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
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.
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.
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.}
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.
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.
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.
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.
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.
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.
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.
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.
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...
Selected problems of baryons spectroscopy: chiral soliton versus quark models
Kopeliovich, Vladimir B
2008-01-01
Inconsistency between rigid rotator and bound state models at arbitrary number of colors, rigid rotator -- soft rotator dilemma and some other problems of baryon spectroscopy are discussed in the framework of the chiral soliton approach (CSA). Consequences of the comparison of CSA results with simple quark models are considered and the $1/N_c$ expansion for the effective strange antiquark mass is presented, as it follows from the CSA. Strong dependence of the effective strange antiquark mass on the SU(3) multiplet is required to fit the CSA predictions. The difference of `good' and `bad' diquark masses, which is about 100 Mev, is in reasonable agreement with other estimates. Multibaryons (hypernuclei) with strangeness are described and some states of interest are predicted within CSA as well.
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.
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_{...
Baryon Spectroscopy at ELSA and at MAMI - selected results
Directory of Open Access Journals (Sweden)
Krusche B.
2014-05-01
Full Text Available Spectroscopy of baryons and their excited states plays a key role for our understanding of the strong interaction in the non-perturbative regime. Both, in theory and in experiment, large progress has been made during the last few years. The rapid developments in lattice gauge calculations and the application of the Dyson-Schwinger equation to QCD have opened new perspectives for the interpretation of the excitation spectrum of the nucleon. In parallel, large efforts have been undertaken world-wide, and are still running, to investigate excited nucleon states experimentally, in particular with photon-induced production of mesons. In the present contribution we discuss such experimental programs conducted at the tagged photon beams of the electron accelerators ELSA in Bonn and MAMI in Mainz. These programs are diverse. They include the measurement of cross sections, single- and double polarization observables for single meson production and production of meson pairs off free protons as well as of quasi-free nucleons bound in the deuteron (and sometimes other light nuclei.
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.
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.
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.
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.
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.
Development of PID counter for charmed baryon spectroscopy experiment at J-PARC
Energy Technology Data Exchange (ETDEWEB)
Yamaga, T. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1, Mihogaoka, Ibaraki-shi, Osaka 567-0047 (Japan); Ishikawa, T. [ELPH, Tohoku University, 1-2-1, Mikamine, Taihaku-ku, Sendai-shi, Miyagi (Japan); Miyachi, Y. [Department of Physics, Yamagata University, 1-4-12, Shirakawa-cho, Yamagata-shi, Yamagata 990-8560 (Japan); Morino, Y. [RIKEN Nishina Center, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Nakano, T.; Noumi, H. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1, Mihogaoka, Ibaraki-shi, Osaka 567-0047 (Japan); Ozawa, K. [KEK, 1-1, Oho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Shirotori, K.; Sugaya, Y. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1, Mihogaoka, Ibaraki-shi, Osaka 567-0047 (Japan); Tanida, K. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)
2014-12-01
We have proposed an experiment for studying charmed baryons via the p(π{sup −},D{sup ⁎−}) reaction at the J-PARC high-momentum beam line. Charmed baryons will be measured by a missing mass method. Scattered D{sup ⁎−} will be reconstructed by detecting its decay chain of D{sup ⁎−}→D{sup ¯0}π{sup −}→K{sup +}π{sup −}π{sup −}. We designed a Ring Imaging Cherenkov (RICH) counter with two radiators, aerogel and C{sub 4}F{sub 10} of refractive indices 1.04 and 1.00137, respectively, in order to identify pions and kaons in a wide momentum range from 2 to 16 GeV/c. Spherical mirrors will be used to focus Cherenkov photons to the photon sensor alloys. The performance of the designed RICH counter is evaluated by a Monte-Carlo simulation based on GEANT4. Detection efficiency for scattered particles averaged over π and K is found to be 99%. Wrong particle identification ratios of pions and protons to kaons are 0.1% and 0.14%, respectively. The background level in the inclusive p(π{sup −},D{sup ⁎−}) spectrum increases only 5% due to the wrong identifications. - Highlights: • We design the PID counter for using charmed baryon spectroscopy experiment at JPARC. • The designed PID counter was studied with GEANT4 simulation and expected particle distribution in the experiment. • The estimated efficiency of pion and kaon is about 99% and wrong ID ratio is small enough.
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.
Excited-state spectroscopy of singly, doubly and triply-charmed baryons from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Padmanath, M. [Tata Institute; Edwards, Robert G. [JLAB; Mathur, Nilmani [Tata Institute; Peardon, Michael [Trinity College
2014-07-01
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. These operators transform as irreducible representations of SU(3)F symmetry for flavour, SU(4) symmetry for Dirac spins of quarks and O(3) symmetry for orbital angular momenta. 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)ⓍO(3) symmetry.
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.
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.
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.
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.
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.
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...
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)
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)
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.
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...
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.
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.
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.
Energy Technology Data Exchange (ETDEWEB)
Wick, Felix [Karlsruhe Inst. of Technology (Germany)
2011-10-28
In this thesis two different analyses are presented, namely the measurements of the properties of $\\Lambda_c(2595)^+$, $\\Lambda_c(2625)^+$, $\\Sigma_c(2455)^{++,0}$, and $\\Sigma_c(2520)^{++,0}$ baryons as well as the search for $CP$ violation in the Dalitz plot of the decay $D^0 \\to K_S^0\\,\\pi^+\\,\\pi^-$. Both studies are performed using data corresponding to 5.2\\,\\invfb respective 6.0\\,\\invfb of integrated luminosity from $p\\bar{p}$ collisions at a center-of-mass energy of 1.96\\,TeV, collected with the CDF~II detector at the Fermilab Tevatron. The masses and decay widths of the mentioned charmed baryon resonances are measured with uncertainties comparable to the world averages for $\\Sigma_c$ states, and significantly smaller uncertainties than the world averages for excited $\\Lambda_c^+$ states. No hints for any $CP$ violating effects in the resonant substructure of $D^0 \\to K_S^0\\,\\pi^+\\,\\pi^-$ are found.
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.
(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.
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.
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. )
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 ...
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
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.
Baryon spectroscopy on the lattice: recent results
Morningstar, Colin
2003-01-01
Comment: 5 pages, 4 figures, talk presented at the Conference on the Intersections of Particle and Nuclear Physics, New York, NY, May 19-24, 2003, submitted to American Institute of Physics Conference Proceedings. After publication, it will be found at http://proceedings.aip.org/proceedings/
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.
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.
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...
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.)
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
Energy Technology Data Exchange (ETDEWEB)
Hellman, Hal
1968-01-01
This booklet discusses spectroscopy, the study of absorption of radiation by matter, including X-ray, gamma-ray, microwave, mass spectroscopy, as well as others. Spectroscopy has produced more fundamental information to the study of the detailed structure of matter than any other tools.
Walker, S
1976-01-01
The three volumes of Spectroscopy constitute the one comprehensive text available on the principles, practice and applications of spectroscopy. By giving full accounts of those spectroscopic techniques only recently introduced into student courses - such as Mössbauer spectroscopy and photoelectron spectroscopy - in addition to those techniques long recognised as being essential in chemistry teaching - sucha as e.s.r. and infrared spectroscopy - the book caters for the complete requirements of undergraduate students and at the same time provides a sound introduction to special topics for graduate students.
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 ...
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.
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+}.
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.
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...
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.
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.
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 +
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
DEFF Research Database (Denmark)
Berg, Rolf W.
This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules.......This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules....
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
Speculations in hadron spectroscopy
Richard, J M
2005-01-01
A selected survey is presented of the recent progress in hadron spectroscopy. This includes spin-singlet charmonium states, excitations of charmonium and open-charm mesons, double-charm baryons, and pentaquark candidates. Models proposing exotic bound states or resonances are reviewed. The sector of exotic mesons with two heavy quarks appears as particularly promising.
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.
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).
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.
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.
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.
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.
Baryon content and dynamic state of galaxy clusters
Wang, D.
2016-06-01
We are carrying out a panchromatic observing program to study the baryon content and dynamic state of galaxy clusters. In this talk, I will present results primarily from XMM-Newton observations of optically-selected clusters in the redshift range of 0.1-0.4. These clusters are selected because of their fortuitous alignment with background far-UV-bright QSOs, which thus allows for Ly-alpha and O VI absorption line spectroscopy with HST/COS, probing physical processes of the evolving intracluster medium, freshly accreted from the intergalactic medium and/or stripped out of individual galaxies, as well as the gaseous halos of individual cluster galaxies. Interestingly, such clusters tend to be dynamically young and often consist of merging subcluster pairs at similar redshifts. These subclusters themselves typically show substantial substructures, including strongly distorted radio lobes, as well as large position offsets between the diffuse X-ray centroids and the brightest galaxies. A comparison of the hot gas and stellar masses of each cluster with the expected cosmological baryonic mass fraction indicates a significant room for other gas components. I will also briefly examine the limitations of both optically and X-ray selected clusters, as well as how they may be used in a complementary fashion.
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...
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
Erickcek, Adrienne L; McCammon, Dan; McGuire, Patrick C
2007-01-01
Although the rocket-based X-ray Quantum Calorimetry (XQC) experiment was designed for X-ray spectroscopy, the minimal shielding of its calorimeters, its low atmospheric overburden, and its low-threshold detectors make it among the most sensitive instruments for detecting or constraining strong interactions between dark matter particles and baryons. We use Monte Carlo simulations to obtain the precise limits the XQC experiment places on spin-independent interactions between dark matter and baryons, improving upon earlier analytical estimates. We find that the XQC experiment rules out a wide range of nucleon-scattering cross sections centered around one barn for dark matter particles with masses between 0.01 and 10^5 GeV. Our analysis also provides new constraints on cases where only a fraction of the dark matter strongly interacts with baryons.
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.
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.
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.
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.
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.
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¯.
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 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
Markov-Yukawa Transversality On Covariant Null-Plane Baryon Form Factor And Magnetic Moments
Mitra, A N
2001-01-01
The baryon-$qqq$ vertex function governed by the Markov-Yukawa Transversality Principle ($MYTP$), is formulated via the Covariant Null-Plane Ansatz ($CNPA$) as a 3-body generalization of the corresponding $q{\\bar q}$ problem, and employed to calculate the proton e.m. form factor and baryon octet magnetic moments.The e.m. coupling scheme is specified by letting the e.m. field interact by turn with the `spectator' while the two interacting quarks fold back into the baryon. The $S_3$ symmetry of the matrix element is preserved in all d.o.f.'s together. The $CNPA$ formulation ensures, as in the $q{\\bar q}$ case, that the loop integral is free from the Lorentz mismatch disease of covariant instantaneity ($CIA$), while the simple trick of `Lorentz completion'ensures a Lorentz invariant structure. The $k^{-4}$ scaling behaviour at large $k^2$ is reproduced. And with the infrared structure of the gluonic propagator attuned to spectroscopy, the charge radius of the proton comes out at $0.96 fm$. The magnetic moments o...
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...
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...
The impact of baryons on massive galaxy clusters: halo structure and cluster mass estimates
Henson, Monique A.; Barnes, David J.; Kay, Scott T.; McCarthy, Ian G.; Schaye, Joop
2017-03-01
We use the BAHAMAS (BAryons and HAloes of MAssive Systems) and MACSIS (MAssive ClusterS and Intercluster Structures) hydrodynamic simulations to quantify the impact of baryons on the mass distribution and dynamics of massive galaxy clusters, as well as the bias in X-ray and weak lensing mass estimates. These simulations use the subgrid physics models calibrated in the BAHAMAS project, which include feedback from both supernovae and active galactic nuclei. They form a cluster population covering almost two orders of magnitude in mass, with more than 3500 clusters with masses greater than 1014 M⊙ at z = 0. We start by characterizing the clusters in terms of their spin, shape and density profile, before considering the bias in both weak lensing and hydrostatic mass estimates. Whilst including baryonic effects leads to more spherical, centrally concentrated clusters, the median weak lensing mass bias is unaffected by the presence of baryons. In both the dark matter only and hydrodynamic simulations, the weak lensing measurements underestimate cluster masses by ≈10 per cent for clusters with M200 ≤ 1015 M⊙ and this bias tends to zero at higher masses. We also consider the hydrostatic bias when using both the true density and temperature profiles, and those derived from X-ray spectroscopy. When using spectroscopic temperatures and densities, the hydrostatic bias decreases as a function of mass, leading to a bias of ≈40 per cent for clusters with M500 ≥ 1015 M⊙. This is due to the presence of cooler gas in the cluster outskirts. Using mass weighted temperatures and the true density profile reduces this bias to 5-15 per cent.
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.
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.
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.
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 ...
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.
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.
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.
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.
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 $\\Lambda_b^{*0}(5920)$.
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.
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.
Spectroscopy and Decay of B Hadrons at the Tevatron
Paulini, M
2007-01-01
This paper reviews the spectroscopy and decay of B hadrons at the Tevatron. We discuss the spectroscopy of excited B states (B**, Bs**) and the observation of the Sigma_b baryon at the Tevatron. The second part of this review discusses the decays of B hadrons and measurements of branching fractions. We focus on charmless two-body decays of B->hh.
Overview of LHCb results on beauty and charm spectroscopy
Palano, Antimo
2016-11-01
We present a summary of new experimental results from LHCb experiment on the status of the charm spectroscopy using inclusive approaches and Dalitz plot analyses of B and Bs decays. We also summarize latest results on the spectroscopy of heavy baryons.
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.
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...
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)
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.
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.
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.
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.
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¯.
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.
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...
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...
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.
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.
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...
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.
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.
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.
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.
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.
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 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...
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 $\
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.
Prakash, Abhishek; SDSS-IV/eBOSS
2017-01-01
SDSS-IV/eBOSS survey will allow a ˜1% measurement of the Baryon Acoustic Oscillation (BAO) scale and a 4.0%Redshift Space Distortion (RSD) measurement using a relatively uniform set of luminous, early-type galaxies in the redshift range 0.6 image both wider areas and deeper volumes than would be possible with spectroscopy, allowing one to probe both larger scales and larger volumes. The ability to make precise clustering measurements with photometric data has been well demonstrated by Padmanabhan et al. (2007).
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.)
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.
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
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; 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.
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.
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
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
CEBAF at higher energies: Working group report on hadron spectroscopy and production
Energy Technology Data Exchange (ETDEWEB)
Barnes, T. [Oak Ridge National Laboratory, TN (United States)]| [Univ. of Tennessee, Knoxville (United States); Napolitano, J. [Rensselaer Polytechnic Inst., Troy, NY (United States)
1994-04-01
This report summarizes topics in hadron spectroscopy and production which could be addressed at CEBAF with an energy upgrade to E{sub {gamma}} = 8 GeV and beyond. The topics discussed include conventional meson and baryon spectrocopy, spectroscopy of exotica (especially molecules and hybrids), CP and CPT tests using {phi} mesons, and new detector and accelerator options.
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...
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...
DIOS: the dark baryon exploring mission
Ohashi, T; Ezoe, Y; Yamada, S; Yamaguchi, S; Miyazaki, N; Tawara, Y; Mitsuda, K; Yamasaki, N Y; Takei, Y; Sakai, K; Nagayoshi, K; Yamamoto, R; Chiba, A; Hayashi, T
2015-01-01
DIOS (Diffuse Intergalactic Oxygen Surveyor) is a small satellite aiming for a launch around 2020 with JAXA's Epsilon rocket. Its main aim is a search for warm-hot intergalactic medium with high-resolution X-ray spectroscopy of redshifted emission lines from OVII and OVIII ions. The superior energy resolution of TES microcalorimeters combined with a very wide field of view (30--50 arcmin diameter) will enable us to look into gas dynamics of cosmic plasmas in a wide range of spatial scales from Earth's magnetosphere to unvirialized regions of clusters of galaxies. Mechanical and thermal design of the spacecraft and development of the TES calorimeter system are described. We also consider revising the payload design to optimize the scientific capability allowed by the boundary conditions of the small mission.
DIOS: the dark baryon exploring mission
Ohashi, T.; Ishisaki, Y.; Ezoe, Y.; Yamada, S.; Kuromaru, G.; Suzuki, S.; Tawara, Y.; Mitsuishi, I.; Babazaki, Y.; Mitsuda, K.; Yamasaki, N. Y.; Takei, Y.; Yamamoto, R.; Hayashi, T.; Ota, N.; Kelley, R. L.; Sakai, K.
2016-07-01
DIOS (Diffuse Intergalactic Oxygen Surveyor) is a small satellite aiming for a launch around 2022 with JAXA's Epsilon rocket. Its main aim is a search for warm-hot intergalactic medium with high-resolution X-ray spectroscopy of redshifted emission lines from OVII and OVIII ions. The superior energy resolution of TES microcalorimeters combined with a wide field of view (30' diameter) will enable us to look into gas dynamics of cosmic plasmas in a wide range of spatial scales from Earth's magnetosphere to unvirialized regions of clusters of galaxies. Mechanical and thermal design of the spacecraft and development of the TES calorimeter system are described. Employing an enlarged X-ray telescope with a focal length of 1.2 m and fast repointing capability, DIOS can observe absorption features from X-ray afterglows of distant gamma-ray bursts.
