Pub Date : 2020-10-12DOI: 10.1103/PhysRevC.103.064606
Varinderjit Singh, J. Vadas, T. Steinbach, B. Wiggins, S. Hudan, R. deSouza
Experimental above-barrier fusion cross-sections for 17F + 12C are compared to the fusion excitation functions for 16,18O, 19F, and 20Ne ions on a carbon target. In comparing the different systems both the differing static size of the incident ions and changes in fusion barrier are accounted for by examining the reduced fusion cross-section. Remaining trends of the fusion cross-section above the barrier which reflect the sensitive interplay of the sd protons and neutrons are observed. The experimental data are also compared to both a widely-used analytical model of near-barrier fusion, as well as a time-dependent Hartree-Fock model. Both models fail to describe the trends observed.
{"title":"Assessing the impact of valence \u0000sd\u0000 neutrons and protons on fusion","authors":"Varinderjit Singh, J. Vadas, T. Steinbach, B. Wiggins, S. Hudan, R. deSouza","doi":"10.1103/PhysRevC.103.064606","DOIUrl":"https://doi.org/10.1103/PhysRevC.103.064606","url":null,"abstract":"Experimental above-barrier fusion cross-sections for 17F + 12C are compared to the fusion excitation functions for 16,18O, 19F, and 20Ne ions on a carbon target. In comparing the different systems both the differing static size of the incident ions and changes in fusion barrier are accounted for by examining the reduced fusion cross-section. Remaining trends of the fusion cross-section above the barrier which reflect the sensitive interplay of the sd protons and neutrons are observed. The experimental data are also compared to both a widely-used analytical model of near-barrier fusion, as well as a time-dependent Hartree-Fock model. Both models fail to describe the trends observed.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91494849","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 : 2020-10-12DOI: 10.1103/PHYSREVC.103.044615
B. Asher, S. Almaraz-Calderon, V. Tripathi, K. Kemper, L. Baby, N. Gerken, E. Lopez-Saavedra, A. Morelock, J. Perello, I. Wiedenhöver, N. Keeley
The halo nature of the low-lying $1/2$+ first excited state of the exotic weakly-bound proton drip-line nucleus $^{17}$F has long been hypothesized. The structure of such a halo nucleus would imply special nuclear properties including, possibly, an enhancement in its fusion cross section above the barrier. The total fusion cross section of $^{17}$F + $^{12}$C near the Coulomb barrier was studied using the newly developed "Encore" active-target detector at Florida State University. Total fusion cross sections for the stable counterpart systems $^{16}$O + $^{12}$C and $^{19}$F + $^{12}$C were also measured to enable a systematic comparison. No influence of the halo nature of the $^{17}$F $1/2$+ first excited state on its fusion excitation function was observed when compared with the stable counterpart systems.
{"title":"Experimental study of the \u0000F17+C12\u0000 fusion reaction and its implications for fusion of proton-halo systems","authors":"B. Asher, S. Almaraz-Calderon, V. Tripathi, K. Kemper, L. Baby, N. Gerken, E. Lopez-Saavedra, A. Morelock, J. Perello, I. Wiedenhöver, N. Keeley","doi":"10.1103/PHYSREVC.103.044615","DOIUrl":"https://doi.org/10.1103/PHYSREVC.103.044615","url":null,"abstract":"The halo nature of the low-lying $1/2$+ first excited state of the exotic weakly-bound proton drip-line nucleus $^{17}$F has long been hypothesized. The structure of such a halo nucleus would imply special nuclear properties including, possibly, an enhancement in its fusion cross section above the barrier. The total fusion cross section of $^{17}$F + $^{12}$C near the Coulomb barrier was studied using the newly developed \"Encore\" active-target detector at Florida State University. Total fusion cross sections for the stable counterpart systems $^{16}$O + $^{12}$C and $^{19}$F + $^{12}$C were also measured to enable a systematic comparison. No influence of the halo nature of the $^{17}$F $1/2$+ first excited state on its fusion excitation function was observed when compared with the stable counterpart systems.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82088073","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}
The measurement of (anti)nuclei production in pp, p-A and A-A collisions at ultrarelativistic energies is important to understand hadronization. The excellent tracking and particle identification capabilities of ALICE make it the most suited detector at the LHC to study light (anti)nuclei produced in high-energy hadronic collisions. (Anti)nuclei with mass numbers up to 4, such as (anti)deuterons, (anti)tritons, (anti)$^3$He and (anti)$^4$He have been successfully identified in ALICE at midrapidity ($|eta|<$0.9). In this contribution, multiplicity dependent results on the yields, nuclei-to-protons ratios as well as the coalescence parameter $B_{mathrm A}$ as a function of the charged-particle multiplicity are presented and compared with the expectations of coalescence and statistical hadronization models (SHM) to provide insight into their production mechanism in heavy-ion collisions.
