A search for the critical behavior of strongly interacting matter was performed at the NA61/SHINE experiment by studying event-by-event fluctuations of multiplicity and transverse momentum of charged hadrons produced in inelastic p+p collisions at 20, 31, 40, 80 and 158 GeV/c beam momentum. Results for the energy dependence of the scaled variance of the multiplicity distribution and for two families of strongly intensive are presented. These quantities were studied in different pseudorapidity intervals, which correspond to changing the baryon chemical potential and the temperature at the freeze-out stage. The strongly intensive measures Δ[
{"title":"Pseudorapidity Dependence of Multiplicity and Transverse Momentum Fluctuations in pp Collisions at SPS Energies","authors":"D. Prokhorova","doi":"10.18502/ken.v3i1.1747","DOIUrl":"https://doi.org/10.18502/ken.v3i1.1747","url":null,"abstract":"A search for the critical behavior of strongly interacting matter was performed at the NA61/SHINE experiment by studying event-by-event fluctuations of multiplicity and transverse momentum of charged hadrons produced in inelastic p+p collisions at 20, 31, 40, 80 and 158 GeV/c beam momentum. Results for the energy dependence of the scaled variance of the multiplicity distribution and for two families of strongly intensive are presented. These quantities were studied in different pseudorapidity intervals, which correspond to changing the baryon chemical potential and the temperature at the freeze-out stage. The strongly intensive measures Δ[","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89782349","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}
Recent STAR measurements of the anisotropic flow coefficients, v$_{n}$, are presented for Au+Au collisions spanning the beam energy range $sqrt{s_{NN}} = 7.7 - 200$~GeV. The measurements indicate dependences on harmonic number, $n$, transverse momentum ($p_T$), pseudorapidity ($eta$), collision centrality ($mathrm{cent}$) and beam energy ($sqrt{s_{NN}}$) which could serve as important constraints to test different initial-state models and to aid precision extraction of the temperature dependence of the specific shear viscosity.
{"title":"Beam energy dependence of the anisotropic flow coefficients v$_n$","authors":"N. Magdy","doi":"10.22323/1.311.0005","DOIUrl":"https://doi.org/10.22323/1.311.0005","url":null,"abstract":"Recent STAR measurements of the anisotropic flow coefficients, v$_{n}$, are presented for Au+Au collisions spanning the beam energy range $sqrt{s_{NN}} = 7.7 - 200$~GeV. The measurements indicate dependences on harmonic number, $n$, transverse momentum ($p_T$), pseudorapidity ($eta$), collision centrality ($mathrm{cent}$) and beam energy ($sqrt{s_{NN}}$) which could serve as important constraints to test different initial-state models and to aid precision extraction of the temperature dependence of the specific shear viscosity.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82228349","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 : 2018-01-16DOI: 10.1142/S2010194518600297
A. Austregesilo
GlueX at Jefferson Lab aims to study the light meson spectrum with an emphasis on the search for light hybrid mesons. To this end, a linearly-polarized $9,$GeV photon beam impinges on a hydrogen target contained within a hermetic detector with near-complete neutral and charged particle coverage. In 2016, the experiment completed its commissioning and subsequently started to take data in its design configuration. With the size of the data set so far, GlueX already exceeds previous experiments for polarized photoproduction in this energy regime. A selection of early results will be presented, focusing on beam asymmetries for pseudo-scalar and vector mesons. The potential to make significant contributions to the field of light-meson spectroscopy is highlighted by the observation of several known meson resonances. Furthermore, the strategy to map the light meson spectrum with amplitude analysis tools will be outlined.
