Gaussian modification of neutrino energy loss on strongly screening nuclides ~（55）Co and ~（56）Ni by electron capture in stellar interior

Gaussian modifications of the neutrino energy loss (NEL) by electron capture on the strongly screening nuclides ⁵⁵Co and ⁵⁶Ni are investigated. The results show that in strong electron screening (SES), the NEL rates decrease without modifying the Gamow-Teller (G-T) resonance transition. For instance, the NEL rates of ⁵⁵Co and ⁵⁶Ni decrease more than two and three orders of magnitude for ρ₇=5.86, T₉≤5, Y_e=0.47, Δ=6.3, respectively. In contrast, due to Gaussian modification, the NEL rates increase about two orders of magnitude in SES. Due to SES, the maximum values of the C-factor (in %) on NEL of ⁵⁵Co, ⁵⁶Ni are of the order of 99.80%, 99.56% at ρ₇=5.86 Y_e=0.47 and 99.60%, 99.65% at ρ₇=106 Y_e=0.43, respectively.     

Neutrino energy loss by electron capture on strongly screened iron group nuclei

The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of $15\ti10^9$\,K, the neutrino energy loss rates which come from the electron capture process for most iron group nuclei decrease no more than 2 orders of magnitude but for the others (such as $^{53,55,56,57,58,59,60}$Co, $^{56,59}$Ni) they can decrease about 3 orders of magnitude due to strong electron screening (SES), whereas, at a temperature of $10^9K$ the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, $^{61}$Fe, $^{60}$Fe, and $^{62}$Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for $^{57}$Cr, $^{58}$Cr, and $^{60}$Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei $^{58}$Mn, $^{59}$Mn, $^{60}$Mn, and $^{62}$Mn may decrease about 13 orders of magnitude at a temperature of $10^9$\,K due to the SES.     

Bremsstrahlung neutrino energy loss for ^24Mg, ^28Si, ^32S, ^40Ca, ^56Fe in strong electron screening

Based on Weinberg-Salam theory the bremsstrahlung neutrino energy loss for nuclei ^24Mg, ^28Si,^32S, ^40Ca and ^56Fe are investigated in strong electron screening. Our results are compared with those of Dicus＇ and show that the latter are higher by 2 orders of magnitude in the density-temperature region of 10^8 g/cm^3 ≤p/μe ≤ 10^11 g/cm^3 and 2.5≤ T9≤ 4.5. On the other hand, the factor C shows that the maximum differences are 99.16%, 99.13%, 99.12%, 99.055%, 99.040% corresponding to the nuclei ^24Mg, ^28Si, ^32S, ^40Ca and ^56Fe.     

Bremsstrahlung neutrino energy loss for ~(24)Mg, ~(28)Si, ~(32)S, ~(40)Ca, ~(56)Fe in strong electron screening

Based on WeinbergoSalam theory the bremsstrahlung neutrino energy loss for nuclei ~(24)Mg, ~(28)Si, ~(32)S, ~(40)Ca and ~(56)Fe are investigated in strong electron screening. Our results are compared with those of Dicus' and show that the latter are higher by 2 orders of magnitude in the density-temperature region of 10~8 g/cm~3 ≤ρ/μ_e≤10~(11) g/cm~3 and 2.5 ≤ T_9 ≤4.5. On the other hand, the factor C shows that the maximum differences are 99.16%, 99.13%, 99.12%, 99.055%, 99.040% corresponding to the nuclei ~(24)Mg, ~(28)Si, ~(32)S, ~(40)Ca and ~(56)Fe.     

Bremsstrahlung neutrino energy loss for ~(24)Mg,~(28)Si,~(32)S,~(40)Ca,~(56)Fe in strong electron screening

Based on Weinberg-Salam theory the bremsstrahlung neutrino energy loss for nuclei 24Mg,28Si,32S,40Ca and 56Fe are investigated in strong electron screening.Our results are compared with those of Dicus' and show that the latter are higher by 2 orders of magnitude in the density-temperature region of 108 g/cm3 ρ/μe 1011 g/cm3 and 2.5 T9 4.5.On the other hand,the factor C shows that the maximum differences are 99.16%,99.13%,99.12%,99.055%,99.040% corresponding to the nuclei 24Mg,28Si,32S,40Ca and 56Fe.     

Pair neutrino energy loss for nuclei 56Fe at the late stages of stellar evolution

Based on the Weinberg-Salam theory,the pair neutrino energy loss rates for nuclei 56Fe are canvassed for the wide range of density and temperature.The results of ours (QLJ) are compared with those of Beaudet G,Petrosian V and Salpeter E.E's (QBPS),and it shows that the pair neutrino energy loss rates of QBPS are always larger than QLJ .The QBPS is 12.57%,12.86%,14.99%,19.80% times higher than QLJ corresponding to the temperature T9=0.385,1.0,5.0,10,respectively.     