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.
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 $(I)J^P=(2)3/2^-$.
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.
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.
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.
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...
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; 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; 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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.
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.
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.
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.
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.
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.
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)
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.
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.
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 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...
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...
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...
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.
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.
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.
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.
Raichoor, A; Delubac, T; Kneib, J -P; Yèche, C; Zou, H; Abdalla, F B; Dawson, K; Fan, X; Fan, Z; Jiang, Z; Jing, Y; Jouvel, S; Lang, D; Lesser, M; Li, C; Ma, J; Newman, J A; Nie, J; Olszewski, E; Palanque-Delabrouille, N; Percival, W; Prada, F; Shen, S; Wang, J; Wu, Z; Zhang, T; Zhou, X; Zhou, Z
2015-01-01
We present a new selection technique to produce spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which will use 200,000 emission line galaxies (ELGs) at 0.6
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.)
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.
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
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.
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; 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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; 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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
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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.
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{\
Sigma Terms and Strangeness Contents of Baryon Octet in Modified Chiral Perturbation Theory
Institute of Scientific and Technical Information of China (English)
LI Xiao-Ya; L(U) Xiao-Fu
2006-01-01
In the frame work of chiral perturbation theory, a modified effective Lagrangian for meson-baryon system is constructed, where the SU(3) breaking effect for meson is considered. The difference between physical and chiral limit decay constants is taken into account. Calculated to one loop at O(p3), the sigma terms and strangeness contents of baryon octet are obtained.
Spinodal amplification and baryon number fluctuations in nuclear collisions at NICA
Energy Technology Data Exchange (ETDEWEB)
Steinheimer, Jan [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Randrup, Joergen [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, California (United States)
2016-08-15
We discuss the effect of spinodal instabilities on the fluctuations of conserved flavors in nuclear collisions at NICA. We find that, when the system undergoes a phase transformation, baryon number clumping due to the mechanical instabilities in the spinodal phase occurs. This dynamical clumping enhances the cumulants of the net baryon number residing in a finite test volume of the total collision system. (orig.)
Baryons in the large N limit of the massive NJL2 model
Boehmer, Christian; Thies, Michael
2008-01-01
Baryons in the massive Nambu-Jona-Lasinio model in 1+1 dimensions (the massive chiral Gross-Neveu model) are studied in the limit of an infinite number of flavors. The baryon mass is evaluated for a wide range of bare fermion masses and filling fractions, combining analytical asymptotic expansions with a full numerical Hartree-Fock calculation.
The Spin Symmetry of Heavy Baryons in the Framework of the Bethe-Salpeter Equation
Institute of Scientific and Technical Information of China (English)
CUI Jian-Ying; JIN Hong-Ying; WU Ji-Min
2001-01-01
We study the baryons containing a heavy quark in the framework of Bethe-Salpeter (BS) equation. The most general forms of the BS wavefunctions are given. In the heavy-quark limit we simplify the BS equations and we show clearly that the spin symmetry exists in heavy baryon states.``
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.
Liang, Wei-Hong; Xiao, C. W.; Oset, E.
2016-05-01
In this talk we review the results about the interaction of B ¯N , B ¯Δ, B ¯*N and B ¯*Δ states with beauty B = 1, together with their coupled channels, using the extended local hidden gauge approach. The Λb(5912) and Λb(5920) observed in the experiment are dynamically generated from the meson-baryon interaction, and they couple mostly to B ¯*N , which are degenerate with the Weinberg-Tomozawa interaction. In addition, three more states with I = 0 and eight more states with I = 1 are predicted.
Energy Technology Data Exchange (ETDEWEB)
Sanctis, M. de [Universidad Nacional de Colombia, Bogota (Colombia); Ferretti, J. [Universita La Sapienza, Dipartimento di Fisica, Roma (Italy); INFN, Roma (Italy); Santopinto, E.; Vassallo, A. [INFN, Sezione di Genova, Genova (Italy)
2016-05-15
The relativistic interacting quark-diquark model of baryons, recently developed, is here extended introducing in the mass operator a spin-isospin transition interaction. This refined version of the model is used to calculate the non-strange baryon spectrum. The results are compared to the present experimental data. A preliminary calculation of the magnetic moments of the proton and neutron is also presented. (orig.)
Light baryon masses with dynamical twisted mass fermions
Alexandrou, C; Blossier, B; Brinet, M; Carbonell, J; Dimopoulos, P; Drach, V; Farchioni, F; Frezzotti, R; Guichon, P; Herdoiza, G; Jansen, K; Korzec, T; Koutsou, G; Liu, Z; Michael, C; Pène, O; Shindler, A; Urbach, C; Wenger, U
2008-01-01
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 about 300-600 MeV on lattices of 2.1-2.7 fm. We check for cut-off effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at beta=3.9 and beta=4.05 and on a lattice of 2.4 fm at beta=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at beta=3.9 and beta=4.05 we find a nucleon mass of 964\\pm 28 (stat.) \\pm 8 (syst.) MeV. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p^3) we find a_{\\beta=3.9}=0.0890\\pm 0.0039(stat.) \\pm 0.0014(syst.) fm, and a_{\\beta=4.05}= 0.0691\\pm 0.0034(stat.) \\pm 0.0010(syst.) fm, in good agreement w...
Baryon Census in Hydrodynamical Simulations of Galaxy Clusters
Planelles, Susana; Dolag, Klaus; Ettori, Stefano; Fabjan, Dunja; Murante, Giuseppe; Tornatore, Luca
2012-01-01
We carry out an analysis of a set of cosmological SPH hydrodynamical simulations of galaxy clusters and groups aimed at studying the total baryon budget in clusters, and how this budget is shared between the hot diffuse component and the stellar component. Using the TreePM+SPH GADGET-3 code, we carried out one set of non-radiative simulations, and two sets of simulations including radiative cooling, star formation and feedback from supernovae (SN), one of which also accounting for the effect of feedback from active galactic nuclei (AGN). The analysis is carried out with the twofold aim of studying the implication of stellar and hot gas content on the relative role played by SN and AGN feedback, and to calibrate the cluster baryon fraction and its evolution as a cosmological tool. We find that both radiative simulation sets predict a trend of stellar mass fraction with cluster mass that tends to be weaker than the observed one. However this tension depends on the particular set of observational data considered...
Chiral perturbation theory analysis of baryon temperature mass shifts
Bedaque, P F
1995-01-01
We compute the finite temperature pole mass shifts of the octet and decuplet baryons using heavy baryon chiral perturbation theory and the 1/N_c expansion, where N_c is the number of QCD colors. We consider the temperatures of the order of the pion mass m_\\pi, and expand truncate the chiral and 1/N_c expansions assuming that m_\\pi \\sim 1/N_c. There are three scales in the problem: the temperature T, the pion mass m_\\pi, and the octet--decuplet mass difference. Therefore, the result is not simply a power series in T. We find that the nucleon and \\Delta temperature mass shifts are opposite in sign, and that their mass difference changes by 20% in the temperature range 90 MeV < T < 130 MeV, that is the range where the freeze out in relativistic heavy ion collisions is expected to occur. We argue that our results are insensitive to the neglect of 1/N_c- supressed effects; the main purpose of the 1/N_c expansion in this work is to justify our treatment of the decuplet states.
Baryon-Size Dependent Location of QCD Critical Point
Srivastava, P K; Singh, C P
2011-01-01
The physics regarding the existence of the critical end point (CEP) on the QCD phase boundary still remains unclear and its precise location is quite uncertain. In this paper we propose that the hard-core size of the baryons used in the description of the hot and dense hadron gas (HG) plays a decisive role in the existence of CEP. Here we construct a deconfining phase transition using Gibbs' equilibrium conditions after using a quasiparticle equation of state (EOS) for QCD plasma and excluded-volume EOS for the HG. We find that the first order transition results only when we assign a hard-core size to each baryon in the description of HG and the phase boundary thus obtained terminates at CEP beyond which a cross-over region occurs. The mean field approach for the HG lends support to this finding where unless we include an excluded-volume effect in the approach, CEP does not materialize on the QCD boundary. This investigation provides an intuitive reasoning regarding the origin of CEP and the cross-over transi...
Generating the Observed Baryon Asymmetry from the Inflaton Field
Hertzberg, Mark P
2013-01-01
We propose a mechanism by which the inflaton can generate baryogenesis, by taking the inflaton to be a complex scalar field with a weakly broken global symmetry and present a new version of the Affleck-Dine mechanism. The smallness of the breaking is motivated both by technical naturalness and a requirement for inflation. We study inflation driven by a quadratic potential for simplicity and discuss generalizations to other potentials. We compute the inflationary dynamics and find that a conserved particle number is obtained towards the end of inflation. We then explain in detail the later decay to baryons. We present two promising embeddings in particle physics: (i) using high dimension operators for a gauge singlet; we find this leads to the observed asymmetry for decay controlled by the ~GUT scale and this is precisely the regime where the EFT applies. (ii) using a colored inflaton, which requires small couplings. We also point out two observational consequences: a possible large scale dipole in the baryon ...
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...
Forming supermassive black holes by accreting dark and baryon matter
Hu, J; Lou, Y Q; Zhang, S; Hu, Jian; Shen, Yue; Lou, Yu-Qing; Zhang, Shuangnan
2006-01-01
Given a large-scale mixture of self-interacting dark matter (SIDM) particles and baryon matter distributed in the early Universe, we advance here a two-phase accretion scenario for forming supermassive black holes (SMBHs) with masses around $\\sim 10^9 M_{\\odot}$ at high redshifts $z (\\gsim 6)$. The first phase is conceived to involve a rapid quasi-spherical and quasi-steady Bondi accretion of mainly SIDM particles embedded with baryon matter onto seed black holes (BHs) created at redshifts $z\\lsim 30$ by the first generation of massive Population III stars; this earlier phase rapidly gives birth to significantly enlarged seed BH masses of $M_{\\hbox{\\tiny BH},t_1}\\backsimeq 1.4\\times 10^6\\ M_\\odot \\sigma_0/(1\\hbox{cm}^2\\hbox{g}^{-1})(C_s/30\\hbox{km s}^{-1})^4$ during $z\\sim 20-15$, where $\\sigma_0$ is the cross section per unit mass of SIDM particles and $C_s$ is the velocity dispersion in the SIDM halo referred to as an effective "sound speed". The second phase of BH mass growth is envisaged to proceed primar...
Probing the spin-parity of the pentaquark $\\Theta^+$ baryon
Barmin, V V; Curceanu, C; Davidenko, G V; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tarasov, V V
2015-01-01
Using the DIANA data on the charge-exchange reaction K^+n --> pK^0 on a bound neutron, in which the s-channel formation of the pentaquark baryon \\Theta^+(1538) has been observed,we analyze the dependence of the background-subtracted \\Theta^+ --> pK^0 signal on the K^0 emission angle in the pK^0 rest frame. The data are consistent with the angular dependence of a form dW/d\\cos\\Theta_cms ~ (\\cos\\Theta_cms + A)^2 with a positive offset A. This form of the \\cos\\Theta_cms distribution suggests an interference between the \\Theta-mediated p-wave contribution and the nonresonant s-wave contribution to the total amplitude of the charge-exchange reaction. The p-wave nature of the \\Theta-mediated amplitude is consistent with the spin-parity assignment of 1/2^+ for the \\Theta^+ baryon. The selection in \\cos\\Theta_cms based on the observed angular dependence of the \\Theta^+ --> pK^0 signal allows to boost the statistical significance of the signal up to 6.8 standard deviations. \\e
Tying dark matter to baryons with self-interactions.
Kaplinghat, Manoj; Keeley, Ryan E; Linden, Tim; Yu, Hai-Bo
2014-07-11
Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter paradigm. We derive equilibrium solutions in these SIDM models for the dark matter halo density profile including the gravitational potential of both baryons and dark matter. Self-interactions drive dark matter to be isothermal and this ties the core sizes and shapes of dark matter halos to the spatial distribution of the stars, a radical departure from previous expectations and from cold dark matter predictions. Compared to predictions of SIDM-only simulations, the core sizes are smaller and the core densities are higher, with the largest effects in baryon-dominated galaxies. As an example, we find a core size around 0.3 kpc for dark matter in the Milky Way, more than an order of magnitude smaller than the core size from SIDM-only simulations, which has important implications for indirect searches of SIDM candidates.
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...
Observation of a new Ξb baryon.
Chatrchyan, S; Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Bergauer, T; Dragicevic, M; Erö, J; Fabjan, C; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hörmann, N; Hrubec, J; Jeitler, M; Kiesenhofer, W; Knünz, V; Krammer, M; Liko, D; Mikulec, I; Pernicka, M; Rahbaran, B; Rohringer, C; Rohringer, H; Schöfbeck, R; Strauss, J; Taurok, A; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C-E; Mossolov, V; Shumeiko, N; Suarez Gonzalez, J; Bansal, S; Cornelis, T; De Wolf, E A; Janssen, X; Luyckx, S; Maes, T; Mucibello, L; Ochesanu, S; Roland, B; Rougny, R; Selvaggi, M; Staykova, Z; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Van Spilbeeck, A; Blekman, F; Blyweert, S; D'Hondt, J; Gonzalez Suarez, R; Kalogeropoulos, A; Maes, M; Olbrechts, A; Van Doninck, W; Van Mulders, P; Van Onsem, G P; Villella, I; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Gay, A P R; Hreus, T; Léonard, A; Marage, P E; Reis, T; Thomas, L; Vander Velde, C; Vanlaer, P; Wang, J; Adler, V; Beernaert, K; Cimmino, A; Costantini, S; Garcia, G; Grunewald, M; Klein, B; Lellouch, J; Marinov, A; McCartin, J; Ocampo Rios, A A; Ryckbosch, D; Strobbe, N; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Walsh, S; Yazgan, E; Zaganidis, N; Basegmez, S; Bruno, G; Castello, R; Ceard, L; Delaere, C; du Pree, T; Favart, D; Forthomme, L; Giammanco, A; Hollar, J; Lemaitre, V; Liao, J; Militaru, O; Nuttens, C; Pagano, D; Pin, A; Piotrzkowski, K; Schul, N; Vizan Garcia, J M; Beliy, N; Caebergs, T; Daubie, E; Hammad, G H; Alves, G A; Correa Martins Junior, M; De Jesus Damiao, D; Martins, T; Pol, M E; Souza, M H G; Aldá Júnior, W L; Carvalho, W; Custódio, A; Da Costa, E M; De Oliveira Martins, C; Fonseca De Souza, S; Matos Figueiredo, D; Mundim, L; Nogima, H; Oguri, V; Prado Da Silva, W L; Santoro, A; Soares Jorge, L; Sznajder, A; Bernardes, C A; Dias, F A; Fernandez Perez Tomei, T R; Gregores, E M; Lagana, C; Marinho, F; Mercadante, P G; Novaes, S F; Padula, Sandra S; Genchev, V; Iaydjiev, P; Piperov, S; Rodozov, M; Stoykova, S; Sultanov, G; Tcholakov, V; Trayanov, R; Vutova, M; Dimitrov, A; Hadjiiska, R; Kozhuharov, V; Litov, L; Pavlov, B; Petkov, P; Bian, J G; Chen, G M; Chen, H S; Jiang, C H; Liang, D; Liang, S; Meng, X; Tao, J; Wang, J; Wang, X; Wang, Z; Xiao, H; Xu, M; Zang, J; Zhang, Z; Asawatangtrakuldee, C; Ban, Y; Guo, S; Guo, Y; Li, W; Liu, S; Mao, Y; Qian, S J; Teng, H; Wang, S; Zhu, B; Zou, W; Avila, C; Gomez, J P; Gomez Moreno, B; Osorio Oliveros, A F; Sanabria, J C; Godinovic, N; Lelas, D; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Kovac, M; Brigljevic, V; Duric, S; Kadija, K; Luetic, J; Morovic, S; Attikis, A; Galanti, M; Mavromanolakis, G; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Finger, M; Finger, M; Assran, Y; Elgammal, S; Ellithi Kamel, A; Khalil, S; Mahmoud, M A; Radi, A; Kadastik, M; Müntel, M; Raidal, M; Rebane, L; Tiko, A; Azzolini, V; Eerola, P; Fedi, G; Voutilainen, M; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Peltola, T; Tuominen, E; Tuominiemi, J; Tuovinen, E; Ungaro, D; Wendland, L; Banzuzi, K; Karjalainen, A; Korpela, A; Tuuva, T; Besancon, M; Choudhury, S; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Locci, E; Malcles, J; Millischer, L; Nayak, A; Rander, J; Rosowsky, A; Shreyber, I; Titov, M; Baffioni, S; Beaudette, F; Benhabib, L; Bianchini, L; Bluj, M; Broutin, C; Busson, P; Charlot, C; Daci, N; Dahms, T; Dobrzynski, L; Granier de Cassagnac, R; Haguenauer, M; Miné, P; Mironov, C; Nguyen, M; Ochando, C; Paganini, P; Sabes, D; Salerno, R; Sirois, Y; Veelken, C; Zabi, A; Agram, J-L; Andrea, J; Bloch, D; Bodin, D; Brom, J-M; Cardaci, M; Chabert, E C; Collard, C; Conte, E; Drouhin, F; Ferro, C; Fontaine, J-C; Gelé, D; Goerlach, U; Juillot, P; Le Bihan, A-C; Van Hove, P; Fassi, F; Mercier, D; Beauceron, S; Beaupere, N; Bondu, O; Boudoul, G; Brun, H; Chasserat, J; Chierici, R; Contardo, D; Depasse, P; El Mamouni, H; Fay, J; Gascon, S; Gouzevitch, M; Ille, B; Kurca, T; Lethuillier, M; Mirabito, L; Perries, S; Sordini, V; Tosi, S; Tschudi, Y; Verdier, P; Viret, S; Tsamalaidze, Z; Anagnostou, G; Beranek, S; Edelhoff, M; Feld, L; Heracleous, N; Hindrichs, O; Jussen, R; Klein, K; Merz, J; Ostapchuk, A; Perieanu, A; Raupach, F; Sammet, J; Schael, S; Sprenger, D; Weber, H; Wittmer, B; Zhukov, V; Ata, M; Caudron, J; Dietz-Laursonn, E; Erdmann, M; Güth, A; Hebbeker, T; Heidemann, C; Hoepfner, K; Klingebiel, D; Kreuzer, P; Lingemann, J; Magass, C; Merschmeyer, M; Meyer, A; Olschewski, M; Papacz, P; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Steggemann, J; Teyssier, D; Weber, M; Bontenackels, M; Cherepanov, V; Flügge, G; Geenen, H; Geisler, M; Haj Ahmad, W
2012-06-22
The observation of a new b baryon via its strong decay into Ξ(b)(-) π(+) (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at sqrt[s] = 7 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 fb(-1). The known Ξ(b)(-) baryon is reconstructed via the decay chain Ξ(b)(-) → J/ψΞ(-) → μ(+) μ(-) Λ(0) π(-), with Λ(0) → pπ(-). A peak is observed in the distribution of the difference between the mass of the Ξ(b)(-) π(+) system and the sum of the masses of the Ξ(b)(-) and π(+), with a significance exceeding 5 standard deviations. The mass difference of the peak is 14.84 ± 0.74(stat) ± 0.28(syst) MeV. The new state most likely corresponds to the J(P) = 3/2(+) companion of the Ξ(b).
