Jefferson Lab and other facilities using a multipole analysis within the Julich-Bonn framework. Special attention has been paid to the uncertainties and correlations of helicity couplings. Using the world data on the reaction γp -> ηp , we have calculated, for the first time, the covariance matrix. Our results are useful in several ways. They quantify uncertainties but also correlations of helicity couplings. Second, they can tell us quantitatively how useful a given polarization measurement is. Third, they can tell us how the measurement of a new observable would constrain and disentangle the resonance properties which could be helpful in the design of new experiments. Finally, on the subject of the missing resonance problem, model selection techniques and statistical tests allow us to quantify the significance of whether a resonance exists. Supported by NSF CAREER Grant No. PHY-1452055, NSF PIF Grant No. 1415459, by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177, and by Research Center Julich through the HPC grant jikp07.
Charmed baryons on the lattice
Padmanath, M
2015-01-01
We discuss the significance of charm baryon spectroscopy in hadron physics and review the recent developments of the spectra of charmed baryons in lattice calculations. Special emphasis is given on the recent studies of highly excited charm baryon states. Recent precision lattice measurements of the low lying charm and bottom baryons are also reviewed.
Indian Academy of Sciences (India)
Torsten Leddig
2012-11-01
From inclusive measurements, it is known that about 7% of all mesons decay into final states with baryons. In these decays, some striking features become visible compared to mesonic decays. The largest branching fractions come with quite moderate multiplicities of 3–4 hadrons. We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.
Page, P R
2000-01-01
We discuss whether a low-lying hybrid baryon should be defined as a three quark - gluon bound state or as three quarks moving on an excited adiabatic potential. We show that the latter definition becomes exact, not only for very heavy quarks, but also for specific dynamics. We review the literature on the signatures of hybrid baryons, with specific reference to strong hadronic decays, electromagnetic couplings, diffractive production and production in psi decay.
Baryon formation and dissociation in dense hadronic and quark matter
Energy Technology Data Exchange (ETDEWEB)
Wang Jincheng [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Anhui 230026 (China); Institute for Theoretical Physics, Johann Wolfgang Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Wang Qun, E-mail: qunwang@ustc.edu.cn [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Anhui 230026 (China); Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences, Beijing 100049 (China); Rischke, Dirk H. [Institute for Theoretical Physics, Johann Wolfgang Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany)
2011-10-19
We study the formation of baryons as composed of quarks and diquarks in hot and dense hadronic matter in a Nambu-Jona-Lasinio (NJL)-type model. We first solve the Dyson-Schwinger equation for the diquark propagator and then use this to solve the Dyson-Schwinger equation for the baryon propagator. We find that stable baryon resonances exist only in the phase of broken chiral symmetry. In the chirally symmetric phase, we do not find a pole in the baryon propagator. In the color-superconducting phase, there is a pole, but it has a large decay width. The diquark does not need to be stable in order to form a stable baryon, a feature typical for so-called Borromean states. Varying the strength of the diquark coupling constant, we also find similarities to the properties of an Efimov state.
Meson-Baryon Interactions in Unitarized Chiral Perturbation Theory
García-Recio, C; Ruiz-Arriola, E; Vacas, M J V
2003-01-01
Meson-Baryon Interactions can be successfully described using both Chiral Symmetry and Unitarity. The $s-$wave meson-baryon scattering amplitude is analyzed in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry in the potential. Two body coupled channel unitarity is exactly preserved. The needed two particle irreducible matrix amplitude is taken from lowest order Chiral Perturbation Theory in a relativistic formalism. Off-shell behavior is parameterized in terms of low energy constants. The relation to the heavy baryon limit is discussed. The position of the complex poles in the second Riemann sheet of the scattering amplitude determine masses and widths baryonic resonances of the N(1535), N(1670), $\\Lambda (1405)$ and $\\Lambda(1670)$ resonances which compare well with accepted numbers.
Dynamically generated open charmed baryons beyond the zero range approximation
Jimenez-Tejero, C E; Vidaña, I
2009-01-01
The interaction of the low lying pseudo-scalar mesons with the ground state baryons in the charm sector is studied within a coupled channel approach using a t-channel vector-exchange driving force. The amplitudes describing the scattering of the pseudo-scalar mesons off the ground-state baryons are obtained by solving the Lippmann--Schwinger equation. We analyze in detail the effects of going beyond the $t=0$ approximation. Our model predicts the dynamical generation of several open charmed baryon resonances in different isospin and strangeness channels, some of which can be clearly identified with recently observed states.
Baryon spectroscopy with polarization observables from CLAS
Energy Technology Data Exchange (ETDEWEB)
Strauch, Steffen [Univ. of South Carolina, Columbia, SC (United States)
2016-08-01
Meson photoproduction is an important tool in the study of baryon resonances. The spectrum of broad and overlapping nucleon excitations can be greatly clarified by use of polarization observables. The N* program at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) includes experimental studies with linearly and circularly polarized tagged photon beams, longitudinally and transversely polarized nucleon targets, and recoil polarizations. An overview of these experimental studies and recent results will be given.
Screened potential and the baryon spectrum
Vijande, J; Garcilazo, H; Valcarce, A
2003-01-01
We show that in a quark model scheme the use of a screened potential, suggested by lattice QCD, instead of an infinitely rising one with the interquark distance, provides a more adequate description of the high-energy baryon spectrum. In particular an almost perfect parallelism between the predicted and observed number of states comes out throwing new light about the so-called missing resonance problem.
Charmed Bottom Baryon Spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Brown, Zachary S; Detmold, William; Meinel, Stefan; Orginos, Kostas
2014-11-01
The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.
Baryonic Spectroscopy at BESIII
Liu, Fang
Based on 106 million Ψ(3686) events collected with BESIII detector at BEPCII, some results on excited baryons from the partial wave analysis are presented. In the decay of ψ(3686) to pbar{p}π 0, two new baryonic excited states, Jpc = 1/2 + N(2300) and Jpc = 5/2 - N(2570) are significant, and additional 5 well known N* excited states are observed. In ψ(3686) to pbar{p}η , an excited-nucleon state N(1535) is dominant. In ψ(3686) to K - Λ bar{Ξ} + + c.c., two hyperons Ξ(1690) and Ξ(1820) are observed. In ψ(3686) to Λ bar{Σ }π + c.c., some excited strange baryons bar{Λ }* and Σ* are measured on the Σ+π- and Λπ- mass spectra.
(Hybrid) Baryons Symmetries and Masses
Page, P R
1999-01-01
We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and construct the flavour, spin and J^P of hybrid baryons from the symmetries of the system. The lowest mass hybrid baryon is estimated at approximately 2 GeV.
Problems in baryon spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Capstick, S. [Florida State Univ., Tallahassee, FL (United States)
1994-04-01
Current issues and problems in the physics of ground- and excited-state baryons are considered, and are classified into those which should be resolved by CEBAF in its present form, and those which may require CEBAF to undergo an energy upgrade to 8 GeV or more. Recent theoretical developments designed to address these problems are outlined.
Babu, K S; Al-Binni, U; Banerjee, S; Baxter, D V; Berezhiani, Z; Bergevin, M; Bhattacharya, S; Brice, S; Brock, R; Burgess, T W; Castellanos, L; Chattopadhyay, S; Chen, M-C; Church, E; Coppola, C E; Cowen, D F; Cowsik, R; Crabtree, J A; Davoudiasl, H; Dermisek, R; Dolgov, A; Dutta, B; Dvali, G; Ferguson, P; Perez, P Fileviez; Gabriel, T; Gal, A; Gallmeier, F; Ganezer, K S; Gogoladze, I; Golubeva, E S; Graves, V B; Greene, G; Handler, T; Hartfiel, B; Hawari, A; Heilbronn, L; Hill, J; Jaffe, D; Johnson, C; Jung, C K; Kamyshkov, Y; Kerbikov, B; Kopeliovich, B Z; Kopeliovich, V B; Korsch, W; Lachenmaier, T; Langacker, P; Liu, C-Y; Marciano, W J; Mocko, M; Mohapatra, R N; Mokhov, N; Muhrer, G; Mumm, P; Nath, P; Obayashi, Y; Okun, L; Pati, J C; Pattie, R W; Phillips, D G; Quigg, C; Raaf, J L; Raby, S; Ramberg, E; Ray, A; Roy, A; Ruggles, A; Sarkar, U; Saunders, A; Serebrov, A; Shafi, Q; Shimizu, H; Shiozawa, M; Shrock, R; Sikdar, A K; Snow, W M; Soha, A; Spanier, S; Stavenga, G C; Striganov, S; Svoboda, R; Tang, Z; Tavartkiladze, Z; Townsend, L; Tulin, S; Vainshtein, A; Van Kooten, R; Wagner, C E M; Wang, Z; Wehring, B; Wilson, R J; Wise, M; Yokoyama, M; Young, A R
2013-01-01
This report, prepared for the Community Planning Study - Snowmass 2013 - summarizes the theoretical motivations and the experimental efforts to search for baryon number violation, focussing on nucleon decay and neutron-antineutron oscillations. Present and future nucleon decay search experiments using large underground detectors, as well as planned neutron-antineutron oscillation search experiments with free neutron beams are highlighted.
Spontaneous Baryogenesis without Baryon Isocurvature
De Simone, Andrea
2016-01-01
We propose a new class of spontaneous baryogenesis models that does not produce baryon isocurvature perturbations. The baryon chemical potential in these models is independent of the field value of the baryon-generating scalar, hence the scalar field fluctuations are blocked from propagating into the baryon isocurvature. We demonstrate this mechanism in simple examples where spontaneous baryogenesis is driven by a non-canonical scalar field. The suppression of the baryon isocurvature allows spontaneous baryogenesis to be compatible even with high-scale inflation.
Baryon transition form factors at the pole
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the GM, GE, and GC form factors for the Δ (1232 ) resonance excitation at the Breit-Wigner resonance and pole positions up to Q2=5 GeV2 . We also explore the E /M and S /M ratios as functions of Q2. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Baryon transition form factors at the pole
Tiator, L; Workman, R L; Hadžimehmedović, M; Osmanović, H; Omerović, R; Stahov, J; Švarc, A
2016-01-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Baryon transition form factors at the pole
Energy Technology Data Exchange (ETDEWEB)
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Effective Degrees of Freedom in Baryon Spectroscopy
Santopinto, E.; Ferretti, J.
2016-10-01
Three quark and quark-diquark models are characterized by several missing resonances, even if in the latter case the state space is a reduced one. Moreover, even quark-diquark models show some differences in their predictions for missing states. After several years of discussion, we still do not know whether baryons can be completely described in terms of three quark models or if diquark correlations have to be taken into account; another possibility, suggested in Santopinto (Phys Rev C 72:022201, 2005), Ferretti et al. (Phys Rev C 83:065204, 2011) and Galatà and Santopinto (Phys Rev C 86:045202, 2012), is that the previous pictures (three-quark and quark-diquark) represent the dominant descriptions of baryons at different energy scales. New experiments may be planned at Jlab (JLab12), Bes, Belle and LHCb in order to answer this fundamental open question.
Spectrum and Structure of Excited Baryons with CLAS
Burkert, Volker D.
2017-01-01
In this contribution I discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels γp → K+Λ and γp → K+Σ0. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as γp → pω and γp → ϕp are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up significant parts of the excitation strength at large distances. Finally, I give an outlook of baryon resonance physics at the 12 GeV CEBAF electron accelerator. Talk presented at the CRC-16 Symposium, Bonn University, June 6-9, 2016.
Spectrum and Structure of Excited Baryons with CLAS*
Directory of Open Access Journals (Sweden)
Burkert Volker D.
2017-01-01
Full Text Available In this contribution I discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels γp → K+Λ and γp → K+Σ0. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as γp → pω and γp → ϕp are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up significant parts of the excitation strength at large distances. Finally, I give an outlook of baryon resonance physics at the 12 GeV CEBAF electron accelerator.
Leading-order decuplet contributions to the baryon magnetic moments in chiral perturbation theory
Energy Technology Data Exchange (ETDEWEB)
Geng, L.S. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, 46071-Valencia (Spain); Camalich, J. Martin [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, 46071-Valencia (Spain)], E-mail: camalich@ific.uv.es; Vacas, M.J. Vicente [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, 46071-Valencia (Spain)
2009-06-01
We extend an earlier study of the baryon magnetic moments in chiral perturbation theory by the explicit inclusion of the spin-3/2 decuplet resonances. We find that the corrections induced by these heavier degrees of freedom are relatively small in a covariant framework where unphysical spin-1/2 modes are removed. Consequently, implementing the leading SU(3)-breaking corrections given by both the baryon and decuplet contributions, we obtain a description of the baryon-octet magnetic moments that is better than the Coleman-Glashow relations. Finally, we discuss the uncertainties and compare between heavy baryon and covariant approaches.
Properties of the ground-state baryons in chiral perturbation theory
Energy Technology Data Exchange (ETDEWEB)
Martin Camalich, J., E-mail: camalich@ific.uv.e [Departamento de Fisica Teorica and IFIC, Universidad de Valencia-CSIC (Spain); Geng, L.S., E-mail: lisheng.geng@ph.tum.d [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Physik Department, Technische Universitaet Muenchen, D-85747 Garching (Germany); Vicente Vacas, J.M., E-mail: vicente@ific.uv.e [Departamento de Fisica Teorica and IFIC, Universidad de Valencia-CSIC (Spain)
2010-10-15
We review recent progress in the understanding of low-energy baryon structure by means of chiral perturbation theory. In particular, we discuss the application of this formalism to the description of various properties such as the baryon-octet magnetic moments, the electromagnetic structure of decuplet resonances and the hyperon vector coupling f{sub 1}(0). Moreover, we present the results on the chiral extrapolation of recent lattice QCD results on the lowest-lying baryon masses and we predict the corresponding baryonic sigma-terms.
Leading-order decuplet contributions to the baryon magnetic moments in Chiral Perturbation Theory
Geng, L S; Vacas, M J Vicente
2009-01-01
We extend an earlier study of the baryon magnetic moments in chiral perturbation theory by the explicit inclusion of the spin-3/2 decuplet resonances. We find that the corrections induced by these heavier degrees of freedom are relatively small in a covariant framework where unphysical spin-1/2 modes are removed. Consequently, implementing the leading SU(3)-breaking corrections given by both the baryon and decuplet contributions, we obtain a description of the baryon-octet magnetic moments that is better than the Coleman-Glashow relations. Finally, we discuss the uncertainties and compare between heavy baryon and covariant approaches.
Properties of the ground-state baryons in chiral perturbation theory
Martin-Camalich, J; Vacas, M J Vicente
2010-01-01
We review recent progress in the understanding of low-energy baryon structure by means of chiral perturbation theory. In particular, we discuss the application of this formalism to the description of various properties such as the baryon-octet magnetic moments, the electromagnetic structure of decuplet resonances and the hyperon vector coupling $f_1(0)$. Moreover, we present the results on the chiral extrapolation of recent lattice QCD results on the lowest-lying baryon masses and we predict the corresponding baryonic sigma-terms.
Soberman, R K; Soberman, Robert K.; Dubin, Maurice
2001-01-01
A comet-like, but magnitudes smaller, extremely low albedo interstellar meteoroid population of fragile aggregates with solar type composition, measured in space and terrestrially, is most probably the universal dark matter. Although non-baryonic particles cannot be excluded, only "Big Bang" cosmology predicts an appreciable fraction of such alternate forms. As more counter-physics hypotheses are added to fit observation to the expanding universe assumption, a classical physics alternative proffers dark matter interactive red shifts normally correlated with distance. The cosmic microwave background results from size-independent thermal plateau radiation that emanates from dark matter gravitationally drawn into the Galaxy.
Dynamical Structure of Baryons
Aleksejevs, A
2013-01-01
Compton scattering offers a unique opportunity to study the dynamical structure of hadrons over a wide kinematic range, with polarizabilities characterizing the hadron active internal degrees of freedom. We present calculations and detailed analysis of electric and magnetic and the spin-dependent dynamical polarizabilities for the lowest in mass SU(3) octet of baryons. These extensive calculations are made possible by the recent implementation of semi-automatized calculations in chiral perturbation theory which allows evaluating polarizabilities from Compton scattering up to next-to-the-leading order. The dependencies for the range of photon energies covering the majority of the meson photoproduction channels are analyzed.
Pati, Jogesh C.; Salam, Abdus
We suggest that baryon-number conservation may not be absolute and that an integrally charged quark may disintegrate into two leptons and an antilepton with a coupling strength G Bmp2≲ 10-9. On the other hand, if quarks are much heavier than low-lying hadrons, the decay of a three-quark system like the proton is highly forbidden (proton lifetime ≳ 1028 y). Motivation for these ideas appears to arise within a unified theory of hadrons and leptons and their gauge interactions. We emphasize the consequences of such a possibility for real quark searches.
Stochastic isocurvature baryon fluctuations, baryon diffusion, and primordial nucleosynthesis
Kurki-Suonio, H; Mathews, G J; Kurki-Suonio, Hannu; Jedamzik, Karsten; Mathews, Grant J
1996-01-01
We examine effects on primordial nucleosynthesis from a truly random spatial distribution in the baryon-to-photon ratio (\\eta). We generate stochastic fluctuation spectra characterized by different spectral indices and root-mean-square fluctuation amplitudes. For the first time we explicitly calculate the effects of baryon diffusion on the nucleosynthesis yields of such stochastic fluctuations. We also consider the collapse instability of large-mass-scale inhomogeneities. Our results are generally applicable to any primordial mechanism producing fluctuations in \\eta which can be characterized by a spectral index. In particular, these results apply to primordial isocurvature baryon fluctuation (PIB) models. The amplitudes of scale-invariant baryon fluctuations are found to be severely constrained by primordial nucleosynthesis. However, when the \\eta distribution is characterized by decreasing fluctuation amplitudes with increasing length scale, surprisingly large fluctuation amplitudes on the baryon diffusion ...
Algebraic Models of Hadron Structure; 2, Strange Baryons
Bijker, R; Leviatan, A
2000-01-01
The algebraic treatment of baryons is extended to strange resonances. Within this framework we study a collective string-like model in which the radial excitations are interpreted as rotations and vibrations of the strings. We derive a mass formula and closed expressions for strong and electromagnetic decay widths and use these to analyze the available experimental data.
Anomalous Dimensions of Conformal Baryons
DEFF Research Database (Denmark)
Pica, Claudio; Sannino, Francesco
2016-01-01
We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within...
Bijker, R; Leviatan, A
1993-01-01
We propose an algebraic description of the geometric structure of baryons in terms of the algebra $U(7)$. We construct a mass operator that preserves the threefold permutational symmetry and discuss a collective model of baryons with the geometry of an oblate top.
Anomalous Dimensions of Conformal Baryons
DEFF Research Database (Denmark)
Pica, Claudio; Sannino, Francesco
2016-01-01
We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within the $...
Baryon stopping probes deconfinement
Wolschin, Georg
2016-08-01
Stopping and baryon transport in central relativistic Pb + Pb and Au + Au collisions are reconsidered with the aim to find indications for the transition from hadronic to partonic processes. At energies reached at the CERN Super Proton Synchrotron ( √{s_{NN}} = 6.3-17.3 GeV) and at RHIC (62.4 GeV) the fragmentation-peak positions as obtained from the data depend linearly on the beam rapidity and are in agreement with earlier results from a QCD-based approach that accounts for gluon saturation. No discontinuities in the net-proton fragmentation peak positions occur in the expected transition region from partons to hadrons at 6-10GeV. In contrast, the mean rapidity loss is predicted to depend linearly on the beam rapidity only at high energies beyond the RHIC scale. The combination of both results offers a clue for the transition from hard partonic to soft hadronic processes in baryon stopping. NICA results could corroborate these findings.
Electromagnetic properties of baryons
Energy Technology Data Exchange (ETDEWEB)
Haupt, C.
2006-07-01
Static observables of bound state systems in field theoretic descriptions are usually extracted from form factors in the limit of vanishing squared four-momentum transfer of the probing exchange particle. On the other hand, static properties in nonrelativistic quantum mechanics can be formulated by means of expectation values involving essentially scalar products of wave functions. The main objective of this work is to show that a synthesis of both approaches is indeed possible - at least if certain restrictions are made to the kind of interactions between the constituents of the bound system - leading to new insights into the structure of static properties. The focus lies especially on the charge radii and magnetic moments of baryons described within a covariant constituent quark model having its field theoretic foundations in the Bethe-Salpeter equation. The current matrix element in the Breit frame between the vertex functions is derived. The charge radius and magnetic moment of a bound three-fermion system is then derived by starting from their usual definition from form factors and in case of the charge radius also from the well-known radius of a charge distribution in classical electrodynamics. In both cases the static limit at the photon point is taken analytically and subsequently the integration over the relative energy variables is done. Finally the vertex functions are replaced by Salpeter amplitudes and the expression is symmetrized over the three fermions. The final results express the charge radius and magnetic moment of the three-fermion system as expectation values with respect to Salpeter amplitudes. The numerical implementation of the analytic results is done within a covariant constituent quark model with quark confinement and a residual instanton interaction accounting for the fine structure of the observed mass spectra. The Salpeter amplitudes which where obtained by solving the Salpeter equation are used to compute the expectation values of
Observation of the sigma_b baryons at CDF
Energy Technology Data Exchange (ETDEWEB)
Pursley, Jennifer M.; /Johns Hopkins U.
2007-03-01
We present a measurement of four new bottom baryons in proton-antiproton collisions with a center of mass energy of 1.96 TeV. Using 1.1 fb{sup -1} of data collected by the CDF II detector, we observe four {Lambda}{sup 0}{sub b}{pi}{+-} resonances in the fully reconstructed decay mode {Lambda}{sup 0}{sub b} {yields} {Lambda}{sup +}{sub c}{pi}{sup -}, where {Lambda}{sup +}{sub c} {yields} pK{sup -}{pi}{sup +}. The probability for the background to produce a similar or larger signal is less than 8.3 x 10{sup -8}, corresponding to a significance of greater than 5.2 {sigma}. We interpret these baryons as the {Sigma}{sub b}{sup (*){+-}} baryons.
Study of Baryon Spectroscopy Using a New Potential Form
Directory of Open Access Journals (Sweden)
L. I. Abou-Salem
2014-01-01
Full Text Available In the present work, the nonrelativistic quark model is applied to study baryon systems, where the constituent quarks are bound by a suitable hyper central potential. We proposed a new phenomenological form of the interaction potential, digamma-type potential. Using the Jacobi coordinates, the three-body wave equation is solved numerically to calculate the resonance states of the N, Δ, Λ, and Σ baryon systems. The present model contains only two adjustable parameters in addition to the quark masses. Our theoretical calculations are compared to the available experimental data and Cornell potential results. The description of the spectrum shows that the ground states of the considered light and strange baryon spectra are in general well reproduced.
Interactions between Octet Baryons in the SU_6 Quark model
Fujiwara, Y; Nakamoto, C; Suzuki, Y
2001-01-01
The baryon-baryon interactions for the complete baryon octet (B_8) are investigated in a unified framework of the resonating-group method, in which the spin-flavor SU_6 quark-model wave functions are employed. Model parameters are determined to reproduce properties of the nucleon-nucleon system and the low-energy cross section data for the hyperon-nucleon interaction. We then proceed to explore B_8 B_8 interactions in the strangeness S=-2, -3 and -4 sectors. The S-wave phase-shift behavior and total cross sections are systematically understood by 1) the spin-flavor SU_6 symmetry, 2) the special role of the pion exchange, and 3) the flavor symmetry breaking.
Measurement of b-Baryons with the CDF II detector
Energy Technology Data Exchange (ETDEWEB)
Heuser, Joachim; /Karlsruhe U., EKP
2007-10-01
We report the observation of new bottom baryon states. The most recent result is the observation of the baryon {Xi}{sub b}{sup -} through the decay {Xi}{sub b}{sup -} {yields} J/{psi}{Xi}{sup -}. The significance of the signal corresponds to 7.7{sigma} and the {Xi}{sub b}{sup -} mass is measured to be 5792.9{+-}2.5(stat.){+-}1.7(syst.) MeV/c{sup 2}. In addition we observe four resonances in the {Lambda}{sub b}{sup 0}{pi}{sup {+-}} spectra, consistent with the bottom baryons {Sigma}{sub b}{sup (*){+-}}. All observations are in agreement with theoretical expectations.
Baryon Spectroscopy - Recent Results from the CBELSA/TAPS Experiment
Hartmann, Jan
2016-01-01
One of the remaining challenges within the standard model is to gain a good understanding of QCD in the non-perturbative regime. One key step toward this aim is baryon spectroscopy, investigating the spectrum and the properties of baryon resonances. To get access to resonances with small $\\pi N$ partial width, photoproduction experiments provide essential information. In order to extract the contributing resonances, partial wave analyses need to be performed. Here, a complete experiment is required to unambiguously determine the contributing amplitudes. This involves the measurement of carefully chosen single and double polarization observables. The CBELSA/TAPS experiment with a longitudinally or transversely polarized target and an energy tagged, linearly or circularly polarized photon beam allows the measurement of a large set of polarization observables. Due to its good energy resolution, high detection efficiency for photons, and the nearly complete solid angle coverage it is ideally suited for the measur...
Decays of J/psi (3100) to baryon final states
Energy Technology Data Exchange (ETDEWEB)
Eaton, M.W.
1982-05-01
We present results for the decays of psi(3100) into baryon and hyperon final states. The sample studied here consists of 1.3 million produced psi decays. The decays into nonstrange baryons agree well with currently established results, but with better statistics. In addition, significant resonance formation in multibody final states is observed. The decay psi ..-->.. anti pp..gamma.., the first direct photon decay of the psi involving baryons in the final state, is presented and the theoretical implications of the decays are briefly explored. Several new decays of the psi involving strange baryons are explored, including the first observations of three body final states involving hyperons. The I-spin symmetry of the strong decay psi ..-->.. baryons has clearly been observed. The reduced matrix elements for psi ..-->.. B anti B are presented for final states of different SU(3) content. The B/sub 8/ anti B/sub 8/ results are in excellent agreement with the psi being an SU(3) singlet as are the results for psi ..-->.. B/sub 10/ anti B/sub 10/. We present the first evidence for the SU(3) violating decays of the type psi ..-->.. B/sub 8/ anti B/sub 10/ + c.c.. Angular distributions for psi ..-->.. B/sub 8/ anti B/sub 8/ are presented and compared with theoretical predictions. Statistics are limited, but the data tends to prefer other than a 1 + Cos/sup 2/theta distribution.
Anomalous Dimensions of Conformal Baryons
Pica, Claudio
2016-01-01
We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small for a wide range of number of flavours. We also find that this is always smaller than the anomalous dimension of the fermion mass operator. These findings challenge the partial compositeness paradigm.
Algebraic Approach to Baryon Structure
Leviatan, A
1996-01-01
We present an algebraic approach to the internal structure of baryons in terms of three constituents. We investigate a collective model in which the nucleon is regarded as a rotating and vibrating oblate top with a prescribed distribution of charges and magnetization. We contrast the collective and single-particle descriptions of baryons and compare the predictions of the model with existing data on masses, electromagnetic elastic and transition form factors and strong decays widths.
Baryon spectrum and chiral dynamics
Glozman, L Ya
1995-01-01
New results on baryon structure and spectrum developed in collaboration with Dan Riska [1-4] are reported. The main idea is that beyond the chiral symmetry spontaneous breaking scale light and strange baryons should be considered as systems of three constituent quarks with an effective confining interaction and a chiral interaction that is mediated by the octet of Goldstone bosons (pseudoscalar mesons) between the constituent quarks.
Strangeness as a probe to baryon-rich QCD matter at NICA
Energy Technology Data Exchange (ETDEWEB)
Fukushima, Kenji [The University of Tokyo, Department of Physics, Bunkyo-ku, Tokyo (Japan)
2016-08-15
We elucidate a prospect of strangeness fluctuation measurements in the heavy-ion collision at NICA energies. The strangeness fluctuation is sensitive to quark deconfinement. At the same time strangeness has a strong correlation with the baryon number under the condition of vanishing net strangeness, which leads to an enhancement of Λ{sup 0}, Ξ{sup 0}, Ξ{sup -}, and K{sup +} at high baryon density. The baryon density is maximized around the NICA energies, and strangeness should be an ideal probe to investigate quark deconfinement phenomena of baryon-rich QCD matter created at NICA. We also utilize the hadron resonance gas model to estimate a mixed fluctuation of strangeness and baryon number. (orig.)
Galaxy Cluster Baryon Fractions Revisited
Gonzalez, Anthony H; Zabludoff, Ann I; Zaritsky, Dennis
2013-01-01
We measure the baryons contained in both the stellar and hot gas components for twelve galaxy clusters and groups at z~0.1 with M=1-5e14 Msun. This paper improves upon our previous work through the addition of XMM data, enabling measurements of the total mass and masses of each major baryonic component --- ICM, intracluster stars, and stars in galaxies --- for each system. We recover a relation for the stellar mass versus halo mass consistent with our previous result. We confirm that the partitioning of baryons between the stellar and hot gas components is a strong function of M500; the fractions of total mass in stars and X-ray gas within r500 scale as M500^-0.45 and M500^0.26, respectively. We also confirm that the combination of the BCG and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. We find a weak, but statistically significant, dependence of the total baryon fraction upon halo mass, scaling as M500^0.16. For M500>2e14, the total baryon fr...
Quark-Model Baryon-Baryon Interaction and its Applications to Hypernuclei
Fujiwara, Y; Suzuki, Y; Kohno, M; Miyagawa, K
2004-01-01
The quark-model baryon-baryon interaction fss2, proposed by the Kyoto-Niigata group, is a unified model for the complete baryon octet (B_8=N, Lambda, Sigma and Xi), which is formulated in a framework of the (3q)-(3q) resonating-group method (RGM) using the spin-flavor SU_6 quark-model wave functions and effective meson-exchange potentials at the quark level. Model parameters are determined to reproduce properties of the nucleon-nucleon system and the low-energy cross section data for the hyperon-nucleon scattering. Due to the several improvements including the introduction of vector-meson exchange potentials, fss2 has achieved very accurate description of the NN and YN interactions, comparable to various one-boson exchange potentials. We review the essential features of fss2 and our previous model FSS, and their predictions to few-body systems in confrontation with the available experimental data. Some characteristic features of the B_8 B_8 interactions with the higher strangeness, S=-2, -3, -4, predicted by ...
Molecular dynamics simulation for the baryon-quark phase transition at finite baryon density
Energy Technology Data Exchange (ETDEWEB)
Akimura, Y. [Saitama University, Department of physics, Sakura-Ku, Saitama City (Japan); Japan Atomic Energy Research Institute, Advanced Science Research Center, Tokai (Japan); Maruyama, T.; Chiba, S. [Japan Atomic Energy Research Institute, Advanced Science Research Center, Tokai (Japan); Yoshinaga, N. [Saitama University, Department of physics, Sakura-Ku, Saitama City (Japan)
2005-09-01
We study the baryon-quark phase transition in the molecular dynamics (MD) of the quark degrees of freedom at finite baryon density. The baryon state at low baryon density, and the deconfined quark state at high baryon density are reproduced. We investigate the equations of state of matters with different u-d-s compositions. It is found that the baryon-quark transition is sensitive to the quark width. (orig.)
Spectrum and Structure of Excited Baryons with CLAS
Burkert, Volker D
2016-01-01
In this contribution we discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels $\\gamma p \\to K^+ \\Lambda$ and $\\gamma p \\to K^+ \\Sigma^0$. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as $\\gamma p \\to p \\omega$ and $\\gamma p \\to \\phi p$ are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up si...
Evidence for a Narrow Anti-Charmed Baryon State
Aktas, A; Anthonis, T; Asmone, A; Babaev, A; Backovic, S; Bähr, J; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, C; Berger, N; Berndt, T; Bizot, J C; Böhme, J; Boenig, M O; Boudry, V; Bracinik, J; Brisson, V; Broker, H B; Brown, D P; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Caron, S; Cassol-Brunner, F; Cerny, K; Chekelian, V; Collard, Caroline; Contreras, J G; Coppens, Y R; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; Delcourt, B; Demirchyan, R; de Roeck, A; Desch, Klaus; De Wolf, E A; Diaconu, C; Dingfelder, J; Dodonov, V; Dubak, A; Duprel, C; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Ellerbrock, M; Elsen, E; Erdmann, M; Erdmann, W; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Ferencei, J; Fleischer, M; Fleischmann, P; Fleming, Y H; Flucke, G; Flügge, G; Fomenko, A; Foresti, I; Formánek, J; Franke, G; Frising, G; Gabathuler, Erwin; Gabathuler, K; Garutti, E; Garvey, J; Gayler, J; Gerhards, R; Gerlich, C; Ghazaryan, S; Glazov, A; Görlich, L; Gogitidze, N; Gorbounov, S; Grab, C; Grässler, Herbert; Greenshaw, T; Gregori, M; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Haller, J; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Henshaw, O; Heremans, R; Herrera-Corral, G; Herynek, I; Heuer, R D; Hildebrandt, M; Hiller, K H; Hoting, P; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, H; Kant, D; Kapichine, M; Karlsson, M; Katzy, J; Keller, N; Kennedy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Koblitz, B; Korbel, V; Kostka, P; Koutouev, R; Kropivnitskaya, A; Kroseberg, J; Kuckens, J; Kuhr, T; Landon, M P J; Lange, W; Lastoviicka, T; Laycock, P; Lebedev, A; Leiner, B; Lemrani, R; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; List, B; Lobodzinska, E; Loktionova, N A; López-Fernandez, R; Lubimov, V; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marks, J; Marshall, R; Martisikova, M; Martyn, H U; Maxfield, S J; Meer, D; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Michine, S; Mikocki, S; Milcewicz, I; Milstead, D; Mohamed, A; Moreau, F; Morozov, A; Morozov, I; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nagovizin, V; Naroska, Beate; Naumann, J; Naumann, T; Newman, P R; Niebuhr, C B; Nikiforov, A; Nikitin, D K; Nowak, G; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Ossoskov, G; Ozerov, D; Pascaud, C; Patel, G D; Peez, M; Pérez, E; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Pöschl, R; Portheault, B; Povh, B; Raicevic, N; Ratiani, Z; Reimer, P; Reisert, B; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A A; Rurikova, Z; Rusakov, S V; Rybicki, K; Sankey, D P C; Sauvan, E; Schatzel, S; Scheins, J; Schilling, F P; Schleper, P; Schmidt, S; Schmitt, S; Schneider, M; Schoeffel, L; Schöning, A; Schröder, V; Schultz-Coulon, H C; Schwanenberger, C; Sedlak, K; Sefkow, F; Shevyakov, I; Shtarkov, L N; Sirois, Y; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Spitzer, H; Stamen, R; Stella, B; Stiewe, J; Strauch, I; Straumann, U; Tchoulakov, V; Thompson, G; Thompson, P D; Tomasz, F; Traynor, D; Truöl, P; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Uraev, A; Urban, M; Usik, A; Utkin, D; Valkár, S; Valkárová, A; Vallée, C; Van Mechelen, P; Van, N; Remortel; Vargas-Trevino, A; Vazdik, Ya A; Veelken, C; Vest, A; Vinokurova, S; Volchinski, V; Wacker, K; Wagner, J; Weber, G; Weber, R; Wegener, D; Werner, C; Werner, N; Wessels, M; Wessling, B; Winter, G G; Wissing, C; Woerling, E E; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhokin, A; Zohrabyan, H G; Zomer, F
2004-01-01
A narrow resonance in D*- p and D*+ pbar invariant mass combinations is observed in inelastic electron-proton collisions at centre-of-mass energies of 300 GeV and 320 GeV at HERA. The resonance has a mass of 3099 \\pm 3 (stat.) \\pm 5 (syst.) MeV and a measured Gaussian width of 12 \\pm 3 (stat.) MeV, compatible with the experimental resolution. The resonance is interpreted as an anti-charmed baryon with a minimal constituent quark composition of uuddcbar, together with the charge conjugate.
Baryons and baryonic matter in four-fermion interaction models
Energy Technology Data Exchange (ETDEWEB)
Urlichs, K.
2007-02-23
In this work we discuss baryons and baryonic matter in simple four-fermion interaction theories, the Gross-Neveu model and the Nambu-Jona-Lasinio model in 1+1 and 2+1 space-time dimensions. These models are designed as toy models for dynamical symmetry breaking in strong interaction physics. Pointlike interactions (''four-fermion'' interactions) between quarks replace the full gluon mediated interaction of quantum chromodynamics. We consider the limit of a large number of fermion flavors, where a mean field approach becomes exact. This method is formulated in the language of relativistic many particle theory and is equivalent to the Hartree-Fock approximation. In 1+1 dimensions, we generalize known results on the ground state to the case where chiral symmetry is broken explicitly by a bare mass term. For the Gross-Neveu model, we derive an exact self-consistent solution for the finite density ground state, consisting of a one-dimensional array of equally spaced potential wells, a baryon crystal. For the Nambu- Jona-Lasinio model we apply the derivative expansion technique to calculate the total energy in powers of derivatives of the mean field. In a picture akin to the Skyrme model of nuclear physics, the baryon emerges as a topological soliton. The solution for both the single baryon and dense baryonic matter is given in a systematic expansion in powers of the pion mass. The solution of the Hartree-Fock problem is more complicated in 2+1 dimensions. In the massless Gross-Neveu model we derive an exact self-consistent solution by extending the baryon crystal of the 1+1 dimensional model, maintaining translational invariance in one spatial direction. This one-dimensional configuration is energetically degenerate to the translationally invariant solution, a hint in favor of a possible translational symmetry breakdown by more general geometrical structures. In the Nambu-Jona-Lasinio model, topological soliton configurations induce a finite baryon
DEFF Research Database (Denmark)
an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...... theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall perspective...
Multiplicity fluctuation and correlation of identified baryons in a quark combination model
Song, Jun; Li, Hai-hong; Wang, Rui-qin; Shao, Feng-lan
2017-01-01
The dynamical multiplicity fluctuations and correlations of identified baryons and antibaryons produced by the hadronization of a bulk quark system are systematically studied in a quark combination model. Starting from the most basic dynamics of the quark combination which is necessary for multiplicity study, we analyze moments (variance, skewness, and kurtosis) of inclusive multiplicity distributions of identified baryons, two-baryon multiplicity correlations, and baryon-antibaryon multiplicity correlations after the hadronization of a quark system with given quark number and antiquark number. We obtain a series of interesting results, e.g., binomial behavior of multiplicity moments, coinciding flavor-dependent two-baryon correlation, and universal baryon-antibaryon correlation, which can be regarded as general features of the quark combination. We further take into account correlations and fluctuations of quark numbers before hadronization and study their influence on multiple production of baryons and antibaryons. We find that quark number fluctuations and flavor conservation lead to a series of important results such as the negative p Ω¯ + multiplicity correlation and universal two-baryon correlations. We also study the influence of resonance decays in order to compare our results with future experimental data in ultrarelativistic heavy ion collisions at the Large Hadron Collider.
The search for exotic baryons at the HERMES experiment
Energy Technology Data Exchange (ETDEWEB)
Deconinck, Wouter
2008-07-15
One of the interesting questions of Quantum Chromodynamics, the theory that governs the interactions between quarks and gluons, has been whether it is possible to observe hadrons which can not be explained as a combination of only two or three valence quarks. In numerous searches the existence of these exotic hadrons could not be confirmed. Recently, calculations based on the quark soliton model predicted the narrow exotic baryons {theta}{sup +} and {xi}{sup --}. A narrow resonance identified as the {theta}{sup +} was observed by several experiments at the predicted mass of 1540 MeV, but later followed by several dedicated experiments that could not confirm these positive results. At the HERMES experiment a search for the quasi-real photoproduction of the exotic baryon {theta}{sup +} on a deuterium target and the subsequent decay through pK{sup 0}{sub S} {yields} p{pi}{sup +}{pi}{sup -} revealed a narrow resonance in the pK{sup 0}{sub S} invariant mass distribution at 1528 MeV. In the search for the corresponding antiparticle {xi}{sup --} the result is consistent with zero events. In this thesis we present the search for the exotic baryon {xi}{sup --} on a deuterium target in the data sample used for the observation of the {theta}{sup +}. An upper limit on the cross section of the exotic baryon {xi}{sup --} is determined. The search for the exotic baryon {theta}{sup +} on hydrogen and deuterium targets at the HERMES experiment is extensively discussed. The event mixing method can be used to estimate the distribution of background events. Several difficulties with this method were addressed, but the background description in the case of the exotic baryon {theta}{sup +} remains unconvincing. Between the years 2002 and 2005 the HERMES experiment operated with a magnetic holding field around the hydrogen target. A method for the reconstruction of displaced vertices in this field was developed. The data collected during the years 2006 and 2007 offer an integrated
Quark confinement mechanism for baryons
Goncharov, Yu P
2013-01-01
The confinement mechanism proposed earlier and then successfully applied to meson spectroscopy by the author is extended over baryons. For this aim the wave functions of baryons are built as tensorial products of those corresponding to the 2-body problem underlying the confinement mechanism of two quarks. This allows one to obtain the Hamiltonian of the quark interactions in a baryon and, accordingly, the possible energy spectrum of the latter. Also one may construct the electric and magnetic form factors of baryon in a natural way which entails the expressions for the root-mean-square radius and anomalous magnetic moment. To ullustrate the formalism in the given Chapter for the sake of simplicity only symmetrical baryons (i.e., composed from three quarks of the same flavours) $\\Delta^{++}$, $\\Delta^{-}$, $\\Omega^-$ are considered. For them the masses, the root-mean-square radii and anomalous magnetic moments are expressed in an explicit analytical form through the parameters of the confining SU(3)-gluonic fi...
Baryon Transition in Holographic QCD
Li, Siwen
2015-01-01
We propose a mechanism of holographic baryon transition in the Sakai-Sugimoto (SS) model: baryons in this model can jump to different states under the mediated effect of gravitons (or glueballs by holography). We consider a time-dependent gravitational perturbation from M5-brane solution of D=11 supergravity and by employing the relations between 11D M-theory and IIA string theory, we get its 10 dimensional counterpart in the SS model. Such a perturbation is received by the D4-branes wrapped on the $S^{4}$ part of the 10D background, namely the baryon vertex. Technically, baryons in the SS model are described by BPST instanton ansatz and their dynamics can be analyzed using the quantum mechanical system in the instanton's moduli space. In this way, different baryonic states are marked by quantum numbers of moduli space quantum mechanics. By holographic spirit, the gravitational perturbation enters the Hamiltonian as a time-dependent perturbation and it is this time-dependent perturbative Hamiltonian produces ...
