Pub Date : 2019-01-01DOI: 10.1142/S2010194519600103
M. Cognata, S. Cherubini, M. Gulino, L. Lamia, R. Pizzone, S. Romano, C. Spitaleri, A. Tumino
Resonant reactions play an important role in astrophysics as they might significantly enhance the cross section with respect to the direct reaction contribution and alter the nucleosynthetic flow. Moreover, resonances bear information about states in the intermediate compound nucleus formed in the reaction. However, nuclear reactions in stars take place at energies well below [Formula: see text] MeV and the Coulomb barrier, exponentially suppressing the cross section, and the electron screening effect, due to the shielding of nuclear charges by atomic electrons, make it very difficult to provide accurate input data for astrophysics. Therefore, indirect methods have been introduced; in particular, we will focus on the Trojan Horse Method. We will briefly discuss the theory behind the method, to make clear its domain of applicability, the advantages and the drawbacks, and two recent cases will be shortly reviewed: the [Formula: see text] reaction, which is an important fluorine destruction channel in the proton-rich outer layers of asymptotic giant branch (AGB) stars, and the [Formula: see text] reactions, which play a critical role in astrophysics to understand stellar burning scenarios in carbon-rich environments.
{"title":"Nuclear astrophysics and resonant reactions: Exploring the threshold region with the Trojan Horse Method","authors":"M. Cognata, S. Cherubini, M. Gulino, L. Lamia, R. Pizzone, S. Romano, C. Spitaleri, A. Tumino","doi":"10.1142/S2010194519600103","DOIUrl":"https://doi.org/10.1142/S2010194519600103","url":null,"abstract":"Resonant reactions play an important role in astrophysics as they might significantly enhance the cross section with respect to the direct reaction contribution and alter the nucleosynthetic flow. Moreover, resonances bear information about states in the intermediate compound nucleus formed in the reaction. However, nuclear reactions in stars take place at energies well below [Formula: see text] MeV and the Coulomb barrier, exponentially suppressing the cross section, and the electron screening effect, due to the shielding of nuclear charges by atomic electrons, make it very difficult to provide accurate input data for astrophysics. Therefore, indirect methods have been introduced; in particular, we will focus on the Trojan Horse Method. We will briefly discuss the theory behind the method, to make clear its domain of applicability, the advantages and the drawbacks, and two recent cases will be shortly reviewed: the [Formula: see text] reaction, which is an important fluorine destruction channel in the proton-rich outer layers of asymptotic giant branch (AGB) stars, and the [Formula: see text] reactions, which play a critical role in astrophysics to understand stellar burning scenarios in carbon-rich environments.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84163449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S2010194519600127
R. Pizzone, R. Spartá, M. Cognata, L. Lamia, C. Spitaleri, C. Bertulani, A. Tumino
Big Bang Nucleosynthesis (BBN) requires several nuclear physics inputs and nuclear reaction rates. An up-to-date compilation of direct cross sections of [Formula: see text], [Formula: see text]He and [Formula: see text]He reactions is given, being these ones among the most uncertain bare-nucleus cross sections. An intense experimental effort has been carried on in the last decade to apply the Trojan Horse Method (THM) to study reactions of relevance for the BBN and measure their astrophysical S(E)-factor. The reaction rates and the relative error for the four reactions of interest are then numerically calculated in the temperature ranges of relevance for BBN [Formula: see text]. These value were then used as input physics for primordial nucleosynthesis calculations in order to evaluate their impact on the calculated primordial abundances and isotopical composition for H, He and Li. New results on the [Formula: see text]He reaction rate were also taken into account.These were compared with the observational primordial abundance estimates in different astrophysical sites. Reactions to be studied in perspective will also be discussed.