{"title":"Light (anti)nuclei production in high energy nuclear collisions at the LHC with ALICE","authors":"C. Pinto","doi":"10.22323/1.382.0239","DOIUrl":"https://doi.org/10.22323/1.382.0239","url":null,"abstract":"The measurement of (anti)nuclei production in pp, p-A and A-A collisions at ultrarelativistic energies is important to understand hadronization. The excellent tracking and particle identification capabilities of ALICE make it the most suited detector at the LHC to study light (anti)nuclei produced in high-energy hadronic collisions. (Anti)nuclei with mass numbers up to 4, such as (anti)deuterons, (anti)tritons, (anti)$^3$He and (anti)$^4$He have been successfully identified in ALICE at midrapidity ($|eta|<$0.9). In this contribution, multiplicity dependent results on the yields, nuclei-to-protons ratios as well as the coalescence parameter $B_{mathrm A}$ as a function of the charged-particle multiplicity are presented and compared with the expectations of coalescence and statistical hadronization models (SHM) to provide insight into their production mechanism in heavy-ion collisions.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90241643","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}
P. Belli, R. Bernabei, V. Brudanin, F. Cappella, V. Caracciolo, R. Cerulli, F. Danevich, A. Incicchitti, D. Kasperovych, V. R. Klavdiienko, V. Kobychev, V. Merlo, O. Polischuk, V. Tretyak, M. Zarytskyy
Studies on double beta decay processes in $^{106}$Cd were performed by using a cadmium tungstate scintillator enriched in $^{106}$Cd at 66% ($^{106}$CdWO$_4$) with two CdWO$_4$ scintillation counters (with natural Cd composition). No effect was observed in the data accumulated over 26033 h. New improved half-life limits were set on the different channels and modes of the $^{106}$Cd double beta decay at level of $lim T_{1/2}sim 10^{20}-10^{22}$ yr. The limit for the two neutrino electron capture with positron emission in $^{106}$Cd to the ground state of $^{106}$Pd, $T^{2numathrm{EC}beta^+}_{1/2}geq2.1times 10^{21}$ yr, was set by the analysis of the $^{106}$CdWO$_4$ data in coincidence with the energy release 511 keV in both CdWO$_4$ counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range $T_{1/2}sim10^{21}-10^{22}$ yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of $^{106}$Pd is restricted at the level of $T^{0numathrm{2K}}_{1/2}geq2.9times10^{21}$ yr
利用66度富集$^{106}$ Cd的钨酸镉闪烁体，研究了$^{106}$ Cd的双β衰变过程% ($^{106}$CdWO$_4$) with two CdWO$_4$ scintillation counters (with natural Cd composition). No effect was observed in the data accumulated over 26033 h. New improved half-life limits were set on the different channels and modes of the $^{106}$Cd double beta decay at level of $lim T_{1/2}sim 10^{20}-10^{22}$ yr. The limit for the two neutrino electron capture with positron emission in $^{106}$Cd to the ground state of $^{106}$Pd, $T^{2numathrm{EC}beta^+}_{1/2}geq2.1times 10^{21}$ yr, was set by the analysis of the $^{106}$CdWO$_4$ data in coincidence with the energy release 511 keV in both CdWO$_4$ counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range $T_{1/2}sim10^{21}-10^{22}$ yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of $^{106}$Pd is restricted at the level of $T^{0numathrm{2K}}_{1/2}geq2.9times10^{21}$ yr
{"title":"Search for Double Beta Decay of 106Cd with an Enriched 106CdWO4 Crystal Scintillator in Coincidence with CdWO4 Scintillation Counters","authors":"P. Belli, R. Bernabei, V. Brudanin, F. Cappella, V. Caracciolo, R. Cerulli, F. Danevich, A. Incicchitti, D. Kasperovych, V. R. Klavdiienko, V. Kobychev, V. Merlo, O. Polischuk, V. Tretyak, M. Zarytskyy","doi":"10.3390/universe6100182","DOIUrl":"https://doi.org/10.3390/universe6100182","url":null,"abstract":"Studies on double beta decay processes in $^{106}$Cd were performed by using a cadmium tungstate scintillator enriched in $^{106}$Cd at 66% ($^{106}$CdWO$_4$) with two CdWO$_4$ scintillation counters (with natural Cd composition). No effect was observed in the data accumulated over 26033 h. New improved half-life limits were set on the different channels and modes of the $^{106}$Cd double beta decay at level