Molecular Structures in Hidden Charm Meson and Charmed Baryon Spectrum
Fernandez, F; Ortega, P G
2013-01-01
Using a constituent quark model we study the mass and decay channels of meson meson and meson baryon structures in the charm sector. We show that the $X(3872)$ and $X(3940)$ resonances can be described as mixed charmonium-molecular states with $J^{PC}=1^{++}$, whereas the $X(3915)$ and the $Y(3940)$ can be assigned to similar mixed states with $J^{PC}=0^{++}$. In the baryon spectrum we identify the $\\Lambda^+_c(2940)$ as a $D^*N$ molecule with $(I)J^P=(0)3/2^-$ and the recently reported $X_c(3250)$ as a $D^*\\Delta$ resonance with $(I)J^P=(1)5/2^-$ or $(I)J^P=(2)3/2^-$.
Fingerprint of a QCD string in baryon spectra
Energy Technology Data Exchange (ETDEWEB)
Kirchbach, M. [Escuela de Fisica, Universidad Autonoma de Zacatecas, A.P. C-600, 98062 Zacatecas (Mexico)
2001-07-01
Multi-spin valued states of the Rarita-Schwinger type (k/2, k/2) x encircled [(1/2, O) + encircled (0,1/2)] with k = 1, 3, and 5 are found to be realized in the excitation spectra of the light-quark baryons. We conjecture that the above multi-resonance clusters may take their origin from a QCD string described by means of a linear action. (Author)
Density-dependent effective baryon-baryon interaction from chiral three-baryon forces
Petschauer, Stefan; Haidenbauer, Johann; Kaiser, Norbert; Meißner, Ulf-G.; Weise, Wolfram
2017-01-01
A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the ΛN in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the three-body force in symmetric nuclear matter and pure neutron matter on the ΛN interaction. A moderate repulsion that increases with density is found in comparison to the free ΛN interaction.
Density-dependent effective baryon-baryon interaction from chiral three-baryon forces
Petschauer, Stefan; Kaiser, Norbert; Meißner, Ulf-G; Weise, Wolfram
2016-01-01
A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the Lambda-nucleon in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the ...
Dilatons in Dense Baryonic Matter
Lee, Hyun Kyu
2013-01-01
We discuss the role of dilaton, which is supposed to be representing a special feature of scale symmetry of QCD, trace anomaly, in dense baryonic matter. The idea that the scale symmetry breaking of QCD is responsible for the spontaneous breaking of chiral symmetry is presented along the similar spirit of Freund-Nambu model. The incorporation of dilaton field in the hidden local symmetric parity doublet model is briefly sketched with the possible role of dilaton at high density baryonic matter, the emergence of linear sigma model in dilaton limit.
Decuplet baryons in hot medium
Azizi, K
2016-01-01
The thermal properties of the light decuplet baryons are investigated in the framework of the thermal QCD sum rules. In particular, the behavior of the mass and residue of the $\\Delta$, $\\Sigma^{*}$, $\\Xi^{*}$ and $\\Omega$ baryons with respect to temperature are analyzed taking into account the additional operators coming up in the Wilson expansion at finite temperature. It is found that the mass and residue of these particles remain overall unaffected up to $T\\simeq150~MeV$ but, after this point, they start to diminish, considerably.
Deforming baryons into confining strings
Hartnoll, S A; Hartnoll, Sean A.; Portugues, Ruben
2004-01-01
We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in ${\\mathcal{N}}=1$ gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G_2 holonomy M theory background. The interpretation of these solutions as deformed baryons/confining strings is not as straightforward.
Bijker, R; Leviatan, A
1997-01-01
We study strong decays of nonstrange baryons by making use of the algebraic approach to hadron structure. Within this framework we derive closed expressions for decay widths in an elementary-meson emission model and use these to analyze the experimental data for $N^* \\rightarrow N + \\pi$, $N^* + \\pi$, $\\Delta^* \\rightarrow \\Delta + \\pi$ and $\\Delta^* \\rightarrow \\Delta +
Search for Popcorn Mesons in Events with Two Charmed Baryons
Energy Technology Data Exchange (ETDEWEB)
Hartfiel, Brandon; /SLAC
2006-07-07
The physics of this note is divided into two parts. The first part measures the {Lambda}{sub c} {yields} {pi}kp continuum momentum spectrum at a center of mass energy of 10.54 GeV/c. The data sample consists of 15,400 {Lambda}{sub c} baryons from 9.46 fb{sup -1} of integrated luminosity. With more than 13 times more data than the best previous measurement, we are able to exclude some of the simpler, one parameter fragmentation functions. In the second part, we add the {Lambda}{sub c} {yields} K{sup 0}p mode, and look for events with a {Lambda}{sub c}{sup +} and a {bar {Lambda}}{sub c}{sup -} in order to look for ''popcorn'' mesons formed between the baryon and antibaryon. We add on-resonance data, with a kinematic cut to eliminate background from B decays, as well as BaBar run 3 and 4 data to increase the total data size to 219.70 fb{sup -1}. We find 619 events after background subtraction. After a subtraction of 1.06 {+-} .09 charged pions coming from decays of known resonances to {Lambda}{sub c} + {eta}{pi}, we are left with 2.63 {+-} .21 additional charged pions in each of these events. This is significantly higher than the .5 popcorn mesons per baryon pair used in the current tuning of Pythia 6.2, the most widely used Monte Carlo generator. The extra mesons we find appear to be the first direct evidence of popcorn mesons, although some of them could be arising from hypothetical unresolved, unobserved charmed baryon resonances contributing decay mesons to our data. To contribute a significant fraction, this hypothesis requires a large number of such broad unresolved states and seems unlikely, but can not be completely excluded.
Baryon Number Current in Chiral Soliton Model
Institute of Scientific and Technical Information of China (English)
LiXiguo
2003-01-01
Last year two exotic and narrow baryons, θ+(1540) and Ξ3/2--(1862), which are pentaquark states have been reported by several group. Their minimal quark content are uudds and ddssu, respectively. The θ+(1540) baryon was observed in few independent experiments. Its hypercharge, Y=2. The exotic baryon is an isosinglet. The Ξ3/2--(1862) baryon was also observed in the Ξ-π- invariant mass spectrum in proton-proton scattering at the CERN SPS . The search of exotic baryons was motivated by the flavor SU(3) extension of
Study of ψ(3770 decaying to baryon anti-baryon pairs
Directory of Open Access Journals (Sweden)
Li-Gang Xia
2016-05-01
Full Text Available To study the decays of ψ(3770 going to baryon anti-baryon pairs (BB¯, all available experiments of measuring the cross sections of e+e−→BB¯ at center-of-mass energy ranging from 3.0 GeV to 3.9 GeV are combined. To relate the baryon octets, a model based on the SU(3 flavor symmetry is used and the SU(3 breaking effects are also considered. Assuming the electric and magnetic form factors are equal (|GE|=|GM|, a global fit including the interference between the QED process and the resonant process is performed. The branching fraction of ψ(3770→BB¯ is determined to be (2.4±0.8±0.3×10−5, (1.7±0.6±0.1×10−5, (4.5±0.9±0.1×10−5, (4.5±0.9±0.1×10−5, (2.0±0.7±0.1×10−5, and (2.0±0.7±0.1×10−5 for B=p,Λ,Σ+,Σ0,Ξ− and Ξ0, respectively, where the first uncertainty is from the global fit and the second uncertainty is the systematic uncertainty due to the assumption |GE|=|GM|. They are at least one order of magnitude larger than a simple scaling of the branching fraction of J/ψ/ψ(3686→BB¯.
Baryon Spectroscopy Through Partial-Wave Analysis and Meson Photoproduction
Energy Technology Data Exchange (ETDEWEB)
Manley, D. Mark [Kent State Univ., Kent, OH (United States)
2016-09-08
The principal goal of this project is the experimental and phenomenological study of baryon spectroscopy. The PI's group consists of himself and three graduate students. This final report summarizes research activities by the PI's group during the period 03/01/2015 to 08/14/2016. During this period, the PI co-authored 11 published journal papers and one proceedings article and presented three invited talks. The PI's general interest is the investigation of the baryon resonance spectrum up to masses of ~ 2 GeV. More detail is given on two research projects: Neutral Kaon Photoproduction and Partial-Wave Analyses of γp → η p, γn → η n, and γp → K⁺ Λ.
Net baryon fluctuations from a crossover equation of state
Energy Technology Data Exchange (ETDEWEB)
Kapusta, J.; Albright, M. [University of Minnesota, School of Physics and Astronomy, Minneapolis, MN (United States); Young, C. [Michigan State University, National Superconducting Cyclotron Laboratory, East Lansing, MI (United States)
2016-08-15
We have constructed an equation of state which smoothly interpolates between an excluded-volume hadron resonance gas at low energy density to a plasma of quarks and gluons at high energy density. This crossover equation of state agrees very well with lattice calculations at both zero and nonzero baryon chemical potential. We use it to compute the variance, skewness, and kurtosis of fluctuations of baryon number, and compare to measurements of proton number fluctuations in central Au-Au collisions as measured by the STAR Collaboration in a beam energy scan at the Relativistic Heavy-Ion Collider. The crossover equation of state can reproduce the data if the fluctuations are frozen out at temperatures well below than the average chemical freeze-out. (orig.)
Net Baryon Fluctuations from a Crossover Equation of State
Kapusta, J; Young, C
2016-01-01
We have constructed an equation of state which smoothly interpolates between an excluded volume hadron resonance gas at low energy density to a plasma of quarks and gluons at high energy density. This crossover equation of state agrees very well with lattice calculations at both zero and nonzero baryon chemical potential. We use it to compute the variance, skewness, and kurtosis of fluctuations of baryon number, and compare to measurements of proton number fluctuations in central Au-Au collisions as measured by the STAR collaboration in a beam energy scan at the Relativistic Heavy Ion Collider. The crossover equation of state can reproduce the data if the fluctuations are frozen out at temperatures well below than the average chemical freeze-out.
CP violation in multibody decays of beauty baryons
Durieux, Gauthier
2016-01-01
Beauty baryons are being observed in large number in the LHCb detector. The rich kinematics of their multibody decays are therefore becoming accessible and provide us with new opportunities to search for CP violation. We analyse the angular distributions of some three- and four-body decays of spin-$1/2$ baryons using the Jacob-Wick helicity formalism. The asymmetries that provide access to small differences of CP-odd phases between decay amplitudes of identical CP-even phases are notably discussed. The understanding gained on processes featuring specific resonant intermediate states allows us to establish which asymmetries are relevant for what purpose. It is for instance shown that some CP-odd angular asymmetries measured by the LHCb collaboration in the $\\Lambda_b \\to \\Lambda\\,\\varphi \\to p\\,\\pi\\, K^+ K^-$ decay are expected to vanish identically.
CP violation in multibody decays of beauty baryons
Durieux, Gauthier
2016-10-01
Beauty baryons are being observed in large numbers in the LHCb detector. The rich kinematic distributions of their multibody decays are therefore becoming accessible and provide us with new opportunities to search for CP violation. We analyse the angular distributions of some three- and four-body decays of spin-1/2 baryons using the Jacob-Wick helicity formalism. The asymmetries that provide access to small differences of CP-odd phases between decay amplitudes of identical CP-even phases are notably discussed. The understanding gained on processes featuring specific resonant intermediate states allows us to establish which asymmetries are relevant for what purpose. It is for instance shown that some CP-odd angular asymmetries measured by the LHCb collaboration in the Λ b → Λ φ → p π K + K - decay are expected to vanish identically.
Observation of the Heavy Baryons Sigma b and Sigma b*.
Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; 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; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, 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; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; 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; Dörr, C; 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, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; 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; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; 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Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; 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; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; 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; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; 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; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; 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; Zhou, J; Zucchelli, S
2007-11-16
We report an observation of new bottom baryons produced in pp collisions at the Tevatron. Using 1.1 fb(-1) of data collected by the CDF II detector, we observe four Lambda b 0 pi+/- resonances in the fully reconstructed decay mode Lambda b 0-->Lambda c + pi-, where Lambda c+-->pK* pi+. We interpret these states as the Sigma b(*)+/- baryons and measure the following masses: m Sigma b+=5807.8 -2.2 +2.0(stat.)+/-1.7(syst.) MeV/c2, m Sigma b- =5815.2+/-1.0(stat.)+/-1.7(syst.) MeV/c2, and m(Sigma b*)-m(Sigma b)=21.2-1.9 +2.0(stat.)-0.3+0.4(syst.) MeV/c2.
Heavy Baryon Production and Decay
Dunietz, Isard
1998-01-01
The branching ratio B(Lambda_c -> p K- pi+) normalizes the production and decay of charmed and bottom baryons. At present, this crucial branching ratio is extracted dominantly from B.bar -> baryons analyses. This note questions several of the underlying assumptions and predicts sizable B.bar -> D(*) N N'.bar X transitions, which were traditionally neglected. It predicts B(Lambda_c -> p K- pi+) to be significantly larger (0.07 +/- 0.02) than the world average. Some consequences are briefly mentioned. Several techniques to measure B(Lambda_c -> p K- pi+) are outlined with existing or soon available data samples. By equating two recent CLEO results, an appendix obtains B(D0 -> K- pi+)= 0.035 +/- 0.002, which is somewhat smaller than the current world average.
Mathur, Smita; Williams, Rik J
2007-01-01
We review our attempts to discover lost baryons at low redshift with ``X-ray forest'' of absorption lines from the warm-hot intergalactic medium. We discuss the best evidence to date along the Mrk 421 sightline. We then discuss the missing baryons in the Local Group and the significance of the z=0 absorption systems in X-ray spectra. We argue that the debate over the Galactic vs. extragalactic origin of the z=0 systems is premature as these systems likely contain both components. Observations with next generation X-ray missions such as Constellation-X and XEUS will be crucial to map out the warm-hot intergalactic medium.
Transport coefficients of heavy baryons
Tolos, Laura; Torres-Rincon, Juan M.; Das, Santosh K.
2016-08-01
We compute the transport coefficients (drag and momentum diffusion) of the low-lying heavy baryons Λc and Λb in a medium of light mesons formed at the later stages of high-energy heavy-ion collisions. We employ the Fokker-Planck approach to obtain the transport coefficients from unitarized baryon-meson interactions based on effective field theories that respect chiral and heavy-quark symmetries. We provide the transport coefficients as a function of temperature and heavy-baryon momentum, and analyze the applicability of certain nonrelativistic estimates. Moreover we compare our outcome for the spatial diffusion coefficient to the one coming from the solution of the Boltzmann-Uehling-Uhlenbeck transport equation, and we find a very good agreement between both calculations. The transport coefficients for Λc and Λb in a thermal bath will be used in a subsequent publication as input in a Langevin evolution code for the generation and propagation of heavy particles in heavy-ion collisions at LHC and RHIC energies.
Fujiwara, Y; Kohno, M; Miyagawa, K
2007-01-01
Previously we calculated the binding energies of the triton and hypertriton, using an SU_6 quark-model interaction derived from a resonating-group method of two baryon clusters. In contrast to the previous calculations employing the energy-dependent interaction kernel, we present new results using a renormalized interaction, which is now energy independent and reserves all the two-baryon data. The new binding energies are slightly smaller than the previous values. In particular the triton binding energy turns out to be 8.14 MeV with a charge-dependence correction of the two-nucleon force, 190 keV, being included. This indicates that about 350 keV is left for the energy which is to be accounted for by three-body forces.
Heavy Baryons and QCD Sum Rules
Yakovlev, O I
1996-01-01
We discuss an application of QCD sum rules to the heavy baryons $\\Lambda_Q$ and $\\Sigma_Q$. The predictions for the masses of heavy baryons, residues and Isgur-Wise function are presented. The new results on two loop anomalous dimensions of baryonic currents and QCD radiative corrections (two- and three- loop contributions) to the first two Wilson coefficients in OPE are explicitly presented.
Directory of Open Access Journals (Sweden)
Nasrin Salehi
2016-01-01
Full Text Available The spectrum of ground state and excited baryons (N, Δ, Λ, Σ, Ξ, and Ω particles has been investigated by using nonrelativistic quantum mechanics under the Killingbeck plus isotonic oscillator potentials. Using the Jacobi coordinates, anzast method, and generalized Gürsey Radicati (GR mass formula the three-body-wave equation is solved to calculate the different states of the considered baryons. A comparison between our calculations and the available experimental data shows that the position of the Roper resonances of the nucleon, the ground states, and the excited multiplets up to three GeV are in general well reproduced. Also one can conclude that the interaction between the quark constituents of baryon resonances could be described adequately by using the combination of Killingbeck and isotonic oscillator potentials form.
Baryon Number Violation and String Topologies
Sjöstrand, Torbjörn
2003-01-01
In supersymmetric scenarios with broken R-parity, baryon number violating sparticle decays become possible. In order to search for such decays, a good understanding of expected event properties is essential. We here develop a complete framework that allows detailed studies. Special attention is given to the hadronization phase, wherein the baryon number violating vertex is associated with the appearance of a junction in the colour confinement field. This allows us to tell where to look for the extra (anti)baryon directly associated with the baryon number violating decay.
Magnetic and axial-vector transitions of the baryon antidecuplet
Kim, H -Ch; Göke, K
2007-01-01
We report the recent results of the magnetic transitions and axial-vector transitions of the baryon antidecuplet within the framework of the chiral quark-soliton model. The dynamical model parameters are fixed by experimental data for the magnetic moments of the baryon octet, for the hyperon semileptonic decay constants, and for the singlet axial-vector constant. The transition magnetic moments $\\mu_{\\Lambda\\Sigma}$ and $\\mu_{N\\Delta}$ are well reproduced and other octet-decuplet and octet-antidecuplet transitions are predicted. In particular, the present calculation of $\\mu_{\\Sigma\\Sigma^*}$ is found to be below the upper bound $0.82\\mu_N$ that the SELEX collaboration measured very recently. The results explains consistently the recent findings of a new $N^*$ resonance from the GRAAL and Tohoku LNS group. We also obtain the transition axial-vector constants for the $\\Theta^+\\to KN$ from which the decay width of the $\\Theta^{+}$ pentaquark baryon is determined as a function of the pion-nucleon sigma term $\\Si...
Baryon Form Factors at Threshold
Energy Technology Data Exchange (ETDEWEB)
Baldini Ferroli, Rinaldo [Museo Storico della Fisica e Centro Studi e Ricerche ' E. Fermi' , Rome (Italy); INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Pacetti, Simone [INFN and Dipartimento di Fisica, Universita di Perugia, Perugia (Italy)
2012-04-15
An extensive study of the e{sup +}e{sup -}{yields}pp{sup Macron }BABAR cross section data is presented. Two unexpected outcomes have been found: the modulus of the proton form factor is normalized to one at threshold, i.e.: |G{sup p}(4M{sub p}{sup 2})|=1, as a pointlike fermion, and the resummation factor in the Sommerfeld formula is not needed. Other e{sup +}e{sup -} {yields} baryon-antibaryon cross sections show a similar behavior near threshold.
The 750 GeV LHC diphoton excess from a baryon number conserving string model
Kokorelis, Christos
2016-01-01
We propose an explanation of the LHC data excess resonance of 750 GeV in the diphoton distribution using D-brane models, with gauged baryon number, which accommodate the Standard Model together with vector like exotics. We identify the 750 GeV scalar as either the sneutrino (${\\tilde \
Baryons from quantum mechanics on the Lie group u(3)
Trinhammer, Ole L
2011-01-01
We develop a hamiltonian framework on the Lie group u(3), which we call allospace and which is supposed to carry all the colour dynamics needed to describe the baryon spectrum. The energy eigenstates of our particular Schr\\"odinger equation tends to predict realistically all certain baryon resonances in the NDelta sector. The grouping and number of resonances is predicted by the model from a single fitting of the ground state N(939). The Hamiltonian also contains terms from the group space Laplacian to take care of the superimposed hypercharge and isospin flavour structure. Scarce neutral flavour singlet resonances are predicted and may show up around 4500 MeV in neutron diffraction dissociation experiments above the threshold in the free charm system Sigmacplus(2455)Dminus . We give a controversial prediction of the neutron-proton mass difference as originating in a period doubling of certain parametric states. The group space dynamics communicates with real space via the exterior derivative which projects o...
Conformal symmetry and light flavor baryon spectra
Kirchbach, M
2010-01-01
The degeneracy among parity pairs systematically observed in the N and Delta spectra is interpreted as signature for conformal symmetry realization in the light flavor baryon sector in consequence of AdS/CFT. The case is made by showing that all the observed N and Delta resonances with masses below 2500 MeV distribute fairly well over the first levels of a unitary representation of the conformal group, a representation that covers the spectrum of a quark-diquark system, placed directly on the AdS_5 cone, conformally compactified to R^1*S^3. The free geodesic motion on the S^3 manifold is described by means of the scalar conformal equation there, which is of the Klein-Gordon type. The equation is then gauged by the "curved" Coulomb potential that has the form of a cotangent function. Conformal symmetry is not exact, this because the gauge potential slightly modifies the conformal centrifugal barrier of the free geodesic motion. Thanks to this, the degeneracy between P11-S11 pairs from same level is relaxed, wh...
Baryon and lepton violation in astrophysics.
Kolb, E. W.
The cosmological and astrophysical significance of baryon and lepton number violating process is the subject of this paper. The possibility of baryon-number violating processes in the electroweak transition in the early universe is reviewed. The implications of lepton-number violation via Nambu-Goldstone bosons are discussed in detail.
Baryon number violation in future accelerators
Energy Technology Data Exchange (ETDEWEB)
Tracas, N.D.; Zoupanos, G.
1989-03-30
As a demonstration of the possibility to observe baryon number violation in the next generation of accelerators we present a semirealistic GUT in which proton decay is forbidden and the unification scale is at approx. = 10/sup 3-4/ TeV, leading therefore to observable baryon number violating processes.
(Hybrid) Baryons Quantum Numbers and Adiabatic Potentials
Page, P R
1999-01-01
We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and indicate the flavour, spin, chirality and J^P of (hybrid) baryons. The adiabatic potential is calculated as a function of the quark positions.
Pathways to Rare Baryonic B Decays
Hou Wei Shu; Hou, Wei-Shu
2001-01-01
We point out new ways to search for charmless baryonic B decays: baryon pair production in association with $\\eta^\\prime$ is very likely as large as or even a bit larger than two body $K\\pi/\\pi\\pi$ modes. We extend our argument, in weaker form, to $B\\to \\gamma + X_s$ and $\\ell\
A rotating string model versus baryon spectra
Sonnenschein, Jacob
2014-01-01
We continue our program of describing hadrons as rotating strings with massive endpoints. In this paper we propose models of baryons and confront them with the baryon Regge trajectories. We show that these are best fitted by a model of a single string with a quark at one endpoint and a diquark at the other. This model is preferred over the Y-shaped string model with a quark at each endpoint. We show how the model follows from a stringy model of the holographic baryon which includes a baryonic vertex connected with $N_c$ strings to flavor probe branes. From fitting to baryonic data we find that there is no clear evidence for a non-zero baryonic vertex mass, but if there is such a mass it should be located at one of the string endpoints. The available baryon trajectories in the angular momentum plane $(J,M^2)$, involving light, strange, and charmed baryons, are rather well fitted when adding masses to the string endpoints, with a single universal slope $\\alp = 0.95$ GeV$^{-2}$. Most of the results for the quark...
Baryon form factors in chiral perturbation theory
Kubis, B; Kubis, Bastian; Meissner, Ulf-G.
2001-01-01
We analyze the electromagnetic form factors of the ground state baryon octet to fourth order in relativistic baryon chiral perturbation theory. Predictions for the \\Sigma^- charge radius and the \\Lambda-\\Sigma^0 transition moment are found to be in excellent agreement with the available experimental information. Furthermore, the convergence behavior of the hyperon charge radii is shown to be more than satisfactory.
Exploring the simplest purely baryonic decay processes
Geng, C Q; Rodrigues, Eduardo
2016-01-01
We propose to search for purely baryonic decay processes at the LHCb experiment. In particular, we concentrate on the decay $\\Lambda_b^0\\to p\\bar pn$, which is the simplest purely baryonic decay mode, with solely spin-1/2 baryons involved. We predict its decay branching ratio to be ${\\cal B}(\\Lambda_b^0\\to p\\bar pn)=(2.0^{+0.3}_{-0.2})\\times 10^{-6}$, which is sufficiently large to make the decay mode accessible to LHCb. Though not considered in general, purely baryonic decays could shed light on the puzzle of the baryon number asymmetry in the universe by means of a better understanding of the baryonic nature of our matter world. As such, they constitute a yet unexplored class of decay processes worth investigating. Our study can be extended to the purely baryonic decays of $\\Lambda_b^0\\to p\\bar p \\Lambda$, $\\Lambda_b^0\\to \\Lambda \\bar p\\Lambda$ and $\\Lambda_b^0\\to \\Lambda\\bar \\Lambda\\Lambda$, as well as other similar anti-triplet $b$-baryon decays, such as $\\Xi_b^{0,-}$.
Baryon symmetric big bang cosmology
Stecker, F. W.
1978-01-01
Both the quantum theory and Einsteins theory of special relativity lead to the supposition that matter and antimatter were produced in equal quantities during the big bang. It is noted that local matter/antimatter asymmetries may be reconciled with universal symmetry by assuming (1) a slight imbalance of matter over antimatter in the early universe, annihilation, and a subsequent remainder of matter; (2) localized regions of excess for one or the other type of matter as an initial condition; and (3) an extremely dense, high temperature state with zero net baryon number; i.e., matter/antimatter symmetry. Attention is given to the third assumption, which is the simplest and the most in keeping with current knowledge of the cosmos, especially as pertains the universality of 3 K background radiation. Mechanisms of galaxy formation are discussed, whereby matter and antimatter might have collided and annihilated each other, or have coexisted (and continue to coexist) at vast distances. It is pointed out that baryon symmetric big bang cosmology could probably be proved if an antinucleus could be detected in cosmic radiation.
Pion mean fields and heavy baryons
Yang, Ghil-Seok; Polyakov, Maxim V; Praszałowicz, Michał
2016-01-01
We show that the masses of the lowest-lying heavy baryons can be very well described in a pion mean-field approach. We consider a heavy baryon as a system consisting of the $N_c-1$ light quarks that induce the pion mean field, and a heavy quark as a static color source under the influence of this mean field. In this approach we derive a number of \\textit{model-independent} relations and calculate the heavy baryon masses using those of the lowest-lying light baryons as input. The results are in remarkable agreement with the experimental data. In addition, the mass of the $\\Omega_b^*$ baryon is predicted.
Strangeness in the baryon ground states
Semke, A
2012-01-01
We compute the strangeness content of the baryon ground states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet ground states at different strange quark masses.
Exotic baryon searches in 800 GeV/c pp {yields} pX
Energy Technology Data Exchange (ETDEWEB)
Reyes, M.A.; Felix, J.; Lopez, E.; Moreno, G.; Perez, I.O.; Sosa, M. [Universidad de Guanajuato, Leon, Guanajuato (Mexico); Christian, D.C.; Gottschalk, E.E.; Gutierrez, G.; Wang, M.H.L.S.; Wehmann, A. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Hartouni, E.P. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Knapp, B.C. [Columbia University, Irvington, NY (United States). Nevis Lab.; Kreisler, M.N. [University of Massachusetts, Amherst, MA (United States)
2005-07-01
We report the results of the search for the pentaquark candidates {theta}(1540) and {xi}(1862) using data from Fermilab experiment E690 in the reaction pp {yields} pX at 800 GeV/c. We find no evidence for narrow baryon resonances near 1862 MeV decaying to {xi}{pi}. Also, we find no evidence of a narrow resonance near 1540 MeV decaying to pK{sub s}{sup 0}. (author)
Baryons and baryonic matter in the large Nc and heavy quark limits
Cohen, Thomas D; Ndousse, Kamal K
2011-01-01
This paper explores properties of baryons and finite density baryonic matter in an artificial world in which Nc, the number of colors, is large and the quarks of all species are degenerate and much larger than {\\Lambda}_QCD. It has long been known that in large Nc QCD, baryons composed entirely of heavy quarks are accurately described in the mean-field approximation. However, the detailed properties of baryons in the combined large Nc and heavy quark limits have not been fully explored. Here some basic properties of baryons are computed using a variational approach. At leading order in both the large Nc and heavy quark expansions the baryon mass is computed explicitly as is the baryon form factor. Baryonic matter, the analog of nuclear matter in this artificial world, should also be well described in the mean-field approximation. In the special case where all baryons have an identical spin flavor structure, it is shown that in the formal heavy quark and large Nc limit interactions between baryons are strictly...
Light baryons and their excitations
Eichmann, Gernot; Fischer, Christian S.; Sanchis-Alepuz, Hèlios
2016-11-01
We study ground states and excitations of light octet and decuplet baryons within the framework of Dyson-Schwinger and Faddeev equations. We improve upon similar approaches by explicitly taking into account the momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. We perform calculations in both the three-body Faddeev framework and the quark-diquark approximation in order to assess the impact of the latter on the spectrum. Our results indicate that both approaches agree well with each other. The resulting spectra furthermore agree one-to-one with experiment, provided well-known deficiencies of the rainbow-ladder approximation are compensated for. We also discuss the mass evolution of the Roper and the excited Δ with varying pion mass and analyze the internal structure in terms of their partial wave decompositions.
Diffuse baryonic matter beyond 2020
Markevitch, M; Nulsen, P; Rasia, E; Vikhlinin, A; Kravtsov, A; Forman, W; Brunetti, G; Sarazin, C; Elvis, M; Fabbiano, G; Hornschemeier, A; Brissenden, R
2009-01-01
The hot, diffuse gas that fills the largest overdense structures in the Universe -- clusters of galaxies and a web of giant filaments connecting them -- provides us with tools to address a wide array of fundamental astrophysical and cosmological questions via observations in the X-ray band. Clusters are sensitive cosmological probes. To utilize their full potential for precision cosmology in the following decades, we must precisely understand their physics -- from their cool cores stirred by jets produced by the central supermassive black hole (itself fed by inflow of intracluster gas), to their outskirts, where the infall of intergalactic medium (IGM) drives shocks and accelerates cosmic rays. Beyond the cluster confines lies the virtually unexplored warm IGM, believed to contain most of the baryonic matter in the present-day Universe. As a depository of all the matter ever ejected from galaxies, it carries unique information on the history of energy and metal production in the Universe. Currently planned ma...
Holography, charge and baryon asymmetry
Mongan, T R
2009-01-01
The holographic principle indicates the finite number of bits of information available on the particle horizon describes all physics within the horizon. Linking information on the horizon with Standard Model particles requires a holographic model describing constituents (preons) of Standard Model particles in terms of bits of information on the horizon. Standard Model particles have charges 0, 1/3, 2/3 or 1 in units of the electron charge e, so bits in a preon model must be identified with fractional charge. Energy must be transferred to change the state of a bit, and labeling the low energy state of a bit e/3n and the high energy state -e/3n amounts to defining electric charge. Any such charged preon model will produce more protons than anti-protons at the time of baryogenesis and require baryon asymmetry. It will also produce more positrons than electrons, as suggested by astrophysical measurements.
Baryon-Baryon Interactions ---Nijmegen Extended-Soft-Core Models---
Rijken, T. A.; Nagels, M. M.; Yamamoto, Y.
We review the Nijmegen extended-soft-core (ESC) models for the baryon-baryon (BB) interactions of the SU(3) flavor-octet of baryons (N, Lambda, Sigma, and Xi). The interactions are basically studied from the meson-exchange point of view, in the spirit of the Yukawa-approach to the nuclear force problem [H. Yukawa, ``On the interaction of Elementary Particles I'', Proceedings of the Physico-Mathematical Society of Japan 17 (1935), 48], using generalized soft-core Yukawa-functions. These interactions are supplemented with (i) multiple-gluon-exchange, and (ii) structural effects due to the quark-core of the baryons. We present in some detail the most recent extended-soft-core model, henceforth referred to as ESC08, which is the most complete, sophisticated, and successful interaction-model. Furthermore, we discuss briefly its predecessor the ESC04-model [Th. A. Rijken and Y. Yamamoto, Phys. Rev. C 73 (2006), 044007; Th. A. Rijken and Y. Yamamoto, Ph ys. Rev. C 73 (2006), 044008; Th. A. Rijken and Y. Yamamoto, nucl-th/0608074]. For the soft-core one-boson-exchange (OBE) models we refer to the literature [Th. A. Rijken, in Proceedings of the International Conference on Few-Body Problems in Nuclear and Particle Physics, Quebec, 1974, ed. R. J. Slobodrian, B. Cuec and R. Ramavataram (Presses Universitè Laval, Quebec, 1975), p. 136; Th. A. Rijken, Ph. D. thesis, University of Nijmegen, 1975; M. M. Nagels, Th. A. Rijken and J. J. de Swart, Phys. Rev. D 17 (1978), 768; P. M. M. Maessen, Th. A. Rijken and J. J. de Swart, Phys. Rev. C 40 (1989), 2226; Th. A. Rijken, V. G. J. Stoks and Y. Yamamoto, Phys. Rev. C 59 (1999), 21; V. G. J. Stoks and Th. A. Rijken, Phys. Rev. C 59 (1999), 3009]. All ingredients of these latter models are also part of ESC08, and so a description of ESC08 comprises all models so far in principle. The extended-soft-core (ESC) interactions consist of local- and non-local-potentials due to (i) one-boson-exchanges (OBE), which are the members of nonets of
Holographic heavy ion collisions with baryon charge
Casalderrey-Solana, Jorge; van der Schee, Wilke; Triana, Miquel
2016-01-01
We numerically simulate collisions of charged shockwaves in Einstein-Maxwell theory in anti-de Sitter space as a toy model of heavy ion collisions with non-zero baryon charge. The stress tensor and the baryon current become well described by charged hydrodynamics at roughly the same time. The effect of the charge density on generic observables is typically no larger than 15\\%. %The rapidity profile of the charge is wider than the profile of the local energy density. We find significant stopping of the baryon charge and compare our results with those in heavy ion collision experiments.
More about the light baryon spectrum
Eichmann, Gernot
2016-01-01
We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with 'anomalous' states, and we propose a method to eliminate them from the spectrum.
More About the Light Baryon Spectrum
Eichmann, Gernot
2017-03-01
We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with `anomalous' states, and we propose a method to eliminate them from the spectrum.
The baryon spectrum and the hypercentral Constituent Quark Model
Giannini, M M
2015-01-01
The description of the baryon spectrum is performed using the hypercentral Consituent Quark Model (hCQM), mainly in comparison with the harmonic oscillator (h.o.). Recentlly many new states, at various levels of confidence have been observed, leading to a softening of the missing resonance problem in the case of positive parity states. However, the number of negative states is higher that predicted by the commonly used h.o. scheme and therefore one is forced to take into account also the higher energy shells, which contain an overall number of states much greater than the observed one. It is shown that, thanks to the peculiar level scheme of the hCQM, the recently observed negative parity states can be considered as belonging to the lower shells, keeping the missing resonance problem within more acceptable limits.
Pire, Bernard; Szymanowski, Lech
2010-01-01
We construct a spectral representation for the transition distribution amplitudes (TDAs), i.e. matrix elements of three quark correlators which arise e.g. in the description of baryon to meson and baryon to photon transitions within the factorization approach to hard exclusive reactions. We generalize for these quantities the notion of double distributions introduced in the context of generalized parton distributions. We propose the generalization of A.Radyushkin's factorized Ansatz for the case of baryon to meson and baryon to photon TDAs. Our construction opens the way to modeling of baryon to meson and baryon to photon TDAs in their complete domain of definition and quantitative estimates of cross-sections for various hard exclusive reactions.
Masses and magnetic moments of ground-state baryons in covariant baryon chiral perturbation theory
Geng, L S; Alvarez-Ruso, L; Vicente-Vacas, M J
2012-01-01
We report on some recent developments in our understanding of the light-quark mass dependence and the SU(3) flavor symmetry breaking corrections to the magnetic moments of the ground-state baryons in a covariant formulation of baryon chiral perturbation theory, the so-called EOMS formulation. We show that this covariant ChPT exhibits some promising features compared to its heavy-baryon and infrared counterparts.
Suppression of Baryon Diffusion and Transport in a Baryon Rich Strongly Coupled Quark-Gluon Plasma.
Rougemont, Romulo; Noronha, Jorge; Noronha-Hostler, Jacquelyn
2015-11-13
Five dimensional black hole solutions that describe the QCD crossover transition seen in (2+1)-flavor lattice QCD calculations at zero and nonzero baryon densities are used to obtain predictions for the baryon susceptibility, baryon conductivity, baryon diffusion constant, and thermal conductivity of the strongly coupled quark-gluon plasma in the range of temperatures 130 MeV≤T≤300 MeV and baryon chemical potentials 0≤μ(B)≤400 MeV. Diffusive transport is predicted to be suppressed in this region of the QCD phase diagram, which is consistent with the existence of a critical end point at larger baryon densities. We also calculate the fourth-order baryon susceptibility at zero baryon chemical potential and find quantitative agreement with recent lattice results. The baryon transport coefficients computed in this Letter can be readily implemented in state-of-the-art hydrodynamic codes used to investigate the dense QGP currently produced at RHIC's low energy beam scan.
New scenarios for hard-core interactions in a hadron resonance gas
Satarov, L M; Alba, P; Gorenstein, M I; Stoecker, H
2016-01-01
The equation of state of a baryon-symmetric hadronic matter with hard-sphere interactions is studied. It is assumed that mesons are point-like, but baryons and antibaryons have the same hard-core radius rB. Three possibilities are considered: 1) the baryon-baryon and antibaryon-baryon interactions are the same; 2) baryons do not interact with antibaryons; 3) the baryon-antibaryon and meson-(anti)baryon interactions are negligible. By choosing the parameter rB=0.3-0.6 fm, we calculate the nucleon to pion ratio as a function of temperature and perform the fit of hadron yields measured in central Pb+Pb collisions at the bombarding energy Ecm=2.76 TeV per nucleon pair. New nontrivial effects in the interacting hadron resonance gas at temperatures 150-200 MeV are found.
Baryon asymmetry from primordial black holes
Hamada, Yuta
2016-01-01
We propose a new scenario of the baryogenesis from primordial black holes (PBH). Assuming presence of a microscopic baryon (or lepton) number violation and a CP violating operator such as $\\partial_\\alpha F(\\mathcal{R_{....}} ) J^\\alpha$ where $F(\\mathcal{R_{....}})$ is a scalar function of the Riemann tensor, time evolution of an evaporating black hole generates baryonic (leptonic) chemical potential at the horizon; consequently PBH enumerates asymmetric Hawking radiation between baryons (leptons) and anti-baryons (leptons). Though the operator is higher dimensional and largely suppressed by a high mass scale $M_*$, we show that sufficient amount of asymmetry can be generated for wide range of parameters of the PBH mass $M_{\\rm PBH}$, its abundance $\\Omega_{\\rm PBH}$, and the scale $M_*$.
Baryonic torii: Toroidal baryons in a generalized Skyrme model
Gudnason, Sven Bjarke; Nitta, Muneto
2015-02-01
We study a Skyrme-type model with a potential term motivated by Bose-Einstein condensates (BECs), which we call the BEC Skyrme model. We consider two flavors of the model: the first is the Skyrme model, and the second has a sixth-order derivative term instead of the Skyrme term, both with the added BEC-motivated potential. The model contains toroidally shaped Skyrmions, and they are characterized by two integers P and Q , representing the winding numbers of two complex scalar fields along the toroidal and poloidal cycles of the torus, respectively. The baryon number is B =P Q . We find stable Skyrmion solutions for P =1 ,2 ,3 ,4 ,5 with Q =1 , while for P =6 and Q =1 , it is only metastable. We further find that configurations with higher Q >1 are all unstable and split into Q configurations with Q =1 . Finally we discover a phase transition, possibly of first order, in the mass parameter of the potential under study.
Heavy Flavor Baryons at the Tevatron
Energy Technology Data Exchange (ETDEWEB)
Kuhr, Thomas
2011-09-01
The Tevatron experiments CDF and D0 have filled many empty spots in the spectrum of heavy baryons over the last few years. The most recent results are described in this article: The first direct observation of the {Xi}{sub b}{sup 0}, improved measurements of {Sigma}{sub b} properties, a new measurement of the {Lambda}{sub b} {yields} J/{psi}{Lambda} branching ratio, and a high-statistics study of charm baryons.
The baryon content of the Cosmic Web
Eckert, Dominique; Jauzac, Mathilde; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Céline
2015-01-01
Big-Bang nucleosynthesis indicates that baryons account for 5% of the Universe’s total energy content[1]. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two[2,3]. Cosmological simulations indicate that the missing baryons have not yet condensed into virialised halos, but reside throughout the filaments of the cosmic web: a low-density plasma at temperature 105–107 K known as the warm-hot intergalactic medium (WHIM)[3,4,5,6]. There have been previous claims of the detection of warm baryons along the line of sight to distant blazars[7,8,9,10] and hot gas between interacting clusters[11,12,13,14]. These observations were however unable to trace the large-scale filamentary structure, or to estimate the total amount of warm baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of ten-million-degree gas associated with the galaxy cluster Abell 2744. Previous observations of this cluster[15] were unable to resolve and remove coincidental X-ray point sources. After subtracting these, we reveal hot gas structures that are coherent over 8 Mpc scales. The filaments coincide with over-densities of galaxies and dark matter, with 5-10% of their mass in baryonic gas. This gas has been heated up by the cluster's gravitational pull and is now feeding its core. PMID:26632589
Spin-flavor composition of excited baryons
Fernando, Ishara; Goity, Jose
2015-10-01
The excited baryon masses are analyzed in the framework of the 1 /Nc expansion using the available physical masses and also the masses obtained in lattice QCD for different quark masses. The baryon states are organized into irreducible representations of SU (6) × O (3) , where the [ 56 ,lP =0+ ] ground state and excited baryons, and the [ 56 ,2+ ] and [ 70 ,1- ] excited states are analyzed. The analyses are carried out to O 1 /Nc and first order in the quark masses. The issue of state identifications is discussed. Numerous parameter independent mass relations result at those orders, among them the well known Gell-Mann-Okubo and Equal Spacing relations, as well as additional relations involving baryons with different spins. It is observed that such relations are satisfied at the expected level of precision. Predictions for physically unknown states for each multiplet are obtained. From the quark-mass dependence of the coefficients in the baryon mass formulas an increasingly simpler picture of the spin-flavor composition of the baryons is observed with increasing pion mass (equivalently, increasing mu , d masses), as measured by the number of significant mass operators. This work was supported in part by DOE Contract No. DE-AC05-06OR23177 under which JSA operates the Thomas Jefferson National Accelerator Facility (J. L. G.), and by the NSF (USA) through Grant PHY-0855789 and PHY-1307413 (I. P. F and J. L. G).
