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Author Fontoura, C.E.; Krein, G.; Valcarce, A.; Vijande, J.
Title (up) Production of exotic tetraquarks QQ(q)over-bar (q)over-bar in heavy-ion collisions at the LHC Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 9 Pages 094037 - 8pp
Keywords
Abstract We investigate the production of exotic tetraquarks, QQ (q) over bar (q) over bar T-QQ (Q = c or b and q = u or d), in relativistic heavy-ion collisions using the quark coalescence model. The T-QQ yield is given by the overlap of the density matrix of the constituents in the emission source with the Wigner function of the produced tetraquark. The tetraquark wave function is obtained from exact solutions of the four-body problem using realistic constituent models. The production yields are typically one order of magnitude smaller than previous estimations based on simplified wave functions for the tetraquarks. We also evaluate the consequences of the partial restoration of chiral symmetry at the hadronization temperature on the coalescence probability. Such effects, in addition to increasing the stability of the tetraquarks, lead to an enhancement of the production yields, pointing towards an excellent discovery potential in forthcoming experiments. We discuss further consequences of our findings for the search of exotic tetraquarks in central Pb + Pb collisions at the LHC.
Address [Fontoura, C. E.] DCTA, Inst Tecnol Aeronaut, BR-12228900 Sao Jose Dos Campos, SP, Brazil, Email: ce.fontoura@unesp.br;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000469331100006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4030
Permanent link to this record
 
 
Author Vijande, J.; Valcarce, A.; Richard, J.M.; Sorba, P.
Title (up) Search for doubly-heavy dibaryons in a quark model Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 94 Issue 3 Pages 034038 - 6pp
Keywords
Abstract We study the stability of hexaquark systems containing two heavy quarks and four light quarks within a simple quark model. No bound or metastable state is found. The reason stems from a delicate interplay between chromoelectric and chromomagnetic effects. Our calculation also provides information about anticharmed pentaquarks that are seemingly unbound in simple quark models.
Address [Vijande, J.] UV, Dept Fis Atom Mol & Nucl, E-46100 Valencia, Spain, Email: javier.vijande@uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000381893500004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2778
Permanent link to this record
 
 
Author Hernandez, E.; Vijande, J.; Valcarce, A.; Richard, J.M.
Title (up) Spectroscopy, lifetime and decay modes of the T-bb(-) tetraquark Type Journal Article
Year 2020 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 800 Issue Pages 135073 - 9pp
Keywords
Abstract We present the first full-fledged study of the flavor-exotic isoscalar T-bb(-) equivalent to bb (u) over bar(d) over bar tetraquark with spin and parity J(P) = 1(+). We report accurate solutions of the four-body problem in a quark model, characterizing the structure of the state as a function of the ratio M-Q/m(q) of the heavy to light quark masses. For such a standard constituent model, T-bb(-) lies approximately 150 MeV below the strong decay threshold B- (B) over bar*(0) and 105 MeV below the electromagnetic decay threshold B- (B) over bar (0)gamma. We evaluate the lifetime of T-bb(-), identifying the promising decay modes where the tetraquark might be looked for in future experiments. Its total decay width is Gamma approximate to 87 x 10(-15) GeV and therefore its lifetime tau approximate to 7.6 ps. The promising final states are B*(-) D*(+) l (v) over bar (l) and (B) over bar*(0) l (v) over bar (l) among the semileptonic decays, and B*(-) D*(+) D-s*(-), (B) over bar*(0) D*(0) D-s*(-), and B*(-) D*(+) rho(-) among the nonleptonic ones. The semileptonic decay to the isoscalar J(P) = 0(+) tetraquark T-bc(0) is also relevant but it is not found to be dominant. There is a broad consensus about the existence of this tetraquark, and its detection will validate our understanding of the low-energy realizations of Quantum Chromodynamics (QCD) in the multiquark sector.
Address [Hernandez, E.; Valcarce, A.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: gajatee@usal.es;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000503832500055 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4240
Permanent link to this record
 