Pair neutrino energy loss for nuclei 56^Fe at the late stages of stellar evolution

Based on the Weinberg-Salam theory, the pair neutrino energy loss rates for nuclei 56Fe are can- vassed for the wide range of density and temperature. The results of ours (QLJ) are compared with those of Beaudet G, Petrosian V and Salpeter E. E's (QBPS), and it shows that the pair neutrino energy loss rates of QBPS are always larger than QLJ .The QBPS is 12.57%, 12.86%, 14.99%, 19.80% times higher than QLJ corresponding to the temperature T9=0.385, 1.0, 5.0, 10, respectively.     

Beta decay of nuclide 56Fe,56Co,56Ni,56Mn,56Cr and 56V due to strong electron screening in stellar interiors

According to a new electron screening theory,we discuss the beta decay rates of nuclide 56Fe,56Co,56Ni,56Mn,56Cr and 56V with and without strong electron screening (SES).The results show that SES has only a slight effect on the beta decay rates for ρ/μe 108 g/cm3.However the beta decay rates would be influenced greatly for ρ/μe 108 g/cm3.Due to SES,the maximum values of the C-factor (in %) on beta decay rates of 56Fe,56Co,56Ni,56Mn,56Cr and 56V is of the order of 95.03%,35.02%,98.05%,80.33%,98.30% and 98.71% at T9 = 4.0 and 98.83%,98.89%,99.65%,10.32%,4.10% and 40.21% at T9 = 7.0,respectively.     

Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars

Based on the p-f shell model, the effect of strong magnetic field on neutrino energy loss rates by electron capture is investigated. The calculations show that the magnetic field has only a slight effect on the neutrino energy loss rates in the range of 10⁸—10¹³G on the surfaces of most neutron stars. But for some magnetars, the range of the magnetic field is 10¹³—10¹⁸G, and the neutrino energy loss rates are greatly reduced, even by more than four orders of magnitude due to the strong magnetic field.     

Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars

Based on the p-f shell model,the effect of strong magnetic field on neutrino energy loss rates by electron capture is investigated.The calculations show that the magnetic field has only a slight effect on the neutrino energy loss rates in the range of 108-1013 G on the surfaces of most neutron stars.But for some magnetars,the range of the magnetic field is 1013-1018 G,and the neutrino energy loss rates are greatly reduced,even by more than four orders of magnitude due to the strong magnetic field.     

束缚电子对7Be太阳中微子流量的影响

计算了在太阳核心从R=0到R=0.125R⊙处,7Be存在1个或2个K壳层束缚电子的概率约为4.54%.这表明7Be原子俘获的电子95.46%是自由电子.假定太阳中微子自产生后没有发生任何改变,并且太阳的其他参量不改变,那么7Be和8B太阳中微子流量的理论计算值分别约为4.04×109和6.12×106cm-2s-1.这将进一步扩大8B太阳中微子与superKamiokande太阳中微子实验测量值之间的差距 关键词： K壳层束缚电子 电子俘获概率 7Be太阳中微子流量 8B太阳中微子流量     

Plasma neutrino energy loss due to the axial-vector current at the late stages of stellar evolution

Based on the Weinberg-Salam theory, the plasma neutrino energy loss rates of vector and axialvector contributions are studied.A ratable factor of the rates from the axial-vector current relative to those of the total neutrino energy loss rates is accurately calculated.The results show that the ratable factor will reach a maximum of 0.95 or even more at relatively higher temperature and lower density (such as P/μe＜ 10~7 g/cm~3).Thus the rates of the axial-vector contribution cannot be neglected.On the other hand, the rates of the axialvector contribution are on the order of～0.01% of the total vector contribution, which is in good agreement with Itoh's at relatively high density (such as p/μe＞10~7 g/cm~3) and a temperature of T≤10~(11) K.     

Effects of ultra-strong magnetic field on electron capture rates of~(55)Co and ~(56)Ni in the magnetar surrounding

The electron capture rates of~(55)Co and~(56)Ni in the ultra-strong magnetic field at four typical temperaturedensity points have been calculated using the nuclear shell model and Landau energy levels quantized approximate correction.The results show that the electron capture rates of~(55)Co and~(56)Ni are increased greatly in the ultra-strong magnetic field,and even exceed two orders of magnitude in the range from 4.414×10~(13)G to 2.207×l0~(17)G.The change rate of electron abundance,Y_e,of~(55)Co and~(56)Ni under the condition of B=4.414×l0~(15)G in the magnetar surrounding has been calculated and discussed,the proportions of Y_e of~(55)Co and~(56)Ni in the total Y_e have been reduced by 50percent in all more than the condition without a magnetic field.     