Search for doubly charmed baryons and study of charmed strange baryons at Belle
Energy Technology Data Exchange (ETDEWEB)
Kato, Y.; Iijima, T.; Adachi, I.; Aihara, H.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Bala, A.; Ban, Y.; Bhardwaj, V.; Bhuyan, B.; Bobrov, A.; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, Y.; Cinabro, D.; Dalseno, J.; Danilov, M.; Doležal, Z.; Drásal, Z.; Drutskoy, A.; Dutta, D.; Dutta, K.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Gaur, V.; Gabyshev, N.; Ganguly, S.; Garmash, A.; Gillard, R.; Goh, Y. M.; Golob, B.; Haba, J.; Hayasaka, K.; Hayashii, H.; He, X. H.; Horii, Y.; Hoshi, Y.; Hou, W. -S.; Hsiung, Y. B.; Inami, K.; Ishikawa, A.; Iwasaki, Y.; Iwashita, T.; Jaegle, I.; Julius, T.; Kang, J. H.; Kato, E.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, J. H.; Kim, M. J.; Kim, Y. J.; Klucar, J.; Ko, B. R.; Kodyš, P.; Korpar, S.; Krokovny, P.; Kuhr, T.; Kuzmin, A.; Kwon, Y. -J.; Lee, S. -H.; Li, J.; Li, Y.; Li Gioi, L.; Libby, J.; Liu, Y.; Liventsev, D.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Moll, A.; Muramatsu, N.; Mussa, R.; Nagasaka, Y.; Nakano, E.; Nakao, M.; Nakazawa, H.; Nayak, M.; Nedelkovska, E.; Ng, C.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Nitoh, O.; Ogawa, S.; Okuno, S.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H.; Park, H. K.; Pedlar, T. K.; Peng, T.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Ritter, M.; Röhrken, M.; Rostomyan, A.; Sahoo, H.; Saito, T.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Semmler, D.; Senyo, K.; Seon, O.; Shapkin, M.; Shen, C. P.; Shibata, T. -A.; Shiu, J. -G.; Shwartz, B.; Sibidanov, A.; Sohn, Y. -S.; Sokolov, A.; Solovieva, E.; Stanič, S.; Starič, M.; Steder, M.; Sumihama, M.; Sumiyoshi, T.; Tamponi, U.; Tanida, K.; Tatishvili, G.; Teramoto, Y.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Vinokurova, A.; Vorobyev, V.; Wagner, M. N.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yamashita, Y.; Yashchenko, S.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.
2014-03-17
We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider.
Study of B-Meson Decays to Final States with a Single Charm Baryon
Energy Technology Data Exchange (ETDEWEB)
Majewski, Stephanie A. [Stanford Univ., CA (United States)
2007-08-01
A study of B-meson decays to final states with a single charm baryon is presented based on data recorded by the BABAR detector at the Stanford Linear Accelerator Center. Although the B meson is the lightest bottom-flavored meson, it is heavy enough to decay to a baryon made of three quarks and an antibaryon made of three antiquarks. By studying the baryonic weak decays of the B meson, we can investigate baryon production mechanisms in heavy meson decays. In particular, we measure the rates of the decays B^{-} → Λ^{+}_{c}$\\bar{p}$π^{-} and $\\bar{B}$^{0} → Λ^{+}_{c}$\\bar{p}$. Comparing these rates, we confirm an observed trend in baryonic B decays that the decay with the lower energy release, B^{-} → Λ^{+}_{c}$\\bar{p}$π^{-}, is favored over $\\bar{B}$^{0} → Λ^{+}_{c}$\\bar{p}$. The dynamics of the baryon-antibaryon (Λ^{+}_{c}$\\bar{p}$) system in the three-body decay also provide insight into baryon-antibaryon production mechanisms. The B^{-} → Λ^{+}_{c}$\\bar{p}$π^{-} system is a laboratory for searches for excited #c baryon states; we observe the resonant decays B^{-} → Σc(2455) ^{0}$\\bar{p}$ and B^{-} → Σ_{c}(2800) ^{0}$\\bar{p}$. This is the first observation of the decay B^{-} → Σ_{c}(2800) ^{0}$\\bar{p}$; however, the mass of the observed #c(2800)0 state is inconsistent with previous measurements. Finally, we examine the angular distribution of the B^{-} → Σ_{c}(2455) ^{0}$\\bar{p}$ decays and measure the spin of the B^{-} → Σ_{c}(2455) ^{0}$\\bar{p}$ baryon to be J = 1/2, as predicted by the quark model.
Baryon-baryon bound states in a (2+1)-dimensional lattice QCD model
Faria da Veiga, Paulo A.; O'Carroll, Michael; Schor, Ricardo
2003-08-01
We consider bound states of two baryons (antibaryons) in lattice QCD in a Euclidean formulation. For simplicity, we analyze an SU(3) theory with a single flavor in 2+1 dimensions and two-dimensional Dirac matrices. For a small hopping parameter 0<κ≪1 and large glueball mass, we recently showed the existence of a (anti)baryonlike particle, with an asymptotic mass of the order of -3 ln κ and with an isolated dispersion curve, i.e., an upper gap property persisting up to near the meson-baryon threshold, which is of order -5 ln κ. Here, we show that there is no baryon-baryon (or antibaryon-antibaryon) bound state solution to the Bethe-Salpeter equation up to the two-baryon threshold, which is approximately -6 ln κ.
Penta-quark baryon in anisotropic lattice QCD
Ishii, N; Iida, H; Oka, M; Okiharu, F; Suganuma, H
2005-01-01
The penta-quark(5Q) baryon is studied in anisotropic quenched lattice QCD with renormalized anisotropy a_s/a_t=4 for a high-precision mass measurement. The standard Wilson action at beta=5.75 and the O(a) improved Wilson quark action with kappa=0.1210(0.0010)0.1240 are employed on a 12^3 \\times 96 lattice. Contribution of excited states is suppressed by using a smeared source. We investigate both the positive- and negative-parity 5Q baryons with I=0 and spin J=1/2 using a non-NK-type interpolating field. After chiral extrapolation, the lowest positive-parity state is found to have a mass, m_{Theta}=2.25 GeV, which is much heavier than the experimentally observed Theta^+(1540). The lowest negative-parity 5Q appears at m_{Theta}=1.75 GeV, which is near the s-wave NK threshold. To distinguish spatially-localized 5Q resonances from NK scattering states, we propose a new general method imposing a ``Hybrid Boundary Condition (HBC)'', where the NK threshold is artificially raised without affecting compact five-quark...
Heavy baryon spectroscopy from the lattice
Energy Technology Data Exchange (ETDEWEB)
Bowler, K.C.; Kenway, R.D.; Oliveira, O.; Richards, D.G.; Ueberholz, P. [Department of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ (Scotland); Lellouch, L.; Nieves, J.; Sachrajda, C.T.; Stella, N.; Wittig, H. [Physics Department, The University, Southampton SO17 1BJ (United Kingdom)
1996-09-01
The results of an exploratory lattice study of heavy baryon spectroscopy are presented. We have computed the full spectrum of the eight baryons containing a single heavy quark, on a 24{sup 3}{times}48 lattice at {beta}=6.2, using an {ital O}({ital a})-improved fermion action. We discuss the lattice baryon operators and give a method for isolating the contributions of the spin doublets ({Sigma},{Sigma}{sup {asterisk}}), ({Xi}{sup {prime}},{Xi}{sup {asterisk}}), and ({Omega},{Omega}{sup {asterisk}}) to the correlation function of the relevant operator. We compare our results with the available experimental data and find good agreement in both the charm and the {ital b}-quark sectors, despite the long extrapolation in the heavy quark mass needed in the latter case. We also predict the masses of several undiscovered baryons. We compute the {Lambda}-pseudoscalar meson and {Sigma}-{Lambda} mass splittings. Our results, which have errors in the range 10{endash}30{percent}, are in good agreement with the experimental numbers. For the {Sigma}{sup {asterisk}}-{Sigma} mass splitting, we find results considerably smaller than the experimental values for both the charm and the {ital b}-flavored baryons, although in the latter case the experimental results are still preliminary. This is also the case for the lattice results for the hyperfine splitting for the heavy mesons. {copyright} {ital 1996 The American Physical Society.}
Light-Quark Baryon Spectroscopy within ANL-Osaka Dynamical Coupled-Channels Approach
Kamano, Hiroyuki
2016-10-01
Recent results on the study of light-quark baryons with the ANL-Osaka dynamical coupled-channels (DCC) approach are presented, which contain the N^* and Δ ^* spectroscopy via the analysis of π N and γ N reactions and the Λ ^* and Σ ^* spectroscopy via the analysis of K^- p reactions. A recent application of our DCC approach to neutrino-nucleon reactions in the resonance region is also presented.
Papastergis, Emmanouil; Huang, Shan; Giovanelli, Riccardo; Haynes, Martha P
2012-01-01
We use both an HI-selected and an optically-selected galaxy sample to directly measure the abundance of galaxies as a function of their "baryonic" mass (stars + atomic gas). Stellar masses are calculated based on optical data from the Sloan Digital Sky Survey (SDSS) and atomic gas masses are calculated using atomic hydrogen (HI) emission line data from the Arecibo Legacy Fast ALFA (ALFALFA) survey. By using the technique of abundance matching, we combine the measured baryonic function (BMF) of galaxies with the dark matter halo mass function in a LCDM universe, in order to determine the galactic baryon fraction as a function of host halo mass. We find that the baryon fraction of low-mass halos is much smaller than the cosmic value, even when atomic gas is taken into account. We find that the galactic baryon deficit increases monotonically with decreasing halo mass, in contrast with previous studies which suggested an approximately constant baryon fraction at the low-mass end. We argue that the observed baryon...
Heavy Baryons in a Quark Model
Energy Technology Data Exchange (ETDEWEB)
Winston Roberts; Muslema Pervin
2007-11-14
A quark model is applied to the spectrum of baryons containing heavy quarks. The model gives masses for the known heavy baryons that are in agreement with experiment, but for the doubly-charmed baryon $\\Xi_{cc}$, the model prediction is too heavy. Mixing between the $\\Xi_Q$ and $\\Xi_Q^\\prime$ states is examined and is found to be small for the lowest lying states. In contrast with this, mixing between the $\\Xi_{bc}$ and $\\Xi_{bc}^\\prime$ states is found to be large, and the implication of this mixing for properties of these states is briefly discussed. We also examine heavy-quark spin-symmetry multiplets, and find that many states in the model can be placed in such multiplets.
Compressed Baryonic Matter: from Nuclei to Pulsars
Xu, Renxin
2013-01-01
Our world is wonderful because of the negligible baryonic part although unknown dark matter and dark energy dominate the Universe. Those nuclei in the daily life are forbidden to fuse by compression due to the Coulomb repulse, nevertheless, it is usually unexpected in extraterrestrial extreme-environments: the gravity in a core of massive evolved star is so strong that all the other forces (including the Coulomb one) could be neglected. Compressed baryonic matter is then produced after supernova, manifesting itself as pulsar-like stars observed. The study of this compressed baryonic matter can not only be meaningful in fundamental physics (e.g., the elementary color interaction at low-energy scale, testing gravity theories, detecting nano-Hertz background gravitational waves), but has also profound implications in engineering applications (including time standard and navigation), and additionally, is focused by Chinese advanced telescopes, either terrestrial or in space. Historically, in 1930s, L. Landau spec...
Spectroscopy of charmed baryons from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Padmanath, M. [Univ. of Graz (Austria). Inst. of Physics; Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mathur, Nilmani [Tata Institute of Fundamental Research, Bombay (India); Peardon, Michael [Trinity College, Dublin (Ireland)
2015-01-01
We present the ground and excited state spectra of singly, doubly and triply charmed baryons by using dynamical lattice QCD. A large set of baryonic operators that respect the symmetries of the lattice and are obtained after subduction from their continuum analogues are utilized. Using novel computational techniques correlation functions of these operators are generated and the variational method is exploited to extract excited states. The lattice spectra that we obtain have baryonic states with well-defined total spins up to 7/2 and the low lying states remarkably resemble the expectations of quantum numbers from SU(6) x O(3) symmetry. Various energy splittings between the extracted states, including splittings due to hyperfine as well as spin-orbit coupling, are considered and those are also compared against similar energy splittings at other quark masses.
Dark Matter and the Baryon Asymmetry
Farrar, G R; Farrar, Glennys R.; Zaharijas, Gabrijela
2006-01-01
We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\mathcal{O}$(10%) or more, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$. Two concrete examples are given, one of which can be excluded on observational grounds.
Production and decay of charmed baryons
Hosaka, Atsushi; Hiyama, Emiko; Kim, SangHo; Kim, Hyun-Chul; Nagahiro, Hideko; Noumi, Hiroyuki; Oka, Makoto; Shirotori, Kotaro; Yoshida, Tetsuya; Yasui, Shigehiro
2016-10-01
In this paper, we discuss reactions involving charmed baryons to explore their unique features. A well known phenomenon, the separation of the two internal motions of the ρ and λ types of a three-quark system is revisited. First we discuss the mass spectrum of low lying excitations as function of the heavy quark mass, smoothly connecting the SU (3) and heavy quark limits. The properties of these modes can be tested in the production and decay reactions of the baryons. For production, we consider a one step process which excites dominantly λ modes. We find abundant production rates for some of the excited states. For decay, we study a pion emission process which provides a clean tool to test the structure of heavy quark systems due to the well controlled low energy dynamics of pions and quarks. Both production and decay of charmed baryons are issues for future experiments at J-PARC.
Baryon number and charge fluctuations from lattice QCD
Schmidt, Christian
2012-01-01
We calculate electric and baryonic charge fluctuations on the lattice. Results have been obtained with the highly improved staggered quark action (HISQ) and almost physical quark masses on lattices with spacial extent of $N_\\tau=6,8,12$. Higher order cumulants of the net-charge distributions are increasingly dominated by a universal scaling behavior, which is arising due to a critical point of QCD in the chiral limit. Considering cumulants up to the sixth order, we observe that they generically behave as expected from universal scaling laws, which is quite different from the cumulants calculated within the hadron resonance gas model. Taking ratios of these cumulants, we obtain volume independent results that can be compared to the experimental measurements. Such a comparison will unambiguously relate the QCD transition temperature that has been determined on the lattice with the freeze out temperature of heavy ion collision at LHC and RHIC.
Exciting Baryons: now and in the future
Pennington, M R
2011-01-01
This is the final talk of NSTAR2011 conference. It is not a summary talk, but rather a looking forward to what still needs to be done in excited baryon physics. In particular, we need to hone our tools connecting experimental inputs with QCD. At present we rely on models that often have doubtful connections with the underlying theory, and this needs to be dramatically improved, if we are to reach definitive conclusions about the relevant degrees of freedom of excited baryons. Conclusions that we want to have by NSTAR2021.
Decuplet baryons in a hot medium
Energy Technology Data Exchange (ETDEWEB)
Azizi, K.; Bozkir, G. [Dogus Univ., Istanbul (Turkey). Dept. of Physics
2016-10-15
The thermal properties of the light decuplet baryons are investigated in the framework of the thermal QCD sum rules. In particular, the behavior of the mass and residue of the Δ, Σ*, Ξ*, and Ω baryons with respect to temperature are analyzed taking into account the additional operators appearing in the Wilson expansion at finite temperature. It is found that the mass and residue of these particles remain overall unaffected up to T ≅ 150 MeV but, beyond this point, they start to diminish considerably. (orig.)
Constructing Hybrid Baryons with Flux Tubes
Capstick, Simon; Capstick, Simon; Page, Philip R.
1999-01-01
Hybrid baryon states are described in quark potential models as having explicit excitation of the gluon degrees of freedom. Such states are described in a model motivated by the strong coupling limit of Hamiltonian lattice gauge theory, where three flux tubes meeting at a junction play the role of the glue. The adiabatic approximation for the quark motion is used, and the flux tubes and junction are modeled by beads which are attracted to each other and the quarks by a linear potential, and vibrate in various string modes. Quantum numbers and estimates of the energies of the lightest hybrid baryons are provided.
Heavy flavor baryons in hypercentral model
Indian Academy of Sciences (India)
Bhavin Patel; Ajay Kumar Rai; P C Vinodkumar
2008-05-01
Heavy flavor baryons containing single and double charm (beauty) quarks with light flavor combinations are studied using the hypercentral description of the three-body problem. The confinement potential is assumed as hypercentral Coulomb plus power potential with power index . The ground state masses of the heavy flavor, $J^{P} = \\dfrac{1}{2}^{+}$ and $\\dfrac{3}{2}^{+}$ baryons are computed for different power indices, starting from 0.5 to 2.0. The predicted masses are found to attain a saturated value in each case of quark combinations beyond the power index = 1.0.
Heavy Baryon Transitions in a Relativistic Three-Quark Model
Ivanov, M A; Kroll, P; Lyubovitskij, V E
1997-01-01
Exclusive semileptonic decays of bottom and charm baryons are considered within a relativistic three-quark model with a Gaussian shape for the baryon-three-quark vertex and standard quark propagators. We calculate the baryonic Isgur-Wise functions, decay rates and asymmetry parameters.
Algebraic Treatment of Collective Excitations in Baryon Spectroscopy
Bijker, R
1993-01-01
We present an algebraic U(7) model for baryons which encompasses both single-particle and collective forms of quark dynamics. The mass operator by construction preserves the permutation symmetry between identical quarks. The underlying geometric structure of baryons is discussed in terms of a rigid rotating and vibrating oblate top shape. The model is applied to the mass spectrum of nonstrange baryons.
Strangeness -2 and -3 Baryons in a Constituent Quark Model
Energy Technology Data Exchange (ETDEWEB)
Muslema Pervin; Winston Roberts
2007-09-19
We apply a quark model developed in earlier work to the spectrum of baryons with strangeness -2 and -3. The model describes a number of well-established baryons successfully, and application to cascade baryons allows the quantum numbers of some known states to be deduced.
Baryon Resonances in the STAR Experiment at RHIC
Directory of Open Access Journals (Sweden)
Witt Richard
2015-01-01
Full Text Available We present measurements of mass, width, and yields of the Δ(1232++, Σ(1385 and Λ(1520 from p + p, d+Au, and Au+Au collisions at √sNN = 200 GeV in the STAR experiment at Brookhaven National Laboratory’s Relativistic Heavy-Ion Collider (RHIC. These measurements are discussed in the context of re-scattering and regeneration. We also discuss preliminary measurements of the Ξ(1530 and possibilities for upcoming measurements based on recently collected data.
Dynamically-generated baryon resonances with heavy flavor
Romanets, Olena
2014-01-01
De studie van zware hadronen is een belangrijk onderwerp in de deeltjesfysica. In tegenstelling tot deeltjes die opgebouwd zijn uit lichte quarks,zijn toestanden met zware quarks (bijvoorbeeld charm of bottom quarks) moeilijk te beschrijven, omdat er geen goed model is. De ontwikkeling van nieuwe ex
Electroweak interactions and dark baryons in the sextet BSM model with a composite Higgs particle
Fodor, Zoltan; Holland, Kieran; Kuti, Julius; Mondal, Santanu; Nogradi, Daniel; Wong, Chik Him
2016-07-01
The electroweak interactions of a strongly coupled gauge theory are discussed with an outlook beyond the Standard Model (BSM) under global and gauge anomaly constraints. The theory is built on a minimal massless fermion doublet of the SU(2) BSM flavor group (bsm-flavor) with a confining gauge force at the TeV scale in the two-index symmetric (sextet) representation of the BSM SU(3) color gauge group (bsm-color). The intriguing possibility of near-conformal sextet gauge dynamics could lead to the minimal realization of the composite Higgs mechanism with a light 0++ scalar, far separated from strongly coupled resonances of the confining gauge force in the 2-3 TeV range, distinct from Higgsless technicolor. In previous publications we have presented results for the meson spectrum of the theory, including the light composite scalar, which is perhaps the emergent Higgs impostor. Here we discuss the critically important role of the baryon spectrum in the sextet model investigating its compatibility with what we know about thermal evolution of the early Universe including its galactic and terrestrial relics. For an important application, we report the first numerical results on the baryon spectrum of this theory from nonperturbative lattice simulations with baryon correlators in the staggered fermion implementation of the strongly coupled gauge sector. The quantum numbers of composite baryons and their spectroscopy from lattice simulations are required inputs for exploring dark matter contributions of the sextet BSM model, as outlined for future work.
Observation of an Exotic Baryon with S=+1 in Photoproduction from the Proton
Kubarovski, V; Weygand, D P; Stoler, P; Battaglieri, M; De Vita, R; Adams, G; Ji Li; Nozar, M; Salgado, C; Ambrozewicz, P; Anciant, E; Anghinolfi, M; Asavapibhop, B; Audit, G; Auger, T; Avakian, H; Bagdasaryan, H; Ball, J P; Barrow, S; Beard, K; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Bianchi, N; Biselli, A S; Boiarinov, S; Bouchigny, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Burkert, V D; Butuceanu, C; Calarco, J R; Carman, D S; Carnahan, B; Cetina, C; Chen, S; Ciciani, L; Cole, P L; Connelly, J; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J P; De Sanctis, E; Degtyarenko, P V; Denizli, H; Dennis, L; Dharmawardane, K V; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Empl, A; Eugenio, P; Farhi, L; Fatemi, R; Feuerbach, R J; Ficenec, J; Forest, T A; Frolov, V; Funsten, H; Gaff, S J; Garçon, M; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girard, P; Gothe, R W; Gordon, C I O; Griffioen, K; Guidal, M; Guillo, M R; Gyurjyan, V; Hadjidakis, C; Hakobyan, R S; Hancock, D; Hardie, J; Heddle, D; Heimberg, P; Hersman, F W; Hicks, K; Holtrop, M; Hu, J; Hyde-Wright, C E; Ilieva, Y; Ito, M M; Jenkins, D; Joo, K; Jüngst, H G; Kelley, J H; Khandaker, M; Kim, K Y; Kim, K; Kim, W; Klein, F J; Klimenko, A V; Klusman, M; Kossov, M; Kramer, L H; Kuhn, S E; Kühn, J; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Longhi, A; Lukashin, K; Major, R W; Manak, J J; Marchand, C; McAleer, S; McNabb, J W C; Mecking, B A; Mehrabyan, S S; Melone, J J; Mestayer, M D; Meyer, C A; Mikhailov, K; Minehart, R C; Mirazita, M; Miskimen, R; Mokeev, V; Morand, L; Morrow, S A; Mozer, M U; Muccifora, V; Müller, J; Mutchler, G S; Napolitano, J; Nasseripour, R; Nelson, S O; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niyazov, R A; O'Brien, J T; O'Rielly, G V; Opper, A K; Osipenko, M; Park, K; Pasyuk, E A; Peterson, G; Philips, S A; Pivnyuk, N; Pocanic, D; Pogorelko, O I; Polli, E; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rossi, P; Rowntree, D; Rubin, P D; Sabatie, F; Sabourov, K; Santoro, J P; Sapunenko, V; Sargsyan, M; Schumacher, R A; Serov, V S; Shafi, A; Sharabyan, Yu G; Shaw, J; Simionatto, S; Skabelin, A V; Smith, E S; Smith, T; Smith, L C; Sober, D I; Spraker, M; Stavinsky, A V; Stepanyan, S; Strakovsky, I I; Strauch, S; Taiuti, M; Taylor, S; Tedeschi, D J; Thoma, U; Thompson, R; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Wang, K; Weinstein, L B; Weisberg, A; Whisnant, C S; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J
2004-01-01
The reaction $\\gamma p \\to \\pi^+K^-K^+n$ was studied at Jefferson Lab using a tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state with strangeness S=+1 and mass $M=1555\\pm 10$ MeV/c$^2$ was observed in the $nK^+$ invariant mass spectrum. The peak's width is consistent with the CLAS resolution (FWHM=26 MeV/c$^2$), and its statistical significance is 7.8 $\\pm$ 1.0 ~$\\sigma$. A baryon with positive strangeness has exotic structure and cannot be described in the framework of the naive constituent quark model. The state is consistent with the mass predicted by a chiral soliton model \\cite{Diakonov} for 5-quark baryon states. In addition, the $pK^+$ invariant mass distribution was analyzed in the reaction $\\gamma p\\to K^-K^+p$ with high statistics in search of doubly-charged exotic baryon states. No resonance structures were found in this spectrum.
Energy Technology Data Exchange (ETDEWEB)
Knippschild, Bastian
2012-03-05
Quantum Chromodynamics (QCD) is the theory of strong interactions, one of the four fundamental forces in our Universe. It describes the interaction of gluons and quarks which build up hadrons like protons and neutrons. Most of the visible matter in our universe is made of protons and neutrons. Hence, we are interested in their fundamental properties like their masses, their distribution of charge and their shape. The only known theoretical, non-perturbative and ab initio method to investigate hadron properties at low energies is lattice Quantum Chromodynamics (lattice QCD). However, up-to-date simulations (especially for baryonic quantities) do not achieve the accuracy of experiments. In fact, current simulations do not even reproduce the experimental values for the form factors. The question arises wether these deviations can be explained by systematic effects in lattice QCD simulations. This thesis is about the computation of nucleon form factors and other hadronic quantities from lattice QCD. So called Wilson fermions are used and the u- and d-quarks are treated fully dynamically. The simulations were performed using gauge ensembles with a range of lattice spacings, volumes and pion masses. First of all, the lattice spacing was set to be able to make contact between the lattice results and their experimental complement and to be able to perform a continuum extrapolation. The light quark mass has been computed and found to be m{sub ud}{sup MS}(2 GeV)=3.03(17)(38) MeV. This value is in good agreement with values from experiments and other lattice determinations. Electro-magnetic and axial form factors of the nucleon have been calculated. From these form factors the nucleon radii and the coupling constants were computed. The different ensembles enabled us to investigate systematically the dependence of these quantities on the volume, the lattice spacing and the pion mass. Finally we perform a continuum extrapolation and chiral extrapolations to the physical point
Multiinstanton ladders in baryon number violating processes
Lazarides, G
1995-01-01
We estimate the contribution of a class of multiinstanton ladder graphs to baryon and lepton number violating processes in the standard model. We find that this contribution is negligible and does not alter the high energy behavior of the leading semiclassical approximation.
Beauty baryon decays: a theoretical overview
Wang, Yu-Ming
2014-11-01
I overview the theoretical status and recent progress on the calculations of beauty baryon decays focusing on the QCD aspects of the exclusive semi-leptonic Λb → plμ decay at large recoil and theoretical challenges of radiative and electro-weak penguin decays Λb → Λγ,Λl+l-.
Baryon Ratios in Quark-Gluon Plasma
Institute of Scientific and Technical Information of China (English)
MA Zhong-Biao; MIAO Hong; GAO Chong-Shou
2003-01-01
A way to calculate ratios of baryon produced from quark gluon plasma in relativistic heavyion collisionsis presented. It is assumed that at the beginning of the hadronization there are diquarks and anti-diquarks in the quarkmatter. The number of three-quark states is distributed between the corresponding multiplets, and hadronic decays aretaken into account. The results are shown at last.
Baryons in the unquenched quark model
Bijker, R; Lopez-Ruiz, M A; Santopinto, E
2016-01-01
In this contribution, we present the unquenched quark model as an extension of the constituent quark model that includes the effects of sea quarks via a $^{3}P_{0}$ quark-antiquark pair-creation mechanism. Particular attention is paid to the spin and flavor content of the proton, magnetic moments and $\\beta$ decays of octet baryons.
Light element synthesis in baryon isocurvature models
Kumar, D L P
2006-01-01
The prejudice against baryon isocurvature models is primarily because of their inconsistency with early universe light element nucleosynthesis results. We propose that incipient low metallicity (Pop II) star forming regions can be expected to have environments conducive to Deuterium production by spallation, up to levels observed in the universe.
Baryons in a chiral constituent quark model
Glozman, L Ya
1998-01-01
In the low-energy regime light and strange baryons should be considered as systems of constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons as well as by vector and scalar mesons. The flavor-spin structure and sign of the short-range part of the spin-spin force reduces the $SU(6)_{FS}$ symmetry down to $SU(3)_F \\times SU(2)_S$, induces hyperfine splittings and provides correct ordering of the lowest states with positive and negative parity. There is a cancellation of the tensor force from pseudoscalar- and vector-exchanges in baryons. The spin-orbit interactions from $\\rho$-like and $\\omega$-like exchanges also cancel each other in baryons while they produce a big spin-orbit force in NN system. A unified description of light and strange baryon spectra calculated in a semirelativistic framework is presented. It is demonstrated that the same short-range part of spin-spin interaction between the constituent quarks induces a strong short-range repulsion in $NN...
Valley Singularities and Baryon Number Violation
Provero, P
1994-01-01
We consider the valley--method computation of the inclusive cross section of baryon number violating processes in the Standard Model. We show that any physically correct model of the valley action should present a singularity in the saddle point valley parameters as functions of the energy of the process. This singularity prevents the saddle point configuration from collapsing into the perturbative vacuum.
Baryon Spectroscopy - Recent results from the Crystal Barrel Experiment at ELSA -*
Directory of Open Access Journals (Sweden)
Schmidt C.
2010-04-01
Full Text Available To understand the spectrum and the properties of baryon resonances, the CBELSA/TAPS experiment investigates the photoproduction oﬀ the nucleon using linearly, circularly polarized or unpolarized photons impinging on a polarized or unpolarized target. Preliminary results on ﬁrst double polarization observables have been obtained for the reactions $vec{gamma}{p}$ → pπ0 and $vec{gamma}{p}$ → pη using both circular and linear polarized photons on a longitudinally polarized target. This data will ﬁnally provide important information for the partial wave analyzes used to extract the resonances from the data.
Improved Unitarized Heavy Baryon Chiral Perturbation Theory for $\\pi N $ Scattering
Nicola, A G; Peláez, J R; Ruiz-Arriola, E
2000-01-01
We show how the unitarized description of pion nucleon scattering within Heavy Baryon Chiral Perturbation Theory can be considerably improved, by a suitable reordering of the expansion over the nucleon mass. Within this framework, the $\\Delta$ resonance and its associated pole can be recovered from the chiral parameters obtained from low-energy determinations. In addition, we can obtain a good description of the six $S$ and $P$ wave phase shifts in terms of chiral parameters with a natural size and compatible with the Resonance Saturation Hypothesis.
Electromagnetic production of hyperon resonances
Energy Technology Data Exchange (ETDEWEB)
K. Hicks, D. Keller, W. Tang
2011-10-01
The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the {Lambda}(1405) resonance; a strong suggestion of meson cloud effects in the structure of the {Sigma}(1385) resonance; data from K* photoproduction that will test the existence of the purported K{sub 0}(800)$ meson. Properties of other hyperon resonances will also be studied in the near future.
Magnetic moments of negative-parity baryons in QCD
Aliev, T M
2014-01-01
Using the most general form of the interpolating current for the octet baryons, the magnetic moments of the negative-parity baryons are calculated within the light-cone sum rules. The contributions coming from diagonal transitions of the positive-parity baryons, and also from non-diagonal transition between positive and negative-parity baryons are eliminated by considering the combinations of different sum rules corresponding to the different Lorentz structures. A comparison of our results on magnetic moments of the negative-parity baryons with the other approaches existing in literature is presented.
Baryon number violation catalysed by grand unified monopoles
Ellis, Jonathan Richard; Olive, Keith A
1982-01-01
It has been recognized for some time that grand unified monopoles may catalyze Delta B not=0 processes. The authors obtain model-independent upper bounds on the rates for such reactions from the survival of the baryon number generated in the early Universe and from present-day baryon stability. These constraints are compatible with recent estimates of large baryon number violating monopole cross sections, but a monopole flux close to present experimental upper limits could be detectable in forthcoming baryon decay experiments. The authors mention signatures for monopole-induced baryon 'decay' and point out that it could be used to solve the energy crisis.
Holographic black hole engineering at finite baryon chemical potential
Rougemont, Romulo
2016-01-01
This is a contribution for the Proceedings of the Conference Hot Quarks 2016, held at South Padre Island, Texas, USA, 12-17 September 2016. I briefly review some thermodynamic and baryon transport results obtained from a bottom-up Einstein-Maxwell-Dilaton holographic model engineered to describe the physics of the quark-gluon plasma at finite temperature and baryon density. The results for the equation of state, baryon susceptibilities, and the curvature of the crossover band are in quantitative agreement with the corresponding lattice QCD results with $2+1$ flavors and physical quark masses. Baryon diffusion is predicted to be suppressed by increasing the baryon chemical potential.
Strategies for Detecting the Missing Hot Baryons in the Universe
Bregman, Joel N; Miller, Matthew J
2015-01-01
About 30-50% of the baryons in the local Universe are unaccounted for and are thought to be in a hot phase, 10^5.5-10^8 K, due to the gravitational collapse of cosmic filaments, accretion onto virialized systems, and feedback from stars and AGNs. A hot halo (2E6 K) is detected around the Milky Way through the O VII and O VIII resonance lines absorption and emission in the soft X-ray band. Current instruments are not sensitive enough to detect this gas in absorption around other galaxies and galaxy groups, the two most likely sites. We show that resonant line absorption by this hot gas can be detected with current technology, with a collecting area exceeding about 300 cm^2 and a resolution R > 2000. For a few notional X-ray telescope configurations, we calculate the differential number of O VII and O VIII absorbers as a function of equivalent width through redshift space, dN/dz. We show that if other galaxies have a hot halo like the Milky Way, their absorption should be detectable out to and possibly beyond t...
A Study of Excited Charm-Strange Baryons withEvidence for new Baryons Xi_c(3055)+ and Xi_c(3123)+
Energy Technology Data Exchange (ETDEWEB)
Collaboration, The BABAR; Aubert, B.
2007-10-30
We present a study of excited charm-strange baryon states produced in e{sup +}e{sup -} annihilations at or near a center-of-mass energy of 10.58 GeV, in a data sample with an integrated luminosity of 384 fb{sup -1} recorded with the BABAR detector at the PEP-II e+e storage rings at the Stanford Linear Accelerator Center. We study strong decays of charm-strange baryons to {Lambda}{sub c}{sup +}K{sub S}{sup 0}, {Lambda}{sub c}{sup +}K{sup -}, {Lambda}{sub c}{sup +}K{sup -}{pi}{sup +}, {Lambda}{sub c}{sup +}K{sub S}{sup 0}{pi}{sup -}, {Lambda}{sub c}{sup +}K{sub S}{sup 0}{pi}{sup -}{pi}{sup +}, {Lambda}{sub c}{sup +}K{sup -}{pi}{sup -}{pi}{sup +}. This study confirms the existence of the states {Xi}{sub c}(2980){sup +}, {Xi}{sub c}(3077){sup +}, and {Xi}{sub c}(3077){sup -}, with a more accurate determination of the {Xi}{sub c}(2980){sup +} mass and width. We also present evidence for two new states, {Xi}{sub c}(3055){sup +} and {Xi}{sub c}(3123){sup +}, decaying through the intermediate resonant modes {Sigma}{sub c}(2455){sup ++}K{sup -} and {Sigma}{sub c}(2520){sup ++}K{sup -}, respectively. For each of these baryons, we measure the yield in each final state, determine the statistical significance, and calculate the product of the production cross-section and branching fractions. We also measure the masses and widths of these excited charm-strange baryons.
Two Baryons with Twisted Boundary Conditions
Energy Technology Data Exchange (ETDEWEB)
Briceno, Raul [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Davoudi, Zohreh [Univ. of Washington, Seattle, WA (United States) and Institute for Nuclear Theory, Seattle, WA (United States); Luu, Thomas [Lawrence Livermore National Laboratory, Livermore, CA (United States); Savage, Martin [Univ. of Washington, Seattle, WA (United States) and Institute for Nuclear Theory, Seattle, WA (United States)
2014-04-01
The quantization condition for two particle systems with arbitrary number of two-body open coupled-channels, spin and masses in a finite cubic volume is presented. The condition presented is in agreement with all previous studies of two-body systems in a finite volume. The result is fully relativistic and holds for all momenta below inelastic thresholds and is exact up to exponential volume corrections that are governed by m{sub {pi}} L, where m{sub {pi}} is the pion mass and L is the spatial extent of my box. Its implication for the studies of coupled-channel baryon-baryon systems is discussed, and the necessary tools for implementing the formalism are review.
Baryon Spectrum Analysis using Covariant Constraint Dynamics
Whitney, Joshua; Crater, Horace
2012-03-01
The energy spectrum of the baryons is determined by treating each of them as a three-body system with the interacting forces coming from a set of two-body potentials that depend on both the distance between the quarks and the spin and orbital angular momentum coupling terms. The Two Body Dirac equations of constraint dynamics derived by Crater and Van Alstine, matched with the quasipotential formalism of Todorov as the underlying two-body formalism are used, as well as the three-body constraint formalism of Sazdjian to integrate the three two-body equations into a single relativistically covariant three body equation for the bound state energies. The results are analyzed and compared to experiment using a best fit method and several different algorithms, including a gradient approach, and Monte Carlo method. Results for all well-known baryons are presented and compared to experiment, with good accuracy.
The Baryonic Tully-Fisher Relation.
McGaugh; Schombert; Bothun; de Blok WJ
2000-04-20
We explore the Tully-Fisher relation over five decades in stellar mass in galaxies with circular velocities ranging over 30 less, similarVc less, similar300 km s-1. We find a clear break in the optical Tully-Fisher relation: field galaxies with Vc less, similar90 km s-1 fall below the relation defined by brighter galaxies. These faint galaxies, however, are very rich in gas; adding in the gas mass and plotting the baryonic disk mass Md=M*+Mgas in place of luminosity restores the single linear relation. The Tully-Fisher relation thus appears fundamentally to be a relation between rotation velocity and total baryonic mass of the form Md~V4c.
A Schwarzschild-like model for baryons
Singleton, D.; Yoshida, A.
2002-06-01
We present a toy model of baryons using singular solutions of the SU(2) Yang-Mill-Higgs (YMH) field equations, which bears some similarity to the Schwarzschild solution of general relativity. The SU (2) solutions are used as a background field into which a scalar, SU (2) test particle is placed. This can be compared to placing an electrically charged particle in a Coulomb background field, except the SU (2) YMH solutions are singular on a spherical membrane thus trapping (confining) the test particle inside the sphere in a manner similar to certain bag models of baryons. An interesting consequence of this model is that the composite system is a fermion even though the original Lagrangian contains only bosonic fields.
Baryon and time asymmetries of the universe
Barnaveli, A T; Barnaveli, Andro; Gogberashvili, Merab
1995-01-01
This paper is devoted to the investigation of connection between two apparent asymmetries of the nature --- time-asymmetry and Baryon Asymmetry of the Universe (BAU). The brief review of this subjects is given. We consider the particle behavior in curved space-time and the possibility of T- and CPT-violation by the universe expansion. If these symmetries are violated we can dispense with the nonequilibrium condition which is usualy considered as the one of necessary ingredients for BAU-generation. Such mechanism of GUT-scale baryogenesis can provide the observed value of baryon asymmetry. We show this on the example of minimal SU(5) model which usually fails to explain the observed BAU without taking into account gravitational effects. Predominance of matter over antimatter and the cosmological arrow of time (the time-direction in which the Universe expands) seem to be connected facts and, possibly, BAU is the one of observable facts of CPT-violation in nature.
Energy Technology Data Exchange (ETDEWEB)
Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2016-04-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015 (Fig.~1). A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions; what is needed to understand the physics of resonances in QCD?; where does QCD lead us to expect resonances with exotic quantum numbers?; and what experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus.This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2016-04-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Lutz, Matthias F M; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B; Metag, Volker; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Steve L; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2015-01-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with ${\\it up}$, ${\\it down}$ and ${\\it strange}$ quark content were considered. For heavy-light and heavy-heavy meson systems, those with ${\\it charm}$ quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
A Heavy Quark Symmetry Approach to Baryons
Energy Technology Data Exchange (ETDEWEB)
Albertus, C. [Departamento de Fisica Moderna. Facultad de Ciencias, Universidad de Granada, E-18071 Granada (Spain); Amaro, J.E. [Departamento de Fisica Moderna. Facultad de Ciencias, Universidad de Granada, E-18071 Granada (Spain); Hernandez, E. [Grupo de Fisica Nuclear. Facultad de Ciencias, Universidad de Salamanca, E-37008 Salamanca (Spain); Nieves, J. [Departamento de Fisica Moderna. Facultad de Ciencias, Universidad de Granada, E-18071 Granada (Spain)
2005-06-13
We evaluate different properties of baryons with a heavy c or b quark. The use of Heavy Quark Symmetry (HQS) provides with an important simplification of the non relativistic three body problem which can be solved by means of a simple variational approach. This scheme is able to reproduce previous results obtained with more involved Faddeev calculations. The resulting wave functions are parametrized in a simple manner, and can be used to calculate further observables.