Dense baryonic matter: constraints from recent neutron star observations
Hell, Thomas
2014-01-01
Updated constraints from neutron star masses and radii impose stronger restrictions on the equation of state for baryonic matter at high densities and low temperatures. The existence of two-solar-mass neutron stars rules out many soft equations of state with prominent "exotic" compositions. The present work reviews the conditions required for the pressure as a function of baryon density in order to satisfy these new constraints. Several scenarios for sufficiently stiff equations of state are evaluated. The common starting point is a realistic description of both nuclear and neutron matter based on a chiral effective field theory approach to the nuclear many-body problem. Possible forms of hybrid matter featuring a quark core in the center of the star are discussed using a three-flavor Polyakov--Nambu--Jona-Lasinio (PNJL) model. It is found that a conventional equation of state based on nuclear chiral dynamics meets the astrophysical constraints. Hybrid matter generally turns out to be too soft unless addition...
Dark and baryonic matter in the MareNostrum Universe
Gottlöber, S.; Yepes, G.; Khalatyan, A.; Sevilla, R.; Turchaninov, V.
2006-11-01
We report some results from one of the largest hydrodynamical cosmological simulations of large scale structures that has been done up to date. The MareNostrum Universe SPH simulation consists of 2 billion particles (2 × 10243) in a cubic box of 500 h-1 Mpc on a side. This simulation has been done in the MareNostrum parallel supercomputer at the Barcelona SuperComputer Center. Due to the large simulated volume and good mass resolution, our simulated catalog of dark matter halos comprises more than half a million objects with masses larger than a typical Milky Way galaxy halo. From this dataset we have studied several statistical properties such as the halo mass function, the distribution of shapes of dark and gas components within halos, the baryon fraction, cumulative void volume etc. This simulation is particularly useful to study the large scale distribution of baryons in the universe as a function of temperature and density. In this paper we also show the time evolution of the gas fractions at large scales.
Observation of a New $\\Xi_{b}$ Baryon
Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rahbaran, Babak; Rohringer, Christine; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Wagner, Philipp; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Luyckx, Sten; Maes, Thomas; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Staykova, Zlatka; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Michael; Olbrechts, Annik; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Charaf, Otman; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hreus, Tomas; Léonard, Alexandre; Marage, Pierre Edouard; Reis, Thomas; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Cimmino, Anna; Costantini, Silvia; Garcia, Guillaume; Grunewald, Martin; Klein, Benjamin; Lellouch, Jérémie; Marinov, Andrey; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Vanelderen, Lukas; Verwilligen, Piet; Walsh, Sinead; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Castello, Roberto; Ceard, Ludivine; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Alves, Gilvan; Correa Martins Junior, Marcos; De Jesus Damiao, Dilson; Martins, Thiago; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Custódio, Analu; Da Costa, Eliza Melo; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Soares Jorge, Luana; Sznajder, Andre; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Lagana, Caio; Da Cunha Marinho, Franciole; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vutova, Mariana; Dimitrov, Anton; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xiao, Hong; Xu, Ming; Zang, Jingjing; Zhang, Zhen; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Shuang; Guo, Yifei; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Wang, Siguang; Zhu, Bo; Zou, Wei; Avila, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Luetic, Jelena; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Ellithi Kamel, Ali; Khalil, Shaaban; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Müntel, Mait; Raidal, Martti; Rebane, Liis; Tiko, Andres; Azzolini, Virginia; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Karjalainen, Ahti; Korpela, Arja; Tuuva, Tuure; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Millischer, Laurent; Nayak, Aruna; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Benhabib, Lamia; Bianchini, Lorenzo; Bluj, Michal; Broutin, Clementine; Busson, Philippe; Charlot, Claude; Daci, Nadir; Dahms, Torsten; Dobrzynski, Ludwik; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Nguyen, Matthew; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sirois, Yves; Veelken, Christian; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Ferro, Cristina; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Juillot, Pierre; Le Bihan, Anne-Catherine; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Beauceron, Stephanie; Beaupere, Nicolas; Bondu, Olivier; Boudoul, Gaelle; Brun, Hugues; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sordini, Viola; Tosi, Silvano; Tschudi, Yohann; Verdier, Patrice; Viret, Sébastien; Tsamalaidze, Zviad; Anagnostou, Georgios; Beranek, Sarah; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Caudron, Julien; Dietz-Laursonn, Erik; Erdmann, Martin; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Kreuzer, Peter; Lingemann, Joschka; Magass, Carsten; Merschmeyer, Markus; Meyer, Arnd; Olschewski, Mark; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Weber, Martin; Bontenackels, Michael; Cherepanov, Vladimir; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Rennefeld, Jörg; Sauerland, Philip; Stahl, Achim; Aldaya Martin, Maria; Behr, Joerg; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Castro, Elena; Costanza, Francesco; Dammann, Dirk; Eckerlin, Guenter; Eckstein, Doris; Fischer, David; Flucke, Gero; Geiser, Achim; Glushkov, Ivan; Habib, Shiraz; Hauk, Johannes; Jung, Hannes; Kasemann, Matthias; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krämer, Mira; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Olzem, Jan; Perrey, Hanno; Petrukhin, Alexey; Pitzl, Daniel; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Riedl, Caroline; Rosin, Michele; Salfeld-Nebgen, Jakob; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Spiridonov, Alexander; Stein, Matthias; Walsh, Roberval; Wissing, Christoph; Autermann, Christian; Blobel, Volker; Bobrovskyi, Sergei; Draeger, Jula; Enderle, Holger; Erfle, Joachim; Gebbert, Ulla; Görner, Martin; Hermanns, Thomas; Höing, Rebekka Sophie; Kaschube, Kolja; Kaussen, Gordon; Kirschenmann, Henning; Klanner, Robert; Lange, Jörn; Mura, Benedikt; Nowak, Friederike; Peiffer, Thomas; Pietsch, Niklas; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schröder, Matthias; Schum, Torben; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Barth, Christian; Berger, Joram; Chwalek, Thorsten; De Boer, Wim; Dierlamm, Alexander; Feindt, Michael; Guthoff, Moritz; Hackstein, Christoph; Hartmann, Frank; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Honc, Simon; Katkov, Igor; Komaragiri, Jyothsna Rani; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Nürnberg, Andreas; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Ratnikova, Natalia; Röcker, Steffen; Scheurer, Armin; Schilling, Frank-Peter; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Weiler, Thomas; Zeise, Manuel; Daskalakis, Georgios; Geralis, Theodoros; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Mavrommatis, Charalampos; Ntomari, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Saoulidou, Niki; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Radics, Balint; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Beni, Noemi; Czellar, Sandor; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Karancsi, János; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Jindal, Monika; Kaur, Manjit; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Jasbir; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Kumar, Ashok; Kumar, Arun; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Shivpuri, Ram Krishen; Banerjee, Sunanda; Bhattacharya, Satyaki; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Choudhury, Rajani Kant; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mehta, Pourus; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Aziz, Tariq; Ganguly, Sanmay; Guchait, Monoranjan; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Jafari, Abideh; Khakzad, Mohsen; Mohammadi, Abdollah; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Lusito, Letizia; Maggi, Giorgio; Maggi, Marcello; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pompili, Alexis; Pugliese, Gabriella; Selvaggi, Giovanna; Silvestris, Lucia; Singh, Gurpreet; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gianni; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Gonzi, Sandro; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cavallo, Nicola; De Cosa, Annapaola; Dogangun, Oktay; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bellan, Paolo; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dorigo, Tommaso; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Meneguzzo, Anna Teresa; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Zotto, Pierluigi; Zumerle, Gianni; Gabusi, Michele; Ratti, Sergio P; Riccardi, Cristina; Torre, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Fanò, Livio; Lariccia, Paolo; Lucaroni, Andrea; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Romeo, Francesco; Saha, Anirban; Santocchia, Attilio; Taroni, Silvia; Azzurri, Paolo; Bagliesi, Giuseppe; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Diemoz, Marcella; Grassi, Marco; Longo, Egidio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Sigamani, Michael; Soffi, Livia; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Botta, Cristina; Cartiglia, Nicolo; Costa, Marco; Demaria, Natale; Graziano, Alberto; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Vilela Pereira, Antonio; Belforte, Stefano; Candelise, Vieri; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Marone, Matteo; Montanino, Damiana; Penzo, Aldo; Schizzi, Andrea; Heo, Seong Gu; Kim, Tae Yeon; Nam, Soon-Kwon; Chang, Sunghyun; Chung, Jin Hyuk; Kim, Dong Hee; Kim, Gui Nyun; Kong, Dae Jung; Park, Hyangkyu; Ro, Sang-Ryul; Son, Dong-Chul; Son, Taejin; Kim, Jae Yool; Kim, Zero Jaeho; Song, Sanghyeon; Jo, Hyun Yong; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Choi, Minkyoo; Kang, Seokon; Kim, Ji Hyun; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Cho, Yongjin; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Min Suk; Kwon, Eunhyang; Lee, Byounghoon; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Juodagalvis, Andrius; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Magaña Villalba, Ricardo; Martínez-Ortega, Jorge; Sánchez-Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A; Krofcheck, David; Bell, Alan James; Butler, Philip H; Doesburg, Robert; Reucroft, Steve; Silverwood, Hamish; Ahmad, Muhammad; Asghar, Muhammad Irfan; Hoorani, Hafeez R; Khalid, Shoaib; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Shah, Mehar Ali; Shoaib, Muhammad; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Bialkowska, Helena; Boimska, Bozena; Frueboes, Tomasz; Gokieli, Ryszard; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Seixas, Joao; Varela, Joao; Vischia, Pietro; Belotelov, Ivan; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Malakhov, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Evstyukhin, Sergey; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Erofeeva, Maria; Gavrilov, Vladimir; Kossov, Mikhail; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Markina, Anastasia; Obraztsov, Stepan; Perfilov, Maxim; Petrushanko, Sergey; Popov, Andrey; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Korablev, Andrey; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Ekmedzic, Marko; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Diez Pardos, Carmen; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Soares, Mara Senghi; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Piedra Gomez, Jonatan; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Jorda, Clara; Lobelle Pardo, Patricia; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Sobron Sanudo, Mar; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Baillon, Paul; Ball, Austin; Barney, David; Bernet, Colin; Bianchi, Giovanni; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Christiansen, Tim; Coarasa Perez, Jose Antonio; D'Enterria, David; Dabrowski, Anne; De Roeck, Albert; Di Guida, Salvatore; Dobson, Marc; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Georgiou, Georgios; Giffels, Manuel; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Giunta, Marina; Glege, Frank; Gomez-Reino Garrido, Robert; Govoni, Pietro; Gowdy, Stephen; Guida, Roberto; Hansen, Magnus; Harris, Philip; Hartl, Christian; Harvey, John; Hegner, Benedikt; Hinzmann, Andreas; Innocente, Vincenzo; Janot, Patrick; Kaadze, Ketino; Karavakis, Edward; Kousouris, Konstantinos; Lecoq, Paul; Lee, Yen-Jie; Lenzi, Piergiulio; Lourenco, Carlos; Maki, Tuula; Malberti, Martina; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Musella, Pasquale; Nesvold, Erik; Orimoto, Toyoko; Orsini, Luciano; Palencia Cortezon, Enrique; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Polese, Giovanni; Quertenmont, Loic; Racz, Attila; Reece, William; Rodrigues Antunes, Joao; Rolandi, Gigi; Rommerskirchen, Tanja; Rovelli, Chiara; Rovere, Marco; Sakulin, Hannes; Santanastasio, Francesco; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sekmen, Sezen; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Spiropulu, Maria; Stoye, Markus; Tsirou, Andromachi; Veres, Gabor Istvan; Vlimant, Jean-Roch; Wöhri, Hermine Katharina; Worm, Steven; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Sibille, Jennifer; Bäni, Lukas; Bortignon, Pierluigi; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Deisher, Amanda; Dissertori, Günther; Dittmar, Michael; Dünser, Marc; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Hits, Dmitry; Lecomte, Pierre; Lustermann, Werner; Martinez Ruiz del Arbol, Pablo; Mohr, Niklas; Moortgat, Filip; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pape, Luc; Pauss, Felicitas; Peruzzi, Marco; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Starodumov, Andrei; Stieger, Benjamin; Takahashi, Maiko; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Hannsjoerg Artur; Wehrli, Lukas; Aguilo, Ernest; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; Favaro, Carlotta; Ivova Rikova, Mirena; Millan Mejias, Barbara; Otiougova, Polina; Robmann, Peter; Snoek, Hella; Tupputi, Salvatore; Verzetti, Mauro; Chang, Yuan-Hann; Chen, Kuan-Hsin; Kuo, Chia-Ming; Li, Syue-Wei; Lin, Willis; Liu, Zong-Kai; Lu, Yun-Ju; Mekterovic, Darko; Singh, Anil; Volpe, Roberta; Yu, Shin-Shan; Bartalini, Paolo; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Dietz, Charles; Grundler, Ulysses; Hou, George Wei-Shu; Hsiung, Yee; Kao, Kai-Yi; Lei, Yeong-Jyi; Lu, Rong-Shyang; Majumder, Devdatta; Petrakou, Eleni; Shi, Xin; Shiu, Jing-Ge; Tzeng, Yeng-Ming; Wan, Xia; Wang, Minzu; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Karapinar, Guler; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Latife Nukhet; Vergili, Mehmet; Akin, Ilina Vasileva; Aliev, Takhmasib; Bilin, Bugra; Bilmis, Selcuk; Deniz, Muhammed; Gamsizkan, Halil; Guler, Ali Murat; Ocalan, Kadir; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Surat, Ugur Emrah; Yalvac, Metin; Yildirim, Eda; Zeyrek, Mehmet; Gülmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Ozkorucuklu, Suat; Sonmez, Nasuf; Cankocak, Kerem; Levchuk, Leonid; Bostock, Francis; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Kreczko, Lukasz; Metson, Simon; Newbold, Dave M; Nirunpong, Kachanon; Poll, Anthony; Senkin, Sergey; Smith, Vincent J; Williams, Thomas; Basso, Lorenzo; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Jackson, James; Kennedy, Bruce W; Olaiya, Emmanuel; Petyt, David; Radburn-Smith, Benjamin