Records |
Author |
Magas, V.K.; Yamagata-Sekihara, J.; Hirenzaki, S.; Oset, E.; Ramos, A. |
Title |
Proton emission off nuclei induced by kaons in flight |
Type |
Journal Article |
Year |
2010 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
81 |
Issue |
2 |
Pages |
024609 - 10pp |
Keywords |
|
Abstract |
We study the (K-, p) reaction on nuclei with a 1 GeV/c momentum kaon beam, paying special attention to the region of emitted protons having kinetic energy above 600 MeV, which was used to claim a deeply attractive kaon nucleus optical potential. Our model describes the nuclear reaction in the framework of a local density approach and the calculations are performed following two different procedures: one is based on a many-body method using the Lindhard function and the other is based on a Monte Carlo simulation. The simulation method offers flexibility to account for processes other than kaon quasielastic scattering, such as K- absorption by one and two nucleons, producing hyperons, and allows consideration of final-state interactions of the K-, the p, and all other primary and secondary particles on their way out of the nucleus, as well as the weak decay of the produced hyperons into pi N. We find a limited sensitivity of the cross section to the strength of the kaon optical potential. We also show a serious drawback in the experimental setup-the requirement for having, together with the energetic proton, at least one charged particle detected in the decay counter surrounding the target-as we find that the shape of the original cross section is appreciably distorted, to the point of invalidating the claims made in the experimental paper on the strength of the kaon nucleus optical. |
Address |
[Magas, V. K.; Ramos, A.] Univ Barcelona, Dept Estructura & Constituents Mat, E-08028 Barcelona, Spain, Email: vladimir@ecm.ub.es |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0556-2813 |
ISBN |
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Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
ISI:000278341300014 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
432 |
Permanent link to this record |
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Author |
Tolos, L.; Cabrera, D.; Garcia-Recio, C.; Molina, R.; Nieves, J.; Oset, E.; Ramos, A.; Romanets, O.; Salcedo, L.L. |
Title |
Strangeness and charm in nuclear matter |
Type |
Journal Article |
Year |
2013 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Nuclear Physics A |
Abbreviated Journal |
Nucl. Phys. A |
Volume |
914 |
Issue |
|
Pages |
461-471 |
Keywords |
Strange mesons; Transparency ratio; Dynamically-generated baryon resonances; Open charm in matter; D-mesic nuclei |
Abstract |
The properties of strange (K, (K) over bar and (K) over bar*) and open-charm (D, (D) over bar and D*) mesons in dense matter are studied using a unitary approach in coupled channels for meson-baryon scattering. In the strangeness sector, the interaction with nucleons always comes through vector-meson exchange, which is evaluated by chiral and hidden gauge Lagrangians. For the interaction of charmed mesons with nucleons we extend the SU(3) Weinberg-Tomozawa Lagrangian to incorporate spin-flavor symmetry and implement a suitable flavor symmetry breaking. The in-medium solution for the scattering amplitude accounts for Pauli blocking effects and meson self-energies. On one hand, we obtain the K, (K) over bar and (K) over bar* spectral functions in the nuclear medium and study their behaviour at finite density, temperature and momentum. We also make an estimate of the transparency ratio of the gamma A -> K+ K*(-) A' reaction, which we propose as a tool to detect in-medium modifications of the (K) over bar* meson. On the other hand, in the charm sector, several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2(+) and 3/2(+) baryons. The properties of these states in matter are analyzed and their influence on the open-charm meson spectral functions is studied. We finally discuss the possible formation of D-mesic nuclei at FAIR energies. |
Address |
[Tolos, Laura] Fac Ciencies, Inst Ciencias Espacio IEEC CSIC, E-08193 Bellaterra, Barcelona, Spain, Email: tolos@ice.csic.es |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0375-9474 |
ISBN |
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Medium |
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Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000324847700066 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1598 |
Permanent link to this record |
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Author |
Oset, E.; Chen, H.X.; Feijoo, A.; Geng, L.S.; Liang, W.H.; Li, D.M.; Lu, J.X.; Magas, V.K.; Nieves, J.; Ramos, A.; Roca, L.; Wang, E.; Xie, J.J. |