Baryon currents in QCD with compact dimensions
Lucini, B; Pica, C; Lucini, Biagio; Patella, Agostino; Pica, Claudio
2007-01-01
On a compact space with non-trivial cycles, for sufficiently small values of the radii of the compact dimensions, SU(N) gauge theories coupled with fermions in the fundamental representation spontaneously break charge conjugation, time reversal and parity. We show at one loop in perturbation theory that physical signature for this phenomenon is a non-zero baryonic current wrapping around the compact directions. The persistence of this current beyond the perturbative regime is checked by lattice simulations.
Understanding the baryon and meson spectra
Energy Technology Data Exchange (ETDEWEB)
Pennington, Michael R. [JLAB
2013-10-01
A brief overview is given of what we know of the baryon and meson spectra, with a focus on what are the key internal degrees of freedom and how these relate to strong coupling QCD. The challenges, experimental, theoretical and phenomenological, for the future are outlined, with particular reference to a program at Jefferson Lab to extract hadronic states in which glue unambiguously contributes to their quantum numbers.
Baryons in chiral constituent quark model
Glozman, L Ya
1996-01-01
Beyond the spontaneous chiral symmetry breaking scale light and strange baryons should be considered as systems of three constituent quarks with an effective confining interaction and a flavor-spin chiral interaction that is mediated by the octet of Goldstone bosons (pseudoscalar mesons) between the constituent quarks. One cannot exclude, however, the possibility that this flavor-spin interaction has an appreciable vector- and higher meson exchange component.
Charmed bottom baryon spectroscopy from lattice QCD
Brown, Zachary S; Meinel, Stefan; Orginos, Kostas
2014-01-01
We calculate the masses of baryons containing one, two, or three heavy quarks using lattice QCD. We consider all possible combinations of charm and bottom quarks, and compute a total of 36 different states with $J^P = \\frac12^+$ and $J^P = \\frac32^+$. We use domain-wall fermions for the up, down, and strange quarks, a relativistic heavy-quark action for the charm quarks, and nonrelativistic QCD for the bottom quarks. Our analysis includes results from two different lattice spacings and seven different pion masses. We perform extrapolations of the baryon masses to the continuum limit and to the physical pion mass using $SU(4|2)$ heavy-hadron chiral perturbation theory including $1/m_Q$ and finite-volume effects. For the 14 singly heavy baryons that have already been observed, our results agree with the experimental values within the uncertainties. We compare our predictions for the hitherto unobserved states with other lattice calculations and quark-model studies.
Baryons, Neutrinos, Feedback and Weak Gravitational Lensing
Harnois-Déraps, Joachim; Viola, Massimo; Heymans, Catherine
2014-01-01
(Abridged) The effect of baryonic feedback on the dark matter mass distribution is generally considered to be a nuisance to weak gravitational lensing. Measurements of cosmological parameters are affected as feedback alters the cosmic shear signal on angular scales smaller than a few arcminutes. Recent progress on the numerical modelling of baryon physics has shown that this effect could be so large that, rather than being a nuisance, the effect can be constrained with current weak lensing surveys, hence providing an alternative astrophysical insight on one of the most challenging questions of galaxy formation. In order to perform our analysis, we construct an analytic fitting formula that describes the effect of the baryons on the mass power spectrum. This fitting formula is based on three scenarios of the OWL hydrodynamical simulations. It is specifically calibrated for $z<1.5$, where it models the simulations to an accuracy that is better than $2\\%$ for scales $k<10 h\\mbox{Mpc}^{-1}$ and better than ...
Tidal Dwarf Galaxies and Missing Baryons
Directory of Open Access Journals (Sweden)
Frederic Bournaud
2010-01-01
Full Text Available Tidal dwarf galaxies form during the interaction, collision, or merger of massive spiral galaxies. They can resemble “normal” dwarf galaxies in terms of mass, size, and become dwarf satellites orbiting around their massive progenitor. They nevertheless keep some signatures from their origin, making them interesting targets for cosmological studies. In particular, they should be free from dark matter from a spheroidal halo. Flat rotation curves and high dynamical masses may then indicate the presence of an unseen component, and constrain the properties of the “missing baryons,” known to exist but not directly observed. The number of dwarf galaxies in the Universe is another cosmological problem for which it is important to ascertain if tidal dwarf galaxies formed frequently at high redshift, when the merger rate was high, and many of them survived until today. In this paper, “dark matter” is used to refer to the nonbaryonic matter, mostly located in large dark halos, that is, CDM in the standard paradigm, and “missing baryons” or “dark baryons” is used to refer to the baryons known to exist but hardly observed at redshift zero, and are a baryonic dark component that is additional to “dark matter”.
Fragmentation Functions for Heavy Baryons in the Recombination Model
Institute of Scientific and Technical Information of China (English)
彭茹
2011-01-01
Using the shower parton distributions determined by the recombination model, we predict the fragmentation functions for heavy baryons. Then we obtain the completed fragmentation functions of heavy quarks (c and b) splitting into their hadrons (mesons and baryons containing one heavy valence quark). The calculated process shows that the fragmentation functions for mesons and baryons are not independent if the hadronization of the shower partons is taken into account.%Using the shower parton distributions determined by the recombination model,we predict the fragmentation functions for heavy baryons.Then we obtain the completed fragmentation functions of heavy quarks(c and b)splitting into their hadrons(mesons and baryons containing one heavy valence quark).The calculated process shows that the fragmentation functions for mesons and baryons are not independent if the hadronization of the shower partons is taken into account.
High statistics analysis using anisotropic clover lattices: (III) Baryon-baryon interactions
Energy Technology Data Exchange (ETDEWEB)
Beane, S; Detmold, W; Lin, H; Luu, T; Orginos, K; Savage, M; Torok, A; Walker-Loud, A
2010-01-19
Low-energy baryon-baryon interactions are calculated in a high-statistics lattice QCD study on a single ensemble of anisotropic clover gauge-field configurations at a pion mass of m{sub {pi}} {approx} 390 MeV, a spatial volume of L{sup 3} {approx} (2.5 fm){sup 3}, and a spatial lattice spacing of b {approx} 0.123 fm. Luescher's method is used to extract nucleon-nucleon, hyperon-nucleon and hyperon-hyperon scattering phase shifts at one momentum from the one- and two-baryon ground-state energies in the lattice volume. The isospin-3/2 N{Sigma} interactions are found to be highly spin-dependent, and the interaction in the {sup 3}S{sub 1} channel is found to be strong. In contrast, the N{Lambda} interactions are found to be spin-independent, within the uncertainties of the calculation, consistent with the absence of one-pion-exchange. The only channel for which a negative energy-shift is found is {Lambda}{Lambda}, indicating that the {Lambda}{Lambda} interaction is attractive, as anticipated from model-dependent discussions regarding the H-dibaryon. The NN scattering lengths are found to be small, clearly indicating the absence of any fine-tuning in the NN-sector at this pion mass. This is consistent with our previous Lattice QCD calculation of NN interactions. The behavior of the signal-to-noise ratio in the baryon-baryon correlation functions, and in the ratio of correlation functions that yields the ground-state energy splitting is explored. In particular, focus is placed on the window of time slices for which the signal-to-noise ratio does not degrade exponentially, as this provides the opportunity to extract quantitative information about multi-baryon systems.
Baryons as Fock states of 3,5,... Quarks
Energy Technology Data Exchange (ETDEWEB)
Dmitri Diakonov; Victor Petrov
2004-09-01
We present a generating functional producing quark wave functions of all Fock states in the octet, decuplet and antidecuplet baryons in the mean field approximation, both in the rest and infinite momentum frames. In particular, for the usual octet and decuplet baryons we get the SU(6)-symmetric wave functions for their 3-quark component but with specific corrections from relativism and from additional quark-antiquark pairs. For the exotic antidecuplet baryons we obtain the 5-quark wave function.
Calculating Masses of Pentaquarks Composed of Baryons and Mesons
Directory of Open Access Journals (Sweden)
M. Monemzadeh
2016-01-01
Full Text Available We consider an exotic baryon (pentaquark as a bound state of two-body systems composed of a baryon (nucleon and a meson. We used a baryon-meson picture to reduce a complicated five-body problem to simple two-body problems. The homogeneous Lippmann-Schwinger integral equation is solved in configuration space by using one-pion exchange potential. We calculate the masses of pentaquarks θc(uuddc¯ and θb(uuddb¯.
Spectroscopy of singly, doubly, and triply bottom baryons
Wei, Ke-Wei; Liu, Na; Wang, Qian-Qian; Guo, Xin-Heng
2016-01-01
Recently, many singly bottom baryons have been established experimentally, but no doubly or triply bottom baryon has been observed. Under the Regge phenomenology, the mass of a ground state unobserved doubly or triply bottom baryon is expressed as a function of masses of the well established light baryons and singly bottom baryons. (For example, we write the mass of $\\Omega_{bbb}$ as a function of the masses of well established light baryons ($\\Sigma^{*}$, $\\Xi^{*}$, $\\Omega$) and singly bottom baryons ($\\Sigma_b^{*}$, $\\Xi_b^{*}$), and give its value to be 14788$\\pm$80 MeV.) After that, we calculate the values of Regge slopes and Regge intercepts for singly, doubly, and triply bottom baryons. (Regge intercepts and slopes, which are usually regarded as fundamental constants of hadron dynamics, are useful for many spectral and nonspectral purposes.) Then, masses of the orbitally excited singly, doubly, and triply bottom baryons are estimated. The isospin splitting is also determined, $M_{\\Xi_{bb}^{-}}-M_{\\Xi_{...
Hypermagnetic Fields and Baryon Asymmetry from Pseudoscalar Inflation
Anber, Mohamed M
2015-01-01
We show that maximally helical hypermagnetic fields produced during pseudoscalar inflation can generate the observed baryon asymmetry of the universe via the B+L anomaly in the Standard Model. We find that most of the parameter space of pseudoscalar inflation that explains the cosmological data leads to baryon overproduction, hence the models of natural inflation are severely constrained. We also point out a connection between the baryon number and topology of the relic magnetic fields. Both the magnitude and sign of magnetic helicity can be detected in future diffuse gamma ray data. This will be a smoking gun evidence for a link between inflation and the baryon asymmetry of the Universe.
Notes on exotic anti-decuplet of baryons
Polyakov, M V
2004-01-01
We emphasize the importance of identifying non-exotic SU(3) partners of the Theta^+ pentaquark, and indicate possible ways how to do it. We also use the soliton picture of baryons to relate Reggeon couplings of various baryons. These relations are used to estimate the Theta^+ production cross section in high energy processes. We show that the corresponding cross sections are significantly suppressed relative to the production cross sections of usual baryons. Finally, we present spin non-flip form factors of the anti-decuplet baryons in the framework of the chiral quark soliton model.
Magnetic Moments of Baryons with a Heavy Quark
Weigel, H
2003-01-01
We compute magnetic moments of baryons with a heavy quark in the bound state approach for heavy baryons. In this approach the heavy baryon is considered as a heavy meson bound to a light baryon. The latter is represented as a soliton excitation of light meson fields. We obtain the magnetic moments by sandwiching pertinent components of the electromagnetic current operator between the bound state wave--functions. We extract this current operator from the coupling to the photon field after extending the action to be gauge invariant.
Search for CP violation in baryon decays at LHCb
CERN. Geneva
2016-01-01
The phenomenon of CP violation has been observed in the K- and B-meson systems, but not yet with any baryonic particle. We report on searches for CP violation in baryon decays at LHCb using Run I data. We find evidence for CP violation in Lambda0b -> p pi- pi+ pi- decays with a statistical significance corresponding to 3.3 standard deviations, including systematic uncertainties. This represents the first evidence of CP violation in the baryon sector. An overview of other recent results of baryon decays will be presented, along with some highlights of the charmless B-decay programme.
Dark Matter in Lepto-Baryonic Left-Right Theories
Patra, Sudhanwa
2015-01-01
A Lepto-Baryonic Left-Right symmetric theory is considered where leptons and baryons are local gauge symmetries. These theories are generally anomalous and the possible gauge anomaly free solutions for these theories are presented here. This paper also shows different ways in which Lepto-Baryonic Left-Right theories are broken down to Standard Model gauge group which further breaks down to low energy by SM Higgs boson. It is found that the neutral component of fermion triplets can be a viable dark matter candidate originally introduced for gauge anomaly cancellation. The other dark matter possibilities within this Lepto-Baryonic Left-Right symmetric theories are also presented.
One-loop corrections to the baryon axial vector current
Indian Academy of Sciences (India)
M A Hernández-Ruíz
2012-10-01
The symmetry breaking corrections to the pion–baryon couplings vanish to first order in $1/N_{c}$, where $N_{c}$ is the number of colours. Loop graphs with octet and decuplet intermediate states cancel to various orders in $N_{c}$ as a consequence of the large-$N_{c}$ spin-flavour symmetry of QCD baryons. The baryon axial vector current is computed at one-loop order in heavy baryon chiral perturbation theory in the large Nc limit. $1/N_{c}$ corrections in the case of $g_{A}$ in QCD are presented here.
Quark-Pauli effects in three octet-baryons
Nakamoto, C
2016-01-01
To sustain a neutron star with about two times the solar mass, multi baryons including hyperons are expected to produce repulsive effects in the interior of its high baryon-density region. To examine possible quark-Pauli repulsion among the baryons, we solve the eigenvalue problem of the quark antisymmetrizer for three octet-baryons that are described by most compact spatial configurations. We find that the Pauli blocking effect is weak in the $\\Lambda nn$ system, while it is strong in the $\\Sigma^-nn$ system. The appearance of the $\\Sigma^-$ hyperon is suppressed in the neutron star interior but no quark-Pauli repulsion effectively works for the $\\Lambda$ hyperon.
Search for narrow baryons in pi /sup -/p elastic scattering at large angles
Baillon, Paul; Benayoun, M; Chauveau, J; Chew, D; Ferro-Luzzi, M; Kahane, J; Lellouch, D; Leruste, P; Liaud, P; Moreau, F; Perreau, J M; Séguinot, Jacques; Sené, R; Tocqueville, J; Urban, M
1980-01-01
Hoping to find resonant structures in the momentum dependence of pi /sup -/p elastic scattering the authors have measured the differential cross section for this reaction at c.m. angles near 90 degrees . An intense pion beam ( approximately=10/sup 7/ pi /s) has been used, together with a high incident momentum resolution (dP/P approximately =2*10/sup -4/), to scan the region of laboratory momenta from 5.75 to 13.02 GeV/c (c.m. energy from 3.42 to 5.03 GeV). The sensitivity attained by the experiment is such that signals would have been seen corresponding to the formation of non-strange baryon resonances having width larger than approximately=0.1 MeV and elasticity larger than a few per cent. Within these limits no resonances were sighted. (4 refs) .
Baryon Number, Strangeness and Electric Charge Fluctuations in QCD at High Temperature
Cheng, M; Jung, C; Karsch, F; Kaczmarek, O; Laermann, E; Mawhinney, R D; Miao, C; Petreczky, P; Schmidt, C; Söldner, W
2008-01-01
We analyze baryon number, strangeness and electric charge fluctuations as well as their correlations in QCD at high temperature. We present results obtained from lattice calculations performed with an improved staggered fermion action (p4-action) at two values of the lattice cut-off with almost physical up and down quark masses and a physical value for the strange quark mass. We compare these results, with an ideal quark gas at high temperature and a hadron resonance gas model at low temperature. We find that fluctuations and correlations are well described by the former already for temperatures about 1.5 times the transition temperature. At low temperature qualitative features of the lattice results are well described by a hadron resonance gas model. Higher order cumulants, which become increasingly sensitive to the light pions, however show deviations from a resonance gas in the vicinity of the transition temperature.
Search for doubly charmed baryons and study of charmed strange baryons at Belle
Kato, Y; Adachi, I; Aihara, H; Asner, D M; Aushev, T; Bakich, A M; Bala, A; Ban, Y; Bhardwaj, V; Bhuyan, B; Bobrov, A; Bonvicini, G; Bozek, A; Bračko, M; Browder, T E; Červenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chilikin, K; Chistov, R; Cho, K; Chobanova, V; Choi, Y; Cinabro, D; Dalseno, J; Danilov, M; Doležal, Z; Drásal, Z; Drutskoy, A; Dutta, D; Dutta, K; Eidelman, S; Farhat, H; Fast, J E; Ferber, T; Gaur, V; Gabyshev, N; Ganguly, S; Garmash, A; Gillard, R; Goh, Y M; Golob, B; Haba, J; Hayasaka, K; Hayashii, H; He, X H; Horii, Y; Hoshi, Y; Hou, W -S; Hsiung, Y B; Inami, K; Ishikawa, A; Iwasaki, Y; Iwashita, T; Jaegle, I; Julius, T; Kang, J H; Kato, E; Kawasaki, T; Kiesling, C; Kim, D Y; Kim, H J; Kim, J B; Kim, J H; Kim, M J; Kim, Y J; Klucar, J; Ko, B R; Kodyš, P; Korpar, S; Krokovny, P; Kuhr, T; Kuzmin, A; Kwon, Y -J; Lee, S -H; Li, J; Li, Y; Gioi, L Li; Libby, J; Liu, Y; Liventsev, D; Matvienko, D; Miyabayashi, K; Miyata, H; Mizuk, R; Moll, A; Muramatsu, N; Mussa, R; Nagasaka, Y; Nakano, E; Nakao, M; Nayak, M; Nedelkovska, E; Ng, C; Niiyama, M; Nisar, N K; Nishida, S; Nitoh, O; Ogawa, S; Okuno, S; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Park, H K; Pedlar, T K; Peng, T; Pestotnik, R; Petrič, M; Piilonen, L E; Ritter, M; Röhrken, M; Rostomyan, A; Sahoo, H; Saito, T; Sakai, Y; Sandilya, S; Santelj, L; Sanuki, T; Savinov, V; Schneider, O; Schnell, G; Schwanda, C; Semmler, D; Senyo, K; Seon, O; Shapkin, M; Shen, C P; Shibata, T -A; Shiu, J -G; Shwartz, B; Sibidanov, A; Sohn, Y -S; Sokolov, A; Solovieva, E; Stanič, S; Starič, M; Steder, M; Sumihama, M; Sumiyoshi, T; Tamponi, U; Tanida, K; Tatishvili, G; Teramoto, Y; Uchida, M; Uehara, S; Uglov, T; Unno, Y; Uno, S; Van Hulse, C; Vanhoefer, P; Varner, G; Vinokurova, A; Vorobyev, V; Wagner, M N; Wang, C H; Wang, M -Z; Wang, P; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yamashita, Y; Yashchenko, S; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A
2013-01-01
We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb^-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We search for doubly charmed baryons Xi_cc^+(+) with the Lambda_c^+K^-pi^+(pi^+) and Xi_c^0pi^+(pi^+) final states. No significant signal is observed. We also search for two excited charmed strange baryons, Xi_c(3055)^+ and Xi_c(3123)^+ with the Sigma_c^++(2455)K^- and Sigma_c^++(2520)K^- final states. The Xi_c(3055)^+ signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Xi_c(3123)^+ is seen. We also study properties of the Xi_c(2645)^+ and measure a width of 2.6 +- 0.2 (stat) +- 0.4 (syst) MeV/c^2, which is the first significant determination.
Papastergis, Emmanouil; Cattaneo, Andrea; Huang, Shan; Giovanelli, Riccardo; Haynes, Martha P.
2012-01-01
We use both an HI-selected and an optically-selected galaxy sample to directly measure the abundance of galaxies as a function of their "baryonic" mass (stars + atomic gas). Stellar masses are calculated based on optical data from the Sloan Digital Sky Survey (SDSS) and atomic gas masses are calcula
a Relativistic Calculation of Baryon Masses
Giammarco, Joseph Michael
1990-01-01
We calculate ground state baryon masses using a saddle-point variational (SPV) method, which permits us the use of fully relativistic 4-component Dirac spinors without the need for positive energy projection operators. This variational approach has been shown to work in the relativistic domain for one particle in an external potential (Dirac equation). We have extended its use to the relativistic 3-body Breit equation. Our procedure is as follows: we pick a trial wave function having the appropriate spin, flavor and color dependence. This can be accomplished with a non-symmetric relativistic spatial wave function having two different size parameters if the the first two quarks are always chosen to be identical. We than calculate an energy eigenvalue for the particle state and vary the parameters in our wave function to search for a "saddle-point". We minimize the energy with respect to the two size parameters and maximize with respect to two parameters that measure the contribution from the negative-energy states. This gives the baryon's mass as a function of four input parameters: the masses of the up, down and strange quarks (m_{u=d },m_{s}), and the strength of the coupling constants for the potentials ( alpha_{s},mu). We do this for the eight Baryon ground states and fit these to experimental data. This fit gives the values of the input parameters. For the potentials we use a coulombic term to represent one-gluon exchange and a linear term for confinement. For both terms we include a retardation term required by relativity. We also add delta function and spin-spin terms to account for the large contribution of the coulomb interaction at the origin. The results we obtain from our SPV method are in good agreement with experimental data. The actual search for the saddle-point parameters and the fitting of the quark masses and the values of the coupling strengths was done on a CDC Cyber 860.
Flavour Oscillations in Dense Baryonic Matter
Filip, Peter
2017-01-01
We suggest that fast neutral meson oscillations may occur in a dense baryonic matter, which can influence the balance of s/¯s quarks in the nucleus-nucleus and proton-nucleus interactions, if primordial multiplicities of neutral K 0, mesons are sufficiently asymmetrical. The phenomenon can occur even if CP symmetry is fully conserved, and it may be responsible for the enhanced sub-threshold production of multi-strange hyperons observed in the low-energy A+A and p+A interactions.
Non-baryonic dark matter in cosmology
Del Popolo, A.
2013-07-01
This paper is based on lectures given at the IX Mexican School on Gravitation and Mathematical Physics. The lectures (as the paper) were a broad-band review of the current status of non-baryonic dark matter research. I start with a historical overview of the evidences of dark matter existence, then I discuss how dark matter is distributed from small scale to large scale, and I then verge the attention to dark matter nature: dark matter candidates and their detection. I finally discuss some of the limits of the ΛCDM model, with particular emphasis on the small scale problems of the paradigm.
SU(3) flavour breaking and baryon structure
Energy Technology Data Exchange (ETDEWEB)
Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Shanahan, P.; Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, School of Chemistry and Physics; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Collaboration: QCDSF/UKQCD Collaboration
2013-11-15
We present results from the QCDSF/UKQCD collaboration for hyperon electromagnetic form factors and axial charges obtained from simulations using N{sub f}=2+1 flavours of O(a)-improved Wilson fermions. We also consider matrix elements relevant for hyperon semileptonic decays. We find flavour-breaking effects in hyperon magnetic moments which are consistent with experiment, while our results for the connected quark spin content indicates that quarks contribute more to the spin of the {Xi} baryon than they do to the proton.
Baryon instability search in large detectors
Energy Technology Data Exchange (ETDEWEB)
Moscoso, L. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee
1996-08-01
Nucleon decay appears as a consequence of models trying to explain the baryon-antibaryon asymmetry. This has motivated 15 years ago many underground experiments devoted to the search of proton and neutron decay. A very large number of decay channels have been investigated and no evidence has been found yielding lower limits on lifetime which rule out the minimal SU(5) Grand Unified Theory predictions and put severe constraints on more complicated models. Next generation experiments like Super-Kamiokande, which is starting to take data now, ICARUS, whose a 600 ton prototype is under construction, will be sensitive to more complicated models predicting larger lifetimes. (author). 16 refs.
Magnetic Polarizability of Diquarks in Baryons
Filip, Peter
2014-01-01
We study the response of diquark wave function in \\Lambda-type baryons to strong magnetic fields. It is found that quantum state of J=0 diquark (ud) in the magnetic field changes due to magnetic polarizability, and constituent quarks in (ud) diquark become polarized. The phenomenon influences polarized quark distribution functions \\Delta u(x) and \\Delta d(x), which therefore may be sensitive to the internal electromagnetic fields in hypernuclei. We also speculate, that strange quark polarization in nucleon may originate from the interaction of virtual (ss') quark pairs with the intrinsic magnetic field of nucleon B $\\approx$ 10^13 T.
Baryons in Massive Gross-Neveu Models
Thies, M; Thies, Michael; Urlichs, Konrad
2005-01-01
Baryons in the large N limit of (1+1)-dimensional Gross-Neveu models with either discrete or continuous chiral symmetry have long been known. We generalize their construction to the case where the symmetry is explicitly broken by a bare mass term in the Lagrangian. In the discrete symmetry case, the exact solution is found for arbitrary bare fermion mass, using the Hartree-Fock approach. In the continuous symmetry case, a derivative expansion allows us to rederive a formerly proposed Skyrme-type model and to compute systematically corrections to the leading order description based on an effective sine-Gordon theory.
Non-Baryonic Dark Matter in Cosmology
Del Popolo, A
2014-01-01
This paper is a broad-band review of the current status of non-baryonic dark matter research. I start with a historical overview of the evidences of dark matter existence, then I discuss how dark matter is distributed from small scale to large scale, and I then verge the attention to dark matter nature: dark matter candidates and their detection. I finally discuss some of the limits of the $\\Lambda$CDM model, with particular emphasis on the small scale problems of the paradigm.
High Statistics Analysis using Anisotropic Clover Lattices: (III) Baryon-Baryon Interactions
Energy Technology Data Exchange (ETDEWEB)
Beane, Silas [Univ. of New Hampshire, Durham, NH (United States); Detmold, William [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Huey-Wen [Univ. of Washington, Seattle, WA (United States); Luu, Thomas C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Orginos, Kostas [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Savage, Martin [Univ. of Washington, Seattle, WA (United States); Torok, Aaron M. [Indiana Univ., Bloomington, IN (United States). Dept. of Physics; Walker-Loud, Andre [College of William and Mary, Williamsburg, VA (United States)
2010-03-01
Low-energy baryon-baryon interactions are calculated in a high-statistics lattice QCD study on a single ensemble of anisotropic clover gauge-field configurations at a pion mass of m_pi ~ 390 MeV, a spatial volume of L^3 ~ (2.5 fm)^3, and a spatial lattice spacing of b ~ 0.123 fm. Luscher’s method is used to extract nucleon-nucleon, hyperon-nucleon and hyperon-hyperon scattering phase shifts at one momentum from the one- and two-baryon ground-state energies in the lattice volume. The N-Sigma interactions are found to be highly spin-dependent, and the interaction in the ^3 S _1 channel is found to be strong. In contrast, the N-Lambda interactions are found to be spin-independent, within the uncertainties of the calculation, consistent with the absence of one-pion-exchange. The only channel for which a negative energy-shift is found is Lambda-Lambda, indicating that the Lambda-Lambda interaction is attractive, as anticipated from model-dependent discussions regarding the H-dibaryon. The NN scattering lengths are found to be small, clearly indicating the absence of any fine-tuning in the NN-sector at this pion mass. This is consistent with our previous Lattice QCD calculation of the NN interactions. The behavior of the signal-to-noise ratio in the baryon-baryon correlation functions, and in the ratio of correlation functions that yields the ground-state energy splitting
Schematic baryon models, their tight binding description and their microwave realization
Sadurní, E; Kuhl, U; Mortessagne, F; Seligman, T H
2013-01-01
A schematic model for baryon excitations is presented in terms of a symmetric Dirac gyroscope, a relativistic model solvable in closed form, that reduces to a rotor in the non-relativistic limit. The model is then mapped on a nearest neighbour tight binding model. In its simplest one-dimensional form this model yields a finite equidistant spectrum. This is experimentally implemented as a chain of dielectric resonators under conditions where their coupling is evanescent and good agreement with the prediction is achieved.
Schematic baryon models, their tight binding description and their microwave realization
Sadurní, E.; Franco-Villafañe, J. A.; Kuhl, U.; Mortessagne, F.; Seligman, T. H.
2013-12-01
A schematic model for baryon excitations is presented in terms of a symmetric Dirac gyroscope, a relativistic model solvable in closed form, that reduces to a rotor in the non-relativistic limit. The model is then mapped on a nearest neighbour tight binding model. In its simplest one-dimensional form this model yields a finite equidistant spectrum. This is experimentally implemented as a chain of dielectric resonators under conditions where their coupling is evanescent and a good agreement with the prediction is achieved.
Manifestation of Conformal Symmetry in the Light Flavor Baryon Sector
Kirchbach, M
2010-01-01
On the AdS_5 cone, conformally compactified to R^1xS^3, a quark-diquark model of light flavor baryons is developed. The system on this manifold is decribed in terms of a scalar conformal equation, gauged by the field of a D3 brane whose transversal dimensions have been conformally warpped over R^1xS^3. Such a system does not result exactly conformally invariant because the gauge potential slightly modifies the conformal centrifugal barrier of the free geodesic motion. Thanks to this, the model describes the correct mass ordering in the P11-S11 pairs through the N spectrum as a combined effect of conformal symmetry breaking, on the one side, and a parity change of the diquark from a scalar at low masses, to a pseudoscalar at higher masses, on the other. We calculate the number of resonances with masses below 2500 MeV needed for the completeness of the above scheme and find a total of 32 "missing" nucleon and Delta states. Their absence or presence in the respective spectra relates to the degree to which confor...
Constituent quark and baryon spectra from a modified Perturbative QCD
Cabo-Montes de Oca, Alejandro; Cabo Montes de Oca, Alejandro; Madrazo, Marcos Rigol
2000-01-01
A recently proposed perturbative expansion for QCD incorporating gluon condensation is employed to evaluate the quark and gluon self-energy corrections in the simplest approximations. The results predict mass values of the order of 1/3 of the nucleon mass for the light quarks u,d and s and a monotonously growing variation with the current mass values. The mass spectrum of the ground states within the various groups of baryonic resonances and a class of vector meson ones is well predicted by the simple addition of the calculated constituent quark masses. In connection with the self-energy, it follows that the gluonic mass shell becomes tachyonic in the considered approximation. In order to obtain the above mentioned results was evaluated as a function of the condensate paramater up to order g^2 and then this parameter fixed to give the accepted numerical value of . The discussion leads us to conjecture that the procedure, after also introducing quark condensates in the same token as the gluonic ones, could a...
Strange decays from strange resonances
Bijker, R
2001-01-01
We discuss the mass spectrum and strong decays of baryon resonances belonging to the N, Delta, Sigma, Lambda, Xi and Omega families in a collective string-like model for the nucleon. We find good overall agreement with the available data. Systematic discrepancies are found for lowlying S-wave states, in particular in the strong decays of N(1535), N(1650), Sigma(1750), Lambda(1405), Lambda(1670) and Lambda(1800).
Strange decays from strange resonances
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
2001-07-01
We discuss the mass spectrum and strong decays of baryon resonances belonging to the N, {delta}, {sigma}, {lambda}, {xi} and {omega} families in a collective string- like model for the nucleon. We find good overall agreement with the available data. Systematic discrepancies are found for low-lying S-wave states, in particular in the strong decays of N(1535), N(1650), {sigma}(1750), {lambda}{sup *}(1405), {lambda}(1670) and {lambda}(1800). (Author)
Nucleon Resonance Transition Form factors
Energy Technology Data Exchange (ETDEWEB)
Burkert, Volker D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mokeev, Viktor I. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Aznauryan, Inna G. [Yerevan Physics Inst. (YerPhI) (Armenia)
2016-08-01
We discuss recent results from CLAS on electromagnetic resonance transition amplitudes and their dependence on the distance scale (Q2). From the comparison of these results with most advanced theoretical calculations within QCD-based approaches there is clear evidence that meson-baryon contributions are present and important at large distances, i.e. small Q2, and that quark core contributions dominate the short distance behavior.
Exotic pentaquarks as Gamov--Teller resonances
Diakonov, Dmitri
2009-01-01
If the number of colors Nc is taken large, baryons and their excitations can be considered in a mean-field approach. We argue that the mean field in baryons breaks spontaneously the spherical and SU(3) flavor symmetries, but retains the SU(2) symmetry of simultaneous rotations in space and isospace. The one-quark and quark-hole excitations in the mean field, together with the SU(3) rotational bands about them determine the spectrum of baryon resonances, which turns out to be in satisfactory accordance with reality when one puts Nc=3. A by-product of this scheme is a confirmation of the light pentaquark baryon Theta+ = uudds-bar as a typical Gamov--Teller resonance long known in nuclear physics. An extension of the same large-Nc logic to charmed (and beauty) baryons leads to a prediction of a decapenta (15)-plet of charmed pentaquarks, two of which, Theta++_c = cuuds-bar and Theta+_c = cudds-bar, may be light and stable with respect to strong decays, and should be looked for.
Baryon octet distribution amplitudes in Wandzura-Wilczek approximation
Energy Technology Data Exchange (ETDEWEB)
Anikin, I.V. [Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics; Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Manashov, A.N. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2015-12-15
We study higher twist distribution amplitudes for the SU{sub F}(3) baryon octet. We identify independent functions for all baryons in the isospin symmetry limit and calculate the Wandzura-Wilczek contributions to the twist-4 and 5 distributions amplitudes.
Baryon magnetic moments in the effective quark Lagrangian approach
Simonov, YA; Tjon, JA; Weda, J; Simonov, Yu A.
2002-01-01
An effective quark Lagrangian is derived from first principles through bilocal gluon field correlators. It is used to write down equations for baryons, containing both perturbative and nonperturbative fields. As a result one obtains magnetic moments of octet and decuplet baryons without the introduc
Evidence for chiral logarithms in the baryon spectrum
Walker-Loud, Andre
2011-01-01
Using precise lattice QCD computations of the baryon spectrum, we present the first direct evidence for the presence of contributions to the baryon masses which are non-analytic in the light quark masses; contributions which are often denoted "chiral logarithms". We isolate the poor convergence of SU(3) baryon chiral perturbation theory to the flavor-singlet mass combination. The flavor-octet baryon mass splittings, which are corrected by chiral logarithms at next to leading order in SU(3) chiral perturbation theory, yield baryon-pion axial coupling constants D, F, C and H consistent with QCD values; the first evidence of chiral logarithms in the baryon spectrum. The Gell-Mann--Okubo relation, a flavor-27 baryon mass splitting, which is dominated by chiral corrections from light quark masses, provides further evidence for the presence of non-analytic light quark mass dependence in the baryon spectrum; we simultaneously find the GMO relation to be inconsistent with the first few terms in a taylor expansion in ...
(Hybrid) Baryons in the Flux-Tube Model
Page, P R
1999-01-01
We construct baryons and hybrid baryons in the non-relativistic flux-tube model of Isgur and Paton. The motion of the flux-tube with the three quark positions fixed, except for centre of mass corrections, is discussed. It is shown that the problem can to an excellent approximation be reduced to the independent motion of a junction and strings.
Finite Volume Effect of Baryons in Strange Hadronic Matter
Institute of Scientific and Technical Information of China (English)
SUN Bao-Xi; LI Lei; NING Ping-Zhi; ZHAO En-Guang
2001-01-01
The finite volume effect of baryons in strange hadronic matter (SHM) is studied within the framework of relativistic mean-field theory. As this effect is concerned, the saturation density of SHM turns lower, and the binding energy per baryon decreases. Its influence to the compression modulus of SHM is also discussed.
Baryon masses with dynamical twisted mass fermions
Alexandrou, C; Koutsou, G; Baron, R; Guichon, P; Brinet, M; Carbonell, J; Drach, V; Liu, Z; Pène, O; Urbach, C
2007-01-01
We present results on the mass of the nucleon and the $\\Delta$ using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of 690-300 MeV on lattices of size 2.1 fm and 2.7 fm. We check for cutoff effects by evaluating these baryon masses on lattices of spatial size 2.1 fm with lattice spacings $a(\\beta=3.9)=0.0855(6)$ fm and $a(\\beta=4.05)=0.0666(6)$ fm, determined from the pion sector and find them to be within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. The nucleon mass at the physical point provides a determination of the lattice spacing. Using heavy baryon chiral perturbation theory at ${\\cal O}(p^3)$ we find $a(\\beta=3.9)=0.0879(12)$ fm, with a systematic error due to the chiral extrapolation estimated to be about the same as the statistical error. This value of the lattice spacing is in good agreement with the value determined from the pion se...
The Compressed Baryonic Matter Experiment at FAIR
Energy Technology Data Exchange (ETDEWEB)
Heuser, Johann M.
2013-05-02
The Compressed Baryonic Matter (CBM) experiment will explore the phase diagram of strongly interacting matter in the region of high net baryon densities. The experiment is being laid out for nuclear collision rates from 0.1 to 10 MHz to access a unique wide spectrum of probes, including rarest particles like hadrons containing charm quarks, or multi-strange hyperons. The physics programme will be performed with ion beams of energies up to 45 GeV/nucleon. Those will be delivered by the SIS-300 synchrotron at the completed FAIR accelerator complex. Parts of the research programme can already be addressed with the SIS-100 synchrotron at the start of FAIR operation in 2018. The initial energy range of up to 11 GeV/nucleon for heavy nuclei, 14 GeV/nucleon for light nuclei, and 29 GeV for protons, allows addressing the equation of state of compressed nuclear matter, the properties of hadrons in a dense medium, the production and propagation of charm near the production threshold, and exploring the third, strange dimension of the nuclide chart. In this article we summarize the CBM physics programme, the preparation of the detector, and give an outline of the recently begun construction of the Facility for Antiproton and Ion Research.
Predictions for masses of bottom baryons
Karliner, Marek; Lipkin, Harry J; Rosner, Jonathan L
2007-01-01
The recent observation of Sigma_b^{+-} (uub and ddb) and Xi_b^- (dsb) baryons at the Tevatron within 2 MeV of our theoretical predictions provides a strong motivation for applying the same theoretical approach, based on modeling the color hyperfine interaction, to predict the masses of other bottom baryons which might be observed in the foreseeable future. For S-wave qqb states we predict M(Omega_b) = 6052.1+-5.6 MeV, M(Omega^*_b) = 6082.8+-5.6 MeV, and M(Xi_b^0) = 5786.7 +- 3.0 MeV. For states with one unit of orbital angular momentum between the b quark and the two light quarks we predict M(Lambda_{b[1/2]}) = 5929+-2 MeV, M(Lambda_{b[3/2]}) = 5940+-2 MeV, M(Xi_{b[1/2]}) = 6106+-4 MeV, and M(Xi_{b[3/2]}) = 6115+-4 MeV.
The Quark Model and $b$ Baryons
Karliner, Marek; Lipkin, Harry J; Rosner, Jonathan L
2008-01-01
The recent observation at the Tevatron of $\\Sigma_b^{\\pm}$ ($uub$ and $ddb$) baryons within 2 MeV of the predicted $\\Sigma_b - \\Lambda_b$ splitting and of $\\Xi_b^-$ $(dsb)$ baryons at the Tevatron within a few MeV of predictions has provided strong confirmation for a theoretical approach based on modeling the color hyperfine interaction. The prediction of $M(\\Xi^-_b) = 5790$ to 5800 MeV is reviewed and similar methods used to predict the masses of the excited states $\\Xi_b^\\prime$ and $\\Xi_b^*$. The main source of uncertainty is the method used to estimate the mass difference $m_b - m_c$ from known hadrons. We verify that corrections due to the details of the interquark potential and to $\\Xi_b$--$\\Xi_b^\\prime$ mixing are small. For S-wave $qqb$ states we predict $M(\\Omega_b) = 6052.1 \\pm 5.6$ MeV, $M(\\Omega^*_b) = 6082.8 \\pm 5.6$ MeV, and $M(\\Xi_b^0) = 5786.7 \\pm 3.0$ MeV. For states with one unit of orbital angular momentum between the $b$ quark and the two light quarks we predict $M(\\Lambda_{b[1/2]}) = 5929...
Doubly heavy baryon spectra guided by lattice QCD
Garcilazo, H; Vijande, J
2016-01-01
This paper provides results for the ground state and excited spectra of three-flavored doubly heavy baryons, $bcn$ and $bcs$. We take advantage of the spin-independent interaction recently obtained to reconcile the lattice SU(3) QCD static potential and the results of nonperturbative lattice QCD for the triply heavy baryon spectra. We show that the spin-dependent potential might be constrained on the basis of nonperturbative lattice QCD results for the spin splittings of three-flavored doubly heavy baryons. Our results may also represent a challenge for future lattice QCD work, because a smaller lattice error could help in distinguishing between different prescriptions for the spin-dependent part of the interaction. Thus, by comparing with the reported baryon spectra obtained with parameters estimated from lattice QCD, one can challenge the precision of lattice calculations. The present work supports a coherent description of singly, doubly and triply heavy baryons with the same Cornell-like interacting poten...
Spectrum of heavy baryons in the quark model
Yoshida, Tetsuya; Hosaka, Atsushi; Oka, Makoto; Sadato, Katsunori
2015-01-01
Single- and double- heavy baryons are studied in the constituent quark model. The model Hamiltonian is chosen as a standard one with two exceptions : (1) The color-Coulomb term depend on quark masses, and (2) an antisymmetric $LS$ force is introduced. Model parameters are fixed by the strange baryon spectra, $\\Lambda$ and $\\Sigma$ baryons. The masses of the observed charmed and bottomed baryons are, then, fairly well reproduced. Our focus is on the low-lying negative-parity states, in which the heavy baryons show specific excitation modes reflecting the mass differences of heavy and light quarks. By changing quark masses from the SU(3) limit to the strange quark mass, further to the charm and bottom quark masses, we demonstrate that the spectra change from the SU(3) symmetry patterns to the heavy quark symmetry ones.
Octet Baryon Electromagnetic Form Factors in a Relativistic Quark Model
Energy Technology Data Exchange (ETDEWEB)
Gilberto Ramalho, Kazuo Tsushima
2011-09-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Octet baryon electromagnetic form factors in a relativistic quark model
Ramalho, G
2011-01-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Strange baryon spectroscopy in the relativistic quark model
Faustov, R N
2015-01-01
Mass spectra of strange baryons are calculated in the framework of the relativistic quark model based on the quasipotential approach. Baryons are treated as the relativistic quark-diquark bound systems. It is assumed that two quarks with equal constituent masses form a diquark. The diquark excitations and its internal structure are consistently taken into account. Calculations are performed up to rather high orbital and radial excitations of strange baryons. On this basis the Regge trajectories are constructed. The obtained results are compared with available experimental data and previous predictions. It is found that all masses of the 4- and 3-star, as well as most of the 2- and 1-star states of strange baryons with established quantum numbers are well reproduced. The developed relativistic quark-diquark model predicts less excited states than three-quark models of strange baryons.