Charles; Shepherd-Themistocleous, Claire; Tomalin, Ian R; Womersley, William John; Bainbridge, Robert; Ball, Gordon; Beuselinck, Raymond; Buchmuller, Oliver; Colling, David; Cripps, Nicholas; Cutajar, Michael; Dauncey, Paul; Davies, Gavin; Della Negra, Michel; Ferguson, William; Fulcher, Jonathan; Futyan, David; Gilbert, Andrew; Guneratne Bryer, Arlo; Hall, Geoffrey; Hatherell, Zoe; Hays, Jonathan; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Lyons, Louis; Magnan, Anne-Marie; Marrouche, Jad; Mathias, Bryn; Nandi, Robin; Nash, Jordan; Nikitenko, Alexander; Papageorgiou, Anastasios; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Pioppi, Michele; Raymond, David Mark; Rogerson, Samuel; Rose, Andrew; Ryan, Matthew John; Seez, Christopher; Sharp, Peter; Sparrow, Alex; Tapper, Alexander; Vazquez Acosta, Monica; Virdee, Tejinder; Wakefield, Stuart; Wardle, Nicholas; Whyntie, Tom; Chadwick, Matthew; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leslie, Dawn; Martin, William; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Hatakeyama, Kenichi; Liu, Hongxuan; Scarborough, Tara; Henderson, Conor; Rumerio, Paolo; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Heister, Arno; St John, Jason; Lawson, Philip; Lazic, Dragoslav; Rohlf, James; Sperka, David; Sulak, Lawrence; Alimena, Juliette; Bhattacharya, Saptaparna; Cutts, David; Ferapontov, Alexey; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Laird, Edward; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Nguyen, Duong; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Tsang, Ka Vang; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Dolen, James; Erbacher, Robin; Gardner, Michael; Houtz, Rachel; Ko, Winston; Kopecky, Alexandra; Lander, Richard; Mall, Orpheus; Miceli, Tia; Nelson, Randy; Pellett, Dave; Rutherford, Britney; Searle, Matthew; Smith, John; Squires, Michael; Tripathi, Mani; Vasquez Sierra, Ricardo; Andreev, Valeri; Cline, David; Cousins, Robert; Duris, Joseph; Erhan, Samim; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Plager, Charles; Rakness, Gregory; Schlein, Peter; Tucker, Jordan; Valuev, Vyacheslav; Weber, Matthias; Babb, John; Clare, Robert; Dinardo, Mauro Emanuele; Ellison, John Anthony; Gary, J William; Giordano, Ferdinando; Hanson, Gail; Jeng, Geng-Yuan; Liu, Hongliang; Long, Owen Rosser; Luthra, Arun; Nguyen, Harold; Paramesvaran, Sudarshan; Sturdy, Jared; Sumowidagdo, Suharyo; Wilken, Rachel; Wimpenny, Stephen; Andrews, Warren; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; Evans, David; Golf, Frank; Holzner, André; Kelley, Ryan; Lebourgeois, Matthew; Letts, James; Macneill, Ian; Mangano, Boris; Padhi, Sanjay; Palmer, Christopher; Petrucciani, Giovanni; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Sudano, Elizabeth; Tadel, Matevz; Tu, Yanjun; Vartak, Adish; Wasserbaech, Steven; Würthwein, Frank; Yagil, Avraham; Yoo, Jaehyeok; Barge, Derek; Bellan, Riccardo; Campagnari, Claudio; D'Alfonso, Mariarosaria; Danielson, Thomas; Flowers, Kristen; Geffert, Paul; Incandela, Joe; Justus, Christopher; Kalavase, Puneeth; Koay, Sue Ann; Kovalskyi, Dmytro; Krutelyov, Vyacheslav; Lowette, Steven; Mccoll, Nickolas; Pavlunin, Viktor; Rebassoo, Finn; Ribnik, Jacob; Richman, Jeffrey; Rossin, Roberto; Stuart, David; To, Wing; West, Christopher; Apresyan, Artur; Bornheim, Adolf; Chen, Yi; Di Marco, Emanuele; Duarte, Javier; Gataullin, Marat; Ma, Yousi; Mott, Alexander; Newman, Harvey B; Rogan, Christopher; Timciuc, Vladlen; Traczyk, Piotr; Veverka, Jan; Wilkinson, Richard; Yang, Yong; Zhu, Ren-Yuan; Akgun, Bora; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Jang, Dong Wook; Liu, Yueh-Feng; Paulini, Manfred; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Drell, Brian Robert; Edelmaier, Christopher; Ford, William T; Gaz, Alessandro; Heyburn, Bernadette; Luiggi Lopez, Eduardo; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Eggert, Nicholas; Gibbons, Lawrence Kent; Heltsley, Brian; Khukhunaishvili, Aleko; Kreis, Benjamin; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Ryd, Anders; Salvati, Emmanuele; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Vaughan, Jennifer; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bloch, Ingo; Burkett, Kevin; Butler, Joel Nathan; Chetluru, Vasundhara; Cheung, Harry; Chlebana, Frank; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Green, Dan; Gutsche, Oliver; Hanlon, Jim; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Kilminster, Benjamin; Klima, Boaz; Kunori, Shuichi; Kwan, Simon; Leonidopoulos, Christos; Lincoln, Don; Lipton, Ron; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Newman-Holmes, Catherine; O'Dell, Vivian; Prokofyev, Oleg; Sexton-Kennedy, Elizabeth; Sharma, Seema; Spalding, William J; Spiegel, Leonard; Tan, Ping; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitmore, Juliana; Wu, Weimin; Yang, Fan; Yumiceva, Francisco; Yun, Jae Chul; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Chen, Mingshui; Das, Souvik; De Gruttola, Michele; Di Giovanni, Gian Piero; Dobur, Didar; Drozdetskiy, Alexey; Field, Richard D; Fisher, Matthew; Fu, Yu; Furic, Ivan-Kresimir; Gartner, Joseph; Hugon, Justin; Kim, Bockjoo; Konigsberg, Jacobo; Korytov, Andrey; Kropivnitskaya, Anna; Kypreos, Theodore; Low, Jia Fu; Matchev, Konstantin; Milenovic, Predrag; Mitselmakher, Guenakh; Muniz, Lana; Remington, Ronald; Rinkevicius, Aurelijus; Sellers, Paul; Skhirtladze, Nikoloz; Snowball, Matthew; Yelton, John; Zakaria, Mohammed; Gaultney, Vanessa; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F; Prosper, Harrison; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Dorney, Brian; Hohlmann, Marcus; Kalakhety, Himali; Vodopiyanov, Igor; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Bucinskaite, Inga; Callner, Jeremy; Cavanaugh, Richard; Dragoiu, Cosmin; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Lacroix, Florent; Malek, Magdalena; O'Brien, Christine; Silkworth, Christopher; Strom, Derek; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Duru, Firdevs; Griffiths, Scott; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Newsom, Charles Ray; Norbeck, Edwin; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Tiras, Emrah; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bolognesi, Sara; Fehling, David; Giurgiu, Gavril; Gritsan, Andrei; Guo, Zijin; Hu, Guofan; Maksimovic, Petar; Rappoccio, Salvatore; Swartz, Morris; Whitbeck, Andrew; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Grachov, Oleg; Kenny Iii, Raymond Patrick; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Stringer, Robert; Tinti, Gemma; Wood, Jeffrey Scott; Zhukova, Victoria; Barfuss, Anne-Fleur; Bolton, Tim; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Shrestha, Shruti; Svintradze, Irakli; Gronberg, Jeffrey; Lange, David; Wright, Douglas; Baden, Drew; Boutemeur, Madjid; Calvert, Brian; Eno, Sarah Catherine; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kirn, Malina; Kolberg, Ted; Lu, Ying; Marionneau, Matthieu; Mignerey, Alice; Peterman, Alison; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C; Twedt, Elizabeth; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hahn, Kristan Allan; Kim, Yongsun; Klute, Markus; Krajczar, Krisztian; Li, Wei; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Sung, Kevin; Velicanu, Dragos; Wenger, Edward Allen; Wolf, Roger; Wyslouch, Bolek; Xie, Si; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Cooper, Seth; Dahmes, Bryan; De Benedetti, Abraham; Franzoni, Giovanni; Gude, Alexander; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Cremaldi, Lucien Marcus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Butt, Jamila; Claes, Daniel R; Dominguez, Aaron; Eads, Michael; Keller, Jason; Kravchenko, Ilya; Lazo-Flores, Jose; Malbouisson, Helena; Malik, Sudhir; Snow, Gregory R; Baur, Ulrich; Godshalk, Andrew; Iashvili, Ia; Jain, Supriya; Kharchilava, Avto; Kumar, Ashish; Shipkowski, Simon Peter; Smith, Kenneth; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Haley, Joseph; Nash, David; Trocino, Daniele; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Brinkerhoff, Andrew; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Morse, David Michael; Pearson, Tessa; Ruchti, Randy; Slaunwhite, Jason; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Bylsma, Ben; Durkin, Lloyd Stanley; Hill, Christopher; Hughes, Richard; Kotov, Khristian; Ling, Ta-Yung; Puigh, Darren; Rodenburg, Marissa; Vuosalo, Carl; Williams, Grayson; Winer, Brian L; Adam, Nadia; Berry, Edmund; Elmer, Peter; Gerbaudo, Davide; Halyo, Valerie; Hebda, Philip; Hegeman, Jeroen; Hunt, Adam; Jindal, Pratima; Lopes Pegna, David; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Raval, Amita; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Acosta, Jhon Gabriel; Brownson, Eric; Huang, Xing Tao; Lopez, Angel; Mendez, Hector; Oliveros, Sandra; Ramirez Vargas, Juan Eduardo; Zatserklyaniy, Andriy; Alagoz, Enver; Barnes, Virgil E; Benedetti, Daniele; Bolla, Gino; Bortoletto, Daniela; De Mattia, Marco; Everett, Adam; Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Kress, Matthew; Laasanen, Alvin T; Leonardo, Nuno; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Vidal Marono, Miguel; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Guragain, Samir; Parashar, Neeti; Adair, Antony; Boulahouache, Chaouki; Ecklund, Karl Matthew; Geurts, Frank JM; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Malik, Sarah; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Rekovic, Vladimir; Robles, Jorge; Rose, Keith; Salur, Sevil; Schnetzer, Steve; Seitz, Claudia; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Safonov, Alexei; Sakuma, Tai; Sengupta, Sinjini; Suarez, Indara; Tatarinov, Aysen; Toback, David; Akchurin, Nural; Damgov, Jordan; Dudero, Phillip Russell; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Libeiro, Terence; Roh, Youn; Volobouev, Igor; Appelt, Eric; Florez, Carlos; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Johnston, Cody; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Balazs, Michael; Boutle, Sarah; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Lin, Chuanzhe; Neu, Christopher; Wood, John; Yohay, Rachel; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sakharov, Alexandre; Anderson, Michael; Bachtis, Michail; Belknap, Donald; Borrello, Laura; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Gray, Lindsey; Grogg, Kira Suzanne; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Leonard, Jessica; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Palmonari, Francesco; Pierro, Giuseppe Antonio; Ross, Ian; Savin, Alexander; Smith, Wesley H; Swanson, Joshua
2012-01-01
The observation of a new b baryon via its strong decay into $\\Xi_{b}^- \\pi^+$ (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at $\\sqrt{s}$ = 7 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 inverse femtobarns. The known $\\Xi_b^-$ baryon is reconstructed via the decay chain $\\Xi_{b}^- \\to J/\\psi \\Xi^- \\to \\mu^+ \\mu^- \\Lambda^0 \\pi^-$, with $\\Lambda^0 \\to p \\pi^-$. A peak is observed in the distribution of the difference between the mass of the $\\Xi_{b}^- \\pi^+$ system and the sum of the masses of the $\\Xi_{b}^-$ and $\\pi^+$, with a significance exceeding five standard deviations. The mass difference of the peak is 14.84 +/- 0.74 (stat.) +/- 0.28 (syst.) MeV. The new state most likely corresponds to the $J^P=3/2^+$ companion of the $\\Xi_b$.
Bent by baryons: the low mass galaxy-halo relation
Sawala, Till; Fattahi, Azadeh; Navarro, Julio F; Bower, Richard G; Crain, Robert A; Vecchia, Claudio Dalla; Furlong, Michelle; Jenkins, Adrian; McCarthy, Ian G; Qu, Yan; Schaller, Matthieu; Schaye, Joop; Theuns, Tom
2014-01-01
The relation between galaxies and dark matter halos is of vital importance for evaluating theoretical predictions of structure formation and galaxy formation physics. We show that the widely used method of abundance matching based on dark matter only simulations fails at the low mass end because two of its underlying assumptions are broken: only a small fraction of low mass (below 10^9.5 solar masses) halos host a visible galaxy, and halos grow at a lower rate due to the effect of baryons. In this regime, reliance on dark matter only simulations for abundance matching is neither accurate nor self-consistent. We find that the reported discrepancy between observational estimates of the halo masses of dwarf galaxies and the values predicted by abundance matching does not point to a failure of LCDM, but simply to a failure to account for baryonic effects. Our results also imply that the Local Group contains only a few hundred observable galaxies in contrast with the thousands of faint dwarfs that abundance matchi...
Baryons Matter: Why Luminous Satellite Galaxies Have Reduced Central Masses
Zolotov, Adi; Willman, Beth; Governato, Fabio; Pontzen, Andrew; Christensen, Charlotte; Dekel, Avishai; Quinn, Tom; Shen, Sijing; Wadsley, James
2012-01-01
Using high resolution cosmological hydrodynamical simulations of Milky Way-massed disk galaxies, we demonstrate that supernovae feedback and tidal stripping lower the central masses of bright (-14 10^9 Msun, Mstar > 10^7 Msun) compared to DM-only simulations. The progenitors of the lower mass satellites are unable to maintain bursty star formation histories, due to both heating at reionization and gas loss from initial star forming events, preserving the steep inner density profile predicted by DM-only simulations. After infall, tidal stripping acts to further reduce the central densities of the luminous satellites, particularly those that enter with cored dark matter halos, increasing the discrepancy in the central masses predicted by baryon+DM and DM-only simulations. We show that DM-only simulations, which neglect the baryonic effects described in this work, produce denser satellites with larger central velocities. We provide a simple correction to the central DM mass predicted for satellites by DM-only s...
Precision measurement of the $\\Lambda_b^0$ baryon lifetime
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Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; 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; Zhokhov, A; Zhong, L; Zvyagin, A
2013-01-01
The ratio of the $\\Lambda_b^0$ baryon lifetime to that of the $\\overline{B}^0$ meson is measured using 1.0 fb$^{-1}$ of integrated luminosity in 7 TeV center-of-mass energy $pp$ collisions at the LHC. The $\\Lambda_b^0$ baryon is observed for the first time in the decay mode $\\Lambda_b^0 \\to J/\\psi p K^-$, while the $\\overline{B}^0$ meson decay used is the well known $\\overline{B}^0 \\to J/\\psi \\pi^+ K^-$ mode, where the $\\pi^+K^-$ mass is consistent with that of the $\\bar{K}^{*0}(892)$ meson. The ratio of lifetimes is measured to be $0.976\\pm0.012\\pm0.006$, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the $\\overline{B}^0$ meson lifetime, the $\\Lambda_b^0$ lifetime is found to be $1.482 \\pm 0.018 \\pm 0.012$ ps. In both cases the first uncertainty is statistical and the second systematic.
Semileptonic Decays of Heavy Omega Baryons in a Quark Model
Pervin, M; Capstick, S; Pervin, Muslema
2006-01-01
The semileptonic decays of $\\Omega_c$ and $\\Omega_b$ are treated in the framework of a constituent quark model developed in a previous paper on the semileptonic decays of heavy $\\Lambda$ baryons. Analytic results for the form factors for the decays to ground states and a number of excited states are evaluated. For $\\Omega_b$ to $\\Omega_c$ the form factors obtained are shown to satisfy the relations predicted at leading order in the heavy-quark effective theory at the non-recoil point. A modified fit of nonrelativistic and semirelativistic Hamiltonians generates configuration-mixed baryon wave functions from the known masses and the measured $\\lcle$ rate, with wave functions expanded in both harmonic oscillator and Sturmian bases. Decay rates of $\\ob$ to pairs of ground and excited $\\omc$ states related by heavy-quark symmetry calculated using these configuration-mixed wave functions are in the ratios expected from heavy-quark effective theory, to a good approximation. Our predictions for the semileptonic elas...
