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1.
Abstract In recent years, a nonzero value for the neutrino mixing angle θ13 has been successively measured by the international famous reactor oscillation experiments, which is greater than 5 standard deviations. Our study is in the framework of the MSSM, where baryon and lepton numbers are local gauged symmetries (BLMSSM). This model can generate three tiny neutrino masses at the tree level through TeV scale seesaw mechanism. In our paper, we analyze the neutrino masses and their corresponding mixing angles with a "top-down" method, assuming neutrino mass spectrum with normal ordering (NO) and inverted ordering (IO).  相似文献   

2.
In an extension of the standard model, where baryon number and lepton number are local gauge sym- metries, we analyze the effect of corrections from exotic fermions and scalars on the oblique parameters S, T, U. Because a light neutral Higgs h0 with mass around 12-126 GeV strongly constrains the corresponding parameter space of this model, we also investigate the gluon fusion process gg→h0 and two photon decay of the lightest neutral Higgs h0→yy at the Large Hadron Collider.  相似文献   

3.
In an extension of the standard model,where baryon number and lepton number are local gauge symmetries,we analyze the effect of corrections from exotic fermions and scalars on the oblique parameters S,T,U.Because a light neutral Higgs ho with mass around 124-126 GeV strongly constrains the corresponding parameter space of this model,we also investigate the gluon fusion process gg→h_0 and two photon decay of the lightest neutral Higgs ho→γγ at the Large Hadron Collider.  相似文献   

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5.
In this paper, we calculate the top quark rare decays t →cγ and v in an extension of the standard model, where baryon number and lepton number are local gauge symmetries. Adopting reasonable assumptions on the parameter space, we find that the branching ratios of t →cγ and t →cg can reach 10^-6 and 10^-5 respectively, which can be detected in near future.  相似文献   

6.
We briefly review the issues related to electroweak baryogenesis in minimal supersymmetric standard model (MSSM). The constraints from electric dipole moments of electron and neutron are emphasized.  相似文献   

7.
指出在轻子诱发反应中测量产生超子的极化是研究高能强子化过程自旋转移的理想途径.在总结这些反应产生的初始夸克或反夸克极化的基础上,给出了超子极化的计算方法.作为应用举例,给出了e+e湮没过程中LEP能量下各种超子的极化及与已有实验的比较.这些结果表明,测量各类超子的极化可作为检验不同的重子自旋结构图像,何者适用于高能碎裂过程的重要手段.  相似文献   

8.
This review article is concerned with three topics important for the construction of four‐dimensional models of particle physics in the context of type II String Theories. Special emphasis is put on a consistent presentation of these topics as well as on highlighting their interconnections. The first of the three topics deals with the tadpole cancellation conditions and the cancellation of chiral anomalies for type IIB orientifolds with orientifold three‐ and seven‐planes. The second topic is related to non‐perturbative effects originating from D‐brane instantons. In particular, in the presence of a realistic particle physics sector, a chiral zero‐mode constraint for contribution of instantons to the superpotential arises. The third topic is about moduli stabilisation in type IIB string compactifications. Two scenarios, the KKLT and Large Volume Scenario, are reviewed and a model for the latter scenario with the chiral zero‐mode constraint taken into account is presented.  相似文献   

9.
用带有弦集体相互作用和再散射的Fritiof程序新版,计算了S(200GeV/c)+Pb反应中奇异重子与反重子的比值.和的理论值和相应实验数据,在实验数据彼此偏差的范围内相符合.这表明:奇异重子与反重子的比值在强子背景下可能得到解释.  相似文献   

10.
Treating the cosmological constant as a dynamical variable, we investigate the thermodynamics and weak cosmic censorship conjecture(WCCC) of a charged Ad S black hole(BH) in the Rastall gravity. We determine the energy momentum relation of charged fermion at the horizon of the BH using the Dirac equation. Based on this relation, it is shown that the first law of thermodynamics still holds as a fermion is absorbed by the BH. However, the entropy of both the extremal and near-extremal BH decreases in the irreversible process, which means that the second law of thermodynamics is violated.Furthermore, we verify the validity of the WCCC by the minimum values of the metric function h(r) at its final state. For the extremal charged Ad S BH in the Rastall gravity, we find that the WCCC is always valid since the BH is extreme. While for the case of near-extremal BH, we find that the WCCC could be violable in the extended phase space(EPS), depending on the value of the parameters of the BH and their variations.  相似文献   

11.
In this paper, we study a theory of gravity called mimetic f(R, T) in the presence of swampland dS conjecture. For this purpose, we introduce several inflation solutions of the Hubble parameter H(N) from f(R, T) = R + δT gravity model, in which R is Ricci scalar, and T denotes the trace of the energy–momentum tensor. Also, δ and N are the free parameter and a number of e-fold, respectively. Then we calculate quantities such as potential, Lagrange multiplier, slow-roll, and some cosmological parameters such as ns and r. Then we challenge the mentioned inflationary model from the swampland dS conjecture. We discuss the stability of the model and investigate the compatibility or incompatibility of this inflationary scenario with the latest Planck observable data.  相似文献   

12.
The existence of exotic couplings in the weak interaction can be tested by a precise measurement of the β-ν angular correlation parameter a in nuclear beta decay. In the case of 6He, the ratio of tensor and axial-vector couplings can be determined. The goal of the LPC Trap experiment is to improve the limits on the existence of tensor currents. The LPCTrap setup is installed on the low energy beam line LIRAT of the SPIRAL/GANIL facility. The 6He+ ions are confined in a novel transparent Paul trap allowing the detection in coincidence of both the β-particle and the recoil ion. The detection setup enables to detect the position and energy of these two particles. The a parameter can then be extracted from the time of flight spectrum of the recoil ions. The first 6He+ decay events were observed in May 2005 during a commissioning run. Over 105 coincidence events have been recorded during a second run in July 2006.  相似文献   