Strange baryon spectroscopy in the relativistic quark model
Faustov, R. N.; Galkin, V. O.
2015-09-01
Mass spectra of strange baryons are calculated in the framework of the relativistic quark model based on the quasipotential approach. Baryons are treated as relativistic quark-diquark bound systems. It is assumed that two quarks with equal constituent masses form a diquark. The diquark excitations and its internal structure are consistently taken into account. Calculations are performed up to rather high orbital and radial excitations of strange baryons. On this basis the Regge trajectories are constructed. The obtained results are compared with available experimental data and previous predictions. It is found that all masses of the 4- and 3-star states of strange baryons with established quantum numbers, as well as most of the 2- and 1-star states, are well reproduced. The developed relativistic quark-diquark model predicts less excited states than three-quark models of strange baryons.
Aspects of baryon structure in lattice QCD
Babich, Ronald
Despite the long success of Quantum Chromodynamics (QCD) as the theory of the strong interactions, there remains much to be understood about the structure of hadrons and the consequences of QCD in the nonperturbative regime. Lattice gauge theory, a framework nearly as old as QCD itself, makes calculations in this regime possible, starting from first principles. With advances in theoretical understanding, methods, and computer technology, the lattice has found application to an ever-widening range of problems. In this dissertation, I consider two such problems having to do with the structure of baryons. The first concerns the contribution of sea quarks, and the strange quark in particular, to form factors of the nucleon. This has been a long-standing challenge for the lattice, because such contributions involve the insertion of a current on a quark loop, demanding the full inversion of the discretized Dirac operator, conceptually a large sparse matrix. I discuss methods for addressing this challenge and present a calculation of the strange scalar form factor and the related parameter fTs. The latter is of great theoretical interest, since it enters into the cross section for the scattering of dark matter off nuclei in supersymmetric extensions of the standard model. As such, it represents a major uncertainty in the interpretation of direct detection experiments. I also present results for the strange quark contribution to the nucleon's axial and electromagnetic form factors, which are themselves the subject of active experimental programs. These calculations were performed using the Wilson fermion formulation on a 243 x 64 anisotropic lattice. In the second part of the dissertation, I turn to the valence sector and address the role of diquark correlations in the observed spectrum of hadrons and their properties. A diquark is a correlated pair of quarks, thought to play an important role in certain phenomenological models of hadrons. I present results for baryon wave
Hyperon Single-Particle Potentials Calculated from SU6 Quark-Model Baryon-Baryon Interactions
Kohno, M; Fujita, T; Nakamoto, C; Suzuki, Y
2000-01-01
Using the SU6 quark-model baryon-baryon interaction recently developed by the Kyoto-Niigata group, we calculate NN, Lambda N and Sigma N G-matrices in ordinary nuclear matter. This is the first attempt to discuss the Lambda and Sigma single-particle potentials in nuclear medium, based on the realistic quark-model potential. The Lambda potential has the depth of more than 40 MeV, which is more attractive than the value expected from the experimental data of Lambda-hypernuclei. The Sigma potential turns out to be repulsive, the origin of which is traced back to the strong Pauli repulsion in the Sigma N (I=3/2) ^3S_1 state.
Mirage in Temporal Correlation functions for Baryon-Baryon Interactions in Lattice QCD
Iritani, Takumi; Aoki, Sinya; Gongyo, Shinya; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji
2016-01-01
Single state saturation of the temporal correlation function is a key condition to extract physical observables such as energies and matrix elements of hadrons from lattice QCD simulations. A method commonly employed to check the saturation is to seek for a plateau of the observables for large Euclidean time. Identifying the plateau in the cases having nearby states, however, is non-trivial and one may even be misled by a fake plateau. Such a situation takes place typically for the system with two or more baryons. In this study, we demonstrate explicitly the danger from a possible fake plateau in the temporal correlation functions mainly for two baryons ($\\Xi\\Xi$ and $NN$), and three and four baryons ($^3{\\rm He}$ and $^4{\\rm He})$ as well, employing (2+1)-flavor lattice QCD at $m_{\\pi}=0.51$ GeV on four lattice volumes with $L=$ 2.9, 3.6, 4.3 and 5.8 fm. Caution is given for drawing conclusion on the bound $NN$, $3N$ and $4N$ systems only based on the temporal correlation functions.
Redshift uncertainties and baryonic acoustic oscillations
Chaves-Montero, Jonás; Hernández-Monteagudo, Carlos
2016-01-01
In the upcoming era of high-precision galaxy surveys, it becomes necessary to understand the impact of uncertain redshift estimators on cosmological observables. In this paper we present a detailed exploration of the galaxy clustering and baryonic acoustic oscillation (BAO) signal under the presence of redshift errors. We provide analytic expressions for how the monopole and the quadrupole of the redshift-space power spectrum (together with their covariances) are affected. Additionally, we discuss the modifications in the shape, signal to noise, and cosmological constraining power of the BAO signature. We show how and why the BAO contrast is $\\mathit{enhanced}$ with small redshift uncertainties, and explore in detail how the cosmological information is modulated by the interplay of redshift-space distortions, redshift errors, and the number density of the sample. We validate our results by comparing them with measurements from a ensemble of $N$-body simulations with $8100h^{-3}\\text{Gpc}^3$ aggregated volume....
Cluster outskirts and the missing baryons
Eckert, D.
2016-06-01
Galaxy clusters are located at the crossroads of intergalactic filaments and are still forming through the continuous merging and accretion of smaller structures from the surrounding cosmic web. Deep, wide-field X-ray studies of the outskirts of the most massive clusters bring us valuable insight into the processes leading to the growth of cosmic structures. In addition, cluster outskirts are privileged sites to search for the missing baryons, which are thought to reside within the filaments of the cosmic web. I will present the XMM cluster outskirts project, a VLP that aims at mapping the outskirts of 13 nearby clusters. Based on the results obtained with this program, I will then explore ideas to exploit the capabilities of XMM during the next decade.
Examining CP Symmetry in Strange Baryon Decays
Luk, K B
2000-01-01
Non-conservation of CP symmetry can manisfest itself in non-leptonic hyperon decays as a difference in the decay parameter between the strange-baryon decay and its charge conjugate. By comparing the decay distribution in the $\\Lambda$ helicity frame for the decay sequence $\\Xi^{-} \\to \\Lambda \\pi^{-}$, $\\Lambda \\to p \\pi^{-}$ with that of $\\bar{\\Xi}^{+}$ decay, E756 at Fermilab did not observe any CP-odd effect at the $10^{-2}$ level. The status of a follow-up experiment, HyperCP (FNAL E871), to search for CP violation in charged $\\Xi-\\Lambda$ decay with a sensitivity of $10^{-4}$ is also presented.
Leptogenesis and gravity: Baryon asymmetry without decays
McDonald, J. I.; Shore, G. M.
2017-03-01
A popular class of theories attributes the matter-antimatter asymmetry of the Universe to CP-violating decays of super-heavy BSM particles in the Early Universe. Recently, we discovered a new source of leptogenesis in these models, namely that the same Yukawa phases which provide the CP violation for decays, combined with curved-spacetime loop effects, lead to an entirely new gravitational mechanism for generating an asymmetry, driven by the expansion of the Universe and independent of the departure of the heavy particles from equilibrium. In this Letter, we build on previous work by analysing the full Boltzmann equation, exploring the full parameter space of the theory and studying the time-evolution of the asymmetry. Remarkably, we find regions of parameter space where decays play no part at all, and where the baryon asymmetry of the Universe is determined solely by gravitational effects.
Spin-orbit interactions between two baryons
Energy Technology Data Exchange (ETDEWEB)
Takeuchi, Sachiko [Japan College of Social Work, Kiyose, Tokyo (Japan); Morimatsu, Osamu [High Energy Accelerator Research Organization, Tanashi Branch (KEK-Tanashi), Tanashi, Tokyo (Japan); Tani, Yoshihiro; Oka, Makoto [Tokyo Inst. of Tech. (Japan). Dept. of Physics
2000-04-01
The spin-orbit interactions in the quark cluster models are reviewed in this article. The observed spin-orbit force between two nucleons is strong, while that in the excited baryons or in the {lambda}N interaction is small. We try to sort out whether the quark cluster model can produce a spin-orbit force which explains these features simultaneously. Various works which include the spin-orbit force with different origins such as gluons, mesons, or coupling to other channels are compared to each other. The roles of the symmetric and anti-symmetric spin- orbit forces in the NN scattering phase shifts and in the YN low-energy cross sections and the phase shifts are investigated. (author)
On light baryons and their excitations
Eichmann, Gernot; Sanchis-Alepuz, Helios
2016-01-01
We study ground states and excitations of light octet and decuplet baryons within the framework of Dyson-Schwinger and Faddeev equations. We improve upon similar approaches by explicitly taking into account the momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. We perform calculations in both the three-body Faddeev framework and the quark-diquark approximation in order to assess the impact of the latter on the spectrum. Our results indicate that both approaches agree well with each other. The resulting spectra furthermore agree one-to-one with experiment, provided well-known deficiencies of the rainbow-ladder approximation are compensated for. We also discuss the mass evolution of the Roper and the excited Delta with varying pion mass and analyse the internal structure in terms of their partial wave decompositions.
How do galaxies get their baryons?
Conselice, Christopher J
2011-01-01
Understanding how galaxies obtain baryons, their stars and gas, over cosmic time is traditionally approached in two different ways - theoretically and observationally. In general, observational approaches to galaxy formation include measuring basic galaxy properties, such as luminosities, stellar masses, rotation speeds, star formation rates and how these features evolve through time. Theoretically, cosmologically based models collate the physical effects driving galaxy assembly - mergers of galaxies, accretion of gas, star formation, and feedback, amongst others, to form predictions which are matched to galaxy observables. An alternative approach is to examine directly, in an observational way, the processes driving galaxy assembly, including the effects of feedback. This is a new `third way' towards understanding how galaxies are forming from gas accretion and mergers, and directly probes these effects instead of relying on simulations designed to reproduce observations. This empirical approach towards unde...
Observation of excited $\\Lambda^0_b$ baryons
Aaij, R; Adametz, A; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Beddow, J; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Corti, G; Couturier, B; Cowan, G A; Craik, D; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Esperante Pereira, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauld, R; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Harrison, P F; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hoballah, M; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li, Y; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; von Loeben, J; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Luisier, J; Mac Raighne, A; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McCarthy, J; McGregor, G; McNulty, R; Meissner, M; Merk, M; Merkel, J; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen-Mau, C; Nicol, M; Niess, V; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B K; Palacios, J; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilař, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rosello, M; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schleich, S; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Vesterinen, M; Viaud, B; Videau, I; Vieira, D; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zvyagin, A
2012-01-01
Using $pp$ collision data corresponding to 1.0~fb^{-1} integrated luminosity collected by the LHCb detector, two narrow states are observed in the $\\Lambda_b^0\\pi^+\\pi^-$ spectrum with masses $5911.95\\pm 0.12(\\mbox{stat})\\pm 0.03(\\mbox{syst})\\pm 0.66(\\Lambda_b^0\\mbox{ mass})$ MeV/$c^2$ and $5919.76\\pm 0.07(\\mbox{stat})\\pm 0.02(\\mbox{syst})\\pm 0.66(\\Lambda_b^0\\mbox{ mass})$ MeV/$c^2$. The significances of the observations are 4.9 and 10.1 standard deviations, respectively. These states are interpreted as the orbitally-excited $\\Lambda_b^0$ baryons, $\\Lambda_b^{*0}(5912)$ and $\\Lambda_b^{*0}(5920)$.
Observation of a new charmed baryon
Albrecht, H.; Ehrlichmann, H.; Hamacher, T.; Hofmann, R. P.; Kirchhoff, T.; Nau, A.; Nowak, S.; Schröder, H.; Schulz, H. D.; Walter, M.; Wurth, R.; Hast, C.; Kapitza, H.; Kolanoski, H.; Kosche, A.; Lange, A.; Lindner, A.; Mankel, R.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Töpfer, D.; Wegener, D.; Bittner, M.; Eckstein, P.; Paulini, M.; Reim, K.; Wegener, H.; Eckmann, R.; Mundt, R.; Oest, T.; Reiner, R.; Schmidt-Parzefall, W.; Stiewe, J.; Werner, S.; Ehret, K.; Hofmann, W.; Hüpper, A.; Khan, S.; Knöpfle, K. T.; Seeger, M.; Spengler, J.; Britton, D. I.; Charlesworth, C. E. K.; Edwards, K. W.; Hyatt, E. R. F.; 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.; Reβing, D.; Schmidtler, M.; Schneider, M.; Schubert, K. R.; Strahl, K.; Waldi, R.; Weseler, S.; Kernel, G.; Križan, P.; Križnič, E.; Podobnik, T.; Živko, T.; Balagura, V.; Belyaev, I.; Chechelnitsky, S.; Danilov, M.; Droutskoy, A.; Gershtein, Yu.; Golutvin, A.; Korolko, I.; Kostina, G.; Litvintsev, D.; Lubimov, V.; Pakhlov, P.; Semenov, S.; Snizhko, A.; Tichomirov, I.; Zaitsev, Yu.; Argus Collaboration
1993-11-01
Using the ARGUS detector at the e+e- storage ring DORIS II at DESY, we have observed a new charmed baryon state in the channel Λc+π+π-. (All references to a specific charged state also imply the charge conjugate state.) The mass of this state was measured to be (2626.6 ± 0.5 ± 1.5) MeV/ c2. The product of the production cross section and branching ratio for this channel was determined to be (11.5 ± 2.5 ± 3.0) pb, and the natural width estimated to be smaller than 3.2 MeV/ c2 at 90% CL.
Quantum Operator Design for Lattice Baryon Spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Lichtl, Adam [Carnegie Mellon Univ., Pittsburgh, PA (United States)
2006-09-07
A previously-proposed method of constructing spatially-extended gauge-invariant three-quark operators for use in Monte Carlo lattice QCD calculations is tested, and a methodology for using these operators to extract the energies of a large number of baryon states is developed. This work is part of a long-term project undertaken by the Lattice Hadron Physics Collaboration to carry out a first-principles calculation of the low-lying spectrum of QCD. The operators are assemblages of smeared and gauge-covariantly-displaced quark fields having a definite flavor structure. The importance of using smeared fields is dramatically demonstrated. It is found that quark field smearing greatly reduces the couplings to the unwanted high-lying short-wavelength modes, while gauge field smearing drastically reduces the statistical noise in the extended operators.
First observation of doubly charmed baryons
Energy Technology Data Exchange (ETDEWEB)
M. A. Moinester et al.
2003-09-25
The SELEX experiment (E781) at Fermilab has observed two statistically compelling high mass states near 3.6 GeV/c{sup 2}, decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +} and {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}. These final states are Cabibbo-allowed decay modes of doubly charmed baryons {Xi}{sub cc}{sup +} and {Xi}{sub cc}{sup ++}, respectively. The masses are in the range expected from theoretical considerations, but the spectroscopy is surprising. SELEX also has weaker preliminary evidence for a state near 3.8 GeV/c{sup 2}, a high mass state decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}, possibly an excited {Xi}{sub cc}{sup ++} (ccu*). Data are presented and discussed.
Troyan, Yu A; Troyan, A Yu; Plekhanov, E B; Jerusalimov, A P; Piskaleva, G B; Arakelian, S G
2004-01-01
The production and properties of the resonances with the strangeness S=+1 in the system nK^{+} were studied in the reaction np\\to npK^{+}K^{-} at the momentum of incident neutrons P_{n}=(5.20\\pm 0.12) GeV/c. A number of peculiarities were found in the effective mass spectrum of the mentioned above system. All these resonances have a large statistical significance. Then widths are comparable with the mass resolution. The estimation of the spins of resonances was carried out and the rotational band connecting the resonance masses with spins was constructed
Troyan, Yu A; Troyan, Yu A; Plekhanov, E B; Jerusalimov, A P; Piskaleva, G B; Arakelian, S G; Troyan, Yu.A.
2004-01-01
The production and properties of the resonances with the strangeness S = +1 in the system of nK+ were studied in the reaction np -> npK+K- at the momentum of incident neutrons Pn = (5.20+/-0.12)GeV/c. A number of peculiarities was found in the effective mass spectrum of the mentioned above system. All these resonances have a large statistical significance. Their widths are comparable with the mass resolution. The estimation of the resonances spin was carried out and the rotational band connecting the resonances masses and their spins was constructed.
Relativistic five-quark equations and hybrid baryon spectroscopy
Gerasyuta, S M
2002-01-01
The relativistic five-quark equations are found in the framework of the dispersion relation technique. The Behavior of the low-energy five-particle amplitude is determined by its leading singularities in the pair invariant masses. The solutions of these equations using the method based on the extraction leading singularities of the amplitudes are obtained. The mass spectra of nucleon and delta-isobar hybrid baryons are calculated. The calculations of hybrid baryon amplitudes estimate the contributions of four subamplitudes. The main contributions to the hybrid baryon amplitude are determined by the subamplitudes, which include the excited gluon states.
Dark Matter and the Baryon Asymmetry of the Universe
Farrar, G R; Farrar, Glennys R.; Zaharijas, Gabrijela
2004-01-01
We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\gsi 10%$, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$.
Medium modifications of baryon properties in nuclear matter and hypernuclei
Liang, J S
2013-01-01
We study the medium modifications of baryon properties in nuclear many-body systems, especially in $\\Lambda$ hypernuclei. The nucleon and the $\\Lambda$ hyperon are described in the Friedberg-Lee model as nontopological solitons which interact through the self-consistent exchange of scalar and vector mesons. The quark degrees of freedom are explicitly considered in the model, so that the medium effects on baryons could be investigated. It is found that the model can provide reasonable descriptions for nuclear matter, finite nuclei, and $\\Lambda$ hypernuclei. The present model predicts a significant increase of the baryon radius in nuclear medium.
Missing Baryons and the Warm-Hot Intergalactic Medium
Nicastro, F; Elvis, Martin
2007-01-01
Stars and gas in galaxies, hot intracluster medium, and intergalactic photo-ionized gas make up at most half of the baryons that are expected to be present in the universe. The majority of baryons are still missing and are expected to be hidden in a web of warm-hot intergalactic medium. This matter was shock-heated during the collapse of density perturbations that led to the formation of the relaxed structures that we see today. Finding the missing baryons and thereby producing a complete inventory of possibly the only detectable component of the energy-mass budget of the universe is crucial to validate or invalidate our standard cosmological model.
Are narrow mesons, baryons and dibaryons evidence for multiquark states?
Energy Technology Data Exchange (ETDEWEB)
Tatischeff, B.; Yonnet, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire
2000-07-01
Several narrow structures have been progressively observed since the last fifteen years, in di-baryonic invariant mass spectra or in missing mass spectra. More recently, narrow structures were observed in baryonic and now in mesonic mass spectra. Since these small peaks appear at fixed masses, independently of the experiment, they are associated with real states. There is no room to explain these states within classical nuclear physics taking into account baryonic and mesonic degrees of freedom. An interpretation is proposed, which associate these narrow structures with two coloured quark clusters. (authors)
Stability issues with baryons in AdS/CFT
Sfetsos, Konstadinos
2008-01-01
We consider baryon vertices within the gauge/gravity correspondence for a class of curved backgrounds. The holographic description based on the N=4 SYM theory for SU(N) allows classical solutions representing bound states of k-quarks with k less than or equal to N. We construct the corresponding classical configurations and perform a stability analysis. We present the details for the theory at the conformal point and at finite temperature and show that there is a critical value of k, below which there is instability. This may also arise when the baryon reaches a critical size. We also extend our treatment to magnetically charged baryon vertices.
Baryons and Low-Density Baryonic Matter in 1+1 Dimensional Large N_c QCD with Heavy Quarks
Adhikari, Prabal; Jamgochian, Arec; Kumar, Nilay
2012-01-01
This paper studies baryons and baryonic matter in the combined large N_c and heavy quark mass limits of QCD in 1+1 dimension. In this non-relativistic limit, baryons are composed of N_c quarks that interact, at leading order in N_c, through a color Coulomb potential. Using variational techniques, very accurate calculations of single baryon masses and interaction energies of low-density baryon crystal are performed. These results are used to cross-check a general numerical approach applicable for arbitrary quark masses and baryon densities recently proposed by Bringoltz, which is based on a lattice in a finite box with periodic boundary conditions. The Bringoltz method differs from a previous approach of Salcedo, et al. in its treatment of a finite box effect - namely gauge configurations that wind around the box. One might expect these effects to be small for large enough boxes, in which the baryon density approaches zero to high accuracy at the edges. However, the effects of these windings appear to be quite...
Recent Developments in Chiral Unitary Dynamics of Resonances
Oset, E; Gamermann, D; Vacas, M J Vicente; Strottman, D; Khemchandani, K P; Torres, A Martinez; Oller, J A; Roca, L
2007-01-01
In this talk I summarize recent findings made on the description of axial vector mesons as dynamically generated states from the interaction of peseudoscalar mesons and vector mesons, dedicating some attention to the two $K_1(1270)$ states. Then I review the generation of open and hidden charm scalar and axial states. Finally, I present recent results showing that the low lying $1/2^+$ baryon resonances for S=-1 can be obtained as bound states or resonances of two mesons and one baryon in coupled channels dynamics.
Mass spectra and Regge trajectories of , , and baryons
Shah, Zalak; Thakkar, Kaushal; Rai, Ajay Kumar; Vinodkumar, P. C.
2016-12-01
We calculate the mass spectra of the singly charmed baryons (, , and ) using the hypercentral constituent quark model (hCQM). The hyper color Coulomb plus linear potential is used to calculate the masses of positive (up to ) and negative (up to ) parity excited states. The spin-spin, spin-orbital and tensor interaction terms are also incorporated for mass spectra. We have compared our results with other theoretical and lattice QCD predictions for each baryon. Moreover, the known experimental results are also reasonably close to our predicted masses. By using the radial and orbital excitation, we construct Regge trajectories for the baryons in the (n, M2) plane and find their slopes and intercepts. Other properties of these baryons, like magnetic moments, radiative transitions and radiative decay widths, are also calculated successfully. Supported in part (A. K. Rai) by DST, India (SERB Fast Track Scheme SR/FTP/PS-152/2012)
Dirac's Covariant Constraint Dynamics Applied to the Baryon Spectrum
Whitney, Joshua; Crater, Horace
2010-02-01
A baryon is a hadron containing three quarks in a combination of up, down, strange, charm, or bottom. For prediction of the baryon energy spectrum, a baryon is modeled as a three-body system with the interacting forces coming from a set of two-body potentials that depend on the distance between the quarks, the spin-spin and spin-orbit angular momentum coupling terms, and a tensor term. Techniques and equations are derived from Todorov's work on constraint dynamics and the quasi-potential equation together with Two Body Dirac equations developed by Crater and Van Alstine, and adapted to this specific problem by further use of Sazdjian's N-body constraints dynamics for general confined systems. Baryon spectroscopy results are presented and compared with experiment. Typically, a best fit method is used in the analyses that employ several different algorithms, including a gradient approach, Monte Carlo modeling, and simulated annealing methods. )
Baryon production in $e^{+}e^{-}$-annihilation at PETRA
Bartel, Wulfrin; Dittmann, P; Eichler, R; Felst, R; Haidt, Dieter; Krehbiel, H; Meier, K; Naroska, Beate; O'Neill, L H; Steffen, P; Wenninger, Horst; Zhang, Y; Elsen, E E; Helm, M; Petersen, A; Warming, P; Weber, G; Bethke, Siegfried; Drumm, H; Heintze, J; Heinzelmann, G; Hellenbrand, K H; Heuer, R D; Von Krogh, J; Lennert, P; Kawabata, S; Matsumura, H; Nozaki, T; Olsson, J; Rieseberg, H; Wagner, A; Bell, A; Foster, F; Hughes, G; Wriedt, H; Allison, J; Ball, A H; Bamford, G; Barlow, R; Bowdery, C K; Duerdoth, I P; Hassard, J F; King, B T; Loebinger, F K; MacBeth, A A; McCann, H; Mills, H E; Murphy, P G; Prosper, H B; Stephens, K; Clarke, D; Goddard, M C; Marshall, R; Pearce, G F; Kobayashi, T; Komamiya, S; Koshiba, M; Minowa, M; Nozaki, M; Orito, S; Sato, A; Suda, T; Takeda, H; Totsuka, Y; Watanabe, Y; Yamada, S; Yanagisawa, C
1981-01-01
Data on p and Lambda production by e/sup +/e/sup -/-annihilation at CM energies between 30 and 36 GeV are presented. Indication for an angular anticorrelation in events with baryon-antibaryon pairs is seen.
Two-Baryon Correlation Functions in 2-flavour QCD
Francis, Anthony; Rae, Thomas D; Wittig, Hartmut
2013-01-01
We present first results for two-baryon correlation functions, computed using $N_f=2$ flavours of O($a$) improved Wilson quarks, with the aim of explaining potential dibaryon bound states, specifically the H-dibaryon. In particular, we use a GEVP to isolate the groundstate using two-baryon (hyperon-hyperon) correlation functions $\\big(\\langle C_{XY}(t)C_{XY}(0) \\rangle$, where $XY=\\Lambda\\Lambda, \\Sigma\\Sigma, N\\Xi, \\cdots\\big)$, each of which has an overlap with the H-dibaryon. We employ a `blocking' algorithm to handle the large number of contractions, which may easily be extended to N-baryon correlation functions. We also comment on its application to the analysis of single baryon masses ($n$, $\\Lambda$, $\\Xi$, $\\cdots$). This study is performed on an isotropic lattice with $m_\\pi = 460$ MeV, $m_\\pi L = 4.7$ and $a = 0.063$ fm.
Chiral Dynamics of Baryons in a Lorentz Covariant Quark Model
Faessler, A; Lyubovitskij, V E; Pumsa-ard, K; Faessler, Amand; Gutsche, Th.
2006-01-01
We develop a manifestly Lorentz covariant chiral quark model for the study of baryons as bound states of constituent quarks dressed by a cloud of pseudoscalar mesons. The approach is based on a non-linear chirally symmetric Lagrangian, which involves effective degrees of freedom - constituent quarks and the chiral (pseudoscalar meson) fields. In a first step, this Lagrangian can be used to perform a dressing of the constituent quarks by a cloud of light pseudoscalar mesons and other heavy states using the calculational technique of infrared dimensional regularization of loop diagrams. We calculate the dressed transition operators with a proper chiral expansion which are relevant for the interaction of quarks with external fields in the presence of a virtual meson cloud. In a second step, these dressed operators are used to calculate baryon matrix elements. Applications are worked out for the masses of the baryon octet, the meson-nucleon sigma terms, the magnetic moments of the baryon octet, the nucleon charge...
Electromagnetic form factors of baryons in an algebraic approach
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
1999-07-01
We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered. (Author)
Electromagnetic form factors of baryons in an algebraic approach
Bijker, R
1999-01-01
We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered.
Octet baryon electromagnetic form factors in nuclear medium
Ramalho, G; Thomas, A W
2012-01-01
We study the octet baryon electromagnetic form factors in nuclear matter using the covariant spectator quark model extended to the nuclear matter regime. The parameters of the model in vacuum are fixed by the study of the octet baryon electromagnetic form factors. In nuclear matter the changes in hadron properties are calculated by including the relevant hadron masses and the modification of the pion-baryon coupling constants calculated in the quark-meson coupling model. In nuclear matter the magnetic form factors of the octet baryons are enhanced in the low $Q^2$ region, while the electric form factors show a more rapid variation with $Q^2$. The results are compared with the modification of the bound proton electromagnetic form factors observed at Jefferson Lab. In addition, the corresponding changes for the bound neutron are predicted.
Troyan, Yu. A.; Beljaev, A. V.; Troyan, A. Yu.; Plekhanov, E. B.; Jerusalimov, A. P.; Piskaleva, G. B.; Arakelian, S. G.
2004-01-01
The production and properties of the resonances with the strangeness S = +1 in the system of nK+ were studied in the reaction np -> npK+K- at the momentum of incident neutrons Pn = (5.20+/-0.12)GeV/c. A number of peculiarities was found in the effective mass spectrum of the mentioned above system. All these resonances have a large statistical significance. Their widths are comparable with the mass resolution. The estimation of the spins of resonances was carried out and the rotational band co...
Chiral extrapolations and strangeness in the baryon ground states
Lutz, Matthias F M
2013-01-01
We review the quark-mass dependence of the baryon octet and decuplet masses as obtained from recent lattice simulations of the BMW, PACS-CS, LHPC, HSC and QCDSF-UKQCD groups. Our discussion relies on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. In our analysis the physical masses are reproduced exactly by means of a suitable set of linear constraints. A quantitative and simultaneous description of all lattice results is achieved in terms of a six parameter fit, where the symmetry conserving counter term that are relevant at N$^3$LO are not yet being used. For pion masses larger than 300 MeV there appears to be an approximate linear pion-mass dependence of all octet and decuplet baryon masses. We discuss the pion- and strangeness sigma terms of the baryon octet states.
Possible hidden-charm molecular baryons composed of an anti-charmed meson and a charmed baryon
Institute of Scientific and Technical Information of China (English)
YANG Zhong-Cheng; SUN Zhi-Feng; HE Jun; LIU Xiang; ZHU Shi-Lin
2012-01-01
Using the one-boson-exchange model,we studied the possible existence of very loosely bound hidden-charm molecular baryons composed of an anti-charmed meson and a charmed baryon.Our numerical results indicate that the ∑c(D)* and ∑c(D) states exist,but that the ∑c(D) and ∑c(D)* molecular states do not.
Heavy baryons as polarimeters at colliders
Galanti, Mario; Grossman, Yuval; Kats, Yevgeny; Stamou, Emmanuel; Zupan, Jure
2015-01-01
In new-physics processes that produce b or c jets, a measurement of the initial b or c-quark polarization could provide crucial information about the structure of new physics. In the heavy-quark limit, the b and c-quark polarizations are preserved in the lightest baryons they hadronize into, Lambda_b and Lambda_c, respectively. We revisit the prediction for the polarization retention after the hadronization process and extend it to the case of transverse polarization. We show how ATLAS and CMS can measure the b-quark polarization using semileptonic Lambda_b decays, and the c-quark polarization using Lambda_c+ -> p K- pi+ decays. For calibrating both measurements we suggest to use ttbar samples in which the polarizations can be measured with a precision of order 10% using 100/fb of data in Run 2 of the LHC. LHCb measurements of the transverse polarization in QCD events are motivated as well. An existing LHCb analysis can be significantly improved for this purpose.
BASE - The Baryon Antibaryon Symmetry Experiment
Smorra, C.; Blaum, K.; Bojtar, L.; Borchert, M.; Franke, K. A.; Higuchi, T.; Leefer, N.; Nagahama, H.; Matsuda, Y.; Mooser, A.; Niemann, M.; Ospelkaus, C.; Quint, W.; Schneider, G.; Sellner, S.; Tanaka, T.; Van Gorp, S.; Walz, J.; Yamazaki, Y.; Ulmer, S.
2015-11-01
The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a stringent test of the combined charge parity and time reversal (CPT) symmetry by comparing the magnetic moments of the proton and the antiproton with high precision. Using single particles in a Penning trap, the proton/antiproton g-factors, i.e. the magnetic moment in units of the nuclear magneton, are determined by measuring the respective ratio of the spin-precession frequency to the cyclotron frequency. The spin precession frequency is measured by non-destructive detection of spin quantum transitions using the continuous Stern-Gerlach effect, and the cyclotron frequency is determined from the particle*s motional eigenfrequencies in the Penning trap using the invariance theorem. By application of the double Penning-trap method we expect that in our measurements a fractional precision of δg/g 10-9 can be achieved. The successful application of this method to the antiproton will consist a factor 1000 improvement in the fractional precision of its magnetic moment. The BASE collaboration has constructed and commissioned a new experiment at the Antiproton Decelerator (AD) of CERN. This article describes and summarizes the physical and technical aspects of this new experiment.
First observation of a baryonic Bc+ decay.
Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cojocariu, L; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H-M; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farley, N; Farry, S; Fay, Rf; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gavardi, L; Gavrilov, G; Geraci, A; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Giani', S; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lu, H; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A
2014-10-10
A baryonic decay of the B(c)(+) meson, B(c)(+) → J/ψppπ(+), is observed for the first time, with a significance of 7.3 standard deviations, in pp collision data collected with the LHCb detector and corresponding to an integrated luminosity of 3.0 fb(-1) taken at center-of-mass energies of 7 and 8 TeV. With the B(c)(+) → J/ψπ(+) decay as the normalization channel, the ratio of branching fractions is measured to be B(B(c)(+) → J/ψppπ(+))/B(B(c)(+) → J/ψπ(+)) = 0.143(-0.034)(+0.039)(stat) ± 0.013(syst). The mass of the B(c)(+) meson is determined as M(B(c)(+) = 6274.0 ± 1.8(stat) ± 0.4(syst) MeV/c(2), using the B(c)(+) → J/ψppπ(+) channel.
The Photon-Baryon Governed Universe
Directory of Open Access Journals (Sweden)
Laszlo A. Marosi
2012-01-01
Full Text Available In a previous paper we postulated that the repulsive force responsible for the universal expansion is associated with the excitation of the empty space (quantum vacuum and the excitation energy is represented by the energy of the cosmic microwave background (CMB. In this paper, we show that the concept of the repulsive space expanding photon field (i can successfully be applied to explain the local velocity anomaly of the Milky Way Galaxy as shown by Faber and Burstein (1998 and Tully (1998, (ii offers a convincing explanation of the still disputed question of the cosmological expansion on local and intergalactic scales discussed by Cooperstock et al. (1998, and (iii explains the redshift (RS of the CMB in accordance with the law of energy conservation without the need for dark matter (DM and dark energy (DE. Probably the most remarkable result of this model (abbreviated as photon/baryon: PB model in the following discussion is that the individual voids building up the soup-bubble- (SB- like galaxy distribution are the governing dynamical components of the universal expansion. Further consequence implies that the universe is considerably older than the interpretation of the Hubble constant as expansion velocity suggests.
Baryon Acoustic Oscillations reconstruction with pixels
Obuljen, Andrej; Castorina, Emanuele; Viel, Matteo
2016-01-01
Gravitational non-linear evolution induces a shift in the position of the baryon acoustic oscillations (BAO) peak together with a damping and broadening of its shape that bias and degrades the accuracy with which the position of the peak can be determined. BAO reconstruction is a technique developed to undo part of the effect of non-linearities. We present a new reconstruction method that consists in displacing pixels instead of galaxies and whose implementation is easier than the standard reconstruction method. We show that our method is equivalent to the standard reconstruction technique in the limit where the number of pixels becomes very large. This method is particularly useful in surveys where individual galaxies are not resolved, as in 21cm intensity mapping observations. We validate our method by reconstructing mock pixelated maps, that we build from the distribution of matter and halos in real- and redshift-space, from a large set of numerical simulations. We find that our method is able to decrease ...
Structure and reactions of pentaquark baryons
Indian Academy of Sciences (India)
Atsushi Hosaka
2006-04-01
We review the current status of the exotic pentaquark baryons. After a brief look at experiments of both positive and negative results, we discuss theoretical methods to study the structure and reactions for the pentaquarks. First we introduce the quark model and the chiral soliton model, where we discuss the relation of mass spectrum and parity with some emphasis on the role of chiral symmetry. It is always useful to picture the structure of the pentaquarks in terms of quarks. As for other methods, we discuss a model-independent method, and briefly mention the results from the lattice and QCD sum rule. Decay properties are then studied in some detail, which is one of the important properties of +. We investigate the relation between the decay width and the quark structure having certain spin-parity quantum numbers. Through these analyses, we consider as plausible quantum numbers of +, = 3/2-. In the last part of this note, we discuss production reactions of + which provide links between the theoretical models and experimental information. We discuss photoproductions and hadron-induced reactions which are useful to explore the nature of +.
BASE - The Baryon Antibaryon Symmetry Experiment
Smorra, C; Bojtar, L.; Borchert, M.; Franke, K.A.; Higuchi, T.; Leefer, N.; Nagahama, H.; Matsuda, Y.; Mooser, A.; Niemann, M.; Ospelkaus, C.; Quint, W.; Schneider, G.; Sellner, S.; Tanaka, T.; Van Gorp, S.; Walz, J.; Yamazaki, Y.; Ulmer, S.
2015-01-01
The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a stringent test of the combined charge parity and time reversal (CPT) symmetry by comparing the magnetic moments of the proton and the antiproton with high precision. Using single particles in a Penning trap, the proton/antiproton $g$-factors, i.e. the magnetic moment in units of the nuclear magneton, are determined by measuring the respective ratio of the spin-precession frequency to the cyclotron frequency. The spin precession frequency is measured by non-destructive detection of spin quantum transitions using the continuous Stern-Gerlach effect, and the cyclotron frequency is determined from the particle's motional eigenfrequencies in the Penning trap using the invariance theorem. By application of the double Penning-trap method we expect that in our measurements a fractional precision of $\\delta g/g$ 10$^{-9}$ can be achieved. The successful application of this method to the antiproton will represent a factor 1000 improvement in the frac...
Missing strange resonances in Lattice QCD
Marczenko, Michał
2016-01-01
Recent Lattice QCD (LQCD) studies suggest that there are missing resonances in the strange sector of the Hadron Resonance Gas (HRG) model. By adopting the continuous Hagedorn mass spectrum, we present how different medium compositions influence the HRG predictions of conserved charge fluctuations. It is shown that missing strange resonances may be partially accounted for by applying the Hagedorn mass spectrum extracted from experimentally established hadrons. On the other hand, the strange-baryonic spectra, extracted from LQCD results for fluctuations, are found to be consistent with the unconfirmed states in the Particle Data Group (PDG) database, whilst the strange-mesonic spectrum points towards yet undiscovered states in the intermediate mass region.
Instructive discussion of effective block algorithm for baryon-baryon correlators
Nemura, Hidekatsu
2015-01-01
We describe a fairly specific idea to calculate efficiently a large number of four-point correlation functions, which are primary quantities to study the nuclear force and hyperonic nuclear forces from lattice QCD, for various baryon-baryon (BB) channels. We discuss how the effective block algorithm significantly reduces the number of iterations with considering the four-point correlator of proton-$\\Lambda$ system as a specific example. The effective block algorithm is applied to calculate the 52 channels of four-point correlation functions from nucleon-nucleon to $\\Xi-\\Xi$, in order to study the complete set of isospin symmetric BB interactions. The elapsed times measured on hybrid parallel computation on BlueGene/Q show reasonable performances at various combinations of the number of OpenMP threads and the number of MPI nodes. The numerical results are benchmarked with the results from the unified contraction algorithm for all of computed sites of 52 four-point correlators.
Instructive discussion of an effective block algorithm for baryon-baryon correlators
Nemura, Hidekatsu
2016-10-01
We describe an approach for the efficient calculation of a large number of four-point correlation functions for various baryon-baryon (BB) channels, which are the primary quantities for studying the nuclear and hyperonic nuclear forces from lattice quantum chromodynamics. Using the four-point correlation function of a proton- Λ system as a specific example, we discuss how an effective block algorithm significantly reduces the number of iterations. The effective block algorithm is applied to calculate 52 channels of the four-point correlation functions from nucleon-nucleon to Ξ- Ξ, in order to study the complete set of isospin symmetric BB interactions. The elapsed times measured for hybrid parallel computation on BlueGene/Q demonstrate that the performance of the present algorithm is reasonable for various combinations of the number of OpenMP threads and the number of MPI nodes. The numerical results are compared with the results obtained using the unified contraction algorithm for all computed sites of the 52 four-point correlators.
New Forces and the 750 GeV Resonance
Duerr, Michael; Smirnov, Juri
2016-01-01
Recently, the ATLAS and CMS collaborations have pointed out the possible existence of a new resonance with a mass around 750 GeV. We investigate the possibility to identify this new resonance with a spin zero field responsible for the breaking of a new gauge symmetry. We focus on a simple theory where the baryon number is a local symmetry spontaneously broken at the low scale. In this context new vector-like quarks are needed to cancel all baryonic anomalies and define the production mechanism and decays of the new Higgs at the LHC. Assuming the existence of the new Higgs with a mass of 750 GeV at the LHC we find an upper bound on the symmetry breaking scale. Therefore, one expects that a new force associated with baryon number could be discovered at the LHC.
Ghosh, Sabyasachi
2016-01-01
Electromagnetic current-current correlators in pionic and nucleonic medium have been evaluated in the static limit to obtain electrical conductivities for pion and nucleon components respectively, where former decreases and latter one increases with the variation of temperature $T$ and baryon chemical potential $\\mu_N$. Therefore, total electrical conductivity of pion and nucleon system exhibits a valley structure in the $T$-$\\mu_N$ plane. To get non-divergent and finite values of correlators, finite thermal widths of medium constituents, pion and nucleon have been considered, where these thermal widths have been determined from the in-medium scattering probabilities of pion and nucleon with other mesonic and baryonic resonances, based on effective hadronic model. At $\\mu_N=0$, the results of present work are more or less agrees with the results of earlier works and its finite $\\mu_N$ extension show a decreasing nature of electrical conductivity for hadronic medium during spanning from freeze out line to quar...
Baryon exchange reactions in. pi. -p scattering at 4 GeV/c. [Differential cross sections
Energy Technology Data Exchange (ETDEWEB)
Scharre, D.L.
1977-04-01
An experiment designed to study baryon exchange reactions in ..pi../sup -/p scattering at 4 GeV/c is discussed. The experiment was performed at the Bevatron and utilized a streamer chamber and a downstream spectrometer which consisted of two scintillation counter hodoscopes and a Cerenkov counter to define the fast proton trigger, and two planes of spark chambers to provide improved resolution on the forward track. Analysis of meson production in the reactions ..pi../sup -/p ..-->.. pM/sup -/, ..pi../sup -/p ..-->.. p..pi../sup -/M/sup 0/, ..pi../sup -/p ..-->.. Lambda/sup 0/M/sup 0/ is discussed for backward production of meson systems M/sup -/ and M/sup 0/. Differential cross sections and decay distributions (where applicable) for ..pi../sup -/, rho/sup -/, rho/sup 0/, f/sup 0/, omega/sup 0/, eta/sup 0/, and K*/sup 0/ production are discussed. Upper limits for A/sup -//sub 1/, A/sup -//sub 2/, and B/sup -/ production are given. Baryon resonance production and limits on exotic meson production are briefly discussed.