The Baryon Oscillation Spectroscopic Survey of SDSS-III
Dawson, Kyle S; Ahn, Christopher P; Anderson, Scott F; Aubourg, Eric; Bailey, Stephen; Barkhouser, Robert H; Bautista, Julian E; Beifiori, Alessandra; Berlind, Andreas A; Bhardwaj, Vaishali; Bizyaev, Dmitry; Blake, Cullen H; Blanton, Michael R; Blomqvist, Michael; Bolton, Adam S; Borde, Arnaud; Bovy, Jo; Brandt, W N; Brewington, Howard; Brinkmann, Jon; Brown, Peter J; Brownstein, Joel R; Bundy, Kevin; Busca, N G; Carithers, William; Carnero, Aurelio R; Carr, Michael A; Chen, Yanmei; Comparat, Johan; Connolly, Natalia; Cope, Frances; Croft, Rupert A C; Cuesta, Antonio J; da Costa, Luiz N; Davenport, James R A; Delubac, Timothee; de Putter, Roland; Dhital, Saurav; Ealet, Anne; Ebelke, Garrett L; Eisenstein, Daniel J; Escoffier, S; Fan, Xiaohui; Ak, N Filiz; Finley, Hayley; Font-Ribera, Andreu; Genova-Santos, R; Gunn, James E; Guo, Hong; Haggard, Daryl; Hall, Patrick B; Hamilton, Jean-Christophe; Harris, Ben; Harris, David W; Ho, Shirley; Hogg, David W; Holder, Diana; Honscheid, Klaus; Huehnerhoff, Joe; Jordan, Beatrice; Jordan, Wendell P; Kauffmann, Guinevere; Kazin, Eyal A; Kirkby, David; Klaene, Mark A; Kneib, Jean-Paul; Goff, Jean-Marc Le; Lee, Khee-Gan; Long, Daniel C; Loomis, Craig P; Lundgren, Britt; Lupton, Robert H; Maia, Marcio A G; Makler, Martin; Malanushenko, Elena; Malanushenko, Viktor; Mandelbaum, Rachel; Manera, Marc; Maraston, Claudia; Margala, Daniel; Masters, Karen L; McBride, Cameron K; McDonald, Patrick; McGreer, Ian D; Mena, Olga; Miralda-Escude, Jordi; Montero-Dorta, Antonio D; Montesano, Francesco; Muna, Demitri; Myers, Adam D; Naugle, Tracy; Nichol, Robert C; Noterdaeme, Pasquier; Olmstead, Matthew D; Oravetz, Audrey; Oravetz, Daniel J; Owen, Russell; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K; Paris, Isabelle; Percival, Will J; Perez-Fournon, Ismael; Perez-Rafols, Ignasi; Petitjean, Patrick; Pfaffenberger, Robert; Pforr, Janine; Pieri, Matthew M; Prada, Francisco; Price-Whelan, Adrian M; Raddick, M Jordan; Rebolo, Rafael; Rich, James; Richards, Gordon T; Rockosi, Constance M; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rossi, Graziano; Rubino-Martin, J A; Samushia, Lado; Sanchez, Ariel G; Sayres, Conor; Schmidt, Sarah J; Schneider, Donald P; Scoccola, C G; Seo, Hee-Jong; Shelden, Alaina; Sheldon, Erin; Shen, Yue; Shu, Yiping; Slosar, Anze; Smee, Stephen A; Snedden, Stephanie A; Stauffer, Fritz; Steele, Oliver; Strauss, Michael A; Suzuki, Nao; Swanson, Molly E C; Tal, Tomer; Tanaka, Masayuki; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Tremonti, Christy A; Magana, M Vargas; Verde, Licia; Viel, Matteo; Wake, David A; Watson, Mike; Weaver, Benjamin A; Weinberg, David H; Weiner, Benjamin J; West, Andrew A; White, Martin; Wood-Vasey, W M; Yeche, Christophe; Zehavi, Idit; Zhao, Gong-Bo; Zheng, Zheng
2012-01-01
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses luminous galaxies to measure BAO to redshifts z<0.7 and observations of neutral hydrogen in the Lyman alpha forest in quasar spectra to constrain BAO over the redshift range 2.15
Electroproduction of baryon-meson states and strangeness suppression
Santopinto, E.; García-Tecocoatzi, H.; Bijker, R.
2016-08-01
We describe the electroproduction ratios of baryon-meson states from nucleon, inferring from the sea quarks in the 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: ΛK+, Σ* K, ΣK, pπ0, and nπ+. 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 tests of different predictions concerning the structure of nucleon and its sea quarks helping to solve an outstanding problem. Finally, we compute the so called strangeness suppression factor, λs, that is the suppression of strange quark-antiquark pairs compared to nonstrange pairs, and we found that our finding with this simple extension of the quark model is in good agreement with the results of JLab and CERN experiments.
Baryons, their interactions and the chiral symmetry of QCD
Glozman, L Ya
1997-01-01
An implication of the spontaneous chiral symmetry breaking in QCD is that at low energy and resolution there appear quasiparticles - constituent quarks and Goldstone bosons. Thus, light and strange baryons should be considered as systems of three constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons between the constituent quarks. We show how the flavor-spin structure and sign of the short-range part of the Goldstone boson exchange interaction 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. We present a unified description of light and strange baryon spectra calculated in a semirelativistic framework. It is demonstrated that the same short-range part of Goldstone boson exchange also induces strong short-range repulsion in $NN$ system when the latter is treated as $6Q$ system. Thus, all main ingredients of $NN$ interaction a...
Streaming Velocities and the Baryon Acoustic Oscillation Scale.
Blazek, Jonathan A; McEwen, Joseph E; Hirata, Christopher M
2016-03-25
At the epoch of decoupling, cosmic baryons had supersonic velocities relative to the dark matter that were coherent on large scales. These velocities subsequently slow the growth of small-scale structure and, via feedback processes, can influence the formation of larger galaxies. We examine the effect of streaming velocities on the galaxy correlation function, including all leading-order contributions for the first time. We find that the impact on the baryon acoustic oscillation (BAO) peak is dramatically enhanced (by a factor of ∼5) over the results of previous investigations, with the primary new effect due to advection: if a galaxy retains memory of the primordial streaming velocity, it does so at its Lagrangian, rather than Eulerian, position. Since correlations in the streaming velocity change rapidly at the BAO scale, this advection term can cause a significant shift in the observed BAO position. If streaming velocities impact tracer density at the 1% level, compared to the linear bias, the recovered BAO scale is shifted by approximately 0.5%. This new effect, which is required to preserve Galilean invariance, greatly increases the importance of including streaming velocities in the analysis of upcoming BAO measurements and opens a new window to the astrophysics of galaxy formation.
The small scatter of the baryonic Tully-Fisher relation
Lelli, Federico; Schombert, James M
2015-01-01
In a LCDM cosmology, the baryonic Tully-Fisher relation (BTFR) is expected to show significant intrinsic scatter resulting from the mass-concentration relation of dark matter halos and the baryonic-to-halo mass ratio. We study the BTFR using a sample of 118 disc galaxies (spirals and irregulars) with data of the highest quality: extended HI rotation curves (tracing the outer velocity) and Spitzer photometry at 3.6 $\\mu$m (tracing the stellar mass). Assuming that the stellar mass-to-light ratio (M*/L) is nearly constant at 3.6 $\\mu$m, we find that the scatter, slope, and normalization of the BTFR systematically vary with the adopted M*/L. The observed scatter is minimized for M*/L > 0.5, corresponding to nearly maximal discs in high-surface-brightness galaxies and BTFR slopes close to ~4. For any reasonable value of M*/L, the intrinsic scatter is ~0.1 dex, below general LCDM expectations. The residuals show no correlations with galaxy structural parameters (radius or surface brightness), contrary to the predic...
A Study of Double-Charm and Charm-Strange Baryons inElectron-Positron Annihilations
Energy Technology Data Exchange (ETDEWEB)
Edwards, Adam J.; /SLAC
2007-10-15
In this dissertation I describe a study of double-charm and charm-strange baryons based on data collected with the BABAR Detector at the Stanford Linear Accelerator Center. In this study I search for new baryons and make precise measurements of their properties and decay modes. I seek to verify and expand upon double-charm and charm-strange baryon observations made by other experiments. The BABAR Detector is used to measure subatomic particles that are produced at the PEP-II storage rings. I analyze approximately 300 million e+e- {yields} c{bar c} events in a search for the production of double-charm baryons. I search for the double-charm baryons {Xi}{sup +}{sub cc} (containing the quarks ccd) and {Xi}{sup ++}{sub cc} (ccu) in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +} and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}{pi}{sup +}, respectively. No statistically significant signals for their production are found, and upper limits on their production are determined. Statistically significant signals for excited charm-strange baryons are observed with my analysis of approximately 500 million e+e- {yields} c{bar c} events. The charged charm-strange baryons {Xi}{sub c}(2970){sup +}, {Xi}{sub c}(3055){sup +}, {Xi}{sub c}(3123){sup +} are found in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}, the same decay mode used in the {Xi}{sup +}{sub cc} search. The neutral charm-strange baryon {Xi}{sub c}(3077){sup 0} is observed in decays to {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}. I also search for excited charm-strange baryon decays to {Lambda}{sup +}{sub c}K{sub 8}, {Lambda}{sup +}{sub c}K{sup -}, {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}{pi}{sup +}, and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup -}{pi}{sup +}. No significant charm-strange baryon signals a f h these decay modes. For each excited charm-strange baryon state that I observe, I measure its mass, natural width (lifetime), and production rate. The properties of these excited charm-strange baryons and their
Supersymmetric Meson-Baryon Properties of QCD from Light-Front Holography and Superconformal Algebra
Brodsky, Stanley J
2016-01-01
A remarkable feature of QCD is that the mass scale which controls color confinement and hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. Applying the same procedure to the light-front Hamiltonian leads to a unique confinement potential $\\kappa^4 \\zeta^2$ for mesons, where $\\zeta$ is the LF radial variable conjugate to the invariant mass. The same result, including spin terms, is obtained using light-front holography, the duality between the front form and AdS$_5,$ if one modifies the action by the dilaton $e^{\\kappa^2 z^2}$ in the fifth dimension $z$. Generalizing this procedure using superconformal algebra, leads to a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric rel...
Effect of pre-existing baryon inhomogeneities on the dynamics of quark–hadron transition
Indian Academy of Sciences (India)
Soma Sanyal
2003-11-01
Baryon number inhomogeneities may be generated during the epoch when the baryon asymmetry of the universe is produced, e.g. at the electroweak phase transition. These lumps will have a lower temperature than the background. Also the value of c will be different in these regions. Since a ﬁrst-order quark–hadron (Q–H) transition is susceptible to small changes in temperature, we investigate the effect of the presence of such baryonic lumps on the dynamics of the Q–H transition. We ﬁnd that the phase transition is delayed in these lumps for signiﬁcant overdensities. Consequently, we argue that baryon concentration in these regions grows by the end of the transition. We mention some models which may give rise to such high baryon overdensities before the Q–H transition.
Skyrmion Black Hole Hair: Conservation of Baryon Number by Black Holes and Observable Manifestations
Dvali, Gia
2016-01-01
We show that the existence of black holes with classical skyrmion hair invalidates standard proofs that global charges, such as the baryon number, cannot be conserved by a black hole. By carefully analyzing the standard arguments based on a Gedankenexperiment in which a black hole is seemingly-unable to return the baryon number that it swallowed, we identify inconsistencies in this reasoning, which does not take into the account neither the existence of skyrmion black holes nor the baryon/skyrmion correspondence. We then perform a refined Gedankenexperiment by incorporating the new knowledge and show that no contradiction with conservation of baryon number takes place at any stage of black hole evolution. Our analysis also indicates no conflict between semi-classical black holes and the existence of baryonic gauge interaction arbitrarily-weaker than gravity. Next, we study classical cross sections of a minimally-coupled massless probe scalar field scattered by a skyrmion black hole. We investigate how the sky...
Semileptonic bc to cc Baryon Decay and Heavy Quark Spin Symmetry
Flynn, Jonathan M
2007-01-01
We study the semileptonic decays of the lowest-lying bc baryons to the lowest-lying cc baryons (Xi_{bc}^{(\\prime*)}--> Xi_{cc}^{(*)} and Omega_{bc}^{(\\prime*)}--> Omega_{cc}^{(*)}), in the limit m_b, m_c >> Lambda_{QCD} and close to the zero recoil point. The separate heavy quark spin symmetries make it possible to describe all these decays using a single form factor. We recover results derived previously by White and Savage in a manner which we think is more straightforward and parallels the method applied later to study Bc semileptonic decays. We further discuss the resemblence between the bc baryon decays and those of Bc mesons to eta_c and J/\\psi mesons and comment on the relation between the slopes of the single functions describing each set of decays. Our results can straightforwardly be applied to the decays of bb baryons to bc baryons.
Masses of doubly charmed baryons in the extended on-mass-shell renormalization scheme
Sun, Zhi-Feng
2016-01-01
In this work, we investigate the mass corrections of the doubly charmed baryons up to $N^2LO$ in the extended-on-mass-shell (EOMS) renormalization scheme, comparing with the results of heavy baryon chiral perturbation theory. We find that the terms from the heavy baryon approach are a subset of those obtained in the EOMS scheme. By fitting the lattice data, we can determine the parameters $\\tilde{m}$, $\\alpha$, $c_1$ and $c_7$ from the Lagrangian, while in the heavy baryon approach no information on $c_1$ can be obtained from the baryons mass. Correspondingly, the masses of $m_{\\Xi_{cc}}$ and $m_{\\Omega_{cc}}$ are predicted, in the EOMS scheme, extrapolating the results from different values of the charm quark and the pion masses of the lattice QCD calculations.
CP Violating Polarization Asymmetry in Charmless Two-Body Decays of Beauty Baryons
He, Min; Li, Guan-Nan
2015-01-01
Several baryons containing a heavy b-quark, the b-baryons, have been discovered. The charmless two-body decays of b-baryons can provide a new platform for CP violating studies in a similar way as charmless two-body decays of B-meson. In b-baryon decays there are new CP violating observable related to baryon polarization. We show that in the flavor $SU(3)$ limit there exist relations involve different combinations of the decay amplitudes compared with those in CP violating rate asymmetry. These new relations therefore provide interesting tests for the mechanism of CP in the standard model (SM) and flavor $SU(3)$ symmetry. Future data from LHCb can test these relations.
Aharonov–Bohm protection of black hole's baryon/skyrmion hair
Directory of Open Access Journals (Sweden)
Gia Dvali
2017-05-01
Full Text Available The baryon/skyrmion correspondence implies that the baryon number is encoded into a topological surface integral. Under certain conditions that we clarify, this surface integral can be measured by an asymptotic observer in form of an Aharonov–Bohm phase-shift in an experiment in which the skyrmion passes through a loop of a probe string. In such a setup the baryon/skyrmion number must be respected by black holes, despite the fact that it produces no long-range classical field. If initially swallowed by a black hole, the baryon number must resurface in form of a classical skyrmion hair, after the black hole evaporates below a certain critical size. Needless to say, the respect of the baryon number by black holes is expected to have potentially-interesting astrophysical consequences.
Baryon number segregation at the end of the cosmological quark-hadron transition
Rezzolla, L
1996-01-01
One of the most interesting questions regarding a possible first order cosmological quark--hadron phase transition concerns the final fate of the baryon number contained within the disconnected quark regions at the end of the transition. We here present a detailed investigation of the hydrodynamical evolution of an evaporating quark drop, using a multi-component fluid description to follow the mechanisms of baryon number segregation. With this approach, we are able to take account of the simultaneous effects of baryon number flux suppression at the phase interface, entropy extraction by means of particles having long mean-free-paths, and baryon number diffusion. A range of computations has been performed to investigate the permitted parameter-space and this has shown that significant baryon number concentrations, perhaps even up to densities above that of nuclear matter, represent an inevitable outcome within this scenario.
The Effect of Central Baryonic Cores in Dark Halos on the Evaluation of Strong Lensing Probabilities
Institute of Scientific and Technical Information of China (English)
Jie Wang
2004-01-01
We present an estimate of the strong lensing probability by dark halos, with emphasis on the role of the baryonic matter arising purely from radiative cooling. We treat the contribution of the cooled baryons optimistically with all the cooled baryons confined within a central core, and including no feedback process from stellar evolution. Our two-component model provides a strong lensing probability that is in good agreement with the observed distribution of multiple images of quasars, provided that the cooled baryons are deposited within a spherical region of radius of 0.1 times the virial radius and follow an isothermal profile. It is pointed out that strong lensing may be used as an additional probe of baryon physics in dark halos though this may meanwhile complicate the test of the inner density profiles of dark matter in halos using the observed strong lensing probability.
Aharonov-Bohm protection of black hole's baryon/skyrmion hair
Dvali, Gia
2016-01-01
The baryon/skyrmion correspondence implies that the baryon number is encoded into a topological surface integral. Under certain conditions that we clarify, this surface integral can be measured by an asymptotic observer in form of an Aharonov-Bohm phase-shift in an experiment in which the skyrmion passes through a loop of a probe string. In such a setup the baryon/skyrmion number must be respected by black holes, despite the fact that it produces no long-range classical field. If initially swallowed by a black hole, the baryon number must resurface in form of a classical skyrmion hair, after the black hole evaporates below a certain critical size. Needless to say, the respect of the baryon number by black holes is expected to have potentially-interesting astrophysical consequences.
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.)
