一个新的矢量玻色子的存在已经在不同的背景下被提出,这个新矢量玻色子与标准模型粒子的耦合可以通过动力学混合,对U玻色子,或者通过耦合到重子数,对B玻色子.暗物质传播子的直接寻找可以在加速器上进行.DANEΦ-工厂中的KLOE探测器大...一个新的矢量玻色子的存在已经在不同的背景下被提出,这个新矢量玻色子与标准模型粒子的耦合可以通过动力学混合,对U玻色子,或者通过耦合到重子数,对B玻色子.暗物质传播子的直接寻找可以在加速器上进行.DANEΦ-工厂中的KLOE探测器大量研究了U玻色子参与的两种过程:介子的达利兹衰变,即伴随→ηU,U→e+e-过程,以及连续统事件e+e-→Uγ过程.在所有这些过程中,对于质量区间在4 Me V/c2<MU<980 Me V/c2,我们可以给出U玻色子耦合参数ε2上限在10-7到10-5.KLOE也在暗希格斯辐射过程e+e-→U h',U→μ+μ-中寻找U玻色子,mU和mh'在参数空间中被分别限定在2mμ<mU<1 000 Me V/c2和10 Me V/c2<mh'<500 Me V/c2的范围内.同时新的数据采集已经在KLOE-2设备上运行,未来3年采集目标将在5 fb-1以上.新的大数据样本将进一步提高暗耦合常数的上限.展开更多
In the framework of the relativistic mean field theory including the hyperon-hyperon(YY) interactions,protoneutron stars with a weakly interacting light U boson are studied. The U-boson leads to the increase of the st...In the framework of the relativistic mean field theory including the hyperon-hyperon(YY) interactions,protoneutron stars with a weakly interacting light U boson are studied. The U-boson leads to the increase of the star maximum mass. The modification to the maximum mass by the U-boson with the strong YY interaction is larger than that with the weak YY interaction. The maximum mass of the protoneutron star is less sensitive to the U-boson than that of the neutron star. The inclusion of the U-boson narrows down the mass window for the hyperonized protoneutron stars. As g^2/μ~2 increases, the species of hyperons, which can appear in a stable protoneutron star decrease. The rotation frequency, the red shift, the momentum of inertia and the total neutrino fraction of PSR J1903-0327 are sensitive to the U-boson and change with g^2/μ~2 in an approximate linear trend. The possible way to constrain the coupling constants of the U-boson is discussed.展开更多
Considering the octet baryons in relativistic mean field theory and selecting entropy per baryon S=1, we calculate and discuss the influence of U bosons on the equation of state, mass-radius, moment of inertia and gra...Considering the octet baryons in relativistic mean field theory and selecting entropy per baryon S=1, we calculate and discuss the influence of U bosons on the equation of state, mass-radius, moment of inertia and gravitational redshift of massive protoneutron stars （PNSs）. The effective coupling constant gu of U bosons and nucleons is selected from 0 to 70 GeV-2. The results indicate that U bosons will stiffen the equation of state （EOS）. The influence of U bosons on the pressure is more obvious at low density than high density, while the influence of U bosons on the energy density is more obvious at high density than low density. The U bosons play a significant role in increasing the maximum mass and radius of PNS. When the value of gu changes from 0 to 70 GeV-2, the maximum mass of a massive PNS increases from 2.11M to 2.58Me, and the radius of a PNS corresponding to PSR J0348＋0432 increases from 13.71 km to 24.35 km. The U bosons will increase the moment of inertia and decrease the gravitational redshift of a PNS. For the PNS of the massive PSR J0348＋0432, the radius and moment of inertia vary directly with gu, and the gravitational redshift varies approximately inversely with gu.展开更多
基金Supported in part by the EU Integrated Infrastructure Initiative Hadron Physics Project(RII3-CT-2004-506078)the European Commission under the 7th Framework Programme through the “Research Infrastructures” Action of the “Capacities” Programme FP7-INFRASTRUCTURES-2008-1(227431)the Polish National Science Centre(2011/03/N/ST2/02652,2013/08/M/ST2/00323,2013/11/B/ST2/04245,2014/14/E/ST2/00262,2014/12/S/ST2/00459
文摘一个新的矢量玻色子的存在已经在不同的背景下被提出,这个新矢量玻色子与标准模型粒子的耦合可以通过动力学混合,对U玻色子,或者通过耦合到重子数,对B玻色子.暗物质传播子的直接寻找可以在加速器上进行.DANEΦ-工厂中的KLOE探测器大量研究了U玻色子参与的两种过程:介子的达利兹衰变,即伴随→ηU,U→e+e-过程,以及连续统事件e+e-→Uγ过程.在所有这些过程中,对于质量区间在4 Me V/c2<MU<980 Me V/c2,我们可以给出U玻色子耦合参数ε2上限在10-7到10-5.KLOE也在暗希格斯辐射过程e+e-→U h',U→μ+μ-中寻找U玻色子,mU和mh'在参数空间中被分别限定在2mμ<mU<1 000 Me V/c2和10 Me V/c2<mh'<500 Me V/c2的范围内.同时新的数据采集已经在KLOE-2设备上运行,未来3年采集目标将在5 fb-1以上.新的大数据样本将进一步提高暗耦合常数的上限.
基金Supported by Jiangsu Province Natural Science Foundation Youth Fund of China under Grant No.Bk20140982National Natural Science Foundation of China under Grant No.11447165+1 种基金Youth Innovation Promotion Association,Chinese Academy of Sciences under Grant No.2016056the Development Project of Science and Technology of Jilin Province under Grant No.20180520077JH
文摘In the framework of the relativistic mean field theory including the hyperon-hyperon(YY) interactions,protoneutron stars with a weakly interacting light U boson are studied. The U-boson leads to the increase of the star maximum mass. The modification to the maximum mass by the U-boson with the strong YY interaction is larger than that with the weak YY interaction. The maximum mass of the protoneutron star is less sensitive to the U-boson than that of the neutron star. The inclusion of the U-boson narrows down the mass window for the hyperonized protoneutron stars. As g^2/μ~2 increases, the species of hyperons, which can appear in a stable protoneutron star decrease. The rotation frequency, the red shift, the momentum of inertia and the total neutrino fraction of PSR J1903-0327 are sensitive to the U-boson and change with g^2/μ~2 in an approximate linear trend. The possible way to constrain the coupling constants of the U-boson is discussed.
基金Supported by National Natural Science Foundation of China(11175147)
文摘Considering the octet baryons in relativistic mean field theory and selecting entropy per baryon S=1, we calculate and discuss the influence of U bosons on the equation of state, mass-radius, moment of inertia and gravitational redshift of massive protoneutron stars （PNSs）. The effective coupling constant gu of U bosons and nucleons is selected from 0 to 70 GeV-2. The results indicate that U bosons will stiffen the equation of state （EOS）. The influence of U bosons on the pressure is more obvious at low density than high density, while the influence of U bosons on the energy density is more obvious at high density than low density. The U bosons play a significant role in increasing the maximum mass and radius of PNS. When the value of gu changes from 0 to 70 GeV-2, the maximum mass of a massive PNS increases from 2.11M to 2.58Me, and the radius of a PNS corresponding to PSR J0348＋0432 increases from 13.71 km to 24.35 km. The U bosons will increase the moment of inertia and decrease the gravitational redshift of a PNS. For the PNS of the massive PSR J0348＋0432, the radius and moment of inertia vary directly with gu, and the gravitational redshift varies approximately inversely with gu.