{"title":"Nuclear physics and its role for describing the early universe","authors":"R. Pizzone, R. Spartá, M. Cognata, L. Lamia, C. Spitaleri, C. Bertulani, A. Tumino","doi":"10.1142/S2010194519600127","DOIUrl":"https://doi.org/10.1142/S2010194519600127","url":null,"abstract":"Big Bang Nucleosynthesis (BBN) requires several nuclear physics inputs and nuclear reaction rates. An up-to-date compilation of direct cross sections of [Formula: see text], [Formula: see text]He and [Formula: see text]He reactions is given, being these ones among the most uncertain bare-nucleus cross sections. An intense experimental effort has been carried on in the last decade to apply the Trojan Horse Method (THM) to study reactions of relevance for the BBN and measure their astrophysical S(E)-factor. The reaction rates and the relative error for the four reactions of interest are then numerically calculated in the temperature ranges of relevance for BBN [Formula: see text]. These value were then used as input physics for primordial nucleosynthesis calculations in order to evaluate their impact on the calculated primordial abundances and isotopical composition for H, He and Li. New results on the [Formula: see text]He reaction rate were also taken into account.These were compared with the observational primordial abundance estimates in different astrophysical sites. Reactions to be studied in perspective will also be discussed.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88328057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S2010194519600012
A. Giacomo
The mechanism of colour confinement by dual superconductivity of the [Formula: see text] vacuum is discussed. Its gauge invariant formulation and the recent improvements in its lattice verification are reported.
讨论了[公式:见文]真空双超导色约束的机理。本文报道了它的规范不变量公式及其晶格验证的最新改进。
{"title":"Monopoles and confinement: New results and state of the art","authors":"A. Giacomo","doi":"10.1142/S2010194519600012","DOIUrl":"https://doi.org/10.1142/S2010194519600012","url":null,"abstract":"The mechanism of colour confinement by dual superconductivity of the [Formula: see text] vacuum is discussed. Its gauge invariant formulation and the recent improvements in its lattice verification are reported.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78065184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S201019451960005X
Y. Yamaguchi
Exotic hadrons reported in the heavy flavor sector have attracted much interest in hadron and nuclear physics. Especially near the thresholds, the hadron-hadron interaction is important to understand these exotic structures. In this talk, the short range [Formula: see text] potential whose importance is indicated by the Lattice QCD is studied by the [Formula: see text] meson exchange model, and the Born-order quark exchange model. We find the large difference between the results of the [Formula: see text] meson exchange and the quark exchange calculations.
{"title":"Short range interaction in πJ/ψ − DD̄∗ channel","authors":"Y. Yamaguchi","doi":"10.1142/S201019451960005X","DOIUrl":"https://doi.org/10.1142/S201019451960005X","url":null,"abstract":"Exotic hadrons reported in the heavy flavor sector have attracted much interest in hadron and nuclear physics. Especially near the thresholds, the hadron-hadron interaction is important to understand these exotic structures. In this talk, the short range [Formula: see text] potential whose importance is indicated by the Lattice QCD is studied by the [Formula: see text] meson exchange model, and the Born-order quark exchange model. We find the large difference between the results of the [Formula: see text] meson exchange and the quark exchange calculations.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77313301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S2010194519600115
S. Palmerini, G. D’Agata, M. Cognata, R. Pizzone, I. Indelicato, O. Trippella, D. Vescovi
In the last years the [Formula: see text]O and the [Formula: see text]F([Formula: see text],p)[Formula: see text]Ne reactions have been studied via the Trojan Horse Method in the energy range of interest for astrophysics. These are the first experimental data available for the main channels of [Formula: see text]F destruction that entirely cover the energy regions typical of the stellar H- and He- burning. In both cases the reaction rates are significantly larger than the previous estimations available in the literature. We present here a re-analysis of the fluorine nucleosynthesis in Asymptotic Giant Branch stars by employing in state-of-the-art models of stellar nucleosynthesis the THM reaction rates for [Formula: see text]F destruction.