 
Author Valcarce, A.; Vijande, J.; Richard, J.M.; Garcilazo, H.
Title (up) Stability of Heavy Tetraquarks Type Journal Article
Year 2018 Publication Few-Body Systems Abbreviated Journal Few-Body Syst.
Volume 59 Issue 2 Pages 9 - 7pp
Keywords
Abstract We discuss the stability of tetraquark systems with two different masses. After some reminders about the stability of very asymmetric QQ (q) over bar(q) over bar tetraquarks, we demonstrate that in the all-heavy limit q -> Q, the system becomes unstable for standard color-additive models. We also analyze the consequences of symmetry breaking for Qq (Q) over bar(q) over bar configurations: we find a kind of metastability between the lowest threshold Q (Q) over bar + q (q) over bar and the highest one, Q (q) over bar + (Q) over barq, and we calculate the width of the resonance. Our results are consistent with the experimental observation of narrow hadrons lying well above their lowest decay threshold.
Address [Valcarce, A.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: valcarce@usal.es;
Corporate Author Thesis
Publisher Springer Wien Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0177-7963 ISBN Medium
Area Expedition Conference
Notes WOS:000427011200005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3574
Permanent link to this record
 
 
Author Vijande, J.; Valcarce, A.; Richard, J.M.
Title (up) Stability of hexaquarks in the string limit of confinement Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 85 Issue 1 Pages 014019 - 6pp
Keywords
Abstract The stability of systems containing six quarks or antiquarks is studied within a simple string model inspired by the strong-coupling regime of quantum chromodynamics and used previously for tetraquarks and pentaquarks. We discuss both six-quark (q(6)) and three-quark-three-antiquark (q(3)($) over bar (3)) states. The quarks are assumed to be distinguishable and thus not submitted to antisymmetrization. It is found that the ground state of (q(6)) is stable against dissociation into two isolated baryons. For the case of (q(3)($) over bar (3)), our results indicate the existence of a bound state very close to the threshold. The investigations are extended to (q(3)Q(3)) and (Q(3) ($) over bar (3)) systems with two different constituent masses, and their stability is discussed as a function of the mass ratio.
Address [Vijande, J.] Univ Valencia, Dept Fis Atom Mol & Nucl, Valencia, Spain, Email: javier.vijande@uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000299293600006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 883
Permanent link to this record
 
 
Author Garcilazo, H.; Valcarce, A.; Vijande, J.
Title (up) Stable bound states of N's, Lambda's and Xi's Type Journal Article
Year 2017 Publication Revista Mexicana de Fisica Abbreviated Journal Rev. Mex. Fis.
Volume 63 Issue 5 Pages 411-422
Keywords Baryon-Baryon interactions; Faddeev equations; variational approaches
Abstract We review our recent work about the stability of strange few-body systems containing N's, Lambda's, and Xi's. We make use of local central Yukawa-type Malfliet-Tjon interactions reproducing the low-energy parameters and phase shifts of the nucleon-nucleon system and the latest updates of the hyperon-nucleon and hyperon-hyperon ESCO8c Nijmegen potentials. We solve the three-and four-body bound-state problems by means of Faddeev equations and a generalized Gaussian variational method, respectively. The hypertriton, Lambda np(I)J(P) = (1/2)1/2(+), is bound by 144 keV; the recently discussed Lambda nn (I)J(P) = (1/2)1/2(+) system is unbound, as well as the Lambda Lambda nn (I)J(P) = (1)0(+) system, being just above threshold. Our results indicate that the Xi NN, Xi Xi N and Xi Xi NN systems with maximal isospin might be bound.
Address [Garcilazo, H.] Inst Politecn Nacl, Escuela Super Fis & Matemat, Edificio 9, Mexico City 07738, DF, Mexico, Email: humberto@esfm.ipn.mx;
Corporate Author Thesis
Publisher Soc Mexicana Fisica Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-001x ISBN Medium
Area Expedition Conference
Notes WOS:000410015700003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3291
Permanent link to this record
 