Plasma neutrino energy loss due to the axial-vector current at the late stages of stellar evolution

Based on the Weinberg-Salam theory, the plasma neutrino energy loss rates of vector and axialvector contributions are studied. A ratable factor of the rates from the axial-vector current relative to those of the total neutrino energy loss rates is accurately calculated. The results show that the ratable factor will reach a maximum of 0.95 or even more at relatively higher temperature and lower density （such as p/μe 〈 10^7 g/cm^3）. Thus the rates of the axial-vector contribution cannot be neglected. On the other hand, the rates of the axialvector contribution are on the order of ~0.01% of the total vector contribution, which is in good agreement with Itoh＇s at relatively high density （such as p/μe 〉 10^7 g/cm^3） and a temperature of T ≤ 10^11 K.     

Effects of ultra-strong magnetic field on electron capture rates of 55C0 and 56Ni in the magnetar surrounding

The electron capture rates of 55Co and 56Ni in the ultra-strong magnetic field at four typical temperature- density points have been calculated using the nuclear shell model and Landan energy levels quantized approximate correction. The results show that the electron capture rates of 55Co and 56Ni are increased greatly in the ultra-strong magnetic field, and even exceed two orders of magnitude in the range from 4.414×10^13G to 2.207×10^27 G. The change rate of electron abundance, ye, of 55Co and 56Ni under the condition of B=4.414×10^15G in the magnetar surrounding has been calculated and discussed, the proportions of ye of 55Co and 56Ni in the total Ye have been reduced by 50 percent in all more than the condition without a magnetic field.     

电荷屏蔽对快中子俘获过程的影响

本文计算在初生中子星中微子驱动的星风环境中弱电荷屏蔽对质子电子俘获反应的影响.结果表明电荷屏蔽对星风中核子的比加热率、熵等物理参量基本没有影响.但是可以明显提高电子丰度,而这种提高有力地支持了最新的快中子俘获核合成结果.     

Parton energy loss in strongly coupled AdS/CFT

This is a brief review of the theory and phenomenology of parton energy loss in strongly coupled field theories with a gravity dual and its comparison with parton energy loss in QCD at weak coupling.     

Effect of strong magnetic field on chemical potential and electron capture in magnetar

The chemical potential of electrons in a strong magnetic field is investigated. It is shown that the magnetic field has only a slight effect on electron chemical potential when B 〈 10^11 T, but electron chemical potential will decrease greatly when B 〉 10^11 T. The effects of a strong magnetic field on electron capture rates for ^60Fe are discussed, and the result shows that the electron capture sharply decreases because of the strong magnetic field.     

弱电离大气等离子体电子碰撞能量损失的理论研究

在前期计算电子能量分布函数的基础上, 求出弱电离大气等离子体中各碰撞反应过程的电子能量损失. 由于在弹性碰撞中电子-重粒子能量交换很少, 同时氮气、氧气分子又有很多能量阈值较低的转动、振动能级存在, 因此在大气等离子体中弹性碰撞电子能量损失所占份额很小(直流电场下小于6%). 研究发现, 弱电离大气等离子体中在不同能量区间占主导的能量损失过程不同. 随着有效电子温度(或约化场强)增加, 占主导的电子能量损失过程依次为转动激发、振动激发、电子态激发、碰撞电离、加速电离产生的二次电子. 在约化场强E/N=1350 Td (或有效电子温度为14 eV)附近, 平均电离一个电子所需的能量最小, 约为57 eV. 因此可以根据不同的需求调节电场强度, 从而达到较高的能量利用率. 关键词： 弱电离大气等离子体 碰撞反应过程 电子能量损失     

Multiple ionization of argon accompanied by electron loss and capture of 0.22-6.35 MeV C^q＋ ions

In this paper a projectile ions recoil ions coincidence technique is employed to investigate the target ionization and projectile charge state changing processes in the collision of 0.22-6.35 MeV Cq^＋ （q = 1 - 4） ions with argon atoms. The partial cross section ratios of the double, triple, quadruplicate ionization to the single ionization （or the single capture） of argon associated with single electron loss （or single electron capture） by the projectile are measured and compared with the previous experimental results. In the present experiment, it is observed that the ratios of ionization cross sections R associated with single loss and single capture depend strongly on the projectile charge state and vary significantly with different reaction channels as impact energy increases. In addition, this paper gets empirical scaling laws for the ionization cross section ratios R corresponding to the projectile single loss and finds that the ratios of the double ionization to the single ionization associated with single electron capture remain constant in the present energy range.