{"title":"On the fluorine nucleosynthesis in AGB stars in the light of the 19F(p,α)16O and 19F(α,p)22Ne reaction rate measured via THM","authors":"S. Palmerini, G. D’Agata, M. Cognata, R. Pizzone, I. Indelicato, O. Trippella, D. Vescovi","doi":"10.1142/S2010194519600115","DOIUrl":"https://doi.org/10.1142/S2010194519600115","url":null,"abstract":"In the last years the [Formula: see text]O and the [Formula: see text]F([Formula: see text],p)[Formula: see text]Ne reactions have been studied via the Trojan Horse Method in the energy range of interest for astrophysics. These are the first experimental data available for the main channels of [Formula: see text]F destruction that entirely cover the energy regions typical of the stellar H- and He- burning. In both cases the reaction rates are significantly larger than the previous estimations available in the literature. We present here a re-analysis of the fluorine nucleosynthesis in Asymptotic Giant Branch stars by employing in state-of-the-art models of stellar nucleosynthesis the THM reaction rates for [Formula: see text]F destruction.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91104106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S2010194519600036
M. Musakhanov, N. Rakhimov
Within the framework of the instanton Liquid Model (ILM) we evaluate the heavy quark [Formula: see text] potential at finite temperature. The potential in the ILM has two components: direct instantons contribution and the ILM modified one-gluon exchange contribution. The dynamical ”electric” mass [Formula: see text], which was generated by rescattering of the gluons from the ILM instantons, was taken into account.
{"title":"Heavy quarkonium potential at nonzero temperature in the instanton liquid model","authors":"M. Musakhanov, N. Rakhimov","doi":"10.1142/S2010194519600036","DOIUrl":"https://doi.org/10.1142/S2010194519600036","url":null,"abstract":"Within the framework of the instanton Liquid Model (ILM) we evaluate the heavy quark [Formula: see text] potential at finite temperature. The potential in the ILM has two components: direct instantons contribution and the ILM modified one-gluon exchange contribution. The dynamical ”electric” mass [Formula: see text], which was generated by rescattering of the gluons from the ILM instantons, was taken into account.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85013579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S2010194519600152
E. M. Tursunov, A. Kadyrov
The astrophysical S-factor for the direct [Formula: see text] capture reaction is calculated in a three-body model based on the hyperspherical Lagrange-mesh method. A sensitivity of the E1 and E2 astrophysical S-factors to the orthogonalization method of Pauli forbidden states in the three-body system is studied. It is found that the method of orthogonalising pseudopotentials (OPP) yields larger isotriplet ([Formula: see text]) components than the supersymmetric transformation (SUSY) procedure. The E1 astrophysical S-factor shows the same energy dependence in both cases, but strongly different absolute values. At the same time, the E2 S-factor does not depend on the orthogonalization procedure. As a result, the OPP method yields a very good description of the direct data of the LUNA collaboration at low energies, while the SUSY transformation strongly underestimates the LUNA data.
{"title":"Influence of orthogonalization procedure on astrophysical S-factor for the direct α + d →6Li + γ capture process in a three-body model","authors":"E. M. Tursunov, A. Kadyrov","doi":"10.1142/S2010194519600152","DOIUrl":"https://doi.org/10.1142/S2010194519600152","url":null,"abstract":"The astrophysical S-factor for the direct [Formula: see text] capture reaction is calculated in a three-body model based on the hyperspherical Lagrange-mesh method. A sensitivity of the E1 and E2 astrophysical S-factors to the orthogonalization method of Pauli forbidden states in the three-body system is studied. It is found that the method of orthogonalising pseudopotentials (OPP) yields larger isotriplet ([Formula: see text]) components than the supersymmetric transformation (SUSY) procedure. The E1 astrophysical S-factor shows the same energy dependence in both cases, but strongly different absolute values. At the same time, the E2 S-factor does not depend on the orthogonalization procedure. As a result, the OPP method yields a very good description of the direct data of the LUNA collaboration at low energies, while the SUSY transformation strongly underestimates the LUNA data.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"134 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77386165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S2010194519600139
S. Artemov, S. Igamov, A. Karakhodzhaev, O. R. Tojiboyev, F. Ergashev, N. Burtebayev, I. Kholbaev, R. F. Rumi, Sh. Kh. Eshkobilov, R. I. Khalikov
The original version of the activation method is presented and yield of the astrophysical relevant reaction [Formula: see text] has been measured at the energy region 190–650[Formula: see text]keV using this method. The rate of this reaction was calculated within the temperature region [Formula: see text] through the yield values. The possibility of improving the method for measuring very small yields or cross sections was demonstrated.