{"title":"Light-Meson Spectroscopy at GlueX","authors":"A. Austregesilo","doi":"10.1142/S2010194518600297","DOIUrl":"https://doi.org/10.1142/S2010194518600297","url":null,"abstract":"GlueX at Jefferson Lab aims to study the light meson spectrum with an emphasis on the search for light hybrid mesons. To this end, a linearly-polarized $9,$GeV photon beam impinges on a hydrogen target contained within a hermetic detector with near-complete neutral and charged particle coverage. In 2016, the experiment completed its commissioning and subsequently started to take data in its design configuration. With the size of the data set so far, GlueX already exceeds previous experiments for polarized photoproduction in this energy regime. A selection of early results will be presented, focusing on beam asymmetries for pseudo-scalar and vector mesons. The potential to make significant contributions to the field of light-meson spectroscopy is highlighted by the observation of several known meson resonances. Furthermore, the strategy to map the light meson spectrum with amplitude analysis tools will be outlined.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90432211","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 : 2018-01-16DOI: 10.1142/S0217751X18430029
C. Alduino, K. Alfonso, F. Avignone, O. Azzolini, G. Bari, F. Bellini, G. Benato, A. Bersani, M. Biassoni, A. Branca, C. Brofferio, C. Bucci, A. Caminata, A. Campani, L. Canonica, X. Cao, S. Capelli, L. Cappelli, L. Cardani, P. Carniti, N. Casali, L. Cassina, D. Chiesa, N. Chott, M. Clemenza, S. Copello, C. Cosmelli, O. Cremonesi, R. Creswick, J. S. Cushman, A. D’Addabbo, D. D'Aguanno, I. Dafinei, C. Davis, S. Dell’Oro, M. Deninno, S. Domizio, M. Vacri, V. Dompè, A. Drobizhev, D. Fang, M. Faverzani, E. Ferri, F. Ferroni, E. Fiorini, M. Franceschi, S. Freedman, B. Fujikawa, Andrea Giachero, L. Gironi, A. Giuliani, L. Gladstone, P. Gorla, C. Gotti, T. Gutierrez, K. Han, K. Heeger, R. Hennings-Yeomans, H. Huang, G. Keppel, Y. Kolomensky, A. Leder, C. Ligi, K. Lim, Y. Ma, L. Marini, M. Martinez, R. Maruyama, Y. Mei, N. Moggi, S. Morganti, S. Nagorny, T. Napolitano, M. Nastasi, C. Nones, E. Norman, V. Novati, A. Nucciotti, I. Nutini, T. O’Donnell, J. Ouellet, C. Pagliarone, M. Pallavicini, V. Palmieri, L. Patt
TeO2 bolometers have been used for many years to search for neutrinoless double beta decay in 130-Te. CUORE, a tonne-scale TeO2 detector array, recently published the most sensitive limit on the half-life, $T_{1/2}^{0nu} > 1.5 times 10^{25},$yr, which corresponds to an upper bound of $140-400$~meV on the effective Majorana mass of the neutrino. While it makes CUORE a world-leading experiment looking for neutrinoless double beta decay, it is not the only study that CUORE will contribute to in the field of nuclear and particle physics. As already done over the years with many small-scale experiments, CUORE will investigate both rare decays (such as the two-neutrino double beta decay of 130-Te and the hypothesized electron capture in 123-Te), and rare processes (e.g., dark matter and axion interactions). This paper describes some of the achievements of past experiments that used TeO2 bolometers, and perspectives for CUORE.
{"title":"Study of Rare Nuclear Processes with CUORE","authors":"C. Alduino, K. Alfonso, F. Avignone, O. Azzolini, G. Bari, F. Bellini, G. Benato, A. Bersani, M. Biassoni, A. Branca, C. Brofferio, C. Bucci, A. Caminata, A. Campani, L. Canonica, X. Cao, S. Capelli, L. Cappelli, L. Cardani, P. Carniti, N. Casali, L. Cassina, D. Chiesa, N. Chott, M. Clemenza, S. Copello, C. Cosmelli, O. Cremonesi, R. Creswick, J. S. Cushman, A. D’Addabbo, D. D'Aguanno, I. Dafinei, C. Davis, S. Dell’Oro, M. Deninno, S. Domizio, M. Vacri, V. Dompè, A. Drobizhev, D. Fang, M. Faverzani, E. Ferri, F. Ferroni, E. Fiorini, M. Franceschi, S. Freedman, B. Fujikawa, Andrea Giachero, L. Gironi, A. Giuliani, L. Gladstone, P. Gorla, C. Gotti, T. Gutierrez, K. Han, K. Heeger, R. Hennings-Yeomans, H. Huang, G. Keppel, Y. Kolomensky, A. Leder, C. Ligi, K. Lim, Y. Ma, L. Marini, M. Martinez, R. Maruyama, Y. Mei, N. Moggi, S. Morganti, S. Nagorny, T. Napolitano, M. Nastasi, C. Nones, E. Norman, V. Novati, A. Nucciotti, I. Nutini, T. O’Donnell, J. Ouellet, C. Pagliarone, M. Pallavicini, V. Palmieri, L. Patt","doi":"10.1142/S0217751X18430029","DOIUrl":"https://doi.org/10.1142/S0217751X18430029","url":null,"abstract":"TeO2 