A model of charmed baryon-nucleon potential and 2- and 3-body bound states with charmed baryon
Maeda, Saori; Yokota, Akira; Hiyama, Emiko; Liu, Yan-Rui
2015-01-01
Potential models of the interaction between a charmed baryon ($Y_c$) and the nucleon ($N$) are constructed on the basis of a long-range meson ($\\pi$ and $\\sigma$) exchange potential as well as a short-distance quark exchange interaction. The quark cluster model is used to evaluate the short-range repulsion between $Y_c$ and $N$, while the meson exchange potentials are modified by a form factor at short distances. We determine the cutoff parameters of the form factors so as to fit the $NN$ scattering data with the same approach. The ground state charmed baryons, $\\Lambda_c$, $\\Sigma_c$ and $\\Sigma_c^*$, are included as $Y_c$, and channel couplings of relevant $Y_c N$ channels are taken into account. We propose four sets of parameters (a -- d), among which the most attractive potential (d) predicts bound $\\Lambda_c N$ $J^\\pi= 0^+$ and $1^+$ states. In order to apply the potential to a many-body problem, we construct an effective $\\Lambda_c N$ one-channel potential for the parameter set (d). It is applied to the...
a Study of the Semileptonic Decay Properties of Charmed Baryons
van de Water, Richard George
1993-01-01
The first significant observations of the semileptonic decay of the charmed baryons Lambda_sp {c}{+} and Xi _sp{c}{0} have been made using the ARGUS detector at the e^+e^ - storage ring DORIS II at DESY. The ARGUS detector is a 4pi magnetic solenoidal detector used to observe e^+e^- annihilations at a center-of-mass energy around 10.4 GeV. The semileptonic decay modes studied are Lambda_sp{c}{+}to Lambda l^+X, Lambda_sp {c}{+} to Lambda^*l^+X, and Xi_sp{c}{0} to Xi^-l^+X where l^+ is an e ^+ or a mu^+, and X is any low mass neutral particle combination containing a neutrino. Because the neutrino cannot be detected in this experiment great care must be taken in considering all possible sources of contributing background. After this background subtraction the cross section times branching ratio were determined to be,eqalign {&sigma(e^+e^-toLambda _sp{c}{+}X)cdot BR(Lambda _sp{c}{+}toLambda l^+X) = 4.15 +/- 1.03 +/- 1.18 pb cr&sigma(e^+e^-toXi _sp{c}{0}X)cdot BR(Xi _sp{c}{0}toXi^ -l^+X) = 0.74 +/- 0.24 +/- 0.09 pb cr&sigma(e^+e^-toLambda _sp{c}{+}X)cdot BR(Lambda _sp{c}{+}to(Sigma(1385) pi)^0 e^+X)=cr&sk{130 } 1.10 +/- 0.95 +/- 0.29 pb.cr }The branching ratios can be extracted from these numbers and compared with theoretical calculations. These measurements are found to be consistent with some, but not all charmed baryon semileptonic decay models. Comparison of the shape of the Lambda l^+ mass distribution from Lambda _sp{c}{+}toLambda l^+nu_{l} decays with those of the Heavy Quark Effective Theory (HQET) model calculations of Korner and Kramer determined the ratio of the HQET form factors to be R_{f } = f_2/f_1 = +3.2_sp {-2.2}{+infty}. Also, observation of the polarization angular distribution of the Lambda daughter baryon from these decays found alpha_{Lambda _{c}} = -0.91 +/- 0.42 +/- 0.25 for events in the mass region 1.85 < M(Lambda l^+) < 2.20 GeV/c^2. This last measurement is in agreement with the HQET predictions of alpha _{Lambda_{c}} to -1 in the limit q^2
Enrichment study of hot intra-cluster gas through X-ray spectroscopy
Plaa, J. de
2007-01-01
Enrichment study of hot intra-cluster gas through X-ray spectroscopy Clouds of hot X-ray emitting gas associated with clusters of galaxies are the biggest aggregates of baryons that we know, except for the cosmic web. A typical cloud contains the nuclear-fusion products of billions of supernovae. Th
Energy Technology Data Exchange (ETDEWEB)
Aston, D.; Awaji, N.; Bienz, T.; Bird, F.; D' Amore, J.; Dunwoodie, W.; Endorf, R.; Fujii, K.; Hayashiii, H.; Iwata, S.
1989-02-01
Data demonstrating the existence of two ..cap omega../sup */minus// resonances produced in K/sup /minus//p interactions at 11 GeV/c in the LASS spectrometer are presented. The first state is seen in the ..xi../sup */degree//minus// decay channel with mass 2253 +- 13 MeV/c/sup 2/ and width 81 +- 38 MeV/c/sup 2/, and the second in the ..cap omega../sup /minus//..pi../sup +/..pi../sup /minus// system with mass 2474 +- 12 and width 72 +- 33 MeV/c/sup 2/. Inclusive cross sections corresponding to these decays corrected for unseen charge modes are estimated to be respectively 630 +- 180 and 290 +- 90 nb, respectively. 10 refs., 16 figs., 1 tab.
The baryon acoustic oscillation peak: a flexible standard ruler
Roukema, Boudewijn F
2016-01-01
For about a decade, the baryon acoustic oscillation (BAO) peak at about 105 Mpc/h has provided a standard ruler test of the LCDM cosmological model, a member of the Friedmann--Lemaitre--Robertson--Walker (FLRW) family of cosmological models---according to which comoving space is rigid. However, general relativity does not require comoving space to be rigid. During the virialisation epoch, when the most massive structures form by gravitational collapse, it should be expected that comoving space evolves inhomogeneous curvature as structure grows. The BAO peak standard ruler should also follow this inhomogeneous evolution if the comoving rigidity assumption is false. This "standard" ruler has now been detected to be flexible, as expected under general relativity.
Baryon Acoustic Oscillation Intensity Mapping of Dark Energy
Chang, Tzu-Ching; Pen, Ue-Li; Peterson, Jeffrey B.; McDonald, Patrick
2008-03-01
The expansion of the Universe appears to be accelerating, and the mysterious antigravity agent of this acceleration has been called “dark energy.” To measure the dynamics of dark energy, baryon acoustic oscillations (BAO) can be used. Previous discussions of the BAO dark energy test have focused on direct measurements of redshifts of as many as 109 individual galaxies, by observing the 21 cm line or by detecting optical emission. Here we show how the study of acoustic oscillation in the 21 cm brightness can be accomplished by economical three-dimensional intensity mapping. If our estimates gain acceptance they may be the starting point for a new class of dark energy experiments dedicated to large angular scale mapping of the radio sky, shedding light on dark energy.
Hypermagnetic gyrotropy, inflation and the baryon asymmetry of the Universe
Giovannini, Massimo
2015-01-01
We investigate the production of the hypermagnetic gyrotropy when the electric and magnetic gauge couplings evolve at different rates, as it happens in the the relativistic theory of the Van der Waals forces. If a pseudo-scalar interaction breaks the duality symmetry of the corresponding equations, the gyrotropic configurations of the hypermagnetic fields can be amplified from the vacuum during an inflationary stage of expansion. After charting the parameter space of the model in terms of the rates of evolution of the magnetic and electric gauge couplings, we identify the regions where the gyrotropy is sufficiently intense to seed the baryon asymmetry of the Universe at the electroweak epoch while the backreaction constraints, the strong coupling bounds and the other astrophysical limits are concurrently satisfied.
Direct observation of the strange b baryon Xi_b^{-}
Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, C; Clement, B; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, G; De, K; De Jong, S J; de Jong, P; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutíerrez, P; Gutíerrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Yu M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kühl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G L; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajícek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merekov, Y P; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Pangilinan, M; Panov, G; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perea, P M; Peters, K; Peters, Y; Petroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Polozov, P; Pompo, A; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S D; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F K; Robinson, S; Rodrigues, R F; Royon, C; Rozhdestvenski, A; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A F S; Savage, G; Sawyer, L; Scanlon, T; Schaile, A D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schliephake, T; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sen-Gupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Simák, V; Sirotenko, V I; Skubic, P L; Slattery, P F; Smirnov, D; Smith, R P; Snow, J; Snow, G R; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Strauss, E; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Tanasijczuk, A; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, S; Uvarov, L; Uzunyan, S; Vachon, B; Van den Berg, P J; van Eijk, B; Van Kooten, R; Van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Vertogradova, Y; Verzocchi, M; Villeneuve-Séguier, F; Vint, P; Vokac, P; Von Törne, E; Voutilainen, M; Vreeswijk, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L; Warchol, J; Watts, G; Wayne, M; Weber, M; Weber, G; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, J; Yu, C; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G
2007-01-01
We report the first direct observation of the strange b baryon Xi_b^{-}. We reconstruct the decay Xi_b^{-} to J/psi Xi^{-}, with J/psi to dimuons and Xi^{-} to Lambda pion, in ppbar collisions at sqrt(s) = 1.96 TeV. Using 1.3 fb^{-1} of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat.)+ 1.9/-0.4(syst.) Xi_b^{-} candidates at a mass of 5.774 +/- 0.011(stat.) +/- 0.015 (syst.) GeV. The significance of the observed signal is 5.5 sigmas, equivalent to a probability of 3.3 X 10^{-8} of it arising from a background fluctuation. Normalizing to the decay Lambda_b to J/psi Lambda, we measure the relative rate to be 0.28 +/- 0.09(stat.)+ 0.09/-0.08 (syst.).
Can the Baryon Asymmetry Arise From Initial Conditions?
Krnjaic, Gordan
2016-01-01
In this letter, we quantify the challenge of explaining the baryon asymmetry using initial conditions in a universe that undergoes inflation. Contrary to lore, we find that such an explanation is possible if net $B-L$ number is stored in a light bosonic field with hyper-Planckian initial displacement and a delicately chosen field velocity prior to inflation. However, such a construction may require extremely tuned coupling constants to ensure that this asymmetry is viably communicated to the Standard Model after reheating; the large field displacement required to overcome inflationary dilution must not induce masses for Standard Model particles or generate dangerous washout processes. While these features are inelegant, this counterexample nonetheless shows that there is no theorem against such an explanation. We also comment on potential observables in the double $\\beta$-decay spectrum and on model variations that may allow for more natural realizations.
Baryon Acoustic Oscillations in the Lyman Alpha Forest
Norman, Michael L; Harkness, Robert
2009-01-01
We use hydrodynamic cosmological simulations in a (600 Mpc)^3 volume to study the observability of baryon acoustic oscillations (BAO) in the intergalactic medium as probed by Lyman alpha forest (LAF) absorption. The large scale separation between the wavelength of the BAO mode (~150 Mpc) and the size of LAF absorbers (~100 kpc) makes this a numerically challenging problem. We report on several 2048^3 simulations of the LAF using the ENZO code. We adopt WMAP5 concordance cosmological parameters and power spectrum including BAO perturbations. 5000 synthetic HI absorption line spectra are generated randomly piercing the box face. We calculate the cross-correlation function between widely separated pairs. We detect the BAO signal at z=3 where theory predicts to moderate statistical significance.
Strange b baryon production and lifetime in Z decays
Buskulic, Damir; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; 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; Padilla, C; Park, I 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; Lutters, G; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; 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; Teixeira-Dias, P; 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; 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; Giehl, I; 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; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Schune, M H; Simion, S; Veillet, J J; Videau, I; Zerwas, D; 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; Palla, Fabrizio; 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; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Büscher, V; Cowan, G D; Grupen, Claus; 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; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G
1996-01-01
In a data sample of approximately four million hadronic Z decays recorded with the ALEPH detector from 1990 to 1995, a search for the strange b baryon Xi_b is performed with a study of Xi-lepton correlations. Forty-four events with same sign Xi- l- combinations are found whereas 8.4 are expected based on on the rate of opposite sign Xi- l+ combinations. This significant excess is interpreted as evidence for Xi_b semileptonic decays. The measured product branching ratio is: Br( b -> Xi_b) Br( Xi_b -> Xc X l- nu) Br( Xc -> Xi- X') = (5.4 +/- 1.1(stat) +/- 0.8(syst) ) 10**-4 per lepton species, averaged over electrons and muons, with Xc a charmed baryo\\ n. The Xi_b lifetime is measured to be : tau = 1.35 (+0.37 -0.28 (stat)) (+0.15 -0.17 (syst)) ps.
Dark and baryonic matter in the MareNostrum Universe
Gottlöber, S; Khalatyan, A; Sevilla, R; Turchaninov, V I
2006-01-01
We report some results from one of the largest hydrodynamical cosmological simulations of large scale structures that has been done up to date. The MareNostrum Universe SPH simulation consists of 2 billion particles (2 times 1024^3) in a cubic box of 500 h^-1 Mpc on a side. This simulation has been done in the MareNostrum parallel supercomputer at the Barcelona SuperComputer Center. Due to the large simulated volume and good mass resolution, our simulated catalog of dark matter halos comprises more than half a million objects with masses larger than a typical Milky Way galaxy halo. From this dataset we have studied several statistical properties such as the evolution of the halo mass function, the void distribution, the shapes of dark and gas halos and the large scale distribution of baryons.
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.)
Can the Baryon Asymmetry Arise From Initial Conditions?
Energy Technology Data Exchange (ETDEWEB)
Krnjaic, Gordan [Fermilab
2016-06-16
In this letter, we quantify the challenge of explaining the baryon asymmetry using initial conditions in a universe that undergoes inflation. Contrary to lore, we find that such an explanation is possible if net $B-L$ number is stored in a light bosonic field with hyper-Planckian initial displacement and a delicately chosen field velocity prior to inflation. However, such a construction may require extremely tuned coupling constants to ensure that this asymmetry is viably communicated to the Standard Model after reheating; the large field displacement required to overcome inflationary dilution must not induce masses for Standard Model particles or generate dangerous washout processes. While these features are inelegant, this counterexample nonetheless shows that there is no theorem against such an explanation. We also comment on potential observables in the double $\\beta$-decay spectrum and on model variations that may allow for more natural realizations.
Charmed baryon isodoublet mass splitting in quantum chromodynamics revitalized
Sinha, S. N.; Sinha, S. M.; Rahman, M.; Kim, D. Y.
1989-02-01
We calculate the isodoublet mass splitting of charmed baryons in the quark model in QCD, which includes the relativistic correction and the explicit use of running QCD coupling constants with flavors. The model was applied and tested in the past for the calculations of isodoublet mass splittings of several hadrons. Our theoretical result ( Δmth( Σc++- Σc0)≅1.5±0.2 MeV) is in agteement with the recent experimental result ( Δmex( Σc++- Σc0)=1.2±0.7±0.3 MeV) by the ARGUS Collaboration at the DORIS II storage ring.
Another baryon miracle? Testing solutions to the "missing dwarfs" problem
Trujillo-Gomez, Sebastian; Papastergis, Emmanouil; Reed, Darren S; Lake, George
2016-01-01
No explanation exists so far for the observed dearth of dwarf galaxies in the local universe compared to the large number of dark matter halos predicted by $\\Lambda$CDM. Although attempts have been made to attribute the discrepancy to observational systematics, this would require an extreme modification of the density profiles of haloes through baryonic processes. In this paper we perform a systematic evaluation of the uncertainties affecting the measurement of DM halo abundance using galaxy kinematics. Including observational systematics and modelling uncertainties, we derive the abundance of galaxies as a function of maximum circular velocity --a direct probe of mass-- from the observed line-of-sight velocity function in the Local Volume. This provides a direct means of comparing the predictions of theoretical models and simulations (including nonstandard cosmologies and novel galaxy formation physics) to the observational constraints. The new "galactic $V_{max}$" function is steeper than the line-of-sight ...
Measuring baryon acoustic oscillations with future SKA surveys
Bull, Philip; Raccanelli, Alvise; Blake, Chris; Ferreira, Pedro G; Santos, Mario G; Schwarz, Dominik J
2015-01-01
The imprint of baryon acoustic oscillations (BAO) in large-scale structure can be used as a standard ruler for mapping out the cosmic expansion history, and hence for testing cosmological models. In this article we briefly describe the scientific background to the BAO technique, and forecast the potential of the Phase 1 and 2 SKA telescopes to perform BAO surveys using both galaxy catalogues and intensity mapping, assessing their competitiveness with current and future optical galaxy surveys. We find that a 25,000 sq. deg. intensity mapping survey on a Phase 1 array will preferentially constrain the radial BAO, providing a highly competitive 2% constraint on the expansion rate at z ~ 2. A 30,000 sq. deg. galaxy redshift survey on SKA2 will outperform all other planned experiments for z < 1.4.
\\pi N scattering in relativistic baryon chiral perturbation theory revisited
Alarcon, J M; Oller, J A; Alvarez-Ruso, L
2011-01-01
We have analyzed pion-nucleon scattering using the manifestly relativistic covariant framework of Infrared Regularization up to {\\cal O}(q^3) in the chiral expansion, where q is a generic small momentum. We describe the low-energy phase shifts with a similar quality as previously achieved with Heavy Baryon Chiral Perturbation Theory, \\sqrt{s}\\lesssim1.14 GeV. New values are provided for the {\\cal O}(q^2) and {\\cal O}(q^3) low-energy constants, which are compared with previous determinations. This is also the case for the scattering lengths and volumes. Finally, we have unitarized the previous amplitudes and as a result the energy range where data are reproduced increases significantly.
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.
Unquenched QCD Dirac operator spectra at nonzero baryon chemical potential
Energy Technology Data Exchange (ETDEWEB)
Akemann, G. [Department of Mathematical Sciences, Brunel University West London, Uxbridge UB8 3PH (United Kingdom); Osborn, J.C. [Physics Department, Boston University, Boston, MA 02215 (United States); Splittorff, K. [Nordita, Blegdamsvej 17, DK-2100, Copenhagen O (Denmark)]. E-mail: split@alf.nbi.dk; Verbaarschot, J.J.M. [Department of Physics and Astronomy, SUNY, Stony Brook, NY 11794 (United States)
2005-04-18
The microscopic spectral density of the QCD Dirac operator at nonzero baryon chemical potential for an arbitrary number of quark flavors was derived recently from a random matrix model with the global symmetries of QCD. In this paper we show that these results and extensions thereof can be obtained from the replica limit of a Toda lattice equation. This naturally leads to a factorized form into bosonic and fermionic QCD-like partition functions. In the microscopic limit these partition functions are given by the static limit of a chiral Lagrangian that follows from the symmetry breaking pattern. In particular, we elucidate the role of the singularity of the bosonic partition function in the orthogonal polynomials approach. A detailed discussion of the spectral density for one and two flavors is given.
