The dynamical effects on electron-positron pair creation from a vacuum caused by the switching processes of a super- critical well potential are investigated in detail. The results show that only when the switching on...The dynamical effects on electron-positron pair creation from a vacuum caused by the switching processes of a super- critical well potential are investigated in detail. The results show that only when the switching on and switching off time both increase will the final pair yield converge to the integer of embedded bound states nearly exponentially. But a single adiabatic switching on or switching off cannot lead to an integer pair yield. If the potential is turned on abruptly, associated with the discrete and embedded bound states, there is multi-frequency oscillation around the pair number＇s saturation. The slowly switching on can suppress the amplitude of this oscillation and reduce the final pair yield. The switching off can also reduce the final pair number in the same order of magnitude. The evolution of a single-pair number shows a robust long range correlation between particle and antiparticle. For an adiabatic switching case, the single-pair dominates the early pair creation, their upper limit value is equal to the integer, and these single-pairs will totally disentangle during the switching off.展开更多
We investigate the electron-positron creation process from multiple equally spaced distributed oscillating electric fields.The computational quantum field theory(CQFT)is applied to analyze the effect of the number of ...We investigate the electron-positron creation process from multiple equally spaced distributed oscillating electric fields.The computational quantum field theory(CQFT)is applied to analyze the effect of the number of local fields,the distance between them,and their potential height on the created particle number.It is found that whether adjacent electric fields overlap plays an important role.The creation rate exhibits a direct linear relationship with the number of fields when they do not overlap,but exceeds the sum of the rate when the fields alone.They exhibit a distinctly nonlinear relationship when they overlap,and in particular exhibit a quadratic relationship when the fields completely overlap.These phenomena corroborate that the particle pair creation in the interaction region is non-uniform and influenced by the strength of the central strongest electric field.展开更多
The combination of an oscillating and a static field is used to study the creation and annihilation phenomena during the pair creation process.The time evolution,spatial density and momentum distribution of the create...The combination of an oscillating and a static field is used to study the creation and annihilation phenomena during the pair creation process.The time evolution,spatial density and momentum distribution of the created particles for a fermionic system are presented,which demonstrate that with the increasing static field intensity,the number of the created particles experiences a distinguishable decrease in every period of the oscillating field,which is caused by the annihilation phenomena between the created electrons and positrons.展开更多
The paper suggests that E = mc<sup>2</sup> may be open to misinterpretation and that in this form it is not what Einstein advanced first. It is further suggested to return to the slightly less compact form...The paper suggests that E = mc<sup>2</sup> may be open to misinterpretation and that in this form it is not what Einstein advanced first. It is further suggested to return to the slightly less compact formula E = Kmc<sup>2</sup> where a < K < 1 which has the merit of accounting for the measured ordinary energy density of the cosmos (K = 1/22) and the conjectured missing dark energy density of the universe (K = 21/22) from the view point of economical notation.展开更多
We adopt the quark pair creation model to investigate the light meson emissions of several charmoniumlike states.The quark pair creation model is applied to four-body systems,and we calculate the pion/kaon emissions o...We adopt the quark pair creation model to investigate the light meson emissions of several charmoniumlike states.The quark pair creation model is applied to four-body systems,and we calculate the pion/kaon emissions of X(4700),Z_(c)(4430),Y(4230),Y(4360),Y(4390),and Y(4660)within compact tetraquark configurations.We find that the pion/kaon decay widths of X(4700)and Z_(c)(4430)the resonances Y(4230),Y(4360),Y(4390),and Y(4660)cay behaviors will provide useful information for future experimental searches and theoretical interpretations.展开更多
Compared with the charmed baryons, the bottom baryons are not very well known, either experimentally Or theoretically. In this paper, we investigate the dipion strong decays of the P-wave and D-wave excited bottom bar...Compared with the charmed baryons, the bottom baryons are not very well known, either experimentally Or theoretically. In this paper, we investigate the dipion strong decays of the P-wave and D-wave excited bottom baryons in the framework of the QPC model. We also extend the same analysis to the charmed baryons.展开更多
A new generation of high power laser facilities will provide laser pulses with extremely high powers of 10 petawatt(PW)and even 100 PW, capable of reaching intensities of 1023 W/cm^2 in the laser focus. These ultra-hi...A new generation of high power laser facilities will provide laser pulses with extremely high powers of 10 petawatt(PW)and even 100 PW, capable of reaching intensities of 1023 W/cm^2 in the laser focus. These ultra-high intensities are nevertheless lower than the Schwinger intensity IS= 2.3×1029 W/cm^2 at which the theory of quantum electrodynamics(QED) predicts that a large part of the energy of the laser photons will be transformed to hard Gamma-ray photons and even to matter, via electron–positron pair production. To enable the investigation of this physics at the intensities achievable with the next generation of high power laser facilities, an approach involving the interaction of two colliding PW laser pulses is being adopted. Theoretical simulations predict strong QED effects with colliding laser pulses of 10 PW focused to intensities 10^(22) W/cm^2.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11725417 and 11575027)NSAF(Grant No.U1730449)the Science Challenge Project(Grant No.TZ2018005)
文摘The dynamical effects on electron-positron pair creation from a vacuum caused by the switching processes of a super- critical well potential are investigated in detail. The results show that only when the switching on and switching off time both increase will the final pair yield converge to the integer of embedded bound states nearly exponentially. But a single adiabatic switching on or switching off cannot lead to an integer pair yield. If the potential is turned on abruptly, associated with the discrete and embedded bound states, there is multi-frequency oscillation around the pair number＇s saturation. The slowly switching on can suppress the amplitude of this oscillation and reduce the final pair yield. The switching off can also reduce the final pair number in the same order of magnitude. The evolution of a single-pair number shows a robust long range correlation between particle and antiparticle. For an adiabatic switching case, the single-pair dominates the early pair creation, their upper limit value is equal to the integer, and these single-pairs will totally disentangle during the switching off.