Title |
Study of reactions disclosing hidden charm pentaquarks with or without strangeness |
Type |
Journal Article |
Year |
2016 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Nuclear Physics A |
Abbreviated Journal |
Nucl. Phys. A |
Volume |
954 |
Issue |
|
Pages |
371-392 |
Keywords |
Pentaquark reactions; Molecular states with hidden charm |
Abstract |
We present results for five reactions, Lambda(b) -> J/psi K(-)p, Lambda(b) -> J/psi eta Lambda, Lambda(b) -> J/psi pi(-)p, Lambda(b) -> J/psi K-0 Lambda and Xi(-)(b) -> J/psi K-Lambda, where combining information from the meson baryon interaction, using the chiral unitary approach, and predictions made for molecular states of hidden charm, with or without strangeness, we can evaluate invariant mass distributions for the light meson baryon states, and for those of J/psi p or J/psi Lambda. We show that with the present available information, in all of these reactions one finds peaks where the pentaquark states show up. In the Lambda(b) -> J/psi K(-)p, and Lambda(b) -> J/psi pi(-)p reactions we show that the results obtained from our study are compatible with present experimental observations. |
Address |
[Oset, Eulogio] Univ Valencia, Ctr Mixto, CSIC, Inst Invest Paterna,Dept Fis Teor, Aptdo 22085, E-46071 Valencia, Spain, Email: oset@ific.uv.es |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
|
Language |
English |
Summary Language |
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Original Title |
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Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0375-9474 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000381331200025 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2791 |
Permanent link to this record |
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Author |
Martinez Torres, A.; Oset, E.; Prelovsek, S.; Ramos, A. |
Title |
Reanalysis of lattice QCD spectra leading to the Ds0*(2317) and Ds1*(2460) |
Type |
Journal Article |
Year |
2015 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
05 |
Issue |
5 |
Pages |
153 - 22pp |
Keywords |
Lattice QCD; Phenomenological Models; QCD |
Abstract |
We perform a reanalysis of the energy levels obtained in a recent lattice QCD simulation, from where the existence of bound states of KD and KD* are induced and identified with the narrow D-s0*(2317) and D-s1*(2460) resonances. The reanalysis is done in terms of an auxiliary potential, employing a single-channel basis KD(*()), and a two-channel basis KD(*()), eta D-s(()*()). By means of an extended Luscher method we determine poles of the continuum t-matrix, bound by about 40 MeV with respect to the KD and KD* thresholds, which we identify with the D-s0*(2317) and D-s1*(2460) resonances. Using a sum rule that reformulates Weinberg compositeness condition we can determine that the state D-s0*(2317) contains a KD component in an amount of about 70%, while the state D-s1*(2460) contains a similar amount of KD*. We argue that the present lattice simulation results do not still allow us to determine which are the missing channels in the bound state wave functions and we discuss the necessary information that can lead to answer this question. |
Address |
[Martinez Torres, A.] Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, SP, Brazil, Email: amartine@if.usp.br; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1029-8479 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000355346500002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2258 |
Permanent link to this record |
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Author |
Oset, E.; Ramos, A.; Garzon, E.J.; Molina, R.; Tolos, L.; Xiao, C.W.; Wu, J.J.; Zou, B.S. |
Title |
Interaction of vector mesons with baryons and nuclei |
Type |
Journal Article |
Year |
2012 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
International Journal of Modern Physics E |
Abbreviated Journal |
Int. J. Mod. Phys. E |
Volume |
21 |
Issue |
11 |
Pages |
1230011 - 18pp |
Keywords |
Vector-baryon interaction; vectors in medium; J/psi suppression in nuclei |
Abstract |