of $lim T_{1/2}sim 10^{20}-10^{22}$ yr. The limit for the two neutrino electron capture with positron emission in $^{106}$Cd to the ground state of $^{106}$Pd, $T^{2numathrm{EC}beta^+}_{1/2}geq2.1times 10^{21}$ yr, was set by the analysis of the $^{106}$CdWO$_4$ data in coincidence with the energy release 511 keV in both CdWO$_4$ counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range $T_{1/2}sim10^{21}-10^{22}$ yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of $^{106}$Pd is restricted at the level of $T^{0numathrm{2K}}_{1/2}geq2.9times10^{21}$ yr","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83008070","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}
Cheuk-Ping Wong, Xuan Li, M. Brooks, Matthew J. Durham, Ming Liu, A. Morreale, Cesar Luiz Da Silva, W. Sondheim
The future Electron-Ion Collider (EIC) will explore several fundamental questions in a broad Bjorken-x ($x_{BJ}$) and $Q^{2}$ phase space. Heavy flavor and jet products are ideal probes to precisely study the tomography of nucleon/nuclei structure, help solve the proton spin puzzle and understand the hadronizaton processes in vacuum or in the QCD medium. Due to the asymmetric collisions at the EIC, most of the final state hadrons are produced in the nucleon/nuclei beam going (forward) direction. A silicon vertex/tracking is critical to precisely measure these forward hadrons at the EIC. Details of different conceptual designs of the proposed Forward Silicon Tracker (FST) and the relevant detector performance are presented in this technical note. The associated heavy flavor and jet studies with the evaluated FST performance are discussed as well.
{"title":"A Proposed Forward Silicon Tracker for the Future Electron-Ion Collider and Associated Physics Studies","authors":"Cheuk-Ping Wong, Xuan Li, M. Brooks, Matthew J. Durham, Ming Liu, A. Morreale, Cesar Luiz Da Silva, W. Sondheim","doi":"10.2172/1659154","DOIUrl":"https://doi.org/10.2172/1659154","url":null,"abstract":"The future Electron-Ion Collider (EIC) will explore several fundamental questions in a broad Bjorken-x ($x_{BJ}$) and $Q^{2}$ phase space. Heavy flavor and jet products are ideal probes to precisely study the tomography of nucleon/nuclei structure, help solve the proton spin puzzle and understand the hadronizaton processes in vacuum or in the QCD medium. Due to the asymmetric collisions at the EIC, most of the final state hadrons are produced in the nucleon/nuclei beam going (forward) direction. A silicon vertex/tracking is critical to precisely measure these forward hadrons at the EIC. Details of different conceptual designs of the proposed Forward Silicon Tracker (FST) and the relevant detector performance are presented in this technical note. The associated heavy flavor and jet studies with the evaluated FST performance are discussed as well.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75374723","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 : 2020-09-03DOI: 10.1103/PHYSREVC.103.044902
S. Kagamaster, R. Reed, M. Lisa
Recently, Chatterjee et al used a hadronic transport model to estimate the resolution with which various experimental quantities select the impact parameter of relativistic heavy ion collisions at collision energies relevant to the Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider (RHIC). Measures based on particle multiplicity at forward rapidity were found to be significantly worse than those based on midrapidity multiplicity. Using the same model, we show that a slightly more sophisticated measure greatly improves the resolution based on forward rapidity particles; this improvement persists even when the model is filtered through a realistic simulation of a recent upgrade detector to the STAR experiment. These results highlight the importance of optimizing centrality measures based on particles detected at forward rapidity, especially for experimental studies that search for a critical point in the QCD phase diagram. Such measurements usually focus on proton multiplicity fluctuations at midrapidity, hence selecting events based on multiplicity at midrapidity raises the possibility of nontrivial autocorrelations.