Search for non-strange exotic mesons produced via baryon exchange
Boucrot, J; Bouquet, B; D'Almagne, B; De Rosny, G; Ferrer, A; Jacholkowski, A; Lahellec, A; Navach, F; Petroff, P; Rivet, P; Roudeau, P; Rougé, A; Salmeron, Roberto Aureliano; Six, J; Sonderegger, P; Treille, D; Volte, A; Wuthrick, J P; Yoshida, H
1977-01-01
Negative results on backward production via baryon exchange, of exotic non-strange mesons are presented. The reactions pi /sup -/p to p/sub forward/X/sup -/ and pi /sup -/n to p/sub forward/X/sup --/ have been studied with a 12 GeV/c pi /sup -/ beam in the Omega spectrometer at CERN. No resonant peak in X to pp pi /sup -/, pp pi /sup -/ pi /sup - /, pp pi /sup -/ pi /sup 0/, pi /sup +/ pi /sup -/ pi /sup -/ pi /sup -/, pi /sup +/ pi /sup -/ pi /sup -/ pi /sup 0/ has been seen. The upper limits obtained on cross sections for exotic meson production X to NN pi , NN pi pi , 4 pi are lower than the rho /sup -/ backward production cross section in the pi /sup -/p to p rho /sup -/ reaction; this result seems to contradict the predictions of the two-component duality model. Compared with already published experiments in the search for exotics produced via baryon exchange, the sensitivity of this experiment is higher by an order of magnitude. (20 refs).
First Observation of Heavy Baryons \\Sigma_b and \\Sigma_b^*
Aaltonen, T; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bölla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, Yu A; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, 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; Crescioli, F; Cuenca-Almenar, C; Cuevas-Maestro, J; Culbertson, R; Cully, J C; Da Ronco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; De Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, Mauro; Delli Paoli, F; 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; Dorr, C; 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, I; Fedorko, W T; Feild, R G; Feindt, M; Fernández, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; García, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gómez, G; Gómez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimarães 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; Hidas, D; Hill, C S; Hirschbuehl, D; Höcker, A; Holloway, 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; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; 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; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; 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; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; 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; Makhoul, K; Mäki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martinez-Ballarin, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtälä, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla-Fernández, P A; Mülmenstädt, J; Mukherjee, A; Müller, T; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Österberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, Aldo L; 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; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P B; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Salto, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; 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; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T G; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakian, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Söderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Saint-Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; Van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobuev, I P; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; 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; Zhou, J; Zucchelli, S
2007-01-01
We report an observation of new bottom baryons produced in proton-antiproton collisions at the Tevatron. Using 1.1 fb^{-1} of data collected by the CDF II detector, we observe four \\Lambda_b^0\\pi^{\\pm} resonances in the fully reconstructed decay mode \\Lambda_b^0 \\to \\Lambda_c^+ \\pi^-, where \\Lambda_c^+ \\to p K^- \\pi^+. We interpret these states as the \\Sigma_b^{(*)\\pm} baryons and measure their masses to be: m_{\\Sigma_b^+} = 5807.8^{+2.0}_{-2.2} (stat.) \\pm 1.7 (syst.) MeV/c^2 m_{\\Sigma_b^-} = 5815.2 \\pm 1.0 (stat.) \\pm 1.7 (syst.) MeV/c^2 m_{\\Sigma_b^{*+}} = 5829.0^{+1.6}_{-1.8} (stat.) ^{+1.7}_{-1.8} (syst.) MeV/c^2 m_{\\Sigma_b^{*-}} = 5836.4 \\pm 2.0 (stat.) ^{+1.8}_{-1.7} (syst.) MeV/c^2
Baryon states with hidden charm in the extended local hidden gauge approach
Energy Technology Data Exchange (ETDEWEB)
Uchino, T.; Oset, E. [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Valencia (Spain); Liang, Wei-Hong [Guangxi Normal University, Department of Physics, Guilin (China)
2016-03-15
The s-wave interaction of anti DΛ{sub c}, anti DΣ{sub c}, anti D{sup *}Λ{sub c}, anti D{sup *}Σ{sub c} and anti DΣ{sub c}{sup *}, anti D{sup *}Σ{sub c}{sup *}, is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two of anti DΣ{sub c} - anti D{sup *}Σ{sub c} with J = 1/2, and two of anti DΣ{sub c}{sup *} - anti D{sup *}Σ{sub c}{sup *} with J = 3/2. Moreover, we find a anti D{sup *}Σ{sub c} resonance which couples to the anti DΛ{sub c} channel and one spin degenerated bound state of anti D{sup *}Σ{sub c}{sup *} with J = 1/2,5/2. (orig.)
Structure of charmed baryons studied by pionic decays
Nagahiro, Hideko; Hosaka, Atsushi; Oka, Makoto; Noumi, Hiroyuki
2016-01-01
We investigate the decays of the charmed baryons aiming at the systematic understanding of hadron internal structures based on the quark model by paying attention to heavy quark symmetry. We evaluate the decay widths from the one pion emission for the known excited states, \\Lambda_c^*(2595), \\Lambda_c^*(2625), \\Lambda_c^*(2765), \\Lambda_c^*(2880) and \\Lambda_c^*(2940), as well as for the ground states \\Sigma_c(2455) and \\Sigma_c^*(2520). The decay properties of the lower excited charmed baryons are well explained, and several important predictions for higher excited baryons are given. We find that the axial-vector type coupling of the pion to the light quarks is essential, which is expected from chiral symmetry, to reproduce the decay widths especially of the low lying \\Lambda_c^* baryons. We emphasize the importance of the branching ratios of \\Gamma(\\Sigma_c^*\\pi)/\\Gamma(\\Sigma_c\\pi) for the study of the nature of higher excited \\Lambda_c^* baryons.
Propagation of heavy baryons in heavy-ion collisions
Das, Santosh K.; Torres-Rincon, Juan M.; Tolos, Laura; Minissale, Vincenzo; Scardina, Francesco; Greco, Vincenzo
2016-12-01
The drag and diffusion coefficients of heavy baryons (Λc and Λb ) in the hadronic phase created in the latter stage of the heavy-ion collisions at RHIC and LHC energies have been evaluated recently. In this work we compute some experimental observables, such as the nuclear suppression factor RA A and the elliptic flow v2 of heavy baryons at RHIC and LHC energies, highlighting the role of the hadronic phase contribution to these observables, which are going to be measured at Run 3 of LHC. For the time evolution of the heavy quarks in the quark and gluon plasma (QGP) and heavy baryons in the hadronic phase, we use the Langevin dynamics. For the hadronization of the heavy quarks to heavy baryons we employ Peterson fragmentation functions. We observe a strong suppression of both the Λc and Λb . We find that the hadronic medium has a sizable impact on the heavy-baryon elliptic flow whereas the impact of hadronic medium rescattering is almost unnoticeable on the nuclear suppression factor. We evaluate the Λc/D ratio at RHIC and LHC. We find that the Λc/D ratio remains unaffected due to the hadronic phase rescattering which enables it as a nobel probe of QGP phase dynamics along with its hadronization.
Spectroscopy of doubly charmed baryons from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Padmanath, M. [Univ. of Graz, Graz (Austria); Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mathur, Nilmani [Tata Inst. of Fundamental Research, Mumbai (India); Peardon, Michael [Trinity College, Dublin (Ireland)
2015-05-06
This study presents the ground and excited state spectra of doubly charmed baryons from lattice QCD with dynamical quark fields. Calculations are performed on anisotropic lattices of size 16³ × 128, with inverse spacing in temporal direction a_{t}⁻¹=5.67(4) GeV and with a pion mass of about 390 MeV. A large set of baryonic operators that respect the symmetries of the lattice yet which retain a memory of their continuum analogues are used. These operators transform as irreducible representations of SU(3)_{F} symmetry for flavor, SU(4) symmetry for Dirac spins of quarks and O(3) for spatial symmetry. The distillation method is utilized to generate baryon correlation functions which are analyzed using the variational fitting method to extract excited states. The lattice spectra obtained have baryonic states with well-defined total spins up to 7/2 and the pattern of low-lying states does not support the diquark picture for doubly charmed baryons. On the contrary the calculated spectra are remarkably similar to the expectations from models with an SU(6)×O(3) symmetry. Various spin-dependent energy splittings between the extracted states are also evaluated.
Another source of baryons in B meson decays
Dunietz, Isard; Falk, A F; Wise, M B; Isard Dunietz; Peter S Cooper; Adam F Falk; Mark B Wise
1994-01-01
It is usually assumed that the production of baryons in B meson decays is induced primarily by the quark level process b\\to c\\bar ud, where the charm quark hadronizes into a charmed baryon. With this assumption, the \\Lambda_c momentum spectrum would indicate that the transition B\\to\\Lambda_c X is dominated by multi-body B decays. However, a closer examination of the momentum spectrum reveals that the mass m_X against which the \\Lambda_c is recoiling almost always satisfies m_X\\agt m_{\\Xi_c}. This fact leads us to examine the hypothesis that the production of charmed baryons in B decays is in fact dominated by the underlying transition b\\to c\\bar cs, and is seen primarily in modes with two charmed baryons in the final state. We propose a number of tests of this hypothesis. If this mechanism is indeed important in baryon production, then there are interesting consequences and applications, including potentially important implications for the ``charm deficit'' in B decays.
Excited state mass spectra of singly charmed baryons
Energy Technology Data Exchange (ETDEWEB)
Shah, Zalak; Kumar Rai, Ajay [Sardar Vallabhbhai National Institute of Technology, Department of Applied Physics, Surat, Gujarat (India); Thakkar, Kaushal [GIDC Degree Engineering College, Department of Applied Sciences and Humanities, Abrama (India); Vinodkumar, P.C. [Sardar Patel University, Department of Physics, V.V. Nagar (India)
2016-10-15
Mass spectra of excited states of the singly charmed baryons are calculated using the hypercentral description of the three-body system. The baryons consist of a charm quark and light quarks (u, d and s) are studied in the framework of QCD motivated constituent quark model. The form of the confinement potential is hyper-Coloumb plus power potential with potential index ν, varying from 0.5 to 2.0. The first-order correction to the confinement potential is also incorporated in this approach. The radial as well as orbital excited state masses of Σ{sub c}{sup ++}, Σ{sub c}{sup +}, Σ{sub c}{sup 0}, Ξ{sub c}{sup +}, Ξ{sub c}{sup 0}, Λ{sub c}{sup +}, Ω{sub c}{sup 0} baryons, are reported in this paper. We have incorporated spin-spin, spin-orbit and tensor interactions perturbatively in the present study. The semi-electronic decay of Ω{sub c} and Ξ{sub c} are also calculated using the spectroscopic parameters of these baryons. The computed results are compared with other theoretical predictions as well as with the available experimental observations. We also construct the Regge trajectory in (n{sub r},M{sup 2}) and (J,M{sup 2}) planes for these baryons. (orig.)
The segregation of baryons and dark matter during halo assembly
Liao, Shihong; Frenk, Carlos S; Guo, Qi; Wang, Jie
2016-01-01
The standard galaxy formation theory assumes that baryons and dark matter are initially well-mixed before becoming segregated due to radiative cooling. We use non-radiative hydrodynamical simulations to explicitly examine this assumption and find that baryons and dark matter can also be segregated during the build-up of the halo. As a result, baryons in many haloes do not originate from the same Lagrangian region as the dark matter. When using the fraction of corresponding dark matter and gas particles in the initial conditions (the "paired fraction") as a proxy of the dark matter and gas segregation strength of a halo, on average about $25$ percent of the baryonic and dark matter of the final halo are segregated in the initial conditions. A consequence of this effect is that the baryons and dark matter of the same halo initially experience different tidal torques and thus their angular momentum vectors are often misaligned. This is at odds with the assumption of the standard galaxy formation model, and chall...
Burkert, Volker D
2016-01-01
Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and $\\Delta$ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger Equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of $Q^2 > 1.5GeV^2$. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degre...
Burkert, Volker D.
2016-10-01
Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and Δ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of Q^2 > 1.5 GeV^2. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degrees of freedom underlying the excited states and their dependence on the distance scale probed.
Towards a realistic description of hadron resonances
Schmidt, R. A.; Canton, L.; Schweiger, W.; Plessas, W.
2016-08-01
We report on our attempts of treating excited hadron states as true quantum resonances. Hitherto the spectroscopy of mesons, usually considered as quark-antiquark systems, and of baryons, usually considered as three-quark systems, has been treated through excitation spectra of bound states (namely, confined few-quark systems), corresponding to poles of the quantum-mechanical resolvent at real negative values in the complex energy plane. As a result the wave functions, i.e. the residua of the resolvent, have not exhibited the behaviour as required for hadron resonances with their multiple decay modes. This has led to disturbing shortcomings in the description of hadronic resonance phenomena. We have aimed at a more realistic description of hadron resonances within relativistic constituent-quark models taking into account explicitly meson-decay channels. The corresponding coupled-channels theory is based on a relativistically invariant mass operator capable of producing hadron ground states with real energies and hadron resonances with complex energies, the latter corresponding to poles in the lower half-plane of the unphysical sheet of the complex energy plane. So far we have demonstrated the feasibility of the coupled-channels approach to hadron resonances along model calculations producing indeed the desired properties. The corresponding spectral properties will be discussed in this contribution. More refined studies are under way towards constructing a coupled-channels relativistic constituent-quark model for meson and baryon resonances.
Study on the Baryon State X Produced in the Process J/ψ→ p+X, X → p + P
Institute of Scientific and Technical Information of China (English)
SHEN Qi-Xing; YU Hong; LI De-Min
2002-01-01
The decay process J/ψ→ p+ X, X → p+ P, where p,p and P are the proton, antiproton and pseudoscalarstates, respectively, has been studied in terms of the angular distribution and the generalized moment analysis methods.The result shows that we can identify the spin, but cannot determine the parity of the baryon resonance state X producedin the process J/ψ→ p + X, X → p + P.
Non-singlet Baryons in Less Supersymmetric Backgrounds
Giataganas, Dimitrios; Picos, Marco; Siampos, Konstadinos
2012-01-01
We analyze the holographic description of non-singlet baryons in various backgrounds with reduced supersymmetries and/or confining. We show that they exist in all AdS_5xY_5 backgrounds with Y_5 an Einstein manifold bearing five form flux, for a number of quarks 5N/8< k< N, independently on the supersymmetries preserved. This result still holds for gamma_i deformations. In the confining Maldacena-Nunez background non-singlet baryons also exist, although in this case the interval for the number of quarks is reduced as compared to the conformal case. We generalize these configurations to include a non-vanishing magnetic flux such that a complementary microscopical description can be given in terms of lower dimensional branes expanding into fuzzy baryons. This description is a first step towards exploring the finite 't Hooft coupling region.
Measurement of the Lifetime of b-baryons
Abreu, P; Adye, T; Adzic, P; Albrecht, Z; Alderweireld, T; Alekseev, G D; Alemany, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Branchini, P; Brenke, T; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camporesi, T; Canale, V; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Chapkin, M M; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cieslik, K; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crépé, S; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Fichet, S; Firestone, A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Green, C; Grimm, H J; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Hansen, J; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hughes, G J; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Kersevan, Borut P; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kinvig, A; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kriznic, E; Krstic, J; Krumshtein, Z; Kubinec, P; Kurowska, J; Kurvinen, K L; Lamsa, J; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Malychev, V; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Moch, M; Møller, R; Mönig, K; Monge, M R; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neufeld, N; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolenko, M; Nomokonov, V P; Normand, Ainsley; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rakoczy, D; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Royon, C; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schneider, H; Schwemling, P; Schwickerath, U; Schyns, M A E; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Sekulin, R L; Shellard, R C; Sheridan, A; Siebel, M; Simard, L C; Simonetto, F; Sissakian, A N; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stampfer, D; Stanescu, C; Stanic, S; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tegenfeldt, F; Terranova, F; Thomas, J; Timmermans, J; Tinti, N; Tkatchev, L G; Todorova-Nová, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Van Vulpen, I B; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Vollmer, C F; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G
1999-01-01
The average lifetime of weakly decaying $b$-baryons was studied using 3.6 million $Z^0$ hadronic decays collected by the DELPHI detector at LEP. The measurement of the proper decay time distribution of secondary vertices was used on three complementary samples. The first sample consisted of events with a fully reconstructed $\\Lambda_c^+$ and an opposite charge lepton, or an oppositely charged lepton pair accompanied by a $\\Lambda^0$. The other two samples were more inclusive, where $b$-baryon semileptonic decays were recognized by the presence of either a proton identified by the RICH detector or a $\\Lambda^0$ and a lepton of charge opposite to that of the proton. The combined result was: \\begin{eqnarray*} \\tau(b\\mathrm{-baryon}) = 1.14\\pm0.08 \\; (stat)\\pm0.04 \\; (syst) \\; \\mathrm{ps} \\; . \\end{eqnarray*} It updates and replaces all previous results published by the DELPHI collaboration.
Accurate initial conditions in mixed Dark Matter--Baryon simulations
Valkenburg, Wessel
2016-01-01
We quantify the error in the results of mixed baryon--dark-matter hydrodynamic simulations, stemming from outdated approximations for the generation of initial conditions. The error at redshift 0 in contemporary large simulations, is of the order of few to ten percent in the power spectra of baryons and dark matter, and their combined total-matter power spectrum. After describing how to properly assign initial displacements and peculiar velocities to multiple species, we review several approximations: (1) {using the total-matter power spectrum to compute displacements and peculiar velocities of both fluids}, (2) scaling the linear redshift-zero power spectrum back to the initial power spectrum using the Newtonian growth factor ignoring homogeneous radiation, (3) using longitudinal-gauge velocities with synchronous-gauge densities, and (4) ignoring the phase-difference in the Fourier modes for the offset baryon grid, relative to the dark-matter grid. Three of these approximations do not take into account that ...
Baryons as relativistic three-quark bound states
Eichmann, Gernot; Williams, Richard; Alkofer, Reinhard; Fischer, Christian S
2016-01-01
We review the spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD. The composite nature of baryons results in a rich excitation spectrum, whilst leading to highly non-trivial structural properties explored by the coupling to external (electromagnetic and other) currents. Both present many unsolved problems despite decades of experimental and theoretical research. We discuss the progress in these fields from a theoretical perspective, focusing on nonperturbative QCD as encoded in the functional approach via Dyson-Schwinger and Bethe-Salpeter equations. We give a systematic overview as to how results are obtained in this framework and explain technical connections to lattice QCD. We also discuss the mutual relations to the quark model, which still serves as a reference to distinguish 'expected' from 'unexpected' physics. We confront recent results on the spectrum of non-strange and strange baryons, their form factors and the issues of two-photon proce...
Accounting for Baryons in Cosmological Constraints from Cosmic Shear
Zentner, Andrew R; Dodelson, Scott; Eifler, Tim; Krause, Elisabeth; Hearin, Andrew P
2012-01-01
One of the most pernicious theoretical systematics facing upcoming gravitational lensing surveys is the uncertainty introduced by the effects of baryons on the power spectrum of the convergence field. One method that has been proposed to account for these effects is to allow several additional parameters (that characterize dark matter halos) to vary and to fit lensing data to these halo parameters concurrently with the standard set of cosmological parameters. We test this method. In particular, we use this technique to model convergence power spectrum predictions from a set of cosmological simulations. We estimate biases in dark energy equation of state parameters that would be incurred if one were to fit the spectra predicted by the simulations either with no model for baryons, or with the proposed method. We show that neglecting baryonic effect leads to biases in dark energy parameters that are several times the statistical errors for a survey like the Dark Energy Survey. The proposed method to correct for ...
Impact of finite density on spectroscopic parameters of decuplet baryons
Azizi, K; Sundu, H
2016-01-01
The decuplet baryons, $\\Delta$, $\\Sigma^{*}$, $\\Xi^{*}$ and $\\Omega^{-}$, are studied in nuclear matter by using the in-medium QCD sum rules. By fixing the three momentum of the particles under consideration at the rest frame of the medium, the negative energy contributions are removed. It is obtained that the parameters of the $\\Delta$ baryon are more affected by the medium against the $\\Omega^{-}$ state, containing three strange quarks, whose mass and residue do not affected by the medium, considerably. We also find the vector and scalar self energies of these baryons in nuclear matter. By the recent progresses at $\\bar{P}$ANDA experiment at FAIR it may be possible to study the in-medium properties of such states even the multi-strange $\\Xi^{*}$ and $\\Omega^{-}$ systems in near future.
Baryon stopping and saturation physics at RHIC and LHC
Mehtar-Tani, Yacine
2009-01-01
We investigate baryon transport in relativistic heavy-ion collisions at energies reached at the CERN Super Proton Synchrotron, BNL Relativistic Heavy-Ion Collider (RHIC), and CERN LHC in the model of saturation. An analytical scaling law is derived within the color glass condensate framework based on small-coupling QCD. Transverse momentum spectra, net-baryon rapidity distributions and their energy, mass and centrality dependences are well described. In a comparison with RHIC data in Au + Au collisions at sqrt (s_NN) = 62.4 GeV and 200 GeV, the gradual approach to the gluon saturation regime is investigated, and limits for the saturation-scale exponent are determined. Predictions for net-baryon rapidity spectra and the mean rapidity loss in central Pb + Pb collisions at LHC energies of sqrt (s_NN) = 5.52 TeV are made.
Baryon electric dipole moments from strong CP violation
Guo, Feng-Kun; Meißner, Ulf-G.
2012-12-01
The electric dipole form factors and moments of the ground state baryons are calculated in chiral perturbation theory at next-to-leading order. We show that the baryon electric dipole form factors at this order depend only on two combinations of low-energy constants. We also derive various relations that are free of unknown low-energy constants. We use recent lattice QCD data to calculate all baryon EDMs. In particular, we find d n = -2 .9 ± 0 .9 and d p = 1 .1 ± 1 .1 in units of 10-16 e θ 0 cm. Finite volume corrections to the electric dipole moments are also worked out. We show that for a precision extraction from lattice QCD data, the next-to-leading order terms have to be accounted for.
Moduli induced cogenesis of baryon asymmetry and dark matter
Dhuria, Mansi; Sarkar, Utpal
2015-01-01
We study a cogenesis mechanism in which the observed baryon asymmetry of the universe and the dark matter abundance can be produced simultaneously at low reheating temperature without violating baryon number in the fundamental vertex. In particular, we consider a model which could be realized in the context of type IIB large volume string compactifications. The matter superfields in this model include additional pairs of color triplet and singlet superfields in addition to the Minimal Supersymmetric Standard Model (MSSM) superfields. Assuming that the mass of the additional singlet fermions is O(GeV) and color triplet fermions is O(TeV), we show that the modulus dominantly decays into the additional color triplet superfields. After soft supersymmetry (SUSY) breaking, the lightest eigenstate of scalar component of color triplet superfield further decays into fermionic component of singlet superfield and quarks without violating baryon number. Assuming R-parity conservation, it follows that the singlet superfie...
Studies in the production of baryons in 500 GeV/c {pi}{sup -} nucleon interactions
Energy Technology Data Exchange (ETDEWEB)
Solano, Javier [Escola Federal de Engenharia de Itajuba (ICI/EFEI), MG (Brazil). Inst. de Ciencias; Anjos, J.C. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Lab. de Cosmologia e Fisica Experimental de Altas Energias (LAFEX)
2000-07-01
Full text follows: Using data from Fermilab fixed-target experiment E791, we have measured particle-antiparticle production asymmetries for {lambda}, {xi}, and {omega}, and {lambda}{sub c} baryons in {pi}{sup -} -nucleon interactions at 500 GeV/c as functions of Feynman x (x{sub F} ) and transverse momentum squared ({pi}{sub T}{sup 2}). This asymmetry measurement are the first in both the positive and negative x{sub F} regions in a fixed target experiment. For {lambda}{sub c} we have measured as well the polarization in a multidimensional resonance analysis. (author)
The hidden charm pentaquarks are the hidden color-octet $uud$ baryons?
Takeuchi, Sachiko
2016-01-01
The $I(J^P)={1\\over 2}({1\\over 2}^-)$, ${1\\over 2}({3\\over 2}^-)$, and ${1\\over 2}({5\\over 2}^-)$ $uudc\\overline{c}$ pentaquarks are investigated by the quark cluster model. This model, which reproduces the mass spectra of the color-singlet $S$-wave $q^3$ baryons and $q\\overline{q}$ mesons, also enables us to evaluate the quark interaction in the color-octet $uud$ configurations. It is shown that the color-octet isospin-${1\\over 2}$ spin-${3\\over 2}$ $uud$ configuration gains attraction. The $uudc\\overline{c}$ states with this configuration cause structures around the $\\Sigma_c{}^{(*)}\\overline{D}{}^{(*)}$ thresholds: one bound state, two resonances, and one large cusp are found. We argue that the negative parity pentaquark found by the LHCb experiments may be given by these structures.
S=--1 Meson-Baryon Scattering in Coupled Channel Unitarized Chiral Perturbation Theory
García-Recio, C; Ruiz-Arriola, E; Vacas, M J V
2003-01-01
The $s-$wave meson-baryon scattering amplitude is analyzed for the strangeness $S=-1$ and isospin I=0 sector in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry. Four two-body channels have been considered: $\\bar K N$, $\\pi \\Sigma $, $\\eta \\Lambda $, $ K \\Xi$. The needed two particle irreducible matrix amplitude is taken from lowest order Chiral Perturbation Theory in a relativistic formalism. Off-shell behaviour is parameterized in terms of low energy constants, which outnumber those assumed in previous works and provide a better fit to the data. The position of the complex poles in the second Riemann sheet of the scattering amplitude determine masses and widths of the $\\Lambda (1405)$ and $\\Lambda(1670)$ resonances which compare well with accepted numbers.
S=-1 meson-baryon scattering in coupled-channel unitarized Chiral Perturbation Theory
Energy Technology Data Exchange (ETDEWEB)
Garcia-Recio, C.; Nieves, J.; Ruiz Arriola, E. [Departamento de Fisica Moderna, Universidad de Granada, E-18071, Granada (Spain); Vicente Vacas, M. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Ap. Correos 22085, E-46071, Valencia (Spain)
2003-11-01
The s-wave meson-baryon scattering amplitude is analyzed for the strangeness S=-1 and isospin I=0 sector in a Bethe-Salpeter coupled-channel formalism incorporating Chiral Symmetry. Four two-body channels have been considered: anti K N, {pi}{sigma}, {eta}{lambda}, K {xi}. The needed two-particle irreducible matrix amplitude is taken from lowest-order Chiral Perturbation Theory in a relativistic formalism. Off-shell behaviour is parameterized in terms of low-energy constants, which outnumber those assumed in previous works and provide a better fit to the data. The position of the complex poles in the second Riemann sheet of the scattering amplitude determines masses and widths of the {lambda}(1405) and {lambda}(1670) resonances which compare well with accepted numbers. (orig.)
Evidence for B Semileptonic Decays into the Lambda_c Charm Baryon
Energy Technology Data Exchange (ETDEWEB)
Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, Antimo; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, Bjarne; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Cahn, Robert N.; Jacobsen, R.G.; /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Banca di Roma /Frascati /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison
2008-11-05
We present the first evidence for B semileptonic decays into the charmed baryon {Lambda}{sub c}{sup +} based on 420 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We measure the relative branching fraction {Beta}({bar B} {yields} {Lambda}{sub c}{sup +} X{ell}{sup -}{bar {nu}}{sub {ell}})/{Beta}({bar B} {yields} {Lambda}{sub c}{sup +}/{bar {Lambda}}{sub c}{sup -}X) = (3.2 {+-} 0.9{sub stat.} {+-} 0.9{sub syst.})%. The significance of the signal including the systematic uncertainty is 4.9 standard deviations.
Faessler, A; Holstein, Barry R; Lyubovitskij, V E; Nicmorus, D; Pumsa-ard, K; Faessler, Amand; Gutsche, Thomas; Holstein, Barry R.; Lyubovitskij, Valery E.; Nicmorus, Diana; Pumsa-ard, Kem
2006-01-01
We calculate magnetic moments of light baryons and N -> Delta gamma transition characteristics using a manifestly Lorentz covariant chiral quark approach for the study of baryons as bound states of constituent quarks dressed by a cloud of pseudoscalar mesons.
Magnetic Moments of Baryons containing all heavy quarks in Quark-Diquark Model
Thakkar, Kaushal; Vinodkumar, P C
2016-01-01
The triply heavy flavour baryons are studied using the Quark-diquark description of the three-body system. The confinement potential for present study of triply heavy flavour baryons is assumed as coulomb plus power potential with power index $\
Energy Technology Data Exchange (ETDEWEB)
Wu Jiajun, E-mail: wujiajun@ihep.ac.cn [Institute of High Energy Physics, CAS, P.O. Box 918(4), Beijing 100049 (China); Zhao Lu [Institute of High Energy Physics, CAS, P.O. Box 918(4), Beijing 100049 (China); Zou, B.S. [Institute of High Energy Physics, CAS, P.O. Box 918(4), Beijing 100049 (China); Theoretical Physics Center for Science Facilities, CAS, Beijing 100049 (China)
2012-03-13
The meson-baryon coupled channel unitary approach with the local hidden gauge formalism is extended to the hidden beauty sector. A few narrow N{sup Low-Asterisk} and {Lambda}{sup Low-Asterisk} resonances around 11 GeV are predicted as dynamically generated states from the interactions of heavy beauty mesons and baryons. Production cross sections of these predicted resonances in pp and ep collisions are estimated as a guide for the possible experimental search at relevant facilities.
Study of Doubly Heavy Baryon Spectrum via QCD Sum Rules
Institute of Scientific and Technical Information of China (English)
TANG Liang; YUAN Xu-Hao; QIAO Cong-Feng; LI Xue-Qian
2012-01-01
In this work, we calculate the mass spectrum of doubly heavy baryons with the diquaxk model in terms of the QCD sum rules. The interpolating currents are composed of a heavy diquaxk field and a light quark field. Contributions of the operators up to dimension six are taken into account in the operator product expansion. Within a reasonable error tolerance, our numerical results axe compatible with other theoretical predictions. This indicates that the diquaxk picture reflects the reality and is applicable to the study of doubly heavy baryons.
Baryon inhomogeneities in a charged quark gluon plasma
Energy Technology Data Exchange (ETDEWEB)
Ray, Avijeet [Indian Institute of Technology Roorkee, Uttarakhand, 247667 (India); Sanyal, Soma, E-mail: sossp@uohyd.ernet.in [School of Physics, University of Hyderabad, Gachibowli, Hyderabad, 500046 (India)
2013-10-07
We study the generation of baryon inhomogeneities in regions of the quark gluon plasma which have a charge imbalance. We find that the overdensity in the baryon lumps for positively charged particles is different from the overdensity due to the negatively charged particles. Since quarks are charged particles, the probability of forming neutrons or protons in the lumps would thus be changed. The probability of forming hadrons having quarks of the same charges would be enhanced. This might have interesting consequences for the inhomogeneous nucleosynthesis calculations.
Transition magnetic moments between negative parity heavy baryons
Aliev, T M; Savci, M
2015-01-01
The transition magnetic moments between negative parity, spin-1/2 heavy baryons are studied in framework of the light cone QCD sum rules. By constructing the sum rules for different Lorentz structures, the unwanted contributions coming from negative (positive) to positive (negative) parity transitions are removed. It is found that the magnetic moments between neutral negative parity heavy $\\Xi_Q^{\\prime 0}$ and $\\Xi_Q^0$ baryons are very small. Magnetic moments of the $\\Sigma_Q \\to \\Lambda_Q$ and $ \\Xi_Q^{\\prime \\pm} \\to \\Xi_Q^\\pm$ transitions are quite large and can be measured in further experiments.
Baryon Wave Functions in Covariant Relativistic Quark Models
Dillig, M
2002-01-01
We derive covariant baryon wave functions for arbitrary Lorentz boosts. Modeling baryons as quark-diquark systems, we reduce their manifestly covariant Bethe-Salpeter equation to a covariant 3-dimensional form by projecting on the relative quark-diquark energy. Guided by a phenomenological multigluon exchange representation of a covariant confining kernel, we derive for practical applications explicit solutions for harmonic confinement and for the MIT Bag Model. We briefly comment on the interplay of boosts and center-of-mass corrections in relativistic quark models.
Baryon Asymmetry, Neutrino Mixing and Supersymmetric SO(10) Unification
Plümacher, Michael
1998-01-01
The baryon asymmetry of the universe can be explained by the out-of-equilibrium decays of heavy right-handed neutrinos. We analyse this mechanism in the framework of a supersymmetric extension of the Standard Model and show that lepton number violating scatterings are indispensable for baryogenesis, even though they may wash-out a generated asymmetry. By assuming a similar pattern of mixings and masses for neutrinos and up-type quarks, as suggested by SO(10) unification, we can generate the observed baryon asymmetry without any fine tuning, if (B-L) is broken at the unification scale preferred by the MSW solution to the solar neutrino deficit.
On Exotic Systems of Baryons in Chiral Soliton Models
Kopeliovich, Vladimir
2016-01-01
The role of zero mode quantum corrections to the energy of baryonic systems with exotic quantum numbers (strangeness) is discussed. A simple expression for the contribution depending on strange inertia is obtained in the $SU(3)-$collective coordinate quantization approach, and it is shown that this correction stabilizes the systems the stronger the greater their baryon number is. Furthemore, systems are considered which could be interpreted in the quark model language as containing additional $q\\bar q-$pairs. It is argued that a strange skyrmion crystal should have additional binding in comparison with the $SU(2)-$quantized neutron crystal.
Baryon symmetric big-bang cosmology. [matter-antimatter symmetry
Stecker, F. W.
1978-01-01
The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.
Diquark correlations in baryons on the lattice with overlap quarks
Energy Technology Data Exchange (ETDEWEB)
Babich, R.; Howard, J.; Rebbi, C. [Boston Univ., MA (United States). Dept. of Physics; Garron, N. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hoelbling, C. [Wuppertal Univ. (Gesamthochschule) (Germany). Fachbereich Physik; Lellouch, L. [CNRS Luminy, Marseille (France). Centre de Physique Theorique]|[Wuppertal Univ. (Gesamthochschule) (Germany). Fachbereich Physik
2007-01-15
We evaluate baryon wave functions in both the Coulomb and Landau gauge in lattice QCD. These are constructed from quark propagators calculated with the overlap Dirac operator on quenched gauge configurations at {beta}=6. By comparing baryon states that differ in their diquark content, we find evidence for enhanced correlation in the scalar diquark channel, as favored by quark models. We also summarize earlier results for diquark masses in the Landau gauge, casting them in a form more easily compared with subsequent studies. (orig.)
Effect of higher orbital angular momenta in the baryon spectrum
Garcilazo, H; Fernández, F
2001-01-01
We have performed a Faddeev calculation of the baryon spectrum for the chiral constituent quark model including higher orbital angular momentum states. We have found that the effect of these states is important, although a description of the baryon spectrum of the same quality as the one given by including only the lowest-order configurations can be obtained. We have studied the effect of the pseudoscalar quark-quark interaction on the relative position of the positive- and negative-parity excitations of the nucleon as well as the effect of varying the strength of the color-magnetic interaction.
Magnetic moments of heavy baryons in the relativistic three-quark model
Faessler, A; Ivanov, M A; Körner, J G; Lyubovitskij, V E; Nicmorus, D; Pumsa-ard, K; Faessler, Amand; Gutsche, Th.
2006-01-01
The magnetic moments of ground state single, double and triple heavy baryons containing charm or bottom quarks are calculated in a relativistic three-quark model, which, in the heavy quark limit, is consistent with Heavy Quark Effective Theory and Heavy Hadron Chiral Perturbation Theory. The internal quark structure of baryons is modeled by baryonic three-quark currents with a spin-flavor structure patterned according to standard covariant baryonic wave functions and currents used in QCD sum rule calculations.
Li, Hao-Song; Chen, Xiao-Lin; Deng, Wei-Zhen; Zhu, Shi-Lin
2016-01-01
We have systematically investigated the magnetic moments and magnetic form factors of the decuplet baryons to the next-to-next-leading order in the framework of the heavy baryon chiral perturbation theory. Our calculation includes the contributions from both the intermediate decuplet and octet baryon states in the loops. We also calculate the charge and magnetic dipole form factors of the decuplet baryons. Our results may be useful to the chiral extrapolation of the lattice simulations of the decuplet electromagnetic properties.
On the quark-mass dependence of baryon ground-state masses
Energy Technology Data Exchange (ETDEWEB)
Semke, Alexander
2010-02-17
Baryon masses of the flavour SU(3) octet and decuplet baryons are calculated in the framework of the Chiral Perturbations Theory - the effective field theory of the strong interaction. The chiral extrapolation to the higher meson (quark) masses is carried out. The comparison with the recent results on the baryon masses from lattice calculations are presented. (orig.)
Baryon spectroscopy with polarization observables from CLAS
Energy Technology Data Exchange (ETDEWEB)
Strauch, Steffen [Univ. of South Carolina, Columbia, SC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2016-11-01
The spectrum of nucleon excitations is dominated by broad and overlapping resonances. Polarization observables in photoproduction reactions are key in the study of these excitations. They give indispensable constraints to partial-wave analyses and help clarify the spectrum. A series of polarized photoproduction experiments have been performed at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer (CLAS). These measurements include data with linearly and circularly polarized tagged-photon beams, longitudinally and transversely polarized proton and deuterium targets, and recoil polarizations through the observation of the weak decay of hyperons. An overview of these studies and recent results will be given.
Three Baryon Interaction Generated by Determinant Interaction of Quarks
Ohnishi, Akira; Morita, Kenji
2016-01-01
We discuss the three-baryon interaction generated by the determinant interaction of quarks, known as the Kobayashi-Maskawa-'t Hooft (KMT) interaction. The expectation value of the KMT interaction operator is calculated in fully-antisymmetrized quark-cluster model wave functions for one-, two- and three-octet baryon states. The three-baryon potential from the KMT interaction is found to be repulsive for $NN\\Lambda$ and $N\\Lambda\\Lambda$ systems, while it is zero for the $NNN$ system. The strength and range of the three-baryon potential are found to be comparable to those for the $NNN$ three-body potential obtained in lattice QCD simulations. The contribution to the $\\Lambda$ single particle potential in nuclear matter is found to be 0.28 MeV and 0.73 MeV in neutron matter and symmetric nuclear matter at normal nuclear density, respectively. These repulsive forces are not enough to solve the hyperon puzzle, but may be measured in high-precision hyperisotope experiments.
The baryon fraction in hydrodynamical simulations of galaxy clusters
Ettori, S; Borgani, S; Murante, G
2006-01-01
We study the baryon mass fraction in a set of hydrodynamical simulations of galaxy clusters performed using the Tree+SPH code GADGET-2. We investigate the dependence of the baryon fraction upon the radiative cooling, star formation, feedback through galactic winds, conduction and redshift. Both the cold stellar component and the hot X-ray emitting gas have narrow distributions that, at large cluster-centric distances r>R500, are nearly independent of the physics included in the simulations. Only the non-radiative runs reproduce the gas fraction inferred from observations of the inner regions (r ~ R2500) of massive clusters. When cooling is turned on, the excess star formation is mitigated by the action of galactic winds, but yet not by the amount required by observational data. The baryon fraction within a fixed overdensity increases slightly with redshift, independent of the physical processes involved in the accumulation of baryons in the cluster potential well. In runs with cooling and feedback, the increa...
Baryomorphosis: Relating the Baryon Asymmetry to the "WIMP Miracle"
McDonald, John
2010-01-01
We present a generic framework, "baryomorphosis", which modifies the baryon asymmetry to be naturally of the order of a typical thermal relic WIMP density. We consider a simple scalar-based model to show how this is possible. This model introduces a sector in which a large initial baryon asymmetry is injected into particles ("annihilons"), phi_{B}, phi_{B, hat}, of mass ~ 100 GeV - 1 TeV. phi_{B}-phi_{B, hat} annihilations convert the initial phi_{B}, phi_{B, hat} asymmetry to a final asymmetry with a thermal relic WIMP-like density. This subsequently decays to a conventional baryon asymmetry whose magnitude is naturally related to the density of thermal relic WIMP dark matter. In this way the two coincidences of baryons and dark matter i.e. why their densities are similar to each other and why they are both similar to a WIMP thermal relic density (the "WIMP miracle"), may be understood. The model can be tested by the production of annihilons at colliders.
First Observation of a Baryonic B-c(+) Decay
Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Brown, H.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Perez, D. Campora; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Akiba, K. Carvalho; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cojocariu, L.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. -M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R. F.; Ferguson, D.; Fernandez Albor, V.; Rodrigues, F. Ferreira; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gavrilov, G.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Graciani Diaz, R.; Cardoso, L. A. Granado; Grauges, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kaballo, M.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez-March, N.; Lowdon, P.; Lu, H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martens, A.; Sanchez, A. Martin; Martinelli, M.; Santos, D. Martinez; Martinez Vidal, F.; Tostes, D. Martins; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; Mcnab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. -N.; Moggi, N.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. -B.; Mountain, R.; Muheim, F.; Mueller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, G.; Orlandea, M.; Goicochea, J. M. Otalora; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pazos Alvarez, A.; Pearce, A.; Pellegrino, A.; Altarelli, M. Pepe; Perazzini, S.; Perez Trigo, E.; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Romero, D. A. Roa; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Silva, J. J. Saborido; Sagidova, N.; Sail, P.; Saitta, B.; Guimaraes, V. Salustino; Mayordomo, C. Sanchez; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrie, M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. -H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Seco, M.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; De Paula, B. Souza; Spaan, B.; Sparkes, A.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V. K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szilard, D.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Sierra, C. Vzquez; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; Voss, H.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wu, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A.
2014-01-01
A baryonic decay of the B-c(+) meson, B-c(+) -> J/psi p (p) over bar pi(+) is observed for the first time, with a significance of 7.3 standard deviations, in pp collision data collected with the LHCb detector and corresponding to an integrated luminosity of 3.0 fb(-1) taken at center-of-mass energie
The inner regions of disk galaxies: a constant baryonic fraction?