A Precision Measurement of the Lambda_c Baryon Mass
Energy Technology Data Exchange (ETDEWEB)
Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B.
2005-07-06
The {Lambda}{sub c}{sup +} baryon mass is measured using {Lambda}{sub c}{sup +} {yields} {Lambda}K{sub S}{sup 0}K{sup +} and {Lambda}{sub c}{sup +} {yields} {Sigma}{sup 0}K{sub S}{sup 0}K{sup +} decays reconstructed in 232 fb{sup -1} of data collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. The {Lambda}{sub c}{sup +} mass is measured to be 2286.46 {+-} 0.14 MeV/c{sup 2}. The dominant systematic uncertainties arise from the amount of material in the tracking volume and from the magnetic field strength.
Search for the doubly charmed baryon $\\Xi_{cc}^+$
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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; Yang, Z; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A
2013-01-01
A search for the doubly charmed baryon $\\Xi_{cc}^{+}$ in the decay mode $\\Xi_{cc}^{+} \\to \\Lambda_c^+ K^- \\pi^+$ is performed with a data sample, corresponding to an integrated luminosity of 0.65 fb$^{-1}$, of $pp$ collisions recorded at a centre-of-mass energy of 7 TeV. No significant signal is found in the mass range 3300--3800 MeV$/c^2$. Upper limits at the 95\\% confidence level on the ratio of the $\\Xi_{cc}^{+}$ production cross-section times branching fraction to that of the $\\Lambda_c^+$, $R$, are given as a function of the $\\Xi_{cc}^{+}$ mass and lifetime. The largest upper limits range from $R<1.5 \\times 10^{-2}$ for a lifetime of 100 fs to $R<3.9 \\times 10^{-4}$ for a lifetime of 400 fs.
Efficient Reconstruction of Linear Baryon Acoustic Oscillations in Galaxy Surveys
Burden, Angela; Manera, Marc; Cuesta, Antonio J; Magana, Mariana Vargas; Ho, Shirley
2014-01-01
Reconstructing an estimate of linear Baryon Acoustic Oscillations (BAO) from an evolved galaxy field has become a standard technique in recent analyses. By partially removing non-linear damping caused by bulk motions, the real-space BAO peak in the correlation function is sharpened, and oscillations in the power spectrum are visible to smaller scales. In turn these lead to stronger measurements of the BAO scale. Future surveys are being designed assuming that this improvement has been applied, and this technique is therefore of critical importance for future BAO measurements. A number of reconstruction techniques are available, but the most widely used is a simple algorithm that decorrelates large-scale and small-scale modes approximately removing the bulk-flow displacements by moving the overdensity field (Eisenstein et al. 2007; Padmanabhan, White & Cohn 2009). We consider the practical implementation of this algorithm, looking at the efficiency of reconstruction as a function of the assumptions made fo...
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...
Spin-Directed Momentum Transfers in SIDIS Baryon Production
Sivers, Dennis
2015-01-01
The measurement of transverse single-spin asymmetries for baryon production in the target fragmentation region of semi-inclusive deep-inelastic scattering (SIDIS), can produce important insight into those nonperturbative aspects of QCD directly associated with confinement and with the dynamical breaking of chiral symmetry. We discuss here, interns of spin-directed momentum transfers, the powerful quantum field-theoretical constraints on the spin-orbit dynamics underlying these transverse spin observables. The spin-directed momentum shifts, originating either in the target nucleon or in the QCD jets produced in the deep inelastic scattering process, represent significant quantum entanglement effects connecting information from current fragmentation with observables in target fragmentation.
Measurement of Baryon Electromagnetic Form Factors at BESIII
Morales, Cristina Morales
2016-01-01
The Beijing $e^+e^-$-collider (BEPCII) is a double-ring symmetric collider running at center-of-mass energies between 2.0 and 4.6 GeV. This energy range allows the BESIII-experiment to measure baryon electromagnetic form factors in direct $e^+e^-$-annihilation and in initial state radiation processes. In this paper, results on $e^+e^-\\rightarrow p\\bar{p}$ and $e^+e^-\\rightarrow \\Lambda \\bar{\\Lambda}$ based on data collected by BESIII in 2011 and 2012 are presented. Expectations from the BESIII high luminosity energy scan from 2015 and from radiative return at different center-of-mass energies are also reported.
Observation of the doubly strange b baryon Omegab-.
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Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cuplov, V; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; DeVaughan, K; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Kalk, J M; Karmanov, D; Kasper, P A; Katsanos, I; Kau, D; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Komissarov, E V; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merekov, Y P; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Mitrevski, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Orduna, J; Oshima, N; Osman, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rieger, J; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Rominsky, M; Royon, C; Rozhdestvenski, A; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, E; Strauss, M; Ströhmer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Tamburello, P; Tanasijczuk, A; Taylor, W; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Torchiani, I; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Vertogradova, Y; Verzocchi, M; Vilanova, D; Villeneuve-Seguier, F; Vint, P; Vokac, P; Voutilainen, M; Wagner, R; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Welty-Rieger, L; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Williams, M; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G
2008-12-05
We report the observation of the doubly strange b baryon Omegab- in the decay channel Omegab(-)-->J/psiOmega-, with J/psi-->mu+mu(-) and Omega(-)-->LambdaK(-)-->(ppi-)K-, in pp collisions at sqrt[s]=1.96 TeV. Using approximately 1.3 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider, we observe 17.8+/-4.9(stat)+/-0.8(syst) Omegab- signal events at a mass of 6.165+/-0.010(stat)+/-0.013(syst) GeV. The significance of the observed signal is 5.4sigma, corresponding to a probability of 6.7 x 10(-8) of it arising from a background fluctuation.
Discriminating Majorana Neutrino Textures in the light of Baryon Asymmetry
Borah, Manikanta; Das, Mrinal Kumar
2015-01-01
We study all possible texture zeros in the Majorana neutrino mass matrix which are allowed from neutrino oscillation as well as cosmology data when the charged lepton mass matrix is assumed to take the diagonal form. Considering two different possible values of the lightest neutrino mass giving rise to quasi-degenerate and hierarchical light neutrino mass spectrum respectively, we write down the Majorana CP phases as a function of the Dirac CP phase using the constraints coming from vanishing or equality of elements in a particular texture zero mass matrix. We constrain texture zero mass matrices from the requirement of producing correct baryon asymmetry through the mechanism of leptogenesis. Adopting a type I seesaw framework, we consider the CP violating out of equilibrium decay of the lightest right handed neutrino as the source of lepton asymmetry. Apart from discriminating between the texture zero mass matrices and light neutrino mass hierarchy, we also constrain the Dirac CP phase so that the observed b...
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.
Is the baryon acoustic oscillation peak a cosmological standard ruler?
Roukema, Boudewijn F; Fujii, Hirokazu; Ostrowski, Jan J
2016-01-01
In the standard model of cosmology, the Universe is static in comoving coordinates; expansion occurs homogeneously and is represented by a global scale factor. The baryon acoustic oscillation (BAO) peak location is a statistical tracer that represents, in the standard model, a fixed comoving-length standard ruler. Recent gravitational collapse should modify the metric, rendering the effective scale factor, and thus the BAO standard ruler, spatially inhomogeneous. Using the Sloan Digital Sky Survey, we show to high significance (P < 0.001) that the spatial compression of the BAO peak location increases as the spatial paths' overlap with superclusters increases. Detailed observational and theoretical calibration of this BAO peak location environment dependence will be needed when interpreting the next decade's cosmological surveys.
Baryon masses at nonzero isospin/kaon density
Detmold, William
2013-01-01
We present a lattice QCD calculation of the ground-state energy shifts of various baryons in a medium of pions or kaons at a single value of the quark mass corresponding to a pion mass of m_\\pi~390 MeV and a kaon mass of m_K~540 MeV, and in a spatial volume V (4fm)^3. All systems are created using a canonical formalism in which quark propagators are contracted into correlation functions of fixed isospin/kaon density. We study four different systems, \\Sigma^+(\\pi^+)^n, \\Xi^0(\\pi^+)^n, p(K^+)^n, and n(K^+)^n, for up to n=11 mesons. From the ground-state energy shifts we extract two- and three-body scattering parameters, as well as linear combinations of low-energy constants appearing in tree-level chiral perturbation theory.
Search for Baryonic Decays of \\psi(3770) and \\psi(4040)
Ablikim, M; Albayrak, O; Ambrose, D J; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Becker, J; Bennett, J V; Bertani, M; Bian, J M; Boger, E; Bondarenko, O; Boyko, I; Briere, R A; Bytev, V; Cai, H; Cai, X; akir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, X; Chen, Y B; Cheng, H P; Chu, Y P; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; Ding, W M; Ding, Y; Dong, L Y; Dong, M Y; Du, S X; Fang, J; Fang, S S; Fava, L; Feng, C Q; Friedel, P; Fu, C D; Fu, J L; Gao, Y; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, T; Guo, Y P; Han, Y L; Harris, F A; He, K L; He, M; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Huang, G M; Huang, G S; Huang, J S; Huang, L; Huang, X T; Huang, Y; Huang, Y P; Hussain, T; Ji, C S; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L L; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Jing, F F; Kalantar-Nayestanaki, N; Kavatsyuk, M; Kopf, B; Kornicer, M; Kuehn, W; Lai, W; Lange, J S; Larin, P; Leyhe, M; Li, C H; Li, Cheng; Li, Cui; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, K; Li, Lei; Li, Q J; Li, S L; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, X R; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Liao, X T; Lin, D; Liu, B J; Liu, C L; Liu, C X; Liu, F H; Liu, Fang; Liu, Feng; Liu, H; Liu, H B; Liu, H H; Liu, H M; Liu, H W; Liu, J P; Liu, K; Liu, K Y; Liu, Kai; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lu, G R; Lu, H J; Lu, J G; Lu, Q W; Lu, X R; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Ma, C L; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Moeini, H; Morales, C Morales; Moriya, K; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nicholson, C; Nikolaev, I B; Ning, Z; Olsen, S L; Ouyang, Q; Pacetti, S; Park, J W; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Prencipe, E; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Rong, G; Ruan, X D; Sarantsev, A; Schaefer, B D; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, W M; Song, X Y; Spataro, S; Spruck, B; Sun, D H; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Toth, D; Ullrich, M; Uman, I; Varner, G S; Wang, B Q; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q J; Wang, S G; Wang, X F; Wang, X L; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z Y; Wei, D H; Wei, J B; Weidenkaff, P; Wen, Q G; Wen, S P; Werner, M; Wiedner, U; Wu, L H; Wu, N; Wu, S X; Wu, W; Wu, Z; Xia, L G; Xia, Y X; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, G M; Xu, Q J; Xu, Q N; Xu, X P; Xu, Z R; Xue, F; Xue, Z; Yan, L; Yan, W B; Yan, Y H; Yang, H X; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, H W; Yu, J S; Yu, S P; Yuan, C Z; Yuan, Y; Zafar, A A; Zallo, A; Zang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, LiLi; Zhang, R; Zhang, S H; Zhang, X J; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Z P; Zhang, Z Y; Zhang, Zhenghao; Zhao, G; Zhao, H S; Zhao, J W; Zhao, K X; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, S J; Zhao, T C; Zhao, X H; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zhong, B; Zhou, L; Zhou, X; Zhou, X K; Zhou, X R; Zhu, C; Zhu, K; Zhu, K J; Zhu, S H; Zhu, X L; Zhu, Y C; Zhu, Y M; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H
2013-01-01
By analyzing data samples of 2.9 fb^{-1} collected at \\sqrt s=3.773 GeV, 482 pb^{-1} collected at \\sqrt s=4.009 GeV and 67 pb^{-1} collected at \\sqrt s=3.542, 3.554, 3.561, 3.600 and 3.650 GeV with the BESIII detector at the BEPCII storage ring, we search for \\psi(3770) and \\psi(4040) decay to baryonic final states, including \\Lambda\\bar\\Lambda\\pi^+\\pi^-, \\Lambda \\bar\\Lambda\\pi^0, \\Lambda\\bar\\Lambda\\eta, \\Sigma^+ \\bar\\Sigma^-, \\Sigma^0 \\bar\\Sigma^0, \\Xi^-\\bar\\Xi^+ and \\Xi^0\\bar\\Xi^0 decays. None are observed, and upper limits are set at the 90% confidence level.
Low energy scattering phase shifts for meson-baryon systems
Detmold, William
2015-01-01
In this work, we calculate meson-baryon scattering phase shifts in four channels using lattice QCD methods. From a set of calculations at four volumes, corresponding to spatial sizes of 2, 2.5, 3, and 4 fm, and a pion mass of m_pi ~ 390 MeV, we determine the scattering lengths and effective ranges for these systems at the corresponding quark masses. We also perform the calculation at a lighter quark mass, m_pi ~ 230 MeV, on the largest volume. Using these determinations, along with those in previous work, we perform a chiral extrapolation of the scattering lengths to the physical point after correcting for the effective range contributions using the multi-volume calculations performed at m_pi ~ 390 MeV.
Simultaneous Generation of WIMP Miracle-like Densities of Baryons and Dark Matter
McDonald, John
2011-01-01
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. Dark matter is due to O(100) GeV gauge singlet scalars produced in the annihilation of the O(TeV) coloured scalars which is responsible for the final thermal WIMP-like baryon asymmetry. The requirement of no baryon washout implies that there are two gauge singlet scalars. The low temperature transfer of the asymmetry to conventional baryons can be understood if the long-lived O(TeV) coloured scalars have large hypercharge, |Y| > 4/3. Production of such scalars at the LHC would be a clear signature of the model.
The Baryonic Fraction in Groups of Galaxies from X-Ray Measurements
Henriksen, M J; Henriksen, Mark J.; Mamon, Gary A.
1994-01-01
The recent {\\sl ROSAT \\/} X-ray detections of hot intergalactic gas in three groups of galaxies are reviewed and the resulting baryonic fraction in these groups is reevaluated. We show that the baryonic fraction obtained, assuming hydrostatic equilibrium, should depend, perhaps sensitively, on the radius out to which the X-rays are detected, and the temperature profile of the gas. We find that the NGC 2300 group has a baryonic fraction out to $25'$ of at least 20\\%, thus over five times higher than in the original analysis of Mulchaey \\etal\\ (1993), and also much higher than one would obtain from big-bang nucleosynthesis, but similar to the other two groups as well as rich clusters. With this baryonic fraction, groups would be fair tracers of the distribution of baryons in the Universe if $\\Omega h_{50}^2 = 0.3$. A baryonic fraction that increases with radius is consistent with the X-ray data from all three groups. However, a detailed analysis of the NGC 2300 group shows that the dependence of baryonic fracti...
Semileptonic Decays of Heavy Omega Baryons in a Quark Model
Energy Technology Data Exchange (ETDEWEB)
Muslema Pervin; Winston Roberts; Simon Capstick
2006-03-24
The semileptonic decays of {Omega}{sub c} and {Omega}{sub b} are treated in the framework of a constituent quark model developed in a previous paper on the semileptonic decays of heavy {Lambda} baryons. Analytic results for the form factors for the decays to ground states and a number of excited states are evaluated. For {Omega}{sub b} to {Omega}{sub c} the form factors obtained are shown to satisfy the relations predicted at leading order in the heavy-quark effective theory at the non-recoil point. A modified fit of nonrelativistic and semirelativistic Hamiltonians generates configuration-mixed baryon wave functions from the known masses and the measured {Lambda}{sub c}{sup +} {yields} {Lambda}e{sup +}{nu} rate, with wave functions expanded in both harmonic oscillator and Sturmian bases. Decay rates of {Omega}{sub b} to pairs of ground and excited {Omega}{sub c} states related by heavy-quark symmetry calculated using these configuration-mixed wave functions are in the ratios expected from heavy-quark effective theory, to a good approximation. Our predictions for the semileptonic elastic branching fraction of {Omega}{sub Q} vary minimally within the models we use. We obtain an average value of (84 {+-} 2%) for the fraction of {Omega}{sub c} {yields} {Xi}{sup (*)} decays to ground states, and 91% for the fraction of {Omega}{sub c} {yields} {Omega}{sup (*)} decays to the ground state {Omega}. The elastic fraction of {Omega}{sub b} {yields} {Omega}{sub c} ranges from about 50% calculated with the two harmonic-oscillator models, to about 67% calculated with the two Sturmian models.