bolometers have been used for many years to search for neutrinoless double beta decay in 130-Te. CUORE, a tonne-scale TeO2 detector array, recently published the most sensitive limit on the half-life, $T_{1/2}^{0nu} > 1.5 times 10^{25},$yr, which corresponds to an upper bound of $140-400$~meV on the effective Majorana mass of the neutrino. While it makes CUORE a world-leading experiment looking for neutrinoless double beta decay, it is not the only study that CUORE will contribute to in the field of nuclear and particle physics. As already done over the years with many small-scale experiments, CUORE will investigate both rare decays (such as the two-neutrino double beta decay of 130-Te and the hypothesized electron capture in 123-Te), and rare processes (e.g., dark matter and axion interactions). This paper describes some of the achievements of past experiments that used TeO2 bolometers, and perspectives for CUORE.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89623535","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 NA61/SHINE experiment aims to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. For these goals a scan of the two dimensional phase diagram ($T-mu_{B}$) is being performed at the SPS by measurements of hadron production in proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of collision energy. This paper presents preliminary results from Be+Be collisions on pseudorapidity dependences of transverse momentum and multiplicity fluctuations expressed in terms of strongly intensive quantities. It is shown that non-trivial effects evolve from the Poissonian-like fluctuations for small pseudorapidity intervals with expansion of the acceptance. These fluctuations are supposed to be sensitive to the existence of the critical point. The results will be compared to the predictions from the EPOS model.
{"title":"$N-N$, $P_{T}-N$ and $P_{T}-P_{T}$ fluctuations in nucleus-nucleus collisions at the NA61/SHINE experiment","authors":"E. Andronov","doi":"10.18502/KEN.V3I1.1748","DOIUrl":"https://doi.org/10.18502/KEN.V3I1.1748","url":null,"abstract":"The NA61/SHINE experiment aims to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. For these goals a scan of the two dimensional phase diagram ($T-mu_{B}$) is being performed at the SPS by measurements of hadron production in proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of collision energy. This paper presents preliminary results from Be+Be collisions on pseudorapidity dependences of transverse momentum and multiplicity fluctuations expressed in terms of strongly intensive quantities. It is shown that non-trivial effects evolve from the Poissonian-like fluctuations for small pseudorapidity intervals with expansion of the acceptance. These fluctuations are supposed to be sensitive to the existence of the critical point. The results will be compared to the predictions from the EPOS model.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84921687","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}
K. Abe, K. Hiraide, K. Ichimura, Y. Kishimoto, K. Kobayashi, M. Kobayashi, S. Moriyama, M. Nakahata, T. Norita, H. Ogawa, Katsuhiko Sato, H. Sekiya, O. Takachio, A. Takeda, S. Tasaka, M. Yamashita, B. Yang, N. Y. Kim, Y. Kim, Y. Itow, K. Kanzawa, R. Kegasa, K. Masuda, H. Takiya, K. Fushimi, G. Kanzaki, K. Martens, Yoshihiro Suzuki, B. D. Xu, R. Fujita, K. Hosokawa, K. Miuchi, N. Oka, Y. Takeuchi, Y. H. Kim, K. Lee, M. Lee, Y. Fukuda, M. Miyasaka, K. Nishijima, S. Nakamura
We conducted an improved search for the simultaneous capture of two $K$-shell electrons on the $^{124}$Xe and $^{126}$Xe nuclei with emission of two neutrinos using 800.0 days of data from the XMASS-I detector. A novel method to discriminate $gamma$-ray/$X$-ray or double electron capture signals from $beta$-ray background using scintillation time profiles was developed for this search. No significant signal was found when fitting the observed energy spectra with the expected signal and background. Therefore, we set the most stringent lower limits on the half-lives at $2.1 times 10^{22}$ and $1.9 times 10^{22}$ years for $^{124}$Xe and $^{126}$Xe, respectively, with 90% confidence level. These limits improve upon previously reported values by a factor of 4.5.