{"title":"Centrality determination with a forward detector in the RHIC Beam Energy Scan","authors":"S. Kagamaster, R. Reed, M. Lisa","doi":"10.1103/PHYSREVC.103.044902","DOIUrl":"https://doi.org/10.1103/PHYSREVC.103.044902","url":null,"abstract":"Recently, Chatterjee et al used a hadronic transport model to estimate the resolution with which various experimental quantities select the impact parameter of relativistic heavy ion collisions at collision energies relevant to the Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider (RHIC). Measures based on particle multiplicity at forward rapidity were found to be significantly worse than those based on midrapidity multiplicity. Using the same model, we show that a slightly more sophisticated measure greatly improves the resolution based on forward rapidity particles; this improvement persists even when the model is filtered through a realistic simulation of a recent upgrade detector to the STAR experiment. These results highlight the importance of optimizing centrality measures based on particles detected at forward rapidity, especially for experimental studies that search for a critical point in the QCD phase diagram. Such measurements usually focus on proton multiplicity fluctuations at midrapidity, hence selecting events based on multiplicity at midrapidity raises the possibility of nontrivial autocorrelations.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75500224","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 : 2020-08-13DOI: 10.1051/EPJCONF/202022701020
D. Schumann, R. Dressler, U. Koester, M. Paul
The Authors of this Comment were integral part of the design and execution of the experiments reported by M. Gai et al. in the Conference Proceedings entitled "The interaction of neutrons with $^7$Be at BBN temperatures: Lack of Standard Nuclear Solution to the "Primordial $^7$Li Problem". They reject the interpretation of the experiments presented by M. Gai et al. and disavow the extraction of any physical quantity from its results owing to inadequate calibration of tracks formed in CR-39 detectors and to uncontrolled background.
{"title":"Comment on: The interaction of neutrons with 7Be at BBN temperatures: Lack of Standard Nuclear Solution to the \"Primordial 7Li Problem\" by M. Gai et al.","authors":"D. Schumann, R. Dressler, U. Koester, M. Paul","doi":"10.1051/EPJCONF/202022701020","DOIUrl":"https://doi.org/10.1051/EPJCONF/202022701020","url":null,"abstract":"The Authors of this Comment were integral part of the design and execution of the experiments reported by M. Gai et al. in the Conference Proceedings entitled \"The interaction of neutrons with $^7$Be at BBN temperatures: Lack of Standard Nuclear Solution to the \"Primordial $^7$Li Problem\". They reject the interpretation of the experiments presented by M. Gai et al. and disavow the extraction of any physical quantity from its results owing to inadequate calibration of tracks formed in CR-39 detectors and to uncontrolled background.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76293753","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}
The production of light neutral mesons in different collision systems is interesting for a variety of reasons: In nucleus-nucleus (AA) collisions the measurements provide important information on the energy loss of partons traversing the Quark-Gluon Plasma (QGP) which is formed in heavy-ion collisions at the LHC. In proton--proton (pp) collisions, neutral mesons allow us to test with high precision the predictions of perturbative QCD and other model calculations, and also serve as a reference for pA and AA collisions. In pA collisions, cold nuclear matter effects are studied. In the ALICE experiment, which is dedicated to the study of the QGP, neutral mesons can be detected via their decay to two photons. The latter can be reconstructed using the two calorimeters EMCal and PHOS or via conversions in the detector material. Combining state-of-the-art reconstruction techniques with the large data sample delivered by the LHC in Run 2 gives us the opportunity to enhance the precision of our measurements. In these proceedings, an overview of neutral meson production in pp, p--Pb and Pb--Pb collisions at LHC energies, as measured with the ALICE detector is presented.