{"title":"Modificated activation method for measurement of the yield of the astrophysical reactions","authors":"S. Artemov, S. Igamov, A. Karakhodzhaev, O. R. Tojiboyev, F. Ergashev, N. Burtebayev, I. Kholbaev, R. F. Rumi, Sh. Kh. Eshkobilov, R. I. Khalikov","doi":"10.1142/S2010194519600139","DOIUrl":"https://doi.org/10.1142/S2010194519600139","url":null,"abstract":"The original version of the activation method is presented and yield of the astrophysical relevant reaction [Formula: see text] has been measured at the energy region 190–650[Formula: see text]keV using this method. The rate of this reaction was calculated within the temperature region [Formula: see text] through the yield values. The possibility of improving the method for measuring very small yields or cross sections was demonstrated.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"127 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77438378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1142/S2010194519600024
S. Iwasaki, M. Oka, K. Suzuki, T. Yoshida
The Hadronic Paschen-Back effect (HPBE) is a new phenomenon induced by the interplay between finite orbital angular momenta of hadrons and external strong magnetic fields. We review the HPBE in P-wave charmonia and show its mass spectra, deformed wave functions, and mixing ratios, which are evaluated by the constituent quark models in a magnetic field and the cylindrical Gaussian expansion method.
{"title":"Hadronic Paschen-Back effect in P-wave charmonia under strong magnetic fields","authors":"S. Iwasaki, M. Oka, K. Suzuki, T. Yoshida","doi":"10.1142/S2010194519600024","DOIUrl":"https://doi.org/10.1142/S2010194519600024","url":null,"abstract":"The Hadronic Paschen-Back effect (HPBE) is a new phenomenon induced by the interplay between finite orbital angular momenta of hadrons and external strong magnetic fields. We review the HPBE in P-wave charmonia and show its mass spectra, deformed wave functions, and mixing ratios, which are evaluated by the constituent quark models in a magnetic field and the cylindrical Gaussian expansion method.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88758792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-22DOI: 10.1142/S2010194519600164
R. Yarmukhamedov, K. Tursunmakhatov, N. Burtebayev
An asymptotic theory is proposed for the peripheral transfer [Formula: see text] reaction at low energies within the three-body ([Formula: see text], [Formula: see text] and [Formula: see text]) model by combining the dispersion theory and DWBA, where [Formula: see text], [Formula: see text] and [Formula: see text] is a transferred particle. The contribution of the three-body ([Formula: see text], [Formula: see text] and [Formula: see text]) Coulomb dynamics of the transfer mechanism both to the peripheral partial amplitudes for the partial wave [Formula: see text] and to the DWBA amplitude is investigated. The results of the analysis of the differential cross sections of the specific proton transfer reactions at above-barrier energies are presented. New estimates and their uncertainties are obtained for values of the asymptotic normalization coefficients for [Formula: see text] and [Formula: see text] as well as for the direct astrophysical [Formula: see text] factors at stellar energy of the radiative capture [Formula: see text] and [Formula: see text] reactions.
{"title":"Asymptotic theory of charged particle transfer reactions at low energies and nuclear astrophysics","authors":"R. Yarmukhamedov, K. Tursunmakhatov, N. Burtebayev","doi":"10.1142/S2010194519600164","DOIUrl":"https://doi.org/10.1142/S2010194519600164","url":null,"abstract":"An asymptotic theory is proposed for the peripheral transfer [Formula: see text] reaction at low energies within the three-body ([Formula: see text], [Formula: see text] and [Formula: see text]) model by combining the dispersion theory and DWBA, where [Formula: see text], [Formula: see text] and [Formula: see text] is a transferred particle. The contribution of the three-body ([Formula: see text], [Formula: see text] and [Formula: see text]) Coulomb dynamics of the transfer mechanism both to the peripheral partial amplitudes for the partial wave [Formula: see text] and to the DWBA amplitude is investigated. The results of the analysis of the differential cross sections of the specific proton transfer reactions at above-barrier energies are presented. New estimates and their uncertainties are obtained for values of the asymptotic normalization coefficients for [Formula: see text] and [Formula: see text] as well as for the direct astrophysical [Formula: see text] factors at stellar energy of the radiative capture [Formula: see text] and [Formula: see text] reactions.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77318833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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