我们利用xmass - 1探测器800.0天的数据，改进了在$^{124}$ Xe和$^{126}$ Xe核上同时捕获两个$K$ -壳层电子并发射两个中微子的搜索。为此，开发了一种利用闪烁时间谱从$beta$射线背景中区分$gamma$ -ray/ $X$ -ray或双电子捕获信号的新方法。将观测到的能量谱与期望信号和背景拟合时，没有发现显著信号。因此，我们为$^{124}$ Xe和$^{126}$ Xe分别设定了最严格的半衰期下限$2.1 times 10^{22}$和$1.9 times 10^{22}$年，为90年% confidence level. These limits improve upon previously reported values by a factor of 4.5.
{"title":"Improved search for two-neutrino double electron capture on $^{124}$Xe and $^{126}$Xe using particle identification in XMASS-I","authors":"K. Abe, K. Hiraide, K. Ichimura, Y. Kishimoto, K. Kobayashi, M. Kobayashi, S. Moriyama, M. Nakahata, T. Norita, H. Ogawa, Katsuhiko Sato, H. Sekiya, O. Takachio, A. Takeda, S. Tasaka, M. Yamashita, B. Yang, N. Y. Kim, Y. Kim, Y. Itow, K. Kanzawa, R. Kegasa, K. Masuda, H. Takiya, K. Fushimi, G. Kanzaki, K. Martens, Yoshihiro Suzuki, B. D. Xu, R. Fujita, K. Hosokawa, K. Miuchi, N. Oka, Y. Takeuchi, Y. H. Kim, K. Lee, M. Lee, Y. Fukuda, M. Miyasaka, K. Nishijima, S. Nakamura","doi":"10.1093/ptep/pty053","DOIUrl":"https://doi.org/10.1093/ptep/pty053","url":null,"abstract":"We conducted an improved search for the simultaneous capture of two $K$-shell electrons on the $^{124}$Xe and $^{126}$Xe nuclei with emission of two neutrinos using 800.0 days of data from the XMASS-I detector. A novel method to discriminate $gamma$-ray/$X$-ray or double electron capture signals from $beta$-ray background using scintillation time profiles was developed for this search. No significant signal was found when fitting the observed energy spectra with the expected signal and background. Therefore, we set the most stringent lower limits on the half-lives at $2.1 times 10^{22}$ and $1.9 times 10^{22}$ years for $^{124}$Xe and $^{126}$Xe, respectively, with 90% confidence level. These limits improve upon previously reported values by a factor of 4.5.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91027657","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}
Bose-Einstein correlations of identical hadrons reveal information about hadron creation from the strongly interacting matter formed in ultrarelativistic heavy ion collisions. The measurement of three-particle correlations may in particular shed light on hadron creation mechanisms beyond thermal/chaotic emission. In this paper we show the status of PHENIX measurements of three pion correlations as a function of momentum differences within the triplets. We analyze the shape of the correlation functions through the assumption of L'evy sources and a proper treatment of the Coulomb interaction within the triplets. We measure the three-particle correlation strength ($lambda_3$), which, together with the two-particle correlation strength $lambda_2$, encodes information about hadron creation mechanisms. From a consistent analysis of two- and three-particle correlation strength we establish a new experimental measure of thermalization and coherence in the source.