{"title":"Light neutral meson production in the era of precision physics at the LHC","authors":"M. Sas","doi":"10.22323/1.364.0303","DOIUrl":"https://doi.org/10.22323/1.364.0303","url":null,"abstract":"The production of light neutral mesons in different collision systems is interesting for a variety of reasons: In nucleus-nucleus (AA) collisions the measurements provide important information on the energy loss of partons traversing the Quark-Gluon Plasma (QGP) which is formed in heavy-ion collisions at the LHC. In proton--proton (pp) collisions, neutral mesons allow us to test with high precision the predictions of perturbative QCD and other model calculations, and also serve as a reference for pA and AA collisions. In pA collisions, cold nuclear matter effects are studied. In the ALICE experiment, which is dedicated to the study of the QGP, neutral mesons can be detected via their decay to two photons. The latter can be reconstructed using the two calorimeters EMCal and PHOS or via conversions in the detector material. Combining state-of-the-art reconstruction techniques with the large data sample delivered by the LHC in Run 2 gives us the opportunity to enhance the precision of our measurements. In these proceedings, an overview of neutral meson production in pp, p--Pb and Pb--Pb collisions at LHC energies, as measured with the ALICE detector is presented.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73289678","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 : 2020-07-13DOI: 10.1103/physrevc.102.044004
C. Fritzsch, S. Barsov, I. Burmeister, S. Dymov, R. Gebel, M. Hartmann, A. Kacharava, A. Khoukaz, V. Komarov, P. Kulessa, A. Kulikov, A. Lehrach, B. Lorentz, D. Mchedlishvili, T. Mersmann, M. Mielke, S. Mikirtychiants, M. Nioradze, H. Ohm, M. Papenbrock, D. Prasuhn, V. Serdyuk, H. Ströher, A. Täschner, Y. Valdau, C. Wilkin
New high precision total and differential cross sections are reported for the $dpto {}^3textrm{He},eta$ reaction close to threshold. The measurements were performed using the magnetic spectrometer ANKE, which is an internal fixed target facility at the COSY cooler synchrotron. The data were taken for deuteron beam momenta between $3.14641~textrm{GeV}/c$ and $3.20416~textrm{GeV}/c$, which corresponds to the range in excess energy $Q$ for this reaction between $1.14~textrm{MeV}$ and $15.01~textrm{MeV}$. The normalization was established through the measurement in parallel of deuteron-proton elastic scattering and this was checked through the study of the $dpto {}^3textrm{He},pi^0$ reaction. The previously indicated possible change of sign of the slope of the differential cross sections near the production threshold, which could be explained by a rapid variation of the $s$- and $p$-wave interference term, is not confirmed by the new data. The energy dependence of the total cross section and the $90^{circ}$ slope parameter are well explained by describing the final state interaction in terms of a complex Jost function and the results are significant in the discussion of $eta$-mesic nuclei. In combination with recently published WASA-at-COSY data [P. Adlarson $et, al.$, Phys. Lett. B 782, 297 (2018)], a smooth variation of the slope parameter is achieved up to an excess energy of $80.9~textrm{MeV}$.
