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Abstract
A neutron star was first detected as a pulsar in 1967. It is one of the most mysterious compact objects in the universe, with a radius of the order of 10 km and masses that can reach two solar masses. In fact, neutron stars are star remnants, a kind of stellar zombie (they die, but do not disappear). In the last decades, astronomical observations yielded various contraints for neutron star masses, and finally, in 2017, a gravitational wave was detected (GW170817). Its source was identified as the merger of two neutron stars coming from NGC 4993, a galaxy 140 million light years away from us. The very same event was detected in γ-ray, X-ray, UV, IR, radio frequency and even in the optical region of the electromagnetic spectrum, starting the new era of multi-messenger astronomy. To understand and describe neutron stars, an appropriate equation of state that satisfies bulk nuclear matter properties is necessary. GW170817 detection contributed with extra constraints to determine it. On the other hand, magnetars are the same sort of compact object, but bearing much stronger magnetic fields that can reach up to 1015 G on the surface as compared with the usual 1012 G present in ordinary pulsars. While the description of ordinary pulsars is not completely established, describing magnetars poses extra challenges. In this paper, I give an overview on the history of neutron stars and on the development of nuclear models and show how the description of the tiny world of the nuclear physics can help the understanding of the cosmos, especially of the neutron stars.
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Cusanno F, Urciuoli GM, Acha A, Ambrozewicz P, Aniol KA, Baturin P, Bertin PY, Benaoum H, Blomqvist KI, Boeglin WU, Breuer H, Brindza P, Bydzovský P, Camsonne A, Chang CC, Chen JP, Choi S, Chudakov EA, Cisbani E, Colilli S, Coman L, Craver BJ, De Cataldo G, de Jager CW, De Leo R, Deur AP, Ferdi C, Feuerbach RJ, Folts E, Fratoni R, Frullani S, Garibaldi F, Gayou O, Giuliani F, Gomez J, Gricia M, Hansen JO, Hayes D, Higinbotham DW, Holmstrom TK, Hyde CE, Ibrahim HF, Iodice M, Jiang X, Kaufman LJ, Kino K, Kross B, Lagamba L, LeRose JJ, Lindgren RA, Lucentini M, Margaziotis DJ, Markowitz P, Marrone S, Meziani ZE, McCormick K, Michaels RW, Millener DJ, Miyoshi T, Moffit B, Monaghan PA, Moteabbed M, Muñoz Camacho C, Nanda S, Nappi E, Nelyubin VV, Norum BE, Okasyasu Y, Paschke KD, Perdrisat CF, Piasetzky E, Punjabi VA, Qiang Y, Raue B, Reimer PE, Reinhold J, Reitz B, Roche RE, Rodriguez VM, Saha A, Santavenere F, Sarty AJ, Segal J, Shahinyan A, Singh J, Sirca S, Snyder R, Solvignon PH, Sotona M, Subedi R, Sulkosky VA, Suzuki T, Ueno H, Ulmer PE, Veneroni P, Voutier E, Wojtsekhowski BB, Zheng X, Zorn C. High-resolution spectroscopy of Lambda16N by electroproduction. PHYSICAL REVIEW LETTERS 2009; 103:202501. [PMID: 20365979 DOI: 10.1103/physrevlett.103.202501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 09/14/2009] [Indexed: 05/29/2023]
Abstract
An experimental study of the (16)O(e,e'K(+))(Lambda)(16)N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K(+))Lambda, Sigma(0) exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76+/-0.16 MeV was obtained for (Lambda)(16)N with better precision than previous measurements on the mirror hypernucleus (Lambda)(16)O. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p(1/2) and p(3/2) hole states of the (15)N core nucleus.