基金the National Natural Science Foundation of China(Grant Nos.11974419,11605286,and 12204001)the National Key R&D Program of China(Grant No.2018YFA0404802)。
文摘We investigate the electron-positron creation process from multiple equally spaced distributed oscillating electric fields.The computational quantum field theory(CQFT)is applied to analyze the effect of the number of local fields,the distance between them,and their potential height on the created particle number.It is found that whether adjacent electric fields overlap plays an important role.The creation rate exhibits a direct linear relationship with the number of fields when they do not overlap,but exceeds the sum of the rate when the fields alone.They exhibit a distinctly nonlinear relationship when they overlap,and in particular exhibit a quadratic relationship when the fields completely overlap.These phenomena corroborate that the particle pair creation in the interaction region is non-uniform and influenced by the strength of the central strongest electric field.
基金the National Natural Science Foundation of China(Grant Nos.11974419 and 11605286)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA25051000)the National Key R&D Program of China(Grant No.2018YFA0404802)。
文摘The combination of an oscillating and a static field is used to study the creation and annihilation phenomena during the pair creation process.The time evolution,spatial density and momentum distribution of the created particles for a fermionic system are presented,which demonstrate that with the increasing static field intensity,the number of the created particles experiences a distinguishable decrease in every period of the oscillating field,which is caused by the annihilation phenomena between the created electrons and positrons.
文摘The paper suggests that E = mc<sup>2</sup> may be open to misinterpretation and that in this form it is not what Einstein advanced first. It is further suggested to return to the slightly less compact formula E = Kmc<sup>2</sup> where a < K < 1 which has the merit of accounting for the measured ordinary energy density of the cosmos (K = 1/22) and the conjectured missing dark energy density of the universe (K = 21/22) from the view point of economical notation.
基金Supported by the National Natural Science Foundation of China(11705056,12175037,11947224,11475192,11975245,U1832173)the Key Project of Hunan Provincial Education Department under(21A0039)+3 种基金the State Scholarship Fund of China Scholarship Council(22006725011)the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”project by NSFC(12070131001)the Key Research Program of Frontier Sciences,CAS(Y7292610K1)the National Key Research and Development Program of China(2020YFA0406300)。
文摘We adopt the quark pair creation model to investigate the light meson emissions of several charmoniumlike states.The quark pair creation model is applied to four-body systems,and we calculate the pion/kaon emissions of X(4700),Z_(c)(4430),Y(4230),Y(4360),Y(4390),and Y(4660)within compact tetraquark configurations.We find that the pion/kaon decay widths of X(4700)and Z_(c)(4430)the resonances Y(4230),Y(4360),Y(4390),and Y(4660)cay behaviors will provide useful information for future experimental searches and theoretical interpretations.
基金Supported by National Natural Science Foundation of China(11222547,11175073,11035006,11375240,11261130311)Ministry of Education of China(FANEDD(200924)+2 种基金DPFIHE(20090211120029)NCET(NCET-10-0442)Fundamental Research Funds for Central Universities
文摘Compared with the charmed baryons, the bottom baryons are not very well known, either experimentally Or theoretically. In this paper, we investigate the dipion strong decays of the P-wave and D-wave excited bottom baryons in the framework of the QPC model. We also extend the same analysis to the charmed baryons.
基金support from the National Key Research and Development Program of China(No.2016YFA0300803)support from the Project of Shanghai HIgh repetition rate XFEL aNd Extreme light facility(SHINE)+13 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB16)support from the EPSRC,UK(Nos.EP/L013975 and EP/N022696/1)support from Extreme Light Infrastructure Nuclear Physics(ELI-NP) Phase IIa project co-financed by the Romanian Government and the European Union through the European Regional Development Fundsupport from EPSRC(No.EP/M018091/1)support from EPSRC(No.EP/M018555/1)STFC(Nos.ST/J002062/1 and ST/P002021/1)Horizon2020 funding from the European Research Council(ERC)(No.682399)support from the National Natural Science Foundation of China(Nos.11622547,11875319,11875091,11474360,and 11175255)the National Key Research and Development Program of China(No.2018YFA0404802)the Science Challenge Program(No.TZ2016005)the Hunan Province Science and Technology Program of China(No.2017RS3042)supported by the National Natural Science Foundation of China(Nos.11347028,11405083,and 11675075)UK Engineering and Physics Sciences Research Council(Nos.EP/G054940/1,EP/G055165/1,and EP/G056803/1)
文摘A new generation of high power laser facilities will provide laser pulses with extremely high powers of 10 petawatt(PW)and even 100 PW, capable of reaching intensities of 1023 W/cm^2 in the laser focus. These ultra-high intensities are nevertheless lower than the Schwinger intensity IS= 2.3×1029 W/cm^2 at which the theory of quantum electrodynamics(QED) predicts that a large part of the energy of the laser photons will be transformed to hard Gamma-ray photons and even to matter, via electron–positron pair production. To enable the investigation of this physics at the intensities achievable with the next generation of high power laser facilities, an approach involving the interaction of two colliding PW laser pulses is being adopted. Theoretical simulations predict strong QED effects with colliding laser pulses of 10 PW focused to intensities 10^(22) W/cm^2.