13.
14.
We implement a schizophrenic scenario for the active neutrinos in a model in which there are also exotic right-handed neutrinos making a model with a local U(1)BLU(1)BL anomaly free. Two of right-handed neutrinos carry B−L=−4BL=4 while the third one carries B−L=5BL=5. Unlike the non-exotic version of the model, in which all right-handed neutrinos carry the same B−L=−1BL=1 charge, in this case the neutrinos have their own scalar sector and no hierarchy in the Yukawa coupling in the Dirac mass term is necessary.  相似文献   

15.
We perform a comparative Monte Carlo study of the easy-plane deconfined critical point (DCP) action and its short-range counterpart to reveal close similarities between the two models for intermediate and strong coupling regimes. For weak coupling, the structure of the phase diagram depends on the interaction range: while the short-range model features a tricritical point and a continuous U(1) × U(1) transition, the long-range DCP action is characterized by the runaway renormalization flow of coupling into a first (I) order phase transition. We develop a “numerical flowgram” method for high precision studies of the runaway effect, weakly I-order transitions, and polycritical points. We prove that the easy-plane DCP action is the field theory of a weakly I-order phase transition between the valence bond solid and the easy-plane antiferromagnet (or superfluid, in particle language) for any value of the weak coupling strength. Our analysis also solves the long standing problem of what is the ultimate fate of the runaway flow to strong coupling in the theory of scalar electrodynamics in three dimensions with U(1) × U(1) symmetry of quartic interactions.  相似文献   

16.
As a charged fermion drops into a BTZ black hole, the laws of thermodynamics and the weak cosmic censorship conjecture are investigated in both the normal and extended phase space, where the cosmological parameter and renormalization length are regarded as extensive quantities. In the normal phase space, the first and second law of thermodynamics, and the weak cosmic censorship are found to be valid. In the extended phase space, although the first law and weak cosmic censorship conjecture remain valid, the second law is dependent on the variation of the renormalization energy d K. Moreover, in the extended phase space, the configurations of extremal and near-extremal black holes are not changed, as they are stable, while in the normal phase space, the extremal and near-extremal black holes evolve into non-extremal black holes.  相似文献   

17.
陈西浩  王秀娟 《物理学报》2018,67(19):190301-190301
应用矩阵乘积态表示的无限虚时间演化块算法,研究了扩展的量子罗盘模型.为了深入研究该模型的长程拓扑序和量子相变,基于奇数键和偶数键,引入了奇数弦关联和偶数弦关联,计算了保真度、奇数弦关联、偶数弦关联、奇数弦关联饱和性与序参量.弦关联表现出三种截然不同的行为:衰减为零、单调饱和与振荡饱和.基于弦关联的以上特征,给出了量子罗盘模型的基态序参量相图.在临界区,局域磁化强度和单调奇弦序参量的临界指数β=1/8表明:相变的普适类是Ising类型.此外,保真度探测到的相变点、连续性与非连续性和序参量的结果一致.  相似文献   

18.
Summary We have measured the reflectivity spectra of monocrystalline ZnTe, CdTe and HgTe between 5 and 35 eV. We have interpreted the sharp structures above approximately 10 eV as transitions originating in the metal uppermostd levels. The structures give a picture of the projected densities of states of the conduction bands and supply a better understanding of their states.
Riassunto Abbiamo misurato gli spettri di riflettività di monocristalli di ZnTe, CdTe ed HgTe tra 5 e 35 eV. Oltre i 10 eV gli spettri presentano delle strutture fini, interpretate come transizioni che hanno origine nei livellid piú alti del catione. Questa interpretazione permette di ricavare una rappresentazione schematica della densità proiettata degli stati di conduzione e di ottenere una migliore comprensione sulla natura degli stati finali stessi.
  相似文献   

19.
In this work, we study the theory of inflation with the non-minimally coupled quadratic, standard model Higgs, and hilltop potentials, through ξφ~2R term in Palatini gravity. We first analyze observational parameters of the Palatini quadratic potential as functions of ξ for the high-N scenario. In addition to this, taking into account that the inflaton field f has a non-zero vacuum expectation value v after inflation, we display observational parameters of well-known symmetry-breaking potentials. The types of potentials considered are the Higgs potential and its generalizations, namely hilltop potentials in the Palatini formalism for the high-N scenario and the low-N scenario. We calculate inflationary parameters for the Palatini Higgs potential as functions of v for different ξ values, where inflaton values are both φv and φv during inflation, as well as calculating observational parameters of the Palatini Higgs potential in the induced gravity limit for high-N scenario. We illustrate differences between the Higgs potential's effect on ξ versus hilltop potentials, which agree with the observations for the inflaton values for φv and ξ, in which v1 for both these high and low N scenarios. For each considered potential, we also display n_s-r values fitted to the current data given by the Keck Array/BICEP2 and Planck collaborations.  相似文献   

20.
In this review article we give a brief overview on some recent progress in quark pairings in dense quark/nuclear matter mostly developed in the past five years.We focus on following aspects in particular:the BCS-BEC crossover in the CSC phase,the baryon formation and dissociation in dense quark/nuclear matter,the Ginzburg-Landau theory for three-flavor dense matter with UA(1) anomaly,and the collective and Nambu-Goldstone modes for the spin-one CSC.  相似文献   

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