{"title":"Total and differential cross sections of the \u0000dp→He3η\u0000 reaction at excess energies between 1 and 15 MeV","authors":"C. Fritzsch, S. Barsov, I. Burmeister, S. Dymov, R. Gebel, M. Hartmann, A. Kacharava, A. Khoukaz, V. Komarov, P. Kulessa, A. Kulikov, A. Lehrach, B. Lorentz, D. Mchedlishvili, T. Mersmann, M. Mielke, S. Mikirtychiants, M. Nioradze, H. Ohm, M. Papenbrock, D. Prasuhn, V. Serdyuk, H. Ströher, A. Täschner, Y. Valdau, C. Wilkin","doi":"10.1103/physrevc.102.044004","DOIUrl":"https://doi.org/10.1103/physrevc.102.044004","url":null,"abstract":"New high precision total and differential cross sections are reported for the $dpto {}^3textrm{He},eta$ reaction close to threshold. The measurements were performed using the magnetic spectrometer ANKE, which is an internal fixed target facility at the COSY cooler synchrotron. The data were taken for deuteron beam momenta between $3.14641~textrm{GeV}/c$ and $3.20416~textrm{GeV}/c$, which corresponds to the range in excess energy $Q$ for this reaction between $1.14~textrm{MeV}$ and $15.01~textrm{MeV}$. The normalization was established through the measurement in parallel of deuteron-proton elastic scattering and this was checked through the study of the $dpto {}^3textrm{He},pi^0$ reaction. The previously indicated possible change of sign of the slope of the differential cross sections near the production threshold, which could be explained by a rapid variation of the $s$- and $p$-wave interference term, is not confirmed by the new data. The energy dependence of the total cross section and the $90^{circ}$ slope parameter are well explained by describing the final state interaction in terms of a complex Jost function and the results are significant in the discussion of $eta$-mesic nuclei. In combination with recently published WASA-at-COSY data [P. Adlarson $et, al.$, Phys. Lett. B 782, 297 (2018)], a smooth variation of the slope parameter is achieved up to an excess energy of $80.9~textrm{MeV}$.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81699999","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}
The $^{2}$H$(e,e'p)n$ cross sections have been measured at negative 4-momentum transfers of $Q^{2} = 4.5pm0.5$ (GeV/c)$^{2}$ and $Q^{2} = 3.5pm0.5$ (GeV/c)$^{2}$ reaching neutron recoil (missing) momenta up to $p_{mathrm{r}}sim$1.0 GeV/c. The data have been obtained at fixed neutron recoil angles $5^{circ}leqtheta_{nq}leq95^{circ}$ with respect to the 3-momentum transfer $vec{q}$. The new data agree well with the previous data which reached $p_{mathrm{r}}sim550$ MeV/c. At $theta_{nq}=35^{circ}$ and $45^{circ}$, final state interactions (FSI), meson exchange currents (MEC) and isobar configurations (IC) are suppressed and the plane wave impulse approximation (PWIA) provides the dominant cross section contribution. The new data are compared to recent theoretical calculations, and a significant disagreement for recoil momenta $p_{mathrm{r}}>700$ MeV/c is observed.
{"title":"Cross section measurements of deuteron electro-disintegration at very high recoil momenta and large 4-momentum transfers (Q^2)","authors":"C. Yero","doi":"10.2172/1644044","DOIUrl":"https://doi.org/10.2172/1644044","url":null,"abstract":"The $^{2}$H$(e,e'p)n$ cross sections have been measured at negative 4-momentum transfers of $Q^{2} = 4.5pm0.5$ (GeV/c)$^{2}$ and $Q^{2} = 3.5pm0.5$ (GeV/c)$^{2}$ reaching neutron recoil (missing) momenta up to $p_{mathrm{r}}sim$1.0 GeV/c. The data have been obtained at fixed neutron recoil angles $5^{circ}leqtheta_{nq}leq95^{circ}$ with respect to the 3-momentum transfer $vec{q}$. The new data agree well with the previous data which reached $p_{mathrm{r}}sim550$ MeV/c. At $theta_{nq}=35^{circ}$ and $45^{circ}$, final state interactions (FSI), meson exchange currents (MEC) and isobar configurations (IC) are suppressed and the plane wave impulse approximation (PWIA) provides the dominant cross section contribution. The new data are compared to recent theoretical calculations, and a significant disagreement for recoil momenta $p_{mathrm{r}}>700$ MeV/c is observed.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87441017","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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