After some short introductory remarks on particular issues on the vector mesons in nuclei, in this paper, we present a short review of recent developments concerning the interaction of vector mesons with baryons and with nuclei from a modern perspective using the local hidden gauge formalism for the interaction of vector mesons. We present results for the vector-baryon interaction and in particular for the resonances which appear as composite states, dynamically generated from the interaction of vector mesons with baryons, taking also the mixing of these states with pseudoscalars and baryons into account. We then venture into the charm sector, reporting on hidden charm baryon states around 4400 MeV, generated from the interaction of vector mesons and baryons with charm, which have a strong repercussion on the properties of the J/Psi N interaction. We also address the interaction of K* with nuclei and make suggestions to measure the predicted huge width in the medium by means of transparency ratio. The formalism is extended to study the phenomenon of J/psi suppression in nuclei via J/psi photo-production reactions. |
Address |
[Oset, E.; Garzon, E. J.; Xiao, C. W.] Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor, Valencia 46071, Spain, Email: oset@ific.uv.es |
Corporate Author |
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Thesis |
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Publisher |
World Scientific Publ Co Pte Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0218-3013 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000310855800002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1204 |
Permanent link to this record |
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|
Author |
Oset, E.; Albaladejo, M.; Xie, J.J.; Ramos, A. |
Title |
Recent developments on hadron interaction and dynamically generated resonances |
Type |
Journal Article |
Year |
2014 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
International Journal of Modern Physics E |
Abbreviated Journal |
Int. J. Mod. Phys. E |
Volume |
23 |
Issue |
7 |
Pages |
1461008 - 8pp |
Keywords |
Hadron interaction; dynamically generated resonances |
Abstract |
In this talk I report on the recent developments in the subject of dynamically generated resonances. In particular I discuss the gamma p -> K-0 Sigma+ and gamma n -> K-0 Sigma(0) reactions, with a peculiar behavior around the K*(0)Lambda threshold, due to a 1/2(-) resonance around 2035 MeV. Similarly, I discuss a BES experiment, J/psi -> eta K*(0) (K) over bar*(0) decay, which provides evidence for a new h(1) resonance around 1830 MeV that was predicted from the vector-vector interaction. A short discussion is then made about recent advances in the charm and beauty sectors. |
Address |
[Oset, E.; Albaladejo, M.; Ramos, A.] Univ Valencia, Inst Invest Paterna, Ctr Mixto, Dept Fis Teor,CSIC, Valencia 46071, Spain, Email: oset@ific.uv.es |
Corporate Author |
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Thesis |
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Publisher |
World Scientific Publ Co Pte Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0218-3013 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000341934000009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1946 |
Permanent link to this record |
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Author |
Martinez Torres, A.; Prelovsek, S.; Oset, E.; Ramos, A. |
Title |
Effective Field Theories in a Finite Volume |
Type |
Journal Article |
Year |
2018 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Few-Body Systems |
Abbreviated Journal |
Few-Body Syst. |
Volume |
59 |
Issue |
6 |
Pages |
139 - 5pp |
Keywords |
|
Abstract |
In this talk I present the formalism we have used to analyze Lattice data on two meson systems by means of effective field theories. In particular I present the results obtained from a reanalysis of the lattice data on the KD(*()) systems, where the states D-s0*(2317) and D-s1*(2460) are found as bound states of KD and KD *, respectively. We confirm the presence of such states in the lattice data and determine the contribution of the KD channel in the wave function of D-s0*(2317) and that of KD* in the wave function of D-s1*(2460). Our findings indicate a large meson-meson component in the two cases. |
Address |
[Martinez Torres, A.] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05508090 Sao Paulo, SP, Brazil, Email: amartine@if.usp.br |
Corporate Author |
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Thesis |
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Publisher |
Springer Wien |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0177-7963 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000448041400002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3772 |
Permanent link to this record |
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Author |
Feijoo, A.; Magas, V.K.; Ramos, A.; Oset, E. |
Title |
A hidden-charm S =-1 pentaquark from the decay Lambda(b) into J/psi eta Lambda states |
Type |
Journal Article |
Year |
2016 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
Volume |
76 |
Issue |
8 |
Pages |