 
Author Richard, J.M.; Valcarce, A.; Vijande, J.
Title (up) Stable heavy pentaquarks in constituent models Type Journal Article
Year 2017 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 774 Issue Pages 710-714
Keywords
Abstract It is shown that standard constituent quark models produce ((c)over-barcqqq) hidden-charm pentaquarks, where c denotes the charmed quark and q a light quark, which lie below the lowest threshold for spontaneous dissociation and thus are stable in the limit where the internal (c)over-barc annihilation is neglected. The binding is a cooperative effect of the chromoelectric and chromomagnetic components of the interaction, and it disappears in the static limit with a pure chromoelectric potential. Their wave function contains color sextet and color octet configurations for the subsystems and can hardly be reduced to a molecular state made of two interacting hadrons. These pentaquark states could be searched for in the experiments having discovered or confirmed the hidden-charm meson and baryon resonances.
Address [Richard, J. -M.] Univ Lyon, Inst Phys Nucl Lyon, IN2P3, CNRS UCBL, 4 Rue Enrico Fermi, F-69622 Villeurbanne, France, Email: j-m.richard@ipnl.in2p3.fr;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000414973200093 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3408
Permanent link to this record
 
 
Author Richard, J.M.; Valcarce, A.; Vijande, J.
Title (up) String dynamics and metastability of all-heavy tetraquarks Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 95 Issue 5 Pages 054019 - 7pp
Keywords
Abstract Multiquark states have been advocated to explain recent experimental data in the heavy-light sector, and there are already speculations about multiquarks containing only heavy quarks and antiquarks. With a rigorous treatment of the four-body problem in current quark models, full-charm (cc (c) over bar(c) over bar) and full-beauty(bb (b) over bar(b) over bar) tetraquarks are found to be unbound. Thus their stability should rely on more subtle effects that are not included in the simple picture of constituent quarks. The case of (bc (b) over bar(c) over bar) might be more favorable if the naive color-additive model of confinement is replaced by a string-inspired interaction.
Address [Richard, Jean-Marc] Univ Lyon, UCBL, Inst Phys Nucl Lyon, IN2P3,CNRS, 4 Rue Enrico Fermi, F-69622 Villeurbanne, France, Email: j-m.richard@ipnl.in2p3.fr;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000399144700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3047
Permanent link to this record
 
 
Author Carames, T.F.; Valcarce, A.; Vijande, J.
Title (up) Too many X's, Y's and Z's? Type Journal Article
Year 2012 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 709 Issue 4-5 Pages 358-361
Keywords
Abstract A large number of new states have been reported during the last few years in charmonium spectroscopy above the charmed meson production threshold. They have been called X's, Y's, and Z's. We reflect on the influence of thresholds on heavy meson spectroscopy comparing different flavor sectors and quantum numbers. The validity of a quark-model picture above open-flavor thresholds would severely restrict the number of channels that may lodge meson-meson molecules.
Address [Carames, T. F.; Valcarce, A.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: valcarce@usal.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000302454700005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 978
Permanent link to this record
 
 
Author Vijande, J.; Valcarce, A.
Title (up) Unraveling the pattern of the XYZ mesons Type Journal Article
Year 2014 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 736 Issue Pages 325-328
Keywords
Abstract We present a plausible mechanism for the origin of the XYZ mesons in the heavy meson spectra within a standard quark-model picture. We discuss the conditions required for the existence of four-quark bound states or resonances contributing to the heavy meson spectra, being either compact or molecular. We concentrate on charmonium and bottomonium spectra, where several new states, difficult to understand as simple quark-antiquark pairs, have been reported by different experimental collaborations. The pivotal role played by entangled meson-meson thresholds is emphasized.
Address [Vijande, J.] Univ Valencia, Dept Fis Atom Mol & Nucl, Valencia, Spain
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000341487800048 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1939
Permanent link to this record