Lelli, Federico
2014-01-01
For disk galaxies (spirals and irregulars), the inner circular-velocity gradient (inner steepness of the rotation curve) correlates with the central surface brightness with a slope of ~0.5. This implies that the central dynamical mass density scales almost linearly with the central baryonic density. Here I show that this empirical relation is consistent with a simple model where the central baryonic fraction f_bar(0) is fixed to 1 (no dark matter) and the observed scatter is due to differences in the baryonic mass-to-light ratio M_bar/L (ranging from 1 to 3 in the R-band) and in the characteristic thickness of the central stellar component dz (ranging from 100 to 500 pc). Models with lower baryonic fractions are possible, although they require some fine-tuning in the values of M_bar/L and dz. Regardless of the actual value of f_bar(0), the fact that different types of galaxies do not show strong variations in f_bar(0) is surprising, and may represent a challenge for models of galaxy formation in a LCDM cosmol...
Pion photo- and electroproduction in relativistic baryon ChPT
Directory of Open Access Journals (Sweden)
Tiator Lothar
2014-06-01
Full Text Available We present a calculation of pion photo- and electroproduction in manifestly Lorentz-invariant baryon chiral perturbation theory up to and including order q4. We fix the low-energy constants by fitting experimental data in all available reaction channels. Our results can be accessed via a web interface, the so-called chiral MAID.
Radiative decays of negative parity heavy baryons in QCD
Agamaliev, A K; Savcı, M
2016-01-01
The transition form factors responsible for the radiative $\\Sigma_Q \\to \\Lambda_Q \\gamma$ and $\\Xi_Q^\\prime \\to \\Xi \\gamma$ decays of the negative parity baryons are examined within light cone QCD sum rules. The decay widths of the radiative transitions are calculated using the obtained results of the form factors.
Algebraic models of hadron structure I. Nonstrange baryons
Bijker, R; Leviatan, A
1994-01-01
We introduce an algebraic framework for the description of baryons. Within this framework we study a collective string-like model and show that this model gives a good overall description of the presently available data. We discuss in particular masses and electromagnetic couplings, including the transition form factors that can be measured at new electron facilities.
Algebraic models of hadron structure. I. Nonstrange baryons
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Univ. of Utrecht (Netherlands); Iachello, F. [Yale Univ., New Haven, CT (United States); Leviatan, A. [Hebrew Univ., Jerusalem (Israel)
1994-11-15
The authors introduce an algebraic framework for the description of baryons. Within this framework they study a collective string-like model and show that this model gives a good overall description of the presently available data. They discuss in particular masses and electromagnetic couplings, including the transition form factors that can be measured at new electron facilities. 44 refs., 15 figs., 11 tabs.
Dense baryonic matter in strong coupling lattice gauge theory
Bringoltz, B
2004-01-01
We investigate the strong coupling limit of lattice QCD in the Hamiltonian formulation for systems with non-zero baryon density. In leading order the Hamiltonian looks like an antiferromagnet that is invariant under global U(N_f)xU(N_f) and local SU(N_c). Physically it describes meson dynamics with a fixed background of baryon density. We study this Hamiltonian with several baryon number distributions, and concentrate on the global symmetries of the ground state and on the properties of low lying excitations. In particular, for uniform non-zero baryon density we write the partition function as a path integral that is tractable in the limit of large N_c. We find that the ground state spontaneously breaks chiral symmetry as well as discrete lattice rotations in a way that depends on N_f and the density. The low energy excitations include type I and type II Goldstone bosons. The energies of the latter are of order 1/N_c, and are quadratic in momentum. Bosons of either type can develop anisotropic dispersion rela...
Constraining Dark Matter-Baryon Scattering with Linear Cosmology
Dvorkin, Cora; Kamionkowski, Marc
2013-01-01
We derive constraints on elastic scattering between baryons and dark matter using the cosmic microwave background (CMB) data from the Planck satellite and the Lyman-alpha forest data from the Sloan Digital Sky Survey. Elastic scattering allows baryons and dark matter to exchange momentum, affecting the dynamics of linear density perturbations in the early Universe. We derive constraints to scattering cross sections of the form sigma \\propto v^n, allowing for a wide range of velocity dependencies with n between -4 and 2. We improve and correct previous estimates where they exist, including velocity-independent cross section as well as dark matter millicharge and electromagnetic dipole moments. Lyman-alpha forest data dominates the constraints for n>-3, where the improvement over CMB data alone can be several orders of magnitude. Dark matter-baryon scattering cannot affect the halo mass function on mass scales M>10^{12} M_{solar}. Our results imply, model-independently, that a baryon in the halo of a galaxy lik...
New Observations of beauty baryon decays at LHCb
Vitaly, Andreev
2014-01-01
This report describes the work I have done during my summer student association with the LHCb (Large Hadron Collider Beauty Experiment) collaboration at CERN from 30.06 till 26.09.2014. The project was performed in a team with two other summer students. In this report I concentrate on my contribution to the team work. In addition, one section is dedicated to the management framework called “scrum” which we used to collaborate as a team. The goal of my task was to analyze yet unobserved decays of the beauty Lambda-b-0 baryon. This is interesting since the CP violation still remains unobserved in baryons and beauty baryons are generally not well-known yet. LHCb is the first detector where these heavy baryons can be analyzed in detail. In addition these decays may play an important role in other processes and one can gain new insights into the strong interaction. The analysis presented here was performed on the full 2011-2012 LHC run data and includes several decays which are observed for the first time.
Factorization of heavy-to-light baryonic transitions in SCET
Energy Technology Data Exchange (ETDEWEB)
Wang, Wei
2011-12-15
In the framework of the soft-collinear effective theory, we demonstrate that the leading-power heavy-to-light baryonic form factors at large recoil obey the heavy quark and large energy symmetries. Symmetry breaking effects have several origins but all of them are suppressed by {lambda}/m{sub b} or {lambda}/E, where {lambda} is the hadronic scale, m{sub b} is the b quark mass and E{proportional_to}m{sub b} is the energy of light baryon in the final state. Including the energy release dependence, we derive the scaling law for form factors {xi}{sub {lambda}}{sub ,p}{proportional_to}{lambda}{sup 2} /E{sup 2}, which is in accordance with the implication from the experimental measurement on the branching ratio of {lambda}{sub b} {yields} p{pi}{sup -}. At leading order in {alpha}{sub s}, the leading-power baryonic form factors can factorize into the soft and collinear matrix elements without encountering any divergence. A leading-power factorization formula for nonleptonic b-baryon decays is also established. (orig.)
The Inner Regions of Disk Galaxies: A Constant Baryonic Fraction?
Directory of Open Access Journals (Sweden)
Federico Lelli
2014-07-01
Full Text Available For disk galaxies (spirals and irregulars, the inner circular-velocity gradient dRV0 (inner steepness of the rotation curve correlates with the central surface brightness ∑*,0 with a slope of ~0.5. This implies that the central dynamical mass density scales almost linearly with the central baryonic density. Here I show that this empirical relation is consistent with a simple model where the central baryonic fraction ƒbar,0 is fixed to 1 (no dark matter and the observed scatter is due to differences in the baryonic mass-to-light ratio Mbar / LR (ranging from 1 to 3 in the R-band and in the characteristic thickness of the central stellar component Δz (ranging from 100 to 500 pc. Models with lower baryonic fractions are possible, although they require some fine-tuning in the values of Mbar/LR and Δz. Regardless of the actual value of ƒbar,0, the fact that different types of galaxies do not show strong variations in ƒbar,0 is surprising, and may represent a challenge for models of galaxy formation in a Λ Cold Dark Matter (ΛCDM cosmology.
Chekanov, S.; Derrick, M.; Loizides, J.H.; Magill, S.; Miglioranzi, S.; Musgrave, B; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Pavel, N.; Antonioli, P.; Bari, G.(INFN Bologna, Bologna, Italy); Basile, M.; Bellagamba, L.; Boscherini, D.
2004-01-01
A resonance search has been made in the K(S)(0)p and K-S(0)(p) over bar invariant-mass spectrum measured with the ZEUS detector at HERA using an integrated luminosity of 121 pb(-1). The search was performed in the central rapidity region of inclusive deep inelastic scattering at an ep centre-of-mass energy of 300-318 GeV for exchanged photon virtuality, Q(2), above 1 GeV2. Recent results from fixed-target experiments give evidence for a narrow baryon resonance decaying to K(+)n and K(S)(0)p, ...
Thermodynamics of Hot Hadronic Gases at Finite Baryon Densities
Albright, Michael Glenn
In this thesis we investigate equilibrium and nonequilibrium thermodynamic properties of Quantum Chromodynamics (QCD) matter at finite baryon densities. We begin by constructing crossover models for the thermodynamic equation of state. These use switching functions to smoothly interpolate between a hadronic gas model at low energy densities to a perturbative QCD equation of state at high energy densities. We carefully design the switching function to avoid introducing first-, second-, or higher-order phase transitions which lattice QCD indicates are not present at small baryon chemical potentials. We employ three kinds of hadronic models in the crossover constructions, two of which include repulsive interactions via an excluded volume approximation while one model does not. We find that the three crossover models are in excellent agreement with accurate lattice QCD calculations of the equation of state over a wide range of temperatures and baryon chemical potentials. Hence, the crossover models should be very useful for parameterizing the equation of state at finite baryon densities, which is needed to build next-generation hydrodynamic simulations of heavy-ion collisions. We next calculate the speed of sound and baryon number fluctuations predicted by the crossover models. We find that crossover models with hadronic repulsion are most successful at reproducing the lattice results, while the model without repulsion is less successful, and hadron (only) models show poor agreement. We then compare the crossover models to net-proton fluctuation measurements from the STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC). The comparisons suggest baryon number fluctuations freeze-out well below the chemical freeze-out temperature. We also search for signs of critical fluctuations in the STAR data, but we find no evidence for them at this time. Finally, we derive kinetic theory formulas for the shear and bulk viscosity and thermal conductivity of hot hadronic
Simultaneous Generation of WIMP Miracle-like Densities of Baryons and Dark Matter
McDonald, John
2012-09-01
The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Production of unstable scalars carrying baryon number at the LHC would be a clear signature of the model.
Generation of WIMP Miracle-like Densities of Baryons and Dark Matter
McDonald, John
2012-01-01
The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Production of unstable scalars carrying baryon number at the LHC would be a clear signature of the model.
Magnetic Moments of Octet Baryons in Hot and Dense Nuclear Matter
Singh, Harpreet; Dahiya, Harleen
2016-01-01
We have calculated the in-medium magnetic moments of octet baryons in the presence of hot and dense symmetric nuclear matter. Effective magnetic moments of baryons have been derived from medium modified quark masses within chiral SU(3) quark mean field model.Further, for better insight of medium modification of baryonic magnetic moments, we have considered the explicit contributions from the valence as well as sea quark effects. These effects have been successful in giving the description of baryonic magnetic moments in vacuum. The magnetic moments of baryons are found to vary significantly as a function of density of nuclear medium.
Intriguing aspects in baryon production at relativistic heavy-ion collider
Indian Academy of Sciences (India)
Huan Zhong Huang
2003-05-01
We review experimental results on baryon production at mid-rapidity in nucleus–nucleus collisions at RHIC. Outstanding physics issues include the mechanism for baryon–anti-baryon production from thermally equilibrated partons, the dynamics of baryon number transport and the evolution dynamics of baryons during hadronic expansion before the ﬁnal freeze-out. We highlight recent measurements on the production of protons, lambdas and their anti-particles in terms of these physics issues. We propose a physical mechanism of topological baryon formation through gluon junction hadronization and future measurements, which can test this hypothesis experimentally.
Fujiwara, Y; Suzuki, Y
2006-01-01
We calculate Lambda alpha, Sigma alpha and Xi alpha potentials from the nuclear-matter G-matrices of the SU6 quark-model baryon-baryon interaction. The alpha-cluster wave function is assumed to be a simple harmonic-oscillator shell-model wave function. A new method is proposed to derive the direct and knock-on terms of the interaction Born kernel from the hyperon-nucleon G-matrices, with explicit treatments of the nonlocality and the center-of-mass motion between the hyperon and alpha. We find that the SU6 quark-model baryon-baryon interactions, FSS and fss2, yield a reasonable bound-state energy for 5 He Lambda, -3.18 -- -3.62 MeV, in spite of the fact that they give relatively large depths for the Lambda single-particle potentials, 46 -- 48 MeV, in symmetric nuclear matter. An equivalent local potential derived from the Wigner transform of the nonlocal Lambda alpha kernel shows a strong energy dependence for the incident Lambda-particle, indicating the importance of the strangeness-exchange process in the o...
Haidenbauer, J.; Meißner, Ulf-G.; Petschauer, S.
2016-10-01
The strangeness S = - 2 baryon-baryon interaction is studied in chiral effective field theory up to next-to-leading order. The potential at this order consists of contributions from one- and two-pseudoscalar-meson exchange diagrams and from four-baryon contact terms without and with two derivatives. SU(3) flavor symmetry is imposed for constructing the interaction in the S = - 2 sector. Specifically, the couplings of the pseudoscalar mesons to the baryons are fixed by SU(3) symmetry and, in general, also the contact terms are related via SU(3) symmetry to those determined in a previous study of the S = - 1 hyperon-nucleon interaction. The explicit SU(3) symmetry breaking due to the physical masses of the pseudoscalar mesons (π, K, η) is taken into account. It is argued that the ΞN interaction has to be relatively weak to be in accordance with available experimental constraints. In particular, the published values and upper bounds for the Ξ- p elastic and inelastic cross sections apparently rule out a somewhat stronger attractive ΞN force and, specifically, disfavor any near-threshold deuteron-like bound states in that system.
Appelquist, Thomas; Brower, Richard C; Buchoff, Michael I; Fleming, George T; Kiskis, Joe; Kribs, Graham D; Lin, Meifeng; Neil, Ethan T; Osborn, James C; Rebbi, Claudio; Rinaldi, Enrico; Schaich, David; Schroeder, Chris; Syritsyn, Sergey; Voronov, Gennady; Vranas, Pavlos; Weinberg, Evan; Witzel, Oliver
2014-01-01
We present the spectrum of baryons in a new SU(4) gauge theory with fundamental fermion constituents. The spectrum of these bosonic baryons is of significant interest for composite dark matter theories. Here, we compare the spectrum and properties of SU(3) and SU(4) baryons, and then compute the dark-matter direct detection cross section via Higgs boson exchange for TeV-scale composite dark matter arising from a confining SU(4) gauge sector. Comparison with the latest LUX results leads to tight bounds on the fraction of the constituent-fermion mass that may arise from electroweak symmetry breaking. Lattice calculations of the dark matter mass spectrum and the Higgs-dark matter coupling are performed on quenched $16^{3} \\times 32$, $32^{3} \\times 64$, $48^{3} \\times 96$, and $64^{3} \\times128$ lattices with three different lattice spacings, using Wilson fermions with moderate to heavy pseudoscalar meson masses. Our results lay a foundation for future analytic and numerical study of composite baryonic dark matt...
Dynamical Fluctuations in Baryon--Meson Ratios
Tawfik, A
2010-01-01
The event-by-event dynamical fluctuations in kaon-to-proton and proton-to-pion ratios have been studied in dependence on center--of--mass energies of nucleon--nucleon collisions $\\sqrt{s}$. Based on changing phase space volume which apparently is the consequence of phase transition from hadrons to quark--gluon plasma at large $\\sqrt{s}$, the single--particle distribution function $f$ is assumed to be rather modified. Varying $f$ and phase space volume are implemented in the grand--canonical partition function, especially at $\\sqrt{s}>17$ GeV, so that hadron resonance gas model, when taking into account the experimental acceptance ${\\cal A}$ and quark phase space occupation factor $\\gamma$, turns to be able to reproduce the dynamical fluctuations in $(K^++K^-)/(p+\\overline{p})$ and $(p+\\overline{p})/(\\pi^++\\pi^-)$ ratios over the entire range of $\\sqrt{s}$.
Multiplicity fluctuation and correlation of identified baryons in quark combination model
Song, Jun; Wang, Rui-qin; Shao, Feng-lan
2016-01-01
The dynamical fluctuation and correlation of multiplicity distributions of identified baryons and antibaryons produced by the hadronization of the bulk quark system are systematically studied in quark combination model. Starting from the most basic dynamics of quark combination which are necessary for multiplicity study, we analyze moments (variance, skewness and kurtosis) of inclusive multiplicity distribution of identified baryons, two-baryon multiplicity correlations, and baryon-antibaryon multiplicity correlations after the hadronization of quark system with given quark number and antiquark number. We obtain a series of interesting findings, e.g., binomial behavior of multiplicity moments, coincide flavor dependent two-baryon correlation and universal baryon-antibaryon correlation, which can be regarded as general features of quark combination. We further take into account correlations and fluctuations of quark numbers before hadronization to study their influence on multiple production of baryons and ant...
Chiral analysis of baryon form factors
Energy Technology Data Exchange (ETDEWEB)
Gail, T.A.
2007-11-08
This work presents an extensive theoretical investigation of the structure of the nucleon within the standard model of elementary particle physics. In particular, the long range contributions to a number of various form factors parametrizing the interactions of the nucleon with an electromagnetic probe are calculated. The theoretical framework for those calculations is chiral perturbation theory, the exact low energy limit of Quantum Chromo Dynamics, which describes such long range contributions in terms of a pion-cloud. In this theory, a nonrelativistic leading one loop order calculation of the form factors parametrizing the vector transition of a nucleon to its lowest lying resonance, the {delta}, a covariant calculation of the isovector and isoscalar vector form factors of the nucleon at next to leading one loop order and a covariant calculation of the isoscalar and isovector generalized vector form factors of the nucleon at leading one loop order are performed. In order to perform consistent loop calculations in the covariant formulation of chiral perturbation theory an appropriate renormalization scheme is defined in this work. All theoretical predictions are compared to phenomenology and results from lattice QCD simulations. These comparisons allow for a determination of the low energy constants of the theory. Furthermore, the possibility of chiral extrapolation, i.e. the extrapolation of lattice data from simulations at large pion masses down to the small physical pion mass is studied in detail. Statistical as well as systematic uncertainties are estimated for all results throughout this work. (orig.)
a Study of the Decay Properties of the Charmed Baryon Charmed Positive Lambda Baryon
Charlesworth, Catriona Elizabeth Kaye
The charmed baryon Lambda_sp {c}{+} has been observed using the ARGUS detector in the DORIS II e^{+ }e^- storage ring at DESY. The ARGUS experiment is a 4pi magnetic solenoidal detector used to observe e^{+}e ^- annihilations at center-of-mass energies around 10.4 GeV. We have studied 5 decays modes of the Lambda_sp{c}{+}. The decay mode Lambda_sp{c} {+}to pK^-pi^+ was used to measure the Lambda_sp {c}{+} fragmentation properties. A value of 0.24 +/- 0.04 was found for the Peterson et al. parameter epsilon, and the sigma(Lambda_sp{c }{+}) cdot BR( Lambda_sp{c}{+}to pK^-pi^+) was measured to be 12.0 +/- 1.1 +/- 1.3) pb. The decay modes Lambda_sp {c}{+}toLambdapi^+ and Lambda_sp{c} {+}toSigma^0pi^+ were also studied. In the former the asymmetry parameter alpha_{Lambda _{c}} was measured to be -1.0 +/- 0.5, indicating that parity is maximally violated in this decay. The two production cross section times branching ratios were measured to be (2.2 +/- 0.3 +/- 0.3) pb and (2.0 +/- 0.7 +/- 0.3) pb respectively. Finally, a search was made for evidence of W-exchange in the decay Lambda_sp{c}{+} toXi^-K^+pi^+. This final state can arise through a simple spectator decay or via the more exotic W-exchange decay into Xi ^{*0}K^+, where the Xi^{*0} subsequently decays into Xi^-pi^+. The two body rate was measured to be (35 +/- 17)% of the three body rate, indicating that a significant portion of the Xi^-K^+pi ^+ final state may occur via W-exchange.
Resonance decay effect on conserved number fluctuations in a hadron resonance gas model
Mishra, D K; Netrakanti, P K; Mohanty, A K
2016-01-01
We study the effect of charged secondaries coming from resonance decay on the net-baryon, net-charge and net-strangeness fluctuations in high energy heavy-ion collisions within the hadron resonance gas (HRG) model. We emphasize the importance of including weak decays along with other resonance decays in the HRG, while comparing with the experimental observables. The effect of kinematic cuts on resonances and primordial particles on the conserved number fluctuations are also studied. The HRG model calculations with the inclusion of resonance decays and kinematical cuts are compared with the recent experimental data from STAR and PHENIX experiments. We find a good agreement between our model calculations and the experimental measurements for both net-proton and net-charge distributions.
Effect of resonance decay on conserved number fluctuations in a hadron resonance gas model
Mishra, D. K.; Garg, P.; Netrakanti, P. K.; Mohanty, A. K.
2016-07-01
We study the effect of charged secondaries coming from resonance decay on the net-baryon, net-charge, and net-strangeness fluctuations in high-energy heavy-ion collisions within the hadron resonance gas (HRG) model. We emphasize the importance of including weak decays along with other resonance decays in the HRG, while comparing with the experimental observables. The effect of kinematic cuts on resonances and primordial particles on the conserved number fluctuations are also studied. The HRG model calculations with the inclusion of resonance decays and kinematical cuts are compared with the recent experimental data from STAR and PHENIX experiments. We find good agreement between our model calculations and the experimental measurements for both net-proton and net-charge distributions.
Recent hadronic resonance measurements at ALICE
Knospe, A.G.
2016-01-01
In heavy-ion physics, measurements of short-lived hadronic resonances allow the properties of the hadronic phase of the collision to be studied. In addition, resonances can be used along with stable hadrons to study parton energy loss in the quark-gluon plasma and the mechanisms that shape hadron pT spectra at intermediate transverse momenta. Resonance measurements in small systems serve as a reference for heavy-ion collisions and contribute to searches for collective effects. An overview of recent results on hadronic resonance production measured in ALICE is presented. These results include the pT spectra and yields of the rho(770)0, K*(892)0, and phi(1020) mesons in pp, p-Pb, and Pb-Pb collisions at different energies as well as the Sigma(1385)+/- and Xi(1530)0 baryons in pp and p-Pb collisions.
Locating the "missing" baryons with extragalactic dispersion measure estimates
McQuinn, Matthew
2013-01-01
Recently, Thornton and coworkers (2013) confirmed a class of millisecond radio bursts likely of extragalactic origin that is well-suited for estimating dispersion measures (DMs). In addition, Lovelace and Richards (2013) showed that DM could be measured even towards non-variable extragalactic synchrotron sources. Motivated by these exciting results, we calculate the probability distribution of DM(z) in different models for how the cosmic baryons are distributed (both analytically and with cosmological simulations). We show that the distribution of DM is quite sensitive to whether the "missing" baryons lie around the virial radius of 10^11-10^13 Msun halos or further out, which is not easily constrained with other observational techniques. The intrinsic contribution to DM from each source could complicate studies of the extragalactic contribution. This difficulty is avoided by stacking based on the impact parameter to foreground galaxies. We show that a stacking analysis using a sample of ~100 DM measurements ...
Exodus: Hidden origin of dark matter and baryons
Unwin, James
2012-01-01
We propose a new framework for explaining the proximity of the baryon and dark matter relic densities \\Omega_{DM} \\approx 5\\Omega_B. The scenario assumes that the number density of the observed dark matter states is generated due to decays from a second hidden sector which simultaneously generates the baryon asymmetry. In contrast to asymmetric dark matter models, the dark matter can be a real scalar or Majorana fermion and thus presents distinct phenomenology. We discuss aspects of model building and general constraints in this framework. We present a simple supersymmetric implementation of this mechanism and show that it can be used to obtain the correct dark matter relic density for a bino LSP.
Exodus: Hidden origin of dark matter and baryons
Unwin, James
2013-06-01
We propose a new framework for explaining the proximity of the baryon and dark matter relic densities ΩDM ≈ 5Ω B . The scenario assumes that the number density of the observed dark matter states is generated due to decays from a second hidden sector which simultaneously generates the baryon asymmetry. In contrast to asymmetric dark matter models, the dark matter can be a real scalar or Majorana fermion and thus presents distinct phenomenology. We discuss aspects of model building and general constraints in this framework. Moreover, we argue that this scenario circumvents several of the experimental bounds which significantly constrain typical models of asymmetric dark matter. We present a simple supersymmetric implementation of this mechanism and show that it can be used to obtain the correct dark matter relic density for a bino LSP.
Quantifying the effect of baryon physics on weak lensing tomography
Semboloni, Elisabetta; Schaye, Joop; van Daalen, Marcel P; McCarthy, Ian J
2011-01-01
We use matter power spectra from cosmological hydrodynamic simulations to quantify the effect of baryon physics on the weak gravitational lensing shear signal. The simulations consider a number of processes, such as radiative cooling, star formation, supernovae and feedback from active galactic nuclei (AGN). Van Daalen et al. (2011) used the same simulations to show that baryon physics, in particular the strong feedback that is required to solve the overcooling problem, modifies the matter power spectrum on scales relevant for cosmological weak lensing studies. As a result, the use of power spectra from dark matter simulations can lead to significant biases in the inferred cosmological parameters. We show that the typical biases are much larger than the precision with which future missions aim to constrain the dark energy equation of state, w_0. For instance, the simulation with AGN feedback, which reproduces X-ray and optical properties of groups of galaxies, gives rise to a ~40% bias in w_0. We demonstrate ...
Supersonic Relative Velocity Effect on the Baryonic Acoustic Oscillation Measurements
Yoo, Jaiyul; Seljak, Uros
2011-01-01
We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum a...
Predictions for masses of Xi_b baryons
Karliner, Marek; Lipkin, Harry J; Rosner, Jonathan L
2007-01-01
The recent observation by CDF of Sigma_b^{+-} (uub and ddb) baryons within 2 MeV of the predicted Sigma_b - Lambda_b splitting has provided strong confirmation for the theoretical approach based on modeling the color hyperfine interaction. We now apply this approach to predict the masses of the Xi_b family of baryons with quark content usb and dsb - the ground state Xi_b at 5790 to 5800 MeV, and the excited states Xi_b^' and Xi_b^*. The main source of uncertainty is the method used to estimate the mass difference m_b - m_c from known hadrons. We verify that corrections due to the details of the interquark potential and to Xi_b-Xi_b^' mixing are small.
Do Baryons Alter the Halos of Low Surface Brightness Galaxies?
de Naray, Rachel Kuzio
2011-01-01
High-quality observations of dark matter-dominated low surface brightness (LSB) galaxies indicate that, in contrast to the triaxial, centrally-concentrated cuspy halos formed in collisionless simulations of halo assembly, these galaxies reside in round, roughly constant density cored halos. In order to reconcile these data with galaxy formation in the context of LCDM, processes that alter the shape and density structure of the inner halo are required. We compile observational properties of LSB galaxies to evaluate the plausibility that a previously higher baryonic mass content and feedback from star formation can modify the dark matter halos of these galaxies. We also compare the properties of bulgeless disk galaxies formed in recent simulations to the LSB galaxy sample. We find that observational constraints on LSB galaxy star formation histories, structure, and kinematics make it difficult for baryonic physics to sphericalize and decrease the central density of the dark matter halos of LSB galaxies.
A Skyrme-type proposal for baryonic matter
Adam, C; Wereszczynski, A
2010-01-01
The Skyrme model is a low-energy effective field theory for QCD, where the baryons emerge as soliton solutions. It is, however, difficult within the standard Skyrme model to reproduce the almost exact linear growth of the nuclear masses with the baryon number (topological charge), due to the lack of a Bogomolny bound in this model, which has also hindered analytical progress. Here we identify a submodel within the Skyrme-type low energy effective action which does have a Bogomolny bound and exact solutions, and therefore reproduces the nuclear masses with a high precision (better than one percent). We propose that the terms of the submodel should be included in a low-energy effective field theory description of nuclei and probably even give the main contribution to their masses.
Dark Galaxies and Lost Baryons (IAU S244)
Davies, Jonathan I.; Disney, Michael J.
2008-05-01
Preface; Conference prelims; The HI that barked in the night M. J. Disney; The detection of dark galaxies in blind HI surveys J. I. Davies; Red haloes of galaxies - reservoirs of baryonic dark matter? E. Zackrisson, N. Bergvall, C. Flynn, G. Ostlin, G. Micheva and B. Baldwell; Constraints on dark and visible mass in galaxies from strong gravitational lensing S. Dye and S. Warren; Lost baryons at low redshift S. Mathur, F. Nicastro and R. Williams; Observed properties of dark matter on small spatial scales R. Wyse and G. Gilmore; The mass distribution in spiral galaxies P. Salucci; Connecting lost baryons and dark galaxies via QSO absorption lines T. Tripp; ALFALFA: HI cosmology in the local universe R. Giovanelli; The ALFALFA search for (almost) dark galaxies across the HI mass function M. Haynes; HI clouds detected towards Virgo with the Arecibo Legacy Fast ALFA Survey B. Kent; Cosmic variance in the HI mass function S. Schneider; The Arecibo Galaxy Environments Survey - potential for finding dark galaxies and results so far R. Minchin et al.; Free-floating HI clouds in the M81 group E. Brinks, F. Walter and E. Skillman; Where are the stars in dark galaxies J. Rosenberg, J. Salzer and J. Cannon; The halo by halo missing baryon problem S. McGaugh; The local void is really empty R. Tully; Voids in the local volume: a limit on appearance of a galaxy in a dark matter halo A. Tikhonov and A. Klypin; Dim baryons in the cosmic web C. Impey; A census of baryons in galaxy clusters and groups A. Gonzalez, D. Zaritsky and A. Zabludo; Statistical properties of the intercluster light from SDSS image stacking S. Zibetti; QSO strong gravitational lensing and the detection of dark halos A. Maccio; Strong gravitational lensing: bright galaxies and lost dark-matter L. Koopmans; Mapping the distribution of luminous and dark matter in strong lensing galaxies I. Ferreras, P. Saha, L. Williams and S. Burles; Tidal debris posing as dark galaxies P. Duc, F. Bournaud and E. Brinks
Generalized polarizabilities of the nucleon in baryon chiral perturbation theory
Lensky, Vadim; Pascalutsa, Vladimir; Vanderhaeghen, Marc
2017-02-01
The nucleon generalized polarizabilities (GPs), probed in virtual Compton scattering (VCS), describe the spatial distribution of the polarization density in a nucleon. They are accessed experimentally via the process of electron-proton bremsstrahlung (ep→ epγ ) at electron-beam facilities, such as MIT-Bates, CEBAF (Jefferson Lab), and MAMI (Mainz). We present the calculation of the nucleon GPs and VCS observables at next-to-leading order in baryon chiral perturbation theory (Bχ PT), and confront the results with the empirical information. At this order our results are predictions, in the sense that all the parameters are well known from elsewhere. Within the relatively large uncertainties of our calculation we find good agreement with the experimental observations of VCS and the empirical extractions of the GPs. We find large discrepancies with previous chiral calculations - all done in heavy-baryon χ PT (HBχ PT) - and discuss the differences between Bχ PT and HBχ PT responsible for these discrepancies.
On the Statistics of Baryon Correlation Functions in Lattice QCD
Wagman, Michael L
2016-01-01
A systematic analysis of the structure of single-baryon correlation functions calculated with lattice QCD is performed, with a particular focus on characterizing the structure of the noise associated with quantum fluctuations. The signal-to-noise problem in these correlation functions is shown, as long suspected, to result from a sign problem. The log-magnitude and complex phase are found to be approximately described by normal and wrapped normal distributions respectively. Properties of circular statistics are used to understand the emergence of a late time noise region where standard energy measurements are unreliable. Power-law tails in the distribution of baryon correlation functions, associated with stable distributions and "Levy flights", are found to play a central role in their time evolution. A new method of analyzing correlation functions is considered for which the signal-to-noise ratio of energy measurements is constant at late times, rather than degrading exponentially; this permits a reliable ex...
Baryon asymmetry of the universe and new neutrino states
Hollenberg, Sebastian; Schalla, Dario
2011-01-01
The presence of additional neutrino states with masses in the GeV range is allowed by electro-weak precision observables. However, these additional states can lead to lepton number violating interactions which potentially can wash out considerably any GUT scale generated or elsewise pre-existing baryon asymmetry. We discuss the resulting bounds on neutrino parameters and find that - unless the baryon asymmetry is created at or below the electroweak scale or in some flavor which is decoupled from interactions to the new neutrino states - these have to be pseudo-Dirac with mass splittings between the right-handed and left-handed states of less than about ten keV.
Baryon number fluctuations at finite temperature and density
Fu, Wei-jie; Rennecke, Fabian; Schaefer, Bernd-Jochen
2016-01-01
We investigate baryon number fluctuations for finite temperature and density in two-flavor QCD. This is done within a QCD-improved low-energy effective theory in an extension of the approach put forward in [1,2]. In the present work we aim at improving the predictive power of this approach for large temperatures and density, that is, for small collision energies. This is achieved by taking into account the full frequency dependence of the quark dispersion. This ensures the necessary Silver Blaze property of finite density QCD for the first time, which so far was only implemented approximately. Moreover, we show that Polyakov loop fluctuations have a sizeable impact at large temperatures and density. The results for the kurtosis of baryon number fluctuations are compared to previous effective theory results, lattice results and recent experimental data from STAR.
Connecting the Baryons: Multiwavelength Data for SKA HI Surveys
Meyer, Martin; Obreschkow, Danail; Driver, Simon; Staveley-Smith, Lister; Zwaan, Martin
2015-01-01
The science achievable with SKA HI surveys will be greatly increased through the combination of HI data with that at other wavelengths. These multiwavelength datasets will enable studies to move beyond an understanding of HI gas in isolation to instead understand HI as an integral part of the highly complex baryonic processes that drive galaxy evolution. As they evolve, galaxies experience a host of environmental and feedback influences, many of which can radically impact their gas content. Important processes include: accretion (hot and cold mode, mergers), depletion (star formation, galactic winds, AGN), phase changes (ionised/atomic/molecular), and environmental effects (ram pressure stripping, tidal effects, strangulation). Governing all of these to various extents is the underlying dark matter distribution. In turn, the result of these processes can significantly alter the baryonic states in which material is finally observed (stellar populations, dust, chemistry) and its morphology (galaxy type, bulge/d...
Baryon Number Fluctuations in Quasi-particle Model
Zhao, Ameng; Zong, Hongshi
2016-01-01
Baryon number fluctuations are sensitive to the QCD phase transition and QCD critical point. According to the Feynman rules of finite-temperature field theory, we calculated various order moments and cumulants of the baryon number distributions in the quasi-particle model of quark gluon plasma. Furthermore, we compared our results with the experimental data measured by the STAR experiment at RHIC. It is found that the experimental data can be well described by the model for the colliding energies above 30 GeV and show large discrepancies at low energies. It can put new constraint on qQGP model and also provide a baseline for the QCD critical point search in heavy-ion collisions at low energies.
Baryon properties in meson mediums from lattice QCD
Nicholson, Amy N
2013-01-01
We present results for the ground-state mass shifts of octet baryons due to the presence of a medium of pions or kaons from a lattice QCD calculation performed at a single value of the quark mass, corresponding to a pion mass of $m_\\pi$ ~ 390 MeV, and a spatial volume V ~ (4fm)^3. We use a canonical approach in which correlators are formed using a single baryon propagator and a fixed number of meson propagators, up to n=9. From the ground-state energies we calculate two- and three-body interaction parameters. We also extract combinations of low-energy constants by comparing our results to tree level chiral perturbation theory at non-zero isospin/kaon chemical potential.
Baryon to meson transition distribution amplitudes and their spectral representation
Pire, Bernard; Szymanowski, Lech
2011-01-01
We consider the problem of construction of a spectral representation for nucleon to meson transition distribution amplitudes (TDAs), non-diagonal matrix elements of nonlocal three quark light-cone operators between a nucleon and a meson states. We introduce the notion of quadruple distributions and generalize Radyshkin's factorized Ansatz for this issue. Modelling of baryon to meson TDAs in the complete domain of their definition opens the way to quantitative estimates of cross-sections for various hard exclusive reactions.
Variational Study of Weakly Coupled Triply Heavy Baryons
Jia, Y
2006-01-01
Baryons made of three heavy quarks become weakly coupled, when all the quarks are sufficiently heavy such that the typical momentum transfer is much larger than Lambda_QCD. We use variational method to estimate masses of the lowest-lying bcc, ccc, bbb and bbc states by assuming they are Coulomb bound states. Our predictions for these states are systematically lower than those made long ago by Bjorken.
First Observation of a Family of Double-Charm Baryons
Russ, J S
2002-01-01
The SELEX experiment (E781) at Fermilab has candidates for high mass states decaying to Lambda_c+ K- pi+ and Lambda_c+ K- pi+ pi+, Cabibbo-allowed decay modes of doubly-charmed baryons Xi_cc+ and Xi_cc++. The masses are consistent with theoretical considerations, but the spectroscopy is surprising. Limited lifetime information suggests that tau_{Xi_cc++} \\sim tau_{Xi_cc+}.
Baryon currents in the C-broken phase of QCD
Lucini, B; Pica, C
2007-01-01
In a space with some sufficiently small compact dimension (with non-trivial cycles) and with periodic boundary conditions for the fermions, the charge conjugation (C), spatial parity (P), time reversal (T) and CPT symmetries are spontaneously broken in QCD. We have investigated what are the physical consequences of the breaking of these discrete symmetries, that is what local observables can be used to detect it. We show that the breaking induces the generation of baryon currents, propagating along the compact dimensions.
The baryon number two system in the Chiral Soliton Model
Sarti, Valentina Mantovani; Vento, Vicente; Park, Byung-Yoon
2012-01-01
We study the interaction between two B = 1 states in a Chiral Soliton Model where baryons are described as non-topological solitons. By using the hedgehog solution for the B = 1 states we construct three possible B = 2 configurations to analyze the role of the relative orientation of the hedgehog quills in the dynamics. The strong dependence of the intersoliton interaction on these relative orientations reveals that studies of dense hadronic matter using this model should take into account their implications.
Model dependence of baryon decay enhancement by cosmic strings
Fewster, C J
1993-01-01
Cosmic strings arising from GUTs can catalyse baryon decay processes with strong interaction cross sections. We examine the mechanism by which the cross section is enhanced and find that it depends strongly on the details of the distribution of gauge fields within the string core. We propose a calculational scheme for estimating wavefunction amplification factors and also a physical understanding of the nature of the enhancement process.
Baryon magnetic moments in the background field method
Lee, F X; Zhou, L; Wilcox, W
2005-01-01
We present a calculation of the magnetic moments for the baryon octet and decuplet using the background-field method and standard Wilson gauge and fermion actions in the quenched approximation of lattice QCD. Progressively smaller static magnetic fields are introduced on a $24^4$ lattice at beta=6.0 and the pion mass is probed down to about 500 MeV. Magnetic moments are extracted from the linear response of the masses to the background field.
Baryon Number Violating Scalar Diquarks at the LHC
Baldes, Iason; Volkas, Raymond R
2011-01-01
Baryon number violating (BNV) processes are heavily constrained by experiments searching for nucleon decay and neutron-antineutron oscillations. If the baryon number violation occurs via the third generation quarks, however, we may be able to avoid the nucleon stability constraints, thus making such BNV interactions accessible at the LHC. In this paper we study a specific class of BNV extensions of the standard model (SM) involving diquark and leptoquark scalars. After an introduction to these models we study one promising extension in detail, being interested in particles with mass of O(TeV). We calculate limits on the masses and couplings from neutron-antineutron oscillations and dineutron decay for couplings to first and third generation quarks. We explore the possible consequences of such a model on the matter-antimatter asymmetry. We shall see that for models which break the global baryon minus lepton number symmetry, (B-L), the most stringent constraints come from the need to preserve a matter-antimatte...
A Baryonic Solution to the Missing Satellites Problem
Energy Technology Data Exchange (ETDEWEB)
Brooks, Alyson M.; Kuhlen, Michael; Zolotov, Adi; Hooper, Dan
2013-03-01
It has been demonstrated that the inclusion of baryonic physics can alter the dark matter densities in the centers of low-mass galaxies, making the central dark matter slope more shallow than predicted in pure cold dark matter simulations. This flattening of the dark matter profile can occur in the most luminous subhalos around Milky Way mass galaxies. Zolotov et al. have suggested a correction to be applied to the central masses of dark matter-only satellites in order to mimic the affect of (1) the flattening of the dark matter cusp due to supernova feedback in luminous satellites and (2) enhanced tidal stripping due to the presence of a baryonic disk. In this paper, we apply this correction to the z = 0 subhalo masses from the high resolution, dark matter-only Via Lactea II (VL2) simulation, and find that the number of massive subhalos is dramatically reduced. After adopting a stellar mass to halo mass relationship for the VL2 halos, and identifying subhalos that are (1) likely to be destroyed by stripping and (2) likely to have star formation suppressed by photo-heating, we find that the number of massive, luminous satellites around a Milky Way mass galaxy is in agreement with the number of observed satellites around the Milky Way or M31. We conclude that baryonic processes have the potential to solve the missing satellites problem
Possible Deuteron-like Molecular States Composed of Heavy Baryons
Lee, Ning; Chen, Xiao-Lin; Zhu, Shi-Lin
2011-01-01
We perform a systematic study of the possible loosely bound states composed of two charmed baryons or a charmed baryon and an anti-charmed baryon within the framework of the one boson exchange (OBE) model. We consider not only the $\\pi$ exchange but also the $\\eta$, $\\rho$, $\\omega$, $\\phi$ and $\\sigma$ exchanges. The $S-D$ mixing effects for the spin-triplets are also taken into account. With the derived effective potentials, we calculate the binding energies and root-mean-square (RMS) radii for the systems $\\Lambda_c\\Lambda_c(\\bar{\\Lambda}_c)$, $\\Xi_c\\Xi_c(\\bar{\\Xi}_c)$, $\\Sigma_c\\Sigma_c(\\bar{\\Sigma}_c)$, $\\Xi_c^\\prime\\Xi_c^\\prime(\\bar{\\Xi}_c^\\prime)$ and $\\Omega_c\\Omega_c(\\bar{\\Omega}_c)$. Our numerical results indicate that: (1) the H-dibaryon-like state $\\Lambda_c\\Lambda_c$ does not exist; (2) there may exist four loosely bound deuteron-like states $\\Xi_c\\Xi_c$ and $\\Xi_c^\\prime\\Xi_c^\\prime$ with small binding energies and large RMS radii.