Semileptonic Decays of Heavy Lambda Baryons in a Quark Model
Energy Technology Data Exchange (ETDEWEB)
Winston Roberts; Muslema Pervin; Simon Capstick
2005-03-01
The semileptonic decays of {Lambda}{sub c} and {Lambda}{sub b} are treated in the framework of a constituent quark model. Both nonrelativistic and semirelativistic Hamiltonians are used to obtain the baryon wave functions from a fit to the spectra, and the wave functions are expanded in both the harmonic oscillator and Sturmian bases. The latter basis leads to form factors in which the kinematic dependence on q{sup 2} is in the form of multipoles, and the resulting form factors fall faster as a function of q{sup 2} in the available kinematic ranges. As a result, decay rates obtained in the two models using the Sturmian basis are significantly smaller than those obtained using the harmonic oscillator basis. In the case of the {Lambda}{sub c}, decay rates calculated using the Sturmian basis are closer to the experimentally reported rates. However, we find a semileptonic branching fraction for the {Lambda}{sub c} to decay to excited {Lambda}* states of 11% to 19%, in contradiction with what is assumed in available experimental analyses. Our prediction for the {Lambda}{sub b} semileptonic decays is that decays to the ground state {Lambda}{sub c} provide a little less than 70% of the total semileptonic decay rate. For the decays {Lambda}{sub b} {yields} {Lambda}{sub c}, the analytic form factors we obtain satisfy the relations expected from heavy-quark effective theory at the non-recoil point, at leading and next-to-leading orders in the heavy-quark expansion. In addition, some features of the heavy-quark limit are shown to naturally persist as the mass of the heavy quark in the daughter baryon is decreased.
Partially quenched study of strange baryon with Nf = 2 twisted mass fermions
Drach, V; Carbonell, J; Alexandrou, Z L C; Korzec, T; Koutsou, G; Baron, R; Guichon, P; Pène, O; Pallante, E; Reker, S; Urbach, C; Jansen, K
2008-01-01
We present results on the mass of the baryon octet and decuplet using two flavors of light dynamical twisted mass fermions. The strange quark mass is fixed to its physical value from the kaon sector in a partially quenched set up. Calculations are performed for light quark masses corresponding to a pion mass in the range 270-500 MeV and lattice sizes of 2.1 fm and 2.7 fm. We check for cut-off effects and isospin breaking by evaluating the baryon masses at two different lattice spacings. We carry out a chiral extrapolation for the octet baryons and discuss results for the Omega.
Baryon chiral perturbation theory up to next-to-leading order
Bos, J W; Lee, S C; Lin, Y C; Shih, H H; Bos, J W; Chang, D W; Lee, S C; Lin, Y C; Shih, H H
1995-01-01
We examine the general lagrangian for baryon chiral perturbation theory with SU(3) flavor symmetry, up to the next-to-leading order. We consider both the strong and the weak interaction. The inverse of the baryon mass is treated as an additional small expansion parameter, and heavy fermion effective field theory techniques are employed to provide a consistent expansion scheme. A detailed account is given on the restrictions imposed on the lagrangian by the various symmetries. Corrections due to the finite baryon mass are also discussed.
Form Factors and Strong Couplings of Heavy Baryons from QCD Light-Cone Sum Rules
Khodjamirian, A; Mannel, Th; Wang, Y -M
2011-01-01
We derive QCD light-cone sum rules for the hadronic matrix elements of the heavy baryon transitions to nucleon. In the correlation functions the $\\Lambda_c,\\Sigma_c$ and $\\Lambda_b$ -baryons are interpolated by three-quark currents and the nucleon distribution amplitudes are used. To eliminate the contributions of negative parity heavy baryons, we combine the sum rules obtained from different kinematical structures. The results are then less sensitive to the choice of the interpolating current. We predict the $\\Lambda_{b}\\to p$ form factor and calculate the widths of the $\\Lambda_{b}\\to p\\ell\
Present status of the nonstrange and other flavor partners of the exotic Theta+ baryon
Strakovsky, I I; Azimov, Ya I; Polyakov, M V; Workman, R L; Azimov, Ya. I.
2005-01-01
Given the existing empirical information about the exotic Theta+ baryon, we analyze possible properties of its SU(3)F-partners, paying special attention to the nonstrange member of the antidecuplet N*. The modified piN partial-wave analysis presents two candidate masses, 1680 MeV and 1730 MeV. In both cases, the N* should be rather narrow and highly inelastic. Our results suggest several directions for experimental studies that may clarify properties of the antidecuplet baryons, and structure of their mixing with other baryons. Recent experimental evidence from the GRAAL and STAR Collaborations could be interpreted as observations of a candidate for the Theta+ nonstrange partner.
Coupled channel approach to strangeness S = -2 baryon-bayron interactions in Lattice QCD
Sasaki, Kenji; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Ishii, Noriyoshi; Murano, Keiko
2015-01-01
The baryon-baryon interactions with strangeness S = -2 with the flavor SU(3) breaking are calculated for the first time by using the HAL QCD method extended to coupled channel system in lattice QCD. The potential matrices are extracted from the Nambu-Bethe-Salpeter wave functions obtained by the 2+1 flavor gauge configurations of CP-PACS/JLQCD Collaborations with a physical volume of 1.93 fm cubed and with m_pi/m_K = 0.96, 0.90, 0.86. The spatial structure and the quark mass dependence of the potential matrix in the baryon basis and in the SU(3) basis are investigated.
Matrix Theory for Baryons: An Overview of Holographic QCD for Nuclear Physics
Aoki, Sinya; Iizuka, Norihiro
2013-01-01
We provide, for non-experts, a brief overview of holographic QCD and a review of a recent proposal of matrix-description of multi-baryon systems in holographic QCD. Based on the matrix model, we derive the baryon interaction at short distances in multi-flavor holographic QCD. We show that there is a very universal repulsive core of inter-baryon forces for generic number of flavors. This is consistent with a recent lattice QCD analysis for N_f = 2, 3 where repulsive core looks universal. We also provide a comparison of our results with the lattice QCD and the operator product expansion (OPE) analysis.
Directory of Open Access Journals (Sweden)
M. Abu-Shady
2014-01-01
Full Text Available A baryonic chemical potential (μb is included in the linear sigma model at finite temperature. The effective mesonic potential is numerically calculated using the N-midpoint rule. The meson masses are investigated as functions of the temperature (T at fixed value of baryonic chemical potential. The pressure and energy density are investigated as functions of temperature at fi xed value of μb. The obtained results are in good agreement in comparison with other techniques. We conclude that the calculated effective potential successfully predicts the meson properties and thermodynamic properties at finite baryonic chemical potential.
Molecular dynamics simulation for baryon-quark phase transition at finite temperature and density
Akimura, Y; Yoshinaga, N; Chiba, S; Akimura, Yuka; Maruyama, Toshiki; Yoshinaga, Naotaka; Chiba, Satoshi
2005-01-01
We study the baryon-quark phase transition in a molecular dynamics (MD) of quark degrees of freedom at finite temperature and density. The baryon state at low density and temperature, and the deconfined quark state at high density and temperature are reproduced. We investigate the equations of state of matters with different $u$-$d$-$s$ compositions. Then we draw phase diagrams in the temperature-density plane by this simulation. It is found that the baryon-quark transition is sensitive to the quark width.
Baryon Magnetic Moment and Beta Decay Ratio in Colored Quark Cluster Model
Institute of Scientific and Technical Information of China (English)
HU Zheng-Feng; WANG Qing-Wu; DENG Jian-Liao; LEE Xi-Guo; DU Chun-Guang; WANG Yu-Zhu
2008-01-01
Baryon magnetic moments of p, n, ∑+, ∑-, 0, - and the beta decay ratios (GA/GV) of n → p, ∑- → n and 0 →∑+are calculated in a colored quark cluster model. With SU(3) breaking, the model gives a good fit to the experimental values of those baryon magnetic moments and the beta decay ratios. Our results show that the orbital motion has a significant contribution to the spin and magnetic moments of those baryons and the strange component in nucleon is small.
Renormalization of the baryon axial vector current in large-N{sub c}
Energy Technology Data Exchange (ETDEWEB)
Hernandez-Ruiz, Maria de los Angeles [University Aut. de San Luis Potosi, Av. V. Carranza 2405, 78216, San Luis Potosi (Mexico)
2010-07-01
The baryon axial vector current is computed at one-loop order in heavy baryon chiral perturbation theory in the large-N{sub c} limit, where N{sub c} is the number of colors. Loop graphs with octet and decuplet intermediate states cancel to various orders in N{sub c} as a consequence of the large-N{sub c} spin-flavor symmetry of QCD baryons. We present a preliminary study of the convergence of the chiral expansion with 1/N{sub c} corrections in the case of g{sub A} = N{sub c} = 3. (author)
Photon production from quark gluon plasma at ﬁnite baryon density
Indian Academy of Sciences (India)
D Dutta; S V S Sastry; A K Mohanty; K Kumar; R K Choudhury
2003-05-01
The photon yield from a baryon-rich quark gluon plasma (QGP) at SPS energy has been estimated. In the QGP phase, rate of photon production is evaluated up to two-loop level. In the hadron phase, dominant contribution from , , mesons has been considered. The evolution of the plasma has been studied with appropriate equation of state in both QGP and hadron phase for a baryon-rich system. At SPS energy, the total photon yield is found to increase marginally in the presence of baryon density.
Polarized pK{sup -} scattering in Unitary Baryon Chiral Perturbation Theory
Energy Technology Data Exchange (ETDEWEB)
Bouzas, Antonio O. [CINVESTAV-IPN, Departamento de Fisica Aplicada, Carretera Antigua a Progreso Km. 6, Apdo. Postal 73 ' ' Cordemex' ' , Merida, Yucatan (Mexico)
2010-03-15
We study pK{sup -} scattering in the energy range from threshold through the {lambda} (1520) peak in UBChPT, taking into account O(q) vertices from meson-baryon contact interactions and s- and u-channel ground-state baryon exchange, s- and u-channel decuplet- and nonet-baryon exchange and t -channel vector-meson exchange, as well as O(q {sup 2}) flavor-breaking vertices. Detailed fits to data are presented, including a substantial body of differential cross-section data with meson momentum q{sub lab} >300 MeV not considered in previous treatments. (orig.)
Heavy quark symmetry and weak decays of the b baryons in pentaquarks with a c c xAF component
Ali, Ahmed; Ahmed, Ishtiaq; Aslam, M. Jamil; Rehman, Abdur
2016-09-01
Fock space, we present the spectroscopy of the S - and P -wave states in an effective Hamiltonian approach. Some of these pentaquarks can be produced in weak decays of the b -baryons. Combining heavy quark symmetry and the S U (3 )F symmetry results in strikingly simple relations among the decay amplitudes which are presented here.
Heavy quark symmetry and weak decays of the b-baryons in pentaquarks with a c anti c component
Energy Technology Data Exchange (ETDEWEB)
Ali, Ahmed [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ahmed, Ishtiaq; Rehman, Abdur [Quaid-i-Azam Univ., Islamabad (Pakistan). National Centre for Physics; Aslam, M. Jamil [Quaid-i-Azam Univ., Islamabad (Pakistan). Physics Dept.
2016-06-15
341 MeV, we estimate the mass of the lower pentaquark J{sup P}=3/2{sup -} state to be about 4110 MeV and suggest to reanalyze the LHCb data to search for this third state. Extending these considerations to the pentaquark states having a c anti c pair and three light quarks (u,d,s) in their Fock space, we present the spectroscopy of the S- and P-wave states in an effective Hamiltonian approach. Some of these pentaquarks can be produced in weak decays of the b-baryons. Combining heavy quark symmetry and the SU(3){sub F} symmetry results in strikingly simple relations among the decay amplitudes which are presented here.
Aulakh, Charanjit S; Khosa, Charanjit K
2014-01-01
Superheavy threshold corrections to the matching condition between matter Yukawa couplings of the effective Minimal Supersymmetric Standard Model (MSSM) and the New Minimal Supersymmetric (SO(10)) GUT(NMSGUT) provide a novel and generic mechanism for reducing the long standing and generically problematic operator dimension 5 Baryon decay rates. In suitable regions of the parameter space strong wave function renormalization of the effective MSSM Higgs doublets due to the large number of heavy fields can take the Wave function renormalization of the MSSM Higgs field close to the dissolution value ($Z_{H,\\overline{H}}=0$). Rescaling to canonical kinetic terms lowers the SO(10) Yukawas required to match the MSSM fermion data. Since the same Yukawas determine the dimension 5 B violation operator coefficients, the associated rates can be suppressed to levels compatible with current limits. Including these threshold effects also relaxes the constraint $ y_b-y_\\tau\\simeq y_s-y_\\mu$ operative between $\\textbf{10} -\\te...
Energy Technology Data Exchange (ETDEWEB)
Aulakh, Charanjit S., E-mail: aulakh@pu.ac.in; Garg, Ila; Khosa, Charanjit K.
2014-05-15
Superheavy threshold corrections to the matching condition between matter Yukawa couplings of the effective Minimal Supersymmetric Standard Model (MSSM) and the New Minimal Supersymmetric (SO(10)) GUT (NMSGUT) provide a novel and generic mechanism for reducing the long standing and generically problematic operator dimension 5 baryon decay rates. In suitable regions of the parameter space strong wave function renormalization of the effective MSSM Higgs doublets due to the large number of heavy fields can take the wave function renormalization of the MSSM Higgs field close to the dissolution value (Z{sub H,H{sup ¯}}=0). Rescaling to canonical kinetic terms lowers the SO(10) Yukawas required to match the MSSM fermion data. Since the same Yukawas determine the dimension 5 B violation operator coefficients, the associated rates can be suppressed to levels compatible with current limits. Including these threshold effects also relaxes the constraint y{sub b}−y{sub τ}≃y{sub s}−y{sub μ} operative between 10–120-plet generated tree level MSSM matter fermion Yukawas y{sub f}. We exhibit accurate fits of the MSSM fermion mass-mixing data in terms of NMSGUT superpotential couplings and 5 independent soft Susy breaking parameters specified at 10{sup 16.25} GeV with the claimed suppression of baryon decay rates. As before, our s-spectra are of the mini split supersymmetry type with large |A{sub 0}|,μ,m{sub H,H{sup ¯}}>100 TeV, light gauginos and normal s-hierarchy. Large A{sub 0},μ and soft masses allow significant deviation from the canonical GUT gaugino mass ratios and ensure vacuum safety. Even without optimization, prominent candidates for BSM discovery such as the muon magnetic anomaly, b→sγ and leptogenesis CP violation emerge in the preferred ball park.
Aulakh, Charanjit S.; Garg, Ila; Khosa, Charanjit K.
2014-05-01
Superheavy threshold corrections to the matching condition between matter Yukawa couplings of the effective Minimal Supersymmetric Standard Model (MSSM) and the New Minimal Supersymmetric (SO(10)) GUT (NMSGUT) provide a novel and generic mechanism for reducing the long standing and generically problematic operator dimension 5 baryon decay rates. In suitable regions of the parameter space strong wave function renormalization of the effective MSSM Higgs doublets due to the large number of heavy fields can take the wave function renormalization of the MSSM Higgs field close to the dissolution value (ZH,Hbar=0). Rescaling to canonical kinetic terms lowers the SO(10) Yukawas required to match the MSSM fermion data. Since the same Yukawas determine the dimension 5 B violation operator coefficients, the associated rates can be suppressed to levels compatible with current limits. Including these threshold effects also relaxes the constraint yb-yτ≃ys-yμ operative between 10-120-plet generated tree level MSSM matter fermion Yukawas yf. We exhibit accurate fits of the MSSM fermion mass-mixing data in terms of NMSGUT superpotential couplings and 5 independent soft Susy breaking parameters specified at 1016.25 GeV with the claimed suppression of baryon decay rates. As before, our s-spectra are of the mini split supersymmetry type with large |A0|,μ,mH,Hbar>100 TeV, light gauginos and normal s-hierarchy. Large A0,μ and soft masses allow significant deviation from the canonical GUT gaugino mass ratios and ensure vacuum safety. Even without optimization, prominent candidates for BSM discovery such as the muon magnetic anomaly, b→sγ and leptogenesis CP violation emerge in the preferred ball park.
Ross, Ashley J; Chuang, Chia-Hsun; Pellejero-Ibanez, Marcos; Seo, Hee-Jong; Vargas-Magana, Mariana; Cuesta, Antonio J; Percival, Will J; Burden, Angela; Sanchez, Ariel G; Grieb, Jan Niklas; Reid, Beth; Brownstein, Joel R; Dawson, Kyle S; Eisenstein, Daniel J; Ho, Shirley; Kitaura, Francisco-Shu; Nichol, Robert C; Olmstead, Matthew D; Prada, Francisco; Rodriguez-Torres, Sergio A; Saito, Shun; Salazar-Albornoz, Salvador; Schneider, Donald P; Thomas, Daniel; Tinker, Jeremy; Tojeiro, Rita; Wang, Yuting; White, Martin; Zhao, Gong-bo
2016-01-01
We present baryon acoustic oscillation (BAO) scale measurements determined from the clustering of 1.2 million massive galaxies with redshifts 0.2 < z < 0.75 distributed over 9300 square degrees, as quantified by their redshift-space correlation function. In order to facilitate these measurements, we define, describe, and motivate the selection function for galaxies in the final data release (DR12) of the SDSS III Baryon Oscillation Spectroscopic Survey (BOSS). This includes the observational footprint, masks for image quality and Galactic extinction, and weights to account for density relationships intrinsic to the imaging and spectroscopic portions of the survey. We simulate the observed systematic trends in mock galaxy samples and demonstrate that they impart no bias on baryon acoustic oscillation (BAO) scale measurements and have a minor impact on the recovered statistical uncertainty. We measure transverse and radial BAO distance measurements in 0.2 < z < 0.5, 0.5 < z < 0.75, and (overla...