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Author Valdes-Cortez, C.; Mansour, I.; Rivard, M.J.; Ballester, F.; Mainegra-Hing, E.; Thomson, R.M.; Vijande, J. url  doi
openurl 
  Title A study of Type B uncertainties associated with the photoelectric effect in low-energy Monte Carlo simulations Type Journal Article
  Year 2021 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.  
  Volume 66 Issue 10 Pages 105014 - 14pp  
  Keywords Monte Carlo simulations; brachytherapy; low energy physics; photoelectric effect  
  Abstract Purpose. To estimate Type B uncertainties in absorbed-dose calculations arising from the different implementations in current state-of-the-art Monte Carlo (MC) codes of low-energy photon cross-sections (<200 keV). Methods. MC simulations are carried out using three codes widely used in the low-energy domain: PENELOPE-2018, EGSnrc, and MCNP. Three dosimetry-relevant quantities are considered: mass energy-absorption coefficients for water, air, graphite, and their respective ratios; absorbed dose; and photon-fluence spectra. The absorbed dose and the photon-fluence spectra are scored in a spherical water phantom of 15 cm radius. Benchmark simulations using similar cross-sections have been performed. The differences observed between these quantities when different cross-sections are considered are taken to be a good estimator for the corresponding Type B uncertainties. Results. A conservative Type B uncertainty for the absorbed dose (k = 2) of 1.2%-1.7% (<50 keV), 0.6%-1.2% (50-100 keV), and 0.3% (100-200 keV) is estimated. The photon-fluence spectrum does not present clinically relevant differences that merit considering additional Type B uncertainties except for energies below 25 keV, where a Type B uncertainty of 0.5% is obtained. Below 30 keV, mass energy-absorption coefficients show Type B uncertainties (k = 2) of about 1.5% (water and air), and 2% (graphite), diminishing in all materials for larger energies and reaching values about 1% (40-50 keV) and 0.5% (50-75 keV). With respect to their ratios, the only significant Type B uncertainties are observed in the case of the water-to-graphite ratio for energies below 30 keV, being about 0.7% (k = 2). Conclusions. In contrast with the intermediate (about 500 keV) or high (about 1 MeV) energy domains, Type B uncertainties due to the different cross-sections implementation cannot be considered subdominant with respect to Type A uncertainties or even to other sources of Type B uncertainties (tally volume averaging, manufacturing tolerances, etc). Therefore, the values reported here should be accommodated within the uncertainty budget in low-energy photon dosimetry studies.  
  Address [Valdes-Cortez, Christian; Ballester, Facundo; Vijande, Javier] Univ Valencia UV, Dept Fis Atom Mol & Nucl, Burjassot, Spain, Email: javier.vijande@uv.es  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9155 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000655291500001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4847  
Permanent link to this record
 

 
Author Richard, J.M.; Valcarce, A.; Vijande, J. url  doi
openurl 
  Title Effect of relativistic kinematics on the stability of multiquarks Type Journal Article
  Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 103 Issue 5 Pages 054020 - 8pp  
  Keywords  
  Abstract We discuss whether the bound nature of multiquark states in quark models could benefit from relativistic effects on the kinetic energy operator. For mesons and baryons, relativistic corrections to the kinetic energy lead to lower energies, and thus call for a retuning of the parameters of the model. For multiquark states, as well as their respective thresholds, a comparison is made of the results obtained with nonrelativistic and relativistic kinetic energy. It is found that the binding energy is lower in the relativistic case. In particular, QQ (q) over bar(q) over bar tetraquarks with double heavy flavor become stable for a larger ratio of the heavy to light quark masses; the all-heavy tetraquarks QQ (Q) over bar(Q) over bar that are not stable in standard nonrelativistic quark models remain unstable when a relativistic form of kinetic energy is adopted.  
  Address [Richard, Jean-Marc] Univ Lyon, Inst Phys Infinis Lyon 2, IN2P3 CNRS UCBL, 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:000648531300004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4838  
Permanent link to this record
 

 
Author Richard, J.M.; Valcarce, A.; Vijande, J. url  doi
openurl 
  Title Very Heavy Flavored Dibaryons Type Journal Article
  Year 2020 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 124 Issue 21 Pages 212001 - 4pp  
  Keywords  
  Abstract We explore the possibility of very heavy dibaryons with three charm quarks and three beauty quarks, bbbccc, using a constituent model which should lead to the correct solution in the limit of hadrons made of heavy quarks. The six-body problem is treated rigorously, in particular taking into account the orbital, color, and spin mixed-symmetry components of the wave function. Unlike a recent claim based on lattice QCD, no bound state is found below the lowest dissociation threshold.  
  Address [Richard, Jean-Marc] Univ Lyon, Inst Phys Infinis Lyon 2, IN2P3, CNRS,UCBL, 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 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000535679100015 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4408  
Permanent link to this record
 

 
Author Garcilazo, H.; Valcarce, A.; Vijande, J. url  doi
openurl 
  Title Neutral baryonic systems with strangeness Type Journal Article
  Year 2020 Publication International Journal of Modern Physics E Abbreviated Journal Int. J. Mod. Phys. E  
  Volume 29 Issue 1 Pages 1930009 - 22pp  
  Keywords Few-body systems; baryon-baryon interaction; hypernuclei  
  Abstract We review the status as regards to the existence of three- and four-body bound states made of neutrons and Lambda hyperons. For interesting cases, the coupling to neutral baryonic systems made of charged particles of different strangeness has been addressed. There are strong arguments showing that the Lambda nn system has no bound states. Lambda Lambda nn strong stable states are not favored by our current knowledge of the strangeness -1 and -2 baryon-baryon interactions. However, a possible Xi(-) t quasibound state decaying to Lambda Lambda nn might exist in nature. Similarly, there is a broad agreement about the nonexistence of Lambda Lambda n bound states. However, the coupling to Xi NN states opens the door to a resonance above the Lambda Lambda n threshold.  
  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 World Scientific Publ Co Pte Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0218-3013 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000527883500003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4381  
Permanent link to this record
 

 
Author Garcilazo, H.; Valcarce, A.; Vijande, J. url  doi
openurl 
  Title Xi(-)t quasibound state instead of Lambda Lambda nn bound state Type Journal Article
  Year 2020 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C  
  Volume 44 Issue 2 Pages 024102 - 7pp  
  Keywords baryon-baryon interactions; few-body systems; Faddeev equations  
  Abstract The coupled Lambda Lambda nn – Xi-pnn system was studied to investigate whether the inclusion of channel coupling is able to bind the Lambda Lambda nn system. We use a separable potential three-body model of the coupled Lambda Lambda nn – Xi-pnn system and a variational four-body calculation with realistic interactions. Our results exclude the possibility of a bound state by a large margin. Instead, we found a Xi(-)t quasibound state above the Lambda Lambda nn threshold.  
  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 Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1674-1137 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000509960900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4267  
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