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Affiliation(s)
- F Cusanno
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Piazzale Aldo Moro 2, I-00185 Rome, Italy
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Saha PK, Fukuda T, Imoto W, Ahn JK, Ajimura S, Aoki K, Bhang HC, Fujioka H, Hotchi H, Hwang JI, Itabashi T, Kang BH, Kim HD, Kim MJ, Kishimoto T, Krutenkova A, Maruta T, Miura Y, Miwa K, Nagae T, Noumi H, Outa H, Ohtaki T, Sakaguchi A, Sato Y, Sekimoto M, Shimizu Y, Tamura H, Tanida K, Toyoda A, Ukai M, Yim HJ. Production of the neutron-rich hypernucleus 10LambdaLi in the (pi-,K+) double charge-exchange reaction. PHYSICAL REVIEW LETTERS 2005; 94:052502. [PMID: 15783631 DOI: 10.1103/physrevlett.94.052502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Indexed: 05/24/2023]
Abstract
In order to produce a neutron-rich Lambda hypernucleus for the first time, we carried out an experiment by utilizing the (pi-,K+) double charge-exchange reaction on a 10B target. We observed the production of a 10LambdaLi hypernucleus. The cross section for the Lambda bound region was found to be 11.3+/-1.9 nb/sr with the 1.2 GeV/c incident momentum, which is compared with the 10LambdaB hypernucleus production cross section, 7.8+/-0.3 microb/sr, in the (pi+,K+) reaction with a 1.05 GeV/c incident momentum beam.
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Affiliation(s)
- P K Saha
- Osaka Electro-Communication University, Neyagawa, Osaka 572-8530, Japan
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Ajimura S, Hayakawa H, Kishimoto T, Kohri H, Matsuoka K, Minami S, Mori T, Morikubo K, Saji E, Sakaguchi A, Shimizu Y, Sumihama M, Chrien RE, May M, Pile P, Rusek A, Sutter R, Eugenio P, Franklin G, Khaustov P, Paschke K, Quinn BP, Schumacher RA, Franz J, Fukuda T, Noumi H, Outa H, Gan L, Tang L, Yuan L, Tamura H, Nakano J, Tamagawa T, Tanida K, Sawafta R. Observation of spin-orbit splitting in lambda single-particle states. PHYSICAL REVIEW LETTERS 2001; 86:4255-4258. [PMID: 11328148 DOI: 10.1103/physrevlett.86.4255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2000] [Indexed: 05/23/2023]
Abstract
The spin-orbit splitting of Lambda single-particle states in (13)(Lambda)C was measured. The 13C(K-,pi(-))(13)(Lambda)C reaction was used to excite both the 1/2(-) and 3/2(-) states simultaneously, which have predominantly 12C(0(+)) x p(Lambda) configuration. gamma rays from the states to the ground state were measured in coincidence with the pi(-)'s, by which ls splitting was found to be 152+/-54(stat)+/-36(syst) keV. The value is 20-30 times smaller than exhibited by the ls splitting in the nuclear shell model. This value gives us new insight into the YN interaction.
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Affiliation(s)
- S Ajimura
- Department of Physics, Osaka University, Toyonaka, Osaka, 560-0043, Japan
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Hasegawa T, Hashimoto O, Homma S, Miyachi T, Nagae T, Sekimoto M, Shibata T, Sakaguchi H, Takahashi T, Aoki K, Noumi H, Bhang H, Youn M, Gavrilov Y, Ajimura S, Kishimoto T, Ohkusu A, Maeda K, Sawafta R, Redwine RP. Spectroscopic study of Lambda 10B, Lambda 12C, Lambda 28Si, Lambda 89Y, Lambda 139La, and Lambda 208Pb by the ( pi +,K+) reaction. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1996; 53:1210-1220. [PMID: 9971056 DOI: 10.1103/physrevc.53.1210] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Yamazaki H, Maeda K, Asano S, Emura T, Endo S, Ito S, Itoh H, Konno O, Maruyama K, Niwa K, Sakaguchi A, Suda T, Sumi Y, Takeya M, Terasawa T, Yamashita H. The 12C( gamma,K+) reaction in the threshold region. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 52:R1157-R1160. [PMID: 9970679 DOI: 10.1103/physrevc.52.r1157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Usmani AA, Pieper SC, Usmani QN. Variational calculations of the Lambda -separation energy of the Lambda 17O hypernucleus. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 51:2347-2355. [PMID: 9970315 DOI: 10.1103/physrevc.51.2347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Kishimoto T, Ajimura S, Ejiri H, Nakamura F, Noumi H, Higashi A, Inoue G, Gill DR, Lee L, Olin A, Yen S. Lambda -nucleon interaction in nuclei probed by the quasifree 12C( pi +,K+) reaction. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 51:2233-2236. [PMID: 9970296 DOI: 10.1103/physrevc.51.2233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Hasegawa T, Hashimoto O, Homma S, Miyachi T, Nagae T, Sekimoto M, Shibata T, Sakaguchi H, Takahashi T, Aoki K, Noumi H, Bhang H, Youn M, Gavrilov Y, Ajimura S, Kishimoto T, Ohkusu A, Maeda K, Sawafta R, Redwine RP. Core-excited states of Lambda 12C hypernuclei formed in the ( pi +,K+) reaction. PHYSICAL REVIEW LETTERS 1995; 74:224-227. [PMID: 10058334 DOI: 10.1103/physrevlett.74.224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Itonaga K, Motoba T, Sotona M. The (K−,π−) and (π+, K+) Reactions and Λ-Hypernuclear Polarization. ACTA ACUST UNITED AC 1994. [DOI: 10.1143/ptps.117.17] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The theoretical studies of (K−, π−) and (π+, K+) reactions on p-shell targets are presented in the DWIA framework with use of the elementary spin-nonflip and spin-flip amplitudes. Calculations can explain the available experimental data of excitation functions and angular distributions of the (K−, π−) reactions at pK−=800 MeV/c and the (π+, K+) reactions at pπ+ = 1.04 GeV/c. Characteristic and distinguished features of the excitation functions and cross sections are exhibited. Especially it is demonstrated that the (K−, π−) reactions at pK−=1.1 GeV/c and 1.5 GeV/c can excite the unnatural parity states with comparable strength to the natural parity ones. Further interesting is that the (π+, K+) and (K−, π−) reactions with ∼1 GeV/c incident beams can be shown to produce very large polarizations of the produced hypernuclear states. Taking the subsequent deexcitation processes of the excited states into account, we have evaluated the hypernuclear polarization and Λ-spin polarization of the ground state and/or the ground-doublet states at the hypernuclear weak-decay stage, which would play a role in the hypernuclear coincidence experiment.
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Affiliation(s)
- K. Itonaga
- Laboratory of Physics, Miyazaki Medical College, Kiyotake, Miyazaki 889-16
| | - T. Motoba
- Laboratory of Physics, Osaka Electro-Communication University, Neyagawa 572
| | - M. Sotona
- Nuclear Physics Institute, Czech Academy of Sciences, 250 68 Řež, Prague
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Lalazissis GA. Dependence on the mass number of energy quantities of a Lambda in hypernuclei with the cosh and the Gaussian potential. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1994; 49:1412-1421. [PMID: 9969364 DOI: 10.1103/physrevc.49.1412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Itonaga K, Motoba T, Richter O, Sotona M. Hypernuclear and Lambda -spin polarizations produced in the ( pi +,K+) reaction. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1994; 49:1045-1058. [PMID: 9969313 DOI: 10.1103/physrevc.49.1045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Lalazissis GA. Analytic expressions for the Lambda energy in the lower nodeless Lambda single particle states. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1993; 48:198-204. [PMID: 9968811 DOI: 10.1103/physrevc.48.198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Ajimura S, Ejiri H, Higashi A, Inoue G, Iseki Y, Kishimoto T, Nakamura F, Noumi H, Ohsumi H, Sano H, Gill DR, Lee L, Olin A, Yen S, Fukuda T, Hashimoto O, Shibata T, Nomachi M, Kimura Y, Maeda K. Polarization of Lambda hyperons produced by the quasifree ( pi +,K+) reaction on 12C. PHYSICAL REVIEW LETTERS 1992; 68:2137-2140. [PMID: 10045318 DOI: 10.1103/physrevlett.68.2137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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