Baryons as relativistic three-quark bound states
Eichmann, Gernot; Sanchis-Alepuz, Hèlios; Williams, Richard; Alkofer, Reinhard; Fischer, Christian S.
2016-11-01
We review the spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD. The composite nature of baryons results in a rich excitation spectrum, whilst leading to highly non-trivial structural properties explored by the coupling to external (electromagnetic and other) currents. Both present many unsolved problems despite decades of experimental and theoretical research. We discuss the progress in these fields from a theoretical perspective, focusing on nonperturbative QCD as encoded in the functional approach via Dyson-Schwinger and Bethe-Salpeter equations. We give a systematic overview as to how results are obtained in this framework and explain technical connections to lattice QCD. We also discuss the mutual relations to the quark model, which still serves as a reference to distinguish 'expected' from 'unexpected' physics. We confront recent results on the spectrum of non-strange and strange baryons, their form factors and the issues of two-photon processes and Compton scattering determined in the Dyson-Schwinger framework with those of lattice QCD and the available experimental data. The general aim is to identify the underlying physical mechanisms behind the plethora of observable phenomena in terms of the underlying quark and gluon degrees of freedom.
Measurement of matter-antimatter differences in beauty baryon decays
Aaij, Roel; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baszczyk, Mateusz; Batozskaya, Varvara; Batsukh, Baasansuren; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Bird, Thomas; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chobanova, Veronika; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Dall'Occo, Elena; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dungs, Kevin; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Déléage, Nicolas; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fay, Robert; Fazzini, Davide; Ferguson, Dianne; Fernandez Albor, Victor; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Furfaro, Emiliano; Färber, Christian; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, V.V.; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Griffith, Peter; Grillo, Lucia; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hatch, Mark; He, Jibo; Head, Timothy; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hombach, Christoph; Hopchev, P H; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hussain, Nazim; Hutchcroft, David; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kecke, Matthieu; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Kozachuk, Anastasiia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Loh, David; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Monroy, Ignacio Alberto; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Mussini, Manuel; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavorima; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Toriello, Francis; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Vernet, Maxime; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhang, Yu; Zhelezov, Alexey; Zheng, Yangheng; Zhokhov, Anatoly; Zhu, Xianglei; Zhukov, Valery; Zucchelli, Stefano
2017-01-01
Differences in the behaviour of matter and antimatter have been observed in $K$ and $B$ meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP violation. Using data from the LHCb experiment at the Large Hadron Collider, a search is made for CP-violating asymmetries in the decay angle distributions of $\\Lambda_b^0$ baryons decaying to $p\\pi^-\\pi^+\\pi^-$ and $p \\pi^- K^+ K^-$ final states. These four-body hadronic decays are a promising place to search for sources of CP violation both within and beyond the Standard Model of particle physics. We find evidence for CP violation in $\\Lambda_b^0$ to $p\\pi^-\\pi^+\\pi^-$ decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for CP violation in the baryon sector.
Transitions of two baryons to the H dibaryon in nuclei
Farrar, Glennys R S; Farrar, Glennys R.; Zaharijas, Gabrijela
2003-01-01
We calculate the suppression in the rate at which two baryons in a nucleus (viz., nucleons or $\\Lambda$'s) convert to an H dibaryon, using an Isgur-Karl wavefunction for quarks in the baryons and H, and a Bethe-Goldstone wavefunction for the baryons in the nucleus. If $r_H \\lsi 1/3~ r_N$, we find $\\tau_{A_{\\Lambda\\Lambda}\\to A'_H}\\gsi \\tau_\\Lambda$ and the observation of $\\Lambda$ decays from double-$\\Lambda$ hypernuclei does not exclude the existence of the H. If $m_H < 2 m_p$, nuclei are unstable but have very long lifetimes. For reasonable values of $r_H$ and the nuclear wavefunction, the lifetime can be long enough to evade anticipated SuperK limits $\\tau_{A_{NN}\\to A'_H}\\gsi {\\rm few} 10^{29}$ yr, or short enough to be observed. An analysis of SuperK data to look for this possibility should be undertaken.
Baryon effects on void statistics in the EAGLE simulation
Paillas, Enrique; Padilla, Nelson; Tissera, Patricia; Helly, John; Schaller, Matthieu
2016-01-01
Cosmic voids are promising tools for cosmological tests due to their sensitivity to dark energy, modified gravity and alternative cosmological scenarios. Most previous studies in the literature of void properties use cosmological N-body simulations of dark matter (DM) particles that ignore the potential effect of baryonic physics. We analyse voids in the mass and subhalo density field in the EAGLE simulations, which follow the evolution of galaxies in a Lambda cold dark matter Universe with state-of-the-art subgrid models for baryonic processes. We study the effect of baryons on void statistics by comparing results with simulations that only follow the evolution of DM, but use the same initial conditions as EAGLE. When using the mass in the simulation, we find that a DM-only simulation produces 24 per cent more voids than a hydrodynamical one, but this difference comes mainly from voids with radii smaller than 5 Mpc. We do not find significant differences in the density profiles between voids in EAGLE and its...
Aspects Of Baryon Number As A U(1) Symmetry
Pawl, A E
2005-01-01
The non-observation of proton decay strongly suggests that baryon number is a global U(1) (phase rotation) symmetry of the low-energy effective Lagrangian of particle physics. In the first half of this thesis, we explore the surprisingly dramatic consequences of this U(1) symmetry for the Affleck-Dine model of baryogenesis. Affleck-Dine baryogenesis is a popular model for the creation of a matter-antimatter asymmetry which relys on setting a complex scalar field into phase rotation. The phase symmetry of the Lagrangian has all important effect oil the evolution of this scalar field. The baryon number symmetry need not be restricted to a global symmetry. There is growing evidence from string theory, in fact, that global U(1) symmetries must have a gauge origin. In the second half of this thesis, we consider the details of how two different approaches to breaking a, gauged U(1) baryon symmetry would function in a universe with a low Planck scale. A universe with a low Planck scale (Mpl ∼ 103 GeV) has r...
Topics on heavy baryon chiral perturbation theory in the large N_c limit
Flores-Mendieta, R
2002-01-01
We compute nonanalytical pion-loop corrections to baryon masses in a combined expansion in chiral symmetry breaking and 1/N_c, where N_c is the number of colors. Specifically, we compute flavor-27 baryon mass splittings at leading order in chiral perturbation theory. Our results, at the physical value N_c=3, are compared with the expressions obtained in heavy baryon chiral perturbation theory with no 1/N_c expansion.
Baryon stopping in the color glass condensate formalism: A phenomenological study
Durães, F. O.; Giannini, A. V.; Gonçalves, V. P.; Navarra, F. S.
2014-03-01
The net-baryon production at forward rapidities is investigated considering the color glass condensate formalism. We assume that at large energies the coherence of the projectile quarks is lost and that the leading baryon production mechanism changes from recombination to independent fragmentation. The phenomenological implications for net-baryon production in pp /pA/AA collisions are analyzed and predictions for Large Hadron Collider energies are presented.
Electromagnetic form factors of the baryon octet in the perturbative chiral quark model
Cheedket, S; Gutsche, T; Faessler, A; Pumsa-ard, K; Yan, Y; Gutsche, Th.; Faessler, Amand
2002-01-01
We apply the perturbative chiral quark model at one loop to analyze the electromagnetic form factors of the baryon octet. The analytic expressions for baryon form factors, which are given in terms of fundamental parameters of low-energy pion-nucleon physics(weak pion decay constant, axial nucleon coupling, strong pion-nucleon form factor), and the numerical results for baryon magnetic moments, charge and magnetic radii are presented. Our results are in good agreement with experimental data.
Magnetic moments of $J^P = {3\\over 2}^-$ baryons in QCD
Aliev, T M
2014-01-01
The magnetic moments of the low lying, negative parity, spin-3/2 baryons are calculated within the light cone QCD sum rules method. The contributions coming from the positive parity, spin-3/2 baryons, as well as from the positive and negative parity spin-1/2 baryons are eliminated by constructing combinations of various invariant amplitudes corresponding to the coefficients of the different Lorentz structures.
Institute of Scientific and Technical Information of China (English)
李双; 冯笙琴
2012-01-01
The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. The net-baryon distributions, nuclear stopping power and gluon saturation features in the SPS and RHIC energy regions are investigated by taking advantage of the gluon saturation model with geometric scaling. Predications are made for the net-baryon rapidity distributions, mean rapidity loss and gluon saturation features in central Pb ＋ Pb collisions at LHC.
Net baryon density in Au+Au collisions at the Relativistic Heavy Ion Collider
Bass, S A; Srivastava, D K; Bass, Steffen A.; Müller, Berndt; Srivastava, Dinesh K.
2003-01-01
We calculate the net baryon rapidity distribution in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) in the framework of the Parton Cascade Model (PCM). Parton rescattering and fragmentation leads to a substantial increase in the net baryon density at mid-rapidity over the density produced by initial primary parton-parton scatterings. The PCM is able to describe the measured net baryon density at RHIC.
Phenomenology of the Heavy Flavored spin 3/2 Baryons in Light Cone QCD
Aliev, T M; Özpineci, A
2008-01-01
Motivated by the results of the recent experimental discoveries for charm and bottom baryons, the masses and magnetic moments of the heavy baryons with $J^P=3/2^+$ containing a single heavy quark are studied within light cone QCD sum rules method. Our results on the masses of heavy baryons are in good agreement with predictions of other approaches, as well as with the existing experimental data.
Baryon stopping in the Color Glass Condensate formalism: A phenomenological study
Duraes, F O; Goncalves, V P; Navarra, F S
2014-01-01
The net-baryon production at forward rapidities is investigated considering the Color Glass Condensate formalism. We assume that at large energies the coherence of the projectile quarks is lost and that the leading baryon production mechanism changes from recombination to independent fragmentation. The phenomenological implications for net-baryon production in $pp/pA/AA$ collisions are analysed and predictions for LHC energies are presented.
RH Sneutrino Condensate CDM and the Baryon-to-Dark Matter Ratio
McDonald, John
2007-01-01
The similarity of the observed mass densities of baryons and cold dark matter may be a sign they have a related origin. The baryon-to-dark matter ratio can be understood in the MSSM with right-handed (RH) neutrinos if CDM is due to a d = 4 flat direction condensate of very weakly coupled RH sneutrino LSPs and the baryon asymmetry is generated by Affleck-Dine leptogenesis along a d = 4 (H_{u}L)^2 flat direction. Observable signatures of the model include CDM and baryon isocurvature perturbations and distinctive long-lived NLSP phenomenology.
Ground state heavy baryon production in a relativistic quark-diquark model
Nobary, M A Gomshi
2007-01-01
We use current-current interaction to calculate the fragmentation functions to describe the production of spin-1/2, spin-1/2$'$ and spin-3/2 baryons with massive constituents in a relativistic quark-diquark model. Our results are in their analytic forms and are applicable for singly, doubly and triply heavy baryons. We discuss the production of $\\Omega_{bbc}$, $\\Omega_{bcc}$ and $\\Omega_{ccc}$ baryons in some detail. The results are satisfactorily compared with those obtained for triply heavy baryons calculated in a perturbative regime within reasonable values of the parameters involved.
Koshkarev, Sergey; Anikeev, Vladimir
2017-02-01
The high production rate and > 0.33 of the doubly charmed baryons measured by the SELEX experiment is not amenable to perturbative QCD analysis. In this paper we calculate the production of the doubly heavy baryons with the double intrinsic charm Fock states whose existence is rigorously predicted by QCD. The production rate and the longitudinal momentum distribution are both reproduced. We also show that the production rates of the doubly charmed baryons and double J / ψ production observed by NA3 collaboration are comparable. Recent experimental results are reviewed. The production cross section of the doubly charmed baryons at a fixed-target experiment at the LHC is presented.
Search for exotic baryons in double radiative capture on pionic hydrogen
Energy Technology Data Exchange (ETDEWEB)
Zolnierczuk, P.A. [University of Kentucky, Lexington, KY 40506 (United States); Armstrong, D.S. [College of William and Mary, Williamsburg, VA 23187 (United States); Christy, E. [University of Kentucky, Lexington, KY 40506 (United States); Clark, J.H.D. [College of William and Mary, Williamsburg, VA 23187 (United States); Gorringe, T.P. [University of Kentucky, Lexington, KY 40506 (United States)]. E-mail: gorringe@server1.pa.uky.edu; Hasinoff, M.D. [University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Kovash, M.A. [University of Kentucky, Lexington, KY 40506 (United States); Tripathi, S. [University of Kentucky, Lexington, KY 40506 (United States); Wright, D.H. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)
2004-09-09
We report a search for low-lying exotic baryons via double radiative capture on pionic hydrogen. The data were collected at the TRIUMF cyclotron using the RMC spectrometer by detecting gamma-ray pairs from pion stops in liquid hydrogen. We found no evidence to support an earlier claim for exotic baryons of masses 1004 and 1044 MeV/c2, and set upper limits on exotic baryon mediated capture of 3x10-6 and 4x10-6, respectively. We also obtained bounds on the couplings between exotic baryons and ordinary nucleons.
Bulk viscosity for pion and nucleon thermal fluctuation in the hadron resonance gas model
Ghosh, Sabyasachi; Mohanty, Bedangdas
2016-01-01
We have calculated microscopically bulk viscosity of hadronic matter, where equilibrium thermodynamics for all hadrons in medium are described by Hadron Resonance Gas (HRG) model. Considering pions and nucleons as abundant medium constituents, we have calculated their thermal widths, which inversely control the strength of bulk viscosities for respective components and represent their in-medium scattering probabilities with other mesonic and baryonic resonances, present in the medium. Our calculations show that bulk viscosity increases with both temperature and baryon chemical potential, whereas viscosity to entropy density ratio decreases with temperature and with baryon chemical potential, the ratio increases first and then decreases. The decreasing nature of the ratio with temperature is observed in most of the earlier investigations with few exceptions. We find that the temperature dependence of bulk viscosity crucially depends on the structure of the relaxation time. Along the chemical freeze-out line in...
Review on dynamically generated resonances
Oset, E; Nicmorus, D; Geng, L S; Gonzalez, P; Vijande, J; Sarkar, S; Sun, Bao Xi; Vacas, M J Vicente; Ramos, A; Garzon, E J; Torres, A Martinez; Khemchandani, K
2010-01-01
We present recent results on the vector meson-vector meson and vector meson-baryon interaction using a unitary approach based on the hidden-gauge Lagrangians. For the vector-vector case we find that 11 states get dynamically generated, corresponding to poles of the scattering matrices on the second Riemann sheet. In the vector-baryon sector we also find 9 states dynamically generated from the vector-baryon octet interaction and 10 from the vector-baryon decuplet interaction. We also report on baryon states found from the interaction of two mesons and a baryon.
Future Perspectives on Baryon Form Factor Measurements with BES III
Schönning, Karin; Li, Cui
2017-03-01
The electromagnetic structure of hadrons, parameterised in terms of electromagnetic form factors, EMFF's, provide a key to the strong interaction. Nucleon EMFF's have been studied rigorously for more than 60 years but the new techniques and larger data samples available at modern facilities have given rise to a renewed interest for the field. Recently, the access to hyperon structure by hyperon time-like EMFF provides an additional dimension. The BEijing Spectrometer (BES III) at the Beijing Electron Positron Collider (BEPC-II) in China is the only running experiment where time-like baryon EMFF's can be studied in the e+e- → BB̅ reaction. The BES III detector is an excellent tool for baryon form factor measurements thanks to its near 4π coverage, precise tracking, PID and calorimetry. All hyperons in the SU(3) spin 1/2 octet and spin 3/2 decuplet are energetically accessible within the BEPC-II energy range. Recent data on proton and Λ hyperon form factors will be presented. Furthermore, a world-leading data sample was collected in 2014-2015 for precision measurements of baryon form factors. In particular, the data will enable a measurement of the relative phase between the electric and the magnetic form factors for Λ and Λc+ and hyperons. The modulus of the phase can be extracted from the hyperon polarisation, which in turn is experimentally accessible via the weak, parity violating decay. Furthermore, from the spin correlation between the outgoing hyperon and antihyperon, the sign of the phase can be extracted. This means that the time-like form factors can be completely determined for the first time. The methods will be outlined and the prospects of the BES III form factor measurements will be given. We will also present a planned upgrade of the BES III detector which is expected to improve future form factor measurements.
Exotic baryon multiplets at large number of colours
Diakonov, D; Diakonov, Dmitri; Petrov, Victor
2003-01-01
We generalize the usual octet, decuplet and exotic antidecuplet and higher baryon multiplets to any number of colours Nc. We show that the multiplets fall into a sequence of bands with O(1/Nc) splittings inside the band and O(1) splittings between the bands characterized by "exoticness", that is the number of extra quark-antiquark pairs needed to compose the multiplet. Unless exoticness becomes very large, all multiplets can be reliably described at large Nc as collective rotational excitations of a chiral soliton.
Observation and mass measurement of the baryon Xib-.
Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; 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; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, 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; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; 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; Dörr, C; 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, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; 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; Group, R 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; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, 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; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; 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; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; 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; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; 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; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; 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; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; 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; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; 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; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; 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; Zhou, J; Zucchelli, S
2007-08-03
We report the observation and measurement of the mass of the bottom, strange baryon Xi(b)- through the decay chain Xi(b)- -->J/psiXi-, where J/psi-->mu+mu-, Xi- -->Lambdapi-, and Lambda-->ppi-. A signal is observed whose probability of arising from a background fluctuation is 6.6 x 10(-15), or 7.7 Gaussian standard deviations. The Xi(b)- mass is measured to be 5792.9+/-2.5(stat) +/- 1.7(syst) MeV/c2.
Helioseismology with long-range dark matter-baryon interactions
DEFF Research Database (Denmark)
Lopes, I.; Panci, Paolo; Silk, J.
2014-01-01
Assuming the existence of a primordial asymmetry in the dark sector, we study how long-range dark matter (DM)-baryon interactions, induced by the kinetic mixing of a new U(1) gauge boson and a photon, affect the evolution of the Sun and, in turn, the sound speed the profile obtained from...... the agreement between the best solar model and the helioseismic data without being excluded by direct detection experiments. In particular, the LUX detector will soon be able to either constrain or confirm our best-fit solar model in the presence of a dark sector with long-range interactions that reconcile...
First Observation of the Doubly Charmed Baryon Xi_cc^+
Mattson, M E
2002-01-01
We observe a signal for the doubly charmed baryon Xi_cc^+ in the charged decay mode Xi_cc^+ --> Lambda_c^+ K- pi+ in data from SELEX, the charm hadro-production experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1 \\pm 0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is (3519 \\pm 1) MeV/c^2. The Gaussian mass width of this state is 3MeV/c^2, consistent with resolution; its lifetime is less than 33fsec at 90% confidence.
Light-cone sum rule approach for Baryon form factors
Offen, Nils
2016-01-01
We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations.
Discrete Symmetry Transformation of Baryon- and Lepton-Nonconserving Processes
Jafari, Ehsan
2016-01-01
In this paper we consider discrete symmetry (C, P, T and CP) transformations of baryon- and lepton-nonconserving processes. According to our calculation it is not possible to definite exact discrete symmetry transformation for any operator which breaks $B-L$ and changes the number of fundamental fermions between initial and final states. In order to count the net change of fundamental fermions between initial and final states, $F$ number has been introduced. On the other hand from theoretical point of view we are not able to label operators which break $B-L$ and violate F number as $-even$ or $-odd$ under the effect of discrete symmetries.
Light-Cone Sum Rule Approach for Baryon Form Factors
Offen, Nils
2016-10-01
We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations.
Measurement of the mass of the $\\Lambda_{b}$ baryon
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; 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; 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
In a data sample of four million hadronic \\Z\\ decays collected with the ALEPH detector at LEP, four $\\Lambda_b$ baryon candidates are exclusively reconstructed in the $\\Lambda_b \\rightarrow \\Lambda_c^+ \\pi^-$ channel, with the $\\Lambda_c^+$ decaying into $pK^-\\pi^+$, $p\\bar{K^0}$, or $\\Lambda\\pi^+\\pi^+\\pi^-$. The probability of the observed signal to be due to a background fluctuation is estimated to be $4.2 \\times 10^{-4}$. The mass of the $\\Lambda_b$ is measured to be $5614 \\pm 21 \\, (stat.) \\pm 4 \\, (syst.)~\\mevcc$. %$5614\\pm 21\\,(stat.) \\pm 4\\,(syst.) \\mevcc$.
Renormalization and applications of baryon distribution amplitudes QCD
Energy Technology Data Exchange (ETDEWEB)
Rohrwild, Juergen Holger
2009-07-17
Higher-twist effects are relevant for precision calculations of hard exclusive reactions. Furthermore, they reveal fine details of the hadron structure. In this work we construct an operator basis for arbitrary twist respecting the conformal symmetry of QCD (which is realized on 1-loop level). Using this basis the 1-loop renormalization kernels of twist 4 are constructed for baryon operators. The full spectrum of anomalous dimensions and the multiplicatively renormalizable operators is obtained. As an application of these results the radiative N{sup *}(1535) decay is discussed. Employing light-cone sum rule, the transition form factors can be directly related to the N{sup *} distribution amplitudes. (orig.)
Renormalization and applications of baryon distribution amplitudes in QCD
Energy Technology Data Exchange (ETDEWEB)
Rohrwild, Juergen Holger
2009-07-17
Higher-twist effects are relevant for precision calculations of hard exclusive reactions. Furthermore, they reveal fine details of the hadron structure. In this work we construct an operator basis for arbitrary twist respecting the conformal symmetry of QCD (which is realized on 1-loop level). Using this basis the 1-loop renormalization kernels of twist 4 are constructed for baryon operators. The full spectrum of anomalous dimensions and the multiplicatively renormalizable operators is obtained. As an application of these results the radiative N{sup *}(1535) decay is discussed. Employing light-cone sum rule, the transition form factors can be directly related to the N* distribution amplitudes. (orig.)
Strong decays of nonstrange q{sup 3} baryons
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico, D.F. (Mexico); Iachello, F. [Center for Theoretical Physics, Sloane Laboratory, Yale University, New Haven, Connecticut 06520-8120 (United States); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
1997-03-01
We study strong decays of nonstrange baryons by making use of the algebraic approach to hadron structure. Within this framework we derive closed expressions for decay widths in an elementary-meson emission model and use these to analyze the experimental data for N{sup {asterisk}}{r_arrow}N+{pi}, N{sup {asterisk}}{r_arrow}{Delta}+{pi}, N{sup {asterisk}}{r_arrow}N+{eta}, {Delta}{sup {asterisk}}{r_arrow}N+{pi}, {Delta}{sup {asterisk}}{r_arrow}{Delta}+{pi}, and {Delta}{sup {asterisk}}{r_arrow}{Delta}+{eta} decays. {copyright} {ital 1997} {ital The American Physical Society}
Lattice QCD for Baryon Rich Matter - Beyond Taylor Expansions
Bornyakov, V.; Boyda, D.; Goy, V.; Molochkov, A.; Nakamura, A.; Nikolaev, A.; Zakharov, V. I.
2016-12-01
We discuss our study for exploring the QCD phase diagram based on the lattice QCD. To go beyond the Taylor expansion and to reach higher density regions, we employ the canonical approach. In order to produce lattice data which meet experimental situation as much as possible, we propose a canonical approach with the charge and baryon number. We present our lattice QCD GPU code for this project which employs the clover improved Wilson fermions and Iwasaki gauge action to investigate pure imaginary chemical potential.
Chiral dynamics of baryons in the perturbative chiral quark model
Energy Technology Data Exchange (ETDEWEB)
Pumsa-ard, K.
2006-07-01
In this work we develop and apply variants of a perturbative chiral quark model (PCQM) to the study of baryonic properties dominantly in the low-energy region. In a first step we consider a noncovariant form of the PCQM, where confinement is modelled by a static, effective potential and chiral corrections are treated to second order, in line with similar chiral quark models. We apply the PCQM to the study of the electromagnetic form factors of the baryon octet. We focus in particular on the low-energy observables such as the magnetic moments, the charge and magnetic radii. In addition, the electromagnetic N-delta transition is also studied in the framework of the PCQM. In the chiral loop calculations we consider a quark propagator, which is restricted to the quark ground state, or in hadronic language to nucleon and delta intermediate states, for simplicity. We furthermore include the low-lying excited states to the quark propagator. In particular, the charge radius of the neutron and the transverse helicity amplitudes of the N-delta transition are considerably improved by this additional effect. In a next step we develop a manifestly Lorentz covariant version of the PCQM, where in addition higher order chiral corrections are included. The full chiral quark Lagrangian is motivated by and in analogy to the one of Chiral Perturbation Theory (ChPT). This Lagrangian contains a set of low energy constants (LECs), which are parameters encoding short distance effects and heavy degrees of freedom. We evaluate the chiral Lagrangian to order O(p{sup 4}) and to one loop to generate the dressing of the bare quark operators by pseudoscalar mesons. In addition we include the vector meson degrees of freedom in our study. Projection of the dressed quark operators on the baryonic level serves to calculate the relevant matrix elements. In a first application of this scheme, we resort to a parameterization of the valence quark form factors in the electromagnetic sector. Constraints
Observation and Mass Measurement of the Baryon $\\Xi^-_b$
Aaltonen, T; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bölla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, Yu; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, 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; Crescioli, F; Cuenca-Almenar, C; Cuevas-Maestro, J; Culbertson, R; Cully, J C; Da Ronco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; De Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, Mauro; Delli Paoli, F; 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; Dorr, C; 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, I; Fedorko, W T; Feild, R G; Feindt, M; Fernández, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; García, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gómez, G; Gómez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimarães 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; Hidas, D; Hill, C S; Hirschbuehl, D; Höcker, A; Holloway, 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; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; 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; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; 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; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; 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; Makhoul, K; Mäki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martinez-Ballarin, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtälä, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla-Fernández, P A; Mülmenstädt, J; Mukherjee, A; Müller, T; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Österberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, Aldo L; 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; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P B; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Salto, O; 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; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T G; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakian, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Söderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Saint-Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; Van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobuev, I P; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; 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; Zhou, J; Zucchelli, S
2007-01-01
We report the observation and measurement of the mass of the bottom, strange baryon $\\Xi^-_b$ through the decay chain $\\Xi^-_b \\to J/\\psi \\Xi^-$, where $J/\\psi \\to \\mu^+ \\mu^-$, $\\Xi^- \\to \\Lambda \\pi^-$, and $\\Lambda \\to p \\pi^-$. Evidence for observation is based on a signal whose probability of arising from the estimated background is $6.6 \\times 10^{-15}$, or 7.7 Gaussian standard deviations. The $\\Xi^-_b$ mass is measured to be $5792.9\\pm 2.5$ (stat.) $\\pm 1.7$ (syst.) MeV/$c^2$.
Baryon octet electromagnetic form factors in a confining NJL model
Directory of Open Access Journals (Sweden)
Manuel E. Carrillo-Serrano
2016-08-01
Full Text Available Electromagnetic form factors of the baryon octet are studied using a Nambu–Jona-Lasinio model which utilizes the proper-time regularization scheme to simulate aspects of colour confinement. In addition, the model also incorporates corrections to the dressed quarks from vector meson correlations in the t-channel and the pion cloud. Comparison with recent chiral extrapolations of lattice QCD results shows a remarkable level of consistency. For the charge radii we find the surprising result that rEp
A Precision Measurement of the Lambda_c Baryon Mass
Aubert, B; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Zhang, J; Zhang, L; Chen, A; Eckhart, E A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Spaan, B; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Nogowski, R; Otto, S; Petzold, A; Schott, G; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De, R; Sangro; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Marks, J; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Mohapatra, A K; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Pierini, M; Plaszczynski, S; Schune, M H; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, Erwin; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Touramanis, C; Cormack, C M; Di Lodovico, F; Brown, C L; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Simi, G; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai, F; Tehrani; Voena, C; Christ, S; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Graziani, G; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, J; Strube, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Martínez-Vidal, F; Panvini, R S; Banerjee, S W; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Pan, Y; Prepost, R; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H
2005-01-01
The $\\Lambda_c^+$ baryon mass is measured using $\\Lambda_c^+\\to\\Lambda K^0_S K^+$ and $\\Lambda_c^+\\to\\Sigma^0 K^0_S K^+$ decays reconstructed in 232 fb$^{-1}$ of data collected with the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ storage ring. The $\\Lambda_c^+$ mass is measured to be $2286.46\\pm0.14\\mathrm{MeV}/c^2$. The dominant systematic uncertainties arise from the amount of material in the tracking volume and from the magnetic field strength.
Baryon Acoustic Peak and the Squeezed Limit Bispectrum
Mirbabayi, Mehrdad; Zaldarriaga, Matias
2014-01-01
In the non-relativistic regime, pertinent to the large scale structure of the Universe, the leading effect of a long-wavelength perturbation $\\delta(\\lambda_L)$ on short distance physics is a uniform acceleration $\\propto \\lambda_L \\delta(\\lambda_L)$. Typically, this has no effect on statistical averages at equal time since a uniform acceleration results in a uniform translation -- a reasoning that has been formalized as a "consistency condition" on the cosmological correlation functions. This naive expectation fails in the presence of the baryon acoustic feature provided $\\lambda_L < \\ell_{\\rm BAO}$. We derive the squeezed limit of correlation functions in this regime.
Discovering baryon-number violating neutralino decays at the LHC.
Butterworth, Jonathan M; Ellis, John R; Raklev, Are R; Salam, Gavin P
2009-12-11
Recently there has been much interest in the use of single-jet mass and jet substructure to identify boosted particles decaying hadronically at the LHC. We develop these ideas to address the challenging case of a neutralino decaying to three quarks in models with baryonic violation of R parity. These decays have previously been found to be swamped by QCD backgrounds. We demonstrate for the first time that such a decay might be observed directly at the LHC with high significance, by exploiting characteristics of the scales at which its composite jet breaks up into subjets.
Theories relating baryon asymmetry and dark matter: a Mini review
Directory of Open Access Journals (Sweden)
Stefano eMorisi
2014-01-01
Full Text Available The nature of dark matter and the origin of the baryon asymmetry are two of the deepest mysteries of modern particle physics. In the absence of hints regarding a possible solution to these mysteries, many approaches have been developed to tackle them simultaneously { leading to very diverse and rich models}. We give a short review where we describe the general features of some of these models and an overview on the general problem. We also propose a diagrammatic notation to label the different models.
Unified description of light- and strange-baryon spectra
Glozman, L Ya; Varga, K; Wagenbrunn, R F
1998-01-01
We present a chiral constituent quark model for light and strange baryons providing a unified description of their ground states and excitation spectra. The model relies on constituent quarks and Goldstone bosons arising as effective degrees of freedom of low-energy QCD from the spontaneous breaking of chiral symmetry. The spectra of the three-quark systems are obtained from a precise variational solution of the Schrödinger equation with a semirelativistic Hamiltonian. The theoretical predictions are found in close agreement with experiment.
Strange meson-baryon interaction in hot and dense medium: recent progress for a road to GSI/FAIR
Cabrera, Daniel; Aichelin, Jörg; bratkovskaya, Elena
2015-01-01
We report recent results on the dynamics of strange hadrons in two-body reactions relevant for near-threshold production in heavy-ion collisions at GSI/FAIR and NICA-Dubna. In particular, $\\bar K N$ scattering in hot and dense nuclear matter is studied within a chiral unitary framework in coupled channels, setting up the starting point for implementations in microscopic off-shell transport approaches. We focus on the calculation of transition rates with special attention to the excitation of hyperon resonances and isospin effects. Additionally, we explore "unconventional" strangeness generation by meson-meson and meson-baryon interactions in connection with recent HADES observations of deep sub-threshold $\\phi$ and $\\Xi$ production.
Sadler, M. E.; Isenhower, L. D.; Spinka, H.; Comfort, J.; Clajus, M.; McDonald, S.; Moriwaki, T.; Nefkens, B. M. K.; Tippens, W. B.; Peterson, J.; Briscoe, W. J.; Papandreou, Z.; Efendiev, A.; Manley, D. M.; Abaev, V.; Bekrenev, V.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Starostin, A.; Batinic, M.; Marusic, A.; Slaus, I.; Supek, I.; Svarc, A.; Koetke, D.
1996-05-01
A comprehensive experimental program has recently been approved at the AGS at Brookhaven National Laboratory to measure absolute differential cross sections for π^- p and K^- p → neutrals in the momentum region 0.4 - 1.9 GeV/c. The SLAC Crystal Ball will be used as a multiphoton spectrometer to identify the various reaction channels by reconstructing the invariant mass of the γ rays produced from the decay of neutral mesons. The motivation for these measurements is to improve our understanding of the spectroscopy of baryons and hyperons. The isospin selectivity (e.g., for the reactions π^- p → η n and K^- p → π^o Λ) in populating certain resonances will be discussed.
Does the {sigma}(1580)((3)/(2)){sup -} resonance exist?
Energy Technology Data Exchange (ETDEWEB)
Olmsted, J.; Prakhov, S.; Manley, D.M.; Allgower, C.E.; Bekrenev, V.S.; Briscoe, W.J.; Clajus, M.; Comfort, J.R.; Craig, K.; Grosnick, D.; Isenhower, D.; Knecht, N.; Koetke, D.D.; Kozlenko, N.G.; Kruglov, S.; Kulbardis, A.A.; Lolos, G.; Lopatin, I.V.; Manweiler, R.; Marusic, A.; McDonald, S.; Nefkens, B.M.K.; Papandreou, Z.; Peaslee, D.C.; Phaisangittisakul, N.; Price, J.W.; Ramirez, A.F.; Sadler, M.; Shafi, A.; Spinka, H.; Stanislaus, T.D.S.; Starostin, A.; Staudenmaier, H.M.; Strakovsky, I.I.; Supek, I.; Tippens, W.B
2004-05-20
Precise new data for the reaction K{sup -}p{yields}{pi}{sup 0}{lambda} are presented in the c.m. energy range 1565 to 1600 MeV. Our analysis of these data sheds new light on claims for the {sigma}(1580)((3)/(2)){sup -} resonance, which (if it exists with the specified quantum numbers) must be an exotic baryon because of its very low mass. Our results show no evidence for this state.
Does the Sigma(1580)3/2- resonance exist?
Olmsted, J A; Manley, D M; Allgower, C E; Bekrenev, V S; Briscoe, W J; Clajus, M; Comfort, J R; Craig, K; Grosnick, D P; Isenhower, D; Knecht, N; Koetke, D D; Kozlenko, N G; Kruglov, S; Kulbardis, A A; Lolos, G J; Lopatin, I V; Manweiler, R; Marusic, A; McDonald, S; Nefkens, B M K; Papandreou, Z; Peaslee, D C; Phaisangittisakul, N; Price, J W; Ramírez, A F; Sadler, M E; Shafi, A; Spinka, H M; Stanislaus, T D S; Starostin, A S; Staudenmaier, H M; Strakovsky, I I; Supek, I; Tippens, W B; Tippens, and W.B.
2003-01-01
Precise new data for the reaction $K^- p \\to \\pi^0 \\Lambda$ are presented in the c.m. energy range 1565 to 1600 MeV. Our analysis of these data sheds new light on claims for the $\\Sigma(1580){3/2}^-$ resonance, which (if it exists with the specified quantum numbers) must be an exotic baryon because of its very low mass. Our results are decisive and show no evidence for this state.
Does the Σ(1580) {3}/{2}- resonance exist?
Olmsted, J.; Prakhov, S.; Manley, D. M.; Allgower, C. E.; Bekrenev, V. S.; Briscoe, W. J.; Clajus, M.; Comfort, J. R.; Craig, K.; Grosnick, D.; Isenhower, D.; Knecht, N.; Koetke, D. D.; Kozlenko, N. G.; Kruglov, S.; Kulbardis, A. A.; Lolos, G.; Lopatin, I. V.; Manweiler, R.; Marušić, A.; McDonald, S.; Nefkens, B. M. K.; Papandreou, Z.; Peaslee, D. C.; Phaisangittisakul, N.; Price, J. W.; Ramirez, A. F.; Sadler, M.; Shafi, A.; Spinka, H.; Stanislaus, T. D. S.; Starostin, A.; Staudenmaier, H. M.; Strakovsky, I. I.; Supek, I.; Tippens, W. B.; Crystal Ball Collaboration
2004-05-01
Precise new data for the reaction K-p→π0Λ are presented in the c.m. energy range 1565 to 1600 MeV. Our analysis of these data sheds new light on claims for the Σ(1580){3}/{2}- resonance, which (if it exists with the specified quantum numbers) must be an exotic baryon because of its very low mass. Our results show no evidence for this state.
Decays of negative parity non-strange baryons in the 1/Nc expansion
Energy Technology Data Exchange (ETDEWEB)
Jose L. Goity; Carlos L. Schat; Norberto Scoccola
2004-04-01
The decays of non-strange negative parity baryons via the emission of single {pi} and {eta} mesons are analyzed in the framework of the 1/N{sub c} expansion. A basis of spin-flavor operators is established to that order, and with this basis the different partial wave decay amplitudes are obtained. The unknown effective coefficients are determined by fitting to the S- and D-wave partial widths as provided by the PDG. A full set of relations between widths that result at the leading order, i.e. order N{sub c0}, is given and tested with the data. The rather large errors of the input partial widths, that result from the often discrepant results for the resonance parameters from different analyses of the data, lead to a rather good fit at the leading order N{sub c0}. The next to leading order fit fails for that reason to pin down with satisfactory accuracy the effective sub leading effective constants.
Electroweak interactions and dark baryons in the sextet BSM model with a composite Higgs particle
Fodor, Zoltan; Kuti, Julius; Mondal, Santanu; Nogradi, Daniel; Wong, Chik Him
2016-01-01
The Electroweak interactions of a strongly coupled gauge theory are discussed with outlook beyond the Standard Model (BSM) under global and gauge anomaly constraints. The theory is built on a minimal massless fermion doublet of the SU(2) BSM flavor group (bsm-flavor) with a confining gauge force at the TeV scale in the two-index symmetric (sextet) representation of the BSM SU(3) color gauge group (bsm-color). The intriguing possibility of near-conformal sextet gauge dynamics could lead to the minimal realization of the composite Higgs mechanism with a light $0^{++}$ scalar, far separated from strongly coupled resonances of the confining gauge force in the 2-3 TeV range, distinct from Higgsless Technicolor. In previous publications we have presented results for the meson spectrum of the theory, including the light composite scalar, perhaps the emergent Higgs impostor. Here we discuss the critically important role of the baryon spectrum in the sextet model investigating its compatibility with what we know about...
Calculable Cosmological CP Violation and Resonant Leptogenesis
Achelashvili, Avtandil
2016-01-01
Within the extension of MSSM by two right handed neutrinos, which masses are degenerate at tree level, we address the issue of leptogenesis. Investigating the quantum corrections in details, we show that the lepton asymmetry is induced at 1-loop level and decisive role is played by the tau lepton Yukawa coupling. On a concrete and predictive neutrino model, which enables to predict the CP violating $\\delta $ phase and relate it to the cosmological CP asymmetry, we demonstrate that the needed amount of the baryon asymmetry is generated via the resonant leptogenesis.
A first study of the semi-leptonic decay of the $\\Lambda_b$ baryon
Stella, N
1996-01-01
We present the preliminary results of the first Lattice study of the baryonic Isgur and Wise function obtained from the matrix element of the weak current between $\\Lambda$-baryon external states. Its dependence on the heavy and light quark masses is studied. Some result on the semi-leptonic decay
Excited State Mass spectra and Regge trajectories of Bottom Baryons in Hypercentral quark Model
Thakkar, Kaushal; Rai, Ajay Kumar; Vinodkumar, P C
2016-01-01
We present the mass spectra of excited states of singly heavy baryons consist of a bottom quark and light quarks (u, d and s). The QCD motivated hypercentral quark model is employed for the three body description of baryons. The form of confinement potential is hyper coloumb plus power potential with potential index $\
Evidence for non-analytic light quark mass dependence in the baryon spectrum
Walker-Loud, Andre
2011-01-01
Using precise lattice QCD computations of the baryon spectrum, we present the first direct evidence for the presence of contributions to the baryon masses which are non-analytic in the light quark masses; contributions which are often denoted "chiral logarithms". We isolate the poor convergence of SU(3) baryon chiral perturbation theory to the flavor-singlet mass combination. The flavor-octet baryon mass splittings, which are corrected by chiral logarithms at next to leading order in SU(3) chiral perturbation theory, yield baryon-pion axial coupling constants D, F, C and H consistent with QCD values; the first evidence of chiral logarithms in the baryon spectrum. The Gell-Mann--Okubo relation, a flavor-27 baryon mass splitting, which is dominated by chiral corrections from light quark masses, provides further evidence for the presence of non-analytic light quark mass dependence in the baryon spectrum; we simultaneously find the GMO relation to be inconsistent with the first few terms in a taylor expansion in ...
Analysis of the Triply Heavy Baryon States with QCD Sum Rules
Institute of Scientific and Technical Information of China (English)
WANG Zhi-Gang
2012-01-01
In this article, we study the (1/2)± and (3/2)± triply heavy baryon states in a systematic way by subtracting the contributions from the corresponding (1/2) and (3/2) triply heavy baryon states with the QCD sum rules, and make reasonable predictions for their masses.
Determination of the quark coupling strength $|V_{ub}|$ using baryonic decays
AUTHOR|(INSPIRE)INSPIRE-00392760
This thesis presents the first determination of $|V_{ub}|$ at a hadron collider and in a baryonic decay. The determination is made by measuring the ratio of branching fractions of the baryonic decays $\\Lambda^0_b \\to p \\mu^-\\overline{\