{"title":"PHENIX results on three-particle Bose-Einstein correlations in $sqrt{S_{NN}} = 200$ GeV Au+Au collisions","authors":"T. Novak","doi":"10.3390/UNIVERSE4030057","DOIUrl":"https://doi.org/10.3390/UNIVERSE4030057","url":null,"abstract":"Bose-Einstein correlations of identical hadrons reveal information about hadron creation from the strongly interacting matter formed in ultrarelativistic heavy ion collisions. The measurement of three-particle correlations may in particular shed light on hadron creation mechanisms beyond thermal/chaotic emission. In this paper we show the status of PHENIX measurements of three pion correlations as a function of momentum differences within the triplets. We analyze the shape of the correlation functions through the assumption of L'evy sources and a proper treatment of the Coulomb interaction within the triplets. We measure the three-particle correlation strength ($lambda_3$), which, together with the two-particle correlation strength $lambda_2$, encodes information about hadron creation mechanisms. From a consistent analysis of two- and three-particle correlation strength we establish a new experimental measure of thermalization and coherence in the source.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82052617","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 : 2018-01-09DOI: 10.1103/PhysRevC.97.044311
J. Henderson, A. Chester, G. Ball, R. Caballero-Folch, T. Domingo, T. Drake, L. Evitts, G. Hackman, S. Hallam, A. Garnsworthy, M. Moukaddam, P. Ruotsalainen, J. Smallcombe, J. Smith, K. Starosta, C. Svensson, J. Williams
The evolution of nuclear magic numbers at extremes of isospin is a topic at the forefront of contemporary nuclear physics. $N=50$ is a prime example, with increasing experimental data coming to light on potentially doubly-magic $^{100}$Sn and $^{78}$Ni at the proton-rich and proton-deficient extremes, respectively. Experimental discrepancies exist in the data for less exotic systems. In $^{86}$Kr the $B(E2;2^+_1rightarrow0^+_1)$ value - a key indicator of shell evolution - has been experimentally determined by two different methodologies, with the results deviating by $3sigma$. Here, we report on a new high-precision measurement of this value, as well as the first measured lifetimes and hence transition strengths for the $2^+_2$ and $3^-_{(2)}$ states in the nucleus. The Doppler-shift attenuation method was implemented using the TIGRESS gamma-ray spectrometer and TIGRESS integrated plunger (TIP) device. High-statistics Monte-Carlo simulations were utilized to extract lifetimes in accordance with state-of-the-art methodologies. Lifetimes of $tau(2^+_1)=336pm4text{(stat.)}pm20text{(sys.)}$ fs, $tau(2^+_2)=263pm9text{(stat.)}pm19text{(sys.)}$ fs and $tau(3^-_{(2)})=73pm6text{(stat.)}pm32text{(sys.)}$ fs were extracted. This yields a transition strength for the first-excited state of $B(E2;2^+_1rightarrow0^+)=259pm3text{(stat.)}pm16text{(sys.)}$ e$^2$fm$^4$. The measured lifetime disagrees with the previous Doppler-shift attenuation method measurement by more than $3sigma$, while agreeing well with a previous value extracted from Coulomb excitation. The newly extracted $B(E2;2^+_1rightarrow0^+_1)$ value indicates a more sudden reduction in collectivity in the $N=50$ isotones approaching $Z=40$.
同位旋极值核幻数的演化是当代核物理学界的前沿课题。$N=50$就是一个最好的例子，越来越多的实验数据揭示了潜在的双重魔力$^{100}$ Sn和$^{78}$ Ni分别处于质子丰富和质子缺乏的极端。对于不那么奇特的系统，实验数据中存在差异。在$^{86}$ Kr中，$B(E2;2^+_1rightarrow0^+_1)$值——壳演化的关键指标——已经用两种不同的方法实验确定，结果偏差为$3sigma$。在这里，我们报告了对该值的一种新的高精度测量，以及首次测量的寿命和因此在原子核中$2^+_2$和$3^-_{(2)}$态的跃迁强度。采用TIGRESS伽玛能谱仪和TIGRESS集成柱塞(TIP)装置实现了多普勒频移衰减方法。利用高统计蒙特卡罗模拟，按照最先进的方法提取寿命。提取$tau(2^+_1)=336pm4text{(stat.)}pm20text{(sys.)}$ fs、$tau(2^+_2)=263pm9text{(stat.)}pm19text{(sys.)}$ fs和$tau(3^-_{(2)})=73pm6text{(stat.)}pm32text{(sys.)}$ fs的生命周期。这就得到了$B(E2;2^+_1rightarrow0^+)=259pm3text{(stat.)}pm16text{(sys.)}$ e $^2$ fm $^4$第一激发态的跃迁强度。测量的寿命与先前的多普勒频移衰减方法测量的寿命不一致$3sigma$以上，而与先前从库仑激发中提取的值吻合得很好。新提取的$B(E2;2^+_1rightarrow0^+_1)$值表明，在接近$Z=40$的$N=50$等音中，集体度的减少更为突然。
{"title":"Lifetimes of low-lying excited states in $^{86}_{36}$Kr$_{50}$","authors":"J. Henderson, A. Chester, G. Ball, R. Caballero-Folch, T. Domingo, T. Drake, L. Evitts, G. Hackman, S. Hallam, A. Garnsworthy, M. Moukaddam, P. Ruotsalainen, J. Smallcombe, J. Smith, K. Starosta, C. Svensson, J. Williams","doi":"10.1103/PhysRevC.97.044311","DOIUrl":"https://doi.org/10.1103/PhysRevC.97.044311","url":null,"abstract":"The evolution of nuclear magic numbers at extremes of isospin is a topic at the forefront of contemporary nuclear physics. $N=50$ is a prime example, with increasing experimental data coming to light on potentially doubly-magic $^{100}$Sn and $^{78}$Ni at the proton-rich and proton-deficient extremes, respectively. Experimental discrepancies exist in the data for less exotic systems. In $^{86}$Kr the $B(E2;2^+_1rightarrow0^+_1)$ value - a key indicator of shell evolution - has been experimentally determined by two different methodologies, with the results deviating by $3sigma$. Here, we report on a new high-precision measurement of this value, as well as the first measured lifetimes and hence transition strengths for the $2^+_2$ and $3^-_{(2)}$ states in the nucleus. The Doppler-shift attenuation method was implemented using the TIGRESS gamma-ray spectrometer and TIGRESS integrated plunger (TIP) device. High-statistics Monte-Carlo simulations were utilized to extract lifetimes in accordance with state-of-the-art methodologies. Lifetimes of $tau(2^+_1)=336pm4text{(stat.)}pm20text{(sys.)}$ fs, $tau(2^+_2)=263pm9text{(stat.)}pm19text{(sys.)}$ fs and $tau(3^-_{(2)})=73pm6text{(stat.)}pm32text{(sys.)}$ fs were extracted. This yields a transition strength for the first-excited state of $B(E2;2^+_1rightarrow0^+)=259pm3text{(stat.)}pm16text{(sys.)}$ e$^2$fm$^4$. The measured lifetime disagrees with the previous Doppler-shift attenuation method measurement by more than $3sigma$, while agreeing well with a previous value extracted from Coulomb excitation. The newly extracted $B(E2;2^+_1rightarrow0^+_1)$ value indicates a more sudden reduction in collectivity in the $N=50$ isotones approaching $Z=40$.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84454444","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 NA61/SHINE experiment aims to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. These goals are to be achieved by performing a two dimensional phase diagram $(T-mu_B)$ scan by measurements of hadron production properties in proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of collision energy and system size. In this contribution, the results on two-particle correlations in pseudorapidity and azimuthal angle will be presented for the first time for Be+Be interactions at beam momenta: 20, 30, 40, 75 and 150 GeV/c per nucleon. The NA61/SHINE results will be compared with the already presented results of proton-proton collisions at similar beam momenta as well as to the EPOS model results
{"title":"Two-particle correlations in azimuthal angle and pseudorapidity in Be+Be : arXiv","authors":"B. Maksiak","doi":"10.22323/1.311.0067","DOIUrl":"https://doi.org/10.22323/1.311.0067","url":null,"abstract":"The NA61/SHINE experiment aims to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. These goals are to be achieved by performing a two dimensional phase diagram $(T-mu_B)$ scan by measurements of hadron production properties in proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of collision energy and system size. In this contribution, the results on two-particle correlations in pseudorapidity and azimuthal angle will be presented for the first time for Be+Be interactions at beam momenta: 20, 30, 40, 75 and 150 GeV/c per nucleon. The NA61/SHINE results will be compared with the already presented results of proton-proton collisions at similar beam momenta as well as to the EPOS model results","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75842494","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}
Basic ideas, methods and results related to the NA61/SHINE study of event-by-event fluctuations in high energy nuclear collisions are briefly reviewed.
简要介绍了NA61/SHINE研究高能核碰撞中逐事件波动的基本思路、方法和结果。
{"title":"Fluctuations and correlations from NA61/SHINE","authors":"M. Gazdzicki","doi":"10.22323/1.311.0012","DOIUrl":"https://doi.org/10.22323/1.311.0012","url":null,"abstract":"Basic ideas, methods and results related to the NA61/SHINE study of event-by-event fluctuations in high energy nuclear collisions are briefly reviewed.","PeriodicalId":8464,"journal":{"name":"arXiv: Nuclear Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82639914","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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