446 - 12pp |
Keywords |
|
Abstract |
The hidden-charm pentaquark P-c(4450) observed recently by the LHCb collaboration may be of molecular nature, as advocated by some unitary approaches that also predict pentaquark partners in the strangeness S = -1 sector. In this work we argue that a hidden-charm strange pentaquark could be seen from the decay of the Lambda b, just as in the case of the non-strange P-c(4450), but looking into the J/psi eta Lambda decay mode and forming the invariant mass spectrum of J/psi Lambda pairs. In the model presented here, which assumes a standard weak decay topology and incorporates the hadronization process and final-state interaction effects, we find the J/psi eta Lambda final states to be populated with similar strength as the J/psi K- p states employed for the observation of the non-strange pentaquark. This makes the Lambda b -> J/psi eta Lambda decay to be an interesting process to observe a possible strange partner of the P-c(4450). We study the dependence of the J/psi Lambda mass spectra on various model ingredients and on the unknown properties of the strange pentaquark. |
Address |
[Feijoo, A.; Magas, V. K.; Ramos, A.] Univ Barcelona, Dept Fis Quant & Astrofis, Inst Ciencies Cosmos ICCUB, Marti & Franques 1, E-08028 Barcelona, Spain, Email: feijoo@icc.ub.edu; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1434-6044 |
ISBN |
|
Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000399606600001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
3058 |
Permanent link to this record |
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Author |
Nada, A.; Ramos, A. |
Title |
An analysis of systematic effects in finite size scaling studies using the gradient flow |
Type |
Journal Article |
Year |
2021 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
Volume |
81 |
Issue |
1 |
Pages |
1 - 19pp |
Keywords |
|
Abstract |
We propose a new strategy for the determination of the step scaling function sigma (u) in finite size scaling studies using the gradient flow. In this approach the determination of sigma (u) is broken in two pieces: a change of the flow time at fixed physical size, and a change of the size of the system at fixed flow time. Using both perturbative arguments and a set of simulations in the pure gauge theory we show that this approach leads to a better control over the continuum extrapolations. Following this new proposal we determine the running coupling at high energies in the pure gauge theory and re-examine the determination of the Lambda -parameter, with special care on the perturbative truncation uncertainties. |
Address |
[Nada, Alessandro] DESY, John von Neumann Inst Comp NIC, Platanenallee 6, D-15738 Zeuthen, Germany, Email: alberto.ramos@cern.ch |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000606481000001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4678 |
Permanent link to this record |
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Author |
Albandea, D.; Hernandez, P.; Ramos, A.; Romero-Lopez, F. |
Title |
Topological sampling through windings |
Type |
Journal Article |
Year |
2021 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
Volume |
81 |
Issue |
10 |
Pages |
873 - 12pp |
Keywords |
|
Abstract |
We propose a modification of the Hybrid Monte Carlo (HMC) algorithm that overcomes the topological freezing of a two-dimensional U(1) gauge theory with and without fermion content. This algorithm includes reversible jumps between topological sectors – winding steps – combined with standard HMC steps. The full algorithm is referred to as winding HMC (wHMC), and it shows an improved behaviour of the autocorrelation time towards the continuum limit. We find excellent agreement between the wHMC estimates of the plaquette and topological susceptibility and the analytical predictions in the U(1) pure gauge theory, which are known even at finite beta. We also study the expectation values in fixed topological sectors using both HMC and wHMC, with and without fermions. Even when topology is frozen in HMC – leading to significant deviations in topological as well as non-topological quantities – the two algorithms agree on the fixed-topology averages. Finally, we briefly compare the wHMC algorithm results to those obtained with master-field simulations of size L similar to 8 x 10(3). |
Address |
[Albandea, David; Hernandez, Pilar; Ramos, Alberto; Romero-Lopez, Fernando] UVEG, CSIC, IFIC, Edificio Inst Invest,Apt 22085, Valencia 46071, Spain, Email: David.Albandea@uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000703880600001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
4979 